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  • 301.
    Silvestri, Laura
    et al.
    Rome Center for Molecular Design Dipartimento di Chimica e Tecnologie del Farmaco, Facolta ̀ di Farmacia e Medicina.
    Ballante, Flavio
    Rome Center for Molecular Design Dipartimento di Chimica e Tecnologie del Farmaco, Facolta ̀ di Farmacia e Medicina.
    Mai, Antonello
    Istituto Pasteur - Fondazione Cenci Bolognetti Dipartimento di Chimica e Tecnologie del Farmaco, Facolta ̀ di Farmacia e Medicina.
    Marshall, Garland R
    Rome Center for Molecular Design Dipartimento di Chimica e Tecnologie del Farmaco, Facolta ̀ di Farmacia e Medicina; Visiting Professor from the Department of Biochemistry and Molecular Biophysics, Wash ington University School of Medicine, St. Louis, Missouri 63110, United States.
    Ragno, Rino
    Rome Center for Molecular Design Dipartimento di Chimica e Tecnologie del Farmaco, Facolta ̀ di Farmacia e Medicina.
    Histone deacetylase inhibitors: structure-based modeling and isoform-selectivity prediction.2012In: Journal of Chemical Information and Modeling, ISSN 1549-9596, E-ISSN 1549-960X, Vol. 52, no 8, p. 2215-35Article in journal (Refereed)
    Abstract [en]

    An enhanced version of comparative binding energy (COMBINE) analysis, named COMBINEr, based on both ligand-based and structure-based alignments has been used to build several 3-D QSAR models for the eleven human zinc-based histone deacetylases (HDACs). When faced with an abundance of data from diverse structure-activity sources, choosing the best paradigm for an integrative analysis is difficult. A common example from studies on enzyme-inhibitors is the abundance of crystal structures characterized by diverse ligands complexed with different enzyme isoforms. A novel comprehensive tool for data mining on such inhomogeneous set of structure-activity data was developed based on the original approach of Ortiz, Gago, and Wade, and applied to predict HDAC inhibitors' isoform selectivity. The COMBINEr approach (apart from the AMBER programs) has been developed to use only software freely available to academics.

  • 302. Simmen, K. A.
    et al.
    De Kock, H. A.
    Raboisson,, P. J.
    Hu, L.
    Tahri, A.
    Surleraux,, D. L. N. G.
    Nilsson, K. M.
    Samuelsson, B. B.
    Rosenquist, Å. A. K.
    Ivanov, V.
    Pelcman, M.
    Belfrage,, Anna Karin G. L.
    Johansson, P. M.
    Vendeville,, S. M. H.
    Macrocylic inhibitors of hepatitis C virus2012Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    Inhibitors of HCV replication of formula (I)

    and the N-oxides, salts, and stereoisomers, wherein

    • each dashed line represents an optional double bond;
    • X is N, CH and where X bears a double bond it is C;
    • R1 is —OR7, —NH—SO2R8;
    • R2 is hydrogen, and where X is C or CH, R2 may also be C1-6alkyl;
    • R3 is hydrogen, C1-6alkyl, C1-6alkoxyC1-6alkyl, C3-7cycloalkyl;
    • R4 is aryl or Het; n is 3, 4, 5, or 6;
    • R5 is halo, C1-6alkyl, hydroxy, C1-6alkoxy, phenyl, or Het;
    • R6 is C1-6alkoxy, or dimethylamino;
    • R7 is hydrogen; aryl; Het; C3-7cycloalkyl optionally substituted with C1-6alkyl; or C1-6alkyl optionally substituted with C3-7cycloalkyl, aryl or with Het;
    • R8 is aryl; Het; C3-7cycloalkyl optionally substituted with C1-6alkyl; or C1-6alkyl optionally substituted with C3-7cycloalkyl, aryl or with Het;
    • aryl is phenyl optionally substituted with one, two or three substituents;
    • Het is a 5 or 6 membered saturated, partially unsaturated or completely unsaturated heterocyclic ring containing 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur, and being optionally substituted with one, two or three substituents;
    • pharmaceutical compositions containing compounds (I) and processes for preparing compounds (I). Bioavailable combinations of the inhibitors of HCV of formula (I) with ritonavir are also provided.
  • 303.
    Sjöberg, Hans
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmaceutical Chemistry.
    Release and transport of drugs in some complex and interacting systems2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Drug formulations come in many forms, some intended for direct and immediate action and others aiming at a controlled manner of drug delivery. Viewed in a more general way drug transport often involves charged units, it takes place in a medium which in many respects must be considered complex - to some degree even reactive. Drug transport may also be competitive because of thermo- and hydrodynamic interactions, These three aspects of drug transport in general is discussed and exemplified in specific studies: 1) A conductivity study as a fundamental investigation for iontophoretic drug delivery; 2) a methodological development and diffusivity investigation of a steroidal hormone transport in silica containing silicone; 3) an investigation of competitive diffusion transport of small amphiphilic molecules in a polyelectrolyte containing semi-solid system.

    Iontophoresis - drug administration by electric current - normally requires charged drug molecules, hence their mobility and state of dissociation are essential parameters. The medium in which the drug is situated regulates the electrolytic drug content (e.g. dissociation equilibrium) and thus the iontophoretic efficiency. The conductivity of the local anesthetic, IidocaineHCl was investigated by high precision conductometry in aqueous and octanol solutions. From conductivity data and applied advanced electrolyte theory drug mobility parameters as well as, dissociation and association constants were obtained. The drug ion mobility was found, to be a factor 50 lower in octanol. The equilibrium constants obtained show that increasing drug concentration favors ion formation in water while favoring ion pair association in octanol. Hence, such a drug behaves very differently in different media, with obvious clinical implications.

    The dynamic diffusion in the complex system silicone/silica/estradiol was studied by means of a new equipment design which has considerably improved the possibility to perform precise quantitative dynamic diffusion measurements in such systems, The method avoids all disturbing interfaces between different media and allows for a precise spatial resolution of concentration of the diffusing drug. Data showed the method to be dependable and accurate. The effect on estradiol diffusivity due to varied silica content in the silicone is found to be paramount, increasing [SiO2] from 17 to 30% decreased the diffusivity by 68%. Some mechanisms are discussed.

    The diffusion of amphiphiles within and the release from agarose hydrogels containing the polyelectrolyte carrageenan was investigated. All drugs exhibit same apparent diffusivity in pure agarose gel. The diffusivity decreased when carrageenan was introduced in the gel. The order of the decrease follows the order of increased hydrophobic character of the drug. Competing diffusion was studied for amitriptyline and chlorpromazine, the former released significantly faster than chlorpromazine when simultaneously released from a hydrogel slab. Data indicate the possibility to adjust the simultaneous release rates individually for the two drugs by means of polyion charge density.

  • 304.
    Sjögren, Erik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Andersson, Sara
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Sundgren-Andersson, Anna K.
    AstraZeneca R&D, Global Med Dev, SE-43183 Molndal, Sweden..
    Halldin, Magnus M.
    Karolinska Inst, AlzeCure Fdn, Sci Pk, SE-14157 Huddinge, Sweden..
    Stalberg, Olle
    Karlstad Univ, Dept Engn & Chem Sci, SE-65188 Karlstad, Sweden..
    Assessment of Free Drug Concentration in Cyclodextrin Formulations Is Essential to Determine Drug Potency in Functional In Vitro Assays2016In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 105, no 9, p. 2913-2920Article in journal (Refereed)
    Abstract [en]

    Cyclodextrins (CD) have the ability to form inclusion complexes with drugs and can be used as excipients to enhance solubility of poorly soluble drugs. To make accurate estimations of the potency of the drug, knowledge of the free drug concentration is important. The aim of this study was to evaluate the applicability of calculated free drug concentrations toward response measurements in a transient receptor potential vanilloid receptor-1 cell-based in vitro assay. This included accounting for potential competitive CD binding of 2 transient receptor potential vanilloid receptor-1 active entities: 1 antagonist, and 1 agonist (capsaicin). Solubility of the CD-drug complexes was measured, and the ligand to substrate affinity in CD formulations was determined according to the phase-solubility technique. The total concentration of antagonist, agonist, CD, and the binding constants between ligands and CD were used to calculate the free concentration of CD ligands. For capsaicin and 2 of the 3 investigated model drugs, the calculated free drug concentration was consistent with the experimental in vitro data while it was overestimated for one of the compounds. In conclusion, the suggested approach can be used to calculate free drug concentration and competitive binding in CD formulations for the application of cell-based drug functionality assays.

  • 305.
    Skogh, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Development of Substance P 1–7 Related Peptides and Peptidomimetics: Targeting Neuropathic Pain2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The neuropeptide substance P 1–7 (SP1–7, H-Arg1-Pro2-Lys3-Pro4-Gln5-Gln6-Phe7-OH) and its amidated analogue SP1–7 amide, have displayed intriguing effects in experimental models for neuropathic pain acting on a specific, yet unknown SP1–7 target. The aim of this thesis was to design and synthesise SP1–7 related peptides and peptidomimetics, to be used as research tools to study the SP1–7 system, and to serve as drug leads in the neuropathic pain area.

    The in vivo structure activity relationship (SAR) of the SP1–7 amide was elucidated using Ala-substituted, N-terminally truncated and N-methylated variants. By evaluation of the anti-allodynic effect in spared nerve injury (SNI) mice and the pharmacokinetic properties it is suggested that Phe7 acts as a message residue and Arg1 as an address residue, both important for the overall anti-allodynic activity. In contrast, Lys3 could be substituted by alanine, and the Pro2-Lys3 and Pro4-Gln5 bond could be N-methylated with retained anti-allodynic effect. The Pro2-Lys3 bond was found most sensitive towards proteolysis and indeed, N-methylation of this bond delivered peptides completely inert in plasma. Conversely, prolonged plasma stability did not improve the overall in vivo activity for these peptides. Instead, the SP1–7 amide remained the most potent peptide in vivo, despite fast degradation in plasma.    

    Besides peptide synthesis, the synthetic work included development of a Pd-catalysed aminocarbonylation protocol using an amino acid nucleophile, which was used for the synthesis of an imidazole-based peptidomimetic. This peptidomimetic was equipotent to the SP1–7 amide, and more potent than the drug gabapentin, in regard to its anti-allodynic effect in SNI mice, and it is a promising drug lead for further development. The Pd-catalysed aminocarbonylation protocol was refined further, in regards to reaction scope and requirements for solid-phase peptide synthesis and has proven useful for N-capping, isotopic labelling, and intramolecular cyclisation of peptides.

    In summary, the work presented herein resulted in an in vivo SAR for SP1–7 related peptides, a novel small molecule SP1–7 peptidomimetic, and methods expanding the toolbox for synthesising modified peptides and peptidomimetics – a field in drug discovery that presently gaining increasing attention.

    List of papers
    1. Importance of N-and C-terminal residues of substance P 1-7 for alleviating allodynia in mice after peripheral administration
    Open this publication in new window or tab >>Importance of N-and C-terminal residues of substance P 1-7 for alleviating allodynia in mice after peripheral administration
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    2017 (English)In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 106, p. 345-351Article in journal (Refereed) Published
    Abstract [en]

    The heptapeptide SP1-7 (1, Arg(1)-Pro(2)-Lys(3)-Pro(4)-Gln(5)-Gln(6)-Phe(7)) is the major bioactive metabolite formed after proteolytic processing of the neuropeptide substance P (SP, Arg(1)-Pro(2)-Lys(3)-Pro(4)-GIn(5)-Gln(6)-Phe(7)-Phe(8)-Gly(9)-Leu(10)-Meti(11)-NH2). The heptapeptide 1 frequently exhibits opposite effects to those induced by SP, such as exerting antinociception, or attenuating thermal hyperalgesia and mechanical allodynia. The heptapeptide SP1-7 amide (2, Arg(1)-Pro(2)-Lys(3)-Pro(4)-Gln(5)-Gln(6)-Phe(7)-NH2 ) is often more efficacious than 1 in experimental pain models. We have now assessed the anti-allodynic outcome after systemic administration of 2 and a series of Ala substituted and truncated analogues of 2, in the spared nerve injury (SNI) mice model and the results obtained were correlated with in vitro plasma stability and permeability measurements. It is herein demonstrated that an intact Arg(1) in SP1-7 amide analogues is fundamental for retaining a potent in vivo effect, while Lys(3) of 2 is less important. A displacement with Ala(1) or truncation rendered the peptide analogues either inactive or with a significantly attenuated in vivo activity. Thus, the pentapeptide SP3-7 amide (7, t(1/2) = 11.1 min) proven to be the major metabolite of 2, demonstrated an in vivo effect itself although considerably less significant than 2 in the SNI model. Intraperitoneal administration of 2 in a low dose furnished the most powerful anti-allodynic effect in the SNI model of all the analogous evaluated, despite a fast proteolysis of 2 in plasma (t(1/2) = 6.4 min). It is concluded that not only the C-terminal residue, that we previously demonstrated, but also the N-terminal with its basic side chain, are important for achieving effective pain relief. This information is of value for the further design process aimed at identifying more drug-like SP1-7 amide related peptidomimetics with pronounced antiallodynic effects.

    Place, publisher, year, edition, pages
    Elsevier, 2017
    Keywords
    Neuropathic pain, Spared nerve injury (SNI), SP1-7, Neuropeptides, Plasma stability, Structure-activity relationship, Message-address concept
    National Category
    Pharmacology and Toxicology
    Identifiers
    urn:nbn:se:uu:diva-334033 (URN)10.1016/j.ejps.2017.06.004 (DOI)000406988600036 ()28587787 (PubMedID)
    Available from: 2017-11-23 Created: 2017-11-23 Last updated: 2018-02-28Bibliographically approved
    2. Impact of N-methylation of the substance P 1-7 amide on anti-allodynic effect in mice after peripheral administration
    Open this publication in new window or tab >>Impact of N-methylation of the substance P 1-7 amide on anti-allodynic effect in mice after peripheral administration
    Show others...
    2017 (English)In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 109, p. 533-540, article id S0928-0987(17)30497-9Article in journal (Refereed) Published
    Abstract [en]

    Substance P 1-7 (SP1-7, Arg1-Pro2-Lys3-Pro4-Gln5-Gln6-Phe7) is the major bioactive metabolite formed after proteolytic degradation of the tachykinin substance P (SP). This heptapeptide often opposes the effects of the mother peptide. Hence, SP1-7 is having anti-inflammatory, anti-nociceptive and anti-hyperalgesic effects in experimental models. Despite all encouraging properties of SP1-7 its exact mode of action has not yet been elucidated which has hampered further development of this heptapeptide in drug discovery. Contrary to SP that mediates its biological activity via the NK-1 receptor, the N-terminal fragment SP1-7 acts through an unknown target that is distinct from all known opioid and tachykinin receptors. The SP1-7 amide 1 (Arg1-Pro2-Lys3-Pro4-Gln5-Gln6-Phe7-NH2) was previously shown to be superior to the endogenous SP1-7 in all experimental pain models where the two compounds were compared. Herein, we report that N-methylation scan of the backbone of the SP1-7 amide (1) results in peptides that are significantly less prone to undergo proteolysis in plasma from both mouse and human. However, with the two exceptions of the [MeLys3]SP1-7 amide (3) and the [MeGln5]SP1-7 amide (4), the peptides with a methyl group attached to the backbone are devoid of significant anti-allodynic effects after peripheral administration in the spared nerve injury (SNI) mouse model of neuropathic pain. It is suggested that the N-methylation does not allow these peptides to form the accurate bioactive conformations or interactions required for efficient binding to the macromolecular target. The importance of intact N-terminal Arg1 and C-terminal Phe7, anticipated to serve as address and message residues, respectively, for achieving the anti-allodynic effect is emphasized. Notably, the three heptapeptides: the SP1-7 amide (1), the [MeLys3]SP1-7 amide (3) amide and the [MeGln5]SP1-7 amide (4) are all considerably more effective in the SNI mouse model than gabapentin that is widely used in the clinic for treatment of neuropathic pain.

    Keywords
    Anti-allodynia, N-methylation, SP(1–7) amide, Solid phase peptide synthesis (SPPS), Spared nerve injury (SNI), Substance P (SP)
    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-335651 (URN)10.1016/j.ejps.2017.09.007 (DOI)000413325000055 ()28887235 (PubMedID)
    Funder
    Swedish Research Council, 9459The Swedish Brain FoundationBerzelii Centre EXSELENT
    Available from: 2017-12-07 Created: 2017-12-07 Last updated: 2018-02-28
    3. Aminocarbonylation of 4-Iodo-1H-imidazoles with an Amino Acid Amide Nucleophile: Synthesis of Constrained H-Phe-Phe-NH2 Analogues
    Open this publication in new window or tab >>Aminocarbonylation of 4-Iodo-1H-imidazoles with an Amino Acid Amide Nucleophile: Synthesis of Constrained H-Phe-Phe-NH2 Analogues
    Show others...
    2013 (English)In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 78, no 23, p. 12251-12256Article in journal (Refereed) Published
    Abstract [en]

    A simple and an expedient process to prepare 5-aryl-1benzyl-1H-imidazole-4-carboxamides by the aminocarbonylation of 5aryl-4-iodo-1H-imidazoles using ex situ generation of CO from Mo(CO)(6) with an amino acid amide nucleophile is reported. Furthermore, a microwave-assisted protocol for the direct C-5 arylation of 1-benzyl-1H-imidazole and a regioselective C-4 iodination method to acquire starting material for our aminocarbonylation are presented. The method can be used to prepare imidazole based peptidomimetics, herein exemplified by the synthesis of constrained H-Phe-Phe-NH2 analogues.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-214017 (URN)10.1021/jo4020613 (DOI)000328231600069 ()
    Available from: 2014-01-08 Created: 2014-01-07 Last updated: 2018-02-28Bibliographically approved
    4. An imidazole based H-Phe-Phe-NH2 peptidomimetic with anti-allodynic effect in spared nerve injury mice
    Open this publication in new window or tab >>An imidazole based H-Phe-Phe-NH2 peptidomimetic with anti-allodynic effect in spared nerve injury mice
    Show others...
    2018 (English)In: Bioorganic & Medicinal Chemistry Letters, ISSN 0960-894X, E-ISSN 1464-3405, Vol. 28, no 14, p. 2446-2450Article in journal (Refereed) Published
    Abstract [en]

    The dipeptide amide H-Phe-Phe-NH2 (1) that previously was identified as a ligand for the substance P 1-7 (SP1-7) binding site exerts intriguing results in animal models of neuropathic pain after central but not after peripheral administration. The dipeptide 1 is derived from stepwise modifications of the anti-nociceptive heptapeptide SP1-7 and the tetrapeptide endomorphin-2 that is also binding to the SP1-7 site. We herein report a strong anti-allodynic effect of a new H-Phe-Phe-NH2 peptidomimetic (4) comprising an imidazole ring as a bioisosteric element, in the spare nerve injury (SNI) mice model after peripheral administration. Peptidomimetic 4 was stable in plasma, displayed a fair membrane permeability and a favorable neurotoxic profile. Moreover, the effective dose (ED50) of 4 was superior as compared to gabapentin and morphine that are used in clinic.

    National Category
    Medicinal Chemistry
    Identifiers
    urn:nbn:se:uu:diva-343682 (URN)10.1016/j.bmcl.2018.06.009 (DOI)000438467200020 ()29929882 (PubMedID)
    Funder
    Swedish Research Council, 9459
    Note

    Title in dissertation reference list: An Imidazole-Based H-Phe-Phe-NH2 Peptidomimetic with Anti-Allodynic Effect in Spared Nerve Injury Mice and without Neurotoxic Liability

    Available from: 2018-02-28 Created: 2018-02-28 Last updated: 2020-06-05Bibliographically approved
    5. Palladium-Catalyzed Aminocarbonylation in Solid-Phase Peptide Synthesis: A Method for Capping, Cyclization, and Isotope Labeling
    Open this publication in new window or tab >>Palladium-Catalyzed Aminocarbonylation in Solid-Phase Peptide Synthesis: A Method for Capping, Cyclization, and Isotope Labeling
    2017 (English)In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 19, no 11, p. 2873-2876Article in journal (Refereed) Published
    Abstract [en]

    A new synthetic approach for introducing N-capping, groups onto peptides attached to a solid support, Combining aminocarbonylation under mild conditions Wing a palladacycle precatalyst and, solid-phase peptide synthesis is reported. The use of la silacarboxylic acid as an in situ CO-releasing molecule allowed the reaction to be performed single vial. The method also enables versatile substitution of side chains, side-chain to side-chain cyclizations, and selective aryl labeling of modified peptides.

    Place, publisher, year, edition, pages
    AMER CHEMICAL SOC, 2017
    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-327450 (URN)10.1021/acs.orglett.7b01068 (DOI)000402850900025 ()28498670 (PubMedID)
    Funder
    Danish National Research Foundation, DNRF118
    Available from: 2017-08-25 Created: 2017-08-25 Last updated: 2018-02-28Bibliographically approved
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  • 306.
    Skogh, Anna
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Drug Design and Discovery.
    Lesniak, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Sköld, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Drug Design and Discovery.
    Karlgren, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy.
    Gaugaz, Fabienne Z.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Svensson, Richard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmacy. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Diwakarla, Shanti
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Jonsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Fransson, Rebecca
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Nyberg, Fred
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Hallberg, Mathias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Johansson, Anja
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Drug Design and Discovery.
    An imidazole based H-Phe-Phe-NH2 peptidomimetic with anti-allodynic effect in spared nerve injury mice2018In: Bioorganic & Medicinal Chemistry Letters, ISSN 0960-894X, E-ISSN 1464-3405, Vol. 28, no 14, p. 2446-2450Article in journal (Refereed)
    Abstract [en]

    The dipeptide amide H-Phe-Phe-NH2 (1) that previously was identified as a ligand for the substance P 1-7 (SP1-7) binding site exerts intriguing results in animal models of neuropathic pain after central but not after peripheral administration. The dipeptide 1 is derived from stepwise modifications of the anti-nociceptive heptapeptide SP1-7 and the tetrapeptide endomorphin-2 that is also binding to the SP1-7 site. We herein report a strong anti-allodynic effect of a new H-Phe-Phe-NH2 peptidomimetic (4) comprising an imidazole ring as a bioisosteric element, in the spare nerve injury (SNI) mice model after peripheral administration. Peptidomimetic 4 was stable in plasma, displayed a fair membrane permeability and a favorable neurotoxic profile. Moreover, the effective dose (ED50) of 4 was superior as compared to gabapentin and morphine that are used in clinic.

  • 307.
    Slazak, Blazej
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy. Polish Acad Sci, W Szafer Inst Bot, 46 Lubicz St, PL-31512 Krakow, Poland..
    Kapusta, Malgorzata
    Univ Gdansk, Fac Biol, Dept Plant Cytol & Embryol, 59 Wita Stwosza St, PL-80308 Gdansk, Poland..
    Malik, Sohaib
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Bohdanowicz, Jerzy
    Univ Gdansk, Fac Biol, Dept Plant Cytol & Embryol, 59 Wita Stwosza St, PL-80308 Gdansk, Poland..
    Kuta, Elzbieta
    Jagiellonian Univ, Inst Bot, Dept Plant Cytol & Embryol, 9 Gronostajowa St, PL-30387 Krakow, Poland..
    Malec, Przemyslaw
    Jagiellonian Univ, Fac Biochem Biophys & Biotechnol, 7 Gronostajowa St, PL-30387 Krakow, Poland..
    Göransson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Immunolocalization of cyclotides in plant cells, tissues and organ supports their role in host defense2016In: Planta, ISSN 0032-0935, E-ISSN 1432-2048, Vol. 244, no 5, p. 1029-1040Article in journal (Refereed)
    Abstract [en]

    Main conclusionThe distribution of cyclotides was visualized in plant cells, tissues and organs using immunohistochemistry. Finding of cyclotides in tissues potentially vulnerable to pathogen attacks supports their role as defense molecules. The cyclotide family of plant peptides is characterized by the cyclic cystine knot motif and its diverse biological activities. Given their insecticidal and antimicrobial properties, the role of cyclotides in planta is probably associated with host defense. Our current understanding of the cellular compartmentalization of cyclotides in the vacuole is based on indirect studies on transgenic model plants that do not express cyclotides naturally. Matrix-assisted laser desorption ionization (MALDI) imaging has also been used to study the distribution of cyclotides, but the technique's resolution was insufficient to determine their tissue or cell distribution. To avoid the limitations of these approaches, immunohistochemical visualization methods were used. Antibodies were raised in rabbits using cycloviolacin O2 (cyO2), and their specificity was determined by Western and dot blot experiments. Slides for immunohistochemical analysis were prepared from leaf, petiole and root fragments of Viola odorata and Viola uliginosa, and specimens were visualized using indirect epifluorescence microscopy. The antibodies against cyclotides were specific against selected bracelet cyclotides with high similarity (cyO2, cyO3, cyO8, cyO13) and suitable for immunohistochemistry. The tissue distribution of the cyclotides visualized in this way is consistent with their proposed role in host defense-relatively large quantities were observed in the leaf and petiole epidermis in both Viola species. Cyclotides were also found in vascular tissue in all the assessed plant organs. The vacuole storage of cyclotides was directly shown.

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  • 308.
    Smeets, Cleo J. L. M.
    et al.
    Univ Groningen, Univ Med Ctr Groningen, Dept Genet, Groningen, Netherlands..
    Zmorzynska, Justyna
    Univ Groningen, Univ Med Ctr Groningen, Dept Genet, Groningen, Netherlands..
    Melo, Manuel N.
    Univ Groningen, Groningen Biomol Sci & Biotechnol Inst, Ctr Life Sci, Groningen, Netherlands..
    Stargardt, Anita
    Acad Med Ctr, Dept Cell Biol & Histol, Amsterdam, Netherlands..
    Dooley, Colette
    Torrey Pines Inst Mol Studies, Port St Lucie, FL USA..
    Bakalkin, Georgy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    McLaughlin, Jay
    Univ Florida, Dept Pharmacodynam, Gainesville, FL 32610 USA..
    Sinke, Richard J.
    Univ Groningen, Univ Med Ctr Groningen, Dept Genet, Groningen, Netherlands..
    Marrink, Siewert-Jan
    Reits, Eric
    Acad Med Ctr, Dept Cell Biol & Histol, Amsterdam, Netherlands..
    Verbeek, Dineke S.
    Univ Groningen, Univ Med Ctr Groningen, Dept Genet, Groningen, Netherlands..
    Altered secondary structure of Dynorphin A associates with loss of opioid signalling and NMDA-mediated excitotoxicity in SCA232016In: Human Molecular Genetics, ISSN 0964-6906, E-ISSN 1460-2083, Vol. 25, no 13, p. 2728-2737Article in journal (Refereed)
    Abstract [en]

    Spinocerebellar ataxia type 23 (SCA23) is caused by missense mutations in prodynorphin, encoding the precursor protein for the opioid neuropeptides alpha-neoendorphin, Dynorphin (Dyn) A and Dyn B, leading to neurotoxic elevated mutant Dyn A levels. Dyn A acts on opioid receptors to reduce pain in the spinal cord, but its cerebellar function remains largely unknown. Increased concentration of or prolonged exposure to Dyn A is neurotoxic and these deleterious effects are very likely caused by an N-methyl-D-aspartate-mediated non-opioidmechanism as Dyn A peptides were shown to bind NMDA receptors and potentiate their glutamate-evoked currents. In the present study, we investigated the cellular mechanisms underlying SCA23-mutant Dyn A neurotoxicity. We show that SCA23 mutations in the Dyn A-coding region disrupted peptide secondary structure leading to a loss of the N-terminal alpha-helix associated with decreased kappa-opioid receptor affinity. Additionally, the altered secondary structure led to increased peptide stability of R6W and R9C Dyn A, as these peptides showed marked degradation resistance, which coincided with decreased peptide solubility. Notably, L5S Dyn A displayed increased degradation and no aggregation. R6W and wt Dyn A peptides were most toxic to primary cerebellar neurons. For R6W Dyn A, this is likely because of a switch from opioid to NMDA-receptor signalling, while for wt Dyn A, this switch was not observed. We propose that the pathology of SCA23 results from converging mechanisms of loss of opioid-mediated neuroprotection and NMDA-mediated excitotoxicity.

  • 309. Smith, M.
    et al.
    Martin, J.
    Smith, D.
    Maag, H.
    Naiera, I.
    Jiang, W. R.
    Klumpp, K.
    Leveque, V.
    Cammack, N.
    Johansson, N. G.
    Kalayanov, G.
    Belfrage, A. K.
    Benkestock, K.
    Farnell, K.
    Hiscock, S.
    Lindborg, B.
    Maltseva, T.
    Morisson, V.
    Pinho, P.
    Sund, C.
    Tozer, M.
    Winquist, A.
    Zhou, X. X.
    MEDI 236-Synthesis and anti-HCV activity of 4'-substituted nucleosides2006In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 232Article in journal (Refereed)
  • 310.
    Sooriyaarachchi, Sanjeewani
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structure and Molecular Biology.
    Chofor, Rene
    Univ Ghent, Lab Med Chem FFW, Ottergemsesteenweg 460, B-9000 Ghent, Belgium..
    Risseeuw, Martijn D. P.
    Univ Ghent, Lab Med Chem FFW, Ottergemsesteenweg 460, B-9000 Ghent, Belgium..
    Bergfors, Terese
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structure and Molecular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Pouyez, Jenny
    Univ Namur, Dept Chem, Rue Bruxelles 61, B-5000 Namur, Belgium..
    Dowd, Cynthia S.
    George Washington Univ, Dept Chem, Washington, DC 20052 USA..
    Maes, Louis
    Univ Antwerp, LMPH, Univ Pl 1, B-2610 Antwerp, Belgium..
    Wouters, Johan
    Univ Namur, Dept Chem, Rue Bruxelles 61, B-5000 Namur, Belgium..
    Jones, T. Alwyn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structure and Molecular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Van Calenbergh, Serge
    Univ Ghent, Lab Med Chem FFW, Ottergemsesteenweg 460, B-9000 Ghent, Belgium..
    Mowbray, Sherry L.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structure and Molecular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Targeting an Aromatic Hotspot in Plasmodium falciparum 1-Deoxy-d-xylulose-5-phosphate Reductoisomerase with -Arylpropyl Analogues of Fosmidomycin2016In: ChemMedChem, ISSN 1860-7179, E-ISSN 1860-7187, Vol. 11, no 18, p. 2024-2036Article in journal (Refereed)
    Abstract [en]

    Blocking the 2-C-methyl-d-erythrithol-4-phosphate pathway for isoprenoid biosynthesis offers new ways to inhibit the growth of Plasmodium spp. Fosmidomycin [(3-(N-hydroxyformamido)propyl)phosphonic acid, 1] and its acetyl homologue FR-900098 [(3-(N-hydroxyacetamido)propyl)phosphonic acid, 2] potently inhibit 1-deoxy-d-xylulose-5-phosphate reductoisomerase (Dxr), a key enzyme in this biosynthetic pathway. Arylpropyl substituents were introduced at the -position of the hydroxamate analogue of 2 to study changes in lipophilicity, as well as electronic and steric properties. The potency of several new compounds on the P.falciparum enzyme approaches that of 1 and 2. Activities against the enzyme and parasite correlate well, supporting the mode of action. Seven X-ray structures show that all of the new arylpropyl substituents displace a key tryptophan residue of the active-site flap, which had made favorable interactions with 1 and 2. Plasticity of the flap allows substituents to be accommodated in many ways; in most cases, the flap is largely disordered. Compounds can be separated into two classes based on whether the substituent on the aromatic ring is at the meta or para position. Generally, meta-substituted compounds are better inhibitors, and in both classes, smaller size is linked to better potency.

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  • 311.
    Stevens, Marc Y.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Chow, Shiao Y.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Estrada, Sergio
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Asplund, Veronika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Mitran, Bogdan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Antoni, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Larhed, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Åberg, Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Odell, Luke R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Synthesis of C-11-labeled Sulfonyl Carbamates through a Multicomponent Reaction Employing Sulfonyl Azides, Alcohols, and [C-11]CO2016In: ChemistryOpen, ISSN 2191-1363, Vol. 5, no 6, p. 566-573Article in journal (Refereed)
    Abstract [en]

    We describe the development of a new methodology focusing on C-11-labeling of sulfonyl carbamates in a multicomponent reaction comprised of a sulfonyl azide, an alkyl alcohol, and [C-11] CO. A number of C-11-labeled sulfonyl carbamates were synthesized and isolated, and the developed methodology was then applied in the preparation of a biologically active molecule. The target compound was obtained in 24 +/- 10% isolated radiochemical yield and was evaluated for binding properties in a tumor cell assay; in vivo biodistribution and imaging studies were also performed. This represents the first successful radiolabeling of a non-peptide angiotensin II receptor subtype 2 agonist, C21, currently in clinical trials for the treatment of idiopathic pulmonary fibrosis.

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  • 312.
    Stevens, Marc Y.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Sawant, Rajiv T.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Odell, Luke R.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Synthesis of arylsulfonyl azides via diazotransfer using an imidazole-1-sulfonyl azide salt: Scope and N-15 NMR labeling experiments2014In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Article in journal (Other academic)
  • 313. Stroem, Peter
    et al.
    Malmquist, Jonas
    Hansson, Jonas
    Yngve, Ulrika
    Claesson, Alf.
    Tritium labeling of a class of spirooxazaindolamines possessing analgesic properties.2004In: Synth. Appl. Isot. Labelled Compd., Proc. Int. Symp., 8th, 2004, p. 285-288Conference paper (Refereed)
    Abstract [en]

    In order to study the mol. action of a class of spirooxazaindolamines with promising analgesic activity, tritiated material was prepd. Efficient synthesis of 3H-labeled material allowed essential information on the mol. mechanism for this class of compds. to be obtained. Different approaches for the introduction of the 3H-label on the spirooxazaindole skeleton via 3H-methyliodide were evaluated involving lithium-mediated coupling, zinc-mediated coupling and Stille coupling. Tritiation using 3H2 (g) with a Pd-catalyst was also tested. [on SciFinder(R)]

  • 314.
    Strömstedt, Adam A.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Felth, Jenny
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Bohlin, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Bioassays in Natural Product Research: Strategies and Methods in the Search for Anti-inflammatory and Antimicrobial Activity2014In: Phytochemical Analysis, ISSN 0958-0344, E-ISSN 1099-1565, Vol. 25, no 1, p. 13-28Article, review/survey (Refereed)
    Abstract [en]

    Introduction: Identifying bioactive molecules from complex biomasses requires careful selection and execution of relevant bioassays in the various stages of the discovery process of potential leads and targets.

    Objective: The aim of this review is to share our long-term experience in bioassay-guided isolation, and mechanistic studies, of bioactive compounds from different organisms in nature with emphasis on anti-inflammatory and antimicrobial activity.

    Methods: In the search for anti-inflammatory activity, in vivo and in vitro model combinations with enzymes and cells involved in the inflammatory process have been used, such as cyclooxygenases, human neutrophils and human cancer cell lines. Methods concerning adsorption and perforation of bacteria, fungi, human cells and model membranes, have been developed and optimised, with emphasis on antimicrobial peptides and their interaction with the membrane target, in particular their ability to distinguish host from pathogen.

    Results: A long-term research has provided experience of selection and combination of bioassay models, which has led to an increased understanding of ethnopharmacological and ecological observations, together with in-depth knowledge of mode of action of isolated compounds.

    Conclusion: A more multidisciplinary approach and a higher degree of fundamental research in development of bioassays are often necessary to identify and to fully understand the mode of action of bioactive molecules with novel structure-activity relationships from natural sources. 

    Selection and execution of relevant bioassays are critical in the various stages of the discovery process of potential drug leads and targets from natural sources. The aim of this review is to share our long-term experience in bioassay-guided isolation of bioactive compounds from different organisms in nature with emphasis on anti-inflammatory and antimicrobial activity. We conclude that an increased multidisciplinary approach and a higher degree of fundamental research in development of bioassays are essential to discover complex structure-activity relationships.

  • 315.
    Strömstedt, Adam A.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Kristiansen, Per Eugen
    Univ Oslo, Dept Mol Biosci, Box 1041, N-0316 Oslo, Norway.
    Gunasekera, Sunithi
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Grob, Nathalie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Skjeldal, Lars
    Norwegian Univ Life Sci, Dept Chem Biochem & Food Sci, N-1432 As, Norway.
    Göransson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Selective membrane disruption by the cyclotide kalata B7: complex ions and essential functional groups in the phosphatidylethanolamine binding pocket2016In: Biochimica et Biophysica Acta, ISSN 0006-3002, E-ISSN 1878-2434, Vol. 1858, no 6, p. 1317-1327Article in journal (Refereed)
    Abstract [en]

    The cyclic cystine knot plant peptides called cyclotides are active against a wide variety of organisms. This is primarily achieved through membrane binding and disruption, in part deriving from a high affinity for phosphatidylethanolamine (PE) lipids. Some cyclotides, such as kalata B7 (kB7), form complexes with divalent cations in a pocket associated with the tyrosine residue at position 15 (Tyr15). In the current work we explore the effect of cations on membrane leakage caused by cyclotides kB1, kB2 and kB7, and we identify a functional group that is essential for PE selectivity. The presence of PE-lipids in liposomes increased the membrane permeabilizing potency of the cyclotides, with the potency of kB7 increasing by as much as 740-fold. The divalent cations Mn(2+), Mg(2+) and Ca(2+) had no apparent effect on PE selectivity. However, amino acid substitutions in kB7 proved that Tyr15 is crucial for PE-selective membrane permeabilization on various liposome systems. Although the tertiary structure of kB7 was maintained, as reflected by the NMR solution structure, mutating Tyr into Ser at position 15 resulted in substantially reduced PE selectivity. Ala substitution at the same position produced a similar reduction in PE selectivity, while substitution with Phe maintained high selectivity. We conclude that the phenyl ring in Tyr15 is critical for the high PE selectivity of kB7. Our results suggest that PE-binding and divalent cation coordination occur in the same pocket without adverse effects of competitive binding for the phospholipid.

  • 316.
    Strömstedt, Adam A.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi.
    Vikeved, Elisabet
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi.
    Cárdenas, Paco
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi.
    Alsmark, Cecilia
    Uppsala University.
    Chen, Yung Hsuan
    National Museum of Marine Biology and Aquarium.
    Backlund, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi.
    Aaptamines from Haliclona and bromopyrroles from Agelas — marine sponge alkaloids with distinct modes of action against bacteria and protozoaManuscript (preprint) (Other academic)
  • 317.
    Stubberud, Karin
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Medicinal Chemistry, Analytical Pharmaceutical Chemistry.
    Studies of Micellar Electrokinetic Chromatography as an Analytical Technique in Pharmaceutical Analysis - an Industrial Perspective2002Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Studies have been performed to evaluate the use of micellar electrokinetic chromatography (MEKC), one mode of capillary electrophoresis (CE), as an analytical technique in industrial pharmaceutical analysis. The potential for using chemometrics for the optimisation of MEKC methods has also been studied as well as the possibilities of coupling MEKC with mass spectrometry (MS).

    Two methods were developed, one for the determination of ibuprofen and codeine and another for pilocarpine, together with their degradation products and impurities in both cases. MEKC was found to be the most suitable mode of CE for the methods. Both methods were optimised by means of experimental design. Valuable information was gathered and optimum conditions were defined which resulted in fast systems with baseline-separated peaks. The ibuprofen-codeine method was validated according to the recommended validation procedures of the International Conference of Harmonisation. The validation was performed on a commercially available tablet formulation to verify the suitability of the method, i.e. for quantification of the two main compounds and to determine the degradation products and impurities in area% of each main peak. The following parameters were determined: selectivity, linearity, accuracy, precision, detection limit, quantitation limit, robustness and range. The results confirm that the method is highly suitable for its intended purpose, i.e. as a routine method for assay and impurity determination. The MEKC method for ibuprofen-codeine was coupled to a mass spectrometer in order to evaluate the potential of partial filling (PF)-MEKC-MS for identification of impurities in pharmaceutical substances and products. The so-called partial-filling technique was used to prevent the non-volatile micelles from entering the MS and was shown to fulfil its purpose of providing detection limits of about 10 pg.

    The study clearly shows that micellar electrokinetic chromatography is well-suited as an analytical technique in industrial pharmaceutical analysis.

    List of papers
    1. Fractional Factorial Design Optimization of the Separation of Pilocarpine and its Degradation Products by Capillary Electrophoresis
    Open this publication in new window or tab >>Fractional Factorial Design Optimization of the Separation of Pilocarpine and its Degradation Products by Capillary Electrophoresis
    1997 (English)In: Journal of Chromatography B: Biomedical Sciences and Applications, ISSN 1387-2273, E-ISSN 1878-5603, Vol. 697, no 1-2, p. 207-215Article in journal (Refereed) Published
    Abstract [en]

    The separation of pilocarpine and its degradation products by micellar electrokinetic capillary chromatography (MECC) has been optimized by using fractional factorial design of the experiments. Critical parameters were identified in a screening design, and an optimization design was used to optimize the separation. The optimal separation method was based on a borate buffer with sodium dodecyl sulfate (SDS). It is concluded that by using fractional factorial design it is possible to improve the separation of pilocarpine, its trans epimer, isopilocarpine and their hydrolysis products, pilocarpic acid and isopilocarpic acid.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-89801 (URN)10.1016/S0378-4347(97)00108-4 (DOI)9342671 (PubMedID)
    Available from: 2002-04-15 Created: 2002-04-15 Last updated: 2017-12-14Bibliographically approved
    2. Separation of Ibuprofen, Codeine Phosphate, their Degradation Products and Impurities by Capillary Electrophoresis: I. Method Development and Optimization with Fractional factorial Design
    Open this publication in new window or tab >>Separation of Ibuprofen, Codeine Phosphate, their Degradation Products and Impurities by Capillary Electrophoresis: I. Method Development and Optimization with Fractional factorial Design
    1998 (English)In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 798, no 1-2, p. 307-314Article in journal (Refereed) Published
    Abstract [en]

    A capillary electrophoresis method has been developed and optimized for the separation of ibuprofen, codeine phosphate and their main degradation products and impurities. In the course of developing the method, it was found that micellar electrokinetic capillary chromatography was necessary for the separation of the eleven peaks. A fractional factorial design was used for the optimization of the experiments. Six process parameters were varied at two levels: the concentration of sodium dodecyl sulfate (SDS), the pH, the concentration of acetonitrile, the concentration of boric acid, the field strength and the temperature. All these factors had a significant effect on the migration time and resolution. The optimum conditions were found to be a borate buffer of 40 mM H3BO3 at pH 10 with the addition of 40 mM SDS and 9% acetonitrile, a field strength of 515 V/cm and a temperature of 25 degrees C. This resulted in baseline separation of the eleven peaks within 12 min.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-89802 (URN)10.1016/S0021-9673(97)00955-2 (DOI)9542142 (PubMedID)
    Available from: 2002-04-15 Created: 2002-04-15 Last updated: 2017-12-14Bibliographically approved
    3. Separation of Ibuprofen, Codeine Phosphate, their Degradation Products and Impurities by Capillary Electrophoresis: II. Validation
    Open this publication in new window or tab >>Separation of Ibuprofen, Codeine Phosphate, their Degradation Products and Impurities by Capillary Electrophoresis: II. Validation
    1998 (English)In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 826, no 1, p. 95-102Article in journal (Refereed) Published
    Abstract [en]

    A micellar electrokinetic chromatography method for the determination of ibuprofen and codeine phosphate hemihydrate and their degradation products and impurities in a commercial tablet formulation has been validated. The validation has been performed according to the International Conference of Harmonisation's guidance on the validation of analytical methods, and selectivity, linearity, accuracy, precision, detection limit, quantitation limit, robustness and range test were performed to determine the suitability of the method. It was possible to use the fractional factorial design model from the optimisation of the method to draw conclusions about its robustness. The results confirm that the method is highly suitable for its intended purpose.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-89803 (URN)10.1016/S0021-9673(98)00711-0 (DOI)9882139 (PubMedID)
    Available from: 2002-04-15 Created: 2002-04-15 Last updated: 2017-12-14Bibliographically approved
    4. Partial filling micellar electrokinetic chromatography optimisation studies of ibuprofen, codeine and degradation products, and coupling to mass spectrometry: Part I
    Open this publication in new window or tab >>Partial filling micellar electrokinetic chromatography optimisation studies of ibuprofen, codeine and degradation products, and coupling to mass spectrometry: Part I
    2002 (English)In: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 23, no 4, p. 572-577Article in journal (Refereed) Published
    Abstract [en]

    Studies have been performed to evaluate whether an on-line partial filling-micellar electrokinetic chromatography (PF-MEKC) system could be applied to a recently developed MEKC method for the separation of ibuprofen, codeine and one of the degradation products. Attempts to couple the PF-MEKC system to MS have also been performed. SDS concentration, micellar zone length and concentration of acetonitrile in the buffer were optimized using factorial design. When a small micelle zone was injected directly after the sample introduction, the results improved markedly. The MS parameters have not been optimized, but the studies show promising results for the use of PF-MEKC-mass spectrometry for identification of the degradation products.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-89804 (URN)10.1002/1522-2683(200202)23:4<572::AID-ELPS572>3.0.CO;2-# (DOI)11870767 (PubMedID)
    Available from: 2002-04-15 Created: 2002-04-15 Last updated: 2017-12-14Bibliographically approved
    5. Partial filling micellar electrokinetic chromatography optimisation studies of ibuprofen, codeine and degradation products, and coupling to mass spectrometry: Part II
    Open this publication in new window or tab >>Partial filling micellar electrokinetic chromatography optimisation studies of ibuprofen, codeine and degradation products, and coupling to mass spectrometry: Part II
    2003 (English)In: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 24, no 6, p. 1008-1015Article in journal (Refereed) Published
    Abstract [en]

    We describe the use of partial filling-micellar electrokinetic chromatography-mass spectrometry (PF-MEKC-MS) on the pharmaceutical ingredients ibuprofen and codeine phosphate as well as their degradation products and impurities. The study focuses on the change of the borate buffer to the volatile ammonium acetate and the optimization of critical MS parameters. The sensitivity of the method is also evaluated. The results are compared to an existing MEKC-UV method that is used for quantitative determination of the two main substances as well as for the analysis of the degradation products. It is concluded that the PF-MEKC-MS system is suitable for separation and identification.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-89805 (URN)10.1002/elps.200390116 (DOI)12658689 (PubMedID)
    Available from: 2002-04-15 Created: 2002-04-15 Last updated: 2017-12-14Bibliographically approved
    Download full text (pdf)
    FULLTEXT01
  • 318.
    Sundell, Gustav
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Vögeli, Beat
    Department of Biochemistry and Molecular Genetics, University of Colorado at Denver, 12801 East 17th Avenue, Aurora, Colorado 80045, United States.
    Ivarsson, Ylva
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Chi, Celestine N.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    The Sign of Nuclear Magnetic Resonance Chemical Shift Difference as a Determinant of the Origin of Binding Selectivity: Elucidation of the Position Dependence of Phosphorylation in Ligands Binding to Scribble PDZ12018In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 57, no 1, p. 66-71Article in journal (Refereed)
    Abstract [en]

    The use of nuclear magnetic resonance chemical shift perturbation to monitor changes taking place around the binding site of a ligand-protein interaction is a routine and widely applied methodology in the field of protein biochemistry. Shifts are often acquired by titrating various concentrations of ligand to a fixed concentration of the receptor and may serve the purpose, among others, of determining affinity constants, locating binding surfaces, or differentiating between binding mechanisms. Shifts are quantified by the so-called combined chemical shift difference. Although the directionality of shift changes is often used for detailed analysis of specific cases, the approach has not been adapted in standard chemical shift monitoring. This is surprising as it would not require additional effort. Here, we demonstrate the importance of the sign of the chemical shift difference induced by ligand-protein interaction. We analyze the sign of the 15N/1H shift changes of the PDZ1 domain of Scribble upon interaction with two pairs of phosphorylated and unphosphorylated peptides. We find that detailed differences in the molecular basis of this PDZ-ligand interaction can be obtained from our analysis to which the classical method of combined chemical shift perturbation analysis is insensitive. In addition, we find a correlation between affinity and millisecond motions. Application of the methodology to Cyclophilin a, a cis-trans isomerase, reveals molecular details of peptide recognition. We consider our directionality vector chemical shift analysis as a method of choice when distinguishing the molecular origin of binding specificities of a class of similar ligands, which is often done in drug discovery.

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  • 319.
    Sundelöf, Lars-Olof
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    AIR AND FIRE Carl Wilhelm Scheele, Torbern Bergman, The Royal Society of Sciences and the Discovery of Oxygen in Uppsala in the year 17722009In: OXYGEN TRANSPORT TO TISSUE XXX, 2009, p. 1-6Conference paper (Refereed)
  • 320.
    Sundström, Ingela
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Arts, Joris
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Westerlund, Douglas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Analytical Pharmaceutical Chemistry.
    Andrén, Per E.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    In vivo investigation of brain and systemic ketobemidone metabolism2010In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 135, no 2, p. 405-413Article in journal (Refereed)
    Abstract [en]

    Ketobemidone metabolites have previously been identified in urine and plasma; here we show, for the first time, that norketobemidone and ketobemidone N-oxide are present in in vivo microdialysate from rat brain (striatum) after reverse microdialysis, suggesting striatal metabolism of ketobemidone. Ketobemidone metabolites were also identified in in vivo microdialysate samples from brain and blood, as well as in urine from rats, after subcutaneous administration of ketobemidone. Three Phase I metabolites (norketobemidone, ketobemidone N-oxide and hydroxymethoxyketobemidone) and three Phase II metabolites (glucuronic acid conjugates of ketobemidone, norketobemidone and hydroxymethoxyketobemidone) were identified in the microdialysates after subcutaneous administration. Coupled capillary liquid chromatography tandem mass spectrometry (LC-MS/MS) and SPE (boronate)-MS/MS were utilized for the analysis of the biological samples. The Phase I metabolites were identified by comparing the retention times and tandem mass spectra of the microdialysates with synthetic standards. The Phase II metabolites were identified by determination of exact masses and by comparing the tandem mass spectra of the microdialysates with those of synthetic standards for the aglycones. Hydroxyketobemidone, a catechol-type Phase I metabolite, was selectively isolated by solid-phase boronate-complexation but identified in urine alone. This work demonstrated that the in vivo microdialysis technique in combination with LC-MS/MS can be used to study the local metabolism of a drug in the brain.

  • 321.
    Svahn, K. Stefan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Goransson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Strömstedt, Adam A.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    El-Seedi, Hesham
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Bohlin, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Larsson, D. G. J.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Olsen, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Chryssanthou, E.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    The search for new antibiotic substances from filamentous fungi2012In: Planta Medica, ISSN 0032-0943, E-ISSN 1439-0221, Vol. 78, no 11, p. 1162-1162Article in journal (Other academic)
  • 322.
    Svahn, Stefan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Analysis of Secondary Metabolites from Aspergillus fumigatus and Penicillium nalgiovense: Antimicrobial Compounds from Filamentous Fungi Isolated from Extreme Environments2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis describes the cultivation and extraction of filamentous fungi isolated from extreme environments in the search for new antibiotic compounds. Filamentous fungi are a rich source of medicines including antibiotics, and it is believed that many currently unknown fungal species and bioactive fungal metabolites remain to be discovered.

    Aspergillus fumigatus and Penicillium nalgiovense strains were isolated from an antibiotic-contaminated riverbed near Hyderabad, India, and soil taken from a penguin’s nest on Paulete Island, Antarctica, respectively. It was anticipated that the extreme conditions within these environments would exert unusual selective pressures on their filamentous fungi, possibly causing the secretion of new bioactive compounds.

    The cultivation, extraction and analysis of metabolites from the A. fumigatus strain resulted in the isolation of the antimicrobial substance gliotoxin. Subsequent investigations revealed that this strain’s secretion of gliotoxin was increased by as much as 65 % when it was cultivated in the presence of pathogen-associated molecular patterns. These results indicate the existence of a fungal receptor/signaling system for detecting nearby bacteria. The scope for using gliotoxin and the related metabolite bis(methyl)gliotoxin as biomarker metabolites for diagnosing the lethal pulmonary condition invasive aspergillosis was also investigated. Bronchoalveolar lavage fluid from 42 patients with and without possible invasive aspergillosis was extracted and analyzed. The results obtained suggest that gliotoxin and bis(methyl)gliotoxin are not suitable markers for diagnosing invasive aspergillosis.

    Studies on the P. nalgiovense strain from Antarctica resulted in the isolation of the antifungal agent amphotericin B. The secretion of this compound increased when P. nalgiovense was cultured on a potato-dextrose agar enriched with coconut flakes rather than liquid RPMI 1640 medium. This was the first time amphotericin B was isolated from any organism other than the bacterium Streptomyces nodosus.

    The results presented in this thesis will be useful in the continuing search for novel bioactive compounds, the diagnosis of fungal infections, and as a source of insight into the interactions between microorganisms. Moreover, they show that even extensively studied fungal genera such as Aspergillus and Penicillium are not completely understood and may produce unexpected or previously unknown bioactive metabolites under appropriate conditions.

    List of papers
    1. Antimicrobial activity of filamentous fungi isolated from highly antibiotic-contaminated river sediment
    Open this publication in new window or tab >>Antimicrobial activity of filamentous fungi isolated from highly antibiotic-contaminated river sediment
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    2012 (English)In: Infection ecology & epidemiology, ISSN 2000-8686, Vol. 2, p. 11591-Article in journal (Refereed) Published
    Abstract [en]

    Background:

    Filamentous fungi are well known for their production of substances with antimicrobial activities, several of which have formed the basis for the development of new clinically important antimicrobial agents. Recently, environments polluted with extraordinarily high levels of antibiotics have been documented, leading to strong selection pressure on local sentinel bacterial communities. In such microbial ecosystems, where multidrug-resistant bacteria are likely to thrive, it is possible that certain fungal antibiotics have become less efficient, thus encouraging alternative strategies for fungi to compete with bacteria.

    Methods:

    In this study, sediment of a highly antibiotic-contaminated Indian river was sampled in order to investigate the presence of cultivable filamentous fungi and their ability to produce substances with antimicrobial activity.

    Results:

    Sixty one strains of filamentous fungi, predominantly various Aspergillus spp. were identified. The majority of the Aspergillus strains displayed antimicrobial activity against methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Escherichia coli, vancomycin-resistant Enterococcus faecalis and Candida albicans. Bioassay-guided isolation of the secondary metabolites of A. fumigatus led to the identification of gliotoxin.

    Conclusion:

    This study demonstrated proof of principle of using bioassay-guided isolation for finding bioactive molecules

    Keywords
    secondary metabolites, Aspergillus, gliotoxin
    National Category
    Microbiology
    Research subject
    Pharmacognosy
    Identifiers
    urn:nbn:se:uu:diva-188192 (URN)10.3402/iee.v2i0.11591 (DOI)
    Funder
    Vinnova
    Available from: 2012-12-13 Created: 2012-12-13 Last updated: 2015-03-11Bibliographically approved
    2. Penicillium nalgiovense Laxa isolated from Antarctica is a new source of the antifungal metabolite amphotericin B
    Open this publication in new window or tab >>Penicillium nalgiovense Laxa isolated from Antarctica is a new source of the antifungal metabolite amphotericin B
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    2015 (English)In: Fungal biology and biothechnology, Vol. 2, no 1Article in journal (Refereed) Published
    Abstract [en]

    Background: The need for new antibiotic drugs increases as pathogenic microorganisms continue to develop resistance against current antibiotics. We obtained samples from Antarctica as part of a search for new antimicrobial metabolites derived from filamentous fungi. This terrestrial environment in the South Pole is hostile and extreme due to a sparsely populated food web, low temperatures, and insufficient liquid water availability. We hypothesize that this environment could cause the development of fungal defense or survival mechanisms not found elsewhere.

    Results: We isolated a strain of Penicillium nalgiovense Laxa from a soil sample obtained from an abandoned penguin’s nest. Amphotericin B was the only metabolite secreted from P. nalgiovense Laxa with noticeable antimicrobial activity,with minimum inhibitory concentration of 0.125 µg/mL against Candida albicans. This is the first time that amphotericin B has been isolated from an organism other than the bacterium Streptomyces nodosus. In terms of amphotericin B production, cultures on solid medium proved to be a more reliable and favorable choice compared to a liquid.

    Conclusions: These results encourage further investigation of the many unexplored sampling sites characterized by extreme conditions, and confirm filamentous fungi as potential sources of metabolites with antimicrobial activity.

    Keywords
    Amphotericin B, Penicillium nalgiovense Laxa, Antarctica
    National Category
    Medicinal Chemistry
    Research subject
    Pharmacognosy
    Identifiers
    urn:nbn:se:uu:diva-242609 (URN)10.1186/s40694-014-0011-x (DOI)
    Available from: 2015-01-28 Created: 2015-01-28 Last updated: 2018-01-11Bibliographically approved
    3. Induction of Gliotoxin Secretion in Aspergillus fumigatus by Bacteria-Associated Molecules
    Open this publication in new window or tab >>Induction of Gliotoxin Secretion in Aspergillus fumigatus by Bacteria-Associated Molecules
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    2014 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 4, p. e93685-Article in journal (Refereed) Published
    Abstract [en]

    Aspergillus fumigatus is the most common causative agent of mold diseases in humans, giving rise to life-threatening infections in immunocompromised individuals. One of its secreted metabolites is gliotoxin, a toxic antimicrobial agent. The aim of this study was to determine whether the presence of pathogen-associated molecular patterns in broth cultures of A. fumigatus could induce gliotoxin production. Gliotoxin levels were analyzed by ultra-performance liquid chromatography and mass spectrometry. The presence of a bacteria-derived lipopolysaccharide, peptidoglycan, or lipoteichoic acid in the growth media at a concentration of 5 mu g/ml increased the gliotoxin concentration in the media by 37%, 65%, and 35%, respectively. The findings reveal a correlation between the concentrations of pathogen-associated molecular patterns and gliotoxin secretion. This shows that there is a yet uncharacterized detection system for such compounds within fungi. Inducing secondary metabolite production by such means in fungi is potentially relevant for drug discovery research. Our results also give a possible explanation for the increased virulence of A. fumigatus during bacterial co-infection, one that is important for the transition from colonization to invasiveness in this pulmonary disease.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-224740 (URN)10.1371/journal.pone.0093685 (DOI)000334107500056 ()
    Available from: 2014-05-21 Created: 2014-05-19 Last updated: 2017-12-05Bibliographically approved
    4. Bis(methyl)gliotoxin and gliotoxin in bronchoalveolar lavage fluids are not suitable markers for invasive aspergillosis
    Open this publication in new window or tab >>Bis(methyl)gliotoxin and gliotoxin in bronchoalveolar lavage fluids are not suitable markers for invasive aspergillosis
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Introduction: Invasive aspergillosis is challenging to diagnose partly due to shortcomings in sensitivity, reliability, and selectivity of current diagnostic methods, which rely on cultures, assays, and histopathology. This problem may be addressed by chemical analysis of metabolites in lung fluid from infected patients. Gliotoxin and bis(methyl)gliotoxin have been pinpointed as potential marker metabolites in serum and plasma for invasive aspergillosis patients, but whether lung fluid samples could be assessed for these markers is still unknown.

    Methods: Bronchoalveolar lavage samples were taken from 42 individuals with a variety of pulmonary diseases whereof  20 were diagnosed with possible invasive aspergillosis. The samples were analyzed with ultra high performance liquid chromatography coupled to triple quadropole time-of-flight mass spectrometry to investigate the use of the Aspergillus fumigatus metabolites gliotoxin and bis(methyl)gliotoxin as marker metabolites for invasive aspergillosis.

    Results: Gliotoxin was not detected in any of the 42 samples, but  bis(methyl)gliotoxin in 10 (24%). Bis(methyl)gliotoxin was detected in 5 (25%) of the 20 patients with possible IA and in 5 (23%) in the other 22 samples. One unknown compound (357.30 m/z) with a similar mass spectrum profile to bis(methyl)gliotoxin (357.09 m/z) was found in 32 (76%) of all samples.

    Conclusions: Neither gliotoxin nor bis(methyl)gliotoxin appears to be an acceptable marker metabolite in bronchoalveolar lavage fluids for invasive aspergillosis. Further development of MS-based analyses should include chromatography. 

    Keywords
    Invasive aspergillosis, gliotoxin, bis(methyl)gliotoxin, Aspergillus fumigatus, diagnosis
    National Category
    Medicinal Chemistry
    Research subject
    Pharmacognosy
    Identifiers
    urn:nbn:se:uu:diva-242610 (URN)
    Available from: 2015-01-28 Created: 2015-01-28 Last updated: 2018-01-11Bibliographically approved
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  • 323.
    Svahn, Stefan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy. Uppsala Universitet.
    Chryssanthou, Erja
    Olsen, Björn
    Bohlin, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Göransson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Penicillium nalgiovense Laxa isolated from Antarctica is a new source of the antifungal metabolite amphotericin B2015In: Fungal biology and biothechnology, Vol. 2, no 1Article in journal (Refereed)
    Abstract [en]

    Background: The need for new antibiotic drugs increases as pathogenic microorganisms continue to develop resistance against current antibiotics. We obtained samples from Antarctica as part of a search for new antimicrobial metabolites derived from filamentous fungi. This terrestrial environment in the South Pole is hostile and extreme due to a sparsely populated food web, low temperatures, and insufficient liquid water availability. We hypothesize that this environment could cause the development of fungal defense or survival mechanisms not found elsewhere.

    Results: We isolated a strain of Penicillium nalgiovense Laxa from a soil sample obtained from an abandoned penguin’s nest. Amphotericin B was the only metabolite secreted from P. nalgiovense Laxa with noticeable antimicrobial activity,with minimum inhibitory concentration of 0.125 µg/mL against Candida albicans. This is the first time that amphotericin B has been isolated from an organism other than the bacterium Streptomyces nodosus. In terms of amphotericin B production, cultures on solid medium proved to be a more reliable and favorable choice compared to a liquid.

    Conclusions: These results encourage further investigation of the many unexplored sampling sites characterized by extreme conditions, and confirm filamentous fungi as potential sources of metabolites with antimicrobial activity.

    Download full text (pdf)
    fulltext
  • 324.
    Svahn, Stefan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Göransson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Chryssanthou, Erja
    Bohlin, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Janson, Christer
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Respiratory Medicine and Allergology.
    Olsen, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine.
    Bis(methyl)gliotoxin and gliotoxin in bronchoalveolar lavage fluids are not suitable markers for invasive aspergillosisManuscript (preprint) (Other academic)
    Abstract [en]

    Introduction: Invasive aspergillosis is challenging to diagnose partly due to shortcomings in sensitivity, reliability, and selectivity of current diagnostic methods, which rely on cultures, assays, and histopathology. This problem may be addressed by chemical analysis of metabolites in lung fluid from infected patients. Gliotoxin and bis(methyl)gliotoxin have been pinpointed as potential marker metabolites in serum and plasma for invasive aspergillosis patients, but whether lung fluid samples could be assessed for these markers is still unknown.

    Methods: Bronchoalveolar lavage samples were taken from 42 individuals with a variety of pulmonary diseases whereof  20 were diagnosed with possible invasive aspergillosis. The samples were analyzed with ultra high performance liquid chromatography coupled to triple quadropole time-of-flight mass spectrometry to investigate the use of the Aspergillus fumigatus metabolites gliotoxin and bis(methyl)gliotoxin as marker metabolites for invasive aspergillosis.

    Results: Gliotoxin was not detected in any of the 42 samples, but  bis(methyl)gliotoxin in 10 (24%). Bis(methyl)gliotoxin was detected in 5 (25%) of the 20 patients with possible IA and in 5 (23%) in the other 22 samples. One unknown compound (357.30 m/z) with a similar mass spectrum profile to bis(methyl)gliotoxin (357.09 m/z) was found in 32 (76%) of all samples.

    Conclusions: Neither gliotoxin nor bis(methyl)gliotoxin appears to be an acceptable marker metabolite in bronchoalveolar lavage fluids for invasive aspergillosis. Further development of MS-based analyses should include chromatography. 

  • 325.
    Svensson, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Computational Methods in Medicinal Chemistry: Mechanistic Investigations and Virtual Screening Development2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Computational methods have become an integral part of drug development and can help bring new and better drugs to the market faster. The process of predicting the biological activity of large compound collections is known as virtual screening, and has been instrumental in the development of several drugs today in the market. Computational methods can also be used to elucidate the energies associated with chemical reactivity and predict how to improve a synthetic protocol. These two applications of computational medicinal chemistry is the focus of this thesis.

    In the first part of this work, quantum mechanics has been used to probe the energy surface of palladium(II)-catalyzed decarboxylative reactions in order to gain a better understating of these systems (paper I-III). These studies have mapped the reaction pathways and been able to make accurate predictions that were verified experimentally.

    The other focus of this work has been to develop virtual screening methodology. Our first study in the area (paper IV) investigated if the results from several virtual screening methods could be combined using data fusion techniques in order to get a more consistent result and better performance. The study showed that the results obtained from data fusion were more consistent than the results from any single method. The data fusion methods also for several target had a better performance than any of the included single methods.

    Next, we developed a dataset suitable for evaluating the performance of virtual screening methods when applied to large compound collection as a replacement or complement for high throughput screening (paper V). This is the first benchmark dataset of its kind.

    Finally, a method for using computationally derived reaction coordinates as basis for virtual screening was developed. The aim was to find inhibitors that resemble key steps in the mechanism (paper VI). This initial proof of concept study managed to locate several known and one previously not reported reaction mimetics against insulin regulated amino peptidase.

    List of papers
    1. Theoretical and Experimental Investigation of Palladium(II)-Catalyzed Decarboxylative Addition of Arenecarboxylic Acid to Nitrile
    Open this publication in new window or tab >>Theoretical and Experimental Investigation of Palladium(II)-Catalyzed Decarboxylative Addition of Arenecarboxylic Acid to Nitrile
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    2013 (English)In: Organometallics, ISSN 0276-7333, E-ISSN 1520-6041, Vol. 32, no 2, p. 490-497Article in journal (Refereed) Published
    Abstract [en]

    The reaction mechanism of palladium(II)-catalyzed decarboxylative addition of 2,6-dimethoxybenzoic acid to acetonitrile was investigated by means of density functional theory (DFT) calculations. Calculations of the free energy profile for decarboxylation and carbopalladation indicated carbopalladation as the rate-determining step of the reaction. Investigation of the free energy profile for a series of experimentally evaluated nitrogen-based bidentate palladium ligands revealed that higher energy is required for decarboxylation and carbopalladation employing the experimentally least efficient ligand. The DFT investigation also showed that the relative free energies of the transition states were lowered in polar solvent, and preparative experiments confirmed that a nonoptimal ligand could be greatly improved by addition of water to the reaction system.

    National Category
    Medical and Health Sciences Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-196041 (URN)10.1021/om3009525 (DOI)000314332100017 ()
    Available from: 2013-03-04 Created: 2013-03-04 Last updated: 2017-12-06Bibliographically approved
    2. Decarboxylative Palladium(II)-Catalyzed Synthesis of Aryl Amidines from Aryl Carboxylic Acids: Development and Mechanistic Investigation
    Open this publication in new window or tab >>Decarboxylative Palladium(II)-Catalyzed Synthesis of Aryl Amidines from Aryl Carboxylic Acids: Development and Mechanistic Investigation
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    2013 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 19, no 41, p. 13803-13810Article in journal (Refereed) Published
    Abstract [en]

    A fast and convenient synthesis of aryl amidines starting from carboxylic acids and cyanamides is reported. The reaction was achieved by palladium(II)-catalysis in a one-step microwave protocol using [Pd(O2CCF3)(2)], 6-methyl-2,2-bipyridyl and trifluoroacetic acid (TFA) in N-methylpyrrolidinone (NMP), providing the corresponding aryl amidines in moderate to excellent yields. The protocol is very robust with regards to the cyanamide coupling partner but requires electron-rich ortho-substituted aryl carboxylic acids. Mechanistic insight was provided by a DFT investigation and direct ESI-MS studies of the reaction. The results of the DFT study correlated well with the experimental findings and, together with the ESI-MS study, support the suggested mechanism. Furthermore, a scale-out (scale-up) was performed with a non-resonant microwave continuous-flow system, achieving a maximum throughput of 11mmolh(-1) by using a glass reactor with an inner diameter of 3mm at a flow rate of 1mLmin(-1).

    Keywords
    decarboxylation, density functional calculations, mass spectrometry, microwave chemistry, palladium
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-210180 (URN)10.1002/chem.201301809 (DOI)000325135800026 ()
    Available from: 2013-11-04 Created: 2013-11-04 Last updated: 2017-12-06Bibliographically approved
    3. Mechanistic Investigation of Palladium(II)-Catalyzed Decarboxylative Synthesis of Electron Rich Styrenes and 1,1-Diarylethenes
    Open this publication in new window or tab >>Mechanistic Investigation of Palladium(II)-Catalyzed Decarboxylative Synthesis of Electron Rich Styrenes and 1,1-Diarylethenes
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    (English)Manuscript (preprint) (Other academic)
    Keywords
    palladium, DFT, mechanism, styrene
    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-259441 (URN)
    Available from: 2015-08-04 Created: 2015-08-04 Last updated: 2015-10-01
    4. Virtual Screening Data Fusion Using Both Structure- and Ligand-Based Methods
    Open this publication in new window or tab >>Virtual Screening Data Fusion Using Both Structure- and Ligand-Based Methods
    2012 (English)In: Journal of Chemical Information and Modeling, ISSN 1549-9596, Vol. 52, no 1, p. 225-232Article in journal (Refereed) Published
    Abstract [en]

    Virtual screening is widely applied in drug discovery, and significant effort has been put into improving current methods. In this study, we have evaluated the performance of compound ranking in virtual screening using five different data fusion algorithms on a total of 16 data sets. The data were generated by docking, pharmacophore search, shape similarity, and electrostatic similarity, spanning both structure- and ligand-based methods. The algorithms used for data fusion were sum rank, rank vote, sum score, Pareto ranking, and parallel selection. None of the fusion methods require any prior knowledge or input other than the results from the single methods and, thus, are readily applicable. The results show that compound ranking using data fusion improves the performance and consistency of virtual screening compared to the single methods alone. The best performing data fusion algorithm was parallel selection, but both rank voting and Pareto ranking also have good performance.

    National Category
    Medicinal Chemistry
    Identifiers
    urn:nbn:se:uu:diva-169381 (URN)10.1021/ci2004835 (DOI)000299351600021 ()
    Available from: 2012-02-28 Created: 2012-02-28 Last updated: 2018-01-12Bibliographically approved
    5. Toward a Benchmarking Data Set Able to Evaluate Ligand- and Structure-based Virtual Screening Using Public HTS Data
    Open this publication in new window or tab >>Toward a Benchmarking Data Set Able to Evaluate Ligand- and Structure-based Virtual Screening Using Public HTS Data
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    2015 (English)In: Journal of Chemical Information and Modeling, ISSN 1549-9596, Vol. 55, no 2, p. 343-353Article in journal (Refereed) Published
    Abstract [en]

    Virtual screening has the potential to accelerate and reduce costs of probe development and drug discovery. To develop and benchmark virtual screening methods, validation data sets are commonly used. Over the years, such data sets have been constructed to overcome the problems of analogue bias and artificial enrichment. With the rapid growth of public domain databases containing high-throughput screening data, such as the PubChem BioAssay database, there is an increased possibility to use such data for validation. In this study, we identify PubChem data sets suitable for validation of both structure- and ligand-based virtual screening methods. To achieve this, high-throughput screening data for which a crystal structure of the bioassay target was available in the PDB were identified. Thereafter, the data sets were inspected to identify structures and data suitable for use in validation studies. In this work, we present seven data sets (MMP13, DUSP3, PTPN22, EPHX2, CTDSP1, MAPK10, and CDK5) compiled using this method. In the seven data sets, the number of active compounds varies between 19 and 369 and the number of inactive compounds between 59 405 and 337 634. This gives a higher ratio of the number of inactive to active compounds than what is found in most benchmark data sets. We have also evaluated the screening performance using docking and 3D shape similarity with default settings. To characterize the data sets, we used physicochemical similarity and 2D fingerprint searches. We envision that these data sets can be a useful complement to current data sets used for method evaluation.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2015
    National Category
    Structural Biology Pharmaceutical Chemistry
    Research subject
    Chemistry with specialization in Bioorganic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-248018 (URN)10.1021/ci5005465 (DOI)000349943100014 ()25564966 (PubMedID)
    Available from: 2015-03-26 Created: 2015-03-26 Last updated: 2018-03-05Bibliographically approved
    6. Virtual Screening for Transition State Analogue Inhibitors of IRAP Based on Quantum Mechanically Derived Reaction Coordinates
    Open this publication in new window or tab >>Virtual Screening for Transition State Analogue Inhibitors of IRAP Based on Quantum Mechanically Derived Reaction Coordinates
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    2015 (English)In: Journal of Chemical Information and Modeling, ISSN 1549-960X, Vol. 55, no 9, p. 1984-1993Article in journal (Refereed) Published
    Abstract [en]

    Transition state- and high energy intermediate mimetics have the potential to be very potent enzyme inhibitors. In this study a model of peptide hydrolysis in the active site of insulin-regulated aminopeptidase (IRAP) was developed using density functional theory calculations and the cluster approach. The 3D structure models of the reaction coordinates were used for virtual screening to obtain new chemical starting points for IRAP inhibitors. This mechanism-based virtual screening process managed to identify several known peptidase inhibitors from a library of over five million compounds and biological testing identified one compound not previously reported as an IRAP inhibitor. This novel methodology for virtual screening is a promising approach to identify new inhibitors mimicking key transition states or intermediates of an enzymatic reaction.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2015
    National Category
    Medicinal Chemistry
    Identifiers
    urn:nbn:se:uu:diva-259442 (URN)10.1021/acs.jcim.5b00359 (DOI)000362056900018 ()26252078 (PubMedID)
    Funder
    Carl Tryggers foundation Swedish Research Council
    Available from: 2015-08-05 Created: 2015-08-04 Last updated: 2018-01-11Bibliographically approved
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  • 326.
    Svensson, Fredrik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Engen, Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Lundbäck, Thomas
    Karolinska Inst, Dept Med Biochem & Biophys, Div Translat Med & Chem Biol, Chem Biol Consortium Sweden,Sci Life Lab, SE-17165 Solna, Sweden.
    Larhed, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Sköld, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Virtual Screening for Transition State Analogue Inhibitors of IRAP Based on Quantum Mechanically Derived Reaction Coordinates2015In: Journal of Chemical Information and Modeling, ISSN 1549-960X, Vol. 55, no 9, p. 1984-1993Article in journal (Refereed)
    Abstract [en]

    Transition state- and high energy intermediate mimetics have the potential to be very potent enzyme inhibitors. In this study a model of peptide hydrolysis in the active site of insulin-regulated aminopeptidase (IRAP) was developed using density functional theory calculations and the cluster approach. The 3D structure models of the reaction coordinates were used for virtual screening to obtain new chemical starting points for IRAP inhibitors. This mechanism-based virtual screening process managed to identify several known peptidase inhibitors from a library of over five million compounds and biological testing identified one compound not previously reported as an IRAP inhibitor. This novel methodology for virtual screening is a promising approach to identify new inhibitors mimicking key transition states or intermediates of an enzymatic reaction.

  • 327.
    Svensson, Fredrik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Karlén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Sköld, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Virtual Screening Data Fusion Using Both Structure- and Ligand-Based Methods2012In: Journal of Chemical Information and Modeling, ISSN 1549-9596, Vol. 52, no 1, p. 225-232Article in journal (Refereed)
    Abstract [en]

    Virtual screening is widely applied in drug discovery, and significant effort has been put into improving current methods. In this study, we have evaluated the performance of compound ranking in virtual screening using five different data fusion algorithms on a total of 16 data sets. The data were generated by docking, pharmacophore search, shape similarity, and electrostatic similarity, spanning both structure- and ligand-based methods. The algorithms used for data fusion were sum rank, rank vote, sum score, Pareto ranking, and parallel selection. None of the fusion methods require any prior knowledge or input other than the results from the single methods and, thus, are readily applicable. The results show that compound ranking using data fusion improves the performance and consistency of virtual screening compared to the single methods alone. The best performing data fusion algorithm was parallel selection, but both rank voting and Pareto ranking also have good performance.

  • 328.
    Svensson, Lars A.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmaceutical Chemistry.
    Chiral packed capillary chromatography using an in-column immobilized selector: With special emphasis on vancomycin1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Packed fused silica capillary columns have been used for enantioseparation of drugs and related compounds. The technique to prepare the chiral stationary phase (CSP) involved a reductive amination of aldehyde functionalized silica with a chiral selector. The immobilization was performed in the packed column, thereby minimizing the use of selector. An α-chymotrypsin CSP was used to investigate the influence of the pore size on the chromatographic performance. Both selectivity and efficiency were better on a 1000 Å pore size material.

    The retention mechanism of some arylpropionic acids on a vancomycin CSP was studied. A two-site retention model was sufficient to qualitatively describe the effects of different mobile phase compositions, including buffer, modifier and counter ion concentration as well as pH. A closer investigation of the immobilization reaction was also conducted for the vancomycin selector with the aim of elucidating if the linkage to the silica affected the enantioselective retention. To accomplish this one of the two amino groups was temporarily protected while the other was linked to the silica. However, no significant difference in enantioresolution between the two defined CSPs formed was obtained in comparison with the one resulting from the immobilization of native vancomycin.

    Different types of interactions seemed to be important in different modes of chromatography. Reversed phase LC primarily separated acidic compounds while polar organic phase LC (POPLC) was better suited to resolve basic compounds. Supercritical fluid chromatography (SFC) and normal phase LC could separate both acidic and basic as well as neutral compounds, but SFC had superior chromatographic performance resulting in both higher efficiency and selectivity.

    Acid and base interactions between analyte and selector seems to be the key process for chiral discrimination. It has previously been shown that the N-terminal of vancomycin was important for acidic compounds. With the use of an analogous selector, ristocetin A, it is here indicated that the C-terminal is equally important for resolution of bases.

  • 329. Syvänen, Stina
    et al.
    Eriksson, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Genchel, Tove
    Lindhe, Örjan
    Antoni, Gunnar
    Långström, Bengt
    [1-11C]Ethyl iodide and [1-11C]propyl iodide in the synthesis of two potential NK1-receptor ligands and initial PET-imagingManuscript (Other academic)
  • 330.
    Szałaj, Natalia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Lu, Lu
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Structural Biology.
    Benediktsdottir, Andrea
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Zamaratski, Edouard
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Cao, Sha
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Olanders, Gustav
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Hedgecock, Charles
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Karlen, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Erdélyi, Máté
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Organic Chemistry.
    Hughes, Diarmaid
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Mowbray, Sherry L
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Brandt, Peter
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Boronic ester-linked macrocyclic lipopeptides as serine protease inhibitors targeting Escherichia coli type I signal peptidase.2018In: European Journal of Medicinal Chemistry, ISSN 0223-5234, E-ISSN 1768-3254, Vol. 157, p. 1346-1360Article in journal (Refereed)
    Abstract [en]

    Type I signal peptidase, with its vital role in bacterial viability, is a promising but underexploited antibacterial drug target. In the light of steadily increasing rates of antimicrobial resistance, we have developed novel macrocyclic lipopeptides, linking P2 and P1' by a boronic ester warhead, capable of inhibiting Escherichia coli type I signal peptidase (EcLepB) and exhibiting good antibacterial activity. Structural modifications of the macrocyclic ring, the peptide sequence and the lipophilic tail led us to 14 novel macrocyclic boronic esters. It could be shown that macrocyclization is well tolerated in terms of EcLepB inhibition and antibacterial activity. Among the synthesized macrocycles, potent enzyme inhibitors in the low nanomolar range (e.g. compound 42f, EcLepB IC50 = 29 nM) were identified also showing good antimicrobial activity (e.g. compound 42b, E. coli WT MIC = 16 μg/mL). The unique macrocyclic boronic esters described here were based on previously published linear lipopeptidic EcLepB inhibitors in an attempt to address cytotoxicity and hemolysis. We show herein that structural changes to the macrocyclic ring influence both the cytotoxicity and hemolytic activity suggesting that the P2 to P1' linker provide means for optimizing off-target effects. However, for the present set of compounds we were not able to separate the antibacterial activity and cytotoxic effect.

  • 331.
    Sänger-van de Griend, Cari Elise
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Chemistry.
    Enantiomeric separations by capillary electrophoresis in pharmaceutical analysis1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The chiral capillary electrophoresis mechanism is studied by evaluating the enantiomeric separations of a series of local anaesthetic analogues, the sixteen different optical isomers of a tetrapeptide and a series of glycyl, alanyl and leucyl dipeptides. The usefulness of mobility difference plots is appraised and important method parameters, such as the selection of the chiral selector, the chiral selector concentration, the chiral selector purity, the pH and the composition of the electrophoresis solution, are identified and discussed, bearing method robustness in mind. The evaluation of the mobility difference plots obtained for the eight enantiomer pairs of the tetrapeptide resulted in an extension of the mobility difference model. In the extended model the formation of enantiomer-chiral selector complexes with a stoichiometry higher than 1:1 is taken into account. With this model it is demonstrated that complex formation of one tetrapeptide molecule with more than one cyclodextrin molecule is a possible explanation for the experimentally obtained data.

    Cyclodextrins were evaluated as chiral selectors for dipeptides and have been shown to be applicable to the enantiomeric separation of aromatic and non-polar aliphatic dipeptides. By developing and validating an enantiomeric purity determination method for ropivacaine substance and products, it is shown that chiral capillary electrophoresis is a feasible technique for pharmaceutical analysis, which can offer an alternative and/or complement to chiral liquid chromatography.

  • 332.
    Sävmarker, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Palladium-Catalyzed Carbonylation and Arylation Reactions2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Palladium-catalyzed reactions have found widespread use in contemporary organic chemistry due to their impressive range of functional group tolerance and high chemo- and regioselectivity. The pioneering contributions to the development of the Pd-catalyzed C-C bond forming cross-coupling reaction were rewarded with the Nobel Prize in Chemistry in 2010. Today, this is a rapidly growing field, and the development of novel methods, as well as the theoretical understanding of the various processes involved are of immense importance for continued progress in this field.

    The aim of the work presented in this thesis was to develop novel palladium(0)- and palladium(II)-catalyzed reactions. The work involved in achieving this aim led to the development of a Mo(CO)6-mediated carbonylative Stille cross coupling reaction for the preparation of various deoxybenzoins. The protocol utilized convenient gas-free conditions to facilitate the carbonylative coupling of benzyl bromides and chlorides with aryl and heteroaryl stannanes. Mo(CO)6-assisted conditions were then used in the development of a general protocol suitable for the aminocarbonylation of aryl triflates. Both electron-poor and electron-rich triflates were coupled with primary, secondary and aryl amines. In addition, DMAP was found to be a beneficial additive when using sterically hindered or poorly nucleophilic amines.

    An efficient and convenient method for the synthesis of styrenes from arylboranes was developed, employing the relatively inexpensive vinyl acetate as the ethene source under Pd(II)-catalyzed conditions. The reaction mechanism was studied using ESI-MS, and a plausible catalytic cycle was proposed.

    A method for the oxidative Heck reaction employing aryltrifluoroborates and aryl MIDA boronates was also developed. Electron-rich and electron-poor olefins were regioselectively arylated under microwave-assisted conditions. Various arylboron species were identified in an ongoing reaction using ESI-MS.   

    Further investigations led to the development of a direct method for the synthesis of arylamidines from aryltrifluoroborates and cyanamides. Under Pd(II)-catalyzed conditions it was possible to insert the aryl into primary, secondary and tertiary cyanamides.

    Finally, a desulfitative method for the synthesis of aryl ketones was developed. A variety of aryl sulfinates were effectively inserted into alkyl- and aryl nitriles. The mechanism was further investigated using ESI-MS and a plausible catalytic cycle was proposed.

    List of papers
    1. Deoxybenzoins from Stille carbonylative cross-couplings using molybdenum hexacarbonyl
    Open this publication in new window or tab >>Deoxybenzoins from Stille carbonylative cross-couplings using molybdenum hexacarbonyl
    2010 (English)In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 51, no 52, p. 6886-6889Article in journal (Refereed) Published
    Abstract [en]

    Stille-type carbonylative cross-couplings, employing palladium catalysis and Mo(CO)6 as the carbon monoxide carrier, were used for the preparation of deoxybenzoins. Straightforward transformations were conveniently performed in closed vessels at 100 C, providing the products in good yields. Benzyl bromides and chlorides were used as coupling partners with aryl and heteroaryl stannanes. This mild three-component carbonylation employs the destabilizing agent DBU to promote smooth release of carbon monoxide from Mo(CO)6, which made this protocol operationally simple and minimized the formation of Stille diarylmethane products.

    Keywords
    Stille, molybdenum hexacarbonyl, deoxybenzoins, palladium
    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-167715 (URN)10.1016/j.tetlet.2010.10.115 (DOI)000285670400023 ()
    Available from: 2012-01-31 Created: 2012-01-31 Last updated: 2017-12-08Bibliographically approved
    2. Microwave-promoted aminocarbonylation of aryl triflates using Mo(CO)(6) as a solid CO source
    Open this publication in new window or tab >>Microwave-promoted aminocarbonylation of aryl triflates using Mo(CO)(6) as a solid CO source
    2008 (English)In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 49, no 42, p. 6115-6118Article in journal (Refereed) Published
    Abstract [en]

    Palladium-catalyzed carbonylations of aryl triflates with a range of nucleophiles using Mo(CO)(6) as a solid CO source were explored. The reactions proceeded smoothly providing moderate to good yields of the corresponding aryl amides, esters, or acylsulfonamides after only 20 min of microwave irradiation. The acyl transfer reagent 4-dimethylaminopyridine was found to promote some of the more difficult transformations. (C) 2008 Elsevier Ltd. All rights reserved.

    Keywords
    carbonylation, microwave, palladium, aryl triflate, DMAP
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-104379 (URN)10.1016/j.tetlet.2008.08.014 (DOI)000259883800024 ()0040-4039 (ISBN)
    Available from: 2009-05-28 Created: 2009-05-28 Last updated: 2017-12-13Bibliographically approved
    3. Synthesis of styrenes by palladium(II)-catalyzed vinylation of arylboronic acids and aryltrifluoroborates by using vinyl acetate
    Open this publication in new window or tab >>Synthesis of styrenes by palladium(II)-catalyzed vinylation of arylboronic acids and aryltrifluoroborates by using vinyl acetate
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    2009 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 15, no 18, p. 4630-4636Article in journal (Refereed) Published
    Abstract [en]

    Reactions of aromatic and heteroaromatic boronic acids or aryltrifluoroborate salts with vinyl acetate in the presence of a palladium(II) catalyst give the corresponding styrenes in good yields. This Heck reaction proceeds with microwave heating in less than 30 min at 140 degrees C in the absence of base and tolerates a variety of substituents. No palladium reoxidant is needed and the vinylation is performed under non-inert conditions. Mass spectrometry (electrospray ionization mass spectrometry (ESIMS) and tandem mass spectrometry   (MS/MS)) was used to identify cationic palladium-containing complexes in ongoing reactions. The key intermediates that have been detected, together with experiments that used deuterated vinyl acetate, support the existence of catalytically active palladium hydride species, and that it is the arylation of ethylene, not vinyl acetate, which   generates the styrene product. The mechanism of the reaction is discussed in terms of the palladium(II) intermediates mentioned above.

    Keywords
    Heck reaction, mass spectrometry, mechanistic studies, palladium, styrene
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-102918 (URN)10.1002/chem.200802744 (DOI)000265955200018 ()19274694 (PubMedID)
    Available from: 2009-05-13 Created: 2009-05-12 Last updated: 2017-12-13Bibliographically approved
    4. Oxidative Heck Reactions Using Aryltrifluoroborates and Aryl N-Methyliminodiacetic Acid (MIDA) Boronates
    Open this publication in new window or tab >>Oxidative Heck Reactions Using Aryltrifluoroborates and Aryl N-Methyliminodiacetic Acid (MIDA) Boronates
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    2012 (English)In: ChemistryOpen, ISSN 2191-1363, Vol. 1, no 3, p. 140-146Article in journal (Refereed) Published
    Place, publisher, year, edition, pages
    Weinheim: Wiley-VCH Verlagsgesellschaft, 2012
    Keywords
    Heck reactions, N-methyliminodiacetic acid (MIDA), oxidative reactions, palladium complexes, trifluoroborate
    National Category
    Organic Chemistry
    Research subject
    Chemistry with specialization in Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-167718 (URN)10.1002/open.201200007 (DOI)000328607400004 ()
    Funder
    Swedish Research Council
    Available from: 2012-01-31 Created: 2012-01-31 Last updated: 2017-12-08Bibliographically approved
    5. Direct Palladium(II)-Catalyzed Synthesis of Arylamidines from Aryltrifluoroborates
    Open this publication in new window or tab >>Direct Palladium(II)-Catalyzed Synthesis of Arylamidines from Aryltrifluoroborates
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    2012 (English)In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 14, no 9, p. 2394-2397Article in journal (Refereed) Published
    Abstract [en]

    A fast and convenient synthesis of arylamidines starting from readily available potassium aryltrifluoroborates and cyanamides is reported. The coupling was achieved by Pd(II)-catalysis in a one step 20 min microwave protocol using Pd(O2CCF3), 6-methyl-2,2'-bipyridyl, TFA, and MeOH, providing the corresponding arylamidines in moderate to excellent yields.

    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-167719 (URN)10.1021/ol300813c (DOI)000303492200052 ()
    Available from: 2012-01-31 Created: 2012-01-31 Last updated: 2017-12-08Bibliographically approved
    6. Microwave-Assisted Palladium(II)-Catalyzed Synthesis of Aryl Ketones from Aryl Sulfinates and Direct ESI-MS Studies Thereof
    Open this publication in new window or tab >>Microwave-Assisted Palladium(II)-Catalyzed Synthesis of Aryl Ketones from Aryl Sulfinates and Direct ESI-MS Studies Thereof
    2011 (English)In: ACS Catalysis, ISSN 2155-5435, Vol. 1, no 11, p. 1455-1459Article in journal (Refereed) Published
    Abstract [en]

    A fast palladium(II)-catalyzed and microwave-promoted procedure using 6-methyl-2,2'-bipyridyl as ligand to synthesize aryl ketones from aryl sulfinates and nitriles is described. More importantly, the first detailed investigation of the reaction mechanism using direct ESI-MS studies is reported.

    Keywords
    palladium, catalysis, desulfination, aryl sulfinates, aryl ketones, nitriles, ESI-MS, microwave
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-162466 (URN)10.1021/cs200428u (DOI)000296598000002 ()
    Available from: 2011-11-30 Created: 2011-11-30 Last updated: 2012-06-01Bibliographically approved
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  • 333.
    Talibov, Vladimir O
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Linkuvienė, Vaida
    Matulis, Daumantas
    Danielson, Helena U.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Kinetically Selective Inhibitors of Human Carbonic Anhydrase Isozymes I, II, VII, IX, XII, and XIII2016In: Journal of Medicinal Chemistry, ISSN 0022-2623, E-ISSN 1520-4804, Vol. 59, no 5, p. 2083-2093Article in journal (Refereed)
    Abstract [en]

    To get a better understanding of the possibility of developing selective carbonic anhydrase (CA) inhibitors, interactions between 17 benzenesulphonamide ligands and 6 human CAs (full-length CA I, II, VII, and XIII and catalytic domains of CA IX and XII) were characterized using surface plasmon resonance and fluorescent-based thermal shift assays. Kinetics revealed that the strongest binders had subnanomolar affinities with low dissociation rates (i.e., kd values around 1 × 10(-3) s(-1)) or were essentially irreversible. Chemodynamic analysis of the interactions highlighted an intrinsic mechanism of the CA-sulphonamide interaction kinetics and showed that slow dissociation rates were mediated by large hydrophobic contacts. The studied inhibitors demonstrated a high cross-reactivity within the protein family. However, according to chemical phylogenetic analysis developed for kinetic data, several ligands were found to be selective against certain CA isozymes, indicating that it should be possible to develop selective CA inhibitors suitable for clinical use.

  • 334.
    Tevell Åberg, Annica
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Medicinal Chemistry, Analytical Pharmaceutical Chemistry.
    Detection and Structure Elucidation of Drug Metabolites in Biological Samples using HPLC-MS/MS Techniques2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis describes the structure elucidation of drug metabolites in biological samples by the use of high performance liquid chromatography (HPLC) atmospheric pressure ionization (API) tandem mass spectrometry (MS/MS). Due to their different advantages, various mass analyzers have been used in the different experiments.

    The metabolism of clemastine, flutamide, and meloxicam were studied in vitro and/or in vivo in different species such as humans, dogs, and horses. Accurate mass measurements with the quadrupole-time of flight mass spectrometer and MSn data supplied by the ion trap instrument were useful in the structural investigation of the product ions of the drugs and their metabolites. Different scan modes of the triple quadrupole mass spectrometer resulted in great flexibility, selectivity, and sensitivity in the qualitative and semi-quantitative studies. Additionally, hydrogen/deuterium exchange and experiments with atmospheric pressure chemical ionization were conducted, and the fungus Cunninghamella elegans was utilized to produce amounts of drug metabolites sufficient for structural investigation.

    Six isomers of oxidized clemastine were detected and characterized in C. elegans incubations and their retention times and mass spectral data were compared to the metabolites detected in urine samples. Two of the metabolites were concluded to be diastereomeric N-oxides.

    In urine from horses treated with meloxicam, the peak of 5'-hydroxymethylmeloxicam resulted in much higher intensity than the parent drug or the other metabolites, and it was detectable for at least 14 days after the last dose in some of the horses. That is useful information in the development of analytical methods for the detection of prohibited use of meloxicam.

    A mercapturic acid conjugate of hydroxyflutamide was detected in urine from cancer patients, which indicated that a reactive metabolite was formed. This metabolite could be responsible for the adverse events reported for flutamide.

    The results from the four papers included in the thesis clearly demonstrate the usefulness and the flexibility of the HPLC-API-MS/MS technique.

    List of papers
    1. Identification of some new clemastine metabolites in dog, horse, and human urine with liquid chromatography/tandem mass spectrometry.
    Open this publication in new window or tab >>Identification of some new clemastine metabolites in dog, horse, and human urine with liquid chromatography/tandem mass spectrometry.
    2004 (English)In: Rapid Commun Mass Spectrom, ISSN 0951-4198, Vol. 18, no 19, p. 2267-72Article in journal (Other scientific) Published
    Identifiers
    urn:nbn:se:uu:diva-67268 (URN)15384147 (PubMedID)
    Available from: 2004-11-11 Created: 2004-11-11 Last updated: 2011-01-12
    2. Structure elucidation of N-oxidized clemastine metabolites by HPLC-MS-MS and the use of Cunninghamella elegans to facilitate drug metabolite identification
    Open this publication in new window or tab >>Structure elucidation of N-oxidized clemastine metabolites by HPLC-MS-MS and the use of Cunninghamella elegans to facilitate drug metabolite identification
    (English)Manuscript (Other (popular science, discussion, etc.))
    Keywords
    HPLC-MS/MS, hydrogen/deuterium exchange, N-oxidation, Clemastine, metabolites
    Identifiers
    urn:nbn:se:uu:diva-98343 (URN)
    Available from: 2009-02-19 Created: 2009-02-19 Last updated: 2010-01-14
    3. Flutamide metabolism in four different species in vitro and identification of flutamide metabolites in human patient urine by high performance liquid chromatography/tandem mass spectrometry.
    Open this publication in new window or tab >>Flutamide metabolism in four different species in vitro and identification of flutamide metabolites in human patient urine by high performance liquid chromatography/tandem mass spectrometry.
    Show others...
    2006 (English)In: Drug Metab Dispos, ISSN 0090-9556, Vol. 34, no 6, p. 984-92Article in journal (Refereed) Published
    Keywords
    Androgen Antagonists/*metabolism/therapeutic use/urine, Animals, Antineoplastic Agents; Hormonal/*metabolism/therapeutic use/urine, Biotransformation, Chromatography; Liquid, Comparative Study, Dogs, Flutamide/*analogs & derivatives/*metabolism/standards/therapeutic use/urine, Glucuronidase, Humans, In Vitro, Male, Microsomes; Liver/metabolism, Prostate/metabolism, Prostatic Neoplasms/drug therapy/*metabolism/urine, Rats, Spectrometry; Mass; Electrospray Ionization, Swine
    Identifiers
    urn:nbn:se:uu:diva-80893 (URN)16540588 (PubMedID)
    Available from: 2007-03-03 Created: 2007-03-03 Last updated: 2011-01-11
    4. A mass spectromeric study on meloxicam metabolism in horses and the fungus Cunninghamella elegans, and the relevance of this microbial system as a model of drug metabolism in the horse
    Open this publication in new window or tab >>A mass spectromeric study on meloxicam metabolism in horses and the fungus Cunninghamella elegans, and the relevance of this microbial system as a model of drug metabolism in the horse
    2009 (English)In: Journal of Mass Spectrometry, ISSN 1076-5174, E-ISSN 1096-9888, Vol. 44, no 7, p. 1026-1037Article in journal (Refereed) Published
    Abstract [en]

    This paper describes a study where the metabolism of the non-steroidal   anti-inflammatory drug meloxicam was investigated in six horses and in  the filamentous fungus Cunninghamella elegans. The metabolites identified were compared between the species, and then the fungus was  used to produce larger amounts of the metabolites for future use as   reference material. C. elegans proved to be a good model of phase I   meloxicam metabolism in horses since all four metabolites found were   the same in both species. Apart from the two main metabolites,   5'-hydroxymethylmeloxicam and 5'-carboxymeloxicam, a second isomer of   hydroxymeloxicam and dihydroxylated meloxicam were detected for the   first time in horse urine and the microbial incubations. Phase II   metabolites were not discovered in the C. elegans samples but   hydroxymeloxicam glucuronide was detected intact in horse urine for the   first time in this study. Urine from six horses was further analyzed in   a semi-quantitative sense and 5'-hydroxymethylmeloxicam gave peaks with   much higher intensity compared to the parent drug and the other   metabolites, and was detected for at least 14 days after the last given   dose in some of the horses. From the results presented in this article,   we suggest that analytical methods developed for the detection of   meloxicam in horse urine after prohibited use should focus on the   5'-hydroxymethyl metabolite and that C. elegans can be used to produce  large amounts of this metabolite for potential future use as a reference compound.

    Keywords
    Meloxicam, metabolism, mass spectrometry, horse, Cunninghamella elegans
    National Category
    Pharmaceutical Sciences
    Research subject
    Analytical Pharmaceutical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-98287 (URN)10.1002/jms.1575 (DOI)000268505500003 ()
    Available from: 2009-02-19 Created: 2009-02-18 Last updated: 2018-01-13Bibliographically approved
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  • 335.
    Thorsteinsdóttir, Margrét
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Chemistry.
    Separation of peptides by capillary electrophoresis: Application of chemometrics for evaluation of separation performance in micellar electrokinetic chromatography1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The separation of enkephalin-related peptides and protein kinase A peptide substrates werestudied in micellar electrokinetic chromatography and compared with capillary zoneelectrophoresis. Special interest was focused on systems where the electroosmosis wasreversed in combination with neutral micellar agents. Such systems involve the unique combination of minimizing surface interactions by electrostatic effects and increasing themigration time window. This was accomplished either by addition of cationic monomericamines to the background electrolyte or by using fused silica capillaries modified byimmobilizing an amine to the surface.

    The selectivities were enhanced by adding anionic taurodeoxycholate micelles to the BGE.The efficiencies obtained were highly dependent on the extent of distribution of the peptides tothe micellar phase. The effect of experimental factors that cause band broadening duringseparation were evaluated by fractional factorial design and response surface modelling. Partialleast square (PLS) regression analysis revealed that very high efficiencies were obtained forpeptides with low distribution to the micelles, while the efficiencies drastically decreased forpeptides strongly associated to the micelles, probably due to slow sorption-desorption kinetics.

    The separation of enkephalin-related peptides in a system with anionic sodium dodecylmicelles (SDS) was optimized by utilizing experimental design and response surfacemodelling. Such strategies have the advantages of greatly reducing the number of experimentsand allowing identification of interaction effects between the variables. The effect ofacetonitrile was studied, in four different concentration domains, together with SDSconcentration, temperature and the ionic strength of the buffer via central composite design,and related to resolution, migration factor and migration time window utilizing PLS-regression. The results revealed a complex system with very different influences of theexperimental variables in respective domain. The effect of acetonitrile is highly non-linear insystems of this kind and dependent on the temperature used. A change in the thermodynamicsof the distribution behaviour was observed at increasing acetonitrile concentrations. Further,the relationships between different parameters that influence the resolution were investigatedby principal component analysis.

  • 336.
    Torstensson, Richard
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmaceutical Chemistry.
    Functional regulation of the dopaminergic system in vivo: Experimental and clinical studies with positron emission tomography1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Positron emission tomography (PET) is a non-invasive imaging technique used to quantitate the kinetics of a radiotracer in such physiological processes as receptor binding and enzyme activity. Radiolabelled L-DOPA has previously been used as a tracer for the dopaminergic system. The focus of the present study was to investigate the validity and feasibility of the 11C-labelled L-DOPA to measure aromatic amino acid decarboxylase (AADC) activity as an indicator of the functional tone of the presynaptic dopaminergic system in vivo. The regulation of the presynaptic dopaminergic system was studied in rhesus monkeys, as well as in humans in the healthy and diseased states.

    The intra- and inter-individual variations of the striatal influx rate constant for L-[β-11C]DOPA, i.e. Ki, measured with PET were found to be 10 and 15% between days, respectively. Furthermore, in rhesus monkeys, the Ki value was shown to decrease slightly (1 to 2% per year) as a function of time. Radiolabelled L-DOPA and its 6-fluoroanalogue were compared as PET tracers. Differences in the peripheral metabolism of L-DOPA and the fluorinated analogue were confirmed. The modulating effects of 6R-BH4 on L-[β-11C]DOPA Ki were only found for the L-6-fluorodopa tracer when animals had been pretreated with a COMT inhibitor.

    Pharmacological treatments induced changes in the L-[β-11C]DOPA Ki. The dopamine receptor agonist, apomorphine, decreased the striatal Ki value and L-DOPA as well as 6R-BH4, a co-factor for tyrosine hydroxylase, increased the Ki values. Moreover, the effects of these drugs on the striatal Ki value showed significant baseline dopaminergic state-dependent effects. The regulating effect on the L-[β-11C]DOPA Ki induced by different pharmacological treatments was shown to correlate with changes in AADC activity measured in rat brain homogenates.

    An intriguing new compound, (-)-OSU6162, was investigated with respect to its functional effects in the regulation of the presynaptic dopaminergic system. The compound induced a normalising effect on striatal L-[β-11C]DOPA Ki values, i.e. (-)-OSU6162 increased the striatal Ki value in monkeys with initial low values and decreased the Ki values in monkeys with initial high values.

    In patients with Parkinson's disease (PD), marked differences in the functional regulation of the presynaptic dopaminergic tone were found in patients with early and advanced disease. After therapeutic levodopa infusions, patients with advanced PD showed an increase in striatal L-[β-11C]DOPA Ki values; in patients with early PD, levodopa induced a decrease in striatal Ki values. A diminished presynaptic autoreceptor function in advanced PD was proposed and demonstrated in a clinical study using a therapeutic apomorphine challenge.

    In conclusion, the radiotracer L-[β-11C]DOPA was shown not only to measure the AADC integrity in the presynaptic dopaminergic system but also to reflect the functional tone of this neurotransmitter system in vivo.

  • 337.
    Ujan, Rabail
    et al.
    Univ Sindh, Dr MA Kazi Inst Chem, Jamshoro 76080, Pakistan.
    Saeed, Aamer
    Quaid I Azam Univ, Dept Chem, Islamabad 45320, Pakistan.
    Channar, Pervaiz Ali
    Quaid I Azam Univ, Dept Chem, Islamabad 45320, Pakistan.
    Larik, Fayaz Ali
    Quaid I Azam Univ, Dept Chem, Islamabad 45320, Pakistan.
    Abbas, Qamar
    Univ Sindh, Dept Physiol, Jamshoro 76080, Pakistan.
    Alajmi, Mohamed F.
    King Saud Univ, Dept Pharmacognosy, Coll Pharm, Riyadh 11451, Saudi Arabia.
    El-Seedi, Hesham
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi.
    Rind, Mahboob Ali
    Univ Sindh, Dr MA Kazi Inst Chem, Jamshoro 76080, Pakistan.
    Hassan, Mubashir
    Kongju Natl Univ, Coll Nat Sci, Dept Biol Sci, Gongju 314701, Chungnam, South Korea.
    Raza, Hussain
    Kongju Natl Univ, Coll Nat Sci, Dept Biol Sci, Gongju 314701, Chungnam, South Korea.
    Seo, Sung-Yum
    Kongju Natl Univ, Coll Nat Sci, Dept Biol Sci, Gongju 314701, Chungnam, South Korea.
    Drug-1,3,4-Thiadiazole Conjugates as Novel Mixed-Type Inhibitors of Acetylcholinesterase: Synthesis, Molecular Docking, Pharmacokinetics, and ADMET Evaluation2019In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 24, no 5, article id 860Article in journal (Refereed)
    Abstract [en]

    A small library of new drug-1,3,4-thiazidazole hybrid compounds (3a-3i) was synthesized, characterized, and assessed for their acetyl cholinesterase enzyme (AChE) inhibitory and free radical scavenging activities. The newly synthesized derivatives showed promising activities against AChE, especially compound 3b (IC50 18.1 +/- 0.9 nM), which was the most promising molecule in the series, and was substantially more active than the reference drug (neostigmine methyl sulfate; IC50 2186.5 +/- 98.0 nM). Kinetic studies were performed to elucidate the mode of inhibition of the enzyme, and the compounds showed mixed-type mechanisms for inhibiting AChE. The Ki of 3b (0.0031 mu M) indicates that it can be very effective, even at low concentrations. Compounds 3a-3i all complied with Lipinski's Rule of Five, and showed high drug-likeness scores. The pharmacokinetic parameters revealed notable lead-like properties with insignificant liver and skin-penetrating effects. The structure-activity relationship (SAR) analysis indicated pi-pi interactions with key amino acid residues related to Tyr124, Trp286, and Tyr341.

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  • 338.
    Ul Haq, Faraz
    et al.
    Univ Karachi, Int Ctr Chem & Biol Sci, HEJ Res Inst Chem, Karachi 75270, Pakistan.
    Ali, Arslan
    Univ Karachi, Int Ctr Chem & Biol Sci, Dr Panjwani Ctr Mol Med & Drug Res, Karachi 75270, Pakistan.
    Khan, Muhammad Noman
    Univ Karachi, Int Ctr Chem & Biol Sci, HEJ Res Inst Chem, Karachi 75270, Pakistan.
    Shah, Syed Muhammad Zaki
    Univ Karachi, Int Ctr Chem & Biol Sci, HEJ Res Inst Chem, Karachi 75270, Pakistan.
    Kandel, Ram Chandra
    Tribhuvan Univ, Cent Dept Chem, Kathmandu, Nepal.
    Aziz, Nudrat
    Univ Karachi, Int Ctr Chem & Biol Sci, HEJ Res Inst Chem, Karachi 75270, Pakistan.
    Adhikari, Achyut
    Tribhuvan Univ, Cent Dept Chem, Kathmandu, Nepal.
    Choudhary, M. Iqbal
    Univ Karachi, Int Ctr Chem & Biol Sci, HEJ Res Inst Chem, Karachi 75270, Pakistan;Univ Karachi, Int Ctr Chem & Biol Sci, Dr Panjwani Ctr Mol Med & Drug Res, Karachi 75270, Pakistan;King Abdulaziz Univ, Fac Sci, Dept Biochem, Jeddah 21452, Saudi Arabia.
    Atta-ur-Rahman,
    El-Seedi, Hesham
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi. Alrayan Med Coll, Medina 42541, Saudi Arabia.
    Musharraf, Syed Ghulam
    Univ Karachi, Int Ctr Chem & Biol Sci, HEJ Res Inst Chem, Karachi 75270, Pakistan;Univ Karachi, Int Ctr Chem & Biol Sci, Dr Panjwani Ctr Mol Med & Drug Res, Karachi 75270, Pakistan.
    Metabolite Profiling and Quantitation of Cucurbitacins in Cucurbitaceae Plants by Liquid Chromatography coupled to Tandem Mass Spectrometry2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 15992Article in journal (Refereed)
    Abstract [en]

    Cucurbitaceae is an important plant family because many of its species are consumed as food, and used in herbal medicines, cosmetics, etc. It comprises annual vines and is rich in various bioactive principles which include the cucurbitacins. These steroidal natural products, derived from the triterpene cucurbitane, are mainly the bitter principles of the family Cucurbitaceae. Their biological activities include anti-inflammatory, hepatoprotective, and anti-cancer activities. A total of 10 species belonging to 6 genera of the Cucurbitaceae family along with Cissampelos pareira (Menispermaceae) were included in this study. A comprehensive profiling of certain natural products was developed using HPLC-QTOF-MS/MS analysis and a distribution profile of several major natural products in this family was obtained. A total of 51 natural products were detected in both positive and negative ionization modes, based on accurate masses and fragmentation patterns. Along with this, quantitation of four bioactive cucurbitacins, found in various important plants of the Cucurbitaceae family, was carried out using multiple reaction monitoring (MRM) approach on an ion trap mass spectrometer. Cucurbitacin Q was found to be the most abundant in C. pareira, while Citrullus colocynthis contained all four cucurbitacins in abundant quantities. The developed quantitation method is simple, rapid, and reproducible.

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  • 339. Valero-Esquitino, Verónica
    et al.
    Lucht, Kristin
    Namsolleck, Pawel
    Monnet-Tschudi, Florianne
    Stubbe, Tobias
    Lucht, Franziska
    Liu, Meng
    Ebner, Friederike
    Brandt, Christine
    Danyel, Leon A
    Villela, Daniel C
    Paulis, Ludovit
    Thoene-Reineke, Christa
    Dahlöf, Björn
    Hallberg, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Unger, Thomas
    Sumners, Colin
    Steckelings, U Muscha
    Direct angiotensin type 2 receptor (AT2R) stimulation attenuates T-cell and microglia activation and prevents demyelination in experimental autoimmune encephalomyelitis in mice2015In: Clinical Science, ISSN 0143-5221, E-ISSN 1470-8736, Vol. 128, no 2, p. 95-109Article in journal (Refereed)
    Abstract [en]

    In the present study, we evaluated stimulation of the angiotensin type 2 receptor (AT2R) by the selective non-peptide agonist Compound 21 (C21) as a novel therapeutic concept for the treatment of multiple sclerosis using the model of experimental autoimmune encephalomyelitis (EAE) in mice. C57BL-6 mice were immunized with myelin-oligodendrocyte peptide and treated for 4 weeks with C21 (0.3 mg/kg/day i.p.). Potential effects on myelination, microglia and T-cell composition were estimated by immunostaining and FACS analyses of lumbar spinal cords. The in vivo study was complemented by experiments in aggregating brain cell cultures and microglia in vitro. In the EAE model, treatment with C21 ameliorated microglia activation and decreased the number of total T-cells and CD4+ T-cells in the spinal cord. Fluorescent myelin staining of spinal cords further revealed a significant reduction in EAE-induced demyelinated areas in lumbar spinal cord tissue after AT2R stimulation. C21-treated mice had a significantly better neurological score than vehicle-treated controls. In aggregating brain cell cultures challenged with lipopolysaccharide (LPS) plus interferon-γ (IFNγ), AT2R stimulation prevented demyelination, accelerated re-myelination and reduced the number of microglia. Cytokine synthesis and nitric oxide production by microglia in vitro were significantly reduced after C21 treatment. These results suggest that AT2R stimulation protects the myelin sheaths in autoimmune central nervous system inflammation by inhibiting the T-cell response and microglia activation. Our findings identify the AT2R as a potential new pharmacological target for demyelinating diseases such as multiple sclerosis.

  • 340.
    Valitalo, Pyry
    et al.
    Leiden Univ, Div Pharmacol, Leiden, Netherlands..
    Kokki, Merja
    Kuopio Univ Hosp, Dept Anesthesia & Operat Serv, POB 100, FI-70029 Kuopio, Finland.;Univ Eastern Finland, Sch Med, Kuopio, Finland..
    Ranta, Veli-Pekka
    Univ Eastern Finland, Sch Pharm, Kuopio, Finland..
    Olkkola, Klaus T.
    Univ Helsinki, Dept Anesthesiol Intens Care & Pain Med, Helsinki, Finland.;Helsinki Univ Hosp, Helsinki, Finland..
    Hooker, Andrew C.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Kokki, Hannu
    Kuopio Univ Hosp, Dept Anesthesia & Operat Serv, POB 100, FI-70029 Kuopio, Finland.;Univ Eastern Finland, Sch Med, Kuopio, Finland..
    Maturation of Oxycodone Pharmacokinetics in Neonates and Infants: a Population Pharmacokinetic Model of Three Clinical Trials2017In: Pharmaceutical research, ISSN 0724-8741, E-ISSN 1573-904X, Vol. 34, no 5, p. 1125-1133Article in journal (Refereed)
    Abstract [en]

    Purpose The aim of the current population pharmacokinetic study was to quantify oxycodone pharmacokinetics in children ranging from preterm neonates to children up to 7 years of age. Methods Data on intravenous or intramuscular oxycodone administration were obtained from three previously published studies (n = 119). The median [range] postmenstrual age of the subjects was 299 days [170 days-7.8 years]. A population pharmacokinetic model was built using 781 measurements of oxycodone plasma concentration. The model was used to simulate repeated intravenous oxycodone administration in four representative infants covering the age range from an extremely preterm neonate to 1-year old infant. Results The rapid maturation of oxycodone clearance was best described with combined allometric scaling and maturation function. Central and peripheral volumes of distribution were nonlinearly related to bodyweight. The simulations on repeated intravenous administration in virtual patients indicated that oxycodone plasma concentration can be kept between 10 and 50 ng/ml with a high probability when the maintenance dose is calculated using the typical clearance and the dose interval is 4 h. Conclustions Oxycodone clearance matures rapidly after birth, and between-subject variability is pronounced in neonates. The pharmacokinetic model developed may be used to evaluate different multiple dosing regimens, but the safety of repeated doses should be ensured.

  • 341.
    Vallin, Karl S. A.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Regioselective Heck Coupling Reactions: Focus on Green Chemistry2003Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Carbon-carbon bond formation reactions are among the most important processes in chemistry, as they represent key steps in the synthesis of more complex molecules from simple precursors. This thesis describes mainly the development of novel regioselective applications of the mild and versatile palladium-catalyzed carbon-carbon coupling method, commonly known as the Heck reaction. In addition, this thesis will focus on environmentally friendly developments of the Heck reaction.

    Novel ligand-controlled internal Heck vinylations of vinyl ethers and enamides to form branched electron-rich dienes were performed with high regioselectivity. The vinylation of 2-hydroxyethyl vinyl ether permits a chemoselective transformation of a vinylic triflate or bromide into a blocked α,β-unsaturated methyl ketone. Furthermore, a simple separation of the palladium catalyst was achieved with new fluorous-tagged bidentate ligands in combination with fluorous solid phase extraction. The reaction times could be reduced up to 1000 times with controlled microwave heating in the palladium-catalyzed reactions with, in the majority of cases, retained, high selectivity.

    The development of a “green” regioselective arylation and vinylation method relying on an aqueous DMF-potassium carbonate system and excluding the toxic thallium salt has been accomplished. Ionic liquids as the versatile and environmentally friendly class of solvents have been used in rapid phosphine-free terminal Heck arylations with controlled microwave heating. Recycling of the catalytic medium was achieved after a simple product purification.

    List of papers
    1. Highly Selective Palladium-Catalyzed Synthesis of Protected a,ß-Unsaturated Methyl Ketones and 2-Alkoxy-1,3-Butadienes: High-Speed Chemistry by Microwave Flash Heating
    Open this publication in new window or tab >>Highly Selective Palladium-Catalyzed Synthesis of Protected a,ß-Unsaturated Methyl Ketones and 2-Alkoxy-1,3-Butadienes: High-Speed Chemistry by Microwave Flash Heating
    2000 (English)In: J. Org. Chem., Vol. 65, no 15, p. 4537-4542Article in journal (Refereed) Published
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-90267 (URN)
    Available from: 2003-04-24 Created: 2003-04-24 Last updated: 2013-07-04Bibliographically approved
    2. New Regioselective Heck-Vinylation with Enamides. Synthesis and Investigation of Fluorous Tagged Bidentate Ligands for Fast Separation
    Open this publication in new window or tab >>New Regioselective Heck-Vinylation with Enamides. Synthesis and Investigation of Fluorous Tagged Bidentate Ligands for Fast Separation
    Show others...
    (English)In: J. Org. Chem.Article in journal (Refereed) Submitted
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-90268 (URN)
    Available from: 2003-04-24 Created: 2003-04-24 Last updated: 2013-07-04Bibliographically approved
    3. Aqueous DMF-Potassium Carbonate as a Substitute for Thallium and Silver Additives in the Palladium-Catalyzed Conversion of Aryl Bromides to Acetyl Arenes
    Open this publication in new window or tab >>Aqueous DMF-Potassium Carbonate as a Substitute for Thallium and Silver Additives in the Palladium-Catalyzed Conversion of Aryl Bromides to Acetyl Arenes
    2001 (English)In: J. Org. Chem., Vol. 66, no 12, p. 4340-4343Article in journal (Refereed) Published
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-90269 (URN)
    Available from: 2003-04-24 Created: 2003-04-24 Last updated: 2013-07-04Bibliographically approved
    4. High-Speed Heck Reactions in Ionic Liquid with Controlled Microwave Heating
    Open this publication in new window or tab >>High-Speed Heck Reactions in Ionic Liquid with Controlled Microwave Heating
    2002 (English)In: J. Org. Chem., Vol. 67, no 17, p. 6243-6246Article in journal (Refereed) Published
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-90270 (URN)
    Available from: 2003-04-24 Created: 2003-04-24 Last updated: 2013-07-04Bibliographically approved
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  • 342.
    van Kuilenburg, André
    et al.
    Univ Amsterdam, Emma Childrens Hosp, Lab Genet Metabol Dis Pediat & Clin Genet, Dept Clin Chem,Acad Med Ctr, Amsterdam, Netherlands.
    Tarailo-Graovac, Maja
    Univ Calgary, Cumming Sch Med, Dept Biochem, Calgary, AB, Canada; Univ Calgary, Cumming Sch Med, Dept Mol Biol, Calgary, AB, Canada; Univ Calgary, Cumming Sch Med, Dept Med Genet, Calgary, AB, Canada; Univ Calgary, Alberta Childrens Hosp, Res Inst, Calgary, AB, Canada.
    Meijer, Judith
    Univ Amsterdam, Emma Childrens Hosp, Lab Genet Metabol Dis Pediat & Clin Genet, Dept Clin Chem,Acad Med Ctr, Amsterdam, Netherlands.
    Drogemoller, Britt
    Univ British Columbia, Ctr Mol Med & Therapeut, Dept Pediat, Vancouver, BC, Canada; Univ British Columbia, Ctr Mol Med & Therapeut, Dept Med Genet, Vancouver, BC, Canada.
    Vockley, Gerard
    Univ Pittsburgh, Sch Med, Dept Pediat, Pittsburgh, PA 15261 USA; Univ Pittsburgh, Grad Sch Publ Hlth, Pittsburgh, PA USA.
    Maurer, Dirk
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Dobritzsch, Doreen
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Ross, Colin
    Univ British Columbia, Ctr Mol Med & Therapeut, Dept Pediat, Vancouver, BC, Canada; Univ British Columbia, Ctr Mol Med & Therapeut, Dept Med Genet, Vancouver, BC, Canada.
    Wasserman, Wyeth
    Univ British Columbia, Ctr Mol Med & Therapeut, Dept Pediat, Vancouver, BC, Canada; Univ British Columbia, Ctr Mol Med & Therapeut, Dept Med Genet, Vancouver, BC, Canada.
    Meinsma, Rutger
    Univ Amsterdam, Emma Childrens Hosp, Lab Genet Metabol Dis Pediat & Clin Genet, Dept Clin Chem,Acad Med Ctr, Amsterdam, Netherlands.
    Zoetekouw, Lida
    Univ Amsterdam, Emma Childrens Hosp, Lab Genet Metabol Dis Pediat & Clin Genet, Dept Clin Chem,Acad Med Ctr, Amsterdam, Netherlands.
    van Karnebeek, Clara
    Univ Amsterdam, Emma Childrens Hosp, Lab Genet Metabol Dis Pediat & Clin Genet, Dept Clin Chem,Acad Med Ctr, Amsterdam, Netherlands; Univ British Columbia, Ctr Mol Med & Therapeut, Dept Pediat, Vancouver, BC, Canada; Univ British Columbia, Ctr Mol Med & Therapeut, Dept Med Genet, Vancouver, BC, Canada.
    Genome sequencing reveals a novel genetic mechanism underlying dihydropyrimidine dehydrogenase deficiency: A novel missense variant c.1700G > A and a large intragenic inversion in DPYD spanning intron 8 to intron 122018In: Human Mutation, ISSN 1059-7794, E-ISSN 1098-1004, Vol. 39, no 7, p. 947-953Article in journal (Refereed)
    Abstract [en]

    Dihydropyrimidine dehydrogenase (DPD) deficiency is associated with a variable clinical presentation. A family with three DPD-deficient patients presented with unusual clinical phenotypes including pregnancy-induced symptoms, transient visual impairment, severe developmental delay, cortical blindness, and delayed myelination in the brain. DPYD Sanger sequencing showed heterozygosity for the c.1905+1G>A mutation and a novel missense variant c.1700G>A (p.G567E). The recombinantly expressed p.G567E DPD variant showed increased temperature lability probably caused by structural rearrangements within the DPD protein. Genome sequencing of the affected son established compound heterozygosity for the c.1700G>A and an imperfect 115,731bp inversion with breakpoints at chr1: 98,113,121 (intron 8) and chr1: 97,997,390 (intron 12) of the DPYD associated with a 4bp deletion (chr1: 97,997,386_97,997,389del). Whole exome and mitochondrial DNA analyses for the mother and daughter did not reveal additional mutated genes of significance. Thus, an inversion in DPYD should be considered in patients with an inconclusive genotype or unusual clinical phenotype.

  • 343. Verbeek, Joost
    et al.
    Eriksson, Jonas
    Department of Radiology & Nuclear Medicine, VU University Medical Center, P.O. box 7057, 1007, MB, Amsterdam, The Netherlands.
    Syvänen, Stina
    Division of Pharmacology, LACDR, Leiden University, Leiden, The Netherlands.
    Huisman, Marc
    Schuit, Robert C
    Molthoff, Carla F M
    Voskuyl, Rob A
    de Lange, Elizabeth C
    Lammertsma, Adriaan A
    Windhorst, Albert D
    Synthesis and preliminary preclinical evaluation of fluorine-18 labelled isatin-4-(4-methoxyphenyl)-3-thiosemicarbazone ([18F]4FIMPTC) as a novel PET tracer of P-glycoprotein expression.2018In: EJNMMI radiopharmacy and chemistry, ISSN 2365-421X, Vol. 3, article id 11Article in journal (Refereed)
    Abstract [en]

    Background: Several P-glycoprotein (P-gp) substrate tracers are available to assess P-gp function in vivo, but attempts to develop a tracer for measuring expression levels of P-gp have not been successful. Recently, (Z)-2-(5-fluoro-2-oxoindolin-3-ylidene)-N-(4-methoxyphenyl)hydrazine-carbothioamide was described as a potential selective P-gp inhibitor that is not transported by P-gp. Therefore, the purpose of this study was to radiolabel two of its analogues and to assess their potential for imaging P-gp expression using PET.

    Results: [18F]2-(4-fluoro-2-oxoindolin-3-ylidene)-N-(4-methoxyphenyl)hydrazine-carbothioamide ([18F]5) and [18F]2-(6-fluoro-2-oxoindolin-3-ylidene)-N-(4-methoxyphenyl)hydrazine-carbothioamide ([18F]6) were synthesized and both their biodistribution and metabolism were evaluated in rats. In addition, PET scans were acquired in rats before and after tariquidar (P-gp inhibitor) administration as well as in P-gp knockout (KO) mice.Both [18F]5 and [18F]6 were synthesized in 2-3% overall yield, and showed high brain uptake in ex vivo biodistribution studies. [18F]6 appeared to be metabolically unstable in vivo, while [18F]5 showed moderate stability with limited uptake of radiolabelled metabolites in the brain. PET studies showed that transport of [18F]5 across the blood-brain barrier was not altered by pre-treatment with the P-gp inhibitor tariquidar, and uptake was significantly lower in P-gp KO than in wild-type animals and indeed transported across the BBB or bound to P-gp in endothelial cells.

    Conclusion: In conclusion, [18F]5 and [18F]6 were successfully and reproducibly synthesized, albeit with low radiochemical yields. [18F]5 appears to be a radiotracer that binds to P-gp, as showed in P-gp knock-out animals, but is not a substrate for P-gp.

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  • 344.
    Vikeved, Elisabet
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Drug discovery against leishmaniasis: Bio- and chemoinformatic guided strategies for target evaluation and hit identification2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Leishmaniasis is a neglected tropical disease mainly affecting poor people in developing countries. It is caused by infections of flagellated protozoa belonging to genus Leishmania. The few available drugs are associated with problems such as low effectiveness, severe side effects and resistance development. The overall aim of this thesis is to aid in drug discovery against leishmaniasis – primarily using bio- and chemoinformtic approaches.

    In the first part of the thesis potential drug targets in Leishmania parasites were identified and hits against these targets were thereafter suggested. In paper I bioinformatics together with experimental work were used to evaluate lateral gene transfer (LGT) in genus Leishmania. LGTs of prokaryote origin often lack human homologs, and are therefore hypothesized to be valuable drug targets. LGT in genus Leishmania is shown to be a dynamic process in which some acquired genes are conserved in the recipient genomes and others are degraded and eventually lost. Some LGTs have also undergone pseudogenization. It is thus important to evaluate LGT products before exploring them as potential drug targets.

    In paper II ligand-based virtual screening and molecular docking were used to suggest potential hits against the LGT product pteridine reductase 1 (PTR1) and the two-domain enzyme dihydrofolate reductase-thymidylate synthase (DHFR-TS) both involved in folate metabolism. DHFR-TS is not encoded by an LGT but it has been hypothesised that several enzymes in the folate pathway need to be inhibited to affect the viability of Leishmania parasites. One potential hit compound against PTR1 and the DHFR-domain and four hit compounds against PTR1 and the TS-domain were identified and tested on Leishmania tropica promastigotes. The suggested PTR1/TS inhibitors had no effect in the promastigote assay, however one of them enhanced the effect of the PTR1/DHFR inhibitor, which also had effect on its own.

    In the second part of the project, focus shifted towards predictions of targets for compounds with known anti-leishmanial activity but unknown mechanisms of actions. In paper III a ligand-based-target fishing (LBTF) method was developed. The reference compounds were metabolites to metabolic enzymes and similarities were assessed with Euclidean distance calculations in chemical property space. The LBTF approach was used to suggest potential targets to a set of anti-leishmanial agents retrieved from ChEMBL-database. The theory behind the LBTF method developed in paper III was also used in paper IV to predict targets of two sponge-derived alkaloids that where shown to have anti-leishmanial activity.

    List of papers
    1. The Dynamics of Lateral Gene Transfer in Genus Leishmania - A Route for Adaptation and Species Diversification
    Open this publication in new window or tab >>The Dynamics of Lateral Gene Transfer in Genus Leishmania - A Route for Adaptation and Species Diversification
    2016 (English)In: PLoS Neglected Tropical Diseases, ISSN 1935-2727, E-ISSN 1935-2735, Vol. 10, no 1, article id e0004326Article in journal (Refereed) Published
    Abstract [en]

    Background The genome of Leishmania major harbours a comparably high proportion of genes of prokaryote origin, acquired by lateral gene transfer (LGT). Some of these are present in closely related trypanosomatids, while some are detected in Leishmania only. We have evaluated the impact and destiny of LGT in genus Leishmania. Methodology/Principal Findings To study the dynamics and fate of LGTs we have performed phylogenetic, as well as nucleotide and amino acid composition analyses within orthologous groups of LGTs detected in Leishmania. A set of universal trypanosomatid LGTs was added as a reference group. Both groups of LGTs have, to some extent, ameliorated to resemble the recipient genomes. However, while virtually all of the universal trypanosomatid LGTs are distributed and conserved in the entire genus Leishmania, the LGTs uniquely present in genus Leishmania are more prone to gene loss and display faster rates of evolution. Furthermore, a PCR based approach has been employed to ascertain the presence of a set of twenty LGTs uniquely present in genus Leishmania, and three universal trypanosomatid LGTs, in ten additional strains of Leishmania. Evolutionary rates and predicted expression levels of these LGTs have also been estimated. Ten of the twenty LGTs are distributed and conserved in all species investigated, while the remainder have been subjected to modifications, or undergone pseudogenization, degradation or loss in one or more species. Conclusions/Significance LGTs unique to the genus Leishmania have been acquired after the divergence of Leishmania from the other trypanosomatids, and are evolving faster than their recipient genomes. This implies that LGT in genus Leishmania is a continuous and dynamic process contributing to species differentiation and speciation. This study also highlights the importance of carefully evaluating these dynamic genes, e.g. as LGTs have been suggested as potential drug targets.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-294607 (URN)10.1371/journal.pntd.0004326 (DOI)000372565700039 ()26730948 (PubMedID)
    Funder
    Swedish Research Council Formas, 2008-1366
    Available from: 2016-05-26 Created: 2016-05-25 Last updated: 2018-12-05Bibliographically approved
    2. Multi-targeting the folate pathway is a promising strategy against Leishmania tropica
    Open this publication in new window or tab >>Multi-targeting the folate pathway is a promising strategy against Leishmania tropica
    (English)Manuscript (preprint) (Other academic)
    National Category
    Medicinal Chemistry
    Identifiers
    urn:nbn:se:uu:diva-367381 (URN)
    Available from: 2018-12-05 Created: 2018-12-05 Last updated: 2018-12-05
    3. Prediction of anti-leishmanial drug targets using metabolite-based target fishing
    Open this publication in new window or tab >>Prediction of anti-leishmanial drug targets using metabolite-based target fishing
    (English)Manuscript (preprint) (Other academic)
    National Category
    Medicinal Chemistry
    Identifiers
    urn:nbn:se:uu:diva-368497 (URN)
    Available from: 2018-12-05 Created: 2018-12-05 Last updated: 2018-12-05
    4. Aaptamines from Haliclona and bromopyrroles from Agelas — marine sponge alkaloids with distinct modes of action against bacteria and protozoa
    Open this publication in new window or tab >>Aaptamines from Haliclona and bromopyrroles from Agelas — marine sponge alkaloids with distinct modes of action against bacteria and protozoa
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Medicinal Chemistry
    Identifiers
    urn:nbn:se:uu:diva-368498 (URN)
    Available from: 2018-12-05 Created: 2018-12-05 Last updated: 2018-12-20
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  • 345.
    Vikeved, Elisabet
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi.
    Alsmark, UCM
    Uppsala University.
    Sköld, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Prediction of anti-leishmanial drug targets using metabolite-based target fishingManuscript (preprint) (Other academic)
  • 346.
    Vikeved, Elisabet
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi.
    Sköld, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Alsmark, UCM
    Uppsala University.
    Multi-targeting the folate pathway is a promising strategy against Leishmania tropicaManuscript (preprint) (Other academic)
  • 347. Villela, Daniel
    et al.
    Leonhardt, Julia
    Patel, Neal
    Joseph, Jason
    Kirsch, Sebastian
    Hallberg, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Unger, Thomas
    Bader, Michael
    Santos, Robson A
    Sumners, Colin
    Steckelings, U Muscha
    Angiotensin type 2 receptor (AT2R) and receptor Mas: a complex liaison2015In: Clinical Science, ISSN 0143-5221, E-ISSN 1470-8736, Vol. 128, no 4, p. 227-234Article, review/survey (Refereed)
    Abstract [en]

    The angiotensin type 2 receptor (AT2R) and the receptor Mas are components of the protective arms of the renin-angiotensin system (RAS), i.e. they both mediate tissue protective and regenerative actions. The spectrum of actions of these two receptors and their signalling mechanisms display striking similarities. Moreover, in some instances, antagonists for one receptor are able to inhibit the action of agonists for the respective other receptor. These observations suggest that there may be a functional or even physical interaction of both receptors. This article discusses potential mechanisms underlying the phenomenon of blockade of angiotensin-(1-7) [Ang-(1-7)] actions by AT2R antagonists and vice versa. Such mechanisms may comprise dimerization of the receptors or dimerization-independent mechanisms such as lack of specificity of the receptor ligands used in the experiments or involvement of the Ang-(1-7) metabolite alamandine and its receptor MrgD in the observed effects. We conclude that evidence for a functional interaction of both receptors is strong, but that such an interaction may be species- and/or tissue-specific and that elucidation of the precise nature of the interaction is only at the very beginning.

  • 348.
    Wallinder, Charlotta
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Sköld, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Botros, Milad
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Guimond, Marie-Odile
    Hallberg, Mathias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Gallo-Payet, Nicole
    Karlén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Alterman, Mathias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Interconversion of Functional Activity by Minor Structural Alterations in Nonpeptide AT2 Receptor Ligands2015In: ACS Medicinal Chemistry Letters, ISSN 1948-5875, E-ISSN 1948-5875, Vol. 6, no 2, p. 178-182Article in journal (Refereed)
    Abstract [en]

    Migration of the methylene imidazole side chain in the first reported selective drug-like AT, receptor agonist C21/M024 (1) delivered the AT, receptor antagonist C38/M132 (2). We now report that the AT, receptor antagonist compound 4, a biphenyl derivative that is structurally related to 2, is transformed to the agonist 6 by migration of the isobutyl group. The importance of the relative position of the methylene imidazole and the isobutyl substituent is highlighted herein.

  • 349.
    Wallinder, Charlotta
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Drug Design and Discovery.
    Sköld, Christian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Drug Design and Discovery.
    Sundholm, Sara
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Guimond, Marie-Odile
    Univ Sherbrooke, Fac Med & Hlth Sci, Serv Endocrinol, Sherbrooke, PQ J1H 5N4, Canada.
    Yahiaoui, Samir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Lindeberg, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Gallo-Payet, Nicole
    Univ Sherbrooke, Fac Med & Hlth Sci, Serv Endocrinol, Sherbrooke, PQ J1H 5N4, Canada.
    Hallberg, Mathias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Alterman, Mathias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    High affinity rigidified AT(2) receptor ligands with indane scaffolds2019In: MedChemComm, ISSN 2040-2503, E-ISSN 2040-2511, Vol. 10, no 12, p. 2146-2160Article in journal (Refereed)
    Abstract [en]

    Rigidification of the isobutyl side chain of drug-like AT(2) receptor agonists and antagonists that are structurally related to the first reported selective AT(2) receptor agonist 1 (C21) delivered bioactive indane derivatives. Four enantiomer pairs were synthesized and the enantiomers were isolated in an optical purity >99%. The enantiomers 7a, 7b, 8a, 8b, 9a, 9b, 10a and 10b bind to the AT(2) receptor with moderate (K-i = 54-223 nM) to high affinity (K-i = 2.2-7.0 nM). The enantiomer with positive optical rotation (+) exhibited the highest affinity at the receptor. The indane derivatives 7b and 10a are among the most potent AT(2) receptor antagonists reported so far. As illustrated by the enantiomer pairs 7a/b and 10a/b, an alteration at the stereogenic center has a pronounced impact on the activation process of the AT(2) receptor, and can convert agonists to antagonists and vice versa.

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    fulltext
  • 350. Wang, Likui
    et al.
    Gao, Shijuan
    Jiang, Wei
    Luo, Cheng
    Xu, Maonian
    Bohlin, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Pharmacognosy.
    Rosendahl, Markus
    Huang, Wenlin
    Antioxidative Dietary Compounds Modulate Gene Expression Associated with Apoptosis, DNA Repair, Inhibition of Cell Proliferation and Migration2014In: International Journal of Molecular Sciences, ISSN 1422-0067, E-ISSN 1422-0067, Vol. 15, no 9, p. 16226-16245Article, review/survey (Refereed)
    Abstract [en]

    Many dietary compounds are known to have health benefits owing to their antioxidative and anti-inflammatory properties. To determine the molecular mechanism of these food-derived compounds, we analyzed their effect on various genes related to cell apoptosis, DNA damage and repair, oxidation and inflammation using in vitro cell culture assays. This review further tests the hypothesis proposed previously that downstream products of COX-2 (cyclooxygenase-2) called electrophilic oxo-derivatives induce antioxidant responsive elements (ARE), which leads to cell proliferation under antioxidative conditions. Our findings support this hypothesis and show that cell proliferation was inhibited when COX-2 was down-regulated by polyphenols and polysaccharides. Flattened macrophage morphology was also observed following the induction of cytokine production by polysaccharides extracted from viili, a traditional Nordic fermented dairy product. Coix lacryma-jobi (coix) polysaccharides were found to reduce mitochondrial membrane potential and induce caspase-3- and 9-mediated apoptosis. In contrast, polyphenols from blueberries were involved in the ultraviolet-activated p53/Gadd45/MDM2 DNA repair system by restoring the cell membrane potential. Inhibition of hypoxia-inducible factor-1 by saponin extracts of ginsenoside (Ginsen) and Gynostemma and inhibition of S100A4 by coix polysaccharides inhibited cancer cell migration and invasion. These observations suggest that antioxidants and changes in cell membrane potential are the major driving forces that transfer signals through the cell membrane into the cytosol and nucleus, triggering gene expression, changes in cell proliferation and the induction of apoptosis or DNA repair.

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