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  • 251. Shcherbakova, A.
    et al.
    Boldbaatar, Delgerbat
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Strömstedt, Adam
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Koptina, Anna
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bioassay-guided fractionation of acetonitrile extract from Evernia prinastri (L.) Ach.2014Ingår i: Phytopharm 2014, Saint-Petersburg, Russia 3-5 July 2014 / [ed] Shabanov P.D., Saint-Petersburg, Russia, 2014, Vol. 12, s. 59-60Konferensbidrag (Refereegranskat)
  • 252.
    Shcherbakova, A.
    et al.
    Volga State Tech Univ, Div Biotechnol, Yoshkar Ola, Russia.;UKB, Med Klin 3, Bonn, Germany..
    Koptina, Anna
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Ulrich-Merzenich, G.
    UKB, Med Klin 3, Bonn, Germany..
    Lichen substances sensitize the human glioblastoma cell line U87MG for the cytotoxic action of temozolomide2015Ingår i: Oncology Research and Treatment, ISSN 2296-5270, Vol. 38, s. 250-251Artikel i tidskrift (Övrigt vetenskapligt)
  • 253.
    Shcherbokova, A.
    et al.
    Volga State Tech Univ, Yoshkar Ola, Russia.;Univ Bonn, Med Clin 3, Univ Clin Ctr, Bonn, Germany..
    Koptina, Anna
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Samiento-Diaz, M.
    Univ Bonn, Med Clin 3, Univ Clin Ctr, Bonn, Germany..
    Ulrich-Merzenich, G.
    Univ Bonn, Med Clin 3, Univ Clin Ctr, Bonn, Germany..
    Pharmacological activities of lichens from Russia2015Ingår i: Planta Medica, ISSN 0032-0943, E-ISSN 1439-0221, Vol. 81, nr 16, s. 1462-1462Artikel i tidskrift (Övrigt vetenskapligt)
  • 254.
    Shwter, Abdrabuh N.
    et al.
    Univ Malaya, Dept Biomed Sci, Fac Med, Kuala Lumpur 50603, Malaysia..
    Abdullah, Nor Azizan
    Univ Malaya, Dept Pharmacol, Fac Med, Kuala Lumpur 50603, Malaysia..
    Alshawsh, Mohammed A.
    Univ Malaya, Dept Pharmacol, Fac Med, Kuala Lumpur 50603, Malaysia..
    El-Seedi, Hesham R.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi. Univ Malaya, Dept Chem, Fac Sci, Kuala Lumpur 50603, Malaysia..
    Al-Henhena, Nawal A.
    Univ Malaya, Dept Biomed Sci, Fac Med, Kuala Lumpur 50603, Malaysia..
    Khalifa, Shaden A. M.
    Karolinska Univ Hosp, Dept Expt Hematol, SE-14186 Stockholm, Sweden..
    Abdulla, Mahmood A.
    Univ Malaya, Dept Biomed Sci, Fac Med, Kuala Lumpur 50603, Malaysia..
    Chemopreventive effect of Phaleria macrocarpa on colorectal cancer aberrant crypt foci in vivo2016Ingår i: Journal of Ethnopharmacology, ISSN 0378-8741, E-ISSN 1872-7573, Vol. 193, s. 195-206Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ethnopharmacological relevance: Natural products are important ingredients for pharmaceutical applications specifically new entities for treating cancer and other diseases. Phaleria macrocarpa is native of Indonesia and considered as a prolific source of bioactive substances useful for chemoprevention. Aim of the study: To investigate the chemopreventive properties of Phaleria macrocarpa on azoxymethane (AOM)-induced aberrant crypt foci (ACF) in rats. Methods: The biological activities of the ethanol extract of P. macrocarpa fruits were evaluated both in vitro and in vivo. First the extract was investigated for its in vitro antioxidant activity by the total phenolic content and ferric reducing antioxidant power assay. Then the chemopreventive effect of P. macrocarpa was performed on AOM-induced aberrant crypt foci as colorectal carcinoma model in rats. Result: the crude ethanolic extract of P. macrocarpa has high antioxidant activity and modulated the oxidative stress as proved by the up-regulation of glutathione-s-transferase and superoxide dismutase. Immunohistochemical staining of the treated sections showed overexpression of PCNA and Bax, reduced crypt sizes and numbers, indicating the characteristic feature of apoptotic cancer cells. PCNA is a landmark of cell damage and turn-over and can be associated with clinical cancer mutation. The most potent doses were 250 mg/kg and 500 mg/kg as compared to 35 mg/kg 5-fluorouracil. Conclusion: In this sense, the potential modulation of the colorectal pathophysiological pathway by P. macrocarpa natural compounds mostly flavonoids offer a great possibility for the discovery of new leads towards the colorectal cancer.

  • 255. Siedle, Bettina
    et al.
    Gustavsson, Linda
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Johansson, Senia
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Murillo, Renato
    Castro, Victor
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Merfort, Irmgard
    The effect of sesquiterpene lactones on the release of human neutrophil elastase2003Ingår i: Biochemical Pharmacology, ISSN 0006-2952, E-ISSN 1356-1839, Vol. 65, nr 5, s. 897-903Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sesquiterpene lactones (SLs) are natural products responsible for the anti-inflammatory activity of a variety of medicinal plants, mainly from the Asteraceae family. Here, we investigated whether they also influence the process of exocytosis of pro-inflammatory enzymes, such as the human neutrophil elastase (HNE). Altogether, eight structurally different SLs from the eudesmanolide, guaianolide, pseudoguaianolide, and germacranolide type were studied. Neutrophils were isolated from fresh human blood. After pre-incubation with different concentrations of the respective SL and cytochalasin B, the exocytosis of elastase was initiated either by platelet activating factor or N-formyl-methionyl-leucyl-phenylalanine. Inhibition of HNE release was measured by p-nitroaniline formation. The SLs exhibited an inhibitory effect on elastase release from neutrophils challenged either by platelet activating factor or N-formyl-methionyl-leucyl-phenylalanine. Concentration-response curves were recorded and the IC(50) values ranged from 2 to 30 microM. Studies on isolated HNE showed that a selective direct inhibition on HNE can be excluded. Interestingly, the inhibitory activity did not correlate with the number of alpha,beta-unsaturated carbonyl functions. The structure-activity relationship and the molecular mechanism are discussed.

  • 256.
    Sikora, Per
    et al.
    Sahlgrens Univ Hosp, Lab Med Core Facil, Gothenburg, Sweden.;Publ Hlth Agcy Sweden, Dept Microbiol, Solna, Sweden..
    Andersson, Sofia
    Publ Hlth Agcy Sweden, Dept Microbiol, Solna, Sweden..
    Winiecka-Krusnell, Jadwiga
    Publ Hlth Agcy Sweden, Dept Microbiol, Solna, Sweden..
    Hallstrom, Bjorn
    Publ Hlth Agcy Sweden, Dept Microbiol, Solna, Sweden..
    Alsmark, Cecilia
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi. Natl Vet Inst, Dept Microbiol, Uppsala, Sweden..
    Troell, Karin
    Natl Vet Inst, Dept Microbiol, Uppsala, Sweden..
    Beser, Jessica
    Publ Hlth Agcy Sweden, Dept Microbiol, Solna, Sweden..
    Arrighi, Romanico B. G.
    Publ Hlth Agcy Sweden, Dept Microbiol, Solna, Sweden..
    Genomic Variation in IbA10G2 and Other Patient-Derived Cryptosporidium hominis Subtypes2017Ingår i: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 55, nr 3, s. 844-858Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In order to improve genotyping and epidemiological analysis of Cryptosporidium spp., genomic data need to be generated directly from a broad range of clinical specimens. Utilizing a robust method that we developed for the purification and generation of amplified target DNA, we present its application for the successful isolation and whole-genome sequencing of 14 different Cryptosporidium hominis patient specimens. Six isolates of subtype IbA10G2 were analyzed together with a single representative each of 8 other subtypes: IaA20R3, IaA23R3, IbA9G3, IbA13G3, IdA14, IeA11G3T3, IfA12G1, and IkA18G1. Parasite burden was measured over a range of more than 2 orders of magnitude for all samples, while the genomes were sequenced to mean depths of between 17X and 490X coverage. Sequence homologybased functional annotation identified several genes of interest, including the gene encoding Cryptosporidium oocyst wall protein 9 (COWP9), which presented a predicted loss-of-function mutation in all the sequence subtypes, except for that seen with IbA10G2, which has a sequence identical to the Cryptosporidium parvum reference Iowa II sequence. Furthermore, phylogenetic analysis showed that all the IbA10G2 genomes form a monophyletic clade in the C. hominis tree as expected and yet display some heterogeneity within the IbA10G2 subtype. The current report validates the aforementioned method for isolating and sequencing Cryptosporidium directly from clinical stool samples. In addition, the analysis demonstrates the potential in mining data generated from sequencing multiple whole genomes of Cryptosporidium from human fecal samples, while alluding to the potential for a higher degree of genotyping within Cryptosporidium epidemiology.

  • 257. Simonsen, Shane M
    et al.
    Sando, Lillian
    Ireland, David C
    Colgrave, Michelle L
    Bharathi, Rekha
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Craik, David J
    A continent of plant defense peptide diversity: cyclotides in Australian Hybanthus (Violaceae)2005Ingår i: The Plant Cell, ISSN 1040-4651, E-ISSN 1532-298X, Vol. 17, nr 11, s. 3176-3189Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cyclotides are plant-derived miniproteins that have the unusual features of a head-to-tail cyclized peptide backbone and a knotted arrangement of disulfide bonds. It had been postulated that they might be an especially large family of host defense agents, but this had not yet been tested by field data on cyclotide variation in wild plant populations. In this study, we sampled Australian Hybanthus (Violaceae) to gain an insight into the level of variation within populations, within species, and between species. A wealth of cyclotide diversity was discovered: at least 246 new cyclotides are present in the 11 species sampled, and 26 novel sequences were characterized. A new approach to the discovery of cyclotide sequences was developed based on the identification of a conserved sequence within a signal sequence in cyclotide precursors. The number of cyclotides in the Violaceae is now estimated to be >9000. Cyclotide physicochemical profiles were shown to be a useful taxonomic feature that reflected species and their morphological relationships. The novel sequences provided substantial insight into the tolerance of the cystine knot framework in cyclotides to amino acid substitutions and will facilitate protein engineering applications of this framework.

  • 258.
    Sjögren, Martin
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Dahlström, Mia
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Jonsson, Per R
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Recruiment in the field of Balanus improvisus and Mytilus edulis in response to the antifouling cyclopeptides barettin and 8,9-dihydrobarettin from the marine sponge Geodia barretti2004Ingår i: Biofouling (Print), ISSN 0892-7014, E-ISSN 1029-2454, Vol. 20, nr 6, s. 291-297Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this field investigation the two cyclopeptides, isolated from the marine sponge Geodia barretti Bowerbank (Geodiidae, Astrophorida), are shown to be very efficient in preventing recruitment of the barnacle Balanus improvisus (Cirripedia, Crustacea) and the blue mussel Mytilis edulis (Protobranchia, Lamellibranchia) when included in different marine paints. These brominated cyclopeptides, named barettin and 8,9-dihydrobarettin were incorporated in different non-toxic coatings. The substances were used in the concentrations 0.1 and 0.01% in all treatments. The most efficient paint was a SPC polymer. This paint, in combination with barettin and 8,9-dihydrobarettin, reduced the recruitment of B. improvisus by 89% (barettin, 0.1%) and by 67% (8,9-dihydrobarettin, 0.1%) as compared to control panels. For M. edulis, the reduction of recruitment was 81% with barettin (0.1%) and 72% with 8,9-dihydrobarettin (0.1%) included in the SPC paint. This indicates that the two compounds from G. barretti could provide non-toxic alternatives as additives in antifouling paints, since the heavy metal-based marine paints are to be replaced.

  • 259.
    Sjögren, Martin
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Dahlström, Mia
    Hedner, Erik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Jonsson, Per R.
    Vik, Anders
    Gundersen, Lise-Lotte
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Antifouling activity of the sponge metabolite agelasine D and synthesised analogs on Balanus improvisus.2008Ingår i: Biofouling (Print), ISSN 0892-7014, E-ISSN 1029-2454, Vol. 24, nr 4, s. 251-258Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study reports a screening study for antifouling (AF) activity of the natural compound agelasine D isolated from marine sponges of the genus Agelas and 20 synthesised analogs of agelasines and agelasimines. Agelasine D, together with two of the analogs, ie AV1003A and AKB695, displayed a strong inhibitory effect on settlement of Balanus improvisus cypris larvae. Agelasine D had an EC50 value of 0.11 mu M while the two analogs AV1033A and AKB695 had EC50 values of 0.23 and 0.3 mu M, respectively. None of these three compounds affected larval mortality as was the case with several of the analogs tested. Moreover, the effect of AV1033A and AKB695 was reversible. When cyprids after 24 h exposure to the compounds were transferred to fresh seawater, the settlement frequency compared with the controls was completely recovered. The properties of the agelasine D analogs AV1003A and AKB695 make them highly attractive candidates as AF agents in future marine coatings.

  • 260.
    Sjögren, Martin
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Johnson, Ann-Louise
    Dahlström, Mia
    Andersson, Rolf
    Bergman, Jan
    Jonsson, Per R
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Antifouling Activity of Brominated Cyclopeptides from the Marine Sponge Geodia barretti2004Ingår i: Journal of natural products (Print), ISSN 0163-3864, E-ISSN 1520-6025, Vol. 67, nr 3, s. 368-372Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, we show the potent antifouling effects of two compounds, barettin (cyclo[(6-bromo-8-entryptophan)arginine]) (1), isolated as a Z/E mixture (87/13), and 8,9-dihydrobarettin (cyclo[(6-bromotryptophan)arginine]) (2), isolated from the marine sponge Geodia barretti. The compounds were isolated guided by their ability to inhibit the settlement of cyprid larvae of the barnacle Balanusimprovisus, and their structures were determined by means of mass spectrometry, NMR, and quantitative amino acid analysis. The activities of these brominated diketopiperazine-like cyclic dipeptides are in the range of antifouling agents in use today, as shown by their EC(50) values of 0.9 and 7.9 microM, respectively. However, contrary to today's antifouling agents, the effects of barettin and 8,9-dihydrobarettin are nontoxic and reversible. A small set of synthetic analogues, including l-arginine, l-tryptophan, 5-bromo-d,l-tryptophan, 6-bromo-d,l-tryptophan, and 6-fluoro-d,l-tryptophan, were tested for possible structure-activity relationships. None of these compounds showed any effect at a concentration of 10 microM. We hypothesize that the isolated compounds are part of the sponge's chemical defense to deter fouling organisms. This theory is supported by the fact that barettin is found in water exposed to living specimens of G. barretti in concentrations that completely inhibit barnacles from settling.

  • 261.
    Sjögren, Martin
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Johnson, Ann-Louise
    Dahlström, Mia
    Andersson, Rolf
    Bergman, Jan
    Jonsson, Per R
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Antifouling activity of brominated cyclopeptides from the marine sponge Geodia barretti2004Ingår i: Journal of natural products (Print), ISSN 0163-3864, E-ISSN 1520-6025, Vol. 67, nr 3, s. 368-372Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, we show the potent antifouling effects of two compounds, barettin (cyclo[(6-bromo-8-entryptophan)arginine]) (1), isolated as a Z/E mixture (87/13), and 8,9-dihydrobarettin (cyclo[(6-bromotryptophan)arginine]) (2), isolated from the marine sponge Geodia barretti. The compounds were isolated guided by their ability to inhibit the settlement of cyprid larvae of the barnacle Balanusimprovisus, and their structures were determined by means of mass spectrometry, NMR, and quantitative amino acid analysis. The activities of these brominated diketopiperazine-like cyclic dipeptides are in the range of antifouling agents in use today, as shown by their EC(50) values of 0.9 and 7.9 microM, respectively. However, contrary to today's antifouling agents, the effects of barettin and 8,9-dihydrobarettin are nontoxic and reversible. A small set of synthetic analogues, including l-arginine, l-tryptophan, 5-bromo-d,l-tryptophan, 6-bromo-d,l-tryptophan, and 6-fluoro-d,l-tryptophan, were tested for possible structure-activity relationships. None of these compounds showed any effect at a concentration of 10 microM. We hypothesize that the isolated compounds are part of the sponge's chemical defense to deter fouling organisms. This theory is supported by the fact that barettin is found in water exposed to living specimens of G. barretti in concentrations that completely inhibit barnacles from settling.

  • 262.
    Sjögren, Martin
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi.
    Johnson, Ann-Louise
    Hedner, Erik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Dahlström, Mia
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi.
    Shirani, Hamid
    Bergman, Jan
    Jonsson, Per R.
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi.
    Antifouling activity of synthesized peptide analogs of the sponge metabolite barettin2006Ingår i: Peptides, ISSN 0196-9781, E-ISSN 1873-5169, Vol. 27, nr 9, s. 2058-2064Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Barettin (cyclo [(6-bromo-8-en-tryptophan) arginine]), a diketopiperazine isolated from the marine sponge Geodia barretti, is a potent inhibitor of barnacle larvae settlement with an EC50-value of 0.9 mu M. In the present study, 14 analogs of barettin and its structural congener dipodazine were synthezised and tested for their ability to inhibit larval settlement. Two of the analogs have an intact barettin skeleton. The remaining analogs have a dipodazine skeleton (a diketopiperazine where arginine is replaced with glycine). Six of the tested synthetic analogs displayed significant settlement inhibition with the most potent inhibitor being benzo[g]dipodazine, which displayed even stronger activity than barettin (EC50-value 0.034 mu M). The effect of benzo[g]dipodazine was also shown to be readily reversible, when cyprids were transferred to filtered seawater (FSW).

  • 263.
    Sjögren, Martin
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Jonsson, Per R.
    Dahlström, Mia
    Lundälv, Tomas
    Burman, Robert
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Two Brominated Cyclic Dipeptides Released by the Coldwater Marine Sponge Geodia barretti Act in Synergy As Chemical Defense2011Ingår i: Journal of natural products (Print), ISSN 0163-3864, E-ISSN 1520-6025, Vol. 74, nr 3, s. 449-454Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The current work shows that two structurally similar cyclodipeptides, barettin (1) and 8,9-dihydrobarettin (2), produced by the coldwater marine sponge Geodia barretti Bowerbank act in synergy to deter larvae of surface settlers and may also be involved in defense against grazers. Previously, 1 and 2 were demonstrated to bind specifically to serotonergic 5-HT receptors. It may be suggested that chemical defense in G. barretti involves a synergistic action where one of the molecular targets is a 5-HT receptor. A mixture of 1 and 2 lowered the EC50 of larval settlement as compared to the calculated theoretical additive effect of the two compounds. Moreover, an in situ sampling at 120 m depth using a remotely operated vehicle revealed that the sponge releases these two compounds to the ambient water. Thus, it is suggested that the synergistic action of 1 and 2 may benefit the sponge by reducing the expenditure of continuous production and release of its chemical defense substances. Furthermore, a synergistic action between structurally closely related compounds produced by the same bioenzymatic machinery ought to be the most energy effective for the organism and, thus, is more common than synergy between structurally indistinct compounds.

  • 264.
    Slazak, Blazej
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi. Jagiellonian Univ, Inst Bot, Dept Plant Cytol & Embryol, PL-30387 Krakow, Poland.;Polish Acad Sci, W Szafer Ist Bot, PL-31512 Krakow, Poland..
    Jacobsson, Erik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Kuta, Elzbieta
    Jagiellonian Univ, Inst Bot, Dept Plant Cytol & Embryol, PL-30387 Krakow, Poland..
    Goransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Exogenous plant hormones and cyclotide expression in Viola uliginosa (Violaceae)2015Ingår i: Phytochemistry, ISSN 0031-9422, E-ISSN 1873-3700, Vol. 117, s. 527-536Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Plants from Violaceae produce cyclotides, peptides characterized by a circular peptide backbone and a cystine knot. This signature motif gives stability that can harness a wide spectrum of biological activities, with implications in plant defense and with applications in medicine and biotechnology. In the current work, cyclotide expressing in vitro cultures were established from Viola uliginosa. These cultures are useful models for studying biosynthesis of cyclotides and can also be used in their production. The cyclotide expression pattern is shown to be dependent on exogenous plant growth regulators, both on peptide and gene expression levels. The highest yields of cyclotides were obtained on media containing only a cytokinin and were correlated with storage material accumulation. Exposure to auxins decreased cyclotide production and caused shifting of the biosynthesis pattern to root specific cyclotides. The response to stimuli in terms of cyclotide expression pattern appears to be developmental, and related to polar auxin transportation and the auxin/cytokinin ratio regulating tissue differentiation. By the use of whole transcriptome shotgun sequencing (WTSS) and peptidomics, 20 cyclotide sequences from V. uliginosa (including 12 new) and 12 complete precursor proteins could be identified. The most abundant cyclotides were cycloviolacin O3 (CyO3), CyO8 and CyO13. A suspension culture was obtained that grew exponentially with a doubling time of approximately 3 days. After ten days of growth, the culture provided a yield of more than 4 mg CyO13 per gram dry mass.

  • 265.
    Slazak, Blazej
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi. 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 universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    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 universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Immunolocalization of cyclotides in plant cells, tissues and organ supports their role in host defense2016Ingår i: Planta, ISSN 0032-0935, E-ISSN 1432-2048, Vol. 244, nr 5, s. 1029-1040Artikel i tidskrift (Refereegranskat)
    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.

  • 266. Slazak, Blazej
    et al.
    Sliwinska, Elwira
    Saluga, Marta
    Ronikier, Michal
    Bujak, Justyna
    Slomka, Aneta
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Kuta, Elzbieta
    Micropropagation of Viola uliginosa (Violaceae) for endangered species conservation and for somaclonal variation-enhanced cyclotide biosynthesis2015Ingår i: Plant Cell Tissue and Organ Culture, ISSN 0167-6857, E-ISSN 1573-5044, Vol. 120, nr 1, s. 179-190Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Viola uliginosa Besser is a European violet having its main distribution range in the Baltic Sea region. Today it is considered endangered and threatened. Species of Violaceae from different genera and sections are known to produce cyclotides, cyclic polypeptides of much interest due to their medicinal properties and chemical structure. The present study introduced a rare species of violet (V. uliginosa) to in vitro culture for biodiversity protection and as a model for cyclotide biosynthesis research in the Violaceae. Leaf and petiole fragments were cultured on MS medium solidified with agar and supplemented with different concentrations of plant growth regulators: TDZ, KIN and 2,4-D. Direct and indirect (via callus) organogenesis was induced on MS supplemented with TDZ (0.5 or 1 mg l(-1)) or with equal concentrations (2 mg l(-1)) of KIN and 2,4-D, followed by callus transfer on 1 mg l(-1) TDZ. Shoots were rooted on MS with 2 % sucrose and 0.5 mg l(-1) IBA and acclimatized. AFLP marker polymorphism was low but flow cytometry revealed that a large share of the obtained regenerants were tetraploid (2C = 4x = 2.7-2.8 pg), unlike the maternal diploid plants (2C = 2x = 1.4 pg). Eleven different cyclotides were distinguished in the aerial parts of maternal plants. Cyclotide production was significantly higher in tetraploid than in diploid plants regenerated in vitro.

  • 267. Stenholm, A.
    et al.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bioassay-guided Supercritical Fluid Extraction of Cyclooxygenase-2 Inhibiting Substances in Plantago major L.2013Ingår i: Phytochemical Analysis, ISSN 0958-0344, E-ISSN 1099-1565, Vol. 24, nr 2, s. 176-183Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Introduction - Selective extraction of plant materials is advantageous for obtaining extracts enriched with desired constituents, thereby reducing the need for subsequent chromatography purification. Such compounds include three cyclooxygenase-2 (COX-2) inhibitory substances in Plantago major L. targeted in this investigation: alpha-linolenic acid (alpha-LNA) (18:3 omega-3) and the triterpenic acids ursolic acid and oleanolic acid. Objective - To investigate the scope for tuning the selectivity of supercritical fluid extraction (SFE) using bioassay guidance, and Soxhlet extraction with dichloromethane as solvent as a reference technique, to optimise yields of these substances. Method - Extraction parameters were varied to optimise extracts' COX-2/COX-1 inhibitory effect ratios. The crude extracts were purified initially using a solid phase extraction (SPE) clean-up procedure and the target compounds were identified with GC-MS, LC-ESI-MS and LC-ESI-MS2 using GC-FID for quantification. Results - alpha-LNA was preferentially extracted in dynamic mode using unmodified carbon dioxide at 40 degrees C and 172 bar, at a 0.04% (w/w) yield with a COX-2/COX-1 inhibitory effect ratio of 1.5. Ursolic and oleanolic acids were dynamically extracted at 0.25% and 0.06% yields, respectively, with no traces of (alpha-LNA) and a COX-2/COX-1-inhibitory effect ratio of 1.1 using 10% (v/v) ethanol as polar modifier at 75 degrees C and 483 bar. The Soxhlet extracts had ursolic acid, oleanolic acid and alpha LNA yields up to 1.36%, 0.34% and 0.15%, respectively, with a COX-2/COX-1 inhibitory effect ratio of 1.2. Conclusion - The target substances can be extracted selectively by bioassay guided optimisation of SFE conditions.

  • 268.
    Sterby, Mia
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Dissecting the Structure-Activity Relationship of Hairpinin, a Plant Derived Antimicrobial Peptide2014Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Antibiotic resistance is a growing health issue that necessitates development of alternative drugs with antimicrobial properties. Antimicrobial peptides are a promising group of compounds in this respect and are used by all varieties of living organisms to defend against invading or competing organisms. Hairpinin is an antimicrobial peptide isolated from Echinochloa crus-galli that has previously been found to have antifungal activity. In this study, truncated variants of hairpinin were synthesized and their antifungal activity tested against Candida albicans, Aspergillus fumigatus, and Saccharomyces cerevisiae to identify the minimum structural element of hairpinin required for maintained activity. Hairpinin was active against all three fungi with a minimum inhibitory concentration ranging between 0.6 μM - 5 μM depending on strain and growth media. Two truncated versions were synthesized in this study by solid-phase peptide synthesis, also resulting in a dimer of one of the derivatives, and their antifungal activity was assessed together with four other truncated peptides previously synthesized. The findings indicated that hairpinins C-terminal end together with an inflexible central part stabilized by at least one disulfide bond was vital for activity. The mechanism of action in which hairpinin inhibits fungi was examined by liposome leakage assay of Escherichia coli and Saccharomyces cerevisiae model membranes. It was concluded that the mechanism of action did not involve membrane disruption, a common mechanism among similar antimicrobial peptides. Although hairpinin displayed potent antifungal activity, it was found to be proteolytically unstable in serum. To improve hairpinins value in pharmaceutical context stability has to be improved while preserving the important structural elements.

  • 269.
    Strand, Malin
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi. Swedish Agricultural University.
    Hedström, Martin
    Seth, Henrik
    McEvoy, Eric G
    Jacobsson, Erik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Andersson, Håkan S
    Sundberg, Per
    The Bacterial (Vibrio alginolyticus) Production of Tetrodotoxin in the Ribbon Worm Lineus longissimus-Just a False Positive?2016Ingår i: Marine Drugs, ISSN 1660-3397, E-ISSN 1660-3397, Vol. 14, nr 4, artikel-id 63Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We test previous claims that the bacteria Vibrio alginolyticus produces tetrodotoxin (TTX) when living in symbiosis with the nemertean Lineus longissimus by a setup with bacteria cultivation for TTX production. Toxicity experiments on the shore crab, Carcinus maenas, demonstrated the presence of a paralytic toxin, but evidence from LC-MS and electrophysiological measurements of voltage-gated sodium channel-dependent nerve conductance in male Wistar rat tissue showed conclusively that this effect did not originate from TTX. However, a compound of similar molecular weight was found, albeit apparently non-toxic, and with different LC retention time and MS/MS fragmentation pattern than those of TTX. We conclude that C. maenas paralysis and death likely emanate from a compound <5 kDa, and via a different mechanism of action than that of TTX. The similarity in mass between TTX and the Vibrio-produced low-molecular-weight, non-toxic compound invokes that thorough analysis is required when assessing TTX production. Based on our findings, we suggest that re-examination of some published claims of TTX production may be warranted.

  • 270.
    Strese, Ake
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Backlund, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Alsmark, Cecilia
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    A recently transferred cluster of bacterial genes in Trichomonas vaginalis - lateral gene transfer and the fate of acquired genes2014Ingår i: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 14, s. 119-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Lateral Gene Transfer (LGT) has recently gained recognition as an important contributor to some eukaryote proteomes, but the mechanisms of acquisition and fixation in eukaryotic genomes are still uncertain. A previously defined norm for LGTs in microbial eukaryotes states that the majority are genes involved in metabolism, the LGTs are typically localized one by one, surrounded by vertically inherited genes on the chromosome, and phylogenetics shows that a broad collection of bacterial lineages have contributed to the transferome. Results: A unique 34 kbp long fragment with 27 clustered genes (TvLF) of prokaryote origin was identified in the sequenced genome of the protozoan parasite Trichomonas vaginalis. Using a PCR based approach we confirmed the presence of the orthologous fragment in four additional T. vaginalis strains. Detailed sequence analyses unambiguously suggest that TvLF is the result of one single, recent LGT event. The proposed donor is a close relative to the firmicute bacterium Peptoniphilus harei. High nucleotide sequence similarity between T. vaginalis strains, as well as to P. harei, and the absence of homologs in other Trichomonas species, suggests that the transfer event took place after the radiation of the genus Trichomonas. Some genes have undergone pseudogenization and degradation, indicating that they may not be retained in the future. Functional annotations reveal that genes involved in informational processes are particularly prone to degradation. Conclusions: We conclude that, although the majority of eukaryote LGTs are single gene occurrences, they may be acquired in clusters of several genes that are subsequently cleansed of evolutionarily less advantageous genes.

  • 271.
    Strömstedt, Adam A.
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Felth, Jenny
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bioassays in Natural Product Research: Strategies and Methods in the Search for Anti-inflammatory and Antimicrobial Activity2014Ingår i: Phytochemical Analysis, ISSN 0958-0344, E-ISSN 1099-1565, Vol. 25, nr 1, s. 13-28Artikel, forskningsöversikt (Refereegranskat)
    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.

  • 272.
    Strömstedt, Adam A.
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Kristiansen, Per Eugen
    Univ Oslo, Dept Mol Biosci, Box 1041, N-0316 Oslo, Norway.
    Gunasekera, Sunithi
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Grob, Nathalie
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Skjeldal, Lars
    Norwegian Univ Life Sci, Dept Chem Biochem & Food Sci, N-1432 As, Norway.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Selective membrane disruption by the cyclotide kalata B7: complex ions and essential functional groups in the phosphatidylethanolamine binding pocket2016Ingår i: Biochimica et Biophysica Acta, ISSN 0006-3002, E-ISSN 1878-2434, Vol. 1858, nr 6, s. 1317-1327Artikel i tidskrift (Refereegranskat)
    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.

  • 273.
    Strömstedt, Adam A.
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Park, Sungkyu
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Burman, Robert
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bactericidal activity of cyclotides where phosphatidylethanolamine-lipid selectivity determines antimicrobial spectra2017Ingår i: Biochimica et Biophysica Acta - Biomembranes, ISSN 0005-2736, E-ISSN 1879-2642, Vol. 1859, nr 10, s. 1986-2000Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cyclotides are a family of plant peptides characterized by a cystine knot embedded in a macrocyclic backbone. They bind to and disrupt phospholipid membranes, which explain their lytic activity on cells. In this study, we expose the full antibacterial potency of cyclotides by avoiding its inhibition by rich growth media assay conditions. For that purpose a two-step microdilution assay protocol was developed, using non-growing conditions during initial peptide incubation. A diverse set of cyclotides was tested for antibacterial and antifungal activity, and the results show that most cyclotides are active under these conditions, especially against Gram-negative bacteria. Activity was observed at sub-micromolar concentrations for three of the cyclotides tested, surpassing that of the control peptides LL-37 and melittin. Noteworthy, two anionic cyclotides were active on Pseudomonas aeruginosa at low micromolar concentrations. Broad-spectrum activity was pronounced among cycloviolacin cyclotides, which included activity on Staphylococcus aureus and Candida albicans. The factors influencing their bactericidal spectrum were revealed by correlating antimicrobial activity with membrane permeabilization on various liposome systems and with the physiochemical properties of the cyclotides. Whereas general electrostatic and hydrophobic parameters are more important for broad-spectrum cyclotides; a phospholipid-specific mechanism of membrane permeabilization, through interaction with phosphatidylethanolamine-lipids, is essential for cyclotides active primarily on Gram-negative bacteria.

  • 274.
    Strömstedt, Adam
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Park, Sungkyu
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Burman, Robert
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Exposing the true bactericidal potency of cyclotides: explained by lipid selectivity, structural characteristics and correlating antimicrobial activitiesManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Cyclotides are a family of plant peptides characterized by a cystine knot embedded in a macrocyclic backbone. They bind to and disrupt phospholipid membranes, which explain their activity against eukaryotic cells and enveloped viruses. In the current study, we show that potent antibacterial activity is frequent among cyclotides as long as the activity inhibiting presence of rich growth media is avoided. For that purpose a modified microdilution assay protocol was developed. This, the largest and most diverse set of cyclotides to be tested for antibacterial and antifungal activity, show that most cyclotides are active in this respect, especially against Gram-negative bacteria. Activity was observed at sub-micromolar concentrations for three of the cyclotides surpassing that of the potent control peptides melittin and LL-37. Noteworthy, two net anionic cyclotides were active on Pseudomonas aeruginosa at low micromolar concentrations. Activity against Staphylococcus aureus or Candida albicans was lower and less frequent. Permeabilizing activity on liposomes of various compositions was compared with effects on bacteria, Candida and lymphoma cells to which physiochemical properties of the cyclotides could be assigned. Analysis of quantitative structure-activity relationship found correlations between molecular patterns, phospholipid specificity and antimicrobial activity. Although certain bracelet cyclotides, with broad-spectrum activity, relied more on electrostatic and hydrophobic parameters for their bioactivity, those with primarily Gram-negative activity, in particular against P. aeruginosa, were achieving membrane binding and disruption in a phospholipid specific manner, namely a high affinity for phosphatidylethanolamine (PE). We conclude that the high PE-selectivity is linked to the potency of antibacterial activity.

  • 275.
    Svahn, K. Stefan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Goransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Strömstedt, Adam A.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    El-Seedi, Hesham
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Larsson, D. G. J.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi.
    Olsen, Björn
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi.
    Chryssanthou, E.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi.
    The search for new antibiotic substances from filamentous fungi2012Ingår i: Planta Medica, ISSN 0032-0943, E-ISSN 1439-0221, Vol. 78, nr 11, s. 1162-1162Artikel i tidskrift (Övrigt vetenskapligt)
  • 276.
    Svahn, Stefan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Analysis of Secondary Metabolites from Aspergillus fumigatus and Penicillium nalgiovense: Antimicrobial Compounds from Filamentous Fungi Isolated from Extreme Environments2015Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    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.

    Delarbeten
    1. Antimicrobial activity of filamentous fungi isolated from highly antibiotic-contaminated river sediment
    Öppna denna publikation i ny flik eller fönster >>Antimicrobial activity of filamentous fungi isolated from highly antibiotic-contaminated river sediment
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    2012 (Engelska)Ingår i: Infection ecology & epidemiology, ISSN 2000-8686, Vol. 2, s. 11591-Artikel i tidskrift (Refereegranskat) 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

    Nyckelord
    secondary metabolites, Aspergillus, gliotoxin
    Nationell ämneskategori
    Mikrobiologi
    Forskningsämne
    Farmakognosi
    Identifikatorer
    urn:nbn:se:uu:diva-188192 (URN)10.3402/iee.v2i0.11591 (DOI)
    Forskningsfinansiär
    Vinnova
    Tillgänglig från: 2012-12-13 Skapad: 2012-12-13 Senast uppdaterad: 2015-03-11Bibliografiskt granskad
    2. Penicillium nalgiovense Laxa isolated from Antarctica is a new source of the antifungal metabolite amphotericin B
    Öppna denna publikation i ny flik eller fönster >>Penicillium nalgiovense Laxa isolated from Antarctica is a new source of the antifungal metabolite amphotericin B
    Visa övriga...
    2015 (Engelska)Ingår i: Fungal biology and biothechnology, Vol. 2, nr 1Artikel i tidskrift (Refereegranskat) 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.

    Nyckelord
    Amphotericin B, Penicillium nalgiovense Laxa, Antarctica
    Nationell ämneskategori
    Läkemedelskemi
    Forskningsämne
    Farmakognosi
    Identifikatorer
    urn:nbn:se:uu:diva-242609 (URN)10.1186/s40694-014-0011-x (DOI)
    Tillgänglig från: 2015-01-28 Skapad: 2015-01-28 Senast uppdaterad: 2018-01-11Bibliografiskt granskad
    3. Induction of Gliotoxin Secretion in Aspergillus fumigatus by Bacteria-Associated Molecules
    Öppna denna publikation i ny flik eller fönster >>Induction of Gliotoxin Secretion in Aspergillus fumigatus by Bacteria-Associated Molecules
    Visa övriga...
    2014 (Engelska)Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, nr 4, s. e93685-Artikel i tidskrift (Refereegranskat) 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.

    Nationell ämneskategori
    Medicin och hälsovetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-224740 (URN)10.1371/journal.pone.0093685 (DOI)000334107500056 ()
    Tillgänglig från: 2014-05-21 Skapad: 2014-05-19 Senast uppdaterad: 2017-12-05Bibliografiskt granskad
    4. Bis(methyl)gliotoxin and gliotoxin in bronchoalveolar lavage fluids are not suitable markers for invasive aspergillosis
    Öppna denna publikation i ny flik eller fönster >>Bis(methyl)gliotoxin and gliotoxin in bronchoalveolar lavage fluids are not suitable markers for invasive aspergillosis
    Visa övriga...
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    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. 

    Nyckelord
    Invasive aspergillosis, gliotoxin, bis(methyl)gliotoxin, Aspergillus fumigatus, diagnosis
    Nationell ämneskategori
    Läkemedelskemi
    Forskningsämne
    Farmakognosi
    Identifikatorer
    urn:nbn:se:uu:diva-242610 (URN)
    Tillgänglig från: 2015-01-28 Skapad: 2015-01-28 Senast uppdaterad: 2018-01-11Bibliografiskt granskad
  • 277.
    Svahn, Stefan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi. Uppsala Universitet.
    Chryssanthou, Erja
    Olsen, Björn
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Penicillium nalgiovense Laxa isolated from Antarctica is a new source of the antifungal metabolite amphotericin B2015Ingår i: Fungal biology and biothechnology, Vol. 2, nr 1Artikel i tidskrift (Refereegranskat)
    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.

  • 278.
    Svahn, Stefan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Chryssanthou, Erja
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Janson, Christer
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Lungmedicin och allergologi.
    Olsen, Björn
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk mikrobiologi och infektionsmedicin.
    Bis(methyl)gliotoxin and gliotoxin in bronchoalveolar lavage fluids are not suitable markers for invasive aspergillosisManuskript (preprint) (Övrigt vetenskapligt)
    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. 

  • 279.
    Svahn, Stefan
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    El-Seedi, Hesham
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Larsson, Joakim
    Olsen, Björn
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar.
    Chryssanthou, Erja
    Antimicrobial activity of filamentous fungi isolated from highly antibiotic-contaminated river sediment2012Ingår i: Infection ecology & epidemiology, ISSN 2000-8686, Vol. 2, s. 11591-Artikel i tidskrift (Refereegranskat)
    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

  • 280.
    Svahn, Stefan K.
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Chryssanthou, Erja
    Olsen, Björn
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar.
    Sjölin, Jan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar.
    Stromstedt, Adam A.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Induction of Gliotoxin Secretion in Aspergillus fumigatus by Bacteria-Associated Molecules2014Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, nr 4, s. e93685-Artikel i tidskrift (Refereegranskat)
    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.

  • 281.
    Svangård, Erika
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Burman, Robert
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Gunasekera, Sunithi
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Lövborg, Henrik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk farmakologi.
    Gullbo, Joachim
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk farmakologi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Mechanism of action of cytotoxic cyclotides: cycloviolacin O2 disrupts lipid membranes2007Ingår i: Journal of natural products (Print), ISSN 0163-3864, E-ISSN 1520-6025, Vol. 70, nr 4, s. 643-647Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In recent years, the cyclotides have emerged as the largest family of naturally cyclized proteins. Cyclotides display potent cytotoxic activity that varies with the structure of the proteins, and combined with their unique structure, they represent novel cytotoxic agents. However, their mechanism of action is yet unknown. In this work we show that disruption of cell membranes plays a crucial role in the cytotoxic effect of the cyclotide cycloviolacin O2 (1), which has been isolated from Viola odorata. Cell viability and morphology studies on the human lymphoma cell line U-937 GTB showed that cells exposed to 1 displayed disintegrated cell membranes within 5 min. Functional studies on calcein-loaded HeLa cells and on liposomes showed rapid concentration-dependent release of their respective internal contents. The present results show that cyclotides have specific membrane-disrupting activity.

  • 282.
    Svangård, Erika
    et al.
    Uppsala universitet, Medicinska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Hocaoglu, Zozan
    Gullbo, Joachim
    Uppsala universitet, Medicinska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Larsson, Rolf
    Uppsala universitet, Medicinska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Claeson, Per
    Uppsala universitet, Medicinska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bohlin, Lars
    Uppsala universitet, Medicinska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Cytotoxic cyclotides from Viola tricolor2004Ingår i: Journal of natural products (Print), ISSN 0163-3864, E-ISSN 1520-6025, Vol. 67, nr 2, s. 144-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A crude fraction of Viola tricolor rich in small lipophilic proteins was prepared and subjected to fractionation guided by bioactivity, using RP-HPLC and a fluorometric cytotoxicity assay. Two human cancer cell lines, U-937 GTB (lymphoma) and RPMI-8226/s (myeloma), were used in this study. The most potent compounds isolated, that is, the compounds showing the lowest IC(50) values, were shown to be three small proteins: vitri A (IC(50) = 0.6 microM and IC(50) = 1 microM, respectively), varv A (IC(50) = 6 microM and IC(50) = 3 microM, respectively), and varv E (IC(50) = 4 microM in both cell lines). Their sequences, determined by automated Edman degradation, quantitative amino acid analysis, and mass spectrometry, were cyclo-GESCVWIPCITSAIGCSCKSKVCYRNGIPC (vitri A), cyclo-GETCVGGTCNTPGCSCSWPVCTRNGLPVC (varv A), and cyclo-GETCVGGTCNTPGCSCSWPVCTRNGLPIC (varv E), of which vitri A is described for the first time. Each forms a head-to-tail cyclic backbone, with six cysteine residues being involved in three disulfide bonds, characteristic of the family of small proteins called the cyclotides. This is the first report on cyclotides from the species V. tricolor and the first report on the sequence of the cytotoxic cyclotide vitri A.

  • 283.
    Svangård, Erika
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Smith, Derek
    Verma, Chandra
    Backlund, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Bohlin, Lars
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Claeson, Per
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Primary and 3-D modelled structures of two cyclotides from Viola odorata2003Ingår i: Phytochemistry, ISSN 0031-9422, E-ISSN 1873-3700, Vol. 64, nr 1, s. 135-142Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Two polypeptides named vodo M and vodo N, both of 29 amino acids, have been isolated from Viola odorata L. (Violaceae) using ion exchange chromatography and reversed phase HPLC. The sequences were determined by automated Edman degradation, quantitative amino acid analysis, and mass spectrometry (MS). Using MS, it was established that vodo M (cyclo-SWPVCTRNGAPICGESCFTGKCYTVQCSC) and vodo N (cyclo-SWPVCYRNGLPVCGETCTLGKCYTAGCSC) form a head-to-tail cyclic backbone and that six cysteine residues are involved in three disulphide bonds. Their origin, sequences, and cyclic nature suggest that these peptides belong to the family of cyclic plant peptides, called cyclotides. The three-dimensional structures of vodo M and vodo N were modelled by homology, using the experimentally determined structure of the cyclotide kalata B1 as the template. The images of vodo M and vodo N show amphipathic structures with considerable surface hydrophobicity for a protein modelled in a polar environment.

  • 284. Swenson, Ulf
    et al.
    Backlund, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    McLoughlin, Stephen
    Hill, Robert S.
    Nothofagus biogeography revisited with special emphasis on the enigmatic distribution of subgenus Brassospora in New Caledonia2001Ingår i: Cladistics, ISSN 0748-3007, E-ISSN 1096-0031, Vol. 17, nr 1, s. 28-47Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Dispersals versus vicariance events and the presence of subgenus Brassospora in New Caledonia are two riddles of Nothofagus biogeography, a genus also distributed in New Guinea, New Zealand, South America, Southeast Australia, and Tasmania, Within a cladistic framework using the software COMPONENT 2.0, we demonstrate that most parsimonious area cladograms (areagrams) sensu cladistic biogeography need not always be the most plausible explanation nor reflect alternative geological hypotheses, The most parsimonious Nothofagus history sensu historical biogeography is reconstructed where a minimum of dispersed taxa is hypothesized and vicariance events are identified. A fully resolved well-established Nothofagus phylogeny was reconciled with three geological hypotheses (geograms) of East Gondwana break-up: (a) the conventional view (b) an Australian-New Caledonian relationship, and (c) a biotic interchange between New Guinea and New Caledonia. Fossils determined to subgenus were optimized to the predicted lineages in the reconciled tree. Due to extensive extinctions, a maximum of three vicariance events are inferred, all being basal in the subgenera, an indication of subgeneric diversification prior to the break-up of Gondwana. Two taxa, N. gunnii and N. menziesii, are hypothesized as being long-distance dispersed, The most parsimonious solution suggests a close relationship between New Guinea and New Caledonia, supporting a Brassospora colonization route, but this hypothesis fails to predict numerous extinct lineages observed in the fossil record and thus must be rejected. The traditional break-up sequence of Gondwana is not the most parsimonious solution, indicating one incongruent node, but causes no overall incongruence with the fossil record, Considering all parameters, the occurrence of Brassospora in New Caledonia is most parsimoniously explained as a single colonization event from New Zealand where the subgenus subsequently went extinct in the Pliocene.

  • 285. Taylor, Thomas C
    et al.
    Backlund, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Björhall, Karin
    Spreitzer, Robert J.
    Andersson, Inger
    First crystal structure of Rubisco from a green alga, Chlamydomonas reinhardtii2001Ingår i: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 276, nr 51, s. 48159-48164Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The crystal structure of Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase) from the unicellular green alga, Chlamydomonas reinhardtii has been determined to 1.4 Angstrom resolution. Overall, the structure shows high similarity to the previously determined structures of L8S8 Rubisco enzymes. The largest difference is found in the loop between beta strands A and B of the small subunit (betaA-betaB loop), which is longer by six amino acid residues than the corresponding region in Rubisco from Spinacia. Mutations of residues in the betaA-betaB loop have been shown to affect holoenzyme stability and catalytic properties. The information contained in the Chlamydomonas structure enables a more reliable analysis of the effect of these mutations. No electron density was observed for the last 13 residues of the small subunit, which are assumed to be disordered in the crystal. Because of the high resolution of the data, some posttranslational modifications are unambiguously apparent in the structure. These include cysteine and N-terminal methylations and proline 4-hydroxylations.

  • 286.
    Thell, Kathrin
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Hellinger, Roland
    Sahin, Emine
    Michenthaler, Paul
    Gold-Binder, Markus
    Haider, Thomas
    Kuttke, Mario
    Liutkevičiūtė, Zita
    Göransson, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Gründemann, Carsten
    Schabbauer, Gernot
    Gruber, Christian W
    Oral activity of a nature-derived cyclic peptide for the treatment of multiple sclerosis.2016Ingår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 113, nr 15, s. 3960-3965Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multiple sclerosis (MS) is the most common autoimmune disease affecting the central nervous system. It is characterized by auto-reactive T cells that induce demyelination and neuronal degradation. Treatment options are still limited and several MS medications need to be administered by parenteral application but are modestly effective. Oral active drugs such as fingolimod have been weighed down by safety concerns. Consequently, there is a demand for novel, especially orally active therapeutics. Nature offers an abundance of compounds for drug discovery. Recently, the circular plant peptide kalata B1 was shown to silence T-cell proliferation in vitro in an IL-2-dependent mechanism. Owing to this promising effect, we aimed to determine in vivo activity of the cyclotide [T20K]kalata B1 using the MS mouse model experimental autoimmune encephalomyelitis (EAE). Treatment of mice with the cyclotide resulted in a significant delay and diminished symptoms of EAE by oral administration. Cyclotide application substantially impeded disease progression and did not exhibit adverse effects. Inhibition of lymphocyte proliferation and the reduction of proinflammatory cytokines, in particular IL-2, distinguish the cyclotide from other marketed drugs. Considering their stable structural topology and oral activity, cyclotides are candidates as peptide therapeutics for pharmaceutical drug development for treatment of T-cell-mediated disorders.