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Itsenko, Oleksiy
Publications (7 of 7) Show all publications
Lavén, M., Itsenko, O. & Markides, K. (2006). Determination of metabolic stability of positron emission tomography tracers by LC-MS/MS: An example in WAY-100635 and two analogues. J. of Pharmaceutical and Biomedical Analysis (40), 943-951
Open this publication in new window or tab >>Determination of metabolic stability of positron emission tomography tracers by LC-MS/MS: An example in WAY-100635 and two analogues
2006 (English)In: J. of Pharmaceutical and Biomedical Analysis, no 40, p. 943-951Article in journal (Refereed) Published
Keywords
Positron emission tomography, LC-MS, Metabolic stability, Metabolism, WAY-100635
Identifiers
urn:nbn:se:uu:diva-83362 (URN)doi:10.1016/j.jpba2005.08.010 (DOI)
Available from: 2006-11-01 Created: 2006-11-01 Last updated: 2011-01-11
Itsenko, O., Kihlberg, T. & Långström, B. (2006). Labeling of aliphatic carboxylic acids using [11C]carbon monoxide. Nature Protocols, 1(2), 798-802
Open this publication in new window or tab >>Labeling of aliphatic carboxylic acids using [11C]carbon monoxide
2006 (English)In: Nature Protocols, ISSN 1754-2189, Vol. 1, no 2, p. 798-802Article in journal (Refereed) Published
Abstract [en]

Here we present a protocol for labeling aliphatic carboxylic acids with the positron-emitting radionuclide 11C (t1/2 = 20.4 min) at the carboxyl position using [11C]carbon monoxide via photoinitiated free radical-mediated carbonylation. A solution of an alkyl iodide in a homogenous binary organic solvent-water mixture is introduced into a high-pressure photochemical reactor containing [11C]carbon monoxide. Then the reactor contents are pressurized to 40 MPa and irradiated with ultraviolet light for 6 min. The labeled product is purified using HPLC. All manipulations with radioactivity including the labeling synthesis are carried out on an automated Synthia system. In a typical case, 3.19 GBq of purified [1-11C]1,10-decanedicarboxylic acid (with a specific radioactivity of 188 GBq/μmol) can be obtained within 35 min after the end of a 10-μAh bombardment. Compared to previous labeling methods, this protocol is compatible with a wider range of functional groups, utilizes less-sensitive precursors, and is less subject to isotopic dilution.

National Category
Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-83892 (URN)10.1038/nprot.2006.112 (DOI)000251002500039 ()17406310 (PubMedID)
Available from: 2006-11-10 Created: 2006-11-10 Last updated: 2011-01-17Bibliographically approved
Itsenko, O., Kihlberg, T. & Långström, B. (2005). Carboxylation of Alkyl Iodides with [11C] and (13C)Carbon Monoxide: Using Sulfoxides as Oxygen Nucleophiles. Synlett (20), 3154-3156
Open this publication in new window or tab >>Carboxylation of Alkyl Iodides with [11C] and (13C)Carbon Monoxide: Using Sulfoxides as Oxygen Nucleophiles
2005 (English)In: Synlett, no 20, p. 3154-3156Article in journal (Refereed) Published
Abstract [en]

11C-Labeled carboxylic acids were prepared from alkyl iodides and [11C]carbon monoxide by irradiation by UV light in anhydrous DMSO solutions in the presence of triethylamine. Sulfoxides other than DMSO can be used and may be used in stoichiometric amounts using inert solvents.

Keywords
sulfoxides, radical reactions, carbonylations, carboxylic acid, photochemistry
National Category
Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-83888 (URN)doi:10.1055/s-2005-922751 (DOI)
Available from: 2006-11-10 Created: 2006-11-10 Last updated: 2011-01-12
Itsenko, O. & Långström, B. (2005). Photoinitiaed Free Radical Carbonylation Enhanced by Photosensitizers. Organic Letters, 7(21), 4661-4664
Open this publication in new window or tab >>Photoinitiaed Free Radical Carbonylation Enhanced by Photosensitizers
2005 (English)In: Organic Letters, Vol. 7, no 21, p. 4661-4664Article in journal (Refereed) Published
Abstract [en]

The enchanicing effect of several photsensitizers in photoinitiated radical carbonylation is demonstrated and applied to acceleate the synthesis of compounds labeled with short-lived 11C. With the sensitizers, the synthesis of [carbonyl-11C]esters and acids from alkyl iodides, [11C]carbon monoxides, alcohols, and water provided up to 75-85% decay-corrected radiochemical yields in 6-min reactions under mild conditions. Acetone was used as a sensitier in preparing 13C-substituted 1,10-decanedicarboxylic acid from (13C)carbon monoxide.

Identifiers
urn:nbn:se:uu:diva-74530 (URN)
Available from: 2005-10-06 Created: 2005-10-06 Last updated: 2011-01-11
Itsenko, O. & Långström, B. (2005). Radical-Mediated Carboxylation of Alkyl iodides with [11C]Carbon Monoxide in Solvent Mixtures. J. Org. Chem (70), 2244-2249
Open this publication in new window or tab >>Radical-Mediated Carboxylation of Alkyl iodides with [11C]Carbon Monoxide in Solvent Mixtures
2005 (English)In: J. Org. Chem, no 70, p. 2244-2249Article in journal (Refereed) Published
Abstract [en]

[carboxyl-11C]Carboxylic acids were prepared from alkyl iodides via photoinitiated radical reactions using 10-8 mol of [11C]carbon monoxide in binary and ternary homogeneous solvent mixtures. Short-(isobutyric), medium-, and long-chain saturated fatty acids (heptadecanoic) were labeled with isolated decay-corrected radiochemical yields ranging from 55% to 70% in 5-7 min reactions. The conversion of [11C]carbon monoxide to products reached 80-90%. To obtain good yields in the reactions performed in water- acetonitrile and water-THF mixtures, the addition of tetrabut-ylammonium hydroxide or potassium hydroxide was essential. The carboxylation was efficient for primary and secondary alkyl iodides. The carboxylation of tertiary iodides was feasible for 1-iodoadamantane but not for tert-butyl iodide. The dependence of the radiochemical yields on reaction time, photoirradiation conditions, and organic and inorganic additives was studied. The method provides a one-step route to [carboxyl-11C]carboxylic acids; traditional methods, in contrast, would require several steps. For example, using the devised reaction, conditions, 3.19 GBq of purified [1-11C]1,10-decanedicarboxylic acid (specific radioactivity 188 GBq/umol) was obtained within 35 min of the end of 10 uAh bombardment. (1-13C)4-Phenylbutyric acid was synthesized using (13C)-carbon monoxide for identifying the labelling position with 1H and 13C NMR.

National Category
Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-69985 (URN)doi:10.1021/jo047806s CCC (DOI)
Available from: 2005-04-13 Created: 2005-04-13 Last updated: 2011-01-12
Itsenko, O., Kihlberg, T. & Långström, B. (2005). Synthesis of Aliphatic [carbony.-11C]Esters Using [11C]Carbon Monoxide. Eur. J. Org. Chem., 3830-3834
Open this publication in new window or tab >>Synthesis of Aliphatic [carbony.-11C]Esters Using [11C]Carbon Monoxide
2005 (English)In: Eur. J. Org. Chem., p. 3830-3834Article in journal (Refereed) Published
Abstract [en]

Aliphatic esters were labelled with a short-lived radionuclide,11C with t½=20.3 min, at the carbonyl position using [11C]carbon monoxide via rapid (6 min) photoinduced radical-mediated carbonylation reactions. The esters were prepared from primary, secondary, and tertiary alkyl iodides, and various alcohols, including tert-butyl alcohol and phenol. The use of strong bases was necessary to achieve good radiochemical yields in short reaction time. Isolated decay-corrected radiochemical yields were in the range of 40-68%. For example, methyl hydrogen dodecanoate was labelled at the ester carbonyl in 61% isolated decay-corrected radiochemical yield with a specific radioactivity of 158 GBq/umol within approcimately 25 min of the production of [11C]carbon monoxide. Two (13C]substituted esters were synthesised using this method to verify the labelling position.

Keywords
Carbon-11, Carbon-13, Isotopic labelling, Esters, Radicals, Carbonylation
National Category
Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-83887 (URN)doi:10.1002/ejoc.200500269 (DOI)
Available from: 2006-11-10 Created: 2006-11-10 Last updated: 2011-01-12
Itsenko, O., Kihlberg, T. & Långström, B. (2004). Photoinitiated Carbonylation with [11C]Carbon Monoxide Using Amines and Alkyl Iodides. J. Org. Chem. (69), 4356-4360
Open this publication in new window or tab >>Photoinitiated Carbonylation with [11C]Carbon Monoxide Using Amines and Alkyl Iodides
2004 (English)In: J. Org. Chem., no 69, p. 4356-4360Article in journal (Refereed) Published
National Category
Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-69956 (URN)
Available from: 2005-04-12 Created: 2005-04-12 Last updated: 2011-01-12
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