Publikace detail

Towards stereoselective radiosynthesis of α-[11C]methylsubtituted aromatic α-amino acids ? a challenge of creation of quaternary asymmetric centre in a very short time.

Rok: 2007

Druh publikace: článek v odborném periodiku

Název zdroje: Journal of Labelled Compounds and Radiopharmaceuticals

Název nakladatele: John Wiley & Sons Ltd.

Místo vydání: Chichester

Strana od-do: 370-374

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
cze	Towards stereoselective radiosynthesis of α-[11C]methylsubtituted aromatic α-amino acids ? a challenge of creation of quaternary asymmetric centre in a very short time.	In positron emission tomography (PET) a-methyl amino acids have two potential applications: As analogues of neutransmitter precursors for the study of neurodegenerative diseases, and as non-metabolised analogues of proteinogenic amino acids for the study of amino acid uptake into normal and cancer cells. Clinical applications of such amino acids are strongly limited due to their poor availability. We carried out [11C]methylation of metalocomplex synthons derived from protected DOPA or tyrosine. For [11C]methylation, sodium hydroxide (5mg of fine dry powder) was sealed in a vial, which was flushed with dry nitrogen before addition of a solution of the complex (10 mg) and 11CH3I in 1,3-dimethylimidazolidin-2-one (300 ml). After 10 min at 258C, a 9% radiochemical yield (decay-corrected) of a mixture of the diastereomeric a-[11C]methylDOPA complexes or a 7% radiochemical yield of a mixture of the diastereomeric a-[11C]methyltyrosine complexes was achieved. Individual diastereomers were successfully separated by preparative HPLC, diluted with excess of water and extracted on C18 cartridges. Optimisation of the procedure including hydrolysis of the complexes (hydrolytic deprotection of enantiomerically pure amino acids) and subsequent purification of the enantiomers of a-[11C]methylDOPA and a-[11C]methyltyrosine is underway.
eng	Towards stereoselective radiosynthesis of α-[11C]methylsubtituted aromatic α-amino acids ? a challenge of creation of quaternary asymmetric centre in a very short time.	In positron emission tomography (PET) a-methyl amino acids have two potential applications: As analogues of neutransmitter precursors for the study of neurodegenerative diseases, and as non-metabolised analogues of proteinogenic amino acids for the study of amino acid uptake into normal and cancer cells. Clinical applications of such amino acids are strongly limited due to their poor availability. We carried out [11C]methylation of metalocomplex synthons derived from protected DOPA or tyrosine. For [11C]methylation, sodium hydroxide (5mg of fine dry powder) was sealed in a vial, which was flushed with dry nitrogen before addition of a solution of the complex (10 mg) and 11CH3I in 1,3-dimethylimidazolidin-2-one (300 ml). After 10 min at 258C, a 9% radiochemical yield (decay-corrected) of a mixture of the diastereomeric a-[11C]methylDOPA complexes or a 7% radiochemical yield of a mixture of the diastereomeric a-[11C]methyltyrosine complexes was achieved. Individual diastereomers were successfully separated by preparative HPLC, diluted with excess of water and extracted on C18 cartridges. Optimisation of the procedure including hydrolysis of the complexes (hydrolytic deprotection of enantiomerically pure amino acids) and subsequent purification of the enantiomers of a-[11C]methylDOPA and a-[11C]methyltyrosine is underway.	asymetris synthesis; a-methyl amino acids; carbon-11; [11C]methylation; DOPA; tyrosine; nickel; complexes

Search

Přihlášení pro studenty

Přihlášení pro zaměstnance

Publikace detail

Katedry

Ústavy a pracoviště

Jak nás najdete?

Služby

Často hledáte