SYNTHESIS OF ENANTIOMERICALLY PURE ALPHA-[C-14]METHYL-L-TRYPTOPHAN

Citation
S. Mzengeza et al., SYNTHESIS OF ENANTIOMERICALLY PURE ALPHA-[C-14]METHYL-L-TRYPTOPHAN, Applied radiation and isotopes, 44(9), 1993, pp. 1167-1172
Citations number
15
Categorie Soggetti
Nuclear Sciences & Tecnology","Radiology,Nuclear Medicine & Medical Imaging
Journal title
Applied radiation and isotopes
ISSN journal
09698043 → ACNP
Volume
44
Issue
9
Year of publication
1993
Pages
1167 - 1172
Database
ISI
SICI code
0969-8043(1993)44:9<1167:SOEPA>2.0.ZU;2-R
Abstract
A practical method for the preparation of large amounts of enantiomeri cally pure alpha-[C-14]methyl-L-tryptophan using the enzymatic resolut ion of the corresponding D,L-Methyl ester is reported. The radiolabell ed alpha-methyl group was introduced using the alpha-methylation of th e lithium enolate of the Schiff base Of L-tryptophan methyl ester. Hyd rolysis of the Schiff base with 1 N HCl provided the D,L-methyl ester of alpha-[C-14]methyl tryptophan. Enantioselective enzymatic hydrolysi s of the L-methyl ester by alpha-chymotrypsin gave the enantiomericall y pure alpha-[C-14]methyl-L-tryptophan. The overall yield of this prep aration was 33%.