ASYMMETRIC DEUTERATION OF N-ACETYL-(Z)-ALPHA,BETA-DEHYDROTRYPTOPHAN-(L)-PHENYLALANINE METHYL ESTER PRODUCED BY (L)-TRYPTOPHAN 2',3'-OXIDASE FROM CHROMOBACTERIUM VIOLACEUM - A NEW ROUTE FOR STEREOSPECIFIC LABELLING OF PEPTIDES

摘要

A novel approach to the synthesis of labelled (H-2, H-3) peptides through the catalytic asymmetric reduction of Delta(2)Trp containing peptides, using rhodium complexes with chiral diphosphine ligands as the catalysts, is described. Ac-Delta(2)Trp-(L)-Phe-OMe is used as a model substrate to study this new route. The (Z)-alpha,beta-dehydropeptide is produced by (L)-tryptophan 2',3'-oxidase from Chromobacterium violaceum in a single step reaction. Diastereomeric excesses up to 98 % have been obtained with (R,R)-dipamp as ligand in the catalyst. Extremely high stereoselectivities for producing the (L,L)- or (D,L)-isomer could be achieved using the appropriate chiral ligands. This method has good potential for stereospecific labelling (deuteration or tritiation) of peptides. (C) 1997 Elsevier Science Ltd. [References: 27]