FACILE SYNTHESIS OF(S)-5,5-DIFLUORONORLEUCINE AND ITS INCORPORATION IN BIOLOGICALLY ACTIVE PEPTIDES AS AN METHIONINE MIMETIC

摘要

Both Boc and Fmoc protected 5,5-difluoronorleucines(F_2Nle)were easily prepared from commercially available amino acid derivatives.F_2Nle can be viewed as a mimic of methionine in which the sulfur atom is replaced by the CF_2 moiety.Two analogues of methionine-containing biologically active peptides(fMLP and Met-enkephalin)were prepared.The validity of CF_2-substituted methionine analogues was confirmed in their biological assay.