A method for the preparation of lysine - tryptophan - oligopeptides and their physiologically acceptable derivatives and salts

摘要

A process for the preparation of ologopeptides constituted by lysinyl and tryptophanyl residues characterised by the following general formula (1): (Lys)a(Trp)b 1 wherein Lys represents a lysinyl residue, Trp represents a tryptophanyl residue, ao and bo with the sole condition that when the peptide link, -CONH-, has originated through the amino group of the lysine, that the amino group be that in the alpha position to the carboxyl which gives rise to the formation of said link is carried out in three stages. Firstly, a compound of general formula 2 is reacted with a compound of general formula 3, IMAGE in which R1 and R2 independently represent beta -methylenidole or epsilon - aminobutyl with the -NH2 group protected or any residue of any peptide sequence (Lys)c-(Trp)d (wherein c and/or do) with the condition that at least one of R1 and R2 is a residue of beta -methylenidole or protected epsilon -aminobutyl, and R3 is an alkyl aryl or arylalkyl group, whereby to obtain the compound of the general formula 4 shown below: IMAGE Secondly, the o-nitrosulphenyl group is eliminated and replaced by a hydrogen atom. Thirdly, the resultant amino-ester is treated to remove any amine-protecting groups and is then optionally saponified, followed by neutralization, to give the free peptide 1. Physiologically useful derivatives or salts may then be formed therefrom.