Phenylalanine-glycine derivatives, process for preparation thereof, and pharmaceutical composition containing said derivatives

摘要

A phenylalanine-glycine derivative of the general formula (I): <IMAGE> (I) wherein R represents a residue of an antitumor substance, or a salt or ester thereof, a process for preparation thereof, and a pharmaceutical composition containing the same are described. The novel conjugate of the phenylalanine-glycine derivative and the antitumor substance exhibits superior antitumor activity in comparison with the case wherein an antitumor substance is administered singly or as a mixture with phenylalanine.