Peptide derivatives

摘要

Compounds represented by the following general formula and salts thereof; Y-L-Tyr-Q-NR1-CH(R2)-CO-X, wherein R1 represents hydrogen or C1-6 alkyl; R2 represents optionally substituted benzyl; Q represents D- or L-Arg; Y represents two hydrogen atoms of N-terminal amino group of L-Tyr, or one or two functional groups substituting for the hydrogen atoms, for example, a C1-6 alkyl optionally having amino or carboxy; and X represents N-methyl-beta-alanine and other. The compounds have analgesic effect and can be used for the treatment of cancer pain or the like.