New peptide, process for preparation thereof and pharmaceutical composition containing it.

摘要

A compound of the formula or its pharmaceutically acceptable salt: …… wherein R<1> and R<5> are hydrogen or certain substituents, R<2> is carboxy or protected carboxy, R<3> and R<4> are carboxy, protected carboxy or certain substituents with proviso that at least one of R<3> or R<4> is always carbamoyl, and processes for their preparation and also a pharmaceutical composition comprising as an ingredient the above compound.