PEPTIDE, PROCESS FOR PREPARATION THEREOF AND USE THEREOF

摘要

A compound of the formula or its pharmaceutically acceptable salt: …… wherein… R<1> is substituted or unsubstituted lower alkanoyl, or substituted or unsubstituted aralkanoyl,… R<2> and R<3> are each carboxy or protected carboxy,… R<4> is hydrogen or an amino protective group, and… R<5> is hydrogen or lower alkyl,… and processes for their preparation and also a pharmaceutically composition comprising, as an effective ingredient, the above compound in association with pharmaceutically acceptable carriers.