Cyclic antimicrobial peptides and preparation thereof.

摘要

A polypeptide compound of the following general formula : <CHEM> wherein R<1> is hydrogen, R<2> is acyl group, R<3> is hydroxy or acyloxy, R<4> is hydroxy or hydroxysulfonyloxy, R<5> is hydrogen or lower alkyl which may have one or more suitable substituent (s), and R<6> is hydrogen, hydroxy or acyl (lower) alkylthio and a pharmaceutically acceptable salt thereof, processes for their preparation and pharmaceutical compositions comprising them as an active ingredient.