| 摘要 |
A compound of the formula: …<CHEM>… wherein X<1>, X<2> and X<3> are each amino or protected amino,… X<4> is hydrogen or hydroxy,… R<1> is hydrogen or lower alkyl, and… R<2> is higher alkanoyl which may have one or more suitable substituent(s), higher alkenoyl, or higher alkylcarbamoyl, or pharmaceutically acceptable salt thereof, processes for its preparation, pharmaceutical compositions containing them in association with a non-toxic, pharmaceutically acceptable carrier or excipient, and use thereof as an antimicrobial agent. |
