| 摘要 |
A compound of the formula: <IMAGE> wherein R1 represents hydrogen or an alkyl group, X represents oxygen or sulfur or a group of formula -NR2 (where R2 is hydrogen or an alkyl group and in the case of alkyl, it may form a ring jointed with R1), and Y represents acetoxy group or a group of formula -SR3 (where R3 is a nitrogen-containing heterocyclic group), or a pharmaceutically acceptable salt thereof, is found to have a broad antimicrobial spectrum and, in particular, effective against gram-negative bacteria including Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Proteus morganii, as well as gram positive ones. Thus, these compounds may be used for antimicrobial agents in therapeutical purposes. |
