Cephalosporin derivatives

Abstract

A compound of the formula: ##STR1## wherein R.sup.1 represents hydrogen or an alkyl group, X represents oxygen or sulfur or a group of formula --NR.sup.2 (where R.sup.2 is hydrogen or an alkyl group and in the case of alkyl, it may form a ring jointed with R.sup.1), and Y represents acetoxy group or a group of formula --SR.sup.3 (where R.sup.3 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.

Dependencies are inferred from the claim text.