| abstract |
A compound of the formula: ##STR1## wherein R 1 represents mandeloyl or 2-(3-sydnone)-acetyl group and R 2 represents a hydrogen atom, a halogen, an alkyl or an alkoxyl group, or a pharmaceutically accetable salt thereof, is found to have a broad antimicrobial spectrum and, in particular, effective against gram-negative bacteria as well as gram-positive ones. Examples thereof include 7-[D-(-)-mandelamido]-3-[6'-(3'-methylpyridazinyl)-thio-methyl]-3-cephem-4-carboxylic acid 2'-oxide, 7-[D-(-)-mandelamido]-3-[6'-(3'-methoxypyridazinyl)-thiomethyl]-3-cephem-4-carboxylic acid 1'-oxide, and 7-[2'-(3'-sydnone)acetamido]-3-[6"-(3"-methylpyridazinyl)-thiomethyl]-3-cephem-4-carboxylic acid 2"-oxide. |