| 摘要 |
7-Carboxymethoxyphenylacetamido-3-cephem derivatives represented by the formula <IMAGE> wherein R1 means hydroxy, C1-C4 alkanoyloxy or C1-C4 alkoxycarbonyloxy, R2 is hydrogen or methoxy, R3 denotes C1-C4 alkanoyloxy, substituted or unsubstituted nitrogen-containing heterocyclic-thio or substituted or unsubstituted pyridinium with a proviso that, when R3 denotes the substituted or unsubstituted pyridinium, R3 forms an intramolecular salt with the carboxy at the 4-position of the cephem nucleus, and A is a group of the following formula: <IMAGE> in which R4 and R5 are individually hydrogen or C1-C4 alkyl, and their pharmaceutically acceptable salts, exhibit excellent anti-bacterial activities against Gram-negative bacteria, particularly, Pseud. aeruginosa, Kleb. pneumoniae, Ser. marcescens and the like. |
