7-Carboxymethoxyphenylacetamido-3-cephem derivatives represented by the formula ##STR1## wherein R.sub.1 means hydroxy, C.sub.1 -C.sub.4 alkanoyloxy or C.sub.1 -C.sub.4 alkoxycarbonyloxy, R.sub.2 is hydrogen or methoxy, R.sub.3 denotes C.sub.1 -C.sub.4 alkanoyloxy, substituted or unsubstituted nitrogen-containing heterocyclic-thio or substituted or unsubstituted pyridinium with a proviso that, when R.sub.3 denotes the substituted or unsubstituted pyridinium, R.sub.3 forms an intramolecular salt with the carboxy at the 4-position of the cephem nucleus, and A is a group of the following formula: ##STR2## in which R.sub.4 and R.sub.5 are individually hydrogen or C.sub.1 -C.sub.4 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.
7-羧
甲氧基苯乙
酰胺基-3-
头孢菌素衍
生物的
化学式为##
STR1##其中R.sub.1代表羟基,C.sub.1 -C.sub.4烷酰
氧基或C.sub.1 -C.sub.4烷
氧羰基
氧基,R.sub.2为
氢或甲
氧基,R.sub.3表示C.sub.1 -C.sub.4烷酰
氧基,取代或未取代的含
氮杂环硫或取代或未取代的
吡啶阳离子,但当R.sub.3表示取代或未取代的
吡啶阳离子时,R.sub.3与
头孢菌素核的4位羧基形成分子
内盐,A为以下
化学式的基团:##
STR2##其中R.sub.4和R.sub.5分别为
氢或C.sub.1 -C.sub.4烷基,及其药用可接受的盐,对革兰氏阴性细菌,特别是
铜绿假单胞菌、克雷伯菌、马克赛菌等表现出优异的抗菌活性。