Cephalosporin derivative and pharmaceutical composition

摘要

A cephalosporin derivative of the formula <IMAGE> wherein R is a hydrogen atom, a lower alkyl group which may have been substituted or a carbamoyl group which may have been substituted; R1 is hydrogen atom or a methoxy group; R2 is a hydrogen atom, an acyloxy group, or a nitrogen-containing 5-membered heterocyclic thio group which may have been substituted; R3 is a free amino group or an amino group having a protective group; and R4 is a free carboxy group or a carboxy group having a protective group or the salts thereof. The compound of this invention has an excellent antibacterial activity against gram negative bacteria and gram positive bacteria.