| abstract |
Novel cephem compounds excellent in antimicrobial activity, stability and peroral absorbability, which are compounds represented by general formula (I) or esters thereof or salts of the esters; a process for the preparation of them; and drugs containing them. In said formula, R1 is phosphono or a group convertible into phosphono; R2 is hydrogen or a group bonded to the oxygen atom through a carbon atom; Q and X are each nitrogen or CH; Y is S, O or CH¿2?; n is 0 or 1; and either of R?3 and R4¿ is an optionally substituted pyridinium group and the other is hydrogen or an optionally substituted hydrocarbon group, or alternatively R?3 and R4¿ may be united to form an optionally substituted heterocyclic group having a quaternary nitrogen atom. |