Abstract: Cephalosporin compounds of formula (I): ##STR1## wherein: R.sup.1 is a hydrogen or an amino protecting group;R.sup.2 and R.sup.3 are, independently, a hydrogen or a hydroxy protecting group, or form together a cyclic diol protecting group;R.sup.4 and R.sup.5 are, independently, a hydrogen or a carboxyl protecting group;X and Y are a nitrogen and a carbon atom, respectively, or a carbon and a nitrogen atom, respectively;R.sup.6 and R.sup.7 are, independently, a hydrogen or an amino, substituted amino, hydroxy, alkoxy, C.sub.1-4 alkyl, carboxyl or alkoxy carbonyl group, or jointly form a C.sub.3-7 cycloalkyl group together with the carbon to which they are attached, when X and Y are a nitrogen and a carbon, respectively, or R.sup.7 is a hydrogen or an amino group when X and Y are a carbon and a nitrogen, respectively; andQ is .dbd.CH-- or .dbd.

Abstract: The present invention relates to a cephalosporin compound represented by the following general formula (I): ##STR1## its pharmaceutically acceptable non-toxic salt, physiologically hydrolyzable ester, hydrate or solvate, or isomers thereof, in whichR.sup.1 represents hydrogen or an amino-protecting group,R.sup.2 and R.sup.3 can be identical or different and independently of one another represent hydrogen or a hydroxy-protecting group, orR.sup.2 and R.sup.3 together can form a cyclic diol-protecting group,R.sup.4 represents hydrogen or a carboxyl-protecting group,R.sup.5, R.sup.6 and R.sup.7 independently of one another represent hydrogen, amino or substituted amino, hydroxy, alkoxy, C.sub.1-4 alkyl, carboxyl or alkoxycarbonyl, orR.sup.5 and R.sup.6 together with the carbon atoms to which they are attached can form a C.sub.3-7 cycle, andQ represents CH or N,and to a process for preparation thereof and a pharmaceutical composition containing the compound (I) as an active ingredient.