| abstract |
(57) [Summary] [Structure] A cephalosporin derivative having a quaternary salt type substituent at the 3-position represented by the following formula. [Chemical 6] (In the formula, X is a carbon atom or a nitrogen atom, Y is a sulfur atom, an oxygen atom, or a nitrogen atom substituted with a lower alkyl group (which may be partially substituted with a substituent)). R 1 represents a hydrogen atom, a lower alkyl group or a substituted lower alkyl group, and R 2 represents a lower alkyl group, a substituted lower alkyl group, a lower alkylene group or a substituted lower alkylene group. Ring A represents a 6-membered unsaturated heterocycle containing at least one nitrogen atom.) [Effect] This compound has excellent antibacterial activity and is useful as a therapeutic agent for various bacterial infections. |