SYNTHESIS AND ANTIMICROBIAL ACTIVITY OF CEPHALOSPORINS WITH A 1-PYRIDINIUM SUBSTITUENT CARRYING A 5-MEMBERED HETEROCYCLE AT THE C-3 POSITION

Abstract

A series of potent antimicrobial agents have been prepared. These derivatives are cephalosporins carrying a pyridine ring substituted with a heterocycle in the C-3 position. Some of them showed excellent activity not only against Gram-negative organisms including Pseudomonas aeruginosa but also against Gram-positive ones. In view of their biological and physico-chemical properties, 7β-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-[4-(2 or 5-oxazolyl)-1-pyridinium]methyl-3-cephem-4-carboxylate 8f (DQ-2522) and 8g (DQ-2556) were chosen as candidates for further evaluation.