Semisynthetic β-Lactam Antibiotics. IV. Synthesis and Antibacterial Activity of New Ureidocephalosporin and Ureidocephamycin Derivatives Containing a Catechol Moiety or Its Acetate

New ureidocephalosporin and ureidocephamycin derivatives containing a catechol moiety or its acetate were prepared and their minimum inhibitory concentration values against various microorganisms were determined. Among these compounds, the ureidocephalosporins (2, 3Aa, 3Ba) and ureidocephamycins (4, 5) carrying a methyl group on the nitrogen atom of the ureido bond showed strong activities against Pseudomonas aeruginosa. 7β- [(R) -2-[3- (3, 4-Dihydroxybenzoyl) -3-methylureido] -2-phenylacetamido] -7α-methoxy-3- [(1-methyl-1H-tetrazol-5-yl) -thiomethyl] -3-cephem-4-carboxylic acid (5) had the most potent activity in vitro against gramnegative bacteria, its activity being 8-to 32-fold and 4-fold greater than those of cefoperazone and ceftazidime, respectively, against two strains of P. aeruginosa. The structure-activity relationship is discussed.