title: Cefonicid: a stable beta-lactamase inhibitor.
abstract: The stability of cefonicid (SK&F 75073) towards representatives of six major classes of beta-lactamases was determined using a spectrophotometric assay. Cefonicid was stable to hydrolysis by the Type I enzyme from Enterobacter cloacae and by the enzyme from the anaerobe, Bacteroides fragilis. It was 6 to 7 times more stable than cefamandole to the Type IIIA and B enzymes from Escherichia coli, a little less stable than this antibiotic to the Type V enzyme from E. coli, and of equal stability to the Type IV enzyme from Klebsiella aerogenes. Cefonicid was a non-competitive inhibitor (Ki of 0.8 x 10(-6)M) of cephalothin hydrolysis by the Type I enzyme.
mesh_terms: D002435:Cefamandole / Q000031:analogs & derivatives / Q000494:pharmacology*; D015790:Cefonicid; D002511:Cephalosporins / Q000494:pharmacology; D002512:Cephalothin / Q000494:pharmacology; D004355:Drug Stability; D006088:Gram-Negative Aerobic Bacteria / Q000201:enzymology; D006089:Gram-Negative Anaerobic Bacteria / Q000201:enzymology; D006868:Hydrolysis; D065093:beta-Lactamase Inhibitors
chemical_list: D002511:Cephalosporins; D065093:beta-Lactamase Inhibitors; D002435:Cefamandole; D015790:Cefonicid; D002512:Cephalothin