title: Potential prodrugs of 6-acetylmethylenepenicillanic acid (Ro 15-1903).
abstract: The synthesis and biological activities of a series of non-classical penicillins are described. These compounds were synthesized by treating the pivaloyloxymethyl ester of 6-acetylmethylenepenicillanic acid (Ro 15-1903) with various nucleophiles. They were found to be less active against the beta-lactamases from Proteus vulgaris 1028, Escherichia coli 1024, Klebsiella pneumoniae NCTC 418 and E. coli RTEM than the parent compound. Nevertheless, synergy with ampicillin against whole bacterial cells producing beta-lactamases was evident, although the single compounds did not exhibit antibacterial properties. With the compounds 2a and 2b, synergistic interaction with ampicillin could also be demonstrated in mice.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D004357:Drug Synergism; D010397:Penicillanic Acid / Q000138:chemical synthesis* / Q000031:analogs & derivatives; D065093:beta-Lactamase Inhibitors
chemical_list: D065093:beta-Lactamase Inhibitors; D000667:Ampicillin; C036977:6-acetylmethylenepenicillanic acid; D010397:Penicillanic Acid