Synthesis and evaluation of 2 beta-oxyimino and alkenylpenicillanic acid sulfone derivatives as beta-lactamase inhibitors

The synthesis and in vitro synergies of 2 beta-alkenyl and oxyiminopenam su lfone derivatives are described. Most of the compounds synthesized exhibite d good inhibitory activities and synergistic antibacterial activities with piperacillin and ceftriaxone, respectively, against several beta-lactamase producing strains. Particularly the 2 beta-alkenylpenam sulfone derivatives , le and Ig, showed good synergistic activity with ceftriaxone against Citr obacter freundi NIH 10018-68 and Proteus vulgaris 20. Also the compounds 2a , 2c, and 2f, 2 beta-oxyiminopenam sulfone derivatives, exhibited improved synergistic activity with piperacillin against Citrobacter freundi NIH 1001 8-68.