Synthesis and biological activity of novel 1β-Methylcarbapenems with oxyiminopyrrolidinylamide moiety

The synthesis and antibacterial activity of novel 1β-methylcarbapenems 1a–f bearing oxyiminopyrrolidinylamide moiety at C-5 position of pyrrolidine are described. Most compounds exhibited comparable antibacterial activity to meropenem against a wide range of Gram-positive and Gram-negative organisms including Pseudomonas aeruginosa isolates. Of these carbapenems, 1a showed potent and broad spectrum of antibacterial activity and similar stability to DHP-I to meropenem. Against clinical isolates of 40 Gram-negative bacterial species including MDR and ESBL-producing strains, the selected carbapenem 1a possessed excellent in vitro activity except for MDR P. aeruginosa, and was comparable in potency to meropenem.