Synthesis of C6-Ethylidene Meropenem Derivative with Antimicrobial Activity

The development of novel β-lactamase inhibitors with activity against various clinically relevant β-lactamase producing strains is one of the most important strategies to sustain the clinical efficacy of β-lactam antibiotics. With intention to eliminate antibiotic activity of meropenem with preserved activity against β-lactamases C6-hydroxyethyl side chain of meropenem was transformed to C6-ethylidene moiety. IC50 values of C6-ethylidene derivative of meropenem were in low mM range against TEM-1, SHV-1 and AmpC enzymes and were clearly inferior to meropenem. Surprisingly, some of the antimicrobial activity of meropenem was preserved implying that C6-hydroxyethyl side chain is not essential to retain antibiotic activity of meropenem.