SYNTHESIS AND IN VITRO ACTIVITY OF NOVEL QUATERNARY AMMONIUM CARBAPENEMS: 2-PYRIDINIOPROPYL AND 1-PYRIDINIOETHYL CARBAPENEMS

Abstract

The synthesis of new carbapenems having either a pyridiniopropyl group at the 2-position or a pyridinioethyl group at the 1-position is described, along with the preparation of their corresponding hydroxy and acetoxy analogs. The antibacterial activity, susceptibility to dehydropeptidase-I (DHP-I) enzyme and chemical stability of these new carbapenems are also reported. 2-Pyridiniopropylcarbapenem 4 was found to possess excellent antibacterial activity. It was more stable chemically and less susceptible to the DHP-I enzyme than the thio analog 3. 1-Pyridinioethylcarbapenem 5 showed significantly reduced antibacterial activity as compared to 2-pyridiniopropylcarbapenem 4.