Synthesis and biological evaluations of enoxacin carboxamide derivatives.

The present work deals with the synthesis of various enoxacin analogues via nucleophilic substitution of 3-carboxylic acid moiety of the drug by aromatic amines. The free carboxylic group was utilized in the formation of amides and the effect of functional group exchange on different biological activities of the parent was evaluated. The structure of these derivatives was established by various spectroscopic techniques and mass spectrometry. The derivatives were evaluated as antibacterial agents against a series of Gram-positive and Gram-negative bacteria whereby some of them displayed considerably improved antimicrobial profile against Gram-negative test strains. Additionally unlike enoxacin, the derivatives were also found to modulate oxidative burst response of phagocytes exhibiting moderate to significant inhibitory activity.