Synthesis and biological evaluation of novel heterocyclic analogues

Abstract

This project was aimed at the synthesis of some novel heterocyclic analogues like Schiff bases and cyclization of Schiff bases to synthesize Beta-lactam derivatives. The Schiff bases have been synthesized by refluxing equimolar (0.1 mole) quantities of a primary amine and aldehyde or ketone. The Beta-lactam derivatives have been synthesized by refluxing equimolar (0.1 mole) quantities of Schiff base and chloroacetylchloride in presence of triethylamine. The synthesized Schiff bases and Beta-lactam derivatives were characterized by IR, NMR, Mass spectra followed by elemental analysis for carbon, hydrogen and nitrogen. All the compounds were screened for their in vitro antibacterial activity against two Gram +ve (Staphylococcus aureus, Bacillus subtilis) and two Gram -ve (Escherichia coli, Pseudomonas aeruginosa) bacterial strains by agar-well diffusion method. Those compounds which showed maximum significant activity were selected for minimum inhibitory concentration (MIC) studies. newlineThe Schiff bases were found to exhibit either no or low to moderate activity against one or more bacterial species. On contrary all the Beta-lactam derivatives exhibited varied activity against different bacteria. The inactive and less active Schiff bases became active more active after cyclization, respectively. These studies may serve as a basis for the chemical modifications directed towards the development of a new class of antibacterial agents.