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Abstract

Despite significant progress made in the treatment of infectious diseases, caused by bacteria and fungi, it remains a major worldwide health problem due to rapid development of resistance against the existing antimicrobial drugs. In the present investigation, a novel series of chalcones 2a-2h were synthesized by the clasein-schmidt condensation of various aldehydes with methyl ketone in the presence of KOH in ethanol which lead to the formation of new chalcones. The structures of these compounds were elucidated by, IR, 1H-NMR spectral data. The in vitro antibacterial activity of these compounds was evaluated against two Gram positive and two Gram-negative bacteria Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Pseudomonas aeruginosa by microdilution method and then the minimum inhibitory concentration (MIC) of these compounds was determined. The results showed that compounds 2d, 2e and 2h showed most promising antibacterial activity as compared to the antibiotics ciprofloxacin in (Tables 1). Compound 2e which carries the nitro substituent appears to exhibit the highest antibacterial activity against all gram positive and gram negative bacteria.