Journal of Antimicrobial Agents

New Quinoxalinyl Chalcone Derivatives: Search for Potent Antimicrobial Agents

Abstract

Geetha VM, Usha RU, Raghuveer P, Ramalingam P, Ravindra RJ, et al

Owing to the prevalence of antimicrobial resistance and its arising threat rendered by the ineffectiveness of existing antibiotics, the present work was aimed to generate new 5/6 substituted quinoxalinyl chalcones derivatives. A total of 16 compounds were synthesized and characterized by IR, 1H NMR, 13C NMR and mass spectral studies. The antimicrobial activity against resistant pathogens was by micro-dilution assay method. The result revealed that compounds bearing 2,4-dichloro benzylidine and 4-fluoro benzylidine moiety demonstrated promising antibacterial and antifungal activities against the selected pathogenic bacteria and fungi. It was observed that chalcones of 3,4- dihydroquinoxalin-2(1H)-one exhibited better activity (MIC: 2.57 ÃÃ?½¼M) as compared to the chalcones of quinoxalin-2,3(1H,4H)-dione. The ClogP values of the synthesized compounds were in good agreement with antifungal activity indicated the significance of lipid solubility better cell wall penetration. Overall quinoxalinyl chalcones exhibited broad spectrum antimicrobial activity.Owing to the prevalence of antimicrobial resistance and its arising threat rendered by the ineffectiveness of existing antibiotics, the present work was aimed to generate new 5/6 substituted quinoxalinyl chalcones derivatives. A total of 16 compounds were synthesized and characterized by IR, 1H NMR, 13C NMR and mass spectral studies. The antimicrobial activity against resistant pathogens was by micro-dilution assay method. The result revealed that compounds bearing 2,4-dichloro benzylidine and 4-fluoro benzylidine moiety demonstrated promising antibacterial and antifungal activities against the selected pathogenic bacteria and fungi. It was observed that chalcones of 3,4- dihydroquinoxalin-2(1H)-one exhibited better activity (MIC: 2.57 ÃÃ?½¼M) as compared to the chalcones of quinoxalin-2,3(1H,4H)-dione. The ClogP values of the synthesized compounds were in good agreement with antifungal activity indicated the significance of lipid solubility better cell wall penetration. Overall quinoxalinyl chalcones exhibited broad spectrum antimicrobial activity.