Synthesis of 2-Phenylchromen-4-one derivatives by conventional and microwave: Assisted techniques, and their antimicrobial evaluation

Abstract

Two derivatives of 2-phenylchromen-4-one (flavone ring) with their precursors 1-(2-hydroxyphenyl)-3-(phenyl)-prop-2-en-1-one (chalcone ring) have been synthesized by conventional and microwave-assisted heating techniques. A comparative study was carried out between the two methods. The structures of the synthesized compounds were determined by IR, 1H-NMR and 13C-NMR spectral data. The antibacterial and antifungal screens were performed against six human pathogenic bacteria viz. Bacillus cereus (G+), Staphylococcus aureus (G+), Escherichia coli (G-), Vibrio choloriae (G-), Pseudomonas aeruginosa (G-), and Salmonella typhi (G-) by the filter paper disc diffusion method and four plant as well as mold fungi. viz. Aspergillus flavus, Aspergillus ochraceus, Aspergillus niger and Rhizopus spp. by the poisoned food technique, respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these synthesized compounds in comparison to ampicillin were also determined by broth micro-dilution method. Compounds 2-(2,4-dimethoxyphenyl)-chromen-4-one (6) and 2-(4-ethoxyphenyl)-chromen-4-one (7) were found to possess significant antibacterial and antifungal activities.