A series of bischalcones (4a-j) were synthesized and evaluated for their antimicrobial actions. Bischalcones were prepared by condensing 1,1´-(4,6-dimethyl-1,3-phenylene)diethanone (3) with appropriate aromatic aldehydes in ethanol in presence of KOH. The structures of the synthesized compounds were confirmed on the basis of 1H NMR, Mass and elemental analysis results. The antimicrobial screening of the title compounds was performed at a concentration of 100 μg/mL by cup plate method; the compounds inhibiting growth of one or more of the microorganisms were further tested
for their minimum inhibitory concentration (MIC) by turbidity method. The results revealed that the compound 4f showed good activity against S. aureus, E. coli and P. aeruginosa with MIC-12.5 μg/mL. Similar type of activity was shown by the compound 4g against S. aureus and E. coli and, by the compound 4j against S. aureus and P. aeruginosa with MIC-12.5 μg/mL.