Abstract

In the present communication synthesis of pyrazole-containing dihydropyrimidinone motifs (4a-o) and their antimicrobial activity and cytotoxicity were reported. The newly synthesized compounds were characterized using infrared, proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance and mass spectral techniques. Compounds 4b, 4c, 4f, 4g, 4i and 4j were the most active derivatives identified during antimicrobial activity screening. On the basis of antibacterial activities, it was observed that compounds 4b and 4c exhibited activity against methicillin resistant Staphylococcus aureus with minimum inhibitory concentrations of 12.5 and 6.25 µg/ml, respectively. From structure activity relationship studies, it could be concluded that electron withdrawing groups played a crucial role in enhancing antimicrobial and cytotoxic effects of title compounds. In addition, the results of the cytotoxicity studies indicated that compounds 4b, 4c, 4g and 4j possessed lower levels of cytotoxicity.