Design, Synthesis and In-Vitro Antimicrobial and Cytotoxic Activity Screening of 5-Carboxamide Substituted 3, 4-Dihydropyrimidine-2 (1H) Ones

This paper describes the synthesis and in vitro biological evaluation of new compounds designated as 5(a-h) and 8(a-f). These compounds were synthesized by the reaction of thiazole derivative (3) or thiadiazole derivative (7) with urea and various aromatic aldehydes 4(a-h) in ethanol. The structures of the synthesized compounds were checked by IR,1H,13C NMR, and Mass spectroscopy. The antibacterial and antifungal activities of the compounds were evaluated against Escherichia coli (Gram-negative), Staphylococcus aureus (Gram-positive), and Candida albicans (fungus) using agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal/fungicidal concentration methods. The cytotoxic activities of these compounds against HT-29 and A-549 cancer cell lines were assessed in vitro by the MTT method. Our studies showed compounds 8c and 8f to have the most expressed antibacterial activity against S. aureus, while compounds 8c and 8d were the most potent against E. coli. Compounds 5h and 8e showed the highest antifungal activity against C. albicans, and compound 5f showed the most potent activity against the tested cancer cell lines. [Graphical Abstract]