Synthesis and antimicrobial evaluation of new quinazolinone derivatives containing thiourea and thiazolidine moieties

With the aim of finding novel compounds with good antimicrobial activity to counteract drug resistance, a new series of quinazolinones featuring thiourea and thiazole groups was synthesized through the reaction of 4-amino-N-(4-oxo-2-phenyl-1, 2-dihydroquinazolin-3(4H)-yl)benzamide with methyl isothiocyanate and subsequent treatment with dialkyl acetylene dicarboxylate. All synthesized compounds were characterized by spectroscopic data and elemental analysis. The antimicrobial activity of synthesized compounds was evaluated against two bacteria strains (Escherichia coli PTCC1330; Staphylococcus aureus PTCC 1431) and two fungi strains (Aspergillus niger PTCC5010; Candida albicans ATCC 10231). Almost all products exhibited good antibacterial and antifungal activities which indicated that insertion of thiourea and thiazolidine moieties considerably increased the antimicrobial properties of quinazolinones. Therefore, these compounds can be good candidates for clinical treatments, avoiding possible drug resistance problems in humans.