Abstract
This work describes the synthesis, characterization and antimicrobial evaluation of a series of new 1,3,4-oxadiazole linked benzopyrimidinones. Their structures were confirmed on the basis of H-1, C-13 NMR and ES-HRMS analysis. Their molecular geometry are also studied theoretically by the Density Functional Theory (DFT) method with B3LYP/6-31++G (d,p). All the calculations were done in DMSO, using conductor like polarizable continuum (CPCM). The target compounds were screened for their antimicrobial activity against four types of pathogenic bacteria and three fungal strains. Biological results revealed that some of these compounds demonstrated excellent to moderate antimicrobial activities with minimum inhibitory concentration (MIC) values ranging from 10.8 to 140.7 mu M. Notably, compounds 5g and 5h showed the highest inhibitory activity against all bacterial strains with MIC values ranging from 111.3 to 10.8 mu M against S. aureus, E. coll. and P. aeruginosa, and displayed a good antifungal activity against C. albicans with MIC values of 10.8 and 27,8 mu M, respectively. The structure-activity relationship (SAR) was discussed. (C) 2020 Elsevier B.V. All rights reserved.