Synthesis and biological evaluation of 2-aminobenzamide derivatives as antimicrobial agents: opening/closing pharmacophore site.

A series of new 2-aminobenzamide derivatives (1-10) has been synthesized in good to excellent yields by adopting both conventional and/or a time-efficient microwave assisted methodologies starting from isatoic anhydride (ISA) and characterized on the basis of their physical, spectral and microanalytical data. Selected compounds of this series were then tested against various bacterial (Bacillus subtilis (RCMB 000107) and Staphylococcus aureus (RCMB 000106). Pseudomonas aeruginosa (RCMB 000102) and Escherichia coli (RCMB 000103) and fungal strains (Saccharomyces cerevisiae (RCMB 006002), Aspergillus fumigatus (RCMB 002003) and Candida albicans (RCMB 005002) to explore their potential as antimicrobial agents. Compound 5 was found to be the most active compound among those tested, which showed excellent antifungal activity against Aspergillus fumigatus (RCMB 002003) more potent than standard Clotrimazole, and moderate to good antibacterial and antifungal activity against most of the other strains of bacteria and fungi. Furthermore, potential pharmacophore sites were identified and their activity was related with the structures in the solution.

Synthesis, anti-microbial and molecular docking studies of quinazolin-4(3H)-one derivatives.

In this work, synthesis, antimicrobial activities and molecular docking studies of some new series of substituted quinazolinone 2a-h and 3a-d were described. Starting form 2-aminobenzamide derivatives 1, a new series of quinazolinone derivatives has been synthesized, in high yields, assisted by microwave and classical methods. Some of these substituted quinazolinones were tested for their antimicrobial activity against Gram-negative bacteria (Pseudomonas aeruginosa and Esherichia coli) and Gram-positive bacteria (Staphylococcus aureus, and Bacillus subtilis), and anti-fungal activity against (Aspergillus fumigatus, Saccharomyces cervevisiae, and Candida albicans) using agar well diffusion method. Among the prepared products, 3-benzyl-2-(4-chlorophenyl)quinazolin-4(3H)-one (3a) was found to exhibits the most potent in vitro anti-microbial activity with MICs of 25.6±0.5, 24.3±0.4, 30.1±0.6, and 25.1±0.5 µg/mL against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Esherichia coli, respectively. Compound 3a was found to exhibits the most potent in vitro anti-fungal activity with MICs of 18.3±0.6, 23.1±0.4, and 26.1±0.5 µg/mL against Aspergillus fumigatus, Saccharomyces cervevisiae, and Candidaal bicans, respectively.