Discovery of 1,2,3-triazoles incorporated benzoxazinones as potent antimicrobial agents: Synthesis, in vitro biological evaluation, DFT interactions and molecular docking

The study of the chemical and biological properties of molecules simultaneously comprising various heterocycles, such as fused 1,2,3-triazoles and benzoxazinones have been conducted as part of our ongoing research in the field of medicinal and organic chemistry. Two classes of 1,2,3-triazoles linked benzoxazinone derivatives were prepared from 2-((prop-2-yn-1-ylamino) methyl)-4H-benzo[d][1,3]oxazin-4-one 4 and substituted azides successfully CuAAC reaction and more efficient approach. The structures of these new triazole derivatives have been confirmed by Mass, 1H NMR, 13C NMR, and IR spectral data. From antibacterial studies, benzoxazinone-linked 1,2,3-triazoles 5a, 5d, and 6e were found to be most effective against P. aeruginosa was measuring MICs of 4.15 +/- 0.03, 4.23 +/- 0.02, and 4.43 +/- 0.04 mu g mL-1, whereas 5a and 6d displayed excellent activity against B. subtilis with MICs 5.33 +/- 0.01, and 3.91 +/- 0.02 mu g mL-1 respectively. In particular, the prepared scaffolds 5b, 6d, and 5a showed remarkable antifungal activity against C. albicans with MICs 4.18 +/- 0.04, 4.70 +/- 0.01, and 5.10 +/- 0.02 mu g mL-1 accordingly. Initially, all of the synthesized compounds were evaluated in silico docking against antifungal drug candidate (5TZ1) and further evaluated for their ADMET properties by SwissADME and ADMETlab2.0. The computational modelling of benzoxazinone-1,2,3-triazole 6d revealed better hydrogen bonding patterns with amino acids Arg381(A) [O2-NH] (2.98 & Aring;), Try132(A) [N22-OH] (2.61 & Aring;), Ile471(A) [O28-NH] (3.16 & Aring;) and has predicted to show remarkable affinity with C. albicans. Theoretical evaluation provides an insight about ligand interaction with proteins, highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), electronegativity, hardness, softness, electrophilicity and neucleophilicity of the ligands via molecular docking and density functional theory (DFT) studies; this presents probable evidence for the biological activity of the derivatives.