Green synthesis of chromonyl chalcone and pyrazoline as potential antimicrobial agents – DFT, molecular docking and antimicrobial studies

Abstract

The synthesis of biologically important chromonyl chalcone and pyrazoline derivative, via an impressive as well as an eco-friendly green approach, using LaCl3/nano SiO2 catalyst under solvent-free heating method has been discussed here. In this methodology, chromonyl chalcone prepared from 3-formylchromone and 5-acetylthiobarbituric acid by Claisen Schmidt condensation reaction was further used as an intermediate for the synthesis of a novel bioactive pyrazoline derivative. The novel compounds structures were established by FTIR, NMR and mass spectroscopic techniques. Antimicrobial activities were assessed for compounds against a set of bacterial and fungal strains using disk diffusion method, which revealed compounds as good antibacterial and antifungal agents. Geometry optimizations of newly synthesized compounds have been performed on DFT level of theory by the B3LYP acting along with Gaussain 16, revision B.01 to calculate the geometric and electronic structure parameters. The molecular docking study was carried out using the structure of DNA bacterial gyrase with newly synthesized chromone-based pharmacophore scaffolds.