Synthesis of novel 4-hydroxycoumarin derivatives: evaluation of antimicrobial, antioxidant activities and its molecular docking studies

A series of novel 4-hydroxycoumarin derivatives 4a-n were synthesized by treating 2-(2-oxo-2H-chromen-4-yloxy)acetic acid 3 with various amines. Acid 3 was obtained from the hydrolysis of corresponding ester 2 which was prepared from 4-hydroxycoumarin 1 and ethyl bromoacetate. All synthesized compounds 4a-n were characterized using spectral techniques. The synthesized compounds 4a-n were evaluated for their antimicrobial and total antioxidant activity using in vitro well diffusion method and phosphomolybdenum method, respectively. Amongst all the compounds, 4c has shown potential antimicrobial and antioxidant activity against the standard. All compounds have exhibited good binding energies from -4.46 to -5.70 kcal/mol against 24-kDa DNA gyrase B fragment from E. coli (PDB ID-1KZN) in molecular docking study and amongst them 4c has shown maximum binding energy.