Inhibitory mechanism of taxifolin against α-glucosidase based on spectrofluorimetry and molecular docking

Abstract

The α-glucosidase inhibitory activity and behavior of taxifolin was first investigated by spectrofluorimetry and molecular docking. It was found that taxifolin inhibits α-glucosidase in a competitive manner with the IC50 value of 0.16 mg/mL. The intrinsic fluorescence quenching of α-glucosidase in the presence of taxifolin was observed by the static quenching mechanism. According to the thermodynamic study, the complex of taxifolin and α-glucosidase was maintained by van der Waals and hydrogen bonding. The binding mode provided by molecular docking simulation indicated the existence of hydrogen bonding between taxifolin and the amino acid residues of α-glucosidase (Glu429, Asp 568 and Glu771), which coincided with the result of fluorescence analysis.