Discovery of vitexin as a novel α‐glucosidase inhibitors in mulberry (Morus alba L.) by untargeted metabolomics combined with molecular docking: A comprehensive study from mechanism to synergy effects

Abstract

Mulberry (Morus alba L.) leaf can effectively inhibit the digestion of starchy foods, and α‐glucosidase (AG) is its main target. This study employed an untargeted metabolomics approach combined with molecular docking to identify AG inhibitors. Subsequently, inhibition kinetics, fluorescence spectroscopy, and interaction force analysis were utilized to investigate the inhibitory mechanism. Results indicated that vitexin exhibited significant reversible inhibition of AG through competitive inhibition, with an IC50 value of 105.50 ± 1.30 μg/mL. Molecular docking revealed hydrogen bonding as the main interaction force between vitexin and AG, and quenching mechanism analysis showed that they underwent static quenching driven by entropy. The results of the combined experiment showed that 1‐deoxynojirimycin (DNJ), a known bioactive component in mulberry, has a synergistic effect of inhibiting AG activity with vitexin. This study elucidates the potential mechanism of vitexin in inhibiting AG activity and provides theoretical evidence for utilizing vitexin‐DNJ complexes as functional components of AG inhibitors.