Abstract:Phenolic compounds in mulberry leaves can reduce the digestion and absorption of fat to achieve weight loss, but the mechanism of their interaction with lipase remains to be clarified. In this study, the inhibitory effect of 12 phenolic compounds in mulberry leaves on lipase was investigated through lipase activity experiment in vitro. It was found that hypericin and rutin with the same parent nucleus structure had better inhibitory activity on lipase. The inhibition mechanism of hypericin and rutin on lipase was studied by fluorescence spectrum analysis, FTIR analysis and molecular docking simulation. The fluorescence spectra showed that hypericin and rutin had static quenching effect on lipase, and the binding constant of hypericin and lipase was greater. FTIR analysis showed that the combination of hypericin and rutin with lipase changed the secondary structure of lipase such as β-folding, β-turning and random curling. Molecular docking simulation analysis showed that hypericin and rutin bound to lipase through hydrogen bonding and hydrophobic action, thus inhibiting enzyme activity, and hypericin bound to lipase more stably. This study revealed the inhibition mechanism of mulberry leaf polyphenols on lipase, and laid a theoretical foundation for the research and development of antiobesty functional food of mulberry leaf.
