The antioxidant activities, inhibitory effects, kinetics, and mechanisms of artocarpin and α-mangostin on α-glucosidase and α-amylase.

This study investigated the antioxidant activities, enzyme inhibitory activities and the interaction mechanisms of artocarpin and α-mangostin on α-amylase and α-glucosidase. Results showed that artocarpin and α-mangostin had obvious antioxidant activities and inhibitory activities on α-glucosidase and α-amylase. The inhibitions of the two compounds on α-glucosidase were reversible and non-competitive according to the kinetics studies. Fluorescence intensity measurements indicated that the interaction mechanisms between the inhibitors and the two enzymes were static processes. Isothermal titration calorimetry (ITC) analysis showed that the bindings between the inhibitors and the enzymes complex were all spontaneous. The main driving forces between α-mangostin and artocarpin with α-glucosidase might be hydrogen bonds and electrostatic interactions, respectively. While the forces between the two inhibitors and α-amylase might be hydrophobic interactions. Furthermore, molecular docking results showed that artocarpin and α-mangostin could bind to the allosteric site of the two enzymes, except for artocarpin in the active site pocket of α-amylase. All the results indicated that artocarpin and α-mangostin might be promising candidates for hypoglycemic functional products.