Investigation of the structure-activity relationship of resveratrol and its glycosylated and acylated derivatives in relation to their α-glucosidase inhibitory activities

Resveratrol with excellent α-glucosidase inhibitory activity is widely distributed in foods. However, in-depth research on the effects of glycosylation and acylation of resveratrol on its α-glucosidase inhibitory activity is limited. In the present study, we investigated the structure-activity relationship of resveratrol, resveratrol-4'-O-glucoside, resveratrol 4'-O-(6''-O-galloyl)-glucoside and resveratrol 4'-O-(2''-O-galloyl)-glucoside against α-glucosidase. Notably, C-4' glycosylation enhanced potency, and subsequent galloyl acylation further improved activity with acylation at C-6'' slightly outperforming that at C-2''. Spectroscopic analyses confirmed conformational changes in the enzyme upon binding. Molecular docking showed C-4' glycosylation led to the formation of additional hydrogen bonds with α-glucosidase, and subsequent acylation further increased their number. Molecular dynamics simulations showed resveratrol 4'-O-(6''-O-galloyl)-glucoside, owing to its lower steric hindrance than resveratrol 4'-O-(2''-O-galloyl)-glucoside, penetrates more deeply into the active-site pocket of α-glucosidase, resulting in a more stable binding. These findings may provide theoretical basis for the development of resveratrol and its derivatives in functional foods.