α-Glucosidase inhibitors from Chinese bayberry (Morella rubra Sieb. et Zucc.) fruit: molecular docking and interaction mechanism of flavonols with different B-ring hydroxylations.

ABSTRACT: Inhibition of α-glucosidase alleviates postprandial high glycemic levels in diabetic or prediabetic population. In Chinese bayberry fruit, myricetin, quercetin and kaempferol are main flavonols, which differ only in their hydroxylation on the B-ring. Kaempferol (4'-OH) showed high IC₅₀ (65.36 ± 0.27 μmol L^-1) against α-glucosidase, while quercetin (3',4'-OH) exhibited stronger inhibition (46.91 ± 0.54 μmol L^-1) and myricetin (3',4',5'-OH) possessed the strongest inhibitory activity (33.20 ± 0.43 μmol L^-1). Molecular docking analysis illustrated that these flavonols could insert to the active cavity of α-glucosidase. Adjacent hydroxyl groups at B-ring of myricetin and quercetin positively contributed to form hydrogen bonds that were important to t

SUBMITTER: Liu Y 

PROVIDER: S-EPMC9055920 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature