Torachrysone-8-O-b-D-glucoside shows alpha-glucosidase inhibitory activities, it may be used for the management of type 2 diabetes.

A new kind of in vitro α±-glucosidase inhibition assay based on using maltose as the substrate was developed, and this new established method was used to determine the α±-glucosidase inhibitory activities of Polygonum multiflorum and four anthraquinone compounds. As a result, Polygonum multiflorum showed 50% α±-glucosidase inhibition at the concentration of 0.0032 mg mL-1 and four anthraquinone compounds including emodin, aloe-emodin, physcion and rhein showed strong α±-glucosidase inhibitory activities with IC50 values ranging from 4.12 μM to 5.68 μM, respectively. Moreover, the centrifugal ultrafiltration with LC-ESI-MSn was used to screen and identify active α±-glucosidase inhibitors from Polygonum multiflorum extract and nine small-molecule active compounds were successfully identified as potential α±-glucosidase inhibitors.