Bioactive phenylpropanoid esters of sucrose and anthraquinones from Polygonum cuspidatum.

Four new compounds including two new phenylpropanoid esters of sucrose, polygonusucroside A (1) and B (2); two new anthraquinones, 8-O-β-d-(6'-galloyl)-glucopyranoside (3) and polyanthraquinoside A (4), together with six known compounds were isolated from Polygonum cuspidatum. Their structures were established using UV, IR, HRESIMS, and NMR data. All compounds were evaluated for their α-glucosidase inhibitory activities and neuroprotective effects. Compounds 5, 7 and 9 showed significant α-glucosidase inhibitory activities with IC50 values of 27.30, 5.51, and 1.09 μmol/L, respectively (acarbose as positive control, IC50 = 6.17 μmol/L). In addition, the assessment of neuroprotective effect showed that compound 3 exhibited remarkable effect against PC12 cells injured by serum-deprivation and compounds 2, 7, and 9 exhibited moderate effects against PC12 cells injured by rotenone.