Antioxidant and enzyme inhibition activities and chemical profiles of Polygonum sachalinensis F.Schmidt ex Maxim (Polygonaceae).

Polygonum sachalinensis is a widespread invasive plant in Europe. Chemical profiles of its different organs were studied by HPLC-UV-ESI/MS. Seven major constituents quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-arabinopyranoside, lapathoside D, N-trans-feruloyltyramine, lapathoside C, hydropiperoside, and vanicoside B were isolated and identified. The free radical-scavenging, alpha/beta-glucosidase, and acetylcholinesterase inhibitory activities of crude MeOH extracts and isolated compounds were studied. The structure-activity relationships were discussed. The chemical profiles revealed flavonoids and phenylpropanoids are the major compounds of all the organs of this plant. Quercetin-3-O-arabinopyranoside, lapathoside D, N-trans-feruloyltyramine, lapathoside C and hydropiperoside were isolated from this species for the first time. In the alpha-glucosidase bioassay, quercetin-3-O-beta-D-galactopyranoside, lapathoside D and N-trans-feruloyltyramine demonstrated stronger activities than the positive reference acarbose. The trend in scavenging power showed no relation to enzyme inhibition in the test models.