This study was conducted to investigate the chemical constituents of Piper wallichii(Miq.) Hand.-Mazz. and evaluate their biological activity. Compounds were isolated by various column chromatographic methods, and their structures were elucidated on the basis of physical characteristics and spectral data. The 1, 1-diphenyl-2-picrylhydrazyl(DPPH)-scavenging activity and acetylcholinesterase(AChE)-inhibitory activity of the compounds were evaluated. Five compounds were obtained and identified as 8-C-β-D-glucopyranosylkaempferol-3-O-β-D-glucopyranoside(1), 1, 2-dihydro-6,8-dimethoxy-7-hydroxy-1-(3, 5-dimethoxy-4-hydroxyphenyl)-N1, N2-bis-[2-(4-hydroxyphenyl)ethyl]-2, 3-naphthalene dicarboxamide(2), goniothalactam(3), aristololactam A IIIa(4) and piperlonguminine(5). Compound 1 was a new flavonol C-glycoside, 2 was a rare lignanamide, which was isolated from the family Piperaceae for the first time, and compound 3 was isolated from this plant for the first time. Among them, 2 showed potent DPPH-scavenging activity, with IC50 of 31.38 ± 0.97 μmol·L-1; Compounds 2, 3, and 4 showed AChE inhibitory activity at 100 μmol·L-1, with inhibition rates of 28.57% ± 1.47%, 18.48% ± 2.41% and 17.4% ± 3.03%, respectively.
