Neolignan glycosides from Symplocos caudata

A phytochemical investigation of the roots of Symplocos caudata Wall (Symplocaceae) resulted in isolation and characterization of four optical isomers of a neolignan glycoside (1–4), a lignan lactone glycoside (5), a phenylpropanoid glycoside (6), as well as two known compounds (7, 8). Their structures were elucidated as (7S,8S)-threo-7,9,9′-trihydroxy-3,3′-dimethoxy-8-O-4′-neolignan-4-O-β-d-glucopyranoside (1), (7R,8R)-threo-7,9,9′-trihydroxy-3,3′-dimethoxy-8-O-4′-neolignan-4-O-β-d-glucopyranoside (2), (7R,8S)-erythro-7,9,9′-trihydroxy-3,3′-dimethoxy-8-O-4′-neolignan-4-O-β-d-glucopyranoside (3), (7S,8R)-erythro-7,9,9′-trihydroxy-3,3′-dimethoxy-8-O-4′-neolignan-4-O-β-d-glucopyranoside (4), 8R,8′R-matairesinol-4-O-β-d-xylopyranosyl-(1 → 2)-O-β-d-glucopyranoside (5), 1-O-[β-d-xylopyranosyl-(1 → 6)-O-β-d-glucopyranosyl]-2,6-dimethoxy-4-propenyl-phenol (6), matairesinoside (7), and (R)-1-O-(β-d-glucopyranosyl)-2-[2-methoxy-4-(ω-hydroxypropyl)-phenoxyl]-propan-3-ol (8) on the basis of spectroscopic data (1D and 2D NMR, MS and CD) and chemical evidence.