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-beta-d-glucopyranoside (1), (7R,8R)-threo-7,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-4-O-beta-d-glucopyranoside (2), (7R,8S)-erythro-7,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-4-O-beta-d-glucopyranoside (3), (7S,8R)-erythro-7,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-4-O-beta-d-glucopyranoside (4), 8R,8'R-matairesinol-4-O-beta-d-xylopyranosyl-(1-->2)-O-beta-d-glucopyranoside (5), 1-O-[beta-d-xylopyranosyl-(1-->6)-O-beta-d-glucopyranosyl]-2,6-dimethoxy-4-propenyl-phenol (6), matairesinoside (7), and (R)-1-O-(beta-d-glucopyranosyl)-2-[2-methoxy-4-(omega-hydroxypropyl)-phenoxyl]-propan-3-ol (8) on the basis of spectroscopic data (1D and 2D NMR, MS and CD) and chemical evidence.