Neolignan glycosides from Symplocos caudata

Four optical isomers of 7,9,9′-trihydroxy-3,3′-dimethoxy-8- O-4′-neolignan-4- O-β- d-glucopyranoside, a lignan lactone glycoside, and a phenylpropanoid glycoside were isolated 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 (7 S,8 S)- threo-7,9,9′-trihydroxy-3,3′-dimethoxy-8- O-4′-neolignan-4- O-β- d-glucopyranoside ( 1), (7 R,8 R)- threo-7,9,9′-trihydroxy-3,3′-dimethoxy-8- O-4′-neolignan-4- O-β- d-glucopyranoside ( 2), (7 R,8 S)- erythro-7,9,9′-trihydroxy-3,3′-dimethoxy-8- O-4′-neolignan-4- O-β- d-glucopyranoside ( 3), (7 S,8 R)- erythro-7,9,9′-trihydroxy-3,3′-dimethoxy-8- O-4′-neolignan-4- O-β- d-glucopyranoside ( 4), 8 R,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.