Structure elucidation and NMR spectral assignments of three new lignan glycosides from Akebia trifoliata

Three new lignan glycosides (1–3) were isolated from the stems of Akebia trifoliata . Their structures were elucidated as (7 R ,8 R ,7′ R ,8′ R )3,3′,5,5′tetramethoxy‐4,4′dihydroxy‐7,9′:7′,9‐diepoxylignan‐4‐ O ‐β‐ D ‐glucopyranoside (1), (7 S ,8 S ,8′ R )‐4,4′,9‐trihydroxy‐3,3′,5,5′‐tetramethoxy‐7,9′‐epoxylignan‐7′‐one 9‐ O ‐β‐ D ‐glucopyranoside (2), (7 R ,8 R ,8′ S )‐4,4′,9‐trihydroxy3,3′,5,5′‐tetramethoxy‐7,9′‐epoxylignan‐7′‐one 9‐ O ‐β‐ D ‐glucopyranoside (3) by spectral analyses, primarily NMR, MS and CD. The NMR assignments for the compounds were carried out using 1 H, 13 C, DEPT, COSY, HSQC, HMBC and ROESY NMR experiments. Copyright © 2007 John Wiley & Sons, Ltd.