Lignan and Neolignan Glycosides from the Roots ofGlehnia littoralis

A new lignan glycoside [glehlinoside G (1)] and three new neolignan glycosides [glehlinosides H (2), I (3) and J (4)] were isolated from the roots of Glehnia littoralis. Their structures were elucidated on the basis of spectroscopic data. The above glehlinosides (1-4), together with the other lignan and neolignan glycosides (5-12) from this plant, were evaluated for their prolyl oligopeptidase inhibitory activities, and a caffeoyled lignan glycoside (glehlinoside F, 8) exhibited a noticeable activity (IC(50) = 14.5 µM).