A new lignan glycoside from Forsythia suspensa

Phytochemical investigation on Forsythia suspensa (Thunb.) Vahl afforded ten compounds, including five lignan glycosides and five phenylethanoid glycosides. The compounds were isolated by using HP-20 macroporous resin, silica gel, octadecyl silica gel (ODS), size exclusion chromatography resin HW-40 chromatography, and preparative HPLC. The structures were established through application of extensive spectroscopic methods, including ESI-MS, 1D-and 2D-NMR spectroscopy. They were identified as forsythialanside E (1), 8'-hydroxypinoresinol-4'-O-β-D-glucoside (2), 8'-hydroxypinoresinol (3), lariciresinol-4'-O-β-D-glucoside (4), lariciresinol-4-O-β-D-glucoside (5), forsythoside H (6), forsythoside I (7), forsythoside F (8), plantainoside B (9), and plantainoside A (10). Compound 1 was a new lignan glycoside.