Hepatoprotective Tetrahydrobenzocyclooctabenzofuranone Lignans from Kadsura longipedunculata

Three new tetrahydrobenzocyclooctabenzofuranone lignan glucosides, longipedunculatins A–C ( 1 – 3 ), a new dibenzocyclooctadiene lignan glucoside, longipedunculatin D ( 4 ), a new dibenzocyclooctadiene lignan ( 5 ), five new tetrahydrobenzocyclooctabenzofuranone lignans ( 6 – 10 ), and two new simple lignans ( 11, 12 ) were isolated from the roots of Kadsura longipedunculata. Their structures and absolute configurations were established using a combination of MS, NMR, and experimental and calculated electronic circular dichroism data. Compound 7 showed moderate hepatoprotective activity against N -acetyl- p -aminophenol-induced toxicity in HepG2 cells with a cell survival rate at 10 μM of 50.8%. Compounds 2, 7, and 12 showed significant in vitro inhibitory effects with an inhibition rate of 55.1%, 74.9%, and 89.8% on nitric oxide production assays at 10 μM.