Hepatoprotective TetrahydrobenzocyclooctabenzofuranoneLignans 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.