Isolation and characterization of xuetonlignans L-P, previously undescribed spirobenzofuranoid dibenzocyclooctadiene lignans from the fruits of Kadsura heteroclita.

Five previously undescribed spirobenzofuranoid dibenzocyclooctadiene lignans, xuetonlignans L-P (1-5), and three known dibenzocyclooctadiene lignans (6-8) were isolated from the fruits of Kadsura heteroclita. Their structures were elucidated by analysis of HR-ESI-MS, NMR spectroscopy, CD spectra and single-crystal X-ray structure determination. The hepatoprotective activity against H2O2-induced toxicity in HepG2 cells and anti-inflammatory activity against NO (nitric oxide) were performed. Compounds 4 and 8 showed potent hepatoprotective activity against H2O2-induced toxicity in HepG2 cells compared to the positive control, bicyclol. Furthermore, compound 6 significantly inhibited the NO production in LPS-induced RAW264.7 cells at a concentration of 20 μM.