Three new schinortriterpenoids from the leaves of Schisandra chinensis (Turcz.) Baill.

Three undescribed schinortriterpenoids, schinensilactones D-F ( 1-3 ), together with five known ones, namely, wuweizidilactone A ( 4 ), wuweizidilactone C ( 5 ), wuweizidilactone F ( 6 ), wuweizidilactone J ( 7 ) and wuweizidilactone N ( 8 ), were isolated from the leaves of Schisandra chinensis (Turcz.) Baill. The structures of new compounds were established by analysis of their spectroscopic data including MS, IR, 1D- and 2D-NMR spectra. The absolute configuration of 1 was confirmed by single-crystal X-ray diffraction and calculated electronic circular dichroism (ECD) spectra. All compounds were evaluated for their neuroprotective effects against H 2 O 2 -induced injury in human neuroblastoma SH-SY5Y cell lines. Cell viability was remarkably reduced to 52.33% in H 2 O 2 -treated cells. Compounds 5 - 7 exhibited moderate neuroprotective activities at 50  μ M, with cell viability of 64.84%, 67.34% and 63.73%, respectively.