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 H2O2-induced injury in human neuroblastoma SH-SY5Y cell lines. Cell viability was remarkably reduced to 52.33% in H2O2-treated cells. Compounds 5-7 exhibited moderate neuroprotective activities at 50 μM, with cell viability of 64.84%, 67.34% and 63.73%, respectively.
Keywords: Neuroprotective effects; Schinortriterpenoids; Schisandra chinensis (Turcz.) Baill.; Schisandraceae.