Schilancitrilactones A–C: Three Unique Nortriterpenoids from Schisandra lancifolia

Three unique nortriterpenoids, schilancitrilactones A–C (1–3), were isolated from the stems of Schisandra lancifolia. Compound 1 possesses a 5/5/7/5/5/5-fused hexacyclic ring system with a C29 backbone, while 2 and 3 feature a C27 skeleton with a 5/7/5/5/5-fused pentacyclic ring system. Their absolute stereochemistries were established by CD and single-crystal X-ray diffraction experiments. Compound 3 showed anti-HIV-1 activity with an EC50 value of 27.54 μg/mL, and 1 exhibited antifeedant activity at 15.73 μg/cm2.从长梗五味子（Schisandra lancifolia）的茎部分离得到3种独特的降三萜类（nortriterpenoids）化合物，即schilancitrilactones A–C（1~3）。化合物1具有以C29为骨架的5/5/7/5/5/5稠合六环体系，而化合物2与3则拥有以C27为骨架的5/7/5/5/5稠合五环体系。其绝对立体构型通过圆二色谱（CD）与单晶X射线衍射实验得以确证。化合物3表现出抗HIV-1活性，半数有效浓度（EC50）为27.54 μg/mL；化合物1则在15.73 μg/cm²的浓度下展现出拒食活性。