Vetiverianines A, B, and C: Sesquiterpenoids from Vetiveria zizanioides Roots

Three new sesquiterpenoidsvetiverianines A (1), B (2), and C (3)and a known eudesmane sesquiterpenoid (4) were isolated from the roots of Vetiveria zizanioides. Vetiverianine A (1) has a unique carbon framework comprising a rigid tricyclic ring system. Vetiverianines B (2) and C (3) are new eremophilane sesquiterpenoids. The structures of sesquiterpenoids 1–3, including the absolute configurations, were determined by NMR spectroscopic, X-ray crystallography, and vibrational circular dichroism data analysis. Vetiverianine C (3) exhibited weak cytotoxic activity against HL-60 cells.从香根草（Vetiveria zizanioides）的根部分离得到3个新的倍半萜类化合物（sesquiterpenoids）——香根草碱A（vetiverianine A，1）、香根草碱B（vetiverianine B，2）与香根草碱C（vetiverianine C，3），以及1个已知的桉叶烷型倍半萜（eudesmane sesquiterpenoid，4）。香根草碱A（1）具有独特的碳骨架，该骨架包含刚性三环环系（tricyclic ring system）。香根草碱B（2）与香根草碱C（3）为新型艾里莫芬烷型倍半萜（eremophilane sesquiterpenoids）。通过核磁共振波谱法（NMR spectroscopic）、X射线晶体衍射（X-ray crystallography）以及振动圆二色谱（vibrational circular dichroism）数据分析，确定了化合物1~3的结构，包括其绝对构型。香根草碱C（3）对HL-60细胞系（HL-60 cells）表现出微弱的细胞毒活性（cytotoxic activity）。