A new oxygenated spiroketone, isodonspiroketone (1), and 4 known ones (2-5) were isolated from the whole plant of Isodon ternifolius (D.Don) Kudô. The structure of isodonspiroketone (1) was determined by nuclear magnetic resonance, mass spectroscopy, and circular dichroism spectral data. Compound 3 has not been previously isolated from I. ternifolius. Their cytotoxic activities were evaluated against A549, HepG2, and MDA-MB-231 cancer cell lines in vitro. New compound (isodonspiroketone, 1) showed moderate cytotoxic activities against A549, HepG2, and MDA-MB-231 cancer cell lines with half-maximal inhibitory concentration values of 23.84 ± 2.73, 27.77 ± 3.01, and 17.26 ± 1.61 μM, respectively; meanwhile, the others were inactive.

从整个Isodon ternifolius（D.Don）Kudô的植物中分离出一种新的含氧螺酮（isodonspiroketone）（1）和4种已知的螺酮（2-5）。通过核磁共振，质谱和圆二色性光谱数据确定异戊酮（1）的结构。化合物3先前尚未从ternifolius中分离出来。在体外评估了它们针对A549，HepG2和MDA-MB-231癌细胞系的细胞毒性活性。新化合物（isodonspiroketone，1）显示出对A549，HepG2和MDA-MB-231癌细胞系的中等细胞毒性活性，半数最大抑制浓度分别为23.84±2.73、27.77±3.01和17.26±1.61μM; 同时，其他人则不活跃。