目的 研究白及Bletilla striata的低极性化学成分.方法 采用硅胶、Sephadex LH-20柱色谱和制备薄层色谱等分离纯化方法,结合高分辨质谱和核磁共振波谱分析鉴定化合物的结构;运用MTT法测定化合物的生物活性.结果 在白及化学成分研究过程中分离得到1个新的含氯甾体化合物,其结构为4-氯-β-谷甾酮(1);细胞毒活性实验表明,该化合物对正常的293A人胚肾细胞具有一定的毒性.结论 该新化合物为人工产物,为白及甾体化合物在三氯甲烷中经过长时间的强阳光照射后产生,反应机制推测为强光诱导下的自由基取代反应.

Objective To study the low polar chemical constituents from the tubers of Bletilla striata. Methods Silica gel, Sephadex LH-20 column chromatography, and preparative thin layer chromatography were used for the isolation and purification, the chemical structure was identified by the methods of high resolution mass spectrometry (HRMS) and NMR spectroscopic analyses, and the bioactivity of the compound was examined by the method of MTT. Results A new chlorinated-steroid was obtained during the study on the chemical constituents of B. striata, its structure is 4-chloro-β-sitosterone (1). In addition, the compound showed potential toxicity to 293A cells of human. Conclusion Further analysis finds that the new compound may be an artifact which is produced by exposing a steroid to strong sunlight in chloroform for a long time, and the reaction mechanism is speculated as the radical substitution reactions induced by strong light.

国家科技支撑计划(2011BAI13B05)