ABSTRACT
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.