Cytotoxicity-guided isolation of elatostemanosides I–VI from Elatostema tenuicaudatum W. T. Wang and their cytotoxic activities†

Abstract

Elatostema tenuicaudatum W. T. Wang, a medicinal plant traditionally utilized in herbal remedies, was explored for its cytotoxic properties. Bioassay-guided fractionation led to the discovery of six novel compounds, designated as elatostemanosides I–VI, with their structures elucidated through advanced spectroscopic methods and DP4+ analysis. Among these, compounds 2, 5, and 6 demonstrated moderate cytotoxicity against the human liver cancer cell line HepG2, exhibiting IC₅₀ values of 18.2 ± 2.1, 32.1 ± 0.4, and 57.6 ± 1.3 µM, respectively. Notably, compound 6 also displayed significant activity against the human breast cancer cell line HCC1806, with an IC₅₀ value of 35.4 ± 0.3 µM. Mechanistic studies revealed these compounds induced apoptosis by modulating the Bax/Bcl-2 ratio. Furthermore, structure–activity relationship (SAR) analysis underscored the importance of specific functional groups in mediating cytotoxic effects.