Abstract: To search for new and bioactive constituents from traditional Chinese medicines, a new steroidal saponin, named vernonioside G (1), was isolated from the roots of Vernonia cumingiana Benth. (Compositae). The structure of vernonioside G was elucidated using spectral methods, particularly two-dimensional nuclear magnetic resonance analysis. Together with the new compound, eight known compounds were also isolated and identified from the roots of V. cumingiana, among which, VE-1 (2) and 24-methylenelanost-9(11)-en-3-ol acetate (3) were assigned NMR data for the first time and compound 3 was obtained as a natural product from a plant for the first time.

Key words: Compositae, steroidal saponin, Vernonia cumingiana, vernonioside G.