Saussurenoids A–G, seven new sesquiterpenoids from Saussurea medusa Maxim

Seven new sesquiterpenoids (1–7), including two rare botryane-type sesquiterpenoids (1 and 2), and five megastigmane sesquiterpenoids and its glycoside (3–7) were isolated from the whole plants of Saussurea medusa Maxim. Their structures were elucidated based on extensive spectroscopic methods, electric circular dichroism (ECD) calculations and the single-crystal X-ray diffraction analysis. The absolute configuration of the 10,11-diol moiety in compound 6 was determined by observing the circular dichroism induced after addition of dimolybdenum tetracetate [Mo2(OAc)4] in DMSO solution. Compound 2 displayed modest cytotoxic effects against A549 and HL-60 cell lines with IC50 values of 5.6 ± 1.0 and 7.4 ± 1.2 μM, respectively. [Display omitted]