Triterpene saponins from Eryngium kotschyi

Four oleanane-type saponins (1-4) were isolated from the roots of Eryngium kotschyi. Their structures were established by extensive spectroscopic interpretation. Two of them possessed unusual structures: the aglycon of 3 is a triacetylated derivative of oleanane-type skeleton with a ketone function at the C-16 position, and 4 is a glycoside of a 17,22-seco-oleanolic acid, which might be a chemotaxonomic marker of the Apiales order.