Cytotoxic diterpene quinones from Salvia tebesana Bunge.

A phytochemical investigation of the root extracts of Salvia tebesana Bunge led to the isolation of two new diterpenoids, tebesinone A (1) and tebesinone B (2), along with two known compounds, aegyptinone A (3) and aegyptinone B (4). The structures were established by spectroscopic analysis including 1D and 2D NMR and HRESIMS. The cytotoxic activities of the crude extracts and isolated compounds were evaluated against MCF-7, B16F10, PC-3 and C26 human cancer cell lines, in which compounds 2 and 3 showed significant cytotoxic activities (IC50 2.1-10.3 μM).