Two new daphnane diterpenes from the roots of Stelleropsis tianschanica.

Two new daphnane diterpenes named tianchaterpenes A and B were isolated from the roots of Stelleropsis tianschanica. Their structures were elucidated on the basis of chemical and spectral analysis, including 1D, 2D NMR analyses and HRESIMS. Compounds 1 and 2 were evaluated for their cytotoxic activities against HeLa and HCT-8 cell lines. The results showed that all compounds displayed weak cytotoxicities to the HeLa cells and were inactive to the HCT-8 cells.