Abstract
A new eremophilane norsesquiterpenoid (1), together with a known eremophilane sesquiterpenoid (2), was isolated from the leaves of Ligularia virgaurea. The structure of 1 was elucidated by a combination of spectroscopic analysis (IR, 1D NMR, 2D NMR, and HR-ESI-MS), and its absolute configuration was determined by a single-crystal X-ray diffraction experiment (with copper radiation). The known compound 2 was identified by comparison of its physical and spectral data with those reported in the literature. Compound 1 was assayed for its cytotoxic activities against human cervical carcinoma cell (HeLa) and human small cell lung cancer cell (NCI-446) lines.
Acknowledgements
The authors are grateful to the National Natural Science Foundation of China (Nos. 21402075 and 21102065), the Natural Science Foundation of Gansu Province, China (No. 1208RJYA029), and the Fundamental Research Funds for the Central Universities (No. lzujbky-2013-72) for financial support to this research.