Stelleraguaianone B and C, two new sesquiterpenoids from Stellera chamaejasme L.

Two new sesquiterpenoids were isolated from Stellera chamaejasme L., known as the traditional Chinese herb ‘Rui Xiang Lang Du’. The compounds were elucidated as stelleraguaianone B (1) and C (2) by comprehensive spectroscopic analysis, including 1D and 2D NMR as well as HRESIMS, and by comparing their NMR data with known compounds. In addition, the structure of 1 was further confirmed by single-crystal X-ray diffraction analysis. Both the compounds were evaluated for their cytotoxicity on common tumour cell lines in vitro, which revealed that compound 1 exhibits cytotoxic activity on A549 cells, while 2 has no activity.