Two new casbane diterpenoids from the roots of Euphorbia pekinensis

Abstract

From the roots of Euphorbia pekinensis, two new casbane diterpenoids, named pekinenins A (1) and B (2), were isolated. Their structures were elucidated as 18-hydroxy-1βH,2αH-casba-3E,7E,11E-trien-5-one (1), 5α-methoxy-1βH,2αH-casba-3Z,7E,11E-trien-18-oic acid (2) by a combination of 1D and 2D NMR spectroscopy and mass spectrometry. In the cytotoxicity assay of the two new compounds against Hela, MCF-7, and C6 human cancer cell lines, compound 1 showed moderate cytotoxic activity against two human cancer cell lines, Hela and C6, with IC₅₀ values of 42.97 and 50.00 μM, respectively.

Keywords:

• Euphorbia pekinensis Rupr
• pekinenin A
• pekinenin B
• casbane diterpenoids

Acknowledgements

This work was financially supported by National Major Special Science and Technology Project (2010ZX09401-304-104A). We are grateful to Prof. Jincai Lu for identification of the plant material.