Norlathyrane diterpenes from the root of Euphorbia kansuensis.

ABSTRACT

Phytochemical investigation of the EtOH extract obtained from the root of the Euphorbia kansuensis Proch. grown in China resulted in the isolation of two novel norlathyrane diterpenes, named ekanpenoids A and B (1 and 2, resp.). Their structures were established by extensive 1D- and 2D-NMR spectroscopy, as well as other spectra. The isolated diterpenes exhibited potent cytotoxic activities against the HeLa and Hep-G2 cell lines with the IC50 values ranging from 3.6 to 9.7 µg/ml.