An isopimarane diterpene from Euphorbia ebracteolata Hayata.

From the ethanolic extract of the roots of Euphorbia ebracteolata Hayata four compounds were isolated. They are 24-methylenecycloartanone, tirucallol, procesterol and a new isopimarane diterpene, namely yuexiandajisu C. The structure of yuexiandajisu C was elucidated by spectral analysis. The bioassay in vitro showed yuexiandajisu C exhibited immunomodulatory activity.