Tigliane Type Diterpene-esters with Epstein–Barr Virus-inducing Activity fromSapium sebiferum

Abstract
Three Epstein-Barr virus activating principles have been isolated from the leaves of Sapium sebiferum (Euphorbiaceae), which is one of common roadside and garden trees in Japan. By chemical and spectroscopic evidence they were identified as tigliane type diterpene-esters with the structures of 1,2 and 3.1 and 2 strongly induced an early antigen of the virus in a Raji cell, while 3 did so weakly. The activity of some derivatives of 2 are also discussed.