Abietane Diterpernoids from the Roots of Euphorbia ebracteolata

A new ent-abietane diterpernoid,named ebracteolata D(1),along with 11 known analogues,was isolated from the roots of Euphorbia ebracteolata Hayata.The structure of 1 was elucidated on the basis of spectroscopic analysis and molecular modeling.Cytotoxicity of compounds 1-12 was evaluated as well as the effect on the NF-κB pathway.Among them,compound 12,jolkinolide B,displayed broad inhibitory effects against proliferation of tumor cell lines.Mechanistic studies indicated that the compound 12 can inhibit TNF-αinduced NF-κB activation,thereby inducing tumor cell apoptosis.