Structurally diversified diterpenoids from Euphorbia dracunculoides

Extensive phytochemical investigation of the aerial parts of Euphorbia dracunculoides led to the isolation of 19 structurally diversified diterpenoids with five different carbon skeletons, including six new lathyrane glycosides (1-6), three new cyclomyrsinanes (7-9), three new premyrsinanes (10-12), and one new 10,18-dihydromyrsinane (13). Their structures were elucidated by means of extensive spectroscopic analysis, and the structure of 7 was further confirmed by X-ray crystallography. Compounds 1-6 are the first examples of C-17-glycosylated lathyrane diterpenoids. Selected isolates were evaluated for their cytotoxicity against five cancer cell lines. Only the tiglianes exhibited moderate activity. (C) 2015 Elsevier Ltd. All rights reserved.