Heliosterpenoids A and B two Novel Jatrophane-Derived Diterpenoids with a 5/6/4/6 Ring System from Euphorbia helioscopia

摘要

Heliosterpenoids A and B (>1 and >2), two unprecedented jatrophane-derived diterpenoid esters with a novel 5/6/4/6-fused tetracyclic ring skeleton, were isolated from the whole plants of Euphorbia helioscopia. The structures of >1 and >2 were elucidated by extensive spectroscopic methods and electronic circular dichroism (ECD) analyses. The plausible biogenetic pathways of >1 and >2 were postulated. >1 and >2 were found to be potent inhibitors of P-glycoprotein (ABCB1) and >1 also exhibited cytotoxicity against MDA-MB-231 cell lines.