Jatrophane diterpenoids from Euphorbia helioscopia and their lipid-lowering activities.

The phytochemical study of Euphorbia helioscopia led to the isolation of 33 jatrophane diterpenoids (1-33), of which six (1-6) were new. This small jatrophane library was established to screen for potential lipid modulators. LDL-Uptake screening assay demonstrated that most of them improved LDL-Uptake rate in HepG2 cells, with compounds 16, 21 and 26 exhibiting more outstanding effects. Further exploration found that these three compounds could increase LDLR protein level in HepG2 cells dose-dependently. SAR studies suggested that substituted patterns of C-9, steric hindrance between C-14 and C-15, and the long conjugated fragment from C-5 to the carbonyl (C-9) were essential for the activity. Moreover, compound 21, a relatively abundant chemical in E. helioscopia, showed remarkable lipid-lowering effect in vivo, which makes it a promising lead for development of new lipid-lowering agents.