Euphorstranoids A and B, two highly rearranged ingenane diterpenoids from Euphorbia stracheyi: structural elucidation, chemical transformation, and lipid-lowering activity

Euphorstranoids A (1) and B (2), two highly rearranged ingenane diterpenoids with an unusual 5/6/7/3 carbon ring system, were isolated from Euphorbia stracheyi. Their structures were determined by a combination of spectral, chemical, and X-ray diffraction methods. The plausible biosynthetic pathway of 1 and 2 was proposed and chemically mimicked. Compounds 1 and 2 significantly inhibited the triglyceride (TG) level in 3T3-L1 adipocytes via retarding cell adipogenesis at the early stage.