Commiphoranes A-D, Carbon Skeletal Terpenoids from Resina Commiphora.

Commiphoranes A-D (1-4), four novel aromatic terpenoids with unprecedented carbon skeletons, were isolated from Resina Commiphora. Their structures were identified by spectroscopic and crystallographic methods. Compounds 1 and 2 are dinorditerpenoids characteristic of a 6/6/6/6 ring system. In contrast, compounds 3 and 4 are sesquiterpenoids possessing a 5/6/7 backbone. Biological evaluation reveals that 3 could significantly attenuate overproduction of fibronectin, collagen I, and α-SMA in TGF-β1-induced rat renal proximal tubular cells.