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.