One new cembranoid diterpene from gum resin of Boswellia carterii

This study aims to study the chemical components from the gum resin of Boswellia carterii. Five cembranoid diterpenes were isolated from the gum resin of B. carterii by various of column chromatographies including silica gel, Sephadex LH-20, and semi-preparative HPLC. Their structures were identified on the basis of physicochemical properties, mass spectrometry(MS), nuclear magnetic resonance(NMR), Ultraviolet(UV) and infrared(IR) spectroscopic data. These compounds were identified as(1S,2E,4R,5S,7E,11E)-4-methoxy-5-hydroxycembrane(1),(1R~*,4R~*,5E,8E,12E,15E)-4-hydroxycembra-5,8,12,15-tetraene(2), cembrene A(3),(3S,4S,7R)-4-hydroxycembrane(4), and pavidolide D(5). Compound 1 was a new compound. Compounds 2, 4, and 5 were obtained from the gum resin of B. carterii for the first time. Compound 2 showed weak inhibition on the human liver cancer cell line HepG2.