Bioactive cembrane-type diterpenoids from the gum-resin of Boswellia carterii.

Chemical examination of the gum-resin of Boswellia carterii resulted in the isolation and characterization of eighteen new cembrane-type diterpenoids, named as Boscartins P-AG (1-18) and eight known ones. Their structures were established on the basis of extensive spectroscopic (2D NMR, IR, CD, MS and X-ray) analysis in combination with modified Mosher's method. All compounds featured unusual 1,12-oxygenated tetrahydrofuran functionalities, and were evaluated for hepatoprotective activity against D-galactosamine-induced HL-7702 cell damage and cytotoxic activity against MCF-7 human breast cancer cell in vitro. Compounds 1, 6-10, 12-13, 16-17 and 21-25 (10 μM) showed some hepatoprotective activity against D-galactosamine-induced HL-7702 cell damage.