Two new sesquiterpenoid glycosides from the leaves of Lycium barbarum

Two new sesquiterpenoid glycosides, lyciumionosides A-B (1-2), together with four known compounds (3-6), were isolated from the leaves of Lycium barbarum. Their structures were mainly established on the basis of MS, 1D and 2D NMR spectroscopic techniques. The antiproliferative activities of compounds 1-5 were evaluated. Compound 1 showed highest inhibitory activity against A549 cells with IC50 value of 32.6 +/- 2.6 mu M, compound 3 showed highest inhibitory activity against PC-3 cells with IC50 value of 36.0 +/- 2.9 mu M, and compound 5 exhibited highest inhibitory activity against HeLa cells with IC50 value of 32.3 +/- 4.2 mu M.