Anti-inflammatory Compounds from the Leaves of Ailanthus altissima

In our ongoing search for biological components from the Korea endemic plants, the MeOH extract of Ailanthus altissima leaves (Simaroubaceae) showed cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) dual inhibitory activity by assessing their effects on the production of prostaglandin D-2 (PGD(2)) and leukotriene C-4 (LTC4) in mouse bone marrow-derived mast cells (BMMCs). In further study, eight compounds, squalene (1), P-sitosterol (2), scopoletin (3), quercetin (4), luteolin (5), astragalin (6), scopolin (7), and daucosterol (8) were isolated, the chemical structures were elucidated on the basis of physicochemical and spectroscopic data and by comparison with those of published literatures. Among the compounds, 2, 4, and 5 strongly inhibited both the COX-2-dependent PGD(2) generation with IC50 values of 2.6, 7.3 and 2.5 mu M, respectively and the generation of LTC4 in the 5-LOX dependent phase with IC50 values of 2.0, 5.1 and 1.8 mu M, respectively, which suggest that the anti-inflammatory activity of A. altissima might occur in part via the inhibition of both PGD(2) and LTC4 generation by 2, 4 and 5.