A New Flavonol Glycoside from the Leaves of Boscia senegalensis

Detailed chemical investigation of Boscia senegalensis (Per) Lam. ex Poir. led to the isolation of one new flavonol glycoside, rhamnocitrin-3-O-beta-D-(6 '' O-E-feruloyl)-glucopyranoside named bosenegaloside A (1), with seven known compounds, rhamnocitrin-3-O-beta-D-(6"-O-E-p-coumaroy1)-glucopyranoside (2), rhamnocitrin3-O-beta-D-glucopyranoside (3), 3,4,5-trimethoxyphenol-beta-D-glucopyrinoside (4), lasianthionoside A (5), 3,7dimethyl-l-octene-3,6,7-trio1-6-O-beta-D-glucopyranoside (6), syringin (7), and austroside B (8). The chemical structures of these compounds were elucidated from spectroscopic data and by comparison of these data with previously published results. The inhibitory activity of the isolated compounds on soluble epoxide hydrolase (sEH) was assessed. Compounds 1-3 potently inhibited sEH activity with IC50 values of 12.8 +/- 0.5, 18.4 +/- 0.2, and 11.3 +/- 0.9 mu M, respectively.