Chungnam National University, South Korea
Title: Chemical constituents of the leaves of Boscia senegalensis
Biography: Abubaker M A Morgan
The genus Boscia (Capparaceae) contains more than 37 species distributed mainly in Africa, excluding one species found in southern Arabia. Boscia senegalensis (Pers.) Lam. ex. Poir. is an evergreen shrub reaching 7 meters in height. It is native to the Sahel and Sahara savannas stretching from Mauritania, Senegal, Mali, Niger and Nigeria to Cameroon and across Africa to Egypt, Sudan, Ethiopia, Somalia and Kenya. The importance of B. senegalensis for the rural agro-economy in Africa has been discussed in several reports, making it a plant of high value for both humans and animals. Previous phytochemical reports on B. senegalensis, which were conducted on the leaves and fruits, identified glucosinolate. Detailed chemical investigation of Boscia senegalensis (Per) Lam. ex Poir led to the isolation of one new flavonol glycoside, rhamnocitrin-3-O-β-D-(6''-O-E-feruloyl)-glucopyranoside named bosenegaloside A (1), with seven known compounds, rhamnocitrin- 3-O- β-D- (6''-O-E-p-coumaroyl)- glucopyranoside (2), rhamnocitrin- 3-O-β-D-glucopyranoside (3), 3,4,5-trimethoxyphenol-β-D-glucopyrinoside (4), lasianthionoside A (5), 3,7-dimethyl-1-octene-3,6,7-triol-6-O-β-D-glucopyranoside (6), syringin (7), and austroside B (8). The chemical structures of these compounds were elucidated from spectroscopic data (ESI-MS, HR-ESI-MS, 1D, 2D-NMR, UV and FT-IR) and by compared 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 µM, respectively.