A new antioxidant compound from Capparis spinosa

An activity-directed fractionation and purification process was used to isolate 1,1-diphenyl-2-picrylhydrazyl radical (DPPH center dot) scavenging components from fruits of Capparis spinosa L. (Capparaeae). Ethyl acetate and aqueous fractions showed greater DPPH center dot scavenging activities compared to the petroleum ether fractions. The ethyl acetate fraction was subjected to purification using column chromatography. A new antioxidant cappariside (4-hydroxy-5-methylfuran-3-carboxylic acid, 1), together with seven known organic acids (2-8) for the first time from plants of genus Capparis and four known organic acids (9-12) were isolated from C. spinosa. The structures were elucidated by extensive analysis of 1D- and 2D-NMR spectroscopic. In addition, compounds 1, 2, 4, 5, 9, 10 and 12 indicated strong scavenging capacity for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals with a SC(50) value of 0.204 +/- 0.002, 0.007 +/- 0.0, 0.011 +/- 0.0, 0.044 +/- 0.0016, 0.032 +/- 0.0, 0.090 +/- 0.001, and 0.350 +/- 0.017 mM, respectively.