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*) scavenging components from fruits of Capparis spinosa L. (Capparaeae). Ethyl acetate and aqueous fractions showed greater DPPH* 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.