Extracting technology and antioxidant activity of bio-active components from the old leaves of Toona sinensis

The technology for extracting the antioxidants from the old leaves of Toona sinensis was studied, the most suitable macroporous resin for purifying the antioxidants was selected and the antioxidant activities were studied. The results show that the optimal parameters of the extracting technology are that the concentration of ethanol is 60%, the extracting temperature is 60℃, the ratio of sample to extracting solution is 1∶30 and the extracting time is 4 h. AB-8 macroporous resin is the optimal purifying resin. The antioxidants purified by the resin of AB-8 from Toona sinensis have strong antioxidative capacity. The reducing power of those purified antioxidants is (863.59±13.90)mg/g. The 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging capacity and Ferric Reducing Ability of Plasma(FRAP) values of antioxidants from Toona sinensis show dose-dependent fashion, are significantly higher than those of butylated hydroxytoluene(BHT) with the same concentrations(P<0.01) and almost have the same values as ascorbic acid.