Quantitative Analysis And Evaluation Of The Antioxidant Capacity Of Natural Compounds Bascd On The Macrocyclic Nikel Complex Catalyzed Briggs-Rauscher Oscillating System

Chemical oscillating reaction is a classical non-equilibrium nonlinear of chemical kinetics phenomenon. Some quantity of state in the oscillating system changes with the time and the spatial, periodically, under nonequilibrium circumstance. Scientists are focusing on exploring the reaction mechanism of chemical oscillating, and trying to put oscillating reaction into assay determination. A study to evaluate the antioxidant capacity based on the inhibitory effects on a macrocyclic Ni(Ⅱ) complex-catalyzed Briggs-Rauscher reaction was reported in this paper. The macrocyclic Ni(Ⅱ) complex, NiL(ClO4)2, where L is5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene is a porphyrin-link compounds.1. A study to evaluate the inoxidizability of antioxidant based on the nonlinear Briggs-Rauscher oscillating reactionWe attempt to evaluate three polyphenolic natural antioxidant’s (Rutin, protocatechuic acid and proanthocyanidins) inoxidizability based on the inhibitory effects on the Briggs-Rauscher oscillating reaction. Firstly, we established a steady nonlinear chemical oscillating system--"H++[NiL](ClO4)2+IO3-+CH2(COOH)2+H2O2".We adopted the proportion of every substance get from above experiments for the better testing results. The experiments indicated the relationship between the three polyphenolic natural antioxidant and inhibiting time is linear. We sum up the linear relationship between each antioxidants and corresponding inhibiting time under the same circumstance. We evaluated their antioxidant capacity by contrasting the slope of each natural antioxidant’s linear graphs. The experiment results show that of the three natural compounds proanthocyanidins was found to be more efficient antioxidant. We discussed the reaction of antioxidant with hydroperoxyl radical (HOO) presented in the B-R oscillating system.2. Perturbations of the nonlinear Briggs-Rauscher oscillating reaction by rutin.In this section, we explored the perturbation effects of the polyphenolic rutin on the of B-R oscillating system, In order to detect the influence of every compound in the B-R oscillating system to the determine rutin, we prepared a series of experiments with different concentration of every substance. The catalyst [NiL](ClO4)2was prepared according to a published procedure frist. Then, we discussed the relationship between inhibiting time and every substance in oscillating system.By changing the concentration of every substance in the nonlinear chemical oscillating reaction--"H++[NiL](ClO4)2+IO3-+CH2(COOH)2+H2O2", we prepared a series of comparative experiments.When the perturbation of oscillating system by rutin is sensitive with stable oscillating and wide detecting range, we got the best proportion of every species.3. Quantitive analysis of natural antioxidant using the Ni(II)complex-catalyzed B-R oscillating system.Firstly, we established a steady nonlinear chemical oscillating system--"H++[NiL](ClO4)2+IO3-+CH2(COOH)2+H2O2". In order to probing into the perturbation effects caused by two different kinds of natural antioxidant (ascorbic acid, phytic acid) with different structure on the stable B-R chemical oscillating reaction, we designed a series of experiments. The experiment result indicated that a certain amount of ascorbic acid (1×10-5mol/L-6×10-4mol/L) caused sharply increasing in amplitude and the relationship between concentration and extends range of oscillating amplitude is linear. A certain amount of phytic acid (2×10-4mol/L-2×10-3mol/L) could cause increasing in period and the concentration and extends range of oscillating period is linear. We obtain two conclusions through above a series of experiments. One is the perturbation of the B-R oscillation system varies from antioxidant to another with different structure. The other one is the relationship between concentration of antioxidants and inhibiting time is linear.