Abstract:

The fructose in organisms can occur autoxidation reaction to produce kinds of free radicals, which transform to hydroxyl radical(·OH) finally. While ·OH can be captured by sodium benzoate to yield salicylate, which has strong fluroscence emission. The effects of fructose autoxidation were investigated and optimized using fluorescence method. A total of 19.27 μmol/L ·OH were produced under the conditions of pH=7.4, 37℃, reaction time 24 h and the concentrations of fructose, CuSO₄ and sodium benzoate of 8.00 mmol/L, 20.0 μmol/L and 24.0 mmol/L, respectively. Antioxidants can scavenge free radicals produced by fructose autoxidation, which resulted in less ·OH product. From these process and principle, a novel screening method for antioxidants were developed based on fructrose autoxidation system. The antioxidative capacity of berberine hydrochloride and ferulic acid were estimated using developed method. The antioxidative capacity of berberine hydrochloride is stronger than that of ferulic acid, their IC₅₀ values are 0.023 and 0.036 mmol/L, respectively.

Key words: Fructose, Autoxidation, Free radical, Antioxidant