黄酮配合物抗自由基活性的亚甲基蓝光谱测定体系的研究

亚甲基蓝(MB)可捕获Fenton反应产生的羟自由基生成无色加合物,选用亚甲基蓝为槲皮素(Que)及其配合物抗羟自由基活性测定体系的指示剂.实验优化测试条件为:体系pH 8.0,加入H2O2溶液(0.3%)0.50 mL,FeSO4溶液(5 mmol·L-1)0.50 mL和MB溶液(2.56×10-5 mol·L-1)1.0 mL.由此建立了测定槲皮素配合物抗·OH活性的光谱测定方法.方法简便,尤其适合于配合物体系抗自由基活性的分析.测定了槲皮素及Que-Zn(Ⅱ),Que-Cu(Ⅱ),Que-Fe(Ⅲ)配合物的抗·OH活性.结果表明3种槲皮素配合物的抗羟自由基活性均比槲皮素高,配合物活性Que-Cu(Ⅱ)＞Que-Zn(Ⅱ)＞Que-Fe(Ⅲ),表现出金属离子与有机活性配体协同作用可提高其抗氧化活性的能力.

Study on Fenton-Methylene Blue Spectral Analysis Method for Determining the Inhibitory Effect of Quercetin Complexes on Hydroxyl Free Radical

In the present, Fenton-Methylene Blue spectral measurement was established, and the new analytical method was applied successfully to determine the inhibitory effect of quercetin (Que) and its complexes on hydroxyl free radical. Methylene Blue(MB) can capture the *OH produced by Fenton reaction, turning its color from blue to achromatic. Therefore, MB was selected as the indicator of the spectral measure study. The testing conditions optimized were pH 8. 0, H2O2 solution (0. 3%) 0. 50 mL, FeSO4 solution (5 mmol x L-1) 0. 50 mL and MB solution(2. 56 x 10(-5) mol x L(-1) )1.0 mL. The experiment results showed that Que-Zn( II), Que-Cu( II) and Que-Fe( III) complexes held significant effects of scavenging action on *OH radical and were more effective in scavenging *OH than quercetin itself, showing the good cooperative action between quercetin and trace metal elements. The structure-bioactivity relationship of the coordination complexes was also discussed through analyzing the antioxygenic activity of quercetin-metal complexes.