山奈酚-铜配合物的合成、表征及其抗氧化活性的研究

摘要

以山奈酚和二水合氯化铜为原料,合成山奈酚-铜金属配合物,通过紫外光谱、红外光谱、核磁共振氢谱及差热-热重分析对其结构进行表征,并采用DPPH法测定了配合物清除自由基的能力.结果表明:相比山奈酚,配合物的紫外光谱和红外光谱的吸收峰均发生明显红移;核磁共振氢谱中3-OH信号消失,其他质子信号均向高场移动;差热-热重分析显示山奈酚和Cu2的配位比为1,且配合物中含三分子的配位水;在6种设定的实验浓度内(1.0～3.5 mol/L),山奈酚和配合物清除DPPH·半抑制浓度(IC5o)分别为1.63×10-4、1.51×10-4 mol/L.Cu2是通过与山奈酚3位羟基和4位羰基的氧原子结合生成配合物,山奈酚与铜形成配合物后,对DPPH自由基的清除率有提高.%Kaempferol-copper (Ⅱ) complex (kaempferol-Cu) was synthesized with kaempferol and CuCl2 · 2H2 O,and its chemical properties were characterized by UV spectroscopy,infrared spectroscopy,1H-NMR and differential thermal analysis.The free radical activity of the complex was evaluated by DPPH method.The result showed that the UV-visible,Infra -red absorption spectra of the complex both produced a significant bathochromic shift.The 1H NMR data shows the 3-OH groups was not presented in the complex,and the proton signals of the complex shifted to lower frequencies relative to that of the free kaempferol.The differential thermal-thermal analysis confirming that the stoichiometric ratio for the complexation of Cu (Ⅱ) and kaempferol was 1:1,and the complex contains three coordinated water molecules.In the range of experimental concentration(1.0～3.5 mol/L),the IC50 of DPPH free radical of the kaempferol and complex was 1.63 × 10-4,1.51 ×10-4 mol/L respectively.The synthesized complex was coordinated with a Cu (Ⅱ) ion via the 3-OH and 4-oxo groups,kaempferol-Cu exhibited more potent antioxidant effect than kaempferol.