3种大黄素金属配合物的抗氧化活性研究

目的:对比配体大黄素和其3种金属配合物的体外抗氧化活性.方法:以天然大黄素和相应的金属盐为原料,在无水乙醇中合成了大黄素-锌、大黄素-锰、大黄素-铁(Ⅲ)等3种配合物,并对其结构进行表征.采用紫外可见分光光度法,分别考察了配体和配合物对二苯代苦味肼基自由基(DPPH)、超氧自由基(O2-·)、羟基自由基(·OH)等3种自由基的清除率.结果:配体及配合物对3种自由基均有一定清除作用.其中大黄素-铁(Ⅲ)清除羟基自由基活性最强,其半数有效浓度(EC50)值达19.96 mg·L-1小于大黄素(EC50147.87 mg·L-1)、大黄素-锌(EC50 30.76 mg·L-1)、大黄素-锰(EC50 100.04 mg·L-1)；大黄素-铁(Ⅲ)清除超氧自由基活性也为最强,其EC50达60.832 mg·L-1,小于大黄素(EC50853.152 mg·L-1)、大黄素-锌(EC50436.296mg·L-1)、大黄素锰(EC50 161.949 mg·L-1)；实验范围内(1×10-4mmol·L-1≤C≤4×10-3 mmol·L-1)配合物和配体对DPPH自由基清除活性总体不强,均小于25％,但配合物活性稍高于配体.结论:大黄素与Fe3+,Zn2+,Mn2+离子形成配合物后抗氧化活性增强,其中以大黄素-铁(Ⅲ)配合物抗氧化活性最高.

Concentration for 50% of Maximum Effect Study of Antioxidant Activity of 3 Emodin Metal Complex

Objective: To compare the antioxidant activity of emodin and 3 emodin metal complex. Method: Compound the 3 emodin metal complex,then use the UV spectrum,study the clearance rate of emodin and 3 emodin metal complex to DPPH free redical,O₂^-·free redicals and ·OH free redical. Result: For·OH free redical, the Concentration for 50% of Maximum Effect(EC₅₀) of emodin-ferrum reaches 19.96 mg·L^-1,this numerical value is the smallest one of all,So emodin-Ferrum the best one.For the same reason, the antioxidant activity for O₂^-·free redicals of emodin-Ferrum is the best. Conclusion: The antioxidant activity enhance after forming metal complex,and emodin-Ferrum is the best one.