采用电子自旋共振法(ESR)对葛根黄酮4个提取样(CEP1,CEP2,CEP3,CEP4)抗氧化性能进行研究,同时采用可见分光光度法进行对比实验。将4份样品与1,1-二苯基-2-三硝基苯肼(DPPH)溶液混合,分别置于电子顺磁共振波谱仪与可见分光光度计中检测。结果表明:在ESR测定法里,不同的反应时间,同一份样品对DPPH·的清除率和质量浓度成正比例关系,在质量浓度为60 mg/L时,自由基的清除率有显著的提高。ESR处理时间30 min,60%乙醇洗脱液葛根冻干粉自由基清除率可以达到100%。ESR法能更灵敏、更准确地测定自由基清除效果。

Electron spin resonance( ESR) was used to study the antioxidant properties of flavonoids in four Pueraria extract samples( CEP1,CEP2,CEP3,CEP4) and Visible spectrophotometry was also used as comparison. Four samples mixed with DPPH solution were placed in electron paramagnetic resonance spectrometer and detected by Visible spectrophotometer. In the ESR assay,the different reaction time,with a clearance rate and quality of sample concentration on DPPH radical proportional relationship in the concentration of 60 mg /L,the free radical scavenging rates were significantly improved. ESR treatment time was 30 min,radical scavenging rate of Pueraria lyophilized powder eluated by 60% ethanol can reach to 100%. ESR method is more sensitive and more accurate in the determination of free radical scavenging effect. This study provides a scientific basis for the extraction and research of antioxidants.