水溶性抗氧化剂清除羟自由基能力的ESR评价方法

Estimating the Effects of Water-soluble Antioxidant on Eliminating Hydroxyl Radicals by ESR and Spin Trapping Technique

目的 建立评价水溶性抗氧化剂清除羟自由基能力的ESR方法。方法 通过加入水溶性的抗氧化剂 ,减弱DMPO自旋捕获Fenton反应产生的羟自由基的加合物 (DMPO -OH·)信号强度 ,信号强度减弱的程度反映抗氧化剂清除羟自由基的能力。结果 ⑴信号指标采用DMPO -OH·加合物ESR谱第 2峰的相对峰高 ;⑵当 [Fe2 + ]为0 .749mmol·l-1、[H2 O2 ]>6 .49mmol·l-1、DMPO取 5 μl、间隔时间严格控制在 6 0s,方法可用于评价 ;⑶抗氧化剂清除羟自由基的能力可通过IC50 来反映。结论 用ESR测量DMPO捕获Fenton反应产生的羟自由基的方法可用于评价水溶性抗氧化剂清除羟自由基的能力。

Purpose To establish a method for estimating the effects of antioxidants on eliminating hydroxyl radicals by ESR. Method Hydroxyl radicals produced in Fenton reaction is determinated by ESR with spin trapping technique, and the effects of antioxidants on eliminating hydroxyl radicals were related with the decrease of relative peak height of ESR spectra of DMPO-OH·adducts. Results ⑴The relative peak height of second peak in ESR spectra of DMPO-OH·adducts was regarded as signal intensity. ⑵The method was effective under some conditions. ⑶Effects of antioxidants on eliminating hydroxyl radicals was able to be expressed with IC 50 . Conclusion It is effective to estimate the effects of antioxidants on eliminating hydroxyl radicals by ESR with DMPO trapping Hydroxyl radicals produced in Fenton reaction.