【作者】 郭爽；

【导师】 杨国宇； 王艳玲；

【作者基本信息】 河南农业大学 ， 基础兽医学， 2005， 硕士

【摘要】 本试验采用两种方法DPPH法和FRAP法,选用我国允许并且广泛使用的四种合成抗氧化剂—TBHQ、BHT、BHA、PG,对其单一抗氧化活性以及两两组合的复合抗氧化剂的活性加以研究。另外,在国内首次提出了一种测定物质总抗氧化活性的新方法,并对该检测体系所需的反应条件作了初步探讨。 系列Ⅰ 用DPPH法研究了四种合成抗氧化剂—TBHQ、BHT、BHA、PG的单一抗氧化活性,结果表明,与对照组相比,四种抗氧化剂对DPPH自由基均有显著的清除作用（P<0.05）,并且随着抗氧化剂浓度的提高,各抗氧化剂对DPPH自由基的清除作用逐渐增强,且不同浓度组间对DPPH自由基的清除作用差异显著（P<0.05）。四种抗氧化剂TBHQ,BHT,BHA,PG的IC₅₀（清除率为50%时抗氧化剂浓度）分别为24.789umol/L,46.478umol/L,35.772umol/L,28.699umol/L。可知,对DPPH清除作用方面,四种抗氧化剂的活性为TBHQ>PG>BHA>BHT。 系列Ⅱ 用DPPH法对抗氧化剂两两组合—TBHQ+BHT,TBHQ+BHA,BHT+PG,BHT+BHA,PG+BHA,结果显示,当复合组中一种抗氧化剂的浓度一定时,复合抗氧化剂对DPPH自由基的清除效果,随着另一组分浓度的增大而增强,增大任一组分浓度皆有助于复合抗氧化剂活性的提高,说明组合中单一组分对复合抗氧化剂活性均有正影响,组分间具有抗氧化正协同作用。且复合抗氧化剂的抗氧化活性,受组分中浓度高的影响较大。 系列Ⅲ 采用FRAP法对四种常见的合成抗氧化剂的氧化活性加以研究,结果表明,各种抗氧化剂的FRAP值与其浓度均具有显著的相关性。当FRAP值为0.5mmol时,四种抗氧化剂TBHQ,BHT,BHA,PG的浓度分别为0.6119mmol/L,6.6756mmol/L,0.6239mmol/L,0.5895mmol/L,即BHT>BHA>TBHQ>PG。又因为达到同一FRAP值时,物质的浓度与其抗氧化活性成反比,所以四种抗氧化剂的总抗氧化能为:PG>TBHQ>BHA>BHT。 系列Ⅳ 首次采用FRAP法对四种常见的合成抗氧化剂TBHQ,BHT,BHA,PG的联合作用加以研究。四种酚类抗氧化剂组合时,试验所研究的五种组合TBHQ+BHT,TBHQ+BHA,BHT+PG,BHT+BHA,PG+BHA中,研究结果表明:在试验浓度范围内,复合抗氧化剂中一种组分的浓度确定时,复合抗氧化剂的总抗氧化活性均随组合中另一抗氧化剂浓度的增加而增强,说明单一组分均对复合抗氧化剂的活性有正影响;复合抗氧化剂总抗氧化活性均大于同浓度下单一组分的总抗氧化活性,但是又低于两种单一组分的活性之和,说明复合抗氧化剂的两种单一组分间存在正协同作用,但不是两种抗氧化剂作用的简单叠加。 系列Ⅴ 本试验,采用Trolox（VE的水溶性类似物）作为还原性物质,BC的类似物BCS作为cu^-的特定螯合剂,提出一种测定物质总抗氧化能新的间接分光光度法,对检测体系的试验条件作了初步探讨。结果表明,新方法的测定体系最佳吸收波长为480nm,体系中cu²⁺与BCS最适摩尔浓度比为1:2.5,cu²⁺与BCS的添加剂量均大于3ml时体系吸光度值稳定,最适pH环境为5.6,在试验条件下,反应时间达5min时体系已完全反应,此后至少在本试更多还原

【Abstract】 In this paper, we evaluated the individual and the combined antioxidant capacities of the typical composed-antioxidants-TBHQ BHT BHA PG. In addition, a new method to evaluate total antioxidant power of samples was posed firstly in domestic and the factor of this reaction system was investigated.In series I , the individual antioxidant activity of TBHQ BHT BHA PG was studied by DPPH assay. The results illustrated that: all of the four composed-antioxidant had significant activity of scavenging DPPH radical ;compared with the control group, different concentration of the every antioxidant had significant activity of scavenging DPPH radical in a dose-dependent manner(P < 0.05); The IC50 of TBHQ, BHT, BHA, PG were 24.789μmol/L, 46.478μmol/L,35.772μmnol/L, 28.699μmol/L separately; the results showed that the scavenging ability of DPPH radical from the highest to the lowest was TBHQ, PG, BHA, BHT.In series II, the antioxidant activities of the mixed antioxidants-TBHQ+BHT, TBHQ+BHA, BHT+PG, BHT+BHA, PG+BHA were studied by DPPH assay. The results illustrated that: for the five kind of mixed-antioxidant, the scavenging ability of DPPH radical of had raised with the concentration of any of their components ; every component had an positive effect on the antioxidant activity of the mixed-antioxidants , the higher-concentration component had more dominant effect on the antioxidant capacity of the mixed-antioxidant, the two component of the mixed-antioxidant had synergistic effects .In series III, the FRAP assay was used to measure the total antioxidant power of TBHQ, BHT, BHA, PG . The results showed that: The FRAP values of every antioxidant was related to the concentration of them; in the same FRAP values (0.5mmol), the concentration of TBHQ, BHT, BHA, PG were 0.6119mmol/L, 6.6756 mmol/L, 0.6239 mmol/L, 0.5859 mmol/L separately ;the order of the antioxidant capacity from the highest to the lower was PG,TBHQ,BHA,BHT.更多还原