Arts Mariken J T J, Haenen Guido R M M, Voss Hans-Peter, Bast Aalt
Department of Pharmacology and Toxicology, Faculty of Medicine, Maastricht University, PO Box 616, 6200 MD, Maastricht, The Netherlands.
Food Chem Toxicol. 2004 Jan;42(1):45-9. doi: 10.1016/j.fct.2003.08.004.
The Trolox Equivalent Antioxidant Capacity (TEAC) assay is based on the scavenging of the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical (ABTS()) converting it into a colorless product. The degree of decolorization induced by a compound is related to that induced by trolox, giving the TEAC value. The assay is frequently used for constructing structure activity relationships (SARs). HPLC analysis of the reaction mixture, obtained after scavenging of ABTS() by the flavonoid chrysin, shows that a product is formed that also reacts with ABTS(). The product has a higher antioxidant capacity and reacts faster with ABTS() than the parent compound, chrysin. In contrast to the reaction product of chrysin, the reaction product of trolox, which is formed during scavenging of ABTS(), i.e. trolox quinone, does not react with ABTS(). The experiments show that the TEAC is the antioxidant capacity of the parent compound plus the potential antioxidant capacity of the reaction product(s). This means that the TEAC assay does not necessarily reflect the antioxidant effect of only one structure. This hampers the applicability of the assay for the construction of SARs and for ranking antioxidants.
特洛克斯等效抗氧化能力（TEAC）测定法基于对2,2'-联氮双（3-乙基苯并噻唑啉-6-磺酸）（ABTS）自由基（ABTS(+)）的清除，将其转化为无色产物。化合物引起的脱色程度与特洛克斯引起的脱色程度相关，从而得出TEAC值。该测定法常用于构建构效关系（SARs）。对黄酮类化合物白杨素清除ABTS(+)后得到的反应混合物进行高效液相色谱（HPLC）分析表明，形成了一种也能与ABTS(+)反应的产物。该产物具有更高的抗氧化能力，并且与ABTS(+)反应的速度比母体化合物白杨素更快。与白杨素的反应产物不同，在清除ABTS(+)过程中形成的特洛克斯的反应产物，即特洛克斯醌，不与ABTS(+)反应。实验表明，TEAC是母体化合物的抗氧化能力加上反应产物的潜在抗氧化能力。这意味着TEAC测定法不一定仅反映一种结构的抗氧化效果。这妨碍了该测定法在构建SARs和对抗氧化剂进行排名方面的适用性。
