Arnao M B, Cano A, Alcolea J F, Acosta M
Department of Plant Biology (Plant Physiology), University of Murcia, 30100-Murcia, Spain.
Phytochem Anal. 2001 Mar-Apr;12(2):138-43. doi: 10.1002/pca.571.
The chromogen 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS.+) can be directly generated by the enzymatic system formed by hydrogen peroxide and horseradish peroxidase in ethanolic media. The reaction is time- and concentration-dependent, and the ABTS.+ generated shows excellent stability. The method is an adaptation of the decolouration method previously reported (Cano et al. 1998. Phytochem Anal 9:196-202), which was used for estimating anti-oxidant activity in aqueous media. When the assay described here was used to quantify the anti-oxidant activity of two anti-oxidants, Trolox (an analogue of vitamin E) and beta-carotene, the latter had 2.5 times better anti-oxidant capacity than Trolox at the same concentration. The free radical quenching activity (anti-oxidant activity) of leaf pigment extracts was measured and related to the the carotenoid contents in leaf extracts of barley, oat and citrus. The possibilities of using this experimental approach to evaluate the status of photoprotective pigments are discussed.
色原2,2'-联氮-双-(3-乙基苯并噻唑啉-6-磺酸)自由基(ABTS.+)可由乙醇介质中的过氧化氢和辣根过氧化物酶形成的酶系统直接产生。该反应具有时间和浓度依赖性，生成的ABTS.+表现出优异的稳定性。该方法是对先前报道的脱色法（Cano等人，1998年。《植物化学分析》9:196 - 202）的改进，该方法用于评估水性介质中的抗氧化活性。当使用本文所述的测定方法来量化两种抗氧化剂Trolox（维生素E的类似物）和β-胡萝卜素的抗氧化活性时，在相同浓度下，后者的抗氧化能力是Trolox的2.5倍。测定了叶片色素提取物的自由基淬灭活性（抗氧化活性），并将其与大麦、燕麦和柑橘叶片提取物中的类胡萝卜素含量相关联。讨论了使用这种实验方法评估光保护色素状态的可能性。
