State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China; Guangdong Engineering Research Center for Green Fine Chemicals, South China University of Technology, Guangzhou 510640, China.
Food Chem. 2018 Dec 15;269:480-485. doi: 10.1016/j.foodchem.2018.07.038. Epub 2018 Jul 5.
In this study, 11 dehydrodiferulic acids (DFAs) and 8 diethyl dehydrodiferulates (DEFs) were synthesized and evaluated by Trolox equivalent antioxidant capacity (TEAC) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assays for their antioxidant properties to understand the Structure-Antioxidant Activity Relationship (SAR) of these dehydrodiferulates. In both assays, the order of antioxidant activity for all tested ferulic acid dimers were consistent except for 3-(4-Hydroxy-3-methoxy-benzylidene)-5-(4-hydroxy-3-methoxy-phenyl)-3H-furan-2-one (2, 8-8-lactone DC DFA, not occurred naturally) being the best antioxidant by TEAC test. The order of antioxidant activity of diferulic acid ethyl esters, evaluated by both assays, was not consistent; however, TEAC and DPPH assays provided consistent results for certain set of ethyl diferulates. In this study most of dimeric ferulates, with three exceptions, showed higher radical-scavenging efficacy than the monomers. Comparing the antioxidant activities of the tested diferulates suggested that the phenolic hydroxyl group, electron donating methoxyl group, and stable conjugated transient structures dictate the antioxidant activity of diferulates.
在这项研究中，合成了 11 种去氢二阿魏酸（DFA）和 8 种二乙基去氢二阿魏酸（DEF），并通过 Trolox 当量抗氧化能力（TEAC）和 2,2'-二苯基-1-苦基肼（DPPH）测定法评估了它们的抗氧化性能，以了解这些去氢二阿魏酸的结构-抗氧化活性关系（SAR）。在这两种测定方法中，除了 3-(4-羟基-3-甲氧基-苄叉基）-5-(4-羟基-3-甲氧基-苯基）-3H-呋喃-2-酮（2，8-8-内酯 DC DFA，未自然发生）之外，所有测试的阿魏酸二聚体的抗氧化活性顺序都是一致的，2 通过 TEAC 测试是最好的抗氧化剂。通过这两种测定方法评估的阿魏酸乙酯的抗氧化活性顺序不一致；然而，TEAC 和 DPPH 测定法为某些特定的乙酯二聚体提供了一致的结果。在这项研究中，大多数二聚体阿魏酸（除了三个例外）比单体具有更高的自由基清除功效。比较测试的二聚体的抗氧化活性表明，酚羟基、供电子甲氧基和稳定的共轭瞬态结构决定了二聚体的抗氧化活性。
