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Antioxidant Mechanism Studies for Food Phenol Based on the Radical Reaction Products with Food Components

基于食品成分自由基反应产物的食品苯酚抗氧化机理研究

基本信息

批准号：
12660116
负责人：
MASUDA Toshiya
金额：
$ 2.18万
依托单位：
The University of Tokushima
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

The antioxidation process of the chain-breaking antioxidant is divided into the following two stages : 1) Radical Trapping Stage (S-OO + AH →← SOOH + A) 2) Radical Termination Stage (A → non-radical materials) The second is irreversible and must produce stable radical termination compounds. The chemical structure of such a termination compound would afford important information in order to elucidate the antioxidant mechanism of the chain breaking antioxidant. Curcumin is a famous antioxidatively active food phenol from turmeric. By this research for the antioxidant mechanism based on the chemical structures of the radical termination products, curcumin is revealed to react with a peroxyl radical to afford stable 3-ringed compounds. When curcumin is in a higher concentration, it affords dimers as terminated compounds. Carnosic acid is an abietane diterpene found in the popular Labiatae herbs, sage and rosemary. Carnosic acid has the most powerful antioxidant potency among related diterpenes. The 11-phenolic group of carnosic acid first undergoes hydrogen donation to a radical species and the radical termination takes place next with a second lipid peroxyl radical at the ortho and parapositions. When the coupling proceeds at the 12-position (ortho-position), it affords a carnosic quinone through several steps. When the coupling proceeds at the 14-position (para-position), it affords a hydroxylparaquinone derivative. Generally, antioxidant loses the activity after its work. The orthoquinone derivative of carnosic acid has no antioxidant activity ; however, we found that its solution became to show potent antioxidant activity. The recovery mechanism of the antioxidant activity from the quinone was clarified to be by a self-redox reaction of the quinone, therefore, procuded carnosic acid contributes the strong antioxidant activity of the quinone solution.

断链抗氧剂的抗氧化过程分为以下两个阶段：1）自由基捕获阶段（S-OO + AH →← SOOH + A）2）自由基终止阶段（A →非自由基物质）第二个是不可逆的，必须产生稳定的自由基终止化合物。这种封端化合物的化学结构将为阐明断链抗氧化剂的抗氧化机理提供重要信息。姜黄素是从姜黄中提取的一种具有抗氧化活性的食品酚。通过对自由基终止产物的化学结构的研究，发现姜黄素可以与过氧自由基反应生成稳定的三环化合物。当姜黄素处于较高浓度时，其提供作为封端化合物的二聚体。鼠尾草酸是一种松香烷二萜，存在于流行的唇形科草药、鼠尾草和迷迭香中。鼠尾草酸在相关的二萜中具有最强的抗氧化能力。鼠尾草酸的11-酚基首先经历氢捐赠的自由基物种和自由基终止发生接下来与第二个脂质过氧自由基在邻位和对位。当在12位（邻位）进行偶联时，通过几个步骤得到鼠尾草醌。当在14位（对位）进行偶联时，得到羟基对醌衍生物。一般来说，抗氧化剂在起作用后会失去活性。鼠尾草酸的邻醌衍生物不具有抗氧化活性;然而，我们发现其溶液变得显示出有效的抗氧化活性。从醌的抗氧化活性的恢复机制被澄清是通过醌的自氧化还原反应，因此，产生鼠尾草酸有助于醌溶液的强抗氧化活性。