Reaction of 3-Dehydroshikimic Acid with Molecular Oxygen and Hydrogen Peroxide: Products, Mechanism, and Associated Antioxidant Activity
Reaction of 3-Dehydroshikimic Acid with Molecular Oxygen and Hydrogen Peroxide: Products, Mechanism, and Associated Antioxidant Activity
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DOI：
10.1021/ja952317i
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发表时间：
1996-11
影响因子：
15
通讯作者：
J. Richman;Y. C. Chang;S. Kambourakis;K. Draths;Erick A Almy;K. Snell;G. Strasburg;J. W. Frost
中科院分区：
文献类型：
--
作者：
J. Richman;Y. C. Chang;S. Kambourakis;K. Draths;Erick A Almy;K. Snell;G. Strasburg;J. W. Frost
在分子氧或过氧化氢存在下，无机磷酸盐催化3-脱氢莽草酸（DHS）转化为没食子酸。DHS与氧反应形成的其他产物包括原儿茶酸、丙三羧酸和焦性没食子酸。使用过氧化氢作为氧化剂，没有观察到焦性没食子酸的形成，并且产生较少量的丙三羧酸。证据有利于涉及磷酸盐催化的DHS的互变异构反应的反应性englutamine中间体的机制如下从二氢没食子酸的成功分离时，氧化剂被排除在磷酸盐缓冲溶液的DHS。DHS的还原酮样溶液化学和从DHS形成的酚类化合物的自由基淬灭反应性促使DHS的抗氧化活性的评估。基于两种不同的分析，发现DHS相对于α-生育酚、没食子酸、没食子酸丙酯和叔丁基对苯二酚具有显著的抗氧化活性。
In the presence of molecular oxygen or hydrogen peroxide, inorganic phosphate catalyzes the conversion of 3-dehydroshikimic acid (DHS) into gallic acid. Other products formed in the reaction of DHS with oxygen include protocatechuic acid, tricarballylic acid, and pyrogallol. With hydrogen peroxide as oxidant, pyrogallol formation is not observed, and smaller amounts of tricarballylic acid are produced. Evidence favoring a mechanism involving phosphate-catalyzed tautomerization of DHS to a reactive enediol intermediate follows from the successful isolation of dihydrogallic acid when oxidant is excluded from phosphate-buffered solutions of DHS. The reductone-like solution chemistry of DHS and the radical quenching reactivity of the phenolics formed from DHS prompted an appraisal of DHS antioxidant activity. Based on two different analyses, DHS was discovered to possess significant antioxidant activity relative to α-tocopherol, gallic acid, propyl gallate, and tert-butylhydroquinone.