Electrochemical degradation of quercetin: Isolation and structural elucidation of the degradation products
Electrochemical degradation of quercetin: Isolation and structural elucidation of the degradation products
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DOI：
10.1016/j.elecom.2007.06.026
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发表时间：
2007-09-01
影响因子：
5.4
通讯作者：
Sadik, Omowunmi A.
中科院分区：
文献类型：
--
作者：
Zhou, Ailing;Kikandi, Samuel;Sadik, Omowunmi A.
本文首次报道了槲皮素电化学氧化后18个中间体的完全分离、表征和结构鉴定，并提出了反应机理。在乙醇-PBS中性缓冲溶液(1：1，v/v，pH 7.40)中，采用本体电解法诱导槲皮素的氧化。同时进行的UV-Vis、循环伏安和差示脉冲伏安研究表明，槲皮素的诱导电化学氧化生成了新的产物。采用柱色谱、GC-MS和LC-MS-MS分析相结合的方法，实现了氧化产物的制备分离和验证。提出了一种可能的降解机理，包括形成半醌、邻苯二酚和甲基醌的电化学步骤，以及与紫杉酯、多酚、小酚酸、栎素乙醇加合物、苯并呋喃酮和二聚体形成复合降解产物的化学步骤。(C)2007 Elsevier B.V.保留所有权利。
This paper reports the first complete isolation, characterization and structural elucidation of 18 intermediates following the electrochemical oxidation of quercetin and provides a mechanism of reaction. Bulk electrolysis was employed to induce the oxidation of quercetin in ethanol-PBS buffered neutral solution (1:1, v/v, pH 7.40). Simultaneous UV-Vis, cyclic and differential pulse voltammetric studies indicated the formation of new products due to the induced electrochemical oxidation of quercetin. Preparative separation and the verification of the oxidized products were achieved using a combination of column chromatography, GC-MS and LC-MS-MS analyses. A possible mechanism for the degradation pathways of quercetin was proposed including an electrochemical step leading to the formation of semi-quinone, ortho-quinone and quinone methide, as well as a chemical step corresponding to the formation of complex degradation products of taxifolin, depside, small phenolic acids, quercetin-ethanol adduct, benzofuronone and dimer. (c) 2007 Elsevier B.V. All rights reserved.