Department of Physical Chemistry, Faculty of Chemistry, Rzeszów University of Technology, 35-959 Rzeszów, Poland.
Molecules. 2023 Nov 16;28(22):7618. doi: 10.3390/molecules28227618.
This review presents a description of the available data from the literature on the electrochemical properties of flavonoids. The emphasis has been placed on the mechanism of oxidation processes and an attempt was made to find a general relation between the observed reaction paths and the structure of flavonoids. Regardless of the solvent used, three potential regions related to flavonoid structures are characteristic of the occurrence of their electrochemical oxidation. The potential values depend on the solvent used. In the less positive potential region, flavonoids, which have an dihydroxy moiety, are reversibly oxidized to corresponding -quinones. The -quinones, if they possess a C3 hydroxyl group, react with water to form a benzofuranone derivative (). In the second potential region, () is irreversibly oxidized. In this potential region, some flavonoids without an dihydroxy moiety can also be oxidized to the corresponding -quinone methides. The oxidation of the hydroxyl groups located in ring A, which are not in the position, occurs in the third potential region at the most positive values. Some discrepancies in the reported reaction mechanisms have been indicated, and this is a good starting point for further investigations.
本综述介绍了文献中关于类黄酮电化学性质的可用数据。重点介绍了氧化过程的机制,并试图找到观察到的反应途径与类黄酮结构之间的一般关系。无论使用何种溶剂,与类黄酮结构相关的三个潜在区域都是其电化学氧化发生的特征。电位值取决于所用的溶剂。在较正的电位区域中,具有二羟基部分的类黄酮可被可逆地氧化为相应的-醌。如果-醌具有 C3 羟基,则与水反应形成苯并呋喃酮衍生物()。在第二个电位区域中,()不可逆地被氧化。在这个电位区域中,一些没有二羟基部分的类黄酮也可以被氧化为相应的-醌亚甲醚。位于 A 环中不在 位置的羟基的氧化在最正的电位值下发生在第三个电位区域。已经指出了报道的反应机制中的一些差异,这是进一步研究的良好起点。