生物小分子的电化学分析研究 Ⅲ.维生素B_2电化学还原反应的表征

Study on Electroanalytical Chemistry of Small Biological Molecules Ⅲ. Characterization of Electrochemical Reduction of Vitamin B_2

用电化学、光谱电化学和顺磁共振谱等方法对维生素B_2在粗热解石墨电极上的电化学还原机理进行了表征。结果表明维生素B_2在粗热解石墨电极上的还原为2e、2H^+过程,它先经1e、1H^+过程还原生成自由电子定域在N(5)上的自由基中间体,然后再经1e,1H^+过程还原为二氢核黄素。

The electroreduction of vitamin B2(VB2) on rough pyrolytic graphite electrode (RPGE) was characterized by cyclic voltammetry, spectroelectrochemistry and electron spin resonance spectroscopy. The experimental results expressed that the reduction of VB2 was 2e/2H+ process on RPGE. The mechanism of electroreduction of VB2 was discussed . It is clear that the reduction of the first step was le/1H+ process to a riboflavin radical intermediate in which the free electron is fixed on N(5) position and followed via another le/ 1H+ reduction to dihydroflavin.