Electrochemical Oxidation Of Selenium Amino Acids And Interaction Between Selenium Amino Acids And Au(Ⅲ)/Cu(Ⅱ)

The process of the biochemical transform of selenium amino acids is complicated, and its biological activation and physiological function are based on the electron transmition of selenium amino acid mainly. The electrochemical oxidation of selenocystine(SeC) and selenomethionine(SeMet), and the interaction between selenoamino acids and Au(â…¢), Cu(â…¡) are investigated. It can not only help to understand the redox of selenoamino acids and electron transfer process of selenoamino acids, but also supply significant information of structure and function in organism.Electrochemical oxidation of SeC and SeMet on a gold electrode was studied by voltammetry (CV and LSV), rotating disk electrode technique (RDE) chronocoulometry (CC) and tafle experiment. One anodic peak was observed at 800mV and 638mV for SeC and SeMet respectively, and this process was diffused controlled. The effects of pH value and continuum scanning on oxidative process I were studied. The electrochemical oxidation process of SeC, which was six-electron reaction, yielded organic selenous acid, and the following chemical reaction yielded an organic selenious acid anhydride. The electrochemical oxidation process of SeMet, which was two-electron reaction, yielded selenoxide.The electrochemical behavior of selenoamino acids and Au (â…¢) was studied with glass carbon electrode, which compared with the electrochemical behavior of other amino acid and Au (â…¢). The selenium amino acids and sulf-amino acids can react with Au(â…¢), Au(â…¢) was deoxidized to Au(0), and the reaction ability with Au(â…¢) of selenium amino acids were stronger than that of sulf-amino acids. It was proposed that SeMet yielded selenoxide and SeC yielded organic selenous acid.Based on the study of the ultraviolet-spectral property of Cu(â…¡), selenoamino acids and their complexes, the effect of pH on the system and the composition of these complexes were discussed. And the composition of Cu(â…¡) and selenoamino was 1:2, and stability constant (logβ₂) of Cu(â…¡)-SeC and Cu(â…¡)-SeMet were 16.69 and16.05 respectively. The electrochemical behavior of SeC and Cu(II) solution and the electrochemical process were studied. Two redox peaks were observed at 100mV/-90 mV (I'/IV) and 249mV/-233mV (II/V) for SeC and Cu(II) solution, and these processes were diffused controlled. Electrochemical process of I'/IV and II/V proposed are as following:Cu( II) ^F*Cu( I); Cu( II )-SeC ^Cu( I )-SeC.