Study of electrochemical behavior of ergosterol by in situ thin layer circular dichroic spectroelectrochemistry

The electroxidation of ergosterol was studied by in situ circular dichroic (CD) spectroelectrochemistry with a long optical path length thin layer cel l. It was confirmed that the oxidation of ergosterol in ethanol solution is a two-electron irreversible electrochemical process with strong adsorption of an electroinactive product at the glassy carbon electrode, which blocks the electrochemical reaction. The CD spectroelectrochemical data were trea ted by the double logarithm method together with nonlinear regression, from which the formal potential, E-0 = 1.00 V, alpha n(alpha) = 0.302, the stan dard electrochemical rate constant, k(0) = 6.1(+/-0.4) x 10(-4) cm s(-1) an d the adsorption constant, beta = 19 +/- 1, were obtained. The number of el ectrons transferred (n = 1.86) was estimated by cyclic voltammetry.