Comparing the Relative Reactivities of Food and Vitamin Molecules Toward Electrochemically Generated Superoxide in Dimethylformamide

Superoxide (O₂ ^.−), an anionic radical of the reactive oxygen species (ROS) family, is continuously produced in the body and can lead to the undesirable modification and damage of important biological molecules. In the present study, the relative reactivities of 18 food and vitamin molecules toward electrochemically generated O₂ ^.− were investigated in N,N-dimethylformamide (DMF) solutions by using cyclic voltammetry (CV). The quenching of O₂ ^.− was measured by monitoring the decreases in the anodic currents of the reverse peaks after the one-electron reduction of molecular oxygen (O₂), while systematically increasing the concentration of the test substrates. The reactivity of each compound was then approximated and compared using effective concentration indexes, EC₁₀ and EC₅₀, which represent the amount of compound required to reduce the concentration of the electrochemically generated O₂ ^.− by 10 and 50%, respectively, under the present conditions. Where possible, the likely mechanisms that are involved in the scavenging of O₂ ^.− are also discussed.