Adenine and cytosine: Basic polarographic behavior and its interpretation

Abstract

The basic information concerning the behavior on electrochemical reduction in aqueous media at mercury electrodes of cytosine, adenine, model compounds, their nucleosides and nucleotides, and their simpler polymers, is summarized and interpreted with particular reference to the effects of the addition of sugar and sugar--phosphate substituents on the course of the faradaic redox process, intermediate chemical steps in that process, the kinetics and energetics of individual steps, association in solution, and adsorption at the solution|electrode interface and association in the adsorbed state. Since cytosine and adenine are the only two nucleic acid bases, which are normally electrochemically reducible in aqueous media, it is hoped that the discussion will provide the background necessary for the interpretation of the observed behavior on electrochemical reduction (e.g., at dropping and hanging drop mercury electrodes) of polymeric species as in the polarographic studies of DNA and RNA, and synthetic polynucleotides.