ChemInform Abstract: One-Electron-Reduction Potentials of Pyrimidine Bases, Nucleosides, and Nucleotides in Aqueous Solution. Consequences for DNA Redox Chemistry.

Abstract

The reduction potentials in aqueous solution of the pyrimidine bases, nucleosides, and nucleotides of uracil (U) and thymine (T) were determined using the technique of pulse radiolysis with time-resolved spectrophotometric detection. The electron adducts of U and T were found to undergo reversible electron exchange with a series of ring-substituted N-methylpyridinium cations with known reduction potential. From the concentrations of the pyrimidine electron adducts and the reduced N-methylpyridinium compounds at electron-transfer equilibrium, the thermodynamical equilibrium constants wereobtained and from these the reduction potentials