Radiation chemistry of the nucleobases

The free-radical chemistry of the nucleobases has been reviewed in the past [1-5]. The goal of this Chapter is to present an update in a more general sense a more detailed discussion of the topic will be published in a different context [6]. The present Chapter is centered on the radiation-induced free-radical chemistry of the nucleobases and some of their derivatives which comprise, on the one hand, the nucleosides and nucleotides, and on the other hand, model compounds such as some methylated nucleobases. 

The effect of other inorganic radicals on the nucleobases, apart from the water radicals mentioned above, has repeatedly been studied, for instance the sulfate radical which has been used to generate nucleobase radical cations with the aim to mimic the direct effect of ionizing radiation on DNA. Carbon-centred 

In aqueous solution, the nucleobases react with the OH radical and the solvated electron at close to diffusion-controlled rates, while the H atom reacts one order of magnitude more slowly (Table 1). In nucleosides and nucleotides, of these three species only the OH radical shows a moderate inclination of reacting with the sugar moiety, typically in the range of 10 to 20% of the total. 

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