2-Aminopurine radical cation

As with other reducing agents, G reacts with 02 (Chap. 10.2) which is the most abundant freely diffusing peroxyl radical. Upon two-photon excitation of a 2-aminopurine-containing ss- and dsODN in air-saturated solutions, photoionization leads to the formation of eaq (and subsequently 02 ) and the 2-amino-purine radical cation oxidizes a neighboring G (leading to G plus H+ Misiaszek et al. 2004). G and 02 react with one another (ssDNA k = 4.1 x 108 dm3 mol-1 s 1 dsDNA 2.7 x 108 dm3 mol-1 sH). In the majority of these events G is reformed, but with an efficiency of 15% Iz and, to a minor extent, 8-oxo-G are formed. The suggested mechanism is shown in Chapter 10.2. 

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