Tautomers of One-Electron Oxidized Guanosine

8-Bromoguanine derivatives, such as 1a and 1b, capture
electrons (eaq
) with quantitative formation of the corresponding
debrominated nucleosides[1,2] and, therefore, they
are efficient detectors of excess electron-transfer processes.[3]
Indeed, in two recent papers 8-bromo-2'-deoxyguanosine
(1b) was incorporated in a varietyof single- and doublestranded
oligonucleotides and G-quadruplexes, and the
reaction with eaq
indicated that excess electron transfer is
effective.