Nucleobases, Nucleosides and Nucleotides - Free-Radical-Induced DNA Damage and Its Repair - page 216

In the original mechanistic concept, a free radical cation, reaction (37), has been
postulated (Catterall et al. 1992). Based on circumstantial evidence, the con-
comitant release of HSO 4 − is now favored [reaction (36); Aravindakumar et al.
2003].
Cyd, in contrast, gives rise to a sugar-centered radical. The mechanism
proposed by (Catterall et al. 1992) has been modified by Aravindakumar et al.
(2003) [reactions (42)−(47)] insofar as route (42) is now favored over (43) fol-
lowed by (44).