1203661-21-5Relevant articles and documents
Generation of 2′-deoxyadenosine N6-aminyl radicals from the photolysis of phenylhydrazone derivatives
Kuttappan-Nair, Vandana,Samson-Thibault, Francois,Wagner, J. Richard
experimental part, p. 48 - 54 (2011/01/12)
Nitrogen-centered radicals are major species generated by the addition of hydroxyl radicals and the one-electron oxidation of adenine derivatives. Aminyl radicals are also generated in the decomposition of adenine chloramines upon reaction of hypochlorite. Here, we report the photochemistry of modified 2′-deoxyadenosine (dAdo) containing photoactive hydrazone substituents as a model to investigate the chemistry of dAdo N6-aminyl radicals. Derivatives of dAdo containing a phenylhydrazone moiety at N6 displayed UV absorption between 300 and 400 nm. Upon UV photolysis in the presence of a H-donor, that is, glutathione, two major products were formed, dAdo and benzaldehyde, indicating efficient homolytic cleavage to dAdo N 6-aminyl radicals and benzylidene iminyl radicals. dAdo N 6-phenylhydrazone was photolyzed in the presence of a molar excess of nonmodified dAdo to mimic the reactions taking place in DNA, and the major photoproducts were identified by high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance. The formation of 2-(benzylideneamino)-2′-deoxyadenosine as well as a more extensive oxidation product may be explained by the recombination of initial dAdo N 6-aminyl and benzylidene iminyl radicals. The formation of 2′-deoxyinosine may be explained by hydrolytic deamination of dAdo N 6-aminyl radicals. Interestingly, a dimeric product containing two dAdo moieties was identified in the photolysis mixture. The present studies demonstrate the ability of dAdo N6-aminyl radicals to undergo H-abstraction to give dAdo, deamination to give 2′-deoxyinosine, and addition to the adenine moiety to give dimers.
