Free radicals from single crystals of deoxyguanosine 5?-monophosphate (Na Salt) irradiated at low temperatures

• DOI: 10.1007/bf01211360
• Publication Date: 2005-02-25T11:24:30Z
• Authors: B. Rakvin; J. N. Herak; K. Voit; J. Huttermann
• Keywords: Deoxyguanosine

In single crystals of the DNA nucleotide 2'deoxyguanosine-5'phosphate (5'dGMP) X- or gamma-irradiated at 4.2 K or 15 K, two primary radical species can be discriminated and assigned to the cation and anion of the guanine base, G(+) and G(-). Both species are unstable. G(-) partially transforms into a secondary radical at 4.2 K, the latter being the precursor to the dominant 300 K species formed by net H-addition to carbon C8. The secondary radical, together with another intermediate appearing at 77 K and perhaps connected with the anion decay could not be structurally identified. The guanine cation G(+) transforms upon annealing to temperatures above 77 K into a more stable species by deprotonation at position N1.