Free radicals from purine nucleosides after hydroxyl radical attack
Free radicals from imidazole, caffeine, guanosine, deoxyguanosine, inosine, adenosine, deoxyadenosine, and adenine, as well as ..beta..-D-ribose and ..beta..-D-deoxyribose, were generated by reaction with OH from H/sub 2/O/sub 2/-Ti/sup 3 +/ at pH 1.5-2 and studied by ESR, using a computerized, Q-band, fast-flow system. Purine base radicals, plus sugar radicals in nucleosides, were always observed. Prior deuteration of C8 made possible the assignment of the observed 10-15 gauss doublet splitting to the C8 proton in guanine derivatives, and to the C2 proton in adenine derivatives and inosine. Hueckel calculations (and INDO in a few cases) on possible radical species suggest that hydroxyl addition on nitrogens in the purine ring or on C5 may be responsible for the species which are observed. In imidazole, the radical species is a hydroxyl adduct. An anomalous effect of deuteration of C8 on the spectrum obtained with caffeine is also reported.
- Research Organization:
- Brookhaven National Lab., Upton, NY
- OSTI ID:
- 7305290
- Journal Information:
- Radiat. Res.; (United States), Vol. 65
- Country of Publication:
- United States
- Language:
- English
Similar Records
Kinetics and mechanism of carbon-8 methylation of purine bases and nucleosides by methyl radical
DNA 3' pp 5' G de-capping activity of aprataxin: effect of cap nucleoside analogs and structural basis for guanosine recognition
Related Subjects
ADENOSINE
CHEMICAL REACTIONS
CAFFEINE
GUANOSINE
HYDROXYL RADICALS
IMIDAZOLES
INOSINE
DEUTERIUM
ELECTRON SPIN RESONANCE
ISOTOPE EFFECTS
RADICALS
AZOLES
DRUGS
HETEROCYCLIC COMPOUNDS
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEI
NUCLEOSIDES
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PURINES
RESONANCE
RIBOSIDES
STABLE ISOTOPES
XANTHINES
400600* - Radiation Chemistry