Radiation damage to nucleosides and nucleotides. I. An ESR study of uridine-5'-phosphate. 2Na/sup +/ single crystals

Journal Article · Fri Feb 01 04:00:00 EST 1980 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575395· OSTI ID:5300562

Sagstuen, E

Single crystals of the disodium salt of uridine-5'-phosphate were irradiated by 4.0-MeV electrons and studied by electron spin resonance spectroscopy in the temperature range 77 to 310 K. At 77 K two resonances were observed. The dominating resonance (I) is ascribed to the electron adduct (anion) radical of the uracil base. The main hyperfine interaction observed is a coupling between the unpaired electron and the proton bonded to C/sub 6/. The other resonance (II) exhibits a large g-value anisotropy and two almost isotropic doublet couplings. This resonance is probably due to a secondary alkoxy-type radical formed by a net loss of hydrogen from O/sub 3/' in the sugar moiety. At 270 K three resonances were observed. One (III) is due to a radical formed by hydrogen abstraction from C/sub 5'/ in the sugar moiety, whereas the other two (IV,V) are probably hydrogen addition radicals at the uracil base. Radical IV is the dihydrouracil-5-yl radical formed by a net hydrogen addition to the C/sub 6/ position, whereas radical V tentatively is ascribed to the 6-yl radical. The light-induced conversion V ..-->.. IV took place at 270 K, whereas the reverse heat-induced process was not observed in the temperature range studied. Preliminary annealing studies of crystals irradiated at 77 K suggest that the radical reaction I ..-->.. IV takes place at approximately 130 K and the reaction II ..-->.. III at 150 K.

• Research Organization: Univ. of Oslo, Norway
• OSTI ID: 5300562
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 81:2; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
560111* -- Radiation Effects on Biochemicals-- In Vitro-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AZINES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
ELECTRON SPECTROSCOPY
ELECTRON SPIN RESONANCE
ELECTRONS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INJURIES
KINETICS
LEPTONS
MAGNETIC RESONANCE
MEV RANGE
MEV RANGE 01-10
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIMIDINES
RADIATION EFFECTS
RADIATION INJURIES
RADICALS
RADIOSENSITIVITY
REACTION KINETICS
RESONANCE
RIBOSIDES
SPECTROSCOPY
URACILS
URIDINE