Electron spin resonance of spin-trapped radicals in. gamma. -irradiated aqueous uracil solutions. Chromatographic separation of radicals

Journal Article · Wed Mar 16 23:00:00 EST 1983 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100229a028· OSTI ID:6107485

Makino, K; Mossoba, M M; Riesz, P

Air-saturated aqueous uracil solutions were ..gamma.. irradiated at room temperature in the presence of 2-methyl-2-nitrosopropane (the spin trap) (MNP). The resulting radicals were separated subsequently by high-performance liquid chromatography and detected by ESR. With a phosphate buffer (pH 7.0), the spin adduct, NH-C(=O)-NH-C(=O)-CH(-OH)-CH-N(O.)-/sup t/Bu (A), was obtained while with a Na/sub 2/HPO/sub 4/-NaOH buffer (pH 11.0), the spin adduct (B) which has the same chemical structure as (A) but shows a different ESR spectrum from that of (A) was separated. The spin adducts, A and B, were found to be cis-trans isomers of each other. The assignments for these spin adducts were confirmed by studying the ESR spectra of the spin adducts in H/sub 2/O and D/sub 2/O at various pH and pD values and also by investigating the ESR spectra obtained from ..gamma..-irradiated aqueous solutions containing uracil-5-d. In addition to these spin adducts, NH-C(=O)-NH-C(=O)-CH-(-N(O.)-/sup t/Bu)-CH-OH (C) was obtained. The ESR spectra of A, B, and C were compared with those obtained from the uv-irradiated aqueous dihydrouracil solutions containing MNP and H/sub 2/O/sub 2/ at various pH values and were found not to be due to H-addition products at the C5 or C6 of uracil. The spin adducts, A, B, and C, are formed from the radicals generated by addition of hydroxyl radicals to the 5,6 double bond of uracil.

• Research Organization: National Inst. of Health, Bethesda, MD
• OSTI ID: 6107485
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 87:6; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ALKANES
AQUEOUS SOLUTIONS
AZINES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
CHROMATOGRAPHY
DATA
DISPERSIONS
ELECTROMAGNETIC RADIATION
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
GAMMA RADIATION
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
HYDROXY COMPOUNDS
INFORMATION
IONIZING RADIATIONS
LIQUID COLUMN CHROMATOGRAPHY
MAGNETIC RESONANCE
MIXTURES
NITROSO COMPOUNDS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PH VALUE
PROPANE
PYRIMIDINES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
RESONANCE
SEPARATION PROCESSES
SOLUTIONS
SPECTRA
TRAPPING
TRAPS
URACILS