Irradiation of Dihydropyrimidines

Journal Article · Sun Dec 31 23:00:00 EST 1967 · Radiation Research

DOI:https://doi.org/10.2307/3572250· OSTI ID:4482195

Snipes, Wallace ^[1]; Bernhard, William ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States)

The conversion of dihydrouracil to uracil, dihydrothymine to thymine, and dihydro-6-methyl uracil to 6-methyl uracil by gamma irradiation both in aqueous solution and in the solid state has been studied. In aqueous media, G values for the conversion process in dihydropyrimidine solutions (1 mg/ml) bubbled with oxygen, nitrous oxide, and nitrogen were 2.55, 2.27, and 0.73, respectively, for uracil; 2.17, 1.78, and 0.41 for thymine; and 2.40, 2.25, and 1.43 for 6-methyl uracil. In the solid state, G values for uracil, thymine, and 6-methyl uracil were 1.0, 0.9, and 0.9, respectively. The effect of dihydrouracil concentration on the G value for uracil production in oxygenated aqueous solution was measured. Free radicals formed in polycrystalline dihydrothymine and dihydro-6-methyl uracil were studied by electron spin resonance spectroscopy. Dose-response relationships for radical production and destruction by the radiation were measured. The G values for radical production in dihydrothymine and dihydro-6-methyl uracil were found to be 0.85 and 0.45, respectively. Finally, the close correspondence between the G values for radical production in these dihydropyrimidines and the G values for their conversion to unsaturated compounds in the solid state suggests the possibility that the radicals are intermediates in this process.

• Research Organization: Pennsylvania State Univ., University Park, PA (United States)
• Sponsoring Organization: US Atomic Energy Commission (AEC); National Aeronautics and Space Administration (NASA)
• NSA Number: NSA-22-016595
• OSTI ID: 4482195
• Report Number(s): NYO--3799-3
• Journal Information: Radiation Research, Journal Name: Radiation Research Journal Issue: 1 Vol. 33; ISSN 0033-7587
• Publisher: Radiation Research Society
• Country of Publication: United States
• Language: English

Related Subjects

ABUNDANCE
ELECTRON SPIN RESONANCE
ELECTRONS
FREE RADICALS
G-VALUE
GAMMA RADIATION
Gamma Radiation Effects
HETEROCYCLICS
HYDROGEN
Hydrouracil
IRRADIATION
METHYL RADICALS
NITROGEN
NITROGEN OXIDES
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OXYGEN
PYRIMIDINES
RADIATION CHEMISTRY
RADIATION DOSES
RADIATION EFFECTS
REACTION KINETICS
RESONANCE
Radiation & Nuclear Chemistry
Radiation Effects
SOLIDS
SPIN
Thymine
URACIL
Uracil
WATER