20433-38-9Relevant articles and documents
Analysis of oxidative cytosine products in DNA exposed to ionizing radiation
Wagner, J. R.
, p. 1280 - 1286 (2007/10/02)
From ionizing radiation studies, we have previously characterized a large number of modifications of cytosine and 2'-deoxycytidine which arise by way of hydroxyl radical or base radical cation reactions.However, it remains a great challenge today to detect and quantitate these lesions in DNA.In the present work, I have developed a method for the analysis of six oxidation products of cytosine in DNA using HF acid hydrolysis and gas chromatography/mass spectrometry with isotopic dilution.The analysis of gamma-irradiated DNA indicated that uracil 5,6-glycols 5-hydroxyuracil and 5-hydroxyhydantoin are the major stable decomposition products of cytosine residues, whereas alloxane and 1-carbamoyl-2-oxo-4,5-dihydroxy-imidazolidine are formed in comparatively lower yields.These results suggest that the major pathway of OH radical induced decomposition of cytosine in DNA involves initial deamination of intermediate 5-hydroxy-6-hydroperoxides. - Keywords: Oxidative DNA damage, mass spectrometry, isotopic dilution, mutagenesis.
EFFECT OF COPPER(II) IONS ON THE γ-RADIOLYSIS OF URACIL
Bhattacharyya, Sudhindra N.,Mandal, Parikshit C.
, p. 2613 - 2630 (2007/10/02)
Radiation sensitization of uracil (Ura) by CuII ions has been investigated using cobalt-60 γ-rays.In N2O-saturated solution, when no additive is present, the base degradation yield, G(-Ura), is only ca. 3.3, but when CuII ions are added in either a free or complexed state to the solution before irradiation, G(-Ura) is found to increase to ca. 5.1.The enhanced degradation of the base is derived from the oxidized transient, e.g.UraOH+, although reduction of CuII to CuI has been ascribed to all the primary adducts, e.g.UraH, UraOH and Ura-.Glycol and isobarbituric acid constitute the major products of radiolysis, which are derived from the oxidized UraOH+ species.Hydroxydihydrouracil and its dimer have also been detected in significant yields when the radiolysis is carried out at comparitively high absorbed doses.The formation of these products has been ascribed to a secondary reaction between UraOH and CuI which proceeds through the intermediate formation of a Cu-C bond.
PROMOTION EFFECT OF 2,2,6,6-TETRAMETHYLPIPERIDINE-1-OXYLS ON THE RADIOLYTIC HYDROXYLATION OF THYMINE IN DEAERATED AQUEOUS SOLUTION
Kagiya, Tsutomu,Kimura, Ryoji,Komuro, Chikara,Sakano, Koichi,Nishimoto, Sei-ichi
, p. 1471 - 1474 (2007/10/02)
Remarkable promotion of the hydroxylation of thymine to give thymine glycol with almost complete depression of side reactions by 2,2,6,6-tetramethylpiperidine-1-oxyl (TMPO.) derivatives was observed in the γ-radiolyses of the N2- and N2O-saturated aqueous solutions.In the O2-saturated solution, TMPO. depressed the thymine conversion close to the level under N2 while promoted the formation of thymine glycol to some extent by decreasing side reactions.
