Oxidative damage thymidine

In a study related to oxidatively-damaged thymidine units in DNA, the bromohydrin (206), on exposure to light, heat or radical initiators, underwent the chemistry in Scheme (26), where the formation of p-furanose product represents a process of self-repair.286... 

Production of Mucosal Damage 2.3.1.2.1 Cell culture Stimulated neutrophils are known to be cytotoxic to cells in vitro (Dull et al., 1987 Dallegri et al., 1990 Grisham et al., 1990b). Several in vitro systems have been used to demonstrate oxidative damage to intestinal cells. Xanthine/XO increased Cr release and decreased [ H]thymidine uptake by IEC-18 small intestinal epithelial cell monolayers in a dose-dependent manner (Ma et al., 1991). Rat enterocytes show decreased trypan blue exclusion and increased protein release when incubated with neutrophils stimulated... 

Martinez GR, Medeiros MHG, Ravanat J-L, Cadet J, Di Mascio P (2002) [0ls]-Labeled singlet oxygen as a tool for mechanistic studies of 8-oxo-7,8-dihydroguanine oxidative damage detection of spiroiminodihydantoin, imidazolone and oxazolone derivatives. Biol Chem 383 607-617 Martini M, Termini J (1997) Peroxy radical oxidation of thymidine. Chem Res Toxicol 10 234-241 Merenyi G, Lind J, Shen X (1988) Electron transfer from indoles, phenol, and sulfite (S032T to chlorine dioxide (CICV). J Phys Chem 92 134-137... 

The templating properties of oligonucleotides containing 5-formyl-2 -deoxycytidine (fC), which may be introduced into DNA by oxidative damage of thymidine, have been examined with the Klenow fragment. It was found that fC directed the incorporation of dATP and TTP, thus giving rise to CG TA transitions as well as CG AT transversions. ... 

Cathcart, R., Schwiers, E., Saul, R.L. and Ames, B.N. (1984) Thymine glycol and thymidine glycol in human and rat urine a possible assay for oxidative damage. Proc. Natl. Acad. Sci. USA 81 5633-5637. 

The DNA lesion 8,5 -cyclo-2 -dG, formed by attack of hydroxyl radicals, contains damage to both base and sugar, and is therefore repaired by nucleotide excision repair enzymes, and is involved in diseases with defective nucleotide excision repair. A mass spectroscopic assay has been developed for the quantitation of the lesion after enzymatic separation of the 5 (R) and 5 (S) isomers. The thermodynamic stability of ODNs containing the oxidative lesion, 2-hydroxy-dA has been examined. It was shown that when the lesion was in the middle of a DNA duplex it behaved as a universal base, in that there was no dilference in Tm when opposite any of the canonical bases. On the other hand, when it was near the termini, there was a preference for base pairing with thymidine, but it also formed base pairs with other nucleotides which was sequence dependent. The extent of oxoprenylation by malondialdehyde or adenine propenal has been investigated in DNA, see (139). ssDNA was found to be more sensitive to oxoprenylation, and supercoiled-DNA more susceptible than linearised plasmid DNA. A variety of intercalators were used, some of which inhibit oxoprenylation, e.g. netropsin, whilst others, like ethidium bromide, caused enhanced oxoprenylation. 

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