5-Methyl deoxycytidine

Scheme 3 Main reactions of the radical cation of 5-methyl-2 -deoxycytidine in aerated aqueous solutions...

Fig. 2. Total fluorescence decays of 5-methyl-2 -deoxycytidine (5m dC) (filled circles) and 2 -deoxycytidine (dC) (open circles) recorded at 330 nm. The excitation wavelength was 267 nm.

Downfield chemical shift changes are given as negative numbers and are in cycles per second. In all cases except cytidine and 5 -methyl-2 -deoxycytidine, inhibitor concentrations were sufficient to saturate the enzyme between pH 5 and 7. [Reproduced from Meadows et al. (465).]... 

Bianchini F, Hall J, Donato F, Cadet J (1996) Monitoring urinary excretion of 5-hydroxymethyluracil for assessment of oxidative DNA damage and repair. Biomarkers 1 178-184 Bienvenu C, Wagner JR, Cadet J (1996) Photosensitized oxidation of 5-methyl-2 -deoxycytidine by 2-methyl-1,4-naphthoquinone characterization of 5-(hydroperoxymethyl)-2 -deoxycytidine and stable methyl group oxidation products. J Am Chem Soc 118 11406-11411 Bothe E, Behrens G, Schulte-Frohlinde D (1977) Mechanism of the first order decay of 2-hydroxypro-pyl-2-peroxyl radicals and of O2 formation in aqueous solution. Z Naturforsch 32b 886-889 Bothe E, Deeble DJ, Lemaire DGE, Rashid R, Schuchmann MN, Schuchmann H-P, Schulte-Frohlinde D, Steenken S, von Sonntag C (1990) Pulse-radiolytic studies on the reactions of S04 with uracil derivatives. Radiat Phys Chem 36 149-154... 

Fig. 11.—Ultraviolet Absorption Spectrum of 5 -Methyl-2-deoxycytidine at pH Values Indicated. (Adapted from Fox and coworkers.6 )...

The photoinduced intramolecular electron transfer reactions of some poly-(ethylene glycol)-linked 9-aminoacridine-benzoate electron donor-acceptor systems have been described. Photosensitized oxidation of 5-methyl-2 -deoxy-cytidine using menadione (2-methylnaphthalene-l,4-dione) gives 5,6-dihydroxy-5,6-dihydro-5-methyl-2 -deoxycytidine in what is thought to be an electron... 

Cytosine arabinoside is enzymatically deaminated in the liver. The resulting product, uracil arabinoside, no longer possesses antileukaemia or antiviral activity [291, 292, 340, 341]. A variety of cytosine derivatives have been studied as deaminase inhibitors. The most active of these was a 4-hydroxylamino derivative, iV -hydroxy-5-methyl-2 -deoxycytidine [342]. 

Direct hydrogen atom abstraction occurs less frequently from the nucle-obases, despite the expected modest carbon—hydrogen bond dissociation energy of the carbon—hydrogen bonds in the methyl groups of thymidine and 5-methyl-2 -deoxycytidine due to resonance stabilization of the incipient radicals. The respective radicals are also formed by deprotonation of the nucleobase radical cations, intermediates involved in electron transfer that are produced via one-electron oxidation. Amine radicals are also postulated as intermediates produced from the spontaneous decomposition of chloramines that arise from reactions of nucleosides with hypochlorous acid." " However, the majority of nucleobase radical intermediates arise from the... 

Deoxyuridinyl)methyl radical (74) and the respective radical from 5-methyl-2 -deoxycytidine have not been proposed to yield strand breaks. However, 74 and other nucleobase radicals have been impHcated in reactions with adjacent nucleotides, resulting in two contiguously damaged nucleotides (eg 15). Such lesions are typically referred to as tandem lesions.Tandem lesions are a subset of clustered lesions, which are defined as two or more damaged nucleotides within one to two helical turns. Clustered lesions are of particular interest to radiation scientists because of their formation via HO spurs and the difficulties that they pre-sent for DNA repair. In addition, 74 has been invoked as an inter-... 

Lalitha HN, Ramakumar S, Viswamitra MA (1989) Structure of 5-methyl-2 -deoxycytidine 5 -monophosphate dihydrate. Acta Crystallogr Sect C Cryst Struct Commun 45 1652-1655. doi 10.1107/S0108270189005445... 

W. L. Sung, Chemical conversion of thymidine into 5-methyl-2 -deoxycytidine,... 

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