67145-02-2Relevant academic research and scientific papers
Sonochemical transformation of thymidine: A mass spectrometric study
Chandran, Jisha,Aravind, Usha K.,Aravindakumar
, p. 178 - 186 (2015/06/02)
Abstract Ultrasound is extensively used in medical field for a number of applications including targeted killing of cancer cells. DNA is one of the most susceptible entities in any kind of free radical induced reactions in living systems. In the present work, the transformation of thymidine (dT) induced by ultrasound (US) was investigated using high resolution mass spectrometry (LC-Q-ToF-MS). dT was subjected to sonolysis under four different frequencies (200, 350, 620 and 1000 kHz) and at three power densities (10.5, 24.5 and 42 W/mL) in aerated as well as argon saturated conditions. A total of twenty modified nucleosides including non-fully characterized dT dimeric compounds were detected by LC-Q-ToF-MS. Out of these products, seven were obtained only in the argon atmosphere and two only in the aerated conditions. Among the identified products, there were base modified products and sugar modified products. The products were formed by the reaction of hydroxyl radical and hydrogen atom. Under aerated conditions, the reactions proceed via the formation of hydroperoxides, while in argon atmosphere disproportionation and radical recombinations predominate. The study provides a complete picture of sonochemical transformation pathways of dT which has relevance in DNA damage under ultrasound exposure.
Reactivity of 5,6-dihydro-5-hydroxythymid-6-yl-generated via photoinduced single electron transfer and the role of cyclohexa-1,4-diene in the photodeoxygenation process
Barvian,Barkley,Greenberg
, p. 4894 - 4904 (2007/10/02)
The major reactive species formed via reaction of hydroxyl radical and the pyrimidine nucleoside thymidine, 5,6-dihydro-5-hydroxythymid-6-yl (1), is generated photochemically under anaerobic conditions from 6 via photoinduced single electron transfer. Und
Independent Generation of the Major Adduct of Hydroxyl Radical and Thymidine. Examination of Intramolecular Hydrogen Atom Transfer in Competition With Thiol Trapping.
Barvian, Mark R.,Greenberg, Marc M.
, p. 6057 - 6060 (2007/10/02)
5,6-Dihydro-5-hydroxythymid-6-yl (1) has been generated from 2 via photoinduced electron transfer from N-methylcarbazole.In agreement with prior reports, deuterium incorporation in conjunction with (2)H NMR analysis of 5,6-dihydro-5-hydroxythymidine (3) f
Identification of the Products resulting from the Direct effects of γ-Radiation on Thymidine
Shaw, Anthony A.,Voituriez, Lucienne,Cadet, Jean,Gregoli, Silvano,Symons, Martyn C.
, p. 1303 - 1308 (2007/10/02)
The products formed upon γ-irradiation of thymidine in frozen aqueous solution have been identified.These products may all be explained in terms of the fates of now well documented primary charged radical species, and our results complement well those of previous e.s.r. studies on those primary and secondary radicals.In order to probe the mechanisms of formation of the major products, we have carried out experiments using heavy isotopes, including deuterium oxide and (18)O2.The radical cation undergoes both hydration, yielding the four isomers of 6-hydroxy-5,6-dihydrothymidine, and deprotonation at the methyl group to yield 5-hydroxymethyl-2'-deoxyuridine.As expected, the radical anion reacts primarily by protonation at C-6 to yield the (5R)- and (5S)-diastereoisomers of 5,6-dihydrothymidine and 5-hydroxy-5,6-dihydrothymidine.Excitation processes were shown to occur by the observation of the thymidine cyclobutane dimers.The release of significant amounts of thymine and 2-deoxy-D-ribono-1,4-lactone indicates the formation of radicals centred within the sugar moiety.The proposed role of the initial charged radicals in the formation of certain products has been supported by quantitative experiments carried out using compounds expected to be electron scavengers and electron donors with respect to thymidine.Finally, subsequent to our earlier paper on the e.s.r. identification of the radicals formed upon irradiation of thymidine bromohydrin in frozen aqueous solution, we have isolated the products formed on annealing and identified them as thymidine and 5-hydroxymethyl-2'-deoxyuridine.We discuss their mechanisms of formation.
