5626-99-3Relevant articles and documents
A Combined Experimental and Theoretical Approach to the Photogeneration of 5,6-Dihydropyrimidin-5-yl Radicals in Nonaqueous Media
Aparici-Espert, Isabel,Francés-Monerris, Antonio,Rodríguez-Mu?iz, Gemma M.,Roca-Sanjuán, Daniel,Lhiaubet-Vallet, Virginie,Miranda, Miguel A.
, p. 4031 - 4038 (2016)
The chemical fate of radical intermediates is relevant to understand the biological effects of radiation and to explain formation of DNA lesions. A direct approach to selectively generate the putative reactive intermediates is based on the irradiation of photolabile precursors. But, to date, radical formation and reactivity have only been studied in aqueous media, which do not completely mimic the microenvironment provided by the DNA structure and its complexes with proteins. Thus, it is also important to evaluate the photogeneration of nucleoside-based radicals in nonaqueous media. The attention here is focused on the independent generation of 5,6-dihydropyrimidin-5-yl radicals in organic solvent through the synthesis of new lipophilic tert-butyl ketone precursors. Formation of 5,6-dihydro-2′-deoxyuridin-5-yl and 5,6-dihydrothymidin-5-yl radicals has first been confirmed by using a new nitroxide-derived profluorescent radical trap. Further evidence has been obtained by nanosecond laser flash photolysis through detection of long-lived transients. Finally, the experimental data are corroborated by multiconfigurational ab initio CASPT2//CASSCF methodology.
Direct strand scission from a nucleobase radical in RNA
Jacobs, Aaron C.,Resendlz, Marino J. E.,Greenberg, Marc M.
supporting information; experimental part, p. 3668 - 3669 (2010/05/15)
"Chemical equation presented" RNA oxidation is important in the etiology of disease and as a tool for studying the structure and folding kinetics of this biopolymer. Nucleobase radicals are the major family of reactive intermediates produced in RNA exposed to diffusible species such as hydroxyl radical. The nucleobase radicals are believed to produce direct strand breaks by abstracting hydrogen atoms from their own and neighboring ribose rings. By independently generating the formal C5 hydrogen atom addition product of uridine in RNA, we provide the first chemical characterization of the pathway for direct strand scission from an RNA nucleobase radical. The process is more efficient under anaerobic conditions. The preference for strand scission in double-stranded RNA over single-stranded RNA suggests that this chemistry may be useful for analyzing the secondary structure of RNA in hydroxyl radical cleavage experiments if they are carried out under anaerobic conditions.
Selective fluorescence-based detection of dihydrouridine with boronic acids
Luvino, Delphine,Smietana, Michael,Vasseur, Jean-Jacques
, p. 9253 - 9256 (2008/02/10)
The first fluorescent sensing system for dihydrouridine detection is presented. Dihydrouridine is the single most frequently occurring post-transcriptional modification in tRNA from bacteria and eukaryotes. A series of 10 boronic acid derivatives was prepared and their fluorogenic behaviours towards dihydrouridine and uridine were investigated. Whereas uridine always quenches fluorescence via π-π stacking interactions, several boronic acid sensors have been found to show substantial fluorescence enhancement upon binding with dihydrouridine.
