5116-24-5Relevant articles and documents
Catalytic Space Engineering as a Strategy to Activate C-H Oxidation on 5-Methylcytosine in Mammalian Genome
Dey, Debasis,Islam, Kabirul,Sappa, Sushma,Sudhamalla, Babu
supporting information, p. 11891 - 11896 (2021/08/20)
Conditional remodeling of enzyme catalysis is a formidable challenge in protein engineering. Herein, we have undertaken a unique active site engineering tactic to command catalytic outcomes. With ten-eleven translocation (TET) enzyme as a paradigm, we show that variants with an expanded active site significantly enhance multistep C-H oxidation in 5-methylcytosine (5mC), whereas a crowded cavity leads to a single-step catalytic apparatus. We further identify an evolutionarily conserved residue in the TET family with a remarkable catalysis-directing ability. The activating variant demonstrated its prowess to oxidize 5mC in chromosomal DNA for potentiating expression of genes including tumor suppressors.
RETRACTED ARTICLE: Divergent synthesis of 5-substituted pyrimidine 2′-deoxynucleosides and their incorporation into oligodeoxynucleotides for the survey of uracil DNA glycosylases
Tran, Ai,Zheng, Song,White, Dawanna S.,Curry, Alyson M.,Cen, Yana
, p. 11818 - 11826 (2020/11/18)
Recent studies have indicated that 5-methylcytosine (5mC) residues in DNA can be oxidized and potentially deaminated to the corresponding thymine analogs. Some of these oxidative DNA damages have been implicated as new epigenetic markers that could have profound influences on chromatin function as well as disease pathology. In response to oxidative damage, the cells have a complex network of repair systems that recognize, remove and rebuild the lesions. However, how the modified nucleobases are detected and repaired remains elusive, largely due to the limited availability of synthetic oligodeoxynucleotides (ODNs) containing these novel DNA modifications. A concise and divergent synthetic strategy to 5mC derivatives has been developed. These derivatives were further elaborated to the corresponding phosphoramidites to enable the site-specific incorporation of modified nucleobases into ODNs using standard solid-phase DNA synthesis. The synthetic methodology, along with the panel of ODNs, is of great value to investigate the biological functions of epigenetically important nucleobases, and to elucidate the diversity in chemical lesion repair.
Fluorescent Wittig reagent as a novel ratiometric probe for the quantification of 5-formyluracil and its application in cell imaging
Zhou, Qian,Li, Kun,Liu, Yan-Hong,Li, Ling-Ling,Yu, Kang-Kang,Zhang, Hong,Yu, Xiao-Qi
, p. 13722 - 13725 (2019/01/03)
The chemically selective detection of natural nucleobase modifications has been regarded as the key step in understanding their important roles in epigenetics. Herein, for the first time, we introduce a Wittig reaction into the design of reaction-based fluorescent probes for ratiometrically detecting 5fU, selectively labelling 5fU-modified DNA and imaging intracellular 5fU produced by γ-irradiation.
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.
5-Hydroxymethylcytosine and 5-formylcytosine containing deoxyoligonucleotides: Facile syntheses and melting temperature studies
Xuan, Shuguang,Wu, Qiong,Cui, Liang,Zhang, Dawei,Shao, Fangwei
supporting information, p. 1186 - 1191 (2015/03/14)
An oxidation-based synthetic approach was developed for facile preparation of 5-formyl-2′-deoxycytidine and 5-hydroxymethyl-2′-deoxycytidine phosphoramidites. Upon introducing organic solvent components and copper catalysts, C5-methyl groups of 5-methyl-2′-deoxycytidine and thymidine were readily oxidized to formyl and hydroxyl functionality, respectively. Standard solid phase DNA synthesis and conventional deprotection methods were applicable to synthesize 5-formyl- or 5-hydroxymethyl-cytosine containing DNA oligonucleotides, which were used to study the effect of epigenetic modifications on DNA thermal dynamic stability.
One-step to get 5-azidomethyl-2′-deoxyuridine from 5-hydroxymethyl-2′-deoxyuridine and detection of it through click reaction
Xu, Xiaowei,Yan, Shengyong,Hu, Jianlin,Guo, Pu,Wei, Lai,Weng, Xiaocheng,Zhou, Xiang
, p. 9870 - 9874 (2013/10/22)
Nowadays a few ways to synthesize 5-azidomethyl-2′-deoxyuridine from 5-hydroxymethyl-2′-deoxyuridine have been reported. But none of them was one-step. And many of them need to protect the hydroxyl group on the pentose ring. The detection of 5-hydroxymethyl-2′-deoxyuridine is also very important in many biological processes. However few fluorescence detection strategies have been tried to do this. Herein, we reported a one-step protocol to synthesize 5-azidomethyl-2′-deoxyuridine, which was then used for detecting 5-hydroxymethyl-2′-deoxyuridine through a click reaction.
Deamination, oxidation, and C-C bond cleavage reactivity of 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxycytosine
Schiesser, Stefan,Pfaffeneder, Toni,Sadeghian, Keyarash,Hackner, Benjamin,Steigenberger, Barbara,Schroeder, Arne S.,Steinbacher, Jessica,Kashiwazaki, Gengo,Hoefner, Georg,Wanner, Klaus T.,Ochsenfeld, Christian,Carell, Thomas
, p. 14593 - 14599 (2013/10/22)
Three new cytosine derived DNA modifications, 5-hydroxymethyl-2′- deoxycytidine (hmdC), 5-formyl-2′-deoxycytidine (fdC) and 5-carboxy-2′-deoxycytidine (cadC) were recently discovered in mammalian DNA, particularly in stem cell DNA. Their function is currently not clear, but it is assumed that in stem cells they might be intermediates of an active demethylation process. This process may involve base excision repair, C-C bond cleaving reactions or deamination of hmdC to 5-hydroxymethyl-2′- deoxyuridine (hmdU). Here we report chemical studies that enlighten the chemical reactivity of the new cytosine nucleobases. We investigated their sensitivity toward oxidation and deamination and we studied the C-C bond cleaving reactivity of hmdC, fdC, and cadC in the absence and presence of thiols as biologically relevant (organo)catalysts. We show that hmdC is in comparison to mdC rapidly oxidized to fdC already in the presence of air. In contrast, deamination reactions were found to occur only to a minor extent. The C-C bond cleavage reactions require the presence of high concentration of thiols and are acid catalyzed. While hmdC dehydroxymethylates very slowly, fdC and especially cadC react considerably faster to dC. Thiols are active site residues in many DNA modifiying enzymes indicating that such enzymes could play a role in an alternative active DNA demethylation mechanism via deformylation of fdC or decarboxylation of cadC. Quantum-chemical calculations support the catalytic influence of a thiol on the C-C bond cleavage.
One-pot approach to functional nucleosides possessing a fluorescent group using nucleobase-exchange reaction by thymidine phosphorylase
Hatano, Akihiko,Kurosu, Masayuki,Yonaha, Susumu,Okada, Munehiro,Uehara, Sanae
, p. 6900 - 6905 (2013/10/08)
Herein, we describe β-selective coupling between a modified uracil and a deoxyribose to produce functionalized nucleosides catalyzed by thymidine phosphorylase derived from Escherichia coli. This enzyme mediates nucleobase-exchange reactions to convert unnatural nucleosides possessing a large functional group such as a fluorescent molecule, coumarin or pyrene, linked via an alkyl chain at the C5 position of uracil. 5-(Coumarin-7-oxyhex-5- yn)uracil (C4U) displayed 57.2% conversion at 40% DMSO concentration in 1.0 mM phosphate buffer pH 6.8 to transfer thymidine to an unnatural nucleoside with C4U as the base. In the case of using 5-(pyren-1-methyloxyhex-5-yn)uracil (P4U) as the substrate, TP also could catalyse the reaction to generate a product with a very large functional group at 50% DMSO concentration (21.6% conversion). We carried out docking simulations using MF myPrest for the modified uracil bound to the active site of TP. The uracil moiety of the substrate binds to the active site of TP, with the fluorescent moiety linked to the C5 position of the nucleobase located outside the surface of the enzyme. As a consequence, the bulky fluorescent moiety binding to uracil has little influence on the coupling reaction.
Deconvoluting the reactivity of two intermediates formed from modified pyrimidines
Weng, Liwei,Horvat, Sonia M.,Schiesser, Carl H.,Greenberg, Marc M.
supporting information, p. 3618 - 3621 (2013/08/23)
Generation of the 5-(2′-deoxyuridinyl)methyl radical (6) was reexamined. Trapping by 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl confirms that 6 is generated. However, trapping by methoxyamine reveals that the respective carbocation (10) is also produce
Oxidation and reduction of the 5-(2-Deoxyuridinyl)methyl radical
Lin, Gengjie,Li, Lei
, p. 5594 - 5598 (2013/06/27)
Sleeping beauty: The 5-(2-Deoxyuridinyl)methyl radical 1 is a key intermediate in the thymine oxidative reaction mediated by reactive oxygen species. Evidence is presented that 1 is prone to both oxidation and reduction reactions at the absence of O2. These results question the current paradigm and suggest that the redox chemistry of 1, which has been largely overlooked in the past, may play a major role in determining the fate of 1. Copyright
