- Ability of hypochlorous acid and N -chloramines to chlorinate DNA and its constituents
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Myeloperoxidase is a heme enzyme released by activated phagocytes that is responsible for the generation of the strong oxidant hypochlorous acid (HOCl). Although HOCl has potent bactericidal properties and plays an important role in the human immune system, this oxidant also causes damage to tissues, particularly under inflammatory conditions. There is a strong link between chronic inflammation and the incidence of many cancers, which may be associated with the ability of HOCl and related oxidants such as N-chloramines to damage DNA. However, in contrast to HOCl, little is known about the reactivity of N-chloramines with DNA and its constituents. In this study, we examine the ability of HOCl and various N-chloramines to form chlorinated base products on nucleosides, nucleotides, DNA, and in cellular systems. Experiments were performed with N-chloramines formed on Nα-acetyl-histidine (His-C), Nα-acetyl-lysine (Lys-C), glycine (Gly-C), taurine (Tau-C), and ammonia (Mono-C). Treatment of DNA and related materials with HOCl and His-C resulted in the formation of 5-chloro-2'-deoxycytidine (5CldC), 8-chloro-2'-deoxyadenosine (8CldA) and 8-chloro-2'-deoxyguanosine (8CldG). With the nucleosides, 8CldG was the favored product in each case, and HOCl was the most efficient chlorinating agent. 5Cl(d)C was the most abundant product on exposure of the nucleotides and DNA to HOCl and His-C, with only low levels of chlorinated products observed with Lys-C, Gly-C, Tau-C, and Mono-C. 5CldC was also formed on exposure of smooth muscle cells to either HOCl or His-C. Cellular RNA was also a target for HOCl and His-C, with evidence for the formation of 5-chloro-cytidine (5ClC). This study shows that HOCl and the model N-chloramine, His-C, are able to chlorinate cellular genetic material, which may play a role in the development of various inflammatory cancers.
- Stanley, Naomi R.,Pattison, David I.,Hawkins, Clare L.
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- DNA duplexes and triplex-forming oligodeoxynucleotides incorporating modified nucleosides forming stable and selective triplexes
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We have previously reported DNA triplexes containing the unnatural base triad G-PPI·C3, in which PPI is an indole-fused cytosine derivative incorporated into DNA duplexes and C3 is an abasic site in triplex-forming oligonucleotides (TFOs) introduced by a propylene linker. In this study, we developed a new unnatural base triad A-ψ·CR1 where ψ and CR1 are base moieties 2′-deoxypseudouridine and 5-substituted deoxycytidine, respectively. We examined several electron-withdrawing substituents for R1 and found that 5-bromocytosine (C Br) could selectively recognize ψ. In addition, we developed a new PPI derivative, PPIMe, having a methyl group on the indole ring in order to achieve selective triplex formation between DNA duplexes incorporating various Watson-Crick base pairs, such as T-A, C-G, A-ψ, and G-PPIMe, and TFOs containing T, C, CBr, and C3. We studied the selective triplex formation between these duplexes and TFOs using UV-melting and gel mobility shift assays.
- Kanamori, Takashi,Masaki, Yoshiaki,Mizuta, Masahiro,Tsunoda, Hirosuke,Ohkubo, Akihiro,Sekine, Mitsuo,Seio, Kohji
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supporting information; experimental part
p. 1007 - 1013
(2012/04/10)
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- Highly efficient method for C-5 halogenation of pyrimidine-based nucleosides in ionic liquids
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A novel, highly efficient, convenient, and benign methodology for C-5 halogenation of pyrimidine-based nucleosides has been developed using N-halosuccinimides as halogenating reagents without using any catalyst in ionic liquid medium. The ionic liquids were successfully recovered and reused for all the reactions. Georg Thieme Verlag Stuttgart.
- Kumar, Vineet,Yap, Jeremy,Muroyama, Andrew,Malhotra, Sanjay V.
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experimental part
p. 3957 - 3962
(2010/03/26)
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- Detection and quantification of 5-chlorocytosine in DNA by stable isotope dilution and gas chromatography/negative ion chemical ionization/mass spectrometry
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Hypochlorous acid (HOCl) is generated from activated phagocytes during infections and inflammation. One of the major products of HOCl reaction with DNA was 5-chlorocytosine (5Cl-Cyt). In this report, a gas chromatography/negative ion chemical ionization/m
- Chen, Hauh-Jyun Candy,Row, Shin-Wei,Hong, Chia-Liang
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p. 262 - 268
(2007/10/03)
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