76759-76-7Relevant academic research and scientific papers
Identification of 3, N 4-etheno-5-methyl-2′-deoxycytidine in human DNA: A new modified nucleoside which may perturb genome methylation
Nair, Jagadeesan,Godschalk, Roger W.,Nair, Urmila,Owen, Robert W.,Hull, William E.,Bartsch, Helmut
, p. 162 - 169 (2012)
Methylation of cytidine at dCpdG sequences regulates gene expression and is altered in many chronic inflammatory diseases. Inflammation generates lipid peroxidation (LPO) products which can react with deoxycytidine, deoxyadenosine, and deoxyguanosine in D
RETRACTED ARTICLE: Convenient synthesis of pyrimidine 2′-deoxyribonucleoside monophosphates with important epigenetic marks at the 5-position
Zheng, Song,Tran, Ai,Curry, Alyson M.,White, Dawanna S.,Cen, Yana
, p. 5164 - 5173 (2020/07/23)
Methyl groups of thymine and 5-methylcytosine (5mC) bases in DNA undergo endogenous oxidation damage. Additionally, 5mC residues can be enzymatically deaminated or oxidized through either genetic alterations or the newly identified epigenetic reprogramming pathway. Several methods have been developed to measure the formation of modified DNA nucleobases including 32P-postlabeling. However, the postlabeling method is often limited by the absence of authentic chemical standards. The synthesis of monophosphate standards of nucleotide oxidation products is complicated by the presence of additional functional groups on the modified bases that require complex protection and deprotection strategies. Due to the emerging interest in the pyrimidine oxidation products, the corresponding protected 3′-phosphoramidites needed for solid-phase oligonucleotide synthesis have been reported, and several are commercially available. We report here an efficient synthesis of 3′-monophosphates from 3′-phosphoramidites and the subsequent enzymatic conversion of 3′-monophosphates to the corresponding 5′-monophosphates using commercially available enzymes. This journal is
Modified immunoenriched 32P-HPLC assay for the detection of O4-ethylthymidine in human biomonitoring studies
Godschalk, Roger,Nair, Jagadeesan,Kliem, Hans-Christian,Wiessler, Manfred,Bouvier, Guy,Bartsch, Helmut
, p. 433 - 437 (2007/10/03)
Increased excretion of ethylated DNA bases has been reported in the urine of cigarette smokers. To study DNA ethylation in the target organs of smokers, an immunoenriched 32P-postlabeling assay for O4-ethylthymidine (O4-etT) was developed. O4-etT-3′-monophosphate (O4-etT-3′P) was synthesized, purified, and characterized by LC-MS, ESI-MS, and NMR. DNA was enzymatically digested to 2′-deoxynucleoside-3′-monophosphate followed by immunoprecipitation of O4-etT-3′P using specific monoclonal antibodies. The immunoconjugate was washed by filtration, and O4-etT-3′P was recovered by ethanol treatment. The enriched O4-etT-3′P was labeled with [γ-32P]ATP in the presence of T4-polynucleotide kinase at pH 6.8 to yield its 5′labeled monophosphate and was subsequently resolved on RP-HPLC and detected with online detection of radioactivity. Adduct recovery was > 80%, and the detection limit was approximately 500 amol. To further validate the method, O4-etT levels were determined in calf thymus DNA treated with N-ethyl-N-nitrosourea, and a dose-dependent formation of O4-etT was observed. Furthermore, O4-etT was found to be present in the cells obtained from the lower respiratory tract by sputum induction of two out of four smokers but not in three nonsmokers. O4-etT is a poorly repaired promutagenic DNA lesion; thus, it could be of potential use for biomonitoring smoking-related DNA damage. Our improved assay was found to be sufficiently sensitive and specific to detect O4-etT in surrogate cells from cigarette smoke exposed humans.
A convenient method for removal of the t-butyl group from nucleoside bis(t-butyl) phosphates under non-acidic conditions
Sekine, Mitsuo,Iimura, Shin,Nakanishi, Takeshi
, p. 395 - 398 (2007/10/02)
A new method for selective removal of the t-butyl group from 3′ - bis(t-butyl) phosphate esters of 5′-0-(4,4′-dimethoxytrityl)deoxyribo-nucleosides was developed by use of Me3SiCl and Et3N. Several unexpected properties of the t-buty
Phosphoryl tris-triazole - a new phosphorylating reagent
Kraszewski, Adam,Stawinski, Jacek
, p. 2935 - 2936 (2007/10/02)
Phosphoryl tris-triazole, a new phosphorylating reagent obtained from POCl3 and 1,2,4-triazole, was found to be very useful for the preparation of nucleoside 3′-phosphotriesters bearing various alkyl phosphate protective groups.
