The nomenclature of pyrimidines is straightforward. However, like other heterocyclics, tautomeric hydroxyl groups yield complications since they exist primarily in the cyclic amide form. 554-01-8, formula is C5H7N3O, Name is 4-Amino-5-methylpyrimidin-2(1H)-one. For example, 2-hydroxypyrimidine is more properly named 2-pyrimidone. A partial list of trivial names of various pyrimidines exists. Reference of 554-01-8.
Beierlein, Frank;Volkenandt, Senta;Imhof, Petra research published 《 Oxidation Enhances Binding of Extrahelical 5-Methyl-Cytosines by Thymine DNA Glycosylase》, the research content is summarized as follows. The DNA repair protein Thymine DNA Glycosylase (TDG) removes mispaired or damaged bases, such as oxidized methyl-cytosine, from DNA by cleavage of the glycosidic bond between the sugar and the target base flipped into the enzyme’s active site. The enzyme is active against formyl-cytosine and carboxyl-cytosine, whereas the lower oxidized hydroxymethyl-cytosine and methyl-cytosine itself are not processed by the enzyme. Mol. dynamics simulations with thermodn. integration of TDG complexed to DNA carrying one of four different (oxidized) methyl-cytosine bases, methyl-cytosine (mC), hydroxymethyl-cytosine (hmC), formyl-cytosine (fC), or carboxyl-cytosine (caC) in extra-helical conformation, show a more favorable binding affinity of the higher oxidized forms, fC and caC, than the nonsubstrate bases hmC and mC. Despite rather comparable, reaction-competent conformations of the flipped bases in the active site of the enzyme, more and stronger interactions with active site residues account for the preferred binding of the higher oxidized bases. Binding of the neg. charged caC and the neutral fC are strengthened by interactions with pos. charged His151. The authors’ calculated proton affinities find this protonation state of His151 the preferred one in the presence of caC and conceivable in the presence of fC as well as increasing the binding affinity toward the two bases. Discrimination of the substrate bases is further achieved by the backbone of Tyr152 that forms a strong hydrogen bond to the carboxyl or formyl oxygen atoms of fC and caC, resp., a contact that is completely lacking in mC and much weaker in hmC. Overall, the authors’ computational results indicate that the enzyme discriminates the different oxidation forms of methyl-cytosine already at the formation of the extra-helical complexes.
Reference of 554-01-8, 5-Methylcytosine is a methylated form of the nucleobase cytosine occurring predominantly in cytosine-phosphate-guanine (CpG) islands that are produced by DNA methyltransferases and may regulate gene expression. Like cytosine, the DNA sequence containing 5-methylcytosine (5-mC) is able to be replicated without error and 5-mC can pair with guanine in double stranded DNA. However, DNA sequences containing a high local concentration of 5-mC may be less transcriptionally active than areas with higher ratios of unmodified cytosine.
5-Methylcytosine belongs to the class of organic compounds known as hydroxypyrimidines. These are organic compounds containing a hydroxyl group attached to a pyrimidine ring. Pyrimidine is a 6-membered ring consisting of four carbon atoms and two nitrogen centers at the 1- and 3- ring positions. 5-Methylcytosine exists as a solid, slightly soluble (in water), and a very weakly acidic compound (based on its pKa). Within the cell, 5-methylcytosine is primarily located in the cytoplasm. 5-Methylcytosine can be biosynthesized from cytosine. Outside of the human body, 5-methylcytosine can be found in tea. This makes 5-methylcytosine a potential biomarker for the consumption of this food product.
5-methylcytosine is a pyrimidine that is a derivative of cytosine, having a methyl group at the 5-position. It has a role as a human metabolite. It is a member of pyrimidines and a methylcytosine. It derives from a cytosine.
5-Methylcytosine is a nucleic acid that is found in the DNA and RNA of the cell. It is an important component of methylation, which is the process by which a methyl group is added to a molecule. This process can lead to cellular transformation, a process that can cause cancer. 5-Methylcytosine has also been shown as a molecular pathogenesis factor in infectious diseases such as HIV and herpes simplex virus type 1. The presence of 5-methylcytosine in nuclear DNA has been detected by analytical techniques such as gas chromatography/mass spectrometry (GC/MS). There are many analytical methods, including GC/MS, that can be used to detect 5-methylcytosine in cellular nuclei., 554-01-8.
Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia