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| Names | |
|---|---|
| IUPAC name Thymidine | |
| Systematic IUPAC name 1-[(2R,4S,5R)-4-Hydroxy-5-(hydroxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4(1H,3H)-dione | |
| Other names Deoxythymidine, Td, dT, 1-[(2R,4S,5R)-4-Hydroxy-5-(hydroxymethyl)tetrahydrofur-2-yl]-5-methyl-1,3-dihydropyrimidine-2,4-dione | |
| Identifiers | |
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3D model (JSmol) | |
| ChEMBL | |
| ChemSpider |
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| DrugBank |
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| ECHA InfoCard | 100.000.065 |
| MeSH | Deoxythymidine |
| UNII | |
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| Properties | |
| C10H14N2O5 | |
| Molar mass | 242.231 g·mol−1 |
| Melting point | 185 °C |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Thymidine (symboldT ordThd), also known asdeoxythymidine,deoxyribosylthymine, orthymine deoxyriboside, is apyrimidinedeoxynucleoside. Deoxythymidine is theDNAnucleoside T, which pairs withdeoxyadenosine (A) in double-stranded DNA. In cell biology it is used tosynchronize the cells in G1/early S phase. The prefixdeoxy- is often left out since there are no precursors of thymine nucleotides involved in RNA synthesis.
Before the boom in thymidine use caused by the need for thymidine in the production of theantiretroviral drugazidothymidine (AZT), much of the world's thymidine production came fromherring sperm.[1] Thymidine occurs almost exclusively in DNA but it also occurs in theT-loop oftRNA.
In its composition, deoxythymidine is anucleoside composed ofdeoxyribose (a pentosesugar) joined to thepyrimidine basethymine.
Deoxythymidine can be phosphorylated with one, two or three phosphoric acid groups, creatingdTMP (deoxythymidinemonophosphate),dTDP, ordTTP (for thedi- andtri- phosphates, respectively).
It exists insolid form as small whitecrystals or white crystallinepowder. It has amolecular weight of242.229 Da and amelting point of 185 °C. The stability of deoxythymidine understandard temperature and pressure (STP) is very high.
Deoxythymidine is non-toxic and is part of one of the four nucleosides in DNA. It is a naturally occurring compound that exists in all living organisms and DNA viruses. Instead of thymidine, RNA containsuridine (uracil joined toribose). Uracil is chemically very similar to thymine, which is also known as 5-methyluracil. Since thymine nucleotides are precursors of DNA (but not RNA), the prefix "deoxy" is often left out, i.e., deoxythymidine is often just called thymidine.
Thymidine is listed as a chemicalteratogen.[2]
Iododeoxyuridine is a radiosensitizer and increases the amount of DNA damage received from ionizing radiation.
Azidothymidine (AZT) – used in the treatment ofHIV infection. AZTinhibits the process of reverse transcription, a critical step in theviral life cycle.
Radiolabeled thymidine (TdR), such astritiated thymidine (3H-TdR), is commonly used in cell proliferation assays. The thymidine is incorporated into dividing cells and the level of this incorporation, measured using aliquid scintillation counter, is proportional to the amount of cell proliferation. For example,lymphocyte proliferation can be measured this way inlymphoproliferative disorders.
Bromodeoxyuridine (BrdU) is another thymidine analog that is often used for the detection of proliferating cells in living tissues.
5-Ethynyl-2´-deoxyuridine (EdU) is a thymidine analog which is incorporated into the DNA of dividing cells and is used to assay DNA synthesis in cell culture or living tissues. It can be visualized by covalently binding a fluorescent azide usingclick chemistry, which is less harsh than the conditions used to expose theepitope for BrdU antibodies.
Edoxudine is anantiviral drug.
Telbivudine (β-L-2′-deoxythymidine, LdT) is the unmodified "unnatural"L-enantiomer of thymidine that was used in the treatment of chronichepatitis B.[3]
During growth ofbacteriophage T4, an excess of thymidine availability increasesmutation.[4][5] A deficiency of thymidine during growth also increases mutation.[4] A thymidylate auxotroph of the diploid yeastSaccharomyces cerevisiae was grown under conditions in which thymidyate levels varied from excess to depletion.[6] High levels of thymidylate were observed to be mutagenic and recombinogenic, whereas starvation for thymidylate was recombinogenic but only slightly mutagenic.
