Thymidine
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219639056
2008-06-16T05:15:07Z
PlankBot
7310603
Robot-assisted disambiguation: Powder - Changed link(s) to [[Powder (substance)]]
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|ImageFile=DT chemical structure.png
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|Section1= {{Chembox Identifiers
| CASNo=50-89-5
| PubChem=1134
| SMILES=CC1=CN(C(=O)NC1=O)C2CC(C(O2)CO)O
| MeSHName=Thymidine
}}
|Section2= {{Chembox Properties
| Formula=C<sub>10</sub>H<sub>14</sub>N<sub>2</sub>O<sub>5</sub>
| MolarMass=242.229
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|Section3= {{Chembox Hazards
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'''Thymidine''' (more precisely called '''deoxythymidine'''; can also be labelled '''deoxyribosylthymine''', and '''thymine deoxyriboside''') is a [[chemical]] [[Chemical compound|compound]], more precisely a [[pyrimidine]] [[deoxynucleoside]]. Deoxythymidine is the [[DNA]] nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. In cell biology it is used to synchronize the cells in S phase.
==Structure and properties==
In its composition, deoxythymidine is [[deoxyribose]] (a pentose [[sugar]]) joined to the [[pyrimidine]] base [[thymine]].
Deoxythymidine can be phosphorylated with one, two or three phosphoric acid groups, creating respectively dTMP, dTDP or dTTP ((deoxy)thymidine mono- di- or triphosphate).
It exists in [[solid]] form as small white [[crystals]] or white crystalline [[Powder (substance)|powder]], has a [[molecular weight]] of 242.229 [[unified atomic mass unit|u]], and has a [[melting point]] of 185 [[degrees Celsius|°C]]. The stability of deoxythymidine under [[standard temperature and pressure]] (STP) is very high.
Deoxythymidine is non-toxic and as part of one of the four nucleotides in DNA it is a naturally occurring compound that exists in all living organisms and DNA viruses. RNA has uridine (uracil joined to ribose) instead. Uracil is chemically very similar to thymine, the latter being 5-methyluracil. Since thymine nucleotides are precursors of DNA, not RNA, the prefix "deoxy" is often left out, i.e., deoxythymidine is often just called thymidine.
==Modified analogs of thymidine==
[[Iododeoxyuridine]] is a radiosensitizer and increases the amount of DNA damage received from ionizing radiation.
[[Azidothymidine]] (AZT) - used in the treatment of [[HIV]] infection. AZT [[Reverse transcriptase inhibitor|inhibits the process of reverse transcription]], a critical step in the [[HIV#Replication_cycle|viral life cycle]].
[[tritium|Tritiated]] thymidine is commonly used in cell proliferation assays. The thymidine is incorporated into dividing cells and the level of this incorporation, measured using a liquid scintillation counter, is proportional to the amount of cell proliferation.
[[Bromodeoxyuridine]] (BrdU) is another thymidine analog that is often used for the detection of proliferating cells in living tissues.
==External links==
{{Nucleobases, nucleosides, and nucleotides}}
[[Category:Nucleosides]]
[[de:Thymidin]]
[[es:Timidina]]
[[fr:Désoxythymidine]]
[[it:Timidina]]
[[lt:Timidinas]]
[[ja:チミジン]]
[[pl:Tymidyna]]
[[pt:Timidina]]
[[zh:胸苷]]