Thymine

Names

IUPAC name

5-Methylpyrimidine-2,4(1H,3H)-dione

Other names

5-methyluracil

Identifiers

CAS Number

65-71-4^Y

3D model (Jmol)

CHEBI:17821^N

ChEMBL993^N

1103^N

QR26YLT7LT^Y

InChI=1S/C5H6N2O2/c1-3-2-6-5(9)7-4(3)8/h2H,1H3,(H2,6,7,8,9)^N

Key: RWQNBRDOKXIBIV-UHFFFAOYSA-N^N
InChI=1/C5H6N2O2/c1-3-2-6-5(9)7-4(3)8/h2H,1H3,(H2,6,7,8,9)

Key: RWQNBRDOKXIBIV-UHFFFAOYAL

SMILES

Cc1c[nH]c(=O)[nH]c1=O

Properties

Chemical formula

C₅H₆N₂O₂

Molar mass

126.12 g·mol⁻¹

Density

1.23 g cm⁻³ (calculated)

Melting point

316 to 317 °C (601 to 603 °F; 589 to 590 K)

Boiling point

335 °C (635 °F; 608 K) (decomposes)

Acidity (pK_a)

9.7

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

(what is ^YN ?)

Infobox references

Thymine /ˈθaɪmᵻn/ (T, Thy) is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidine nucleobase. In RNA, thymine is replaced by the nucleobase uracil. Thymine was first isolated in 1893 by Albrecht Kossel and Albert Neumann from calves' thymus glands, hence its name.

As its alternate name (5-methyluracil) suggests, thymine may be derived by methylation of uracil at the 5th carbon. In RNA, thymine is replaced with uracil in most cases. In DNA, thymine (T) binds to adenine (A) via two hydrogen bonds, thereby stabilizing the nucleic acid structures.

Thymine combined with deoxyribose creates the nucleoside deoxythymidine, which is synonymous with the term thymidine. Thymidine can be phosphorylated with up to three phosphoric acid groups, producing dTMP (deoxythymidine monophosphate), dTDP, or dTTP (for the di- and tri- phosphates, respectively).

One of the common mutations of DNA involves two adjacent thymines or cytosine, which, in presence of ultraviolet light, may form thymine dimers, causing "kinks" in the DNA molecule that inhibit normal function.

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Wikipedia