Thymine
C₅H₆N₂O₂·126.113 g/mol·Biochemical·CID 1135
NucleobaseEssential
A pyrimidine nucleobase found only in DNA (replaced by uracil in RNA). Pairs with adenine via two hydrogen bonds. UV light can cause thymine dimers — a common form of DNA damage leading to mutations.
IUPAC: 5-methyl-1H-pyrimidine-2,4-dione
Also known as: 65-71-4, 5-methyluracil, 2,4-Dihydroxy-5-methylpyrimidine, Thymin, 5-Methyl-1,2,3,4-tetrahydropyrimidine-2,4-dione (+14 more)
Molecular Structure
Molecular Propertiesmass · H-bonds · stereo
Molecular Weight
126.110g/mol
Exact Mass
126.042927Da
Monoisotopic Mass
126.042927Da
XLogP
-0.6
Polar Surface Area
58.2Ų
Complexity
195
Formal Charge
0
H-Bond Donors
2
H-Bond Acceptors
2
Rotatable Bonds
0
Heavy Atoms
9
Stereo Centers
0
Bond Stereo
0
Drug-Likeness (Lipinski's Rule of Five)
✓ 126.1 g/mol
MW ≤ 500
✓ -0.6
LogP ≤ 5
✓ 2
H-bond donors ≤ 5
✓ 2
H-bond acceptors ≤ 10
Passes all rules — good oral bioavailability predicted
GHS Hazard Classification
Warning
Hazards
H319Causes serious eye irritation
Source: PubChem GHS Classification. Always consult the SDS for handling.