5-Methylcytosine

5-Methylcytosine
Names
	Preferred IUPAC name 4-Amino-5-methylpyrimidin-2(1H)-one
Identifiers
CAS Number	554-01-8 ;
3D model (JSmol)	Interactive image; Interactive image;
Beilstein Reference	120387
ChEBI	CHEBI:27551 ;
ChemSpider	58551 ;
ECHA InfoCard	100.008.236
EC Number	209-058-3;
KEGG	C02376 ;
MeSH	5-Methylcytosine
PubChem CID	65040;
UNII	6R795CQT4H ;
CompTox Dashboard (EPA)	DTXSID50203948 ;
	InChI InChI=1S/C5H7N3O/c1-3-2-7-5(9)8-4(3)6/h2H,1H3,(H3,6,7,8,9) Key: LRSASMSXMSNRBT-UHFFFAOYSA-N ; InChI=1/C5H7N3O/c1-3-2-7-5(9)8-4(3)6/h2H,1H3,(H3,6,7,8,9) Key: LRSASMSXMSNRBT-UHFFFAOYAO;
	SMILES O=C1/N=C\C(=C(\N)N1)C; Cc1cnc(=O)[nH]c1N;
Properties
Chemical formula	C5H7N3O
Molar mass	125.131 g·mol−1
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H317, H319
Precautionary statements	P261, P264, P272, P280, P302+P352, P305+P351+P338, P321, P333+P313, P337+P313, P363, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

5-Methylcytosine (5mC) is a methylated form of the DNA base cytosine (C) that regulates gene transcription and takes several other biological roles. When cytosine is methylated, the DNA maintains the same sequence, but the expression of methylated genes can be altered (the study of this is part of the field of epigenetics). 5-Methylcytosine is incorporated in the nucleoside 5-methylcytidine.