1-Methylcytosine

1-Methylcytosine
Names
	Preferred IUPAC name 4-Amino-1-methylpyrimidin-2(1H)-one
Identifiers
CAS Number	1122-47-0 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:39624 ;
ChEMBL	ChEMBL500883;
ChemSpider	71474 ;
MeSH	1-Methylcytosine
PubChem CID	79143;
UNII	1J54NE82RV ;
CompTox Dashboard (EPA)	DTXSID60149949 ;
	InChI InChI=1S/C5H7N3O/c1-8-3-2-4(6)7-5(8)9/h2-3H,1H3,(H2,6,7,9) Key: HWPZZUQOWRWFDB-UHFFFAOYSA-N ; InChI=1S/C5H7N3O/c1-8-3-2-4(6)7-5(8)9/h2-3H,1H3,(H2,6,7,9) Key: HWPZZUQOWRWFDB-UHFFFAOYSA-N;
	SMILES CN1C=CC(=NC1=O)N;
Properties
Chemical formula	C5H7N3O
Molar mass	125.131 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

1-Methylcytosine is a methylated form of the DNA base cytosine.

In 1-methylcytosine, a methyl group is attached to the 1st atom in the 6-atom ring. This methyl group distinguishes 1-methylcytosine from cytosine.

History

Miriam Rossi worked on the refinement of 1-methylcytosine.^[1]

1-Methylcytosine is used as a nucleobase of hachimoji DNA, in which it pairs with isoguanine.^[2]

^ Kistenmacher, T. J.; Rossi, M. (1977-12-15). "1-Methylcytosine: a refinement". Acta Crystallographica Section B. 33 (12): 3962–3965. doi:10.1107/S0567740877012618. ISSN 0567-7408.
^ Hoshika, Shuichi; et al. (22 February 2019). "Hachimoji DNA and RNA: A genetic system with eight building blocks". Science. 363 (6429): 884–887. doi:10.1126/science.aat0971. PMC 6413494. PMID 30792304.