Pterin

Pterin

Names
IUPAC names 2-Aminopteridin-4(3H)-one (one of many tautomers; see text)
Other names Pteridoxamine Pterine 4-Oxopterin 2-Amino-4-pteridone 2-Amino-4-hydroxypteridine 2-Amino-4-oxopteridine 2-aminopteridin-4-ol 2-Amino-4-pteridinol
Identifiers
CAS Number	2236-60-4 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:44992 Y
ChEMBL	ChEMBL278009 Y
ChemSpider	65806 Y
ECHA InfoCard	100.017.091
PubChem CID	73000
UNII	85MA24E1NH Y
CompTox Dashboard (EPA)	DTXSID40176894
InChI InChI=1S/C6H5N5O/c7-6-10-4-3(5(12)11-6)8-1-2-9-4/h1-2H,(H3,7,9,10,11,12) Y Key: HNXQXTQTPAJEJL-UHFFFAOYSA-N Y InChI=1/C6H5N5O/c7-6-10-4-3(5(12)11-6)8-1-2-9-4/h1-2H,(H3,7,9,10,11,12) Key: HNXQXTQTPAJEJL-UHFFFAOYAD
SMILES O=C2\N=C(/Nc1nccnc12)N
Properties
Chemical formula	C6H5N5O
Molar mass	163.137
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Pterin is a heterocyclic compound composed of a pteridine ring system, with a "keto group" (a lactam) and an amino group on positions 4 and 2 respectively. It is structurally related to the parent bicyclic heterocycle called pteridine. Pterins, as a group, are compounds related to pterin with additional substituents. Pterin itself is of no biological significance.

Pterins were first discovered in the pigments of butterfly wings^[1] (hence the origin of their name, from the Greek pteron (πτερόν),^[2] wing) and perform many roles in coloration in the biological world.