Kojic acid

Kojic acid
Names
	Preferred IUPAC name 5-Hydroxy-2-(hydroxymethyl)-4H-pyran-4-one
	Other names Kojic acid, 5-Hydroxy-2-(hydroxymethyl)-4-pyrone, 2-hydroxymethyl-5-hydroxy-γ-pyrone
Identifiers
CAS Number	501-30-4 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	120895
ChEBI	CHEBI:43572 ;
ChEMBL	ChEMBL287556 ;
ChemSpider	3708 ;
DrugBank	DB01759 ;
ECHA InfoCard	100.007.203
EC Number	207-922-4;
Gmelin Reference	3620
KEGG	C14516 ;
PubChem CID	3840;
RTECS number	UQ0875000;
UNII	6K23F1TT52 ;
CompTox Dashboard (EPA)	DTXSID2040236 ;
	InChI InChI=1S/C6H6O4/c7-2-4-1-5(8)6(9)3-10-4/h1,3,7,9H,2H2 Key: BEJNERDRQOWKJM-UHFFFAOYSA-N ; InChI=1/C6H6O4/c7-2-4-1-5(8)6(9)3-10-4/h1,3,7,9H,2H2;
	SMILES O=C1/C=C(\O/C=C1/O)CO;
Properties
Chemical formula	C6H6O4
Molar mass	142.110 g·mol−1
Appearance	white
Melting point	152 to 155 °C (306 to 311 °F; 425 to 428 K)
Solubility in water	Slight
Acidity (pKa)	9.40
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H351
Precautionary statements	P201, P280, P308+P313
	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

Kojic acid is an organic compound with the formula HOCH₂C₅H₂O₂OH. It is a derivative of 4-pyrone that functions in nature as a chelation agent produced by several species of fungus, especially Aspergillus oryzae, which has the Japanese common name koji. Kojic acid is a by-product in the fermentation process of malting rice, for use in the manufacturing of sake, the Japanese rice wine. It is a mild inhibitor of the formation of pigment in plant and animal tissues, and is used in food and cosmetics to preserve or change colors of substances. It forms a bright red complex with ferric ions.