Kojic acid

Structural formula
General
Surname	Kojic acid
other names	5-hydroxy-2- (hydroxymethyl) -4-pyrone; KOJIC ACID ( INCI ) ;
Molecular formula	C 6 H 6 O 4
Brief description	Colorless prismatic crystal needles
External identifiers / databases
EC number	207-922-4
ECHA InfoCard	100.007.203
PubChem	3840
ChemSpider	3708
DrugBank	DB01759
Wikidata	Q416285
properties
Molar mass	142.11 g mol −1
Physical state	firmly
Melting point	153-154 ° C
pK s value	7.90 (8.03)
solubility	soluble in water and ethanol ; soluble in acetone , methanol and DMSO ; slightly soluble in ethyl acetate , chloroform , pyridine and diethyl ether ; practically insoluble in benzene ;
safety instructions
GHS labeling of hazardous substances danger
H and P phrases	H: 351
	P: 201-281
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Kojic acid occurs naturally in the mycelia of various fungi , especially in the Aspergillus oryzae mold . It was isolated for the first time in 1907.

Extraction

Kojic acid is produced by fermenting glucose-containing solutions with Aspergillus species, mainly from the Aspergillus flavus / Aspergillus oryzae group .

properties

With some heavy metal ions (Fe ³⁺ , Cu ²⁺ , Zn ²⁺ ), kojic acid forms colored, sparingly soluble chelate complexes .

effect

Kojic acid has anti-inflammatory and antibacterial properties. However, it is mainly used because of its effect as a tyrosinase inhibitor . When applied to the skin, this property inhibits the formation of melanin and thus bleaches the skin. This effect is particularly popular in Asia, which is why there are many cosmetics with kojic acid on the market there. The use of kojic acid in cosmetic products is not regulated in the European Union; it is prohibited in Switzerland.

Individual evidence

↑ Entry on KOJIC ACID in the CosIng database of the EU Commission, accessed on July 1, 2020.
↑ ^a ^b ^c Entry on kojic acid. In: Römpp Online . Georg Thieme Verlag, accessed on December 29, 2014.
↑ Hermann Ammon (Ed.): Hunnius Pharmaceutical Dictionary . 8th edition, de Gruyter, Berlin 2004. ISBN 3-11-015792-6 .
↑ ^a ^b ^c ^d ^e data sheet Kojic acid, 99% from AlfaAesar, accessed on December 21, 2019 ( PDF )(JavaScript required) .

[CosIng-1] Entry on KOJIC ACID in the CosIng database of the EU Commission, accessed on July 1, 2020.

[Römpp-2] Entry on kojic acid. In: Römpp Online . Georg Thieme Verlag, accessed on December 29, 2014.

[Hunnius-3] Hermann Ammon (Ed.): Hunnius Pharmaceutical Dictionary . 8th edition, de Gruyter, Berlin 2004. ISBN 3-11-015792-6 .

[Alfa-4] ↑ ^a ^b ^c ^d ^e data sheet Kojic acid, 99% from AlfaAesar, accessed on December 21, 2019 ( PDF )(JavaScript required) .