Urocanic acid

Structural formula
	trans isomer [( E ) isomer]
General
Surname	Urocanic acid
other names	3- (1 H -imidazol-4-yl) acrylic acid; 3- (1 H -imidazol-4-yl) prop-2-enoic acid ( IUPAC ); Urocanic acid; Urocanic acid;
Molecular formula	C 6 H 6 N 2 O 2
Brief description	white solid
External identifiers / databases
EC number	203-258-4
ECHA InfoCard	100.002.963
PubChem	1178
Wikidata	Q30536
properties
Molar mass	138.12 g mol −1
Physical state	firmly
Melting point	226–228 ° C ( trans form)
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
Toxicological data	100 mg kg −1 ( LD 50 , mouse , iv )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

The urocanic acid is an organic chemical compound and contained in human sweat as photoprotective (UV absorbing) substance. It plays an important role in protecting the skin from UVB radiation and is a histidine breakdown product (by histidase ).

It first appears in the skin as trans-urocanic acid and is partially converted into cis -urocanic acid when exposed to UVB light . The name "urocanic acid" was proposed in 1875 by Max Jaffé , who was able to detect this substance in the urine of dogs.

literature

Gertrud Pascher: Cis and trans urocanic acid as components of the stratum corneum . In: Archives for Clinical and Experimental Dermatology . tape 214 , no. 3 , 1962, pp. 234-239 , doi : 10.1007 / bf00482522 .
Beatrice Schütz: Influence of photoprotective parameters through regular visits to the solarium with special consideration of the behavior of urocanic acid. Dissertation . Technical University of Munich, 2003.
Caroline Stremnitzer: The Roles of Urocanic Acid in the Response of Epidermal Cells to UVB. Thesis . University of Vienna, 2010.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f Data sheet 4-Imidazoleacrylic acid, 99% from Sigma-Aldrich , accessed on March 10, 2014 ( PDF ).
↑ Gesundheit.de: Medical Lexicon - Urocanic Acid
^ T. Schwarz: Mechanisms of UV-induced immunosuppression. In: Keio J Med. 54 (4), 2005, pp. 165-171.
^ M. Egawa, J. Nomura, H. Iwaki: The evaluation of the amount of cis- and trans-urocanic acid in the stratum corneum by Raman spectroscopy. In: Photochem. Photobiol. Sci. 9, 2010, pp. 730-733.
↑ S. Edlbacher, Ms Heitz: To knowledge of urocanic acid. In: Hoppe-Seyler's magazine for physiological chemistry. Volume 279, Issue 1–2, October 2009, pp. 63–65, ISSN 0018-4888 , doi: 10.1515 / bchm2.1943.279.1-2.63 .
↑ M. Jaffe: Ueber die Urocaninsäure . In: Reports of the German Chemical Society . tape 8 , no. 1 , January 1875, p. 811-813 , doi : 10.1002 / cber.187500801267 ( PDF ).
↑ M. Jaffe: About a new component of dog's urine . In: Reports of the German Chemical Society . tape 7 , no. 2 , July 1874, p. 1669–1673 , doi : 10.1002 / cber.187400702225 .

[Sigma-1] ↑ ^a ^b ^c ^d ^e ^f Data sheet 4-Imidazoleacrylic acid, 99% from Sigma-Aldrich , accessed on March 10, 2014 ( PDF ).

[gesundheit-2] Gesundheit.de: Medical Lexicon - Urocanic Acid

[3] T. Schwarz: Mechanisms of UV-induced immunosuppression. In: Keio J Med. 54 (4), 2005, pp. 165-171.

[4] M. Egawa, J. Nomura, H. Iwaki: The evaluation of the amount of cis- and trans-urocanic acid in the stratum corneum by Raman spectroscopy. In: Photochem. Photobiol. Sci. 9, 2010, pp. 730-733.

[5] S. Edlbacher, Ms Heitz: To knowledge of urocanic acid. In: Hoppe-Seyler's magazine for physiological chemistry. Volume 279, Issue 1–2, October 2009, pp. 63–65, ISSN 0018-4888 , doi: 10.1515 / bchm2.1943.279.1-2.63 .

[6] M. Jaffe: Ueber die Urocaninsäure . In: Reports of the German Chemical Society . tape 8 , no. 1 , January 1875, p. 811-813 , doi : 10.1002 / cber.187500801267 ( PDF ).

[7] M. Jaffe: About a new component of dog's urine . In: Reports of the German Chemical Society . tape 7 , no. 2 , July 1874, p. 1669–1673 , doi : 10.1002 / cber.187400702225 .