Record Information
Version1.0
StatusDetected and Quantified
Creation Date2021-05-15 02:55:30 UTC
Update Date2022-08-31 06:32:26 UTC
Metabolite IDMMDBc0010880
Metabolite Identification
Common NameUrocanic acid
DescriptionUrocanic acid (CAS: 104-98-3) is a breakdown (deamination) product of histidine. In the liver, urocanic acid is an intermediate in the conversion of histidine to glutamic acid, whereas, in the epidermis, it accumulates and may be both a UV protectant and an immunoregulator. Urocanic acid (UA) exists as a trans isomer (t-UA, approximately 30 mg/cm2) in the uppermost layer of the skin (stratum corneum). t-UA is formed as the cells of the second layer of the skin become metabolically inactive. During this process, proteins and membranes degrade, histidine is released, and histidase (histidine ammonia lyase) catalyzes the deamination of histidine to form t-UA. t-UA accumulates in the epidermis until removal by either the monthly skin renewal cycle or sweat. Upon absorption of UV light, the naturally occurring t-UA isomerizes to its cis form, c-UA. Because DNA lesions (e.g., pyrimidine dimers) in the lower epidermis can result from UV-B absorption, initial research proposed that t-UA acted as a natural sunscreen absorbing UV-B in the stratum corneum before the damaging rays could penetrate into lower epidermal zones. Researchers have found that c-UA also suppresses contact hypersensitivity and delayed hypersensitivity, reduces the Langerhans cell count in the epidermis, prolongs skin-graft survival time, and affects natural killer cell activity. (E)-Urocanic acid is found in mushrooms. It has been isolated from Coprinus atramentarius (common ink cap) and Phallus impudicus (common stinkhorn).
Structure
Synonyms
ValueSource
(2E)-3-(1H-Imidazol-4-yl)acrylic acidChEBI
(e)-3-(1H-Imidazol-4-yl)-2-propenoic acidChEBI
(2E)-3-(1H-Imidazol-4-yl)acrylateGenerator
(e)-3-(1H-Imidazol-4-yl)-2-propenoateGenerator
UrocanateGenerator
3-(1H-Imidazol-4-yl)-2-propenoateHMDB
3-(1H-Imidazol-4-yl)-2-propenoic acidHMDB
3-(1H-Imidazol-4-yl)acrylateHMDB
3-(1H-Imidazol-4-yl)acrylic acidHMDB
3-(4-Imidazolyl)acrylateHMDB
3-(4-Imidazolyl)acrylic acidHMDB
5-ImidazoleacrylateHMDB
5-Imidazoleacrylic acidHMDB
Imidazole-4-acrylateHMDB
Imidazole-4-acrylic acidHMDB
Imidazoleacrylic acidHMDB
Acid, glyoxalinylacrylicHMDB
Acid, urocanicHMDB
Glyoxalinylacrylic acidHMDB
(2E)-3-(1H-Imidazol-5-yl)-2-propenoic acidHMDB
(e)-3-(4-Imidazolyl)acrylic acidHMDB
(e)-3-(Imidazol-4-yl)-2-propenoic acidHMDB
(e)-Urocanic acidHMDB
trans-Urocanic acidHMDB
Molecular FormulaC6H6N2O2
Average Mass138.124
Monoisotopic Mass138.042927446
IUPAC Name(2E)-3-(1H-imidazol-4-yl)prop-2-enoic acid
Traditional Nametrans-urocanic acid
CAS Registry NumberNot Available
SMILES
OC(=O)\C=C\C1=CNC=N1
InChI Identifier
InChI=1S/C6H6N2O2/c9-6(10)2-1-5-3-7-4-8-5/h1-4H,(H,7,8)(H,9,10)/b2-1+
InChI KeyLOIYMIARKYCTBW-OWOJBTEDSA-N