trans-Urocanic Acid

trans-Urocanic acid is a major epidermal chromophore for the immunosuppressive effects of UV radiation that is produced in mammalian stratum corneum by the action of histidine ammonialyase on L-histidine. It contributes to the acidification of the surface of the stratum corneum, and its function has been proposed as that of an endogenous sunscreen, endowing a low-level of protection (SPF ~ 1.5) against UV-induced DNA damage and excessive keratinocyte apoptosis. Upon UVB exposure, trans-urocanic acid is converted to the cis isomer, which is known to activate regulatory T cells.Formal Name: 3-(1H-imidazol-5-yl)-2E-propenoic acid. CAS Number: 3465-72-3. Molecular Formula: C6H6N2O2. Formula Weight: 138.1. Purity: >98%. Formulation: (Request formulation change), A crystalline solid. Solubility: DMF: 3 mg/ml, DMSO: 15 mg/ml, PBS (pH 7.2): 0.3 mg/ml. lambdamax: 286 nm. SMILES: OC(/C=C/C1=CN=CN1)=O. InChi Code: 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 Key: LOIYMIARKYCTBW-OWOJBTEDSA-N.