title: Isolation of S-[2-carboxy-1-(1H-imidazol-4-yl)ethyl]cysteine from human urine.
abstract: S-[2-Carboxy-1-(1H-imidazol-4-yl)ethyl]cysteine (I), a proposed precursor of 3-[(carboxymethyl)thio]-3-(1H-imidazol-4-yl)propanoic acid [Kinuta, Yao, Masuoka, Ohta, Teraoka & Ubuka (1991) Biochem. J. 275, 617-721], was isolated from healthy human urine by using ion-exchange column chromatography. Identification of the isolated compound with compound (I) was performed by physicochemical analyses involving i.r., m.s. and n.m.r. spectrometries as well as high-voltage paper electrophoresis, t.l.c. and paper chromatography. Compound (I) was synthesized in 80% yield by incubation of a reaction mixture containing trans-urocanic acid and 3-fold excess of cysteine at 70-75 degrees C. From these results we suggest that natural thiol compounds such as cysteine and GSH participate in the metabolism of urocanic acid, a key metabolite of L-histidine.
authors.affiliation: Department of Biochemistry, Okayama University Medical School, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kinuta
authors.forename: T
authors.initials: T
authors.lastname: Ubuka
authors.forename: K
authors.initials: K
authors.lastname: Yao
authors.forename: S
authors.initials: S
authors.lastname: Futani
authors.forename: M
authors.initials: M
authors.lastname: Fujiwara
authors.forename: Y
authors.initials: Y
authors.lastname: Kurozumi
mesh_terms: D002852:Chromatography, Ion Exchange; D003545:Cysteine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism / Q000652:urine; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D007093:Imidazoles / Q000138:chemical synthesis / Q000378:metabolism / Q000652:urine*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014560:Urocanic Acid / Q000378:metabolism
chemical_list: D007093:Imidazoles; C069009:3-((carboxymethyl)thio)-3-(1H-imidazol-4-yl)propanoic acid; C069010:S-(2-carboxy-1-(1H-imidazol-4-yl) ethyl)cysteine; D014560:Urocanic Acid; D005978:Glutathione; D003545:Cysteine