title: 2-[3-(2-Thioxopyrrolidin-3-ylidene)methyll-tryptophan, a novel yellow pigment in salted radish roots.
abstract: The structure of the yellow pigment found in salted radish roots was studied. It was found that 1-(2-thioxopyrrolidin-3-yl)-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (TPCC) was unstable under neutral pH, and was easily converted into the yellow pigment. The yellow pigment was isolated and identified as 2-[3-(2-thioxopyrrolidin-3-ylidene)methyl]-tryptophan (TPMT) by IR, MS, 1H-, and 13C-NMR spectroscopy. In addition, we proved that this compound was the main yellow pigment in salted radish roots. This compound induced no mutagenicity in Salmonella typhimurium TA98 and TA100, either with or without prior activation.
authors.affiliation: Department of Health and Nutrition, Takasaki University of Health and Welfare, Japan. matsuoka@takasaki-u.ac.jp
authors.forename: Hiroki
authors.initials: H
authors.lastname: Matsuoka
authors.forename: Asaka
authors.initials: A
authors.lastname: Takahashi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Ozawa
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Yamada
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Uda
authors.forename: Shunro
authors.initials: S
authors.lastname: Kawakishi
mesh_terms: D000818:Animals; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D002853:Chromatography, Liquid; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008958:Models, Molecular; D008968:Molecular Conformation; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity; D010860:Pigments, Biological / Q000737:chemistry* / Q000302:isolation & purification; D018517:Plant Roots / Q000737:chemistry; D031224:Raphanus / Q000737:chemistry*; D051381:Rats; D012486:Salmonella typhimurium / Q000235:genetics; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013056:Spectrophotometry, Ultraviolet; D013871:Thiones / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D014364:Tryptophan / Q000031:analogs & derivatives / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity
chemical_list: C472486:2-(3-(2-thioxopyrrolidin-3-ylidene)methyl)tryptophan; D009153:Mutagens; D010860:Pigments, Biological; D013871:Thiones; D014364:Tryptophan; D002482:Cellulose; C068231:trisphenylcarbamoylcellulose