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-β-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.
Occurrence of Stereoisomers of 1-(2′-Pyrrolidinethione-3′-yl)-1,2,3,4- tetrahydro-β-carboline-3-carboxylic Acid in Fermented Radish Roots and Their Different Mutagenic Properties
Stereoisomers of the tetrahydro-β-carboline derivative, 1-(2′-pyrrolidinethione-3′-yl)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (PTCC), were formed from L-tryptophan with 4-methylthio-3-butenyl isothiocyanate, and their mutagenic properties and contents in different types of the radish products were studied. The isomers were identified as (1S*, 3S*, 3′R*)- and (1R*, 3S*, 3′R*)-PTCCs; the former was found as the major compound but had no mutagenic activity, while the latter was mutagenic toward Salmonella typhimurium TA 98 in the presence of a rat microsomal fraction. Both (1S*, 3S*, 3′R*)- and (1R*, 3S*, 3′R*)-PTCC were detected in a ratio of about 4:1 in a product fermented for 8 months, but only a trace was apparent in products manufactured within a few weeks.
Ozawa, Yoshio; Uda, Yasushi; Kawakishi, Shunro, Bioscience, Biotechnology and Biochemistry, 1992, vol. 56, # 1, p. 144
作者:Ozawa, Yoshio、Uda, Yasushi、Kawakishi, Shunro
DOI:——
日期:——
Ozawa, Yoshio; Uda, Yasushi; Kawakishi, Shunro, Agricultural and Biological Chemistry, 1990, vol. 54, # 7, p. 1849 - 1851