Glutamyl Oligopeptides as Factors Responsible for Tastes of a Proteinase-modified Soybean Protein |
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Authors: | Soichi Arai Michiko Yamashita Masao Fujimaki |
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Institution: | Department of Agricultural Chemistry, University of Tokyo, Tokyo |
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Abstract: | AK-toxin I, a host-specific toxin to Japanese pear (Pyrus serotina), was synthesized as its methyl ester from three precursor fragments: conjugated diene-carboxylic acid, chiral epoxyalcohol and β-methylphenylalanine. The epoxyalcohol fragment was derived from D-fructose, in which effective homologation of the hemiacetal carbon to alkyne by using dimethyl 1-diazo-2-oxopropylphosphonate was the key reaction. The diene-carboxylic acid fragment was prepared by repeated Wittig reactions, and was combined with the epoxyalcohol fragment by the Stille reaction. Esterification of the combined product with the stereochemically-pure β-methylphenylalanine fragment afforded the target compound. This method was used to prepare the methyl ester of tritium-labeled AK-toxin I with a specific radioactivity of 213 GBq/mmol. |
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Keywords: | AK-toxin host-specific toxin Japanese pear homologation to alkyne tritium-labeling |
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