Budget Amount *help |
¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000)
Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2016: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
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Outline of Final Research Achievements |
Detailed mechanism of oxidative dimerization of catechins during black tea manufacturing was investigated. Dimerization of pyrogallol-type catechins affords dehydrotheasinensins stereoselectively. DFT optimization of dehydrotheasinensin C suggested that the selectivity was accounted for intramolecular π-π stacking between two A-rings in aqueous solution. On the other hand, oxidative coupling between pyrogallol-type and catechol-type catechins affords theaflavins with a benzotropolone chromophore. Plane structure of the chromophore is produced via a bicyclo[3.2.1]octane-type intermediate, and formation of the intermediate was non-stereoselective coupling between catechol quinone and pyrogallol.
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