Chemical studies of oolong tea polyphenol and molecular mechanism of its bioactivity

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07427
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Food science
• Research Institution: Gifu University
• Principal Investigator: YANASE Emiko 岐阜大学, 応用生物科学部, 准教授 (60313912)
• Co-Investigator(Kenkyū-buntansha): 長岡 利 岐阜大学, 応用生物科学部, 教授 (50202221)
• Research Collaborator: NAGAOKA Satoshi 岐阜大学, 応用生物科学部, 教授 (50202221)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: Polymeric polyphenol / Oolong tea / Catechin / Oxidaiton / Oolomgtheanin

Outline of Final Research Achievements

We thought the dimeric catechin is one of the important intermediates of polymeric polyphenol generation from catechin, and to clarify the chemical structure of polymeric polyphenol, the oxidation of oolongtheanin were investigated. New intramolecular bond was formed by the oxidation of oolongtheanin, no polymerization reaction was caused. Oxidation of oolongtheanin was performed with coexistence of catechin. However, because reactivity of catechin is higher than oolongtheanin under oxidative condition, oxidation products from catechin were only produced. These result suggests that the known dimeric catechin such as oolongtheanin were not so much key intermediate of polymeric polyphenol formation but byproduct.
In order to clarify the decreasing mechanism of the micellar solubility of cholesterol, we investigated the interaction between tea polyphenols and cholesterol micelles. The data indicated a regiospecifically interaction of EGCg with taurocholic acid.

Free Research Field

天然物化学