Polymer-Like Polyphenols of Black Tea and Their Lipase and Amylase Inhibitory Activities
-
- Kusano Rie
- Graduate School of Biomedical Sciences, Nagasaki University
-
- Andou Hisashi
- Graduate School of Biomedical Sciences, Nagasaki University
-
- Fujieda Miho
- Graduate School of Biomedical Sciences, Nagasaki University
-
- Tanaka Takashi
- Graduate School of Biomedical Sciences, Nagasaki University
-
- Matsuo Yosuke
- Graduate School of Biomedical Sciences, Nagasaki University
-
- Kouno Isao
- Graduate School of Biomedical Sciences, Nagasaki University
Search this article
Abstract
Lipase and amylase inhibitory activities of black tea were examined. After solvent partitioning of a black tea extract with the ethyl acetate and n-butanol, the two soluble fractions showed comparable inhibitory activities. Activity in the ethyl acetate fraction was mainly attributable to polyphenols with low-molecular weights, such as theaflavin gallates. On the other hand, the active substance in the n-butanol layer was ascertained to be a polymer-like substance. 1H- and 13C-NMR spectra showed signals arising from the flavan A-ring and galloyl groups, although signals due to flavan B-rings were not detected, suggesting that the polymer-like substances were generated by oxidative condensation of flavan B-rings, a result which was previously deduced from our results of in vitro catechin oxidation experiments. Enzymatic oxidation of epicatechin 3-O-gallate produced a similar polymer-like substance and suggested that condensation between a B-ring and galloyl groups was involved in the polymerization reaction.
Journal
-
- Chemical and Pharmaceutical Bulletin
-
Chemical and Pharmaceutical Bulletin 56 (3), 266-272, 2008
The Pharmaceutical Society of Japan
- Tweet
Keywords
Details 詳細情報について
-
- CRID
- 1390282679145737856
-
- NII Article ID
- 110006622627
-
- NII Book ID
- AA00602100
-
- ISSN
- 13475223
- 00092363
-
- HANDLE
- 10069/17916
-
- NDL BIB ID
- 9394378
-
- Text Lang
- en
-
- Data Source
-
- JaLC
- IRDB
- NDL
- Crossref
- CiNii Articles
-
- Abstract License Flag
- Disallowed