alpha-Glucosidase inhibitory profile of catechins and theaflavins.
alpha-Glucosidase inhibitory profile of catechins and theaflavins.
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DOI：
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发表时间：
2007
影响因子：
6.1
通讯作者：
T. Matsui;Takashi Tanaka;S. Tamura;A. Toshima;K. Tamaya;Y. Miyata;Kazunari Tanaka;Kiyoshi Matsumoto
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文献类型：
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作者：
T. Matsui;Takashi Tanaka;S. Tamura;A. Toshima;K. Tamaya;Y. Miyata;Kazunari Tanaka;Kiyoshi Matsumoto
To clarify the postprandial glucose suppression effect of flavonoids, the inhibitory effects of catechins and theaflavins against alpha-glucosidase (AGH) were examined in this study. It was initially demonstrated that theaflavins and catechins preferentially inhibited maltase rather than sucrase in an immobilized AGH inhibitory assay system. For the maltase inhibitory effects of theaflavins, the effects were observed in descending order of potency of theaflavin (TF)-3-O-gallate (Gal) > TF-3,3'-di-O-Gal > TF-3'-O-Gal > TF. This suggests that the AGH inhibition induced by theaflavins is closely associated with the presence of a free hydroxyl group at the 3'-position of TF as well as the esterification of TF with a mono-Gal group. In addition, the R-configuration at the 3'-position of TF-3-O-Gal showed a higher inhibitory activity than the S-configuration. As a result of a single oral administration of maltose (2 g/kg) in rats, a significant reduction in blood glucose level was observed at a dose of 10 mg/kg of TF-3-O-Gal, demonstrating for the first time that TF-3-O-Gal can suppress glucose production from maltose through inhibition of AGH in the gut.
