α-glucosidase inhibitory profile of catechins and theaflavins
α-glucosidase inhibitory profile of catechins and theaflavins
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DOI：
10.1021/jf0627672
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发表时间：
2007-01-10
影响因子：
6.1
通讯作者：
Matsumoto, Kiyoshi
中科院分区：
文献类型：
--
作者：
Matsui, Toshiro;Tanaka, Takashi;Matsumoto, Kiyoshi
为了阐明黄酮类化合物的餐后血糖抑制作用，本研究检测了儿茶素和茶黄素对α-葡萄糖苷酶（AGH）的抑制作用。初步证明，茶黄素和儿茶素优先抑制麦芽糖酶，而不是蔗糖酶在固定化AGH抑制测定系统。对于茶黄素的麦芽糖酶抑制作用，观察到的效果从大到小的顺序为茶黄素（TF）-3-O-没食子酸酯（Gal）> TF-3，3 '-di-O-Gal > TF-3'-O-Gal > TF。这表明茶黄素诱导的AGH抑制与TF的3 '-位上存在游离羟基以及TF与单-Gal基团的酯化密切相关。此外，TF-3-O-Gal的3 '-位的R-构型比S-构型显示出更高的抑制活性。作为在大鼠中单次口服给予麦芽糖（2g/kg）的结果，在10 mg/kg剂量的TF-3-O-Gal下观察到血糖水平的显著降低，首次证明TF-3-O-Gal可以通过抑制肠道中的AGH来抑制麦芽糖的葡萄糖产生。
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.