没食子酸及其衍生物对α-淀粉酶作用机制研究  

The mechanism of gallic acid and its derivatives on α-amylase

作　　者：丁阳平[1,2] 张曦[1] 周洁[1] 刘辉[1] 杨坚[1] 

机构地区：[1]西南大学食品学院茶学系,重庆400716 [2]西南大学药学院,重庆400716

出　　处：《食品工业科技》2012年第2期167-169,共3页Science and Technology of Food Industry

基　　金：重庆市自然科学基金(CSTC;2010BB1134);西南大学基本科研业务费专项资金项目(XDJK2010C075)

摘　　要：实验采用碘-淀粉比色法研究没食子酸及其衍生物对α-淀粉酶的影响,结果显示:没食子酸和焦性没食子酸对α-淀粉酶具有明显的促进作用,而没食子酸酚羟基被甲基化后对α-淀粉酶的作用消失,说明酚羟基起到关键作用。当把没食子酸换成水杨酸后,对α-淀粉酶的作用由原来的促进变为抑制,说明没食子酸的三个酚羟基是缺一不可的。在探讨作用机制时发现,没食子酸的三个酚羟基可能是与α-淀粉酶三个催化所必需的酸性氨基酸残基形成稳定氢键、从而起到促进作用,而只有一个羟基的水杨酸与α-淀粉酶形成单键,可以旋转,不利于稳定α-淀粉酶的构象,从而起到抑制作用。根据本实验结果及大量文献资料可以得出以下结论:绝大多数具有酚羟基的化合物都能影响α-淀粉酶的活性,并且其作用机制都可能是通过与α-淀粉酶催化所必需的三个酸性氨基酸残基相结合来实现,其中只有一个酚羟基类的化合物可能只起到抑制作用。Idodine-starch colorimetry was carried out to determine the effect of gallic acid and its derivatives on α-amylase. The result showed that gallic acid and pyrogallic acid could increase α-amylase activity, but 3,4,5- tris（methyl）-gallic acid had no effect on α-amylase.Pyrogallic acid had a stronger effect on α-amylase activity than gallic acid.It indicated phenolic hydroxyl of gallic acid played a key role,while carboxyl group of gallic acid had negative correlation with the effect on α-amylase activity growth.The α-amylase activity was greatly inhibited when gallic acid was replaced by salicylic acid.It included that the three phenolic hydroxyl group of gallic acid was indispensable.In the further study of the mechanism of gallic acid on α-amylase,we found that the three phenolic hydroxyl group of gallic acid played a role by combination one-one correspondence with three catalytic essential amino acids of α-amylase.Salicylic acid could inhibit α-amylase activity just because the carbon-oxygen single bond of combination of α-amylase and one phenolic hydroxyl group of salicylic acid could rotate freely.Basing on the results and a lot of references,the conclusion came to that most phenolic compounds could affect activities of a-amylase.They shared the same mechanism with gallic acid.Compounds with one phenolic hydroxyl group were likely not promotion but inhibition to α-amylase.

关 键 词：Α-淀粉酶 没食子酸 作用机制 

分 类 号：TS201.2[轻工技术与工程—食品科学]