酶促水解斯替夫苷制甜茶苷及其反应路径解析  

Enzymatic Preparation of Rubusoside from Stevioside and Its Reaction Route

作　　者：周卓愉 夏咏梅 ZHOU Zhuoyu;XIA Yongmei(School of Chemical and Materials Engineering,Jiangnan University,Wuxi 214122,China;State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学化学与材料工程学院,江苏无锡214122 [2]食品科学与技术国家重点实验室,江南大学,江苏无锡214122

出　　处：《食品与生物技术学报》2021年第5期53-59,共7页Journal of Food Science and Biotechnology

基　　金：国家自然科学基金项目(31772017,31371837);国家轻工业技术与工程一流学科计划项目(LITE2018-03)。

摘　　要：β-葡萄糖苷酶可催化水解斯替夫苷生成甜茶苷,但是斯替夫苷分子中具有3个以β-1,2键连接的葡萄糖残基;反应过程中可能产生甜茶苷、甜菊双糖苷、甜菊醇单葡萄糖酯、甜菊单糖苷和甜菊醇。该水解反应的副产物的结构解析较少,反应路径解析更少,合成通量也较低,不利于工业化。以来自Aspergillus niger的β-葡萄糖苷酶催化水解斯替夫苷高通量生成甜茶苷,并通过底物特异性分析实验、产物和副产物结构解析以及过程中各组分经时变化的分析,解析β-葡萄糖苷酶催化水解斯替夫苷的具体过程。实验结果表明,该酶对斯替夫苷具有特异性,水解主产物为甜茶苷,首次阐明副产物甜菊醇单葡萄糖酯由斯替夫苷直接水解槐糖基生成,而非甜茶苷的进一步水解产物。β-glucosidase may stimulate hydrolysis of stevioside to produce rubusoside.However,there are three β-1,2-glucose residues in stevioside molecule,which may produce rubusoside,steviolbioside,steviol glucosyl ester,steviolmonoside and steviol during the hydrolysis.To date,the structures of by-products remain unclear,and the analysis of reaction route is even more limited.The reported production throughput is not high enough for industry production.β-glucosidase from Aspergillus niger was applied to catalyze the hydrolysis of stevioside for rubusoside production in high-throughput.This reaction route was analyzed through substrate specificity test,structural characterization of products and by-products,and analysis of real-time composition.The results indicate that the enzyme is specific to stevioside.The main hydrolysis product is rubusoside,and it is demonstrated for the first time that the by-product,steviol glucosyl ester,is directly produced by hydrolyzing sophorosyl group of stevioside instead of the hydrolysate of rubusoside.

关 键 词：甜茶苷 斯替夫苷 Β-葡萄糖苷酶 酶催化路径 甜菊醇单葡萄糖酯 

分 类 号：TS201.1[轻工技术与工程—食品科学]