Ionic liquids as cosolvents for glycosylation by sucrose phosphorylase: balancing acceptor solubility and enzyme stability
作者:Karel De Winter、Kristien Verlinden、Vladimír Křen、Lenka Weignerová、Wim Soetaert、Tom Desmet
DOI:10.1039/c3gc40449h
日期:——
Over the past decade, disaccharide phosphorylases have received increasing attention as promising biocatalysts for glycoside synthesis. Unfortunately, these enzymes typically have a very low affinity for non-carbohydrate acceptors, which urges the addition of cosolvents to increase the dissolved concentration of these acceptors. However, commonly applied solvents such as methanol and dimethyl sulfoxide (DMSO) are not compatible with many intended applications of carbohydrate-derived products. In this work, the solubility of a wide range of relevant acceptors was assessed in the presence of ionic liquids (ILs) as alternative and ‘green’ solvents. The IL AMMOENG 101 was found to be the most effective cosolvent for compounds as diverse as medium- and long-chain alcohols, flavonoids, alkaloids, phenolics and terpenes. Moreover, this IL was shown to be less deleterious to the stability and activity of sucrose phosphorylase than the commonly used dimethyl sulfoxide. To demonstrate the usefulness of this solvent system, a process for the resveratrol glycosylation was established in a buffer containing 20% AMMOENG 101, 1 M sucrose and saturated amounts of the acceptor. A single regioisomer 3-O-α-D-glucopyranosyl-(E)-resveratrol was obtained as proven by NMR spectroscopy.
在过去的十年中,二糖磷酸化酶作为一种有前途的糖苷合成生物催化剂,受到了越来越多的关注。遗憾的是,这些酶对非碳水化合物受体的亲和力通常很低,因此需要添加助溶剂来增加这些受体的溶解浓度。然而,甲醇和二甲基亚砜(DMSO)等常用溶剂与碳水化合物衍生产品的许多预期应用不兼容。在这项工作中,我们评估了多种相关受体在离子液体(IL)作为替代和 "绿色 "溶剂存在时的溶解度。研究发现,离子液体 AMMOENG 101 是中长链醇、类黄酮、生物碱、酚类和萜类等多种化合物最有效的共溶剂。此外,与常用的二甲亚砜相比,这种 IL 对蔗糖磷酸化酶的稳定性和活性的影响较小。为了证明这种溶剂系统的实用性,我们在含有 20% AMMOENG 101、1 M 蔗糖和饱和量受体的缓冲液中建立了白藜芦醇糖基化过程。核磁共振光谱证明,得到了单一的 3-O-α-D-吡喃葡萄糖基-(E)-白藜芦醇异构体。
Biphasic Catalysis with Disaccharide Phosphorylases: Chemoenzymatic Synthesis of α-<scp>d</scp>-Glucosides Using Sucrose Phosphorylase
作者:Karel De Winter、Tom Desmet、Tim Devlamynck、Lisa Van Renterghem、Tom Verhaeghe、Helena Pelantová、Vladimír Křen、Wim Soetaert
DOI:10.1021/op400302b
日期:2014.6.20
this work, a buffer/ethyl acetate ratio of 5:3 was identified to be the optimal solvent system, allowing the use of SP in biphasic systems. Careful optimization of the reaction conditions enabled the synthesis of a range of α-d-glucosides, such as cinnamyl α-d-glucopyranoside, geranyl α-d-glucopyranoside, 2-O-α-d-glucopyranosyl pyrogallol, and series of alkyl gallyl 4-O-α-d-glucopyranosides. The usefulness
由于其广泛的受体特异性,蔗糖磷酸化酶(SP)已被用于将葡萄糖转移至多种受体分子。不幸的是,SP对这些受体的亲和力低(K m > 1 M)通常促使添加助溶剂,助溶剂通常不能溶解足够的底物或逐渐引起酶抑制和变性。在这项工作中,确定缓冲液/乙酸乙酯的比例为5:3是最佳溶剂系统,从而允许在双相系统中使用SP。的反应条件的仔细优化启用的范围α-的合成d -glucosides,如肉桂α- d吡喃葡萄糖苷,香叶基α- d吡喃葡萄糖苷,2- ö-α- d吡喃葡萄糖基邻苯三酚,和烷基gallyl 4-系列ö -α- d -glucopyranosides。通过在辅助溶剂和双相反应系统中比较邻苯三酚的葡萄糖基化进一步说明了双相催化的有用性。前者的受体收率仅达到17.4%,而使用双相催化时,大约60%的初始邻苯三酚会转化。