Direct Synthesis of <i>para</i>-Nitrophenyl Glycosides from Reducing Sugars in Water
作者:Xin Qiu、Antony J. Fairbanks
DOI:10.1021/acs.orglett.0c00728
日期:2020.3.20
be directly converted into the corresponding para-nitrophenyl (pNP) glycosides using 2-chloro-1,3-dimethylimidazolinium chloride (DMC), para-nitrophenol, and a suitable base in aqueous solution. The reaction is stereoselective for sugars with either a hydroxyl or an acetamido group at position 2, yielding the 1,2-trans pNP glycosides. A judicious choice of base allows extension to di- and oligosaccharide
Environmentally benign glycosylation of aryl pyranosides and aryl/alkyl furanosides demonstrating the versatility of thermostable CGTase from Thermoanaerobacterium sp.
transfer reactions besides showing low hydrolytic activity. Here, the effect of the anomeric configuration of the glycosyl acceptor on the regioselectivity of CGTase catalyzed glycosylations was investigated. For this purpose, the α and β anomers of p-nitrophenyl-D-glucopyranoside were used as glycosyl acceptors, Bacillus macerans and Thermoanaerobacter sp. CGTases were used as biocatalysts and β-cyclodextrin
Verfahren zur beta-Galactosidase-katalysierten Transglycosidierung mit unphysiologischen Glycosyldonoren
申请人:HOECHST AKTIENGESELLSCHAFT
公开号:EP0551107A2
公开(公告)日:1993-07-14
Die Erfindung betrifft Verfahren zur β-Galactosidase-katalysierten Transglycosidierung, wobei als Glycosyldonoren für β-Galactosidase unphysiologische bzw. unnatürliche Glycoside eingesetzt werden.
Isolation and characterization of a novel α-glucosidase with transglycosylation activity from Arthrobacter sp. DL001
作者:Kun Zhou、Hong-wei Luan、Ying Hu、Guang-bo Ge、Xing-bao Liu、Xiao-chi Ma、Jie Hou、Xiu-li Wang、Ling Yang
DOI:10.1016/j.molcatb.2012.04.016
日期:2012.8
A strain of Arthrobacter sp. DL001 with high transglycosylation activity was successfully isolated from the Yellow Sea of China. To purify the extracellular enzyme responsible for transglycosylation, a four-step protocol was adopted and the enzyme with electrophoretical purity was obtained. The purified enzyme has a molecular mass of 210 kDa and displays a narrow hydrolysis specificity towards alpha-1,4-glucosidic bond. Its hydrolytic activity was identified as decreasing in the order of maltotriose > panose > maltose. Only 3.61% maltose activity occurs when p-nitrophenyl alpha-D-glycopyranoside serves as a substrate, suggesting that this enzyme belongs to the type II alpha-glucosidase. In addition, the enzyme was able to transfer glucosyl groups from the donors containing alpha-1,4-glucosidic bond specific to glucosides, xylosides and alkyl alcohols in alpha-1,4- or alpha-1,6-manners. A decreased order of activity was observed when maltose, maltotriose, panose, beta-cyclodextrin and soluble starch served as glycosyl donors, respectively. When maltose was utilized as a donor and a series of p-nitrophenyl-glycosides as acceptors, the glucosidase was capable of transferring glucosyl groups to p-nitrophenyl-glucosides and p-nitrophenyl-xylosides in alpha-1,4- or alpha-1,6-manners. The yields of p-nitrophenyl-oligosaccharides could reach 42-60% in 2 h. When a series of alkyl alcohols were utilized as acceptors, the enzyme exhibited its transglycosylation activities not only to the primary alcohols but also to the secondary alcohols with carbon chain length 1-4. Therefore, all the results indicated that the purified alpha-glucosidase present a useful tool for the biosynthesis of oligosaccharides and alkyl glucosides. (C) 2012 Elsevier B.V. All rights reserved.