Regioselective syntheses of trehalose-containing trisaccharides using various glycohydrolases
摘要:
Two methods were investigated for the enzymic preparation of trehalose-containing trisaccharides. In the first, a solution of saccharides is circulated through an immobilized-glycosidase column and an activated-carbon column connected in series. In the second, two enzymes having different substrate specificities are sequentially used for condensation and subsequent specific hydrolysis. Thus, 3-O-beta-D-, 4-O-beta-D-, and 6-O-beta-D-galactopyranosyl-alpha,alpha-trehalose; 4-O-alpha-D- and 6-O-alpha-D-glucopyranosyl-alpha,alpha-trehalose; and 4-O-beta-D- and 6-O-beta-D-glucopyranosyl-alpha,alpha-trehalose were synthesized stereo- and regio-selectively.
First Direct Glycosylation of Unprotected Nonreducing Mono- and Disaccharides
作者:Andreas Steinmann、Julian Thimm、Joachim Thiem
DOI:10.1002/ejoc.200700504
日期:2007.11
glycosyl acceptors is reported by random glycosylation leading to all possible regioisomers. For such systems conventional glycosylationmethods such as Koenigs–Knorr glycosylation, Schmidt's trichloroacetimidate glycosylation and reactions employing glycosyl fluoride donors fail entirely. Starting from unprotected nonreducing saccharides, the glycosylation of β-glucosylated and β-galactosylated monosaccharides
Regioselective syntheses of trehalose-containing trisaccharides using various glycohydrolases
作者:Katsumi Ajisaka、Hiroshi Fujimoto
DOI:10.1016/0008-6215(90)84264-u
日期:1990.6
Two methods were investigated for the enzymic preparation of trehalose-containing trisaccharides. In the first, a solution of saccharides is circulated through an immobilized-glycosidase column and an activated-carbon column connected in series. In the second, two enzymes having different substrate specificities are sequentially used for condensation and subsequent specific hydrolysis. Thus, 3-O-beta-D-, 4-O-beta-D-, and 6-O-beta-D-galactopyranosyl-alpha,alpha-trehalose; 4-O-alpha-D- and 6-O-alpha-D-glucopyranosyl-alpha,alpha-trehalose; and 4-O-beta-D- and 6-O-beta-D-glucopyranosyl-alpha,alpha-trehalose were synthesized stereo- and regio-selectively.