New Methods for Architectures of Glyco-materials

Abstract

This article describes new methods for architectures of glyco-materials with well-defined structures. Novel enzymatic glycosylations by using glycosyl fluorides and sugar oxazolines as glycosyl donors catalyzed by glycosyl hydrolases such as cellulase and chitinase were disclosed. The glycosylation reactions were applied to a selective elongation of a monosaccharide unit by utilizing two enzymatic processes. The first step is a hydrolase-catalyzed lactosylation or lactosaminylation toward appropriate glycosyl acceptors, giving oligosaccharides having a D-galactose unit at the non-reducing end. The second step involves β-galactosidase-catalyzed cleavage of the terminal D-galactose unit to produce the desired oligosaccharides. A facile method for synthesis of sugar oxazoline promoted by potassium fluoride will also be mentioned. A new method for construction of higher-ordered structures of polysaccharide complexes during polymerization process was developed.