ABSTRACT
Many natural polysaccharides and oligosaccharides participate in a variety of biochemical reactions in vivo. Ring-opening polymerization of anhydrosugar derivatives is one of the most excellent methods for the synthesis of stereoregular polysaccharides with high molecular weights. The most well-chosen approach to the synthesis of branched polysaccharide must be polymerization of the anhydrodisaccharide derivative. This method gives a polysaccharide having one branching sugar unit per each monosaccharide residue in the main chain. Glucosamine residues in oligosaccharide or polysaccharide play important roles in vivo. Sulfation of natural polysaccharide such as dextran has been investigated in detail, chemical structures of sulfated polysaccharides prepared from synthetic polysaccharides are easier to analyze and may show simpler structure-function relationships. Polysaccharide shows some biological functions, not because it is a poly(glycoside), but because it is a polymer containing carbohydrates. It is also interesting to synthesize polymer-supported carbohydrate as a simple model of glycoconjugates.
