Synthesis of Functional Polysaccharides and Their Derivations to Biologically Active Polymer Materials

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The purpose of this investigation is to synthesize biologically active polysaccharides by the conversion of polysaccharide derivatives which are prepared by ring-opening polymerizations of anhydro sugars obtained from natural carbohydrates.1. Synthesis of Biologically Active Polymer Materials from Ribose Polymers and Copolymers. Although a sulfated (1->5)- <alpha> -D-ribofuranan which was prepared by ring-opening polymerization of a 1,4-anhydro-ribose derivative showed a high anticoagulant activity, a non-stereoregular polymer with a mixed structure consisting of (1->5)- <alpha> -D-ribofuranosidic and (1->4)- <beta> -D-ribopyranosidic units was sulfated to give a heparinoid with a low activity. Next, a stereoregular copolysaccharide (1->5)- <alpha> -riboxylan which is composed of 34% ribofuranosidic and 66% xylofuranosidic units was obtained by copolymerization of the two monomers. The sulfated (1->5)- <alpha> -riboxylan showed a lower anticoagulant activity than that of the individual … More homopolymers, but it was higher than that of the non-stereoregular poly-ribose. Antigen-antibody reaction of polysaccharides was examined by reacting ribopyranan, ribofuranan containing a small fraction of ribopyranose units, and ribofuranan with an antibody made by the injection of (1->4)- <beta> -Dribopyranan. The reaction between the ribopyranan and the antibody well took place. However, no reaction between the ribofuranan and the antibody occurred. And, the reaction to a small extent occurred in the case of the ribofuranan containing a small fraction of ribopyranose units, In addition, the ability for the ribofuranan to produce an antibody was too weak to give no antibody in the rabbit.2. Synthesis of Branched Polysaccharides and Its Biological Function. A dextran with <alpha> -D-mannopyranosyl branches at C-3 position was synthesized. from polymerization of tert-butyldimethylsilylated 1,6-anhydro- <beta> -D-glucopyranose and subsequent branching reaction. The mannose-branched dextran reacted with an anti-natural-dextran to a almost equal extent to a glucose-branched. Less