| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2000: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1999: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Research Abstract |
Hybrid type polysaccharides are the most important components of hemicellulose in plant cell walls. The structure of these polysaccharides contains a β-1, 4 linked D-glucopyranose residue with various monosaccharides such as mannose and xylose. Xyloglucan is a heteropolysaccharide with one to three monosaccharides units linked to the main chain. It is, therefore, necessary to prepare a xyloglucans having a well-refined structure with a regular repeating unit in order to investigate its biological activities, physical and chemical properties.
The present project deals with the first synthesis of xyloglucan derivatives and glucomannan derivatives with a perfect repeating unit by the enzymatic polycondensation of glycosyl fluoride monomers.
Preparation of trisaccharide from xyloglucan from Tamarindus has been achieved by treating naturally occurring xyloglucan with β1, 4-glycanase, β-glucosidase, and isoprimeverose producing enzyme, affording O-α-D-xylopyranosyl-(1-6)-β-D-glucopyranosyl-D-glucopyranose. The anomeric hydroxy group was converted to the fluorine atom via acetylation, bromination, fluorination, and deacetylation. The polycondensation was carried out in an aqueous organic solvent, giving rise to a novel branched polysaccharides. A new disaccharide monomer (Man-Glc-F) has also been designed and prepared for the enzymatic polycondensation, aiming at the synthesis of artificial glucomannan derivatives. Based on these results, a term "Glycochemisty Cycle System" has been proposed as a new concept for production of functional polysaccharide materials from biomasses.
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