THE CHEMICAL-STRUCTURE OF THE POLYSACCHARIDE FROM DASYCLONIUM-INCISUM

The polysaccharide from Dasyclonium incisum was found to be an agar-ty pe polymer, in which the 2-hydroxyl group on the 3,6-anhydrogalactosyl unit is partially substituted by a methyl ether, and the 4-hydroxyl g roup on the galactosyl unit is almost completely replaced by a sulphat e ester group. Minor levels of other substitution patterns were also d etected, including single branching xylose residues. Techniques used i n determining the structure include selective hydrolysis, reductive hy drolysis followed by saccharide composition and methylation analysis, infrared and C-13-NMR spectroscopy.