Structural investigations on bael exudate gum

Abstract

Purified, exudate gum from the bael ( Aegle marmelos) tree contains d-galactose, l-rhamnose, l-arabinose, and d-glucuronic acid in the molar ratios of ∼9:3:1:3. Degraded gum was prepared by autohydrolysis in its aqueous solution at 100°. Methylation analyses were conducted on the degraded gum, the whole gum, and the carboxyl-reduced, whole gum, and the results were corroborated by those from periodate oxidation followed by Smith degradation. The anomeric configurations of the different sugar residues in the whole-gum polysaccharide were determined by chromium trioxide oxidation of the acetylated polysaccharide. Finally, the oligo-saccharides obtained by autohydrolysis of the whole gum, and by graded hydrolysis of the degraded gum, were characterized. From these results, a tentative structure was assigned to the average repeating-unit in the polysaccharide.