Studies of the distribution of the 4- O-methyl- d-glucuronic acid residues in birch xylan

Abstract

The distribution of the 4- O-methyl- d-glucuronic acid residues in birch xylan has been studied. Elimination of the 4- O-methyl- d-glucuronic acid residues of methylated birch-xylan was followed by specific cleavage of the xylan backbone at the originally branched d-xylose residues, using a technique involving sequential oxidation, β-elimination, and mild hydrolysis with acid. The molecular weight distribution of the resulting methylated oligosaccharides indicates that the 4- O-methyl- d-glucuronic acid residues are irregularly distributed in birch xylan.