Abstract
An aldo-tetrouronic acid has been isolated by enzymatic hydrolysis of a 4-O-methylglucuronoxylan from the wood of white birch. It has been shown to be O-4-O-methyl-[alpha]-D-glucosyluronic acid-(l[long dash]2)-0-[beta]-D-xylopyranosyl-(1[long dash]4)-O-B-D-xyloxul-(l[forward arrow]4)-D-xylose.