A xylan from perennial rye-grass (Lolium perenne)

Abstract

Alkaline extraction of perennial rye-grass herbage gave a xylan. Acid hydrolysis yielded L-arabinose, D-xylose, and an aldobiouronic acid consisting of D-xylose and 4-O-methyl-D-glucuronic acid. Hydrolysis of the methylated xylan gave 2,3,5-tri-O-methyl-L-arabinose, 2,3,4-tri-, 2,3-di-, and 2-O-methyl-D-xylose, and 3-O-methyl-2-O-(2,3,4-tri-O-methyl glucopyranosyluronic acid)-D-xylose. It is concluded that the polysaccharide is composed of chains of 1,4-linked β-D-xylopyranose residues to which are attached side chains of L-arabinofuranose units through position 3, and 4-O-methyl-D-glucuronic acid units through position 2 of the xylose residues.