A New .BETA.-D-Galactan Having 3-O-Methyl-D-galactose from Chlorella vulgaris.

Abstract

The neutral polysaccharide from Chlorella vulgaris K-22 cells has been shown by the fragmentationanalysis, methylation analysis, and periodate oxidation studies to be a new type of β-Dgalactanhaving 1, 3-linkages in the backbone and 1, 6-linkages in the side chain. This galactan alsocontains 6-ο-glycosylated 3-ο-methyl-β-D-galactose in the branching regions. The side chain has fourteen residues of D-galactose including 3-ο-metylated one(s). Mild acid hydrolysis of the galactan yielded three new disaccharides, 6-ο -(3-ο -methyl-β-D-galactopyranosyl)-D-galactopyranose, 6-ο-β-D-galactopyranosyl-3-ο -methyl-D-galactopyranose, and 6-ο -(3-ο -methyl-β-D-galactopyranosyl)-3-ο-methyl-D-galactopyranose, together with 3-ο-β-D-galactopyranosyl-D-galactose, 6-ο-β-Dgalactopyranosyl-D-galactose, and ο-β-D-galactopyranosyl-(1→6)-ο -β-D-galactopyranosyl-(1→6)-D-galactose.