The galactan sulphate of the red alga Polysiphonia lanosa.
The structure of the galactan sulphate of P. lanosa has been established by a combination of methylation, treatment with alkali, and partial methanolysis of the alkali-treated polysaccharide to give derivatives of agarobiose. The polysaccharide belongs to the agar class, in which 3-linked derivatives of beta-D-galactose alternate with 4-linked derivatives of alpha-L-galactose in a repeating sequence. In addition to D-galactose itself, the 3-linked units include 6-O-methyl-D-galactose, D-galactose 6-sulphate, and a hitherto unreported unit, 6-O-methyl-D-galactose 4-sulphate. The 4-linked units include L-galactose 6-sulphate, 2-O-methyl-L-galactose 6-sulphate, and 3,6-anhydro-L-galactose.
D005690:Galactose / Q000032:analysis; D011134:Polysaccharides / Q000032:analysis*; D000461:Rhodophyta / Q000032:analysis*; D013464:Sulfuric Acids / Q000032:analysis
D011134:Polysaccharides; D013464:Sulfuric Acids; D005690:Galactose