Structural investigation of water-hyacinth (Eichhornia crassipes) polysaccharides. Part I. Water-soluble polysaccharides

Abstract

A galactomannan and a branched (1 → 3)-β-D-glucan were isolated from the water hyacinth plant. The galactomannan, purified from the cold water extract, is composed of D-galactose and D-mannose in a ratio of 1.0:2.8. It has a (1 → 4)-linked D-mannose backbone, one out of three D-mannose residues being substituted with a single α-D-galactosyl unit. The branched (1 → 3)-β-D-glucan isolated from the hot water extract has a main chain composed of β-(1 → 3)-linked D-glucopyranosyl residues, and two single β(1 → 6)-D-glucopyranosyl groups attached as side chains to, on average, every 5 sugar units of the main chain. In addition, the branching of the β-glucan occurs regularly at O-6 of the β-(1 → 3)-linked backbone.