Structural and compositional characteristics of gelling galactan from the red alga Ahnfeltia tobuchiensis(Ahnfeltiales,the Sea of Japan)

摘要

The composition and structure of a sulfated polysaccharide from Ahnfeltia tobuchiensis,a red seaweed of Kuril Islands and Japan,were investigated.Samples of the galactan were characterized by ~(13)C NMR and FTIR spectroscopy and chemical analysis in comparison with well-known commercial agarose preparations.The main components of the polysaccharide from A.tobuchiensis were 3,6-anhydro-L-galactose(38 +-4.5%)and galactose.Methoxy groups(2.2%)of the galactan are located in the position 2 of the anhydrogalactose residues.The galactan proved to be a high-sulfated agarose.Sulfur content of this polysaccharide is 0.2-0.3%,and sulfate groups may be removed by alkali treatment to a limited extent only.The precision of quantification and possibilities of analytical methods used are discussed.