Isolation and characterization of soluble sulfated polysaccharide from the red seaweed Gracilaria cornea

摘要: Abstract The composition, structure and rheological properties of a soluble sulfated polysaccharide from Gracilaria cornea (Brazilian red marine alga) were investigated. Agarocolloid yield, intrinsic viscosity, monosaccharide sulfate cation content as well molecular weight determined. main components 3,6-anhydrogalactose (24.7%) galactose (64.6%). In addition, minor such 6- O -methyl-galactose (8.5%), glucose (1.5%), xylose (0.7%) groups (4.8%) detected. Comparison between contents determined by Fourier transform IR (FT-IR) spectroscopy microelemental analysis was made. Data 13 C NMR FT-IR provided evidence sulfation in C-4 C-6 galactose. Sodium, calcium, magnesium potassium cations detected the agarocolloid. viscosities lower than typical values for agar same experimental conditions. No gelation 1.5, 2.0 3.0% (w/v) aqueous solution observed, even cooling up to 4 °C. Gel permeation chromatography indicated two major fractions M pk 7.4×10 4 1.8×10  g/mol fraction 2.1×10 6  g/mol, probably protein–polysaccharide complex.