The system of fucoidans from the brown seaweed Dictyota dichotoma:Chemical analysis and antiviral activity

RABANAL MELISSA; NORA M.A. PONCE; NAVARRO DIEGO A.; RICARDO M. GOMEZ; CARLOS A. STORTZ

CARBOHYDRATE POLYMERS

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2014 vol. 101 p. 804 - 811

0144-8617

Room-temperature acid (pH 2) extraction of Dictyota dichotoma thalli yielded 2.2% of sulfated polysaccharides.Further extraction with the same solvent at 70 ◦C was conducted sequentially for nine times, with atotal yield of 7.2%. Fucose was the main monosaccharide only in the room-temperature extract (EAR) andin the first 70 ◦C extract (EAH1). The remaining fractions showed increasing amounts of mannose (themain neutral monosaccharide), xylose and uronic acids. Fractionation by means of cetrimide precipitationand redissolution in increasing sodium chloride solutions has allowed obtaining several subfractionsfrom each extract. The fractions redissolved at lower NaCl concentrations have large amounts of uronicacids and lesser sulfate contents, whereas those redissolved at higher NaCl concentrations are heavilysulfated and have low uronic acid contents. For the fucose-rich extracts (EAR and EAH1), fractionationleads to uronoxylomannofucan-rich and galactofucan-rich fractions. The remaining extracts gave riseto complex mixtures, with mannose and uronic acid-rich polysaccharides. Moderate inhibitory effectagainst herpes virus (HSV-1) and Coxsackie virus (CVB3) were found for the galactofucan-rich fractions.Most of the other fractions were inactive against both viruses, although some xylomannan-rich fractionswere also active against HSV-1.