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

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• 作者：Melissa Rabanal ; Nora M.A. Ponce ; Diego A. Navarro ; Ricardo M. G贸mez ; Carlos A. Stortz
• 关键词：Dictyota dichotoma ; Brown seaweeds ; Fucoidans ; Galactofucans ; Antiviral
• 刊名：Carbohydrate Polymers
• 出版年：30 January, 2014
• 年：2014
• 卷：101
• 期：Complete
• 页码：804-811
• 全文大小：901 K

文摘

Room-temperature acid (pH 2) extraction of Dictyota dichotoma thalli yielded 2.2% of sulfated polysaccharides. Further extraction with the same solvent at 70 掳C was conducted sequentially for nine times, with a total yield of 7.2%. Fucose was the main monosaccharide only in the room-temperature extract (EAR) and in the first 70 掳C extract (EAH1). The remaining fractions showed increasing amounts of mannose (the main neutral monosaccharide), xylose and uronic acids. Fractionation by means of cetrimide precipitation and redissolution in increasing sodium chloride solutions has allowed obtaining several subfractions from each extract. The fractions redissolved at lower NaCl concentrations have large amounts of uronic acids and lesser sulfate contents, whereas those redissolved at higher NaCl concentrations are heavily sulfated and have low uronic acid contents. For the fucose-rich extracts (EAR and EAH1), fractionation leads to uronoxylomannofucan-rich and galactofucan-rich fractions. The remaining extracts gave rise to complex mixtures, with mannose and uronic acid-rich polysaccharides. Moderate inhibitory effect against 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 fractions were also active against HSV-1.