Structural and Hemostatic Activities of a Sulfated Galactofucan from the Brown Alga Spatoglossum schroederi

Abstract

The brown alga Spatoglossum schroederi contains three fractions of sulfated polysaccharides. One of them was purified by acetone fractionation, ion exchange, and molecular sieving chromatography. It has a molecular size of 21.5 kDa and contains fucose, xylose, galactose, and sulfate in a molar ratio of 1.0:0.5:2.0:2.0 and contains trace amounts of glucuronic acid. Chemical analyses, methylation studies, and NMR spectroscopy showed that the polysaccharide has a unique structure, composed of a central core formed mainly by 4-linked ␤-galactose units, partially sulfated at the 3-O position. Approximately 25% of these units contain branches of oligosaccharides (mostly tetrasaccharides) composed of 3-sulfated, 4-linked ␣-fucose and one or two nonsulfated, 4-linked ␤-xylose units at the reducing and nonreducing end, respectively. This sulfated galactofucan showed no anticoagulant activity on several "in vitro" assays. Nevertheless, it had a potent antithrombotic activity on an animal model of experimental venous thrombosis. This effect is time-dependent, reaching the maximum 8 h after its administration compared with the more transient action of heparin. The effect was not observed with the desulfated molecule. Furthermore, the sulfated galactofucan was 2-fold more potent than heparin in stimulating the synthesis of an antithrombotic heparan sulfate by endothelial cells. Again, this action was also abolished by desulfation of the polysaccharide. Because this sulfated galactofucan has no anticoagulant activity but strongly stimulates the synthesis of heparan sulfate by endothelial cells, we suggested that this last effect may be related to the "in vivo" antithrombotic activity of this polysaccharide. In this case the highly sulfated heparan sulfate produced by the endothelial cells is in fact the antithrombotic agent. Our results suggested that this sulfated galactofucan may have a potential application as an antithrombotic drug.

Sulfated fucans extracted from algae Padina gymnospora have anti-inflammatory effect

“…Immediately after, the supernatant was submitted proteolytic digestion with maxatase resulted in low protein contamination (Silva et al, 2005;Rocha et al, 2005b;Queiroz et al, 2006). This step was important because the sulfated fucans were usually bound to a large number of proteins.…”

Inhibitory effect of a Brazilian marine brown alga Spatoglossum schröederi on biological activities of Lachesis muta snake venom

“…These molecules are regularly produced via their primary or secondary metabolism, leading to the formation of polysaccharides (Camara et al, 2011) or diterpenes (Moura et al, 2010(Moura et al, , 2011, respectively. Rocha et al (2005) isolated polysaccharides from S. schröederi with potent in vivo antithrombotic effect upon venous thrombosis.…”

CARACTERIZAÇÃO E ATIVIDADE ANTICOAGULANTE DE POLISSACARÍDEOS SULFATADOS EXTRAÍDOS DA ALGA MARROM Dictyopteris justii

“…A extração de polissacarídeos sulfatados foi adaptada da metodologia descrita por Rocha et al (2005a). A alga após a coleta foi limpa com água corrente e seca em estufa aerada a 45° C. Posteriormente foi triturada e submetida a um processo de despigmentação e delipidação.…”