Highly substituted polysaccharides from green seaweeds (Ulvophyceae) with anticoagulant activity

PAULA X. ARATA; IRENE QUINTANA; MARINA CIANCIA

Buenos Aires

Simposio; First Argentinian Symposium of Glycobiology "GlycoAR 2014"; 2014

CONICET/UBA

Sulfated and/or pyruvylated polysaccharides from green seaweeds with anticoagulant activity Arata P.X. 1*, Quintana I.3, Ciancia M. 1,2 1Cátedra de Química de Biomoléculas, FAUBA; 2CIHIDECAR-CONICET-FCEN-UBA 3Dpto. Química Biológica FCEN * aratapau@agro.uba.ar Ulvophycean seaweeds synthesize sulfated polysaccharides, an adaptation to the marine habitats. The structures of the major sulfated polysaccharides from two species, belonging to this class but to different orders were studied: Penicillus capitatus (Bryopsidales) and Cladophora falklandica (Cladophorales) The room-temperature water extracts of both seaweeds were fractionated by ion exchange chromatography, giving major fractions (PF1 and CX2, respectively) that were studied. Their structural analysis showed great differences between them. While P. capitatus produces mainly sulfated highly pyruvylated 3-linked galactans, C. falklandica synthesizes complex sulfated polysaccharides, comprising 4-linked pyranosic arabinan partially substituted on C-3 or C-2 and C-3 with sulfate or single stubs of xylose and furanosic galactose units. Anticoagulant properties of PF1 and CX2 were evaluated using PT (Prothrombin Time), APTT (Activated Parcial Thromboplastin Time) TT (Thrombin Time) and fibrin formation assays. TT-like assays were also performed with purified fibrinogen instead of plasma in order to evaluate if one of the mechanisms could be direct thrombin inhibition. The most powerful effect was observed in the TT test by PF1, but both fraction significantly prolonged APTT and TT, in concentration dependent manner. Besides, the most important mechanism for PF1 would be direct inhibition of thrombin, while for CX2 direct and indirect mechanisms would be involved.