System of polysaccharides of Codium decorticatum from the Patagonian coast

FERNÁNDEZ PV; RAFFO MP; CIANCIA M

Bali

Simposio; 21st International Seaweed Symposium; 2013

International seaweed asociation. Universitas Bakrie

Codium seaweeds, biosynthesize sulfated galactans constituted by 3-linked b-D-galactopyranose residues partially sulfated on C-4 and/or C-6, with ramifications on C-6 and important amounts of  pyruvate [1,2]. Besides, a highly sulfated pyranosic arabinan [2] and a 4-linked mannan, partially sulfated on C-2 [3], were also found. Codium decorticatum was collected in Puerto Madryn (Chubut, Argentina). The polysaccharides sulfated were obtained by water extraction at room temperature (D1 and D2) and then, at 90ºC (C1 and C2). The residue from the water extraction procedure was constituted by mannans (96 %). Analysis of the extracts showed that galactose and arabinose are the most important sugar components of D1 and D2, while C2 is constituted mainly by mannose and smaller amounts of glucose. All the extracts contained sulfate (23-10 %, as SO3Na). Attempts were made to fractionate D1 by precipitation with increasing KCl concentration, but most of the sample remained soluble in 2.0 M KCl solution and all the fractions contained similar amounts of the major monosaccharides. However, fractionation by ion exchange chromatography gave a fraction with 88 % of galactose (Fg) and another which contained 74 % of arabinose (Fa). Structural analysis of Fg showed the structural features characteristic of galactans of other species of Codium, with predominance of 4-sulfated units. Fa showed an arabinan structure, mainly sulfated on C-2. Fa will be tested as anticoagulant, taking into account that previous results showed the importance of sulfation on C-2 on the direct inhibition of thrombin [2]. [1] Bilan MI, Vinogradova EV, Shashkov AS, Usov AI, Carbohydr. Res. 342 (2007) 586–596. [2] Fernández PV, Quintana I Cerezo AS, Caramelo JJ, Pol-Fachin L, Verli H, Estevez JM,  Ciancia M, J. Biol. Chem. In press. http://www.jbc.org/cgi/doi/10.1074/ jbc.M112.386441. [3] Fernández PV, Estevez JM, Cerezo AS, Ciancia M, Carbohydr. Pol., 87 (2012) 916-919.