Fucosylated Chondroitin Sulfates from the Sea Cucumbers Paracaudina chilensis and Holothuria hilla : Structures and Anticoagulant Activity

Fucosylated chondroitin sulfates (FCSs) and were isolated from the sea cucumbers and , respectively. The purification of the polysaccharides was carried out by anion-exchange chromatography on a DEAE-Sephacel column. The structural characterization of the polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of nondestructive NMR spectroscopic methods. Both polysaccharides were shown to contain a chondroitin core [→3)-β-d-GalNAc (N-acethyl galactosamine)-(1→4)-β-d-GlcA (glucuronic acid)-(1→] , bearing sulfated fucosyl branches at O-3 of every GlcA residue in the chain. These fucosyl residues were different in their pattern of sulfation: contained Fuc2 4 and Fuc4 in a ratio of 2:1, whereas included Fuc2 4 , Fuc3 4 , and Fuc4 in a ratio of 1.5:1:1. Moreover, some GalNAc residues in were found to contain an unusual disaccharide branch Fuc4 -(1→2)-Fuc3 4 -(1→ at O-6. Sulfated GalNAc4 6 and GalNAc4 units were found in a ratio of 3:2 in and 2:1 in . Both polysaccharides demonstrated significant anticoagulant activity in a clotting time assay, which is connected with the ability of these FCSs to potentiate the inhibition of thrombin and factor Xa in the presence of anti-thrombin III (ATIII) and with the direct inhibition of thrombin in the absence of any cofactors.