RESUMO
A highly regular fucan sulfate SHFS was isolated from the sea cucumber Stichopus horrens by extraction of the body walls in the presence of papain followed by ion-exchange and gel permeation chromatography. SHFS had MW of about 140 kDa and contained fucose and sulfate in the molar ratio of about 1:1. Chemical and NMR spectroscopic methods were applied for the structural characterization of the polysaccharide. SHFS was shown to have linear molecules built up of 3-linked α-l-fucopyranose 2-sulfate residues. Anticoagulant properties of SHFS were assessed in vitro in comparison with the LMW heparin (enoxaparin) and totally sulfated 3-linked α-l-fucan. SHFS was found to have the lowest activity, and hence, both sulfate groups at O-2 and O-4 of fucosyl units seem to be important for anticoagulant effect of sulfated homo-(1 â 3)-α-l-fucans.
Assuntos
Anticoagulantes/química , Polissacarídeos/química , Pepinos-do-Mar/química , Animais , Espectroscopia de Ressonância Magnética , Estrutura MolecularRESUMO
A fucosylated chondroitin sulfate MM was isolated from the sea cucumber Massinium magnum. Structure of this polysaccharide was determined using chemical and NMR spectroscopic methods. The backbone of MM was shown to consist mainly of chondroitin sulfate E units with a small portion (about 10%) of chondroitin sulfate A fragments. Practically one type of branches Fuc3S4S attached to O-3 of GlcA residues was found in the polysaccharide molecules. The main repeating units of MM are â4)-[α-l-Fuc3S4S-(1â3)]-ß-d-GlcA-(1â3)-ß-d-GalNAc4S6S-(1â, whereas the minor repeating units are â4)-[α-l-Fuc3S4S-(1â3)]-ß-d-GlcA-(1â3)-ß-d-GalNAc4S-(1â. Anticoagulant activity of MM determined in APTT and TT tests was shown to be lower than that of heparin, but higher than that of enoxaparin. In the experiments with purified proteins MM effectively potentiated inhibition of thrombin and factor Xa by ATIII. Besides, MM did not induce platelets aggregation in platelets rich plasma.