NMR characterization and anticoagulant activity of the oligosaccharides from the fucosylated glycosaminoglycan isolated from Holothuria coluber.

ABSTRACT

A glycosaminoglycan was isolated from the sea cucumber Holothuria coluber (HcFG). A series of oligosaccharide fragments (dp range 3-11) were prepared from its ß-eliminative depolymerized product (dHcFG). Extensive NMR characterization of the oligosaccharides indicated the d-GlcA-ß1,3-d-GalNAc4S6S repeating disaccharide backbone was substituted by monosaccharide branches comprising of Fuc2S4S, Fuc3S4S and Fuc4S, linked to O-3 of d-GlcA. For the prevailing Fuc3S4S at nonreducing end of dHcFG, the ß-eliminative depolymerization process of HcFG was compared with those of the FGs from Actinopyga miliaris (AmFG, branched with Fuc3S4S) and Stichopus variegatus (SvFG, branched with Fuc2S4S). The result suggested that d-GlcA substituted with Fuc3S4S was more susceptible to depolymerization than that with Fuc2S4S. It might be due to the larger steric hindrance effects from Fuc2S4S on the esterification of GlcA. Biological assays confirmed that the minimum chain length (dp8), regardless of the Fuc branch types, was required for the potent anti-iXase and anticoagulant activities in FG fragments.