Depolymerization of a fucosylated chondroitin sulfate from Cucumaria japonica: Structure and activity of the product

Abstract

Fucosylated chondroitin sulfate CJ from the body wall of sea cucumber Cucumaria japonica was depolymerized by the treatment with H₂O₂ in the presence of Cu(OAc)₂. The molecular weight of the polysaccharide was decreased from 32 kDa to 5 kDa. The product CJ-DP was shown to contain l-Fuc, d-GalNAc, d-GlcA, and sulfate in molar proportions of 0.96:0.90:1.00:5.4, which were quite similar to those of the parent polysaccharide CJ. The NMR analysis revealed that CJ-DP, like the parent polysaccharide CJ, consisted of both branched →4)-[3-O-α-l-Fuc]-β-d-GlcA-(1 → 3)-β-d-GalNAc-(1→ and linear →4)-β-d-GlcA-(1 → 3)-β-d-GalNAc-(1→ repeating blocks. Sulfate groups occupy O-4 and the majority of O-6 of GalNAc, as well as O-3 of GlcA, in linear blocks and different positions in Fuc branches. This result indicates that depolymerization practically does not diminish the amount of branches and sulfate groups in the product. Both polysaccharides CJ and CJ-DP demonstrated anticoagulant and hematopoiesis-stimulatory activities in vitro.

Keywords: Anticoagulant activity; Cucumaria japonica; Depolymerization; Fucosylated chondroitin sulfate; Hematopoiesis; Sea cucumber.