Depolymerization of fucosylated chondroitin sulfate from sea cucumber, Pearsonothuria graeffei, via 60Co irradiation

A method for depolymerization of a novel fucosylated chondroitin sulfate from Pearsonothuria graeffei (fCS-Pg) using (60)Co irradiation in water solution was developed in the current study. Fragments with varying molecular weights were obtained by (60)Co irradiation at different dosages and sample concentrations. The chemical compositions and structures of these fragments were further investigated using high-performance liquid chromatography (HPLC), infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Our results indicated that (60)Co irradiation induced depolymerization via selective breakage of glucuronic acid units in the fCS-Pg backbone, with no obvious influence on sulfated fucose branches under mild conditions. The recommended conditions for fCS-Pg degradation were 2-10% solution concentration and irradiation dosages of 10-50kGy. The anticoagulant activities of the low molecular weight fragments were additionally evaluated. Notably, anticoagulant activities were reduced with decreasing molecular weights. Compared to the native fCS-Pg, low molecular weight fragments displayed significantly decreased anticoagulant activities. Based on the collective findings, we propose that these fragments are potentially applicable as antithrombotic agents with reduced bleeding risk relative to native fCS-Pg.