Physicochemical characteristics and anticoagulant activities of low molecular weight fractions by free-radical depolymerization of a fucosylated chondroitin sulphate from sea cucumber Thelenata ananas

A process of depolymerization of a new fucosylated chondroitin sulphate from Thelenata ananas by free-radicals was developed. The fractions with different molecular weights and a narrow molecular weight distribution was obtained. The products were characterised by physicochemical properties, FT-IR spectra and NMR spectra. The results confirm the retention of primary structure of the fractions after the depolymerization. Furthermore, the anticoagulant activity of the fractions was evaluated by the activated partial thromboplastin time (APTT). The APTT activity decreases in proportion to the molecular weight following a logarithmic-like function, and the potentiating of prolongation of APTT activity requires at least an oligosaccharide chain of about 6–8 units (6000–7000 Da). Compared to high doses of low molecular weight heparin (LMWH), a more desirable molecular weight fraction (13,950 Da) demonstrates significantly lower anticoagulant activity. Thus, the fraction has more potential as an antithrombotic agent with reduced bleeding risk relative to LMWH.