The components and activities analysis of a novel anticoagulant candidate dHG-5

Intrinsic Xase (iXase), the last and rate-limiting enzyme complex in the intrinsic coagulation pathway, may be an ideal target for antithrombotic treatment. A depolymerized fraction of fucosylated glycosaminoglycan from sea cucumber Holothuria fuscopunctata, dHG-5 (Mw 5.2 kDa), showed potent and selective inhibition of iXase (IC₅₀, 14 nM). In this work, the series of oligosaccharides contained in dHG-5 were purified and their precise structures were confirmed by 2D NMR and MS spectra. The relationships between anti-iXase, f.IXa-binding, anticoagulant and antithrombotic activities (y) and molecular weight (x) could be approximately expressed as the power function (y = a × x^b), and these activity potencies of dHG-5 were approximately equivalent to the weighted average sum of that of its oligosaccharides. Given the prominent pharmacological properties, well-defined chemical composition and explicable relationships between dHG-5 and its oligosaccharides in pharmacological behaviors, dHG-5 is expected to be an ideal novel anticoagulant medicine.