Molecular size is important for the safety and selective inhibition of intrinsic factor Xase for fucosylated chondroitin sulfate

Fucosylated chondroitin sulfate from sea cucumber Isostichopus badionotus (FCS- Ib ) showed potent anticoagulant activities without selectivity. The present study focused on developing safe FCS- Ib oligomers showing selective inhibition of intrinsic factor Xase (anti-FXase) prepared through partial N -deacetylation–deaminative cleavage. The N -deacetylation degree was regulated by reaction time, controlling the resulting oligomer distribution. Structure analysis confirmed the selectivity of degradation, and 12 high purity fractions with trisaccharide-repeating units were separated. In vitro anticoagulant assays indicated a decrease in molecular weight ( M w) dramatically reduced activated partial thromboplastin time (APTT), thrombin time (TT), AT-dependent anti-FIIa and anti-FXa activities, while the oligomers retained potent anti-FXase activity until they fell below 3   kDa. Meanwhile, human FXII activation and platelet aggregation were markedly reduced with decreasing M w and were moderate when under 12.0   kDa. Thus, fragments of 3–12.0   kDa should be safe and effective as selective inhibitors of intrinsic tenase complex for application as clinical anticoagulants.