Anticoagulant activity of sulfoalkyl derivatives of curdlan

Curdlan is a natural beta -1,3-glucan produced by Agrobacterium biovar 1. I n this study, the anticoagulant activity of sulfoalkyl derivatives of curdl an was investigated by carrying out activated partial thromboplastin time ( APTT) assay and compared with that of o-sulfonated curdlan. Approximately 1 00-fold higher concentration of o-sulfonated curdlan than heparin was requi red to obtain the same level of the clotting time. Anticoagulant activity o f curdlan derivatives was dependent on the degree of sulfation in prolongin g the clotting time. However, the chain length of the substituent did not p lay a role in prolonging the clotting time. The curdlan derivatives enhance d thrombin inhibition by mediating through antithrombin ill. The inhibition of thrombin by o-sulfonated curdlan was found to be approximately 10-fold weaker than that by heparin.