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.