Preparation and in vitro anticoagulant activities of alginate sulfate and its quaterized derivatives

Alginate sulfate (AS) and its ***quaterized derivatives (QAS-1, QAS-2, and QAS-3) were prepared from sodium alginate. Their structure was characterized by elemental analysis, FT-IR, 13C NMR, and gel permeation chromatography. The in vitro coagulation assay of human plasma containing the sulfates indicated that AS had considerably high anticoagulant activity especially to the intrinsic coagulation pathway. Its APTT reached 226 s at 16.7 μg/ml, comparing to that of heparin 125 s at 10 μg/ml. After quaterization the anticoagulant activities of QAS-1, QAS-2, and QAS-3 decreased as the degree of substitution of quaterization increased. The lowest one was given by QAS-3, which gave APTT as 260 s at 66.7 μg/ml, while AS did as 24 min at the same concentration. It could be concluded that AS could be used as a novel anticoagulant drug, and its quaterized derivatives, which contained a great many of sulfate groups but low anticoagulant activity, might have potential application in other field such as anti-HIV.