Sulfated modification, basic characterization, antioxidant and anticoagulant potentials of polysaccharide from Sagittaria trifolia

To discover novel antioxidants and anticoagulants for the prevention and treatment of cardiovascular diseases remains ongoing concern. Sagittaria trifolia is a commonly consumed aquatic vegetable with highly nutritious value and wide planting area in China. Polysaccharides are the major bioactive constituents, but little information is available on anticoagulant potential. In this work, a polysaccharide from S. trifolia (PST) was modified by sulfation to produce four sulfated derivatives (SPST-1 ∼ 4), and their antioxidant and anticoagulant potentials were evaluated. Various means of analysis confirmed the success of sulfation on PST. The unmodified PST possessed notable antioxidant and pro-coagulant activities. To some extent, sulfated modification reduced the antioxidant capacity of PST with the increase of degree of substitution (DS), but for the derivative SPST-4 with moderate DS and smallest molecular weight (MW) exerted better antioxidant activity, in particular of scavenging nitrogen-containing radicals. Interestingly, sulfation reversed the innate activity of PST from pro-coagulation to anticoagulation, which highly depended on DS. The derivative SPST-3 with highest DS and moderate MW elicited promising anticoagulant potential, particularly at concentration of 5.00 mg/mL, which was superior to that of heparin (positive control) in the aspect of prolonging thrombin time and prothrombin time. Herein, the present contribution would give evidence that PST and sulfated derivatives SPST-3 and SPST-4 own potentials to be developed as hemostatic, anticoagulant, and antioxidant candidates, respectively.