The sulfated modification and antioxidative activity of polysaccharides from Potentilla anserine L

Abstract

The sulfated modification of polysaccharides from Potentilla anserine L (PAP_MAE) was studied. Three parameters, reaction time, reaction temperature and the ratio of chlorosulfonic acid (CSA) to pyridine, were optimized using Box–Behnken design (BBD) with a quadratic regression model built using response surface methodology (RSM). The optimal sulfated conditions for PAP_MAE were determined to be as follows: a reaction time of 3 h, a temperature of 59 °C, and a ratio of CSA to pyridine of 1 : 1; meanwhile, an experimental polysaccharide sulfur content of 16.15 ± 0.5% was achieved. The resulting SPAP was characterized by FT-IR. The monosaccharide composition was determined by a GC-MS method. The weight average molar mass (M_w) was determined by SEC-LLS. In addition, the antioxidant activity of PAP was investigated by measuring the scavenging abilities for DPPH, hydroxyl radicals and superoxide radicals, chelating to ferrous ions, and the reducing power in vitro. The results indicate that SPAP had good antioxidant activity.