Optimization of Extraction of Echinops lotifolis Tausch Polysaccharides and Its Antioxidant Activity

In this experiment,the extraction of Echinops lotifolis Tausch polysaccharides(ETP)was carried out by decoction and alcohol sedimentation technique. The extraction process of ETP was optimized by single factor experiments and response surface analysis,and the antioxidant activity in vitro was determined. The results showed that,the optimum extraction conditions for the polysaccharide were as follows:The ratio 1:20 g/mL(dry weight/water),reaction time 2 h,reaction temperature 100 ℃. The average extraction rate of polysaccharide under optimum conditions was 1.191%. The results of scavenging free radicals showed that the DPPH· clearance rate was up to 93.69%,the highest ·OH clearance rate was 97.44%,and the O₂^-· clearance rate was up to 67.96%. The results showed that the response to ETP was optimized. At the same time,good antioxidative activity could be obtained,which would provide a theoretical basis for its clinical application.