Optimization Purification Process of Polysaccharides from Scutellaria baicalensis Georgi by Macroporous Resins and Its Antibacterial Activity

To optimize the purification conditions of polysaccharides extract from Scutellaria baicalensis Georgi by macroporous resin, the suitable macroporous resin was selected through performance comparison of static adsorption and elution of macroporous resins of different types, and the optimum conditions were confirmed by dynamic adsorption and elution tests. Meanwhile, the resistant abilities against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis were detected by filtering paper method. The results showed that the adsorption curves that AB-8 macroporous resin adsorbed polysaccharides of Scutellaria baicalensis Georgi accorded with the Langmuir mode feature. The optimum purification conditions were as follows: 60 mL polysaccharides extract solution of concentration 3 mg/mL (pH 5.0) was made and adsorbed by AB-8 macroporous resin with loading flow rate 2.0 mL/min, and then eluted by 75% ethanol with elution flow rate 1.0 mL/min. Under these conditions, the total polysaccharides content increased from 26.25% to 77.12%. The polysaccharides of Scutellaria baicalensis Georgi had inhibitory effects varying degrees on the four tested bacteria and the strongest inhibitory activity was resistant against Escherichia coli. The minimum inhibitory concentrations of Escherichia coli, Staphylococcus aureus, and Bacillus subtilis were 0.625, 0.625 and 1.25 mg/mL, respectively. This process had better purified efficiency, and polysaccharides after purification had better antibacterial activities, therefore it provides a reference for corresponding resource development.