Extraction, preliminary structural characterization, and antioxidant activities of polysaccharides from Salvia miltiorrhiza Bunge

► We extract four polysaccharides from Salvia miltiorrhiza Bunge using hot water, ultrasonic, alkali, and enzyme methods. ► We conduct preliminary structural characterization of four polysaccharides from Salvia miltiorrhiza Bunge by physicochemical property, FTIR and SEM. ► We evaluate the antioxidant activities of four polysaccharides from Salvia miltiorrhiza Bunge. ► The polysaccharides from Saliva miltiorrhiza Bunge may have potential applications in the medical and food industries.