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

Four polysaccharides were extracted from Salvia miltiorrhiza Bunge using hot water, ultrasonic, alkali, and enzyme methods. Preliminary structural characterization was conducted by physicochemical property, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses. Antioxidant activities against 2,2-diphenyl-1-picryl-hydrazyl (DPPH), hydroxyl, and superoxide radicals were also evaluated. The physicochemical property analysis indicated the identicalness of the polysaccharide indices obtained by the hot water and ultrasonic methods. The indices obtained by the alkali and enzyme methods were significantly different. The FTIR spectra revealed the general characteristic absorption peaks of the four polysaccharides. The SEM images demonstrated significant differences in the surface features of the different polysaccharides. The antioxidant activity assay revealed the significant antioxidant activities of three polysaccharides. Overall, the polysaccharides from S. miltiorrhiza Bunge may have potential applications in the medical and food industries.