Comparison of Polygonatum sibiricum Polysaccharides from Different Extraction Methods

Although our previous research has indicated that the ultrasound-assisted extraction–deep eutectic solvent method possessed the highest extraction yield for Polygonatum sibiricum Polysaccharide, it is uncertain whether the Polygonatum sibiricum Polysaccharide that was extracted by the ultrasound-assisted extraction–deep eutectic solvent method possesses the same performance as that extracted by other methods and whether separation and purification affect the performance of Polygonatum sibiricum Polysaccharide. This paper aimed to compare the differences in performance among the Polygonatum sibiricum Polysaccharides extracted using different methods, including the ultrasound-assisted extraction–deep eutectic solvent method, which was the first method used by our team to extract Polygonatum sibiricum Polysaccharide. This paper also aimed to compare the differences in Polygonatum sibiricum Polysaccharides before and after they were separated and purified. The extraction yield, structural composition, and antioxidant activity of Polygonatum sibiricum Polysaccharides were compared, respectively. The extraction yield (45.08%) obtained by the ultrasound-assisted extraction–deep eutectic solvent method was the highest (p < 0.05), the structural compositions of Polygonatum sibiricum Polysaccharides extracted using different methods were similar, and the separated and purified Polygonatum sibiricum Polysaccharide was a neutral polysaccharide. The 2,2–diphenyl–1–picrylhydrazyl and 2,20–azino–bis (3–ethylbenzothiazoline–6–sulfoniacid) levels in the Polygonatum sibiricum Polysaccharide extracted by the ultrasound-assisted extraction–deep eutectic solvent method were significantly higher than those obtained using other methods (p < 0.05), and the antioxidant activity of the Polygonatum sibiricum Polysaccharide extracted by this method was significantly higher after it was separated and purified (p < 0.05). This study not only proved that the ultrasound-assisted extraction–deep eutectic solvent method could increase the extraction yield and keep the structural composition and antioxidant activity of Polygonatum sibiricum Polysaccharide at the maximum levels but also confirmed that the extracted Polygonatum sibiricum Polysaccharide should not be further separated and purified, providing a potential technique to extract Polygonatum sibiricum Polysaccharide. This study will further promote the application of Polygonatum sibiricum Polysaccharides in the health product industry.