Optimization of Extraction and Purification of Polysaccharides from Veronicastrum axillare, and Evaluation of Their Biological Activities

Abstract

Veronicastrum axillare polysaccharides (VAP) were isolated by cellulase‐assisted digestion. The optimum conditions (2 % cellulase, 47 °C for 2.5 h, then, 95 °C for 2.5 h, pH 4.1, solid/liquid ratio 1 : 7.6) were identified by a combination of single factor optimization and response surface DOE (design of experiment) methods, and achieved a yield of 4.7 %. Treatment with 1 % TCA for 10 min, then, 2 % DEAE‐cellulose removed protein and colored impurities. Purified VAP retained most of the radical‐scavenging activities and GES‐1 cell protection capability in vitro, indicating VAP were the key active components of V. axillare. Some molecular features were identified by FT‐IR and NMR analyses. The molecular weight was estimated from DOSY NMR experiments to be around 21 kDa. There were 6.3 % uronic acid residues in the VAP. The constituent sugars after TFA hydrolysis were identified by HPLC to include glucose, arabinose, rhamnose, galactose, and xylose in a molar ratio of 405 : 259 : 82 : 42 : 1.

Recent developments in Moringa oleifera Lam. polysaccharides: A review of the relationship between extraction methods, structural characteristics and functional activities

“…The Sevag method is a classic method that is usually used in MOPs; this method makes glycosidic bonds difficult to break but needs to be repeated more than five times ( Sun, Zhang, & Fang, 2020 ). In addition, the trichloroacetic acid and polysaccharide solution under low-temperature stirring to remove colloidal proteins, but this method degrades a large number of polysaccharides containing furanose residues ( Qi et al, 2021 , Shi et al, 2019 ). The enzyme method is also used in purification MOPs.…”

Optimization of the Extraction Process and Antioxidant Activity of Polysaccharide Extracted from Centipeda minima

“…The sugar contents of CMP were measured using the phenol‐sulfuric acid method. The contents of protein and uronic acid were quantified with the Bradfords method and Bitters method [34–35] . The protein standard curve is: y=3.5229x + 0.0099, r 2 =0.9992, and that of glucuronic acid is: y=0.0084x + 0.0021, r 2 =0.9994.…”

Structure Elucidation of a Novel Polysaccharide Isolated from Euonymus fortunei and Establishing Its Antioxidant and Anticancer Properties

“…For further improving the yield of crude polysaccharide extraction from E. fortunei, the following fve parameters were considered: material-liquid ratio, extraction temperature, ultrasonic power, and extraction times. Te diferent values of these factors used for optimization involved the material-liquid ratios (20,30,40,50,60, and 70 mL/g); extraction temperatures (40,50,60,70,80, and 90 °C); ultrasonic power (144, 198, 252, 306, and 360 W); and extraction time at 15, 30, 45, 60, and 90 mins. By using the measured EFP content, the extraction rate (ER) has been computed.…”