Extraction And Biological Activities Of Polysaccharides From Chrysanthemum Morifolium

Chrysanthemum morifolium (CM) was considered as a type of traditional medicine and healthy food containing nutritional components and active substances. In this work, polysaccharide was extracted from CM by hot water extraction (CMP-H), ultrasonic-assisted extraction (CMP-U), and alkaline extraction (CMP-A). This research aims to investigate the influence of extraction methods on the physicochemical properties and biological properties, optimize the extraction process to increase the extraction yield, ensure higher activity of polysaccharide, and improve the utilization value. The main results were as follows:1. The three different methods to extract polysaccharide from CM were studied systematically. Depending on the results of polysaccharide extraction yield in single-factor experiments, this research optimized the experimental conditions of these three methods respectively via response surfaces analysis methods based on the Box-Behnken center-united experimental design principle. The results showed that, the best conditions to extract CMP by hot water were extraction temperature of 86?, solid-liquid ratio of 1:25 g/mL, partial size of 80 mesh powder, and extraction time of 2.1 h for one time. Under these conditions, the extraction yield of CM polysaccharide (CMP-H) was 7.95%. The optimum parameters for ultrasonic-assisted were ultrasonic time of 27 mins, ultrasonic temperature of 61?, solid-liquid ratio of 1:25 g/mL, and ultrasonic power of 104 W. with the highest extraction yield of CM polysaccharide (CMP-U) 8.38% in three methods. The best conditions of extracting CMP with alkaline were NaOH concentration of 0.40 mol/L, extraction temperature of 89?, extraction time of 2.0 h, and solid-liquid ratio of 1:26 g/mL with extraction rate 7.79% of CM polysaccharide (CMP-A). Rerult of Scanning electron microscopy (SEM) demonstrated that the extent of the cell walls damage was most serious among by ultrasonic-assisted extraction method, which lead to the largest amount of polysaccharide dissolved. The proteins of CMP-U were removed by enzyme method, the elimination ratio of proteins and the retention value of polysaccharide was 78.93% and 68.42%. Therefore, ultrasonic-assisted method is the best method.2. The results of physicochemical properties of the three polysaccharides in vitro indicated that polysaccharide extracted via these three methods were soluble in water, insoluble in organic solvents, consisting of neutral sugar, uronic acid and protein. Moreover, polysaccharide extracted from the hot water as well as alkaline methods mainly contained neutral polysaccharide-based, and content of sugar uronic acid was 1.60% and 1.08% respectively, while the ultrasound assisted extraction method mainly contained acidic polysaccharose and uronic acid reached at 7.03%. Emulsification and emulsion stability studies showed that the polysaccharide concentration, salt concentration and pH conditions had effects on their results, with significant difference. The SEM's results indicated that surface of polysaccharide extracted by hot water extraction was smooth and neat, while the results via ultrasonic-assisted extraction and alkaline extraction were rough and rugged with many caves.3. Antioxidant activity of polysaccharide (including reducing power and scavenging effect toward hydroxyl radical, superoxide anion radical and hydrogen peroxide) from the three methods in vitro were investgated. The total reduction of capacity analysis showed that when the polysaccharide concentration was 1.0 mg/mL, CMP-U and CMP-A reached to the maximum capacity,62.30% and 47.87% respectively, were significantly better than the same scavenging effect of CMP-H; The values of IC50 of CMP-U and CMP-H radical scavenging DPPH were 0.30 and 0.59 mg/mL respectively, while that of CMP-A scavenging capability was weak. The results of inhibition experiments of enzymes of a-glucosidase by CMP-H, CMP-A and CMP-U showed that CMP-A had no effect on the enzyme activity of a-glucosidase, while the opposite results were observed for CMP-H and CMP-U. The IC50 concentrations of CMP-H and CMP-U were 0.58 and 0.70 mg/mL. CMP-H?CMP-A and CMP-U had no inhibition on the enzyme activity of ACE. The binding capacity of bile salts of the three kinds of CMP extracts were studied the bile salts binding capability. The result showed that 3 kinds extract of CM had better adsorption effect. The IC50 concentrations of CMP-H, CMP-A and CMP-U were 0.38,0.48 and 0.49 mg/mL respectively.