醇浸牛蒡根中水溶性多糖的提取及生物活性研究

Extraction and Bioactivities of Water-Soluble Polysaccharides from Ethanol-Soaked Roots of Burdock (Arctium lappa L.)

研究醇浸牛蒡根多糖的提取工艺及生物活性。以醇浸泡后的牛蒡根为原料,采用水提醇沉法,通过单因素和正交试验优化牛蒡根中水溶性多糖的提取工艺条件。结果表明:料液比1:25(g/mL)、提取时间2.5h、提取温度85℃、提取2次时,WPRA提取率为8.43%。WPRA经Sevag法脱蛋白后,用紫外光谱、红外光谱进行表征,证明产物可能为含有肽键的多糖类物质。体外抗氧化性实验表明,WPRA对DPPH自由基具有一定的清除能力,对超氧阴离子自由基清除能力较弱。抑菌实验表明WSPA对受试菌株基本没有抑制作用。

After having been soaked in 80% ethanol, burdock roots were used for the extraction of water-soluble polysaccharides by water extraction and ethanol precipitation. The optimal extraction conditions, as established by one-factor-at-a-time and orthogonal array designs, were 1：25 （g/mL）, 2.5 h and 85 ℃ for solid/solvent ratio, time and temperature, respectively, and the extraction was repeated twice. Under the optimized conditions, the yield of water-soluble polysaccharides from burdock roots was 8.43%. The crude polysaccharides were deproteinized by Sevag＇s method and characterized by UV and infrared spectroscopy. The purified products might be polysaccharides bound with peptide bonds. In vitro antioxidant assays suggested that the polysaccharides had marked DPPH free radical scavenging activity, but weak superoxide anion radical scavenging activity. In addition, they had no inhibitory effects on E. coli, S.aureus or B.subtilis.