红景天多糖的提取及体外抗氧化活性研究

目的优化红景天多糖的制备工艺,并系统评价红景天多糖清除自由基的能力.方法采用正交设计方法优化红景天多糖提取工艺,以多糖提率为考察指标,比较不同固液比、提取温度、提取时间、提取次数对多糖提取效果的影响;通过反复冻融、透析及酶-sevag联合脱蛋白法,纯化制备红景天多糖(RSP);采用苯酚-硫酸法、红外色谱仪及紫外-可见分光光度计对红景天多糖的基本理化性质进行表征;利用体外抗氧化模型评价红景天多糖对1,1-二苯基-2-苦苯肼自由基(DPPH·)、羟基自由基(·OH)和超氧阴离子(O_2~-·)自由基的清除能力.结果红景天多糖的最佳提取条件固液比为1∶20,提取温度为90℃,提取时间为3 h,提取次数3次.此外,红景天多糖对DPPH·和·OH具有较好的清除能力.结论成功确立红景天多糖的最佳提取工艺,红景天多糖具有一定的抗氧化作用.

Study on the Extraction of Polysaccharide from Rhodiola Rosea and Its Antioxidant Activity in Vitro

Objective To establish the optimum process for the extraction of Rhodiola rosea polysaccharides ( RSP ) ,and to evaluate their free radical scavenging capacities. Method The optimum extraction conditions were obtained by orthogonal experiment design. Taking the crude polysaccharide content as index,the influences of solid-liquid ratio,extraction temperature,extraction time,extraction times on the extraction efficiency were compared. The proteins in Rhodiola rosea polysaccharides were removed by repeated freezing and thawing,dialysis,and enzyme-sevag method,in order to acquire relatively pure polysaccharides. The basic physical and chemical properties of Rhodiola rosea polysaccharides were characterized by phenol-sulfuric acid method, infrared chromatography and UV-visible spectrophotometer. The antioxidant system was introduced in vitro. The scavenging effects of Rhodiola rosea polysaccharides on three free radicals were determined,including 1,1-diphenyl-2-picrylhydrazyl (DPPH ·), hydroxyl radical ( · OH ) and superoxide anion ( O-2 · ) . Results The optimal extraction conditions were as follows:solid-liquid ratio of 1 ∶ 20,extraction temperature of 90 ℃,3 extraction times,extraction time of 3 h. In addition,Rhodiola rosea polysaccharides exhibited excellent scavenging abilities on DPPH · and · OH free radicals. Conclusion Optimum extraction technology of Rhodiola rosea polysaccharide is successfully established, in addition,Rhodiola rosea polysaccharides have certain antioxidant effect.