【作者】 王峰；

【导师】 杨洋；

【作者基本信息】 广西大学 ， 发酵工程， 2013， 硕士

【摘要】 本文以绞股蓝为研究对象,研究其多糖的提取、分离纯化、化学结构、抗氧化作用、抑菌性能及其铁复合物的制备工艺,主要研究内容与结论如下：采用纤维素酶酶解法提取绞股蓝多糖,以加酶量、pH、时间和温度为考察因素,正交实验优化得到提取多糖最优工艺为纤维素酶(1000u/g)添加量2%,pH为6.0,酶解时间2.5h,酶解温度45℃,此条件下多糖得率为2.46%。通过对D301大孔树脂动态吸附除蛋白质的条件进行响应面优化,得到最佳条件为初提物浓度为2mg/mL、pH为6,上样体积为160mL(柱床体积500mL),流速为3mL/min; Sephadex G-200柱层析分级分离得到三种不同的多糖组分；HPLC检测结果显示,绞股蓝多糖组分GPI由甘露糖、鼠李糖、半乳糖醛酸、葡萄糖、半乳糖、木糖、阿拉伯糖7种单糖组成；红外光谱和核磁共振检测结果表明绞股蓝多糖存在呋喃结构。对比食品抗氧化剂Vc和绞股蓝多糖对体外自由基的清除能力,得到绞股蓝多糖具有较强的抗氧化性,但弱于Vc。通过测定抑菌圈直径的大小得到绞股蓝多糖对对细菌的抑制效果明显,对真菌无抑制作用。正交实验优化得到绞股蓝多糖铁复合物的制备的最佳条件为：三氯化铁与多糖的质量比为1：1,pH为8,反应时间为1.5h,温度为80℃。紫外光谱和红外光谱分析表明,Fe3+主要与绞股蓝多糖中的羟基结合,形成稳定的复合物。更多还原

【Abstract】 Gynostemma pentaphyllum Makino as research object, the extraction, isolation and purification, structural characterization, antioxidant activity, antimicrobial activity and the preparation of polysaccharide-iron complex of the polysaccharides from Gynostemma.pentaphyllum were studied in this thesis. The main research contents and results are as follows:The Gynostemma.pentahyllum polysaccharides (GP) was extracted by enzyme hydrolysis method. The orthogonal experiment were applied to optimize the extraction process with enzyme dosage, pH, enzymolysis time and temperature as factors, and the optimal conditions for the extraction of GP were determined:enzyme dosage2%, pH6.0, enzymolysis time2.5h, enzymolysis temperature45℃. Under this optimized extraction process, the yield of GP was2.46%.Four deproteinization methods were compared and found that the D301Weak Alkaline Big-aperture Resin performed better than other methods in terms of the protein removal efficiency. The optimal technological conditions for the resin adsorption process were obtained by using the response surface analysis. The optimal conditions were as follows:original extract concentration of2mg/mL, pH6.0, sample volume of160mL, and flow velocity of3mL/min. Three polysaccharide components were separated by Sephadex G-200column chromatography graded purification. Monosaccharide composition analysis of the GPI was carried out by HPLC, which indicated that the GPI consisted of mannose, rhamnose, galacturonic acid, glucose, galactose, xylose, arabinose. The results of IR Spectrum and nuclear magnetic resonance (NMR) suggested the presence of furan structure in the G. pentahyllum polysaccharides.The anti-lipid peroxidation, DPPH radical scavenging, hydroxyl radical scavenging and superoxide anion scavenging activities of Vc, the original GP extracts and the three purified polysaccharide components were studied to confirmed the antioxidant activity of the GP. The results demonstrated that the GP showed a strong antioxidant activity. Antibacterial effect of the GP was studied by measuring the diameter of inhibition zone. The polysaccharides had an obvious inhibitory effect on bacteria, but had no effect on fungi.The preparation technology of polysaccharide-iron complex was optimized by using the orthogonal experiment. The optimal complexation conditions were determined as the mass ratio of FeCl3and GP is1:1, pH8.0, reaction time of1.5h and temperature of80℃. Ultraviolet spectrum and infrared spectrum analysis indicated that the absorption peak of the hydroxyl in this complex had an obvious change, which illustrated that Fe3+mainly combined with hydroxyl of the GP to form a stable complex.更多还原