枸骨果多糖的分离纯化和单糖分析及抗氧化特性

Extraction,purification,monosaccharide analysis and antioxidant characteristics of polysaccharide from Ilex cornuta fruits

【目的】优化枸骨果多糖超声辅助提取工艺条件,分离、纯化粗多糖,得到均一多糖后对其单糖组成和抗氧化能力进行测定。【方法】根据单因素试验结果,利用Design Expert软件设计正交试验优化了枸骨果多糖的提取工艺。粗多糖经三氯乙酸(trichloroacetic acid,TCA)法除蛋白后,使用柱层析分级纯化,得到均一多糖LCFP-3。通过高效离子色谱法测定LCFP-3的单糖组成,通过DPPH自由基清除能力及总还原力的测定,评估LCFP-3的抗氧化能力。【结果】最佳工艺条件:超声时间、超声温度、液料比分别以53 min、63℃、26 mL∶g,此条件下多糖得率为2.36%。LCFP-3的总糖含量为90.31%,蛋白含量为0.246%,分子量为41199 U,主要由半乳糖(31.92%)、阿拉伯糖(25.87%)、半乳糖醛酸(23.35%)组成,并含有少量鼠李糖、葡萄糖、甘露糖和木糖。LCFP-3质量浓度为50 mg/mL时对DPPH自由基的清除率为79.0%,质量浓度在3~25 mg/mL范围内与还原力有良好的线性关系。【结论】从枸骨果中提取纯化了一种多糖LCFP-3,对其化学性质进行分析表明其具有抗氧化活性。

【Objective】To optimize the extraction conditions of polysaccharides,to separate and purifie the crude polysaccharides,and to determine the monosaccharide composition and antioxidant capacity.【Method】According to the results of single factor experiment,orthogonal experiment was designed and optimized by using Design Expert software.LCFP-3 was purified by column chromatography after removing protein with trichloroacetic acid(TCA)method.Monosaccharide composition of LCFP-3 was determined by high performance ion chromatography.The antioxidant capacity of LCFP-3 was evaluated by DPPH radical scavenging ability and total reducing power.【Result】The optimal conditions were as follows:ultrasonic time,ultrasonic temperature and liquid-solid ratio were 53 min,63℃and 26 mL∶g,respectively.Under these conditions,the yield of polysaccharide was 2.36%.LCFP-3 contained 90.31%of total sugar,0.246%of protein,and its molecular weight was 41199 U.LCFP-3 was mainly composed of galactose(31.92%),arabinose(25.87%),galacturonic acid(23.35%),and a small amount of rhamnose,glucose,mannose and xylose.When LCFP-3 concentration was 50 mg/mL,the scavenging rate of DPPH free radical was 79.0%,and there was a good linear relationship between LCFP-3 concentration and reducing power while LCFP-3 concentration was 3 to 25 mg/mL.【Conclusion】A polysaccharide LCFP-3 was extracted and purified from Ilex cornuta fruits.The chemical properties of LCFP-3 showed that it had antioxidant activity.