羧甲基化龙眼肉多糖制备工艺优化及其抗氧化、免疫活性  

Optimization of Preparation of Carboxymethylated Polysaccharides from Longan(Dimocarpus longan) Pulp by Response Surface Methodology and Their Antioxidant Activity and Immunoregulatory Activity

作　　者：韦毅铭 何舟[2] 田海芬 王警[1] 吴妮妮[1] 黄静[1] 杨艳芳[1] 李雪华[1] 农真真 魏梅 潘欣 李果 

机构地区：[1]广西医科大学药学院,广西南宁530021 [2]广西壮族自治区人民医院,广西南宁530021 [3]百色市人民医院,广西百色533000

出　　处：《食品科学》2017年第22期275-283,共9页Food Science

基　　金：广西科学研究与技术开发计划项目(桂科重12118005-1-2);广西教育厅专利资助项目(KY2015ZL020)

摘　　要：利用响应面法优化羧甲基化龙眼肉多糖制备工艺,并测定其体外抗氧化活性,同时建立小鼠免疫低下模型,对所得多糖进行体内免疫调节活性研究。以羧甲基取代度为指标,通过单因素试验对一氯乙酸(monochloroacetic acid,MCA)浓度、反应温度、反应时间进行分析,得到羧甲基化龙眼肉多糖最佳制备条件为MCA浓度1.2 mol/L、反应温度73℃、反应时间3.2 h,取代度可达1.053。抗氧化活性研究表明,在质量浓度为200~3 200μg/mL范围内,龙眼肉多糖(polysaccharide from Dimocarpus longan pulp,LYP)、羧甲基化龙眼肉多糖(crboxymethylated polysaccharide from Dimocarpus longan pulp,CM-LYP)的抗氧化能力与质量浓度呈剂量依赖关系,当剂量质量浓度达3 200μg/mL时,LYP、CM-LYP对羟自由基清除率分别为(42.35±5.67)%、(84.39±4.47)%,对超氧阴离子自由基的清除率分别为(51.91±5.34)%、(87.91±7.32)%,对脂质过氧化的抑制率分别为(67.91±5.72)%、(79.85±2.92)%、对H2O2诱导的红细胞溶血的抑制率分别为(47.23±3.5)%、(54.66±2.83)%,表明羧甲基的引入增强了龙眼肉多糖的抗氧化活性;体内免疫活性实验表明,羧甲基化龙眼肉多糖可提高免疫抑制小鼠的脾脏指数、促进血清溶血素形成、提高血清和脾脏中溶菌酶含量及调节Th1/Th2平衡,与修饰前龙眼肉多糖相比,羧甲基化龙眼肉多糖具有更好的免疫调节作用。In this study, the carboxymethylation of polysaccharides（LYP） extracted from longan（Dimocarpus longan） pulp was investigated using monochloroacetic acid（MCA） with polysaccharides-to-MCA ratio, reaction time and reaction temperature as independent variables. The degree of substitution（DS） was taken as response value to optimize the important reaction conditions by response surface methodology. Meanwhile, the antioxidant activity and immunoregulatory of carboxymethlated polysaccharides（CM-LYP） in vivo were measured. The results showed that the optimized conditions that provided the maximum DS of 1.053 were determined as follows： reaction time, 3.2 h; MCA concentration, 1.2 mol/L; and reaction temperature, 73 ℃. The antioxidant activity of CM-LYP was concentration dependent in a certain range of concentration. The percentage inhibition of hydroxyl and superoxide anion radicals, lipid peroxidation, red blood cell hemolysis induced by H2 O2 were（42.35 ± 5.67）%,（51.91 ± 5.34）%,（67.91 ± 5.72）%, and（47.23 ± 3.5）% by LYP, and（84.39 ± 4.47）%,（87.91 ± 7.32）%, and（79.85 ± 2.92）%, and（54.66 ± 2.83） % by CM-LYP, respectively, implying that the antioxidant activity of LYP was improved as compared to the native polysaccharides. The immunoregulatory activity invivo showed that CM-LYP significantly improved spleen index in immunosuppressed, increased serum hemolysin level and lysozyme activity in serum and spleen, and maintained Th1/Th2 balance, and the effect was better than that of LYP.

关 键 词：龙眼肉多糖 羧甲基化 响应面法 抗氧化活性 体内免疫活性 

分 类 号：R284.3[医药卫生—中药学]