信阳毛尖茶末多糖的分离纯化和体外抗氧化活性研究

为实现废弃茶叶资源的再利用以及探究信阳毛尖茶叶末活性多糖的体外抗氧化活性,本研究首先利用不同的乙醇终浓度沉淀优化毛尖茶粗多糖提取,然后通过DEAE-52纤维素和Sephadex-100葡聚糖凝胶分级两次纯化,并进行纯度鉴定、分子量的测定、红外光谱分析以及体外抗氧化活性的测定等。研究结果表明,90%的乙醇终浓度得率最高,为2.47%;两次分级纯化后得到XPS-5B,纯度分别为92.4%;XPS-5B符合活性植物多糖结构特征,为β-型糖苷键多糖,分子量为41208 Da;XPS-5B体外抗氧化活性随着组分浓度的增加而逐渐增强,当XPS-5B浓度为1.20 mg/mL时对DPPH自由基和羟自由基的清除率分别为89.18%、90.62%,总还原力吸光值为0.536,与未纯化的毛尖粗多糖相比,具有较强的抗氧化活性。

Isolation,Purification and in Vitro Antioxidant Activity of Tea Dust Polysaccharide from Xinyangmaojian

To achieve the reuse of the waste tea resources and explore the activity in vitro antioxidant activity of Xinyangmaojian tea dust polysaccharide, in this study, different concentration of final ethanol precipitation was used to optimize Xinyangmaojian tea polysaccharide extraction. Then the crude polysaccharides were separated and purified twice by DEAE-52 cellulose and Sephadex-100 dextran gel, and the pure polysaccharides, purity identification, determination of molecular weight, infrared spectroscopy and in vitro antioxidant activity were conducted. The results showed that the yield rate of 90% ethanol was the highest (2.47%). After two times of fractional purification, XPS-5B was obtained with the purity of 92.4%. XPS-5B conformed to the structural characteristics of polysaccharides from active plants, and glycosidic polysaccharide was of type β, with a molecular weight of 41208 Da. The antioxidant activity of XPS-5B increased gradually with the increasing of component concentration. When the concentration of XPS-5B was 1.20 mg/mL, the scavenging rate of DPPH free radical and hydroxyl free radical was 89.18% and 90.62%, respectively. The total reducing power absorbance value was 0.536, compared with the unpurified polysaccharides, XPS-5B had strong antioxidant activity.