新疆芜菁酸性多糖分离纯化、抗氧化活性研究及红外表征

目的 检测分离纯化的芜菁酸性多糖(Brassica rapaL.acidic polysaccharide,BRAP)的含量和纯度,并对其进行抗氧化能力检测和红外表征。方法 (1)经阴离子交换柱DEAE-650M、HW-55F色谱柱以及Sephacryl S-300色谱柱洗脱分离纯化芜菁多糖;(2)采取紫外-可见分光光度法及苯酚-硫酸法测定芜菁酸性多糖的含量;(3)经由测定芜菁酸性多糖羟基自由基(·OH)清除能力,1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基(·DPPH)清除能力、金属Cu²⁺还原能力来评价其抗氧化活性,并与VC抗氧化能力进行对比;(4)应用红外光谱分析芜菁酸性多糖的化学键或官能团信息,通过高效凝胶渗透色谱法对芜菁酸性多糖的均一性分析。结果 芜菁酸性多糖的含量为55.47%;芜菁酸性多糖对·DPPH和·OH有一定清除能力,对金属Cu²⁺也有还原能力,但均比VC弱,红外光谱分析显示,芜菁酸性多糖中有多羟基醛糖的特征吸收峰以及与抗氧化活性相关的羟基。高效凝胶渗透色谱图显示芜菁酸性多糖为高纯度多糖。结论 新疆芜菁中有含量较为丰富且纯度较高的酸性多糖组分,且该成分具有较好的抗氧化活性。

Isolation, purification, antioxidant activity exploration and infrared characterization of acidic polysaccharide from Xinjiang Brassica rapa L.

Objective To determine the content and purity of the Brassica rapa L. acidic polysaccharide (BRAP), and detect its antioxidant capacity and infrared characterization. Methods (1) The polysaccharides were separated and purified by anion exchange column DEAE-650M, HW-55F and Sephacryl S-300. (2) Ultraviolet-visible spectrophotometry and phenol-sulfuric acid method were used to determine the content of acidic polysaccharides in Brassica rapa L. (3) Antioxidant activity was evaluated by determining hydroxyl radical (·OH) scavenging ability, DPPH radical (·DPPH) scavenging ability and metal Cu2+ reducing ability, and compared with the antioxidant ability of VC. (4) The information of chemical bonds or functional groups contained in acidic polysaccharides of Brassica rapa L. by infrared spectroscopy, and the homogeneity of acidic polysaccharides of Brassica rapa L. was analyzed by high performance gel permeation chromatography. Results The content of acidic polysaccharides was 55.47%. The results showed that the acid polysaccharides had scavenging ability on ·DPPH and·OH, and reducing ability on metal Cu2+, but both of them were weaker than VC. The characteristic absorption peaks of polyhydroxyaldehydes and hydroxyl groups related to antioxidant activity were found in the BRAP and homogenicity analysis showed that it was high purity polysaccharide. Conclusion There are abundant and high purity acidic polysaccharides in Xinjiang Brassica rapa L., and this component has good antioxidant activity.