金莲花多糖的分离纯化及其抗氧化作用研究

Purification and anti-oxidant activity of polysaccharide isolated from Trolliouschinensis

目的研究金莲花多糖的分离纯化及其体外抗氧化活性。方法常规回流提取、乙醇沉淀得到金莲花粗多糖,经AB-8大孔吸附树脂脱色、脱蛋白后得精制的金莲花多糖(Trollius chinensis Bunge polysaccharide,TCBP),以蒸馏水为洗脱剂,经DEAE-52纤维素离子交换层析和Sephadex G-150凝胶过滤柱层析得一纯化的金莲花纯多糖,采用高效凝胶过滤色谱法鉴定所得组分纯度并测定其相对分子质量,通过高效液相色谱分析多糖的单糖组成。通过水杨酸-Fe2+-H2O2体系、二苯代苦味肼基自由基(DPPH)体系和邻苯三酚自氧化法对分离纯化的金莲花多糖组分的抗氧化能力进行研究。结果该多糖分子量为3 283 220 Da;单糖组成为鼠李糖、D-半乳糖、阿拉伯糖;单糖物质的量之比为0.84∶1∶1.16。具有清除·OH的能力,但对·DPPH和·O-2没有清除作用,相反诱导·O-2的产生,且随着浓度的增大,邻苯三酚自氧化程度也增强。结论金莲花纯多糖为一杂多糖,具有一定的抗氧化活性,首次从金莲花中分离得到。

AIM To study purification and anti-oxidant activity of polysaccharide isolated from globeflower （ Trollious chinensis）. METHODS The method of reflux extraction was adopted to extract polysaccharide from T. chinensis. AB-8 resin can be used to remove pigment and protein of T. chinensis polysaccharide. DEAE-52 cellu- lose ion exchange column and Sephadex G-150 gels filter column were sequentially used to further purify crude pol-ysaccharides, and then their molecular weight and momosaccharide composition were measured by high performance gels filtration chromagraphy and HPLC, respectively. Anti-oxidative capability of polysaccharide was determined by salicylic-Fez＋ -H202 system, DPPH system, and means of pyrogallol oxidation. RESULTS Polysacchatide from Globeflower was obtained with a relative molecular weight of 3283220 Da consisting of Rha, Gal, and Ara, （molar ratio of 0. 8d ： 1 ： 1.16）. Polysaccharide from Globeflower exhibited strong scavenging capacity for hydroxyl radi- cal, but had no effect on cleaning ~ DPPH and scavenging superoxide anion free radicals. The latter had an as- cending tread with the increasing of polysaccharide concentration. CONCLUSION Polysaccharide from Globe- flower is a complex polysaccharide with certain antioxidant activity.