荔枝多糖级分的溶液性质研究

Study on the solution properties of polysaccharide fractions from litchi pulp

中文关键词:  荔枝  多糖级分  溶液性质

英文关键词:Litchi  Polysaccharide fractions  Solution properties

中文摘要:

      目的 研究荔枝多糖级分在溶液中的构象, 以丰富荔枝多糖的结构信息。方法 采用原子力显微镜(AFM)、圆二色谱(CD)、碘-碘化钾反应和激光粒度仪等方法分析各个级分的形态、结构以及粒径大小。结果 AFM分析表明LP1–4均含有分散的球状颗粒; LP2还含有较大的球状聚集物; LP3则出现部分蠕虫链状; LP4含有部分无规线团和支链交联状。CD分析发现LP3中含有不对称结构, 推测其为三股螺旋结构。碘-碘化钾实验发现LP1–4均存在较长的侧链和较多的支链。LP1–4的平均粒度分别是189.2、193.9、244.6和275.5 nm; 分散指数分别是0.301、0.463、0.479和0.518; LP1在溶液中呈无规卷曲状且未发生聚集, LP2–4则在溶液中有较大的聚集行为。结论 4种荔枝多糖级分具有不同的结构特征以及不同的溶液形态。

英文摘要:

      ABSTRACT: Objective To explore the solution properties of 4 polysaccharide fractions from litchi pulp. Methods Atomic force microscopy (AFM), circular dichroism (CD), iodine-potassium iodide reaction and laser particle size analyzer were used to analyze the solution conformation, structure and particle size of 4 polysaccharide fractions. Results AFM showed that LP1 was sphere-like conformation in solution. LP2 showed many large spherical particles aggregates. LP3 contained both spherical particles and rod-like structure. LP4 contained spherical particles and branched crosslinking structure. CD spectroscopy showed that there was an asymmetric structure in LP3, which would be a triple helix structure. LP1–4 existed longer and many branched side chains. The average particle sizes of LP1–4 were 189.2, 193.9, 244.6 and 275.5 nm, and their particle dispersion index were 0.301, 0.463, 0.479 and 0.518, respectively. LP1 was random coil and existed no aggregation in solution while LP2-4 existed a greater aggregation behavior in solution. Conclusion Four litchi polysaccharide fractions have different structural characteristics as well as different solution properties.