College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China.
College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China; Bioactive Products Engineering Research Center For Gansu Distinctive Plants, Northwest Normal University, Lanzhou 730070, People's Republic of China.
Int J Biol Macromol. 2020 May 1;150:189-199. doi: 10.1016/j.ijbiomac.2020.02.031. Epub 2020 Feb 10.
Interest in galactomannans and its derivatives as a functional health supplement is growing based on physicochemical properties. In this work, the optimized conditions of sulfated tara gum (STG) with a maximum DS of 0.66 by box-behnken design (BBD) were obtained as following: ratio of chlorosulfonic acid/pyridine 3:1, reaction time 4 h and reaction temperature 40 °C. The structure features of STG such as the degree of substitution (DS), substitution position, weight average molar mass (M), monosaccharide components and chain conformation were investigated. Decreasing of M, the increasing of Z-average radius of gyration (〈S〉) and specific volume for gyration (SV) were obtained by SEC-MALLS. In addition, the structural properties of four sulfated galactomannans were comparatively investigated and analyzed based on our earlier reports of sulfated fenugreek gum, guar gum and locust bean gum. A conclusion was drown that higher galactose branch could enhance steric hindrance, which was inferred as one of the significant factors for the derivatization efficiency, thus affecting the DS, M and conformational transition of sulfated galactomannans. This study will provide valuable information for further research on the comparison of bioactivities and medical application of galactomannans family.
基于理化性质，半乳甘露聚糖及其衍生物作为一种功能性保健品的兴趣日益浓厚。在这项工作中，通过 Box-Behnken 设计（BBD）获得了最大取代度（DS）为 0.66 的硫酸塔拉胶（STG）的优化条件如下：氯磺酸/吡啶比为 3:1，反应时间 4 h，反应温度 40°C。研究了 STG 的结构特征，如取代度（DS）、取代位置、重均摩尔质量（M）、单糖组成和链构象。通过 SEC-MALLS 得到了 M 的降低、Z-均回转半径（〈S〉）的增加和回转比容（SV）的增加。此外，还根据我们之前关于硫酸胡芦巴胶、瓜尔胶和刺槐豆胶的报告，对四种硫酸半乳甘露聚糖的结构性质进行了比较研究和分析。得出的结论是，较高的半乳糖支链可以增强空间位阻，这被推断为影响硫酸半乳甘露聚糖的取代度、M 和构象转变的重要因素之一。这项研究将为进一步研究半乳甘露聚糖家族的生物活性和医学应用提供有价值的信息。
