Zou Yuan-Feng, Zhang Bing-Zhao, Inngjerdingen Kari Tvete, Barsett Hilde, Diallo Drissa, Michaelsen Terje Einar, Paulsen Berit Smestad
Department of Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, P. O. Box 1068 Blindern, 0316 Oslo, Norway.
Department of Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, P. O. Box 1068 Blindern, 0316 Oslo, Norway; GIAT-HKU joint Center for Synthetic Biology Engineering Research (CSynBER), Guangzhou Institute of Advanced Technology, Chinese Academy of Sciences, Nansha, Guangzhou 511458, PR China.
J Ethnopharmacol. 2014 Aug 8;155(1):672-8. doi: 10.1016/j.jep.2014.06.017. Epub 2014 Jun 13.
Water decoctions of the root bark, stem bark and leaves of Terminalia macroptera are used by traditional healers in Mali to cure a wide range of illnesses, such as wounds, hepatitis, malaria, fever, cough and diarrhea as well as tuberculosis. Plant polysaccharides isolated from crude water extracts have previously shown effects related to the immune system. The aims of this study are comparing the properties of the polysaccharides among different plant parts, as well as relationship between chemical characteristics and complement fixation activities when the plant material has been extracted as the traditional healers do, with boiling water directly.
Root bark, stem bark and leaves of Terminalia macroptera were extracted by boiling water, and five purified polysaccharide fractions were obtained by anion exchange chromatography and gel filtration. Chemical compositions were determined by GC of the TMS derivatives of the methyl-glycosides and the linkage determined after permethylation and GC-MS of the derived partly methylated alditol acetates. The bioactivity was determined by the complement fixation assay of the crude extracts and purified fractions.
The acidic fraction TRBD-I-I isolated from the root bark was the most active of the fractions isolated. Structural studies showed that all purified fractions are of pectic nature, containing rhamnogalacturonan type I backbone. Arabinogalactan type II side chains were present in all fractions except TRBD-I-II. The observed differences in complement fixation activities among the five purified polysaccharide fractions are probably due to differences in monosaccharide compositions, linkage types and molecular sizes.
The crude extracts from root bark and stem bark have similar total activities, both higher than those from leaves. The root bark, leaves and stem bark are all good sources for fractions containing bioactive polysaccharides. But due to sustainability, it is prefer to use leaves rather than the other two plant parts, and then the dosage by weight must be higher when using leaves.
在马里，传统治疗师使用大翅榄仁树的根皮、茎皮和叶子的水煎剂来治疗多种疾病，如伤口、肝炎、疟疾、发烧、咳嗽、腹泻以及肺结核。先前从粗水提取物中分离出的植物多糖已显示出与免疫系统相关的作用。本研究的目的是比较不同植物部位多糖的性质，以及当按照传统治疗师的方法直接用沸水提取植物材料时，化学特征与补体固定活性之间的关系。
用沸水提取大翅榄仁树的根皮、茎皮和叶子，通过阴离子交换色谱和凝胶过滤获得五个纯化的多糖级分。通过甲基糖苷的TMS衍生物的气相色谱法测定化学组成，并在全甲基化后通过衍生的部分甲基化糖醇乙酸酯的气相色谱 - 质谱法测定连接方式。通过粗提取物和纯化级分的补体固定试验测定生物活性。
从根皮中分离出的酸性级分TRBD - I - I是所分离级分中活性最高的。结构研究表明，所有纯化级分均具有果胶性质，含有I型鼠李半乳糖醛酸聚糖主链。除TRBD - I - II外，所有级分中均存在II型阿拉伯半乳聚糖侧链。五个纯化多糖级分之间观察到的补体固定活性差异可能是由于单糖组成、连接类型和分子大小的差异。
根皮和茎皮的粗提取物具有相似的总活性，均高于叶提取物。根皮、叶和茎皮都是含有生物活性多糖级分的良好来源。但出于可持续性考虑，优先使用叶子而非其他两个植物部位，并且使用叶子时按重量计的剂量必须更高。
