Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biomedical Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.
Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biomedical Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.
J Chromatogr A. 2018 Apr 27;1547:29-36. doi: 10.1016/j.chroma.2018.03.006. Epub 2018 Mar 13.
Plant polysaccharides have numerous medicinal functions. Due to the differences in their origins, regions of production, and cultivation conditions, the quality and the functions of polysaccharides can vary significantly. They are macromolecules with large molecular weight (MW) and complex structure, and pose great challenge for the analytical technology used. Taking Dendrobium officinale (DO) from various origins and locations as model samples. In this investigation, mechanochemical extraction method was used to successfully extract polysaccharides from DO using water as solvent, the process is simple, fast (40 s) and with high yield. The MWs of the intact saccharides from calibration curve and light scattering measurement were determined and compared after separation with size exclusion chromatography (SEC). The large polysaccharide was acid hydrolyzed to oligosaccharides and the products were efficiently separated and identified using liquid chromatography coupled to a high resolution tandem mass spectrometry (LC-MS). Obvious differences were observed among LC-MS chromatograms of digested products, and the chemical structures for the products were proposed based on accurate mass values. More importantly, isomeric digested carbohydrate compounds were explored and characterized. All the chromatographic and mass spectrometric results in this study provided a multi-dimensional characterization, fingerprint analysis, and molecular structure level assessment of plant polysaccharides.
植物多糖具有多种药用功能。由于来源、产地和种植条件的不同，多糖的质量和功能有很大差异。它们是具有大分子量（MW）和复杂结构的大分子，对所用分析技术提出了巨大挑战。本研究以不同产地和来源的铁皮石斛（DO）为模型样品。采用机械化学提取方法，以水为溶剂，成功地从 DO 中提取了多糖，该过程简单、快速（40s）且产率高。通过尺寸排阻色谱（SEC）分离后，使用校准曲线和光散射测量法确定并比较了完整糖的 MW。将大多糖酸水解成低聚糖，并用高效液相色谱-高分辨串联质谱（LC-MS）对产物进行有效分离和鉴定。消化产物的 LC-MS 色谱图之间存在明显差异，并根据精确质量值提出了产物的化学结构。更重要的是，探索并表征了异构消化碳水化合物化合物。本研究中的所有色谱和质谱结果提供了植物多糖的多维特征分析、指纹分析和分子结构水平评估。
