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–MS²). Obvious differences were observed among LC–MS² 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.

植物多糖具有许多药用功能。由于其来源，生产地区和培养条件的差异，多糖的质量和功能可能会有很大差异。它们是具有大分子量（MW）和复杂结构的大分子，对所用的分析技术提出了巨大的挑战。服用石end（DO）来自不同来源和位置的模型样本。本研究采用机械化学提取方法，以水为溶剂，成功地从溶解氧中提取多糖，工艺简单，快速（40 s），收率高。根据校准曲线和光散射测量结果确定完整糖的分子量，并与尺寸排阻色谱法（SEC）分离后进行比较。大型多糖被酸水解为寡糖，并使用液相色谱与高分辨率串联质谱（LC-MS ²）进行高效分离和鉴定产物。LC–MS ²之间观察到明显差异根据准确的质量值，提出了消化产物的色谱图，以及产物的化学结构。更重要的是，对异构消化的碳水化合物化合物进行了研究和表征。本研究中的所有色谱和质谱分析结果均提供了植物多糖的多维表征，指纹分析和分子结构水平评估。