基质辅助激光解析电离飞行时间质谱法测定大蒜寡糖和多糖分子质量分布

研究大蒜多糖的分子质量分布，探索获得适宜于结构研究的不同分子质量分布的大蒜多糖样品的方法。利用不同体积量的丙酮和乙醇为沉淀剂，得到一系列不同分子质量的大蒜多糖样品，并利用基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MS)法测定各样品的分子质量分布。结果表明，不同体积量的丙酮与乙醇分解沉淀所获得的样品中都含有低聚糖和多糖，糖的分子质量分布在362～2811u 之间；丙酮对大蒜多糖的沉淀能力比乙醇好，3 倍体积丙酮的多糖提取液所获得样品中低聚糖的含量高于4 倍体积的乙醇。因此，通过调整丙酮或乙醇的的比例可得到不同分子质量分布的大蒜寡糖、多糖。

Determination of Molecular Weight Distribution of Garlic Oligosaccharide and Polysaccharide by Matrix-assisted Laser Desorption/Ionization Mass Spectrometry

A series of garlic oligosaccharide and polysaccharide samples were prepared by precipitation with varying volumes of acetone or ethanol,and their molecular weight distributions were determined by matrix assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF-MS).Three-fold volume of acetone could pre-cipitate more oligosaccharide and polysaccharide than 4-fold volume of ethanol.The molecular weight distribution of oligosaccharide and polysaccharide was from 362 to 2811 u,and can be a...