GC-MS联合二维核磁对文蛤多糖Fr.2A组分结构的解析

摘要

采用GC-MS联合二维核磁的方法,对文蛤均多糖结构进行解析.运用双酶辅助水提的方法,提取文蛤粗多糖(MMPX),分离纯化得到文蛤均多糖,并通过气质联用技术(GC-MS)和核磁共振波谱(1D,2D NMR),对文蛤均多糖的结构进行了分析.结果表明,从文蛤中提取得到文蛤粗多糖(MMPX),经分离纯化得到高纯度文蛤均多糖Fr.2A,其单糖组成为葡萄糖(Glc). GC-MS分析发现,Fr.2A存在三种残基单元1,4-Glcp、T-Glcp和l,4,6-Glcp,摩尔比为5.58∶1.26∶1.0;核磁共振波谱分析表明,Fr.2A是以α-(1→4)与少量α-(1→6)连接为主链,并存在少量的α-(1→6)和β-(1→4)支链的新型水溶性D型吡喃葡聚糖.%In this study,the structure of a polysaccharide is analyzed using GC-MS combined with two-dimensional NMR.A polysaccharide from the clam Meretrix meretrix Linnaeus (MMPX) was prepared using double enzymeassisted water extraction,and its purity was analyzed and characterized using GC-MS and 1D and 2D NMR.The result showed that Fr.2A,extracted and purified from M.meretrix Linnaeus,is a type of highly purified polysaccharide.The GC-MS analysis demonstrated that Fr.2A had three types of residue:1,4-Glc),T-Glc),and (1,4,6-Glc,and that the molar ratio of these residues was 5.58 ∶ 1.26 ∶ 1.0.The NMR spectrum results demonstrated that the main chain in Fr.2A was α-(1→4) with a small amount of α-(1→6) included,and that the branch was linked with less α-(1→6) and β-(1→4),which is a novel water-soluble D-glucan.