南极树粉孢属真菌胞外多糖的分离纯化及结构表征

Isolation,Purification and Structural Elucidation of the Exopolysaccharides from Antarctic Fungus Oidiodendron truncatum

研究南极树粉孢属(Oidiodendron truncatum)真菌所产胞外多糖的理化性质和结构特征。采用阴离子交换柱层析和凝胶柱层析对南极树粉孢属(Oidiodendron truncatum)真菌胞外多糖进行了系统的分离纯化,从中得到4个均一的组分(AFW1,AFW2,AFS1和AFS2),并结合红外、气质及核磁等技术对它们的结构进行了解析。结果表明:AFW1和AFW2为中性多糖,AFS1和AFS2中含有少量的蛋白;AFW1和AFS1是由甘露糖、葡萄糖和半乳糖3种单糖组成的结构复杂的杂多糖;AFW2和AFS2则仅由葡萄糖组成,其中AFW2属线性(-1,6-葡聚糖,而AFS2属于C-3位有分支的α-1,6-葡聚糖。

The crude exopolysaccharides isolated from Antarctic fungus Oidiodendron truncatum by ethanol precipitation were fractionalized into four fractions（AFW1,AFW2,AFS1 and AFS2） by Q Sepharose F.F.and Sephadex G 150 columns.Their physiochemical properties and structural characteristics were studied by chemical analysis together with infrared spectra,GC-MS and NMR.Composition analysis showed that AFW1 and AFW2 were neutral polysaccharides,while AFS1 and AFS2 contained some protein.Structural analysis indicated that AFW1 and AFS1 were heteropolysaccharides with mannose,glucose and galactose,whereas AFW2 and AFS2 were homopolysaccharides with glucose.AFW2 and AFS2 belong to the Dextran family,the difference was that AFW2 had a linear linkage pattern,while AFS2 had branch at the C-3 position of α-D-（1→6）-linked glucopyranose.