淡紫拟青霉胞外多糖的分离、纯化及结构分析

Isolation, purification and structure analysis of polysaccharides from Peacilomyces lilacinus

摘要:

淡紫拟青霉NH-PL-03菌株的胞外多糖粗提物对枯萎病病原菌-尖孢镰刀菌具有较好的抑制效果，文中对淡紫拟青霉胞外多糖进行了分离纯化和结构分析，以期为其构效关系研究奠定基础。采用乙醇沉淀法从淡紫拟青霉发酵液中提取粗多糖，经Sevage法脱蛋白后，过Superdex-G75凝胶层析柱分离得到胞外多糖EP-1。紫外分光法和Sephacryl S-200 HR凝胶层析柱检测EP-1为均一多糖，Sephacryl S-200柱层析测得EP-1的分子量为35.2 kDa，完全酸水解后纸层析检测EP-1的单糖组成中仅有葡萄糖，红外光谱、高碘酸氧化和Smith降解结果表明EP-1的化学结构是以β-(1,3)糖苷键连接而成的无分枝的葡聚糖。刚果红络合试验表明EP-1在稀的碱溶液中以3股螺旋构象存在。

Abstract:

The paper dealt with the characterization of polysaccharide of Paecilomyces lilacinus NH-PL-03 strain. First, we extracted and purified exude polysaccharide from the fungal fermentation broth by ethanol depositing method. Second, the proteins were removed by the Sevage method from the crude polysaccharide. Third, the purified polysaccharide (EP-1) was obtained after Superdex G-75 column separation. The results of UV-spectrometer and Sephacryl S-200 HR chromatography experiments showed that the EP-1 was a homogeneous pure polysaccharide with molecular weight of 35.2 kDa. Tested by paper chromatography analysis using the complete hydrolysis by sulfuric acid, we found that the EP-1 comprise single component as glucose. The chemical structure of EP-1 was confirmed as a kind of linear glucan linked by β-(1,3) linkage. The Congo red reaction performed that EP-1 probable presented a triple-helica conformation in the dilute alkali.