一种新的多糖——链霉菌多糖的分离与结构确证

Isolation and structural analysis of a new polysaccharid, streptomyces polysaccharide

目的从链霉菌发酵液中分离纯化出一种新的多糖———链霉菌多糖(streptomyces polysaccharide,SMP),并进行结构确证。方法采用乙醇沉淀多糖类大分子物质、Sevage法去蛋白、DEAE-纤维素离子交换层析法及Sephadex G-25凝胶过滤法纯化多糖。其结构经HPLC、UV、IR、1H-NMR以及高碘酸氧化、Smith降解等方法进行测定。结果分离纯化出的多糖属于中性多糖,相对分子质量约为4855 道尔顿;单糖组成以葡萄糖为主,含有少量果糖,二者的摩尔比约为22:1(10.96∶0.48);糖苷键的链接方式为(1→6)—α—D—吡喃型;命名为SMP。结论从链霉菌发酵液中分离纯化出的多糖SMP是以1→6位键合的α—D—吡喃型多糖。

Objective To isolate and purify a new polysaccharid Streptomyces polysaccharid polysaccharide (SMP ), from cultured broth of a Streptomyces sp.strain and perform its structural analysis. Methods Ethanol was used to precipitate the polysaccharides and macromolecules from the broth. The proteins in the precipitate were removed by Sevage method and purification of SMP was carried out by DEAE-celluloseion-exchange chromatography and Sephadex G-25 gel filtration. The chemical structure of the SMP was determined by combined application of high performance liquid chromatography (HPLC), UV, IR and 1H-NMR spectroscopy, supplemented by periodate oxidation and Smith degradation. Results The purified SMP was neutral by a relative molecular mass of approximately 4 855. Sugar analysis showed that SMP contained glucose and fructose residues in an approximate molar ratio of 22:1 (10.96 to 0.48). The glycosidic linkages were estimated to be (1→6)- α-D- pyranoside form. Conclusion SMP is characterized as a (1→6)- α-D- pyranose.