冠县灵芝多糖的分离纯化、结构表征及抗氧化活性研究

Extraction,Purification,Structural Characterization and Antioxidant Activity of Polysaccharides from the Fruiting Body of Guanxian Ganoderma lucidum

以冠县灵芝为研究对象,采用传统浸提法获得水溶性灵芝多糖GLP,经Sevag法去蛋白及活性炭脱色,然后依次采用Capto TM DEAE离子柱层析和Superdex 6 prep Grad凝胶柱层析进行分离纯化,获得均一多糖GLPS80a,经高效凝胶色谱(HPGPC)法检测,其相对分子量为9024 Da,高效阴离子色谱(HPAEC)、红外光谱(FT-IR)和核磁共振(NMR)图谱分析结果表明,GLPS80a是由岩藻糖(Fuc)、氨基葡萄糖(GlcN)、半乳糖(Gal)、葡萄糖(Glc)、木糖(Xyl)、甘露糖(Man)和葡萄糖醛酸(GluA)等7种单糖组成,摩尔比为0.06:0.23:0.17:1.00:0.08:0.19:0.23,主要以β-D-(1,6)糖苷键连接的吡喃糖为主要组成且不含三股螺旋的酸性多糖。抗氧化结果表明,GLPS80a具有一定的DPPH自由基、OH自由基和ABTS+自由基的清除能力,它们的EC50分别为7.40、8.74和0.33 mg/mL,还原力RP0.5AU为8.33 mg/mL。本研究将为合理开发冠县灵芝资源和精深加工奠定理论基础。

Taking Ganoderma lucidum in Guanxian County as the experimental material,the crude polysaccharide GLP was extracted from the fruiting body of G.lucidum by hot water.After deproteinization by Sevag methods and decolorization by activated carbon methods,and then separation and purification by CaptoTM DEAE ion chromatography and Superdex 6 prep Grad gel chromatography,respectively,the homogeneous polysaccharide GLPS80a was obtained.And its average molecular weight was 9024 Da.Its chemical structure was preliminarly characterized by monosaccharide composition analysis,infrared scanning and nuclear magnetic resonance analysis,respectively.The results showed that GLPS80a was composed of fucose,glucosamine,galactose,glucose,xylose,mannose and gluconal,and the molar percentage was 0.06:0.23:0.17:1.00:0.08:0.19:0.23.It was an acid polysaccharide with the main of pyranoid glucose linked byβ-D-(1,6)glycosidic bond and did not have a triple helix structure.The antioxidant results indicated that GLPS80a had scavenging ability of DPPH radical,·OH radical and ABTS^(+)radical.Their EC50 was 7.40,8.74 and 0.33 mg/mL,respectively,and the reducing power RP0.5AU was 8.33 mg/mL.This work would lay a theoretical foundation for development of G.lucidum resources in Guanxian County.