桔梗多糖提取、分离纯化以及生物活性研究

Study on Extraction,Isolation,Purification and Biological Activity of Polysaccharides from Platycodon grandiflorum

本研究以桔梗为原料,研究了桔梗多糖的分离、纯化和体内抗氧化性,采用水提醇沉、脱蛋白脱色、Sephadex G-25和Sephadex G-100分离纯化桔梗多糖,以抗坏血酸作为阳性对照,采用邻二氮菲法、ABTS＋自由基清除、铁还原性、·OH自由基清除法和1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）研究粗多糖和纯化后的多糖的体外抗氧化性。结果表明：纯多糖和粗多糖都具有较好的抗氧化效果,纯多糖在ABTS＋、·OH和DPPH自由基清除性能上要优于粗多糖,还原性和铁离子螯合活性略低于粗多糖,样品的抗氧化能力与样品的浓度呈正相关。本研究表明桔梗纯多糖是天然的抗氧化剂的潜在资源,为桔梗多糖功能性食品的开发提供了理论依据。

Platycodon grandiflorus was used as the raw material in this research to study the extraction,isolation,purification and resistance to oxidation in vitro of polysaccharide from platycodon grandiflorum.The isolation and purification of polysaccharides from platycodon grandiflorum was performed by water extraction and alcohol precipitation,deprotein and decolorization,Sephadex G-25 and Sephadex G-100.Using ascorbic acid as positive control,the antioxidant activities of crude polysaccharide and purified polysaccharides were studied by phenanthroline method,ABTS＋ radical scavenging method,iron reducibility,·OH free radical scavenging method and 1,1-diphenyl-2-picrylhydrazyl,DPPH.The results showed that both pure polysaccharide（PP） and crude polysacchari（CP） had good antioxidant activities.PP had stronger scavenging effects on ABTS＋,·OH and DPPH than CP,but lower in reducing power and iron ion chelating activity.Moreover,the antioxidant capacity of the sample was positively correlated with the concentration of the sample..This study showed that the PP from Platycodon grandiflorum were a potential resource for natural antioxidants,which could provide the theoretical basis for the development of platycodon grandiflorum functional food.