An acidic extracellular polysaccharide(EPS)was gained from Stropharia rugosoannulata fermentation broth by the alcohol precipitate method.Sulfated derivative of EPS(S-EPS)was gained by chlorosulfonic acid-pyridine met...An acidic extracellular polysaccharide(EPS)was gained from Stropharia rugosoannulata fermentation broth by the alcohol precipitate method.Sulfated derivative of EPS(S-EPS)was gained by chlorosulfonic acid-pyridine method and the conditions were as follows:pyridine as the reaction solvent,temperature 80°C,and reaction time 90 min.The chemical structure and chain conformation of EPS and S-EPS were characterized by FT-IR,NMR and size exclusion chromatography(SEC)coupled with multi-angle laser light scattering(MALLS)detection.FT-IR spectra indicated the sulfated group was linked to the polymer.The EPS mainly consists of mannose,glucose and glucuronic acid,and the glycosidic bond type is mainly(1→4)-linked and(1→6)-linked.C6 and C2 were substituted by sulfate groups.The EPS was degraded into smaller molecular weight(Mw)polysaccharides with the larger molecular size(Rg)after sulfation and S-EPS has better hydrophilicity.Moreover,the sulfated derivative S-EPS was found to have a better scavenging ability on hydroxyl radicals than EPS.It proved that the chemical modification of S.rugosoannulata polysaccharides by sulfation effectively enhanced their antioxidant activity.展开更多
基金We gratefully acknowledge the financial supports from the Program for Innovative Research Team(in Science and Technology)at the University of Henan Province(20IRTSTHN022)Major Public Welfare Projects in Henan Province(201300110200).
文摘An acidic extracellular polysaccharide(EPS)was gained from Stropharia rugosoannulata fermentation broth by the alcohol precipitate method.Sulfated derivative of EPS(S-EPS)was gained by chlorosulfonic acid-pyridine method and the conditions were as follows:pyridine as the reaction solvent,temperature 80°C,and reaction time 90 min.The chemical structure and chain conformation of EPS and S-EPS were characterized by FT-IR,NMR and size exclusion chromatography(SEC)coupled with multi-angle laser light scattering(MALLS)detection.FT-IR spectra indicated the sulfated group was linked to the polymer.The EPS mainly consists of mannose,glucose and glucuronic acid,and the glycosidic bond type is mainly(1→4)-linked and(1→6)-linked.C6 and C2 were substituted by sulfate groups.The EPS was degraded into smaller molecular weight(Mw)polysaccharides with the larger molecular size(Rg)after sulfation and S-EPS has better hydrophilicity.Moreover,the sulfated derivative S-EPS was found to have a better scavenging ability on hydroxyl radicals than EPS.It proved that the chemical modification of S.rugosoannulata polysaccharides by sulfation effectively enhanced their antioxidant activity.
文摘为了探讨大球盖菇多糖碱法提取最佳工艺条件,为大球盖菇多糖的综合开发利用提供参考依据。采用100目菇粉碱液浸提方法,进行碱液浓度（p H）、液料比（m L/g）、温度（℃）和提取时间（min）的单因素试验和四因素三水平[L_9（3^4）]的正交试验,用硫酸苯酚方法测定提取的多糖并计算得率。结果表明：4种因素对大球盖菇多糖提取的影响程度强弱顺序为p H影响最大,时间次之,温度再次之,液料比影响最小。p H 9,提取时间为60 min,温度为80℃,液料比为60 m L/g的组合是大球盖菇多糖提取的最佳条件,大球盖菇多糖的提取得率最高达8.12%。碱法提取是大球盖菇多糖较好的提取方法。该提取工艺条件简单、稳定、可行。
