可溶性固形物含量对制备猴头菇子实体多糖的理化性质及免疫活性的影响

Effect of Soluble Solid Levels in Aqueous Extracts of Hericium erinaceus Fruit Bodies on the Physicochemical Properties and Immunological Activity of Ethanol Precipitated Polysaccharide

调节猴头菇(Hericium erinaceus)浓缩液中可溶性固形物含量分别至2.5、18.5和35°Brix,经20%、50%、70%乙醇分级醇沉,得到9个猴头粗多糖样品,依浓缩液中可溶性固形物含量由低到高依次命名为20-1、20-2、20-3,50-1、50-2、50-3,70-1、70-2、70-3,用HPSEC-MALLS-RI和离子色谱分析其分子量分布和单糖组成,并研究了其体外刺激巨噬细胞释放NO的活性。结果表明,相同醇沉浓度下,随浓缩液中可溶性固形物含量的升高,得到的粗提物得率升高、但其中多糖含量呈降低趋势。可溶性固形物含量显著影响醇沉多糖的分子量分布、单糖组成及其摩尔比。在相同醇沉浓度下,随着浓缩液中可溶性固形物含量的降低,大分子量多糖所占比例显著增大。20%醇沉多糖刺激巨噬细胞释放NO的活性较50%和70%醇沉的多糖高,且随着浓缩液中可溶性固形物含量的升高醇沉多糖的活性呈降低趋势。

Hericium erinaceus fruit bodies （500 g fresh weight,water content 90%）were extracted for 2 h with 1.5 volumes of double-distilled water （100 ℃）and,after filtration,rotary evaporation was used to obtain solutions containing different concentrations of soluble solids （2.5,18.5 and 35°Brix）.Nine crude polysaccharide fractions （20-1,20-2,20-3,50-1,50-2,50-3,70-1,70-2 and 70-3）were then obtained by precipitation with 20%,50% and 70% ethanol,respectively.Crude polysaccharide yields increased,and the polysaccharide content of the crude extracts decreased,with increasing soluble solid concentrations prior to ethanol precipitation. High-performance size-exclusion chromatography linked to multi-angle laser light scattering and refractive index detectors （HPSEC-MALLS-RI）,and monosaccharide analysis,revealed that the soluble solid concentration of the aqueous extracts significantly affected the molecular distribution patterns,and the molar ratios of the monosaccharide components,of the precipitated polysaccharides. Lower soluble solid levels resulted in a significantly increased proportion of high molecular weight material in the crude polysaccharide precipitated with the same ethanol concentration.Crude polysaccharide precipitated with 20% ethanol was more effective in stimulating macrophages to release NO compared with material precipitated with 50% and 70% ethanol,and the stimulatory effect decreased with increasing soluble solid concentrations in the aqueous extracts before precipitation.