杏鲍菇多糖的超滤分离及其理化特性和生物活性分析

Physicochemical Analysis and Bioactivity Investigation of Polysaccharides Separated from Pleurotus eryngii by Ultrafiltration

采用超滤法将杏鲍菇下脚料水提物分为不同相对分子质量范围3个部分,并对各部分样品的得率、总糖和β-葡聚糖质量分数、相对分子质量分布、单糖组成及其对巨噬细胞释放NO的影响进行了考察。结果表明,PU1得率远高于PU10和PU100,为14.6%,其总糖质量分数最高,达到62.75%。PU10和PU100中的β-葡聚糖质量分数较高,分别为18.38%和19.91%,在总糖中所占比例超过50%。相对分子质量分析结果表明,粗多糖可以按照超滤膜的截留范围实现较好的分离,且PU100和PU10均含有多个组分,其中PU100中重均相对分子质量>100 000组分约占73%,PU10中两个组分的相对分子质量均超过10 000;而PU1主要含有一个组分,其重均相对分子质量为1 110×10~3。超滤各部分样品中的多糖分别由4~7种单糖组成,但种类及摩尔分数具有较大差异。活性测试结果显示,超滤所得各样品均具有体外刺激巨噬细胞释放NO的活性,在低质量浓度(50μg/m L)时PU100活性最高。

Three different molecular weight fractions, i.e., 100 kD （PU100）, 10 kD-100 kD （PU 10） and 1-10 kD （PUI）, were separated from the extracts of Pleurotus eryngii leftover in hot water （100 ℃ ） by membrane ultrafiltration. The physicochemical characteristics of fractions in the extracts were characterized including the product yield,the content of total sugar and β -glucan,the distribution of molecular weight,the composition of monosaccharide and its effects on the NO release from macrophages. PU l showed the highest yield of 14.6% ,which was much higher than that of either PU10 or PU100. The [3-glucan （over 50% of β-glucan） contents of PU10 and PU100 were 18.38% and 19.91% ,respectively. The crude polysaccharide could be efficiently separated by ultrafiltration membrane within the range of molecular weight as HPSEC analysis suggested. There were several fractions in both PU100 and PU 10. Around 73% of PU100 was the polysaccharides with molecular weight 〉100 kD,while the molecular weights of two components in PU10 were larger than I0 kD and the main component in PUI was 1.11 kD. Monosaccharide composition analysis indicated 4 and 7 monosaccharides composed the polysaccharides in different fi＇actions with significant differences in types and molar ratios of monosaccharide. The activity of stimulating RAW264.7 macrophages to release nitric oxide （NO） was observed for all of the ultrafiltration fractions,among which PUI00 represented the highest activity at low concentration （50 μg/mL）.