广叶绣球菌子实体细胞壁多糖特征及其体外激活Dectin-1受体活性

Characteristics and in Vitro Dectin-1 Receptor Activation Effect of Cell Wall Polysaccharides of Sparassis latifolia Fruiting body

广叶绣球菌(Sparassis latifolia)子实体水提残渣经超微粉碎、热水提取、20%~90%乙醇逐级沉淀获得8个细胞壁多糖组分(20E、30E、40E、50E、60E、70E、80E和90E),对其得率、多糖含量、β-葡聚糖含量、分子量分布特征、单糖组成、体外免疫活性进行测定。结果表明:广叶绣球菌水提残渣超微粉水提物得率为20.80%,其多糖含量为78.16%;水提物经乙醇逐级沉淀所得组分中,20E的得率最高,占提取物总量的27.16%,其多糖和β-葡聚糖含量分别为82.58%和35.54%;其余各组分得率和β-葡聚糖含量均较低,其中30E、40E、50E、60E这4个组分的多糖含量较高,均达到80%以上,而70E、80E、90E的多糖含量为26.36%~52.55%。利用高效凝胶尺寸排阻色谱多角度激光散射示差折光检测仪联用法(HPSEC-MALLS-RI)对20E、30E、40E、50E、60E的分析结果显示,20E主要含有2个峰,其重均分子量分别为1.47×10^7和5.06×10^6;30E、40E、50E和60E组分均主要含有1个均一对称峰,且随着醇沉浓度的增加,其重均分子量逐级减小。单糖组成分析结果显示:20E、30E、40E、50E、60E中的多糖均主要由葡萄糖组成,另外还含有少量半乳糖、岩藻糖和甘露糖,葡萄糖的摩尔百分比均超过80%。20E、30E、40E、50E、60E都具有体外激活Dectin-1受体的活性,其中20E的活性最高。

Water extraction processed residual fruiting bodies of Sparassis latifolia were ultra-pulverized,extracted with hot water in a 100℃water bath,and then treated by stepwise precipitation with 20%-90%ethanol to obtain eight fractions named 20E,30E,40E,50E,60E,70E,80E,and 90E,respectively.These fractions were measured for yield,polysaccharide andβ-glucan content,characteristics of molecular weight distribution,monosaccharide composition and in vitro immunological activity.The results showed that the yield and the polysaccharide content of the hot water extract of the residual fruiting bodies were 20.80%and 78.16%,respectively.Fraction 20E had a high yield,accounting for 27.16%of the total extract,and its polysaccharide andβ-glucan content were 82.58%and 35.54%,respectively.In contrast,the yield andβ-glucan content for the other fractions were low.The polysaccharide contents for fractions 30E,40E,50E,and 60E were over 80%,whereas the polysaccharide contents for fractions 70E,80E,and 90E were ranged between 26.36%and 52.55%.Using HPSEC-MALLS RI analysis,two peaks with weight average molecular weights of 1.47×10^7 and 5.06×106 were identified in 20E.Fractions 30E,40E,50E,and 60E exhibited a uniform symmetrical peak,and their weightaverage molecular weights were 4.16×10^6,2.46×10^6,7.19×10^5,and 1.08×10^5,respectively.The major monosaccharide in fractions 20E,30E,40E,50E,and 60E was glucose,accounting for over 80%of the total monosaccharaides in molar mass.A small amount of galactose,fucose and mannose were also detected in these fractions.Fractions 20E,30E,40E,50E,and 60E were able to activate the Dectin-1 receptor in vitro and 20E exhibited the highest potential.