【作者】 郝强；

【导师】 刘晓宇；

【作者基本信息】 华中农业大学 ， 食品科学， 2008， 硕士

【摘要】 香菇是一种集营养、保健和药用功效于一体的可直接利用的药食两用菌类,广泛的分布于我国各省。香菇中含多种有效药用成分,尤其含有一种非特异免疫刺激剂（具有抗病毒、抗肿瘤、降血糖等生物活性的香菇多糖）。并且在临床上得到广泛应用。本文以香菇柄为原料,首次采用酸为提取剂对香菇中水溶性多糖进行提取、分离、纯化、结构的初步鉴定、生物活性的研究。实验具体分为以下几部分:1.采用酸浸提法提取香菇多糖,以酸浓度、料液比、浸提时间、浸提温度和加醇比为影响因素,通过五元二次回归通用旋转组合设计,确定出优化的主要工艺条件是:酸浓度0.16-0.23 mol/L、料液比1:36-1:49、浸提时间2.7h-3.8h、浸提温度50℃-67.8℃、加醇比1:2-1:3,4℃醇沉24h。浸提1次提取多糖得率为7.61%,浸提2次提取多糖得率可达13.56%。2.研究了香菇多糖的分离纯化方法,并进行纯度鉴定。采用鞣酸法脱除游离蛋白,双氧水脱色,得到初步纯化的多糖。再经过乙醇梯度分级,得到三种级分多糖SP₁、SP₂、SP₃得率分别为25.58%、64.77%、9.64%。通过冻融离心,Sephadex G-100柱层析检验,香菇多糖SP₂为相对均一多糖。且中性糖含量为56.79%,糖醛酸含量为28.11%,蛋白质含量为1.20%。3.对香菇多糖SP₂结构进行了初步研究,采用凝胶色谱法（GPC）测定香菇多糖SP₂分子量,重均分子量为5.203×10⁴Da;通过气相色谱检测香菇多糖SP₂的单糖组成,其香菇多糖SP₂的单糖组成为葡萄糖、甘露糖和半乳糖,并以葡萄糖为主;红外扫描的结果表明香菇多糖SP₂具有D-吡喃葡萄糖构型;4.采用化学发光法考察香菇多糖SP和SP₂的抗氧化活性,结果表明香菇多糖SP和SP₂都具有清除超氧阴离子、羟基自由基、过氧化氢的能力。通过化学模拟体系体外和体内抗氧化试验表明,香菇多糖SP和SP₂具有抑制小鼠红细胞溶血,抑制小鼠肝组织匀浆MDA的生成和肝线粒体肿胀度的作用。更多还原

【Abstract】 Lentinuns,widely spread in our country,is one kind of nutritious,healthy and therapeutic fungus,combining both medical and edible characteristic.It contains numerous therapeutic compounds,particular a substance,named non-immune stimulus.It has various bioactivities proved by the clinic trials,such as anti-virus,anti-tumour and declining the sugar content in the blood,etc.This research utilized the stem of lentinuns as the raw materials and the acid as the solvent,to extract the polysaccharide and identify the interaction of separation, purification and configuration.Meanwhile the research studied its bioactivity and chemical modification.The experiment included following sectors.1.Extracted the lentinuns polysaccharide with acid,setting the acid ratio, materials/acid solvent ratio,immersion time,immersion temperature and ethanol additional content as the main factors,though modular design between quadratic regression and positive rotation,reached the conclusion that the optimum process,the ratio of acid, 0.16-0.23mol/L,materials/acid solvent ratio,1:36-1:49,immersion extraction time 2.7-3.8h,immersion extraction temperature 50℃-67.8℃,and the ethanol ratio was 1:2-1:3,at 4℃,24h.The first gain ratio was 7.61%,and second time was 3.56%.2.Studyed on the method of separation and purification of lentinuns polysaccharide, and identified the concentration.The polysaccharide was rinsed by tannin acid and H₂O₂, to remove the free protein and color.After the procedures mentioned,we got the primal purified polysaccharide.Then the sample was rinsed by gradient ethanol,and three different level polysaccharide were obtained,named SP₁,SP₂,SP₃,25.58%,64.77%,9.64%, respectively.The SP₂ whose content of Uronic acid and protein was 28.11%,1.20%.This portion was sole purified polysaccharide after it was identified though the method of frozen centrifugation,Sephadex G-100 Gel Permeation chromatography.3.Detected the configuration of SP₂ primally.The molecular weight of SP₂,average 5.203×10⁴Da,was deterred by GPC.After the GC examined the composition of SP₂,we could find that SP₂ contained several monosaccharide,and major portion was glucose,others wasMannose and Galactose.The infrared scanning results demonstrated that SP₂,configuration was typical D-Glucopyranosyl.4.Inspected the capability of anti-oxidation though the method of chemical radiation,and the results demonstrated that SP and SP₂ had the capability of scavenging O₂-·,radical OH·,H₂O₂.It showed that SP and SP₂ had the capability of inhibiting the hemolysis of mouse’s red cell and forming of MDA located in the mice’s liver’s slurry and swelling degree of Mitochondria in the liver,by the means of stimulating In vitro systems by chemical approach,and anti-oxidization reaction in vivo.更多还原