【作者】 聂凌鸿；

【导师】 宁正祥；

【作者基本信息】 华南理工大学 ， 食品科学， 2004， 博士

【摘要】 本文以淮山（Dioscorea fordii Prain et Burkill）为原料,对淮山多糖的提取、分离纯化、纯度鉴定、理化性质、结构分析、化学修饰、生物活性等方面进行了较为系统的研究,得到如下结论: 1.依次采用热水和碱液提取淮山多糖,所得多糖总得率为0.53%;淮山水溶性多糖适宜提取条件为料液比1:8（w:v）、浸提温度45℃、浸提时间2h,在此条件下淮山水溶性多糖的得率为0.28%。淮山碱溶性多糖适宜提取条件为料液比1:8（w:v）,NaOH 浓度0.3mol/L,浸提时间1h,乙醇浓度80%,在此条件下淮山碱溶性多糖的得率为0.25%。2.采用超声波法可使淮山水溶性多糖得率比热水浸提法提高0.08%,超声波处理条件为:频率20-25KHz,功率100w,每次10s,间隔10s,超声波输出总时间30min。采用超声波法可使淮山碱溶性多糖得率比碱提法提高0.04%,超声波处理条件为:频率20-25KHz,功率80w,每次2s,间隔5s,超声波输出总时间10min。3.淮山经热水浸提、乙醇沉淀,得到淮山水溶性多糖粗品（DFPNC）,经分离纯化得到纯度为99.3%的淮山水溶性多糖DFPN-Ⅰ;DFPN-Ⅰ的比旋光度为+42.3,分子量为48200Dal,总糖含量为99.3 %,组成单糖为葡萄糖、甘露糖和半乳糖,组成单糖摩尔比为1∶1.26∶2.87,键型构成为1→4 键、1→6 键、1→2 键,键型比例为84.3∶9.0∶6.7,IR 谱图和1H-NMR 谱图分析表明其组成单糖为β-吡喃糖。4.淮山经热水浸提后的残渣,再经碱液浸提、乙醇沉淀得到淮山碱溶性多糖粗品（DFPAC）,经分离纯化得到纯度为99.1%的淮山碱溶性多糖DFPA-Ⅰ;DFPA-Ⅰ比旋光度为+128.4,分子量为64500Dal,总糖含量为99.1 %（其中糖醛酸含量为21.7 %）,组成单糖为葡萄糖、甘露糖、半乳糖、半乳糖醛酸,组成单糖摩尔比为1∶2.18∶3.39∶1.82,键型构成为1→3 键、1→2 键、1→6 键,键型比例为68.4∶25.5∶6.1,IR 谱图和1^H-NMR 谱图分析表明表明其组成单糖为α-吡喃糖。5.对淮山碱溶性多糖DFPA-Ⅰ进行了化学改性。所得产物羧甲基化DFPA-Ⅰ取代度为0.55,在水中溶解度为34mg/mL,是DFPA-Ⅰ在水中溶解度的17 倍,对重金属Hg²⁺的吸附率是DFPA-Ⅰ的4.6 倍。所得产物硫酸酯化DFPA-Ⅰ取代度为1.06,在水中的溶解度为41mg/mL,是DFPA-Ⅰ在水中溶解度的20.5 倍,硫酸化DFPA-Ⅰ对超氧阴离子自由基的清除作用是DFPA-Ⅰ的4 倍。更多还原

【Abstract】 In this dissertation,the author conducted a series of study on Dioscorea fordii Prain et Burkill polysaccharides,which were isolated and purified from Dioscorea fordii Prain et Burkill,and their phsico-chemical characteristics and chemical structure were determined with instruments analysis technique and chemical modification technique of biomacromolecule,and their antioxidation and hypoglycemic activity were investigated with medical analysis technique and biological active analysis technique .The following results were achieved. 1.Polysaccharides of D. fordii Prain et Burkill were extracted by hot water and its residue extracted by alkali.The gross extracting ratio of polysaccharides of D. fordii Prain et Burkill was 0.53%.The optimal extracting conditions of water soluble polysaccharides from D. fordii Prain et Burkill are as follows: the adding ratio of water is 1:8,the temperature of extraction is 45℃,the time of extraction is 2 hours,The extracting ratio of water soluble polysaccharides from D. fordii Prain et Burkill were 0.28%.The optimal extracting conditions of alkali extractional polysaccharide from D. fordii Prain et Burkill are as follows: the adding ratio of alkali is 1:8, the concentration of NaOH is 0.3moL/L,the time of extraction is 1 hour, the concentration of ethanol is 80%. The extracting ratio of alkali soluble polysaccharides from D. fordii Prain et Burkill were 0.25%. 2.The extracting ratio of water soluble polysaccharides from D. fordii prain et burkill by ultrasonic method is 0.08% higher than that of extracted by hot water extracting method.The ultrasonic process conditions on extracting water solube polysaccharides of D. fordii Prain et Burkill as fowllows:ultrasonic frequency is 20-25KHz ,out put power is 100w,maintain 10 seconds and interval 10 seconds at one time,gross ultrasonic action time is 30 minutes.The extracting ratio of water soluble polysaccharides from D. fordii prain et burkill by ultrasonic method is 0.04% higher than that of extracted by alkali extracting method. The ultrasonic process conditions on extracting alkali solube polysaccharides of D. fordii Prain et Burkill as fowllows:ultrasonic frequency is 20-25KHz with ultrasonic generator,out put power is 80w,maintain 2 seconds and interval 5 seconds at one time,gross ultrasonic action time is 10 minutes. 3.The crude water soluble polysaccharides of D. fordii Prain et Burkill were extracted by hot water and precipitated by adding ethanol,through isolation and purified gained pure water soluble polysaccharides DFPN-Ⅰ,and the pure degree of water soluble polysaccharide DFPN-Ⅰis 99.3%.The specific rotatory of DFPN-Ⅰis +42.3,the average molecular weight of DFPN-Ⅰis 48200Dal,the total sugar content is 99.3%.The unit monosaccharide of DFPN-Ⅰwas identified as glucose,mannose,galactose with a ratio of 1∶1.26∶2.87 ,the sugar chain of DFPN-Ⅰis composed of 1→4 linked, 1→6 linked,and 1→2 linked in a ratio of 84.3∶9.0∶6.7.Infrared spectrum and 1~H-NMR spectrum of DFPN-Ⅰresults showed that monosaccharide of DFPN-Ⅰwere all β-pyranose. 4.The residue extracted by hot water were extracted by alkali,the crude alkali soluble polysaccharides of D. fordii Prain et Burkill were extracted by alkali and precipitated by adding ethanol, through isolation and purified gained pure alkali soluble polysaccharide DFPA-Ⅰ,and the pure degree of water soluble polysaccharide DFPA-Ⅰis 99.1%.The specific rotatory of DFPA-Ⅰis +128.4,the average molecular weight of DFPA-Ⅰis 64500Dal,the total sugar content is 99.1%,and the uronic acid is 21.7%. The unit monosaccharide of DFPA-Ⅰwas identified as glucose, mannose,galactose and galactose uronic acid with a rate of 1∶2.18∶3.39∶1.82. and the sugar chain of DFPA-Ⅰis composed of 1→3 linked, 1→2 linked,and 1→6 linked in a ratio of 84.3∶9.0∶6.7. Infrared spectrum and 1H-NMR spectrum of DFPA-Ⅰresults showed that monosaccharide of DFPA-Ⅰwere all α-pyranose. 5.The optimal reactive condition of carboxylmethyl DFPA-Ⅰand vitriol esterified DFPA-Ⅰwere determined.The substituent degree of c更多还原