Study On Isolation ,Purification, Structure And Biological Activity Of Active Polysaccharides From Dioscorea. Fordii Prain Et Burkill

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...