| The thesis is aimed to develop herbal resources of Southern Shannxi through researching the dried buds and flowers of Tussilago farfara. This thesis has a systematic study focused on the extraction,related dynamics,isolation,purification, structure characterization and external antioxidant activity of polysaccharide from Tussilago farfara. This paper, mainly achieves the following results:(1) Tussilago farfara polysaccharide was obtained by using hot water extraction and ultrasonic wave extraction.On the basis of one-factor tests,the method of response surface analysis(RSA) was carried out to determine the optimal condition of the extraction. The using hot water optimum extraction conditions were as follows:84℃,124min,21 (water/dry weight),3 times. The extract rate of polysaccharide is 1.862% based on the above mentioned conditions. The ultrasonic wave extraction optimal condition were:ultrasonic extraction power 90W,71℃,40min,25 (water/dry weight),3 times.Under the optimized condition,the extraction rate of polysaccharide was 2.204%. The result shows that the ultrasonic method is time-saving,lower temperature and higher the extraction rate of polysaccharide,compared with using hot water. However, the polysaccharide structure may be changed by using of ultrasonic wave extraction.(2) Respectively, the kinetic model in extracting the polysaccharide from Tussilago farfara were establishde by using hot water and ultrasonic wave. And the polyphenol and flavonoids rate constant of extraction, residual rate of extraction, activation energy, half-life, a series of effective diffusion coefficient of the kinetic parameters were obtained. The results provide the theoretical basis and reference for the design and optimization of extraction conditions used in the polysaccharide from Tussilago farfara.(3) Process of removing protein and decolorization were studied and optimized.Process of removing protein:By comparing the four methods of protein removal including by hydrochloric acid, trichloroacetic acid, Sevage method and papain-Sevage, papain Sevage method was choosed as the optimal method finally. The optimum conditions were substrate concentration 2% of papain, pH 7.0, temperature 65℃, hydrolysis time 93min, repeat 3 times with Sevags method. The amount of protein removed was 82.63% while polysaccharide remained 87.83% during the deproteinization process.Process of decolorization:Contrasting four decolorization methods such as hydrogen peroxide oxidation method, activated carbon attaching method, reverse micelle solution method and macroporous rosin adsorption method, it was macroporous rosin adsorption process that had the most effect in decolorizing polysaccharide from the dried buds and flowers of Tussilago farfara. Through static adsorption, desorption, dynamic adsorption, desorption experiments, relative parameters of adsorption kinetics and thermodynamics are acknowledged. The result is shown that XD-5 resin was used to determine the optimum adsorption conditions for this method. The sample was 2BV with the current velocity of 1.5BV/h meanwhile the sample mass concentration was 5.0 mg/mL. The decolorazation rate was 90.04%, and the protein removal was 91.42% in all after disposal while polysaccharide retention rate was 85.38%.(4) Three FPI that was deproteinized,decolored and dialyzed fractions,FPA,FPB and FPC,were got by DEAE-Cellulose column and sephadex G-200 using different solvent. The physicochemical properties of FPA and FPB were studied.The result was show that FPA was a kind of water soluble polysaccharide. The total sugar content is 93.1%,and the uronic acid is 10.7%.The average molecular weight of FPA is 456.6K Dal.The unit monosaccharide of FPA was identified as mannose,glucose, galactose with a ratio of 2.467∶1.158∶1,the sugar chain of FPA is manily composed of 1→2 linked,1→6 linked,1→linked and 1→3 linked.1H-NMR and IR spectrum of FPA results showed that monosaccharide of FPA wereαandβ-pyranose.FPB was a kind of water soluble polysaccharide. The total sugar content is 99.2%.The average molecular weight of FPB is 5.5KDal.The unit monosaccharide of FPB was identified as mannose,glucose with a ratio of 1.798∶1,the sugar chain of FPB is manily composed of 1→linked, 1→3 linked and 1→3,6 linked.1H-NMR and IR spectrum of FPB results showed that monosaccharide of FPA were manilyβ-pyranose.(5) Tussilago farfara polysaccharides had the cleaning capability of superoxide radical,hydroxy radical, nitroso and DPPH.Especially the nitroso and DPPH had satisfied scavenging effect. The cleaning capability of nitroso and DPPH had a dose-effect relationship obviously.The results of this study provide a new way for the resources of Tussilago farfara of comprehensive utilization and for similar studies certain reference, with better economic, social value and prospects.
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