Polysaccharide Sulfate Polysaccharide Structure And Antioxidant Activity Of A Preliminary Study

Codonopsis Pilosula polysaccharide is one of the main functional components in Codonopsis Pilosula.It has many functions,such as anti-age,anti-fatigue,anti-tumor and anti-radiation.Codonopsis Pilosula polysaccharide is broad attended because of its various pharmacological effect and biological function.Most crude polysaceharides were used in Pharmaeologieal experiment,the study were seldom carried out on isolation,purifieation,sulfated,structure-function relationship of polysaccharide from Codonopsis Pilosula.In this thesis,several polysaceharides were extracted and purified from Codonopsis Pilosula,and their sulfated polysaceharides were prepared.The chemical structure of the polysaceharides and their sulfated polysaceharides were studied,and their Antioxidant Activities were investigated.The main results showed:1.Primary study on separation,purification and structure of Codonopsis Pilosula polysaccharide: The total polysaccharide (APO) was extracted with hot water from Codonopsis Pilosula. Treated APO with Cetyltrimethyl Ammonium Bromide (CTAB),three fractions were isolated,named AP1 and PP2, respectively .The content of polysaccharide is determined by phenol-sulphuric acid method, and the results showed that the polysaccharide contents were 67.6%and 47.4%, respectively.The content of uronic acids in polysaceharides is determined by sulfuric acid carbazole colorimety method, and the results showed that the contents of uronic acids were 5.6%and 2.4%, respectively. A HPLC method was developed to determine the average molecular weight of polysaccharides.The the results showed that the average molecular weights were 9.47×10³ Dal and 9.72×10³Dal, respectively.UV scanning spectrum manifested that two kinds of polysaceharides haven't protein and nucleic acid.The primary structure of AP1 and PP2 was studies by periodate oxidation,Smith degradationand IR.The results suggested that two kinds of polysaceharides have common spectral characters of polysaceharides. AP1 wasα-pyranose and its main chain was made up of (1â†'3,4) glucose and galactose.PP2 was puranoses and its main chain was made up of (1â†'3,4) glucose, fructose and arabinose.Studies on the two kinds of polysaceharides by atomic force microscopy(AFM) indicated that molecule of Codonopsis Pilosula polysaceharides were muti-branched structure,single molecular chain as well as side branches,polymer chain moleculars were twisted with each other and a variety of different linkages between adjacent monosaccharides, which compose different rings structure.2.Preparation of sulfated polysaceharides and primary study on structure of Codonopsis Pilosula polysaccharide: AP1,PP2 which were sulfated by chlorsulfonic acid-pyridine were convert ed into AP1-S,PP2-S.The content of sulfate radical and degree of substitution in the polysaccharide were determined by the method of BaSO₄^2- turbidimetry.The sulfate radical contents were 13.5% and 10.15%,respectively and degree of substitution were 1.2 and 0.76, respectively.A HPLC method was developed to determine the average molecular weight of polysaccharides.The results showed that the average molecular weights were 9.67×10³Dal and 1.02×10⁴Dal, respectively. The average molecular weight of AP1-S,PP2-S are on the increase.UV scanning spectrum and IR spectrum indicated that both of two polysaccharides have typical char- acteristic spectrum of Codonopsis Pilosula polysaccharides and apparent sulfated group of sulfated polysaccharide.The primary structure of AP1-S and PP2-S was studies by periodate oxidation, Smith degradationand IR.The results suggested that two kinds of polysaccharides have common spectral characters of polysaccharides .AP1-S wasα-pyranose and its main chain was made up of (1â†'3,4) glucose and galactose. PP2 -S was puranoses and its main chain was made up of (1â†'3,4) glucose, fructose and arabinose. AFM analysis indicated that there are obvious similitude in surface morphology among AP1,AP1-S , and PP2 .But PP2 was take on sheet congeries .3.Study on the Antioxidant Activity of Codonopsis pilosula polysaccharide and sulfated codonopsis pilosula polysaccharide: The vitro scavenging action of AP1, AP1-S,PP2, PP2-S on superoxide radical and hydroxyl radical was investigated in this study.The result showed that four kinds of polysaccharides (AP1,PP2,AP1-S,PP2-S) ,in which AP1 is the best, have the effect which increases with the increasing of concentration on scavenging hydroxyl radicals. Similarly, PP2,AP1-S,PP2-S have also the effect which increases with the increasing of concentration on scavenging superoxide radical. However, AP1 haven't the effect on scavenging superoxide radical.The results of this foundation research mentioned above not only have reference value, but also provide data for the exploration of new drugs from Codonopsis Pilosula. as a result of understanding of The chemical structure of the polysaccharides and their Sulfated polysaccharides,as well as the correlation of structure to the Antioxidant Activities.