Study On Synthesis Methods Of S-Astragatan

With the rapid development of bio-molecular science, especially of the cytobiology, the function of sugar in many biology is continently found and recognized. The study of sugar drew interests,especially in chemically modifications of polysaccharide.In this paper,Works including the extraction of astragalanâ…¡derived from astragalus root have been reported.Astragatanâ…¡was a kind of D-dextrans. A kind of sulfated polysccharides was obtained and its struction was proved.1.The best conditions and methods of extracting astragatanâ…¡are indentified through comparing the effects of different methods such as water extraction-ethanol deposition and water extration-super filtration.The molecular weight is about 9000 of astragatanâ…¡by HPLC.2.Astragalus sulfated polysccharides(S- Astragatanâ…¡) was obtained from Astragatanâ…¡with chlorosulfonic acid-pyridine in this paper first.the best conditions of synthesis through comparing the effects of different conditions such as vol.proportion of chlorosulfonic acid-pyridine,reactive temperature and reactive time.Replace degree of S is 2.07.3. Structure of astragalus sulfated polysccharides was proved by HPLC,UV and IR.The HPLC chromatogram picture showed a single peak;the UV spectrum of S- Astragatanâ…¡showed the characteristic absorptions of sulfate ester bond at 250²75nm; the IR spectrum of S- Astragatanâ…¡showed the characteristic absorptions of sulfate ester bond at 1258cm^-1 and 815cm^-1 .these shows that synthesis of the sulfate ester is made.4. The 13C NMR spectrum of S- Astragatanâ…¡showed hydroxyl of C-6 is more active than those of C-2,C-3 and C-4.5. The characteristic of S-Astragatanâ…¡synthesized in this paper includes homogeneous component,lesser molecular weight and more replace degree of S.it may be a more biology-action sample for anti-AIDS and anti-tumour.