Studies On Extraction And Purification Of Saponins From Radix Astragali

Huang Qi is the dry root of Astragalus membranaceus(Fisch.)Bge.var. mongholicus(Bge.)Hsiao or A.membranaceus(Fisch.)Bge,which includes saponins,flavonoids,polysaccharides and amino acids.Tu-Peng-fei has extracted 32 compounds from medical material.Total saponins have the effects of immunomodulation、cleaning free radical,in which astragalosideⅣis used for againsting stress、oxidation、inflammation and diuresis.A reasonable assaying method was set up on the basis of original study by studying on resin abstraction about saponins.Further,we depurated saponins in order to get saponins and flavonoids compounds.And we can gain purer saponins than before.By the means of amic solution hydrolysis,we converted other saponins into astragalosideⅣwhich is bioactive.The method simplify the procedure of determing content and improve the content of astragalosideⅣ.Enzymolysis is an advanced technology which is used for extracting active compound from plants.Enzyme can breakdown cells of plants moderately in order to dissolve component faster.We choose suitable enzyme to treat medical material before extracting using alcohol in order to improve yield,shorten time and save energy source.While,we can provid reasonable evidence to others about utilizing plants and manufacturing thoroughly.By using AB-8 macro-reticular resin,EtOH extracts of Radix Astragali is pured and we separate saponins from polysaccharides,using 4BV 80%alcohol is best for eluting.Further,alcohol eluant is adsorbed by ADS-22 polarity resin,and is eluted by distilled water、30%alcohol gradiently.We can separate saponins from flavonoids. By considerating vanillin concentration、heating time、temperature and ice bath time, we set up a suitable chromatometry to determine the content of saponins.By considerating single factor about amic solution hydrolysis,we set up the optimal technique of hydrolysis:the radio of amic solution to herb medicine is 1:5, concentration of amic solution is 2%,and the time of regurgitant extraction at 90℃is two hours.The verification test and technology consideration are valid.The content of astragalosideⅣis notably 16 times than before by hydrolysis.Difference isn’t significant between the concent of saponins before and after hydrolysis by colorimetry.Orthogonal design is adopted to investigate the main factors that influenced enzymolysis and the optimal technique of enzymolysis:concentration of cellulase is 0.7%,and the time of enzymolysis at 45℃,pH 4.5 is two hours.The content of saponins is higher 48%than that by alcohol extraction.Concentration of xylanase is 1.0%and the other factors are all the same,the content of saponins is higher 41%than that by alcohol extraction.