| Radix Astragalus, used usually as a traditional Chinese medicine. It has many effects of replenishing'qi', depressing blood pressure, stimulating hearts, diminishing inflammation, promoting the subsidence of swelling, reinforcing immunity, and so on. Radix Astragalus is radix of astragalus membranacens Bunge and A. menbranacens var. mongolicus (bunge) Hsiao. The main efficiency component fuom Astragalus are Astragalus saponins and Astragalus polysaccharides.The objective of this issue is to optimize the technology of extracting valid components from astragalus. We want to design a method to extract saponin and polysac -charides, and determine its quantity with colorimetry. Then compare the quantity with those of traditional methods. The result is that the quantity of saponin extracted by non-water alcohol is more pure, after impurities being eliminated. The quantity of polysaccharides extracted in this method is more than that in traditional methods. The frozen-dried polysac-charide has good character,color, water-solubility. So we conclude that adopting the method designed in this technology to extract saponin and polysaccharides in radix astragalus can get better purity and quantity than those in traditional methods and it is optimal for the utilization of radix astragalus.the ethanol-alkali solvent was used to extract the saponin in radix astragalus.The optimum extraction condition is identified by the uniform design experiments.The extraction rate of saponin extracted by the ethanol-alkali solvent which reached 2.6496% was 1.08 times as much as that extracted by 95% ethanol which is reported to be a highest way and 1.54 times as much as that by 70% ethanol in soxhlet which is an often used way. The crude saponin was prepared by 1-butanol and chromatographed on the macroporus resin column and silicagel column. At last, three types of elements which were labeled S31,S32 and S33 were obtained and were identified to be purities by TLC.The scavenging rate of S31, S32 and S33 for superoxide radically and hydroxyl radical were so determined, compared with that of S11,S12 and S13 which were extracted by soxhlet way.It is found that the scavenging rate of S11,S12 and S13 for hydroxyl radical were 54.86%,19.63% and 24.82%,as well as that of S31,S32 and S33 were 60.2%,20.8%and23.1%.The hydroxyl radical scavenging ability of S31 and S32 were 5.52% and 1.8% higher than that of S11 and S12. The hydroxyl radical scavenging ability of S33 is 1.17% less than that of S13. The scavenging rate of S11,S12 and S13 for superoxide radical were 12.48%,6.71%and 26.56% as well as that of S31,S32 and S33 were 12.68%,8.84%and 15.46%.The scavenging rate of S31 was as same as S11,S32 was 2.1% higher than S12,S33 was 11.11% less than S13.It is indicated that the saponin extracted by ethanol-alkali solvent has the scavenging ability of hydroxyl radical and superoxide radical.This paper studied on extraction methods of valid componpents astragalus as index to study the effects of five extraction factors by single factor investigation , the ratio of material to extraction solvent, extraction time, extraction temperature and ethanol concentration of extraction solvents. The extraction rate of astragalus polysaccharides extracted by the water extraction method and alkali extraction method was detected by ultraviolet spectrophotometry and infrared spectrometry. The results showed that the best extraction solvent is 1:10, the best extraction temperature is 90℃, the best extraction time is 1.5 hours. In this method the extraction rate of ethanol-alkali extraction method is better than the other methods.In conclusion, it is resulted that this method can get hihger extraction rate than traditional ways for extracting the valid components in the Chinese tradition medicine such as asponin and polysaccharide. Especially, it can improve the extraction rate for polysaccaride clearly. It will be useful in very variety of applications for extraction of the efficiency components.
|
PDF Full Text Request