Extraction, Characterization And Antioxidant Evaluation Of Polysaccharide From Salvia Miltiorrhiza

As a famous traditional chinese medicine, DanShen(Salvia miltiorrhiza Bunge) is a perennial herb which comes from Salvia, the largest genus of the Lamiaceae family. The roots and rhizomes have been used as herbal medicine for the treatment of cadiovascular disease for several thousands of years in China. Currently, The exploitation of DanShen is mainly focused on micromolecules such as soluble phenolic acids and fat-soluble diterpene quinone, while the macromolecules such as polysaccharides are still in its infancy. In this work, the polysaccharides from Danshen were extracted by hot water, ultrasonic, alkali and enzyme respectively. The structure of polysaccharides from Danshen were analyzed by several methods such as physicochemical properties analysis, SEM, IR and amino acid analysis. The antioxidant activities were examined by several methods, such as the DPPH radical scavenging assay, superoxide radical scavenging assay, hydroxyl radical scavenging assay. The purpose is to provide the scientific basis for effective development. The main research results are as follows:1. Danshen was defatted with petroleum ether and ethanol, then defatted extraction were execution by hot water, ultrasonic, alkali and enzyme respectively. Then they were subjected to Sevag method to remove free protein and to dialyse in order to remove micromolecules. Finally, four polysaccharides from Danshen were obtained by vacuum drying.2. The results of physicochemical properties analysis in four kinds of polysccharides from DanShen showed that the index of polysccharides by hot water and ultrasonic were exactly the same, while significantly different among polysccharides by alkali and enzyme.3. The results of SEM showed that the surface features of different polysccharides had significantly difference. They can easily be identified. Their dissolution efficiency were as follows:polysaccharide by alkali>polysaccharide by ultrasonic> polysaccharide by enzyme> polysaccharide by hot water.4. The results of IR analysis showed that four kinds of polysccharides had the general characteristic absorption peak of polysaccharides. The major functional groups were no significant different. Futhermore, they were allβ-pyranose. Then the results showed that they all have binding proteins and sulfate groups.5. The results of amino acid analysis showed that the composition and contents of amino acid in four kinds of polysccharides have significantly difference. The polysccharide by alkali have 16 kinds of essential amino acid and non-essential amino acid (Val is not detected). The others have 17 kinds of essential amino acid and non-essential amino acid. The amino acid contents of the four kinds of polysccharides were 11.04%, 16.88%,3.23% and 4.85% respectively. The essential amino acid contents of the four kinds of polysccharides were 4.17%,6.72%,0.78% and 1.59% respectively. It was worth nothing that the quata of the polysccharide by ultrasonic in the amino acid contents and the essential contents were the highest,16.88% and 6.72% respectively. On the contrary, the index of the polysccharides by alkali was the lowest.6. The results of evaluation of antioxidant activity showed that four kinds of polysccharides have some antioxidant activity. In the 0.40 mg/mL concentration of sample, the maximum value of DPPH radical scavenging were 84.09%,83.73%,37.34% and 82.23% respectively. In the 0.40 mg/mL concentration of sample, the maximum value of superoxide radical scavenging were 86.72%,89.45%,76.80% and 81.91% respectively. In the 0.40 mg/mL concentration of sample, the maximum value of hydroxyl radical scavenging were 42.89%,93.58%,25.20% and 47.90% respectively.