Study on the extraction, purification and antioxidant activity of polysaccharide in Centella asiatica
Abstract: In this study, the Centella asiatica was extracted with water and Centella asiatica crude polysaccharide protein was obtained with a productivity of 6.5%. The protein content of the Centella asiatica crude polysaccharide measured with Coomassie brilliant blue G-250 method was 3.45%. The crude polysaccharide was deproteined with enzyme and Sevag, after handling 8 times there was no obvious protein layer left. Took the Coomassie brilliant blue G-250 method again , and result showed that there was little protein contained in the crude polysaccharide, the effect of deproteinning was good. The polysaccharide content of the deproteined crude polysaccharide was measured with phenol and sulfuric acid, hexose had a content of 57.9%.
The antioxidant activity of crude polysaccharides was also studied by β-carotene bleaching assay, which showed that Centella asiatica crude polysaccharides have distinct antioxidant capacity compared with vitamin C as the positive control.
We us the GC method to test the monosaccharide composition of Centella asiatica polysaccharides, and the result showed that maltose and D-xylose are two compositions of crude polysaccharides.
Key Words：Centella asiatica; Polysaccharides; Extraction; Antioxidant activity
