Study On Sulfation, Physicochemical Properties And Biological Activities Of Bletilla Striata (Thunb.) Reichb.f. Polysaccharide

Polysaccharides have many kinds of biological activities, such as antitumor, antivirus, antitumor, anti-oxidant, and they can enhance the function of immune system, and so on. More and more attention has been paid to study on polysaccharide. Especially many polysaccharide sulfates can resist HIV and many other kinds of virus, so it particularly attract people's attention.We mainly studied sulfation-techniques, physicochemical properties and biological activities of the Bletilla striata (Thunb.) Reichb.f. polysaccharide sulfates. Firstly, we synthesized Bletilla striata (Thunb.) Reichb.f. polysaccharide sulfates with chlorosulfonic acid-pyridine and chose three main factors: volume ratio of chlorsulfonic acid and pyridine, temperature and time of reaction. The orthogonal test design L9(34) was used for studying the optimization of the sulfation-techniques. The result showed that the condition of 6:1 volume ratio of pyridine and chlorine sulfonic acid, 85 C, 2-3h helped to improve yield of products and degree of substitution.The preparation was treated through DEAE-52, Sephadex G-75 and Sephadex G-100 column to separate and purify. Two components of different molecular weight SBR1 and SBR2 were found. Their molecular weight was determined by GPC and the structure was determined by UV-spectrum, IR spectrum and NMR. The result showed the polysaccharide's conformation and other physicochemical properties were changed by sulfate radical. With regard to their biological activities, we studied their activities of scavenging O2 and. OH and their influence on the H2O2-induced hemolysis of RBC. We also studied their effects on B lymphocyte in vitro, human cervical cancer CaSKi cells in vitro, leukaemia cell U937 in vitro. The results showed SBR1 and SBR2 had distinctive effect on clearingO2, but BR had no the same effect. BR could obviously scavenge . OH and low concentration of SBR1 and SBR2 had the same action, but high concentration of SBR1 and SBR2 generated a complex combination of polysaccharide-cytochrome C and brought sediment. SBR1 and SBR2 couldn't alleviate H2O2-induced hemolysis of RBC, but low concentration of BR had the effect of alleviating of H2O2 -induced hemolysis of RBC. This because of that macromolecule polysaccharides are apt to make RBC assemble. SBR2 could promote the proliferation of B lymphocyte and with the concentration rising its effect rised firstly then dropped. They all had no effect on human cervical cancer CaSKi cells, but SBR1 and SBR2 had comparatively obvious inhibition to leukaemia cell U937.BR had no obvious inhibition to leukaemia cell U937.