Structure And Bioactivities Of Degraded Lambda-carrageenan

The chemical modification of marine polysaccharides, which lead to preparation of derivatives with high biological activities and/or low toxicity, has attracted more and more attention. Chondrus ocellatus was an important economic alga that can produce carrageenan. In this article, lambda-carrageenan was obtained from Chondrus ocellatus and was degraded by microwave. After degradation we got the product PC2. We got three polysaccharides by separation and purification. The structures of polysaccharides and their activities such as antioxidation activity, immunity function were studied. The main research contents and results as follows:1 Three kinds of polysaccharides were prepared by anion-exchange column chromatography from degraded lambda-carrageenan PC2 which was obtained by microwave technique. The yield of them were 10.2%, 19.5% and 60.3% separately.2 The structures of these three polysaccharides were confirmed by GC, HPLC, UV, IR and NMR. The results indicated that the three polysaccharides are all made up mainly of galactose, small amounts of xylose and glycose. Every polysaccharide sample had uniformity molecular weight distribution. Three polysaccharides all contain sulfate group, but concentration of sulfate has significant difference. Their structure also had no significant difference, all hadβconfiguration glycosidic link. The configuration of glycosidic link may be changed by microwave degradation.3 The inhibitory effects of CF1, CF2 and CF3 on hydroxyl free radicals(OH·), superoxide(O₂^-·) and organic free radical (DPPH·) were measured. MDA formation in homogenates of liver induced by OH·generation system and H2O2 caused hemolysis of erythrocytes were inhibited distinctly by CF1, CF2 and CF3. Degraded lambda-carrageenan exerts its effect on antioxidation by scavenging OH·, O₂^-·and H2O2 in the biological system. Also, they showed DPPH·scavenging activity. The results showed that CF3 had the best antioxidation activity.4 T-lymphocytes and macrophage were obtained from healthy mice for improved lymphopoiesis test as well as macrophage cell for proliferation test and neutral red phagocytosis test. The results showed that degraded lambda-carrageenan could significantly promote spleen T lymphocyte proliferation with ConA and also increase phagocytic activity and NO production of murine peritioneal macrophages. Degraded lambda-carrageenan are able to advance the immunity of healthy mice. CF1 and CF3 had the better effect on immunocompetence in vitro.