Isolation, Purification And Bioactivity Study Of Sulfated Polysaccharide-Protein Complex From Laminaria Japonica

Objective: From laminaria japonica, a sulfated polysaccharide-protein complex (SPPC) was isolated and purified, which was further separated on anion-exchange column. Bioactivities of SPPC and its fractions were studied and evaluated.Materials and methods: 1. Crude SPPC (CSPPC) was isolated from laminaria japonica; further isolation and purification were made from CSPPC to get SPPC by ethanol fractionation. Based on the bioactivities of SPPC, further separation was done to get four different fractions of SPPC-0.5M, SPPC-IM, SPPC-1.5 M and SPPC-2 M on anion-exchange column.2. Composition and molar ratio of monosaccharide in CSPPC were analyzed by GC, as well as molecular weight by GPC. SPPC was analyzed focusing on the main compound, such as content of sulfate, total polysaccharide and protein with the help of spectrophotometric method. Composition of monosaccharide and molecular weight of SPPC and its fractions were analyzed with the help of above methods. 3. After the composition determination of the SPPC and its fractions, further bioactivities were made, which included: In vitro, free radical scavenging activities of SPPC and its fractions by ESR, and their anti-virus activities as well. In vivo, antioxidant effects and immunoloregulation functions of SPPC on S-180 tumor-bearing mice.Results: 1. Main composition of monosaccharide in CSPPC was L-fucose,α-rhamnose, D-arabinose, D-xylose, D-mannose, D-galactose and glucose, which molar ratio was 1.0∶0.04∶0.13∶0.09∶0.48∶0.26∶0.09(L-fucose's molar was consider as 1.0). GPC graph of CSPPC indicated that there was some kind of interaction between polysaccharide and protein, and its molecular weight was over one million Dalton. The contents of sulfate, total polysaccharide and protein in SPPC were 26.47%, 37.63% and 2.84% respectively. And the molecular weight of SPPC was over 900 thousand Dalton, which composition of monosaccharide was mainly L-fucose and galactose. 2. In vitro, the antioxidant effect such as free radical scavenging rates of SPPC on superoxide anion, hydroxyl and lipid were 39.65% (8mg/ml), 47.91% (10mg/ml) and 23.65% (4mg/ml) respectively. In addition, related to its antioxidant effects of four fractions, the anti-virus effects were further identified. Moreover, SPPC showed that could modulate the activities of antioxidase and inhibit the production of MDA, and regulate immunity on tumor-bearing mice as well.Conclusion: Main monosaccharide of SPPC mainly is L-fucose and D-galactose, which is giant molecule. SPPC and its four fractions all have activities of anti-oxidation, anti-virus and immunoloregulation.