| Sargassum henslowianum C.Agardh, a kind of economic seaweed growing in the South China Sea, is rich in chemical components and possesses wide bioactivities. However, only polysaccharose from S. henslowianum and its bioactivities have been investigated in recent year. In this research, the secondary metabolites components and their bioactivities of S. henslowianum will be investigated and analysed for drug lead compounds screening.Ethanol crude extracts and different polar fractions of S. Henslowianum gained by solven extraction and liquid-liquid extraction were separated and purified by various methods including silica column chromatography, Sephadex LH-20 chromatography, thin layer chromatography, high phase liquid chromatography. GC-MS, LC-MS and NMR were used for component analysis and structure characterization. Antioxidant activities of different extracts of S. Henslowianum were investigated by methods such as 2,2-diphenyl-1-picrylhydrazyl scavenging, agreement of basic telecommunications services scavenging and oxygen radical absorbance capacity. The antibacterial activity was detected by filter paper method and anti-hypolipidemic activity was evaluated via in vivo. The results are as follows:(1) 4 compounds(4-hydroxy-2(E)-nonenoic acid, dioctyl phthalate, dibutyl phthalate, acetic acid 3-hydroxy-3,4,4,6-tetramethyl-7,8-dioxo-cyclonon-5-enyl ester were isolated and characterized from S. Henslowianum. The results of gas chromatography-mass spectrometer showed that partial components in extracts from S. henslowianum were fatty acids and esters with tiny amount of ketones and lactones. The results of liquid chromatography-mass spectrometer showed that nitrogen-containing compounds, sulfocompounds and phenylhalosrannyl were rich in extracts from S. henslowianum.(2) The results of antibacteria assay showed that ethanol crude extracts and different polar fractions of S. Henslowianum exhibited inhibition activity against 6 different kinds of bacterium with inhibitory circle ranges 6.5 from 8.5mm. Petroleum ether fraction had no effect against gram positive bacteria. n-butanol fraction exhibited strongest antibacteria activities against escherichia coli with inhibitory circle of 9.1mm, and aqueous fraction only inhibited the growth of pseudomonas aeruginosa with inhibitory circle of 9.2mm.(3) The results from antioxidant assay in vitro showed that ethanol crude extracts anddifferent polar fractions of S. Henslowianum exhibited antioxidant effects. There were a positive correlation between antioxidant effects and concentrations in range of 0.125~2mg/m L. Ethyl acetate fraction among all fractions exhibited strongest activities, which the values of IC50 based on DPPH and ABTS were 0.89±0.01 mg/m L and 0.73±0.03 mg/m L respectively, and the values of ORAC was 1803.78±81.37 μmol Trolox equivalents /g.Aqueous fraction showed the poorest effect which the values of IC50 based on DPPH and ABTS were 2.11±0.11 mg/m L and 1.77±0.02 mg/m L respectively, and the values of ORAC was 1172.83±83.86 μmol Trolox equivalents /g.(4) The results of animal experiment showed that two doses of extracts from S.henslowianum decreased significantly the levels of total cholesterol〠triglyceride 〠low density lipoprotein-cholesteroã€arteriosclerosis1ã€arteriosclerosis2 of hyperlipidemia mice,and increased the contents of high density lipoprotein-cholesterol and lipoprotein lipase activities in serum(p<0.05). Also, ethanol crude extracts of S. Henslowianum improved effectively the mice antioxidant capacity in vivo, which increased significantly total antioxidant capacity assay kit and catalase activities, and decreased significantly the content of malondialdehyde in liver.In conclusion, the results of this study enrich the theory on the chemistry and activity of S. Henslowianum and provide the basis for exploiting and utilizing S. henslowianum. |
