The Polysaccharide And Chemical Constituents In Green Alga Codium Species And Their Preliminary Biological Activities Research

This thesis was divided into 2 parts. In Part 1, the isolation, partial purification and physicochemical characterization of sulphated polysaccharides from Codium cylindricum of South China Sea were studied. In vitro antiviral activities of the polysaccharides against HSV-1 and CVB₃ were carried out and preliminary antiviral mechanism was studied.Sulphated polysaccharides were extracted with the method of hot water and Sodium Cloride fractionation. The polysaccharide which contents most sulphate functional group was applied to DEAE cellulose column chromatography for further fractionation. Total sugar, 3,6-anhyrogalactose and sulphated contents were determined by the method of anthranone-sulfuric acid, resorcin and BaCl₂ turbidimetry, respectively. The functional groups were further confirmed by infrared spetrum. Hydrolyzation and derivatization of polysaccharides were done and the monosaccharide compositions were determined by the method of GC-MS.In vitro cell cultures were applied to study the antiviral activities of polysaccharides. MTT method was used to determine the cytotoxicity of polysaccharides and the cytopathic effect reduction (CPE) method was used to observe the inhibitory effects. The results indicated that these polysaccharides showed good inhibitory effects against both viruses in extracellular inhibitory instead of intracellular inhibitory.In Part 2, the isolation and structural elucidation of chemical constituents in Codium fragile and the antibacterial assays of the crude extracts were studied. Thin layer chromatography, vacuum column chromatography, column chromatography and gel chromatography were applied to the separation and purification process of the crude extracts. The structures were determined by infrared spectra (IR), nuclear magnetic resonance (NMR), mass spectrometry (MS), elemental analysis, etc.Six chemical compounds and a mixture of fatty acids were isolated and the structures were determined to be as: (1)decortinone; (2)1-O-palmitoyl-2-O-β-D-galacto-pyranosyl-3-O-(9-octadecenoyl)glycerol; (3)clerosterol3-O-P-D-glucopyranoside;(Dazelaic acid; (§)a mixture of 4 fatty acids: dodecanoic acid, tetradecanoic acid, hexadecanoic acid and octadecanoic acid, confirmed by the method of GC-MS. Partial structural elucidation of other 2 compounds were done. Compound (2) was confirmed as a new compound, and (3) and ? were first time isolated from green alga Codium species.Antibacterial assay of the crude extracts of Codium fragile on 8 bacteria strains had been studied. Minimal inhibitory concentration (MIC) was used to determine the antibacterial efiFects of the samples. The results indicated that ethanol extract and petrol ehter extract showed inhibition against a few bacteria strains in high concentration.The fatty acids compositions and elemental composition in both Codium cylindricum and Codium fragile were studied too. The results indicated that both unsaturated fatty acids and elemental contents in C. fragile were abundant compared to C. cylindricum.