Studies On The Extraction Process, Structural Identification And Antiviral Activities Of Polysaccharides From E.gelatinae And E.striatum.

In this thesis, we studied the extraction, separation and structural identification of the sulfated polysaccharides(SP) from the algae Eucheuma gelatinae and Eucheuma striatum which were collected from the Cultivate base in Qionghai city of Hainan province. We also studied the antiviral activities against HSV-1 and CVB3 of the above SP samples. In addition, we studied the antiviral mechanism and relationship between the structure and the antiviral activities of the SP from E. gelatinae and E. striatum.The sulfated polysaccharides(SP) were extracted with hot water and fracted by KC1. They were separated by using DEAE-cellulose column chromatography. Their structures were determined by IR and GC-MS. The contents of the total polysaccharide, 3,6-anhydrogalactose and sulfate were analyzed by the methods of anthranone-sulfuric acid, resorcin and BaCl2 turbidimetry.The antiviral activities of the SP samples from E. gelatinae and E. striatum were studied by cell culture in vitro. Vero cells were infected by HSV-1, CVB3 and cultured with serial dilutions of the samples. The cell cytotoxicity(Vero) of the samples were evaluated by MTT method, The inhibitory effects were evaluated by cytopathic effect(CPE) method. The results showed that the SP samples from E. gelatinae and E. striatum had potent HSV-1-inhibitory, CVB3-inhibitory efficacy and lowcytotoxicity(Vero). The antiviral activities of some samples were better than the positive control drugs - acyclovir and ribavirin. The SP samples were not only able to kill the HSV-1 and CVB3, but also able to protect the Vero cells against the infection by the virus. The results also showed that the antiviral activities of the SP samples were related to the sulfate content, the molecular weight, the types of polysaccharides and the flexibility of the molecular chain.At last, we studied the extraction process of the polysaccharide (ESSPA) which had the most obvious antiviral activities from E. striatum. The best extraction process conditions were determined by the means of orthogonality.