Study On Bioactivity Of Fungi From Mangrove And Research Of Fermentation And Properties Of Deacetylmycoepoxydiene

Because of their special living conditions, marine microorganisms often produce various bioactive substances with novel functions and structures. Therefore marine microorganisms, as the new sources of bioactive substance, have received people's great attention in recent years.Mangroves are special host plants and habitats of fungi. Mangrove fungi can produce many kinds of metabolites with great potential for anti-microbial and anti-tumor medicinal ues.In this study, 202 fungi were isolated from fresh leaves, dry twigs and dead leaves of Bruguiera gymnorrhiza and Bruguiera sexangula, which were collected from Fugong, Fujian in 2007. Crude fermentation extractions of these fungi were screened by three different bioactive assays: anti-microbial activity assay, anti-oxidation activity assay and anti-tumor activity assay. The results showed that extractions from 47 strains displayed at less one kind of bioactivities: 19 strains (9.4%) displayed anti-microbial activities on one or more than one of 5 indicator organisms. The strains with anti-oxidation activity were 22 (10.9%). 23 strains (11.4%) displayed anti-tumor activity on Hela cell line, 6 of them also against SW480 cell line.The identification of 68 fungi by ITS rDNA assay indicated that the strains were distributed in at least 10 generas. And the bioactive fungi were mainly distributed the Phomopsis sp. (35.3%), Diaporthe sp. (14.7%) and Penicillium sp. (8.8%).Deacetylmycoepoxydiene, a second metabolic product by Phomopsis sp.818, containing an oxygen-bridged cyclooctadiene, is novel and represents a new class of fungal metabolites. The IC₅₀ of Raji cell line is 3.0ug/mL But the low yield hinders the deeply research.By using Response Surface Method, the yields have increased considerably. Based on the results of One-factor experimental design and Plackett-Burman design, the most important factors were further investigated with Box-Behnken and Response Surface Analysis. The results showed that mannitol 12 g/L, glucose 25.56 g/L, potatoes 231.82 g/L, the production of deacetylmycoepoxydiene reached to 108.9mg/L, which was double than before.Deacetylmycoepoxydiene has been proved to be a new and promising anti-tumor drug. By means of influential factor experiment, accelerating experiment and long term experiment, using the techniques of HPLC, IR, UV and so on, we study on the character, identification, purity investigation, content determination, light stability and heat stability of Deacetylmycoepoxydiene.Based on the results, quality standard was set up. The stability experiment was according to the quality standard. Deacetylmycoepoxydiene is stable under high temperature(60℃), high moisture(RH 90%) and violet light(5000 Lx). It can be stored at airtight and common temperature conditions. This study laid the foundation for follow-up development.