Studies On Secondary Metabolites Of Fungus Derived From Mangrove And Their Biological Activity

Due to the unique living conditions, marine fungus derived from mangrove environments possess special hereditary and physiological character, and have the capability to produce special secondary metabolites with unique skeletons and bioactivities which have important applications in the field of biomedicine, functional foods, Chemistry and Chemical Engineering and so on. Experimental results are as follows:1. Purification and optimization of fermentation conditions of marine fungus derived from mangroveThe associated two fungi, numbered PJX-29(not identified) and Cladosporium sphaerospermum (identified by our laboratory) were isolated and purified from marine mangrove forests soil by the PDA plate and the slant culture. At the same time, the two fungi’s fermentation medium has been optimized and selected the best fermentation medium condition is the second fungal liquid culture medium by the HPLC fingerprint and TLC.2. Secondary metabolites purification and structural analysis of the marine mangrove fungi PJX-29and Cladosporium sphaerospermumThe strains PJX-29and Cladosporium sphaerospermum have been fermented largely by the second fungal liquid culture medium, and the pure compounds have been got by the solvent extraction and variety of separation and purification methods (column chromatography, TLC, HPLC, semi-preparative HPLC and so on), then the pure compound’s structures were determined by modern methods of spectroscopy (UV, IR, NMR, X-Ray, CD and so on).Seven compounds, including monoglycerides,9",12"-heptadecadienoic acid,1-(hydroxymethyl)-2-[(1-oxohexadecyl)oxy] ethyl ester,6-pentyl-α-pyrone,4,6-dihydroxy-9,10-dimethylacetophenone, bis[8-8’-(7-hydroxy-4-methoxy-5-methylcoumarin)], hydroxybenzoic acid,6-aminobenzaldehyde were isolated from the fermentation products of strains PJX-29. Thirteen quinazolinone alkaloids, including glyantrypine, quinadoline B, tryptoquivaline, deoxytryptoquivaline, deoxynortryptoquivaline, seven new products and one new Natural Products were isolated from the fermentation products of strains Cladosporium sphaerospermum.3. Biological Activity Evaluation of the marine mangrove fungi PJX-29and Cladosporium sphaerospermumThe antioxidant activity against DPPH of these compounds from fungi PJX-29was assayed. Result shows two glyceride compounds have strong antioxidant activity, and their IC50are11.38±0.61and9.33±0.80. We concluded that the double bond, hydroxyl group in the structure exert antioxidant activity, they may the main active groups which can play antioxidant activity.The anti-tumor activities against several cancer cell lines of compounds from fungi Cladosporium sphaerospermum were assayed. Results show that compound14has weak anti-tumor activity against hela and A-549cells, and its inhibition of cell proliferation rates were65.72%and41.27%, compound13,15and16have weak anti-tumor activity against hela cells, and their inhibition of cell proliferation rates were35.46%,48.37%and36.07%.