| Summary: | 碩士 === 國立中山大學 === 海洋生物科技暨資源學系研究所 === 101 === Part one:Studies on the Chemical Constituents of the Marine Microbe, Vibrio proteolyticus and their Biological Activities
Acinetobacter baumannii, an opportunistic human pathogen which shows resistant to many clinic antibiotics, is one of the major causes of nosocomial infections. The aim of the project is to search novel antibiotics to treat A. baumannii and its mutant strains. We isolated a marine bacterium (Strain QWI06) from the sediment of Da-Peng-Wan National Scenic Area, of which the organic extract exhibited significant inhibitory effect against six bacterial indicators (Staphylococcus aureus, Bacillus cereus, Klebsiella pneumoniae, Escherichia coli, Acinetobacter baumannii, and Candida albicans). We further identified it as Vibrio proteolyticus according to the 16S rRNA analysis. By bioactivity-guided fractionation isolation, we isolated ten new tyrosine-lipid derivatives of compounds, named vitroprocines A-J (11~20), together with eleven known compounds, including six diketopiperazines, two nucleosides, two indoles, and a benzyl derivative from the organic extract of this marine bacterium. the structures of these isolates were elucidated by spectroscopic methods (UV, IR, CD, NMR, and HR-ESIMS) and chemical modification (Mosher’s method). In addition, results of bioactive tests indicated that vitroprocine A (11) exhibited significantly anti-microbial activity against A. baumannii with a minimum inhibitory concentration of 8 μg/mL. The antiviral test revealed that cyclo-(4-trans-OH-L-Pro-L-Leu) (2) and cyclo-(L-Pro-L-Val) (5) showed inhibitory effect against Hepatitis C virus with SI (CC50 / EC50) value of 1.83 (2) and 1.36 (5), respectively. The SI value of cyclo-(L-Pro-D-Trp) (4) and vitroprocines A and D (11 and 14) against Dengue virus were 1.3 (4), 2.2 (11), and 1.6 (14), respectively.
Keywords：Vibrio, Vibrio proteolyticus, vitroprocines, Acinetobacter baumannii, Anti-microbial Activity
Part two:Studies on the Chemical Constituents of the Thermophilic Fungus, Asperillus fumigatus and their Biological Activities
Asperillus fumigatus, belonging to Genus Asperillus, is one of the most common fungi ubiquitous in the environment all over the world. Hundreds of bioactive secondary metabolites have been isolated from the fungi of Genus Asperillus. We cultured A. fumigatus with PDA agar, and extracted the fungus and medium with ethyl acetate. The extracts were subjected to flash silica column chromatography and high performance liquid chromatography to give seven compounds, including (+)-terrein (1), 3-methyl-6-hydroxy- 8-methoxy-isocoumarin (2), 6,7-dimethoxy-4-hydroxymellein (3), 4,6-dihydroxymellein (4), asterric acid (5), butyrolactone I (6), and butyrolactone II (7). All the chemical structures were characterized by spectroscopic methods (UV, IR, NMR, and HR-ESIMS). Furthermore, the antivirus test revealed that 3-methyl-6-hydroxy-8-methoxyisocoumarin (2) and 4,6-dihydroxymellein (4) exerted inhibitory effect against HCV’s with SI (CC50/ EC50) values of 5.5 (2) and 4.5 (4), respectively.
Keywords：Thermophilic fungi, Asperillus fumigatus, Anti-virus Activity
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