Title page for etd-0720114-111443


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URN etd-0720114-111443
Author Er-mao Hung
Author's Email Address 9710131@gmail.com
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Department Marine Biotechnology and Resources
Year 2013
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Studies on the Chemical Constituents of the Marine bacterium, Microbulbifer variabilis and Marine Fungus, Nemania maritima and Their Biological Activities
Date of Defense 2014-07-30
Page Count 296
Keyword
  • Microbulbifer variabilis
  • anti-microbial activity
  • Hepatitis C virus
  • Nemania maritima
  • mass spectral molecular networking
  • Dengue virus
  • Abstract Marine organisms are regarded as an immense resource of diverse natural products for drug discovery and development, such as trabectedin from tunicate, marinisporolide A1 form Marinispora sp. and so on. In our lab, we got symbiotic marine bacteria C-01 from Cerviconia sp, C-03 and C-07 from Palythoa sp., and C-05 from Npphates sp., respectively, in Wan-Li Tong, Pingtung County. Based on 16S rRNA gene sequencing analysis, they all were identified as Microbulbifer variabilis We compared with four Microbulbifer strains by HPLC-PDA-MS fractionations and the mass spectral molecular networking to explore relationship of secondary metabolites. We further explored the bioactive components from the C-03 by chromatographic methods. Till now, one new diketopiperazine 8, as well as ten 1~7, and 9~11, six nucleotides 12~17, one pyridine 18 one pyrrolidine 19, one benzoic acid 20 and, one phenazine 21, have been isolated from the ethyl acetate extract of M. variabilis C-03. We also explored marine fungus with Nemania maritima, belonging to genus Nemania. This fungus was isolated from the mangrove dead wood. We cultured N. maritima with PDA agar, and extracted the fungus with ethyl acetate. The extracts were subjected to traditional silica column chromatography and high performance liquid chromatography to give four compounds, including adenosine (22) barceloneic acid A (23), barceloneic acid B (24) and ergosterol peroxide (25). All the chemical structures were characterized by spectroscopic methods (UV, IR, NMR, and ESI-MS).
    We test three kind of bioactive test about anti-bacterial, anti-virus (hepatitis C virus and dengue virus). Compound 21 showed significant anti-microbial activity against to Staphyloccocus aureus and Bacillus cereus with the same minimum inhibitory concentration (MIC) value of 8 μg/mL. In addition, the antiviral test revealed that against hepatitis C virus with SI (CC50/EC50) value of 21 was 4.06. The SI values of 5, 6, 10, 12 and 13 against dengue virus were 5.89、7.41、8.92、13.33, and 8.19, respectively. In addition, the compounds of 24 and 25 did not find the relevant reports in past literature about anti-virus activity. Anti-bacterial and anti-virus (hepatitis C virus) have not significant inhibitory effect, but we find compound of 24 and 25 exerted inhibitory effect against dengue virus’s with SI (CC50/EC50) values of 4.67 and 9.52, respectively.
    Advisory Committee
  • Jyh-horng Sheu - chair
  • Yu-Liang Yang - co-chair
  • Chih-Chuang Liaw - advisor
  • Files
  • etd-0720114-111443.pdf
  • Indicate in-campus at 5 year and off-campus access at 5 year.
    Date of Submission 2014-09-09

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