• Title/Summary/Keyword: Marine natural products

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Mild Isomerative Opening of Tetrahydrofuranyl Subunits in Steroids Using TFAT (trifluoroacetyl trifluoromethanesulfonate): Application to Synthesis of C17-OH Rockogenin Acetate

  • Lee, Jong-Seok;Kim, Byung-Sook;Shin, Jun-Ho;Lee, Yeon-Ju;Shin, Hee-Jae;Lee, Hyi-Seung
    • Bulletin of the Korean Chemical Society
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    • v.33 no.1
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    • pp.76-82
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    • 2012
  • A novel and efficient tetrahydrofuranyl ring opening method was developed using the highly reactive TFAT reagent in the presence of an acid scavenger, 2,6-di-tert-butyl-4-methylpyridine. Various acid sensitive groups are compatible with the reaction condition, making it generally applicable to many tetrahydrofuranyl steroids. Moreover, it is a synthetic equivalent of 'Marker degradation' affording an efficient synthesis of C17-OH rockogenin acetate.

Structure determination of Suberitenone B by Two-dimensional NMR techniques

  • Park, Jung-Rae;Youngwan Seo;Cho, Ki-Woong;Jongheon Shin
    • Journal of the Korean Magnetic Resonance Society
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    • v.1 no.1
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    • pp.71-77
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    • 1997
  • Substritenone B, sesterterpenoids of an unprecedented akeletal class, has been isolated from the Antarctic sponge Suberites sp. Structure of this compound has been determined by combined spectral and chemical studies.

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A New Analog of Antimycin from Streptomyces sp. M03033

  • Seo, Young-Wan;Cho, Ki-Woong;Rho, Jung-Rae;Mo, Sang-Jun;Shin, Jong-Heon
    • Journal of Microbiology and Biotechnology
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    • v.11 no.4
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    • pp.663-667
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    • 2001
  • A new secondary metabolite was isolated from the culture broth and mycelium of Streptomyces sp. collected from marine sediment. The structure of this compound was determined to be N-formylantimycic acid methyl ester, an acyclic derivative of antimycin, on the basis of combined chemical and spectral methods. The structure-activity relationship of antimycins is discussed.

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Bioactive Marine Natural Products

  • Son, Byeng-Wha
    • Korean Journal of Pharmacognosy
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    • v.21 no.1
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    • pp.1-48
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    • 1990
  • Marine organisms have proven to be rich sources of interesting organic molecules. A great number of compounds with diverse structural features and interesting biological activities have been isolated. Recent studies on secondary metabolites of marine organisms are discussed with a focus on a variety of biological activities and marine natural product literatures are also reviewed.

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New Polyene Macrolide Antibiotics from Streptomyces sp. M90025

  • Seo, Young-Wan;Cho, Ki-Woong;Lee, Hyi-Seung;Yoon, Tae-Mi;Shin, Jong-Heon
    • Journal of Microbiology and Biotechnology
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    • v.10 no.2
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    • pp.176-180
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    • 2000
  • Three polyene macrolide antibiotics including two new compounds were isolated from the culture mycelia of a Streptomyces species. The structures of these metabollites were determined as elizabethin, a previously reported 28-membered macrolide and two analohs, using combined spectroscopic methods. These compounds exhibited antifungal activity and cytotoxicity against a juman leukemia cell.

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Bioactive Metabolites from Selected Sponges of Korean and Tropical Waters

  • Shin, Jong-Heon;Park, Jung-Rae;Seo, Young-Wan;Lee, Hyi-Seung;Cho, Ki-Woong
    • Proceedings of the PSK Conference
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    • 2001.04a
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    • pp.90-94
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    • 2001
  • Wondonins A and B, aromatic alkaloids of an unprecedented skeletal class have been isolated form and association of the sponges Poecillastra wondoensis and Jaspis sp. In addition, four novel bromotyrosine-derived metabolites, psammaplins $A_1$ and $A_2$, aplysinellins A and B, have been isolated from the tropical sponge Aplysinella rhax. The structures of these compounds have been determined on the basis of combined chemical and spectral analyses. The new compounds exhibited significant cytotoxicity and antiangiogenic activity as well as inhibitory activities against farnesyl protein transferase and leucine aminopeptidase. In addition to these compounds, several bioactive metabolites have been isolated from sponges of Korean and tropical waters.

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