Taichunamides: Prenylated Indole Alkaloids from Aspergillus taichungensis (IBT 19404) |
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| Authors: | Ippei Kagiyama Dr. Hikaru Kato Dr. Tatsuo Nehira Prof. Jens C. Frisvad Prof. David H. Sherman Prof. Robert M. Williams Prof. Sachiko Tsukamoto |
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| Affiliation: | 1. Graduated School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan;2. Graduated School of Integrated Arts and Sciences, Hiroshima University, Higashi-hiroshima, Japan;3. Section for Eukaryotic Biotechnology, Departments of System Biology, Technical University of Denmark, Kongens Lyngby, Denmark;4. Life Sciences Institute and Departments of Medicinal Chemistry, Chemistry, Microbiology & Immunology, The University of Michigan, Ann Arbor, MI, USA;5. Department of Chemistry, Colorado State University, Fort Collins, CO, USA |
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| Abstract: | Seven new prenylated indole alkaloids, taichunamides A–G, were isolated from the fungus Aspergillus taichungensis (IBT 19404). Taichunamides A and B contained an azetidine and 4‐pyridone units, respectively, and are likely biosynthesized from notoamide S via (+)‐6‐epi‐stephacidin A. Taichunamides C and D contain endoperoxide and methylsulfonyl units, respectively. This fungus produced indole alkaloids containing an anti‐bicyclo[2.2.2]diazaoctane core, whereas A. protuberus and A. amoenus produced congeners with a syn‐bicyclo[2.2.2]diazaoctane core. Plausible biosynthetic pathways to access these cores within the three species likely arise from an intramolecular hetero Diels–Alder reaction. |
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| Keywords: | alkaloids biosynthesis cycloaddition natural products structure elucidation |
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