Taichunamides: Prenylated Indole Alkaloids from Aspergillus taichungensis (IBT 19404)

• Published in: Angewandte Chemie Vol. 128; no. 3; pp. 1140 - 1144
• Main Authors: Kagiyama, Ippei, Kato, Hikaru, Nehira, Tatsuo, Frisvad, Jens C., Sherman, David H., Williams, Robert M., Tsukamoto, Sachiko
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 18-01-2016; Wiley Subscription Services, Inc
• Subjects: Alkaloide; Alkaloids; Aspergillus; Biosynthese; Chemistry; Congeners; Cores; Cycloadditionen; Diels-Alder reactions; Fungi; Indoles; Naturstoffe; Pathways; Strukturaufklärung
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.201509462

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.
Sieben neue prenylierte Indolalkaloide wurden aus A. taichungensis isoliert. Dieser Pilz erzeugt Alkaloide mit anti‐Bicyclo[2.2.2]diazaoctan‐Kern, während A. protuberus und A. amoenus syn‐Derivate herstellen. Die Strukturdiversität der von Tryptophan abgeleiteten Sekundärmetaboliten deutet auf stereochemisch und strukturell hoch entwickelte Synthesefunktionen für Sekundärmetaboliten in diesen orthologen Pilzen hin.