Apralactone A and a New Stereochemical Class of Curvularins from the Marine Fungus Curvularia sp

• Published in: European Journal of Organic Chemistry 2008-10, Vol.2008 (30), p.5085-5092
• Main Authors: Greve, Hendrik, Schupp, Peter J., Eguereva, Ekaterina, Kehraus, Stefan, Kelter, Gerhard, Maier, Armin, Fiebig, Heinz-Herbert, König, Gabriele M.
• Format: Article
• Language: English
• Subjects: Antitumor agents; Marine fungi; Natural products; Polyketides
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.200800522

Chemical investigations of the cytotoxic extract of the marine fungus Curvularia sp. (strain no. 768), isolated from the red alga Acanthophora spicifera, yielded the novel macrolide apralactone A (1), as well as the antipodes of curvularin macrolides 2–7. Compound 8, a dimeric curvularin was recognised as an artefact. The structures of 1–8 were elucidated by interpretation of their spectroscopic data (1D and 2D NMR, CD, MS, UV and IR). Apralactone A (1) is a 14‐membered phenyl acetic acid macrolactone, and the first such compound with a 4‐chromanone substructure. Compounds 1, 2, 4, 5 and 6 were found to be cytotoxic towards human tumor cell lines with mean IC50 values in the range of 1.25 to 30.06 μM. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) The novel macrolide apralactone A (1) was isolated from the marine fungus Curvularia sp. Apralactone A (1) is a 14‐membered phenyl acetic acid macrolactone, and the first such compound with a 4‐chromanone substructure. 1 and related compounds, which belong to the curvularin class, were evaluated for their cytotoxic activity towards human tumor cell lines.