Azaphilone pigments and macrodiolides from the coprophilous fungus Coniella fragariae

Abstract

Two azaphilone pigments (1 and 2), two dihydrobenzofurans (3 and 4), two macrodiolides (5 and 6), and a dimeric alkyl aromatic constituent (7) were isolated from the goose dung-derived fungus Coniella fragariae. Compounds 1-3 proved to be new natural products. Coniellins H and I (1 and 2) feature a tetracyclic core and an aldehyde group at C-5, which is unusual for azaphilone derivatives. The X-ray structure of pyrenophorin (5) is reported for the first time. Pyrenophorin (5) showed strong cytotoxicity against several cancer cell lines with IC₅₀ values ranging from 0.07 to 7.8 μM.

Keywords: Azaphilones; Coniella fragariae; Cytotoxicity; Pyrenophorin.