Two new cyclopentanoids from the endophytic fungus Aspergillus sydowii associated with the marine alga Acanthophora spicifera

A marine-derived endophytic fungus, identified as Aspergillus sydowii was isolated from the inner tissue of the marine red alga Acanthophora spicifera. After mass cultivation of the fungus, chemical investigation afforded two new chlorinated 2,5-diarylcyclopentenones, which were named sydowin A and B. The structures of the new compounds were established on the basis of NMR spectroscopic (¹H, ¹³C, 1H detected direct, and long range ¹H-¹³C correlations) and mass spectrometric (ESI and FT-ICR-MS) data. Structurally related fungal compounds have hitherto only been described from higher basidiomycetes, but are characterized for the first time from an ascomycete in this study.