Antiproliferative Illudalane Sesquiterpenes from the Marine Sediment Ascomycete Aspergillus oryzae .

The new asperorlactone ( 1 ), along with the known illudalane sesquiterpene echinolactone D ( 2 ), two known pyrones, 4-(hydroxymethyl)-5-hydroxy-2 H -pyran-2-one ( 3 ) and its acetate 4 , and 4-hydroxybenzaldehyde ( 5 ), were isolated from a culture of Aspergillus oryzae , collected from Red Sea marine sediments. The structure of asperorlactone ( 1 ) was elucidated by HR-ESIMS, 1D, and 2D NMR, and a comparison between experimental and DFT calculated electronic circular dichroism (ECD) spectra. This is the first report of illudalane sesquiterpenoids from Aspergillus fungi and, more in general, from ascomycetes. Asperorlactone ( 1 ) exhibited antiproliferative activity against human lung, liver, and breast carcinoma cell lines, with IC ₅₀ values < 100 µM. All the isolated compounds were also evaluated for their toxicity using the zebrafish embryo model.