Sargassopenillines A-G, 6,6-spiroketals from the alga-derived fungi Penicillium thomii and Penicillium lividum

Seven new 6,6-spiroketals, sargassopenillines A-G (1-7) were isolated from the alga-derived fungi Penicillium thomii KMM 4645 and Penicillium lividum KMM 4663. The structures of these metabolites were determined by HR-MS and 1D and 2D NMR. The absolute configurations of compounds 1, 5 and 6 were assigned by the modified Mosher's method and by CD data. Sargassopenilline C (3) inhibited the transcriptional activity of the oncogenic nuclear factor AP-1 with an IC50 value of 15 µM.