Prenylated quinolinone alkaloids and prenylated isoindolinone alkaloids from the fungus Aspergillus nidulans

Two undescribed prenylated quinolinone alkaloids, aspoquinolones E and F, and three undescribed prenylated isoindolinone alkaloids aspernidines F–H, were isolated from the fungus Aspergillus nidulans. Their structures and configurations were elucidated based on spectroscopic analyses and ECD spectra. Aspoquinolones E and F possess a C10 moiety with an unusual 2,2,4-trimethyl-3oxa-bicyclo[3.1.0]hexane unit, and aspernidines F–H own a C15 side chain. These compounds were evaluated for cytotoxic activities against five human cancer cell lines, compounds 1 and 5 exhibited strong inhibitory activities against A-549 and SW-480 cells with IC50 values of 3.50 and 4.77 μM, respectively.