Seven new prenylated indole diketopiperazine alkaloids from holothurian-derived fungus Aspergillus fumigatus

Seven new prenylated indole diketopiperazine alkaloids, including compound 1, 3 spirotryprostatins C-E (2-4), 2 derivatives of fumitremorgin B (5 and 6), and 13-oxoverruculogen (7), have been isolated from the holothurian-derived fungus Aspergillus fumigatus, along with 12 known ones (8-19). The structures of the new compounds were determined on the basis of extensive spectroscopic data and amino acid analysis. All new compounds were evaluated for their cytotoxic activities on MOLT-4, A549, HL-60, and BEL-7420 cell lines by the MTT and SRB methods.