Prenylated Indole Diketopiperazines from the Marine-Derived Fungus Aspergillus versicolor

Seven new prenylated indole diketopiperazines, versicamides A-G (1-7) and a novel chemical derivative from 7, versicamide H (8), along with three known analogic diketopiperazines (9-11) were obtained from the marine-derived fungus Aspergillus versicolor HDN08-60. Their structures were determined by spectroscopic techniques, including 2D NMR, ECD calculations, and single-crystal X-ray diffraction analysis, together with the assistance of further chemical conversions. The cytotoxicities of 1-8 were tested against the HeLa, HCT-116, HL-60, and K562 cell lines, but only 8 exhibited moderate activity against HL-60 cells, with an IC50 value of 8.7 mu M. Further investigation with target screening showed that 8 exhibited selective PTK inhibitory activities.