Anti-inflammatory prenylbenzaldehyde derivatives isolated from Eurotium cristatum

Two undescribed prenylbenzaldehyde derivatives, cristaldehydes A and B, and an undescribed quinone derivative, cristaquinone A, along with seven known compounds were isolated from the fungus Eurotium cristatum. The structures of undescribed compounds were determined by spectroscopic analysis including NMR, HR-ESIMS, and single-crystal X-ray diffraction. This is the first report of identification of a dibenzannulated 6,6-spiroketal derivative, cristaldehyde B, in a natural product. Cytotoxic and anti-inflammatory activities of all compounds were evaluated. Cristaldehyde A and cristaquinone A along with five known compounds showed significant anti-inflammatory activities with IC50 values in the range from 0.37 to 14.50 μM.