Novel chromone derivatives from the fungus Aspergillus versicolor isolated from the marine sponge Xestospongia exigua

From the marine Sponge Xestospongia exigua collected in Indonesia the fungus Aspergillus versicolor was isolated. Following cultivation in a seawater-based medium seven new angular tricyclic chromone derivatives (1-7) were obtained from the mycelia and culture filtrate. Compounds 2-7 contain an additional dihydropyran ring system which is replaced by a pyridine ring in 1. The structures of the new Natural Products were established on the basis of extensive one- and two-dimensional NMR spectroscopic studies (1H, 13C, COSY, HMQC, HMBC, NOE difference spectra) as well as on mass spectral analysis.