Balticols A-F, New Naphthalenone Derivatives with Antiviral Activity, from an Ascomycetous Fungus

Six new naphthalenone derivatives, balticols A-F (1-6, resp.) and the known metabolite altechromone A (8) were isolated from the AcOEt extract of the culture broth of fungal strain 222 belonging to the Ascomycota, which was found on driftwood collected at the coast of the Greifswalder Bodden, Baltic Sea, Germany. All structures were elucidated on the basis of NMR spectroscopic data and mass spectrometric analyses. The balticols were found to exhibit inhibitory activity against influenza virus A and herpes simplex virus. The most potent antiviral activity was observed for balticol E (5) with an IC50 value of 0.01 mu g/ml against Herpes simplex virus type 1.