10-Norparvulenone is a fungal metabolite originally isolated fromMicrosphaeropsis.1It decreases viral sialidase activity in, and increases survival of, MDCK cells infected with the mouse-adapted influenza virus A PR 8 34 when used at a concentration of 1 μg ml. 1.Fukami, A., Nakamura, T., Kim, Y.P., et al.A new anti-influenza virus antibiotic, 10-norparvulenone from Microsphaeropsis sp. FO-5050J. Antibiot. (Tokyo)53(10)1215-1218(2000)