Incarnal. A new antibacterial sesquiterpene from Basidiomycetes

A new sesquiterpene, incarnal, was isolated from culture fluid of Gloeostereum incarnatum (Japanese name: Nikawaurokotake). Incarnal inhibited the growth of gram-positive bacteria at 6.25-12.5 micrograms/ml. The structure of incarnal has been determined to be (1-hydroxy-2,10,10-trimethyl)-3-methylene- tricyclo[6.3.0.0(2.6)]undec-5,7-diene-4,9-dione by X-ray diffraction and spectroscopic methods.