Antroalbocin A, an Antibacterial Sesquiterpenoid from Higher Fungus <i>Antrodiella albocinnamomea</i>

Antroalbocin A (<b>1</b>), a sesquiterpenoid possessing a bridged tricyclic system, was isolated from cultures of the higher fungus <i>Antrodiella albocinnamomea</i> (Basidiomycota). The structure with the absolute configuration was determined by extensive spectroscopic methods and single-crystal X-ray diffraction. A plausible biosynthetic pathway for <b>1</b> was proposed. Compound <b>1</b> was found to inhibit <i>Staphylococcus aureus</i> with an MIC value of 169 μM.