Acremine G, dimeric metabolite from cultures of Acremonium byssoides A20(1)

A new dimeric fungal metabolite, racemic acremine G, was isolated from cultures of the fungus Acremonium byssoides A20, along with the known acremines A-F. Its structure was elucidated by NMR spectroscopy and X-ray crystallography. A possible biosynthetic pathway is discussed. Acremine G mildly inhibited the growth of sporangia of Plasmopara viticola.