Acremochlorin O and Other Prenylated Chlorophenol Antimicrobial Metabolites from the Fungus Acremonium sp. Strain MNA-F-1

Chemical investigation of the ethyl acetate extract of the fungus Acremonium sp., derived from the inner tissue of anise roots, led to the isolation and characterization of one new chlorinated compound, acremochlorin O (1), together with five related derivatives (2–6) and an alkaloidal metabolite, ilicicolin H (7). Structure elucidation of the isolated compounds was determined based on extensive 1D/2D NMR spectroscopic analyses and HR-ESI-MS measurements. The absolute configuration of acremochlorin O (1) was established using an electronic circular dichroism (ECD) experiment. All isolated compounds were evaluated for their antibacterial activity against Staphylococcus aureus, Escherichia coli and Mycobacterium tuberculosis, where several compounds revealed potent activities against tested Gram-positive strains.