Asperteramide A, an Unusual N-Phenyl-Carbamic Acid Methyl Ester Trimer Isolated from the Coral-Derived Fungus Aspergillus Terreus

Asperteramide A, an unusual N-phenyl-carbamic acid methyl ester trimer, was isolated and identified from the coral-derived fungus Aspergillus terreus. The deceptive and indistinguishable NMR signals caused by three N-phenyl-carbamic acid methyl ester subunits located in different spatial environments created great challenge for the identification of its planar structure, but recrystallization ultimately afforded a suitable crystal for the X-ray diffraction experiment, which enabled its final structure determination. The plausible biosynthetic pathway of 1 mainly involved in the successive Friedel-Crafts reactions. Additionally, compound 1 showed significant antibacterial activity against seven microbial pathogens [ESBL-producing Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, Candida albicans] with MIC values ranging from 2 to 64 mu g/mL.