N-Acetylation of Aromatic Amines by the Soil Fungus Aspergillus japonicus (UFMS 48.136)

Background: Fungi can play an important role in environmental remediation. A key class of pollutants is the aromatic amines (AA) comprising dyes, drugs, pesticides and products originated from combustion and other industrial residues. The microbial N-acetylation is known to be a chief detoxifying mechanism for noxious AA. However, this transformation is not widely reported for fungi. Methods: The filamentous soil fungus Aspergillus japonicus (UFMS 48.136) when cultivated with six structurally different AA led to selective N-acetylation of all tested compounds in only 24 h of incubation. Culture medium and mycelia were both separated by filtration over celite and extracted with EtOAc. The solvent was evaporated and the crude extract was purified by column chromatography. Results: Six acetylated AA were obtained with yields between 15.9 to 76.1 %. The products were characterized by IR, 1H NMR, 13C NMR spectra and mass spectrometry. Conclusion: Considering that reports on fungal N-acetylation of xenobiotic AA are scarce, our discovery can contribute for new investigations in this important research field and open opportunities for new methods of environmental detoxification.