Transferring fungi to a deuterium-enriched medium results in assorted, conditional changes in secondary metabolite production

The incorporation of deuterium into organic substrates is known to alter the function of enzymes. Our study tested the extent to which deuterium enrichment would result in the modification of fungal secondary metabolite production. Eight fungal cultures we tested were marked by changes in natural product production. Work-up of one Aspergillus sp. grown under deuterium-enrichment conditions resulted in an active fungal extract against MRSA, which was not observed in the crude extract from the fungus grown under non-deuterium enriched conditions. An assortment of NMR and mass spectrometry experiments enable us to identify isotope-labelled brevianamide F (1), stephacidin A (2), notoamide D (3), notoamide L (4), notoamide C (5), and bacterial inhibitor pigmentosin A (6). 1 and 3 – 6 have not been previously observed from this fungal isolate. Therefore, we propose that deuterium-enrichment might offer an effective method for further expanding a fungus's chemical diversity potential.