Fungal duel between Penicillium brasilianum and Aspergillus nomius results in dual induction of miktospiromide A and kitrinomycin A

Cocultivation of the fungi Penicillium brasilianum MST-FP1927 and Aspergillus nomius MST-FP2004 resulted in the reciprocal induction of two new compounds, miktospiromide A (1) from A. nomius and kitrinomycin A (2) from P. brasilianum. A third new compound, kitrinomycin B (3), was also identified from an axenic culture of P. brasilianum, along with the previously reported compounds austalide K (4), 17S-dihydroaustalide K (5), verruculogen (6), and fumitremorgin B (7). The structures of 1-3 were elucidated by detailed spectroscopic analysis and DFT calculations, while 4-7 were identified by comparison to authentic standards. The genome of A. nomius MST-FP2004 was sequenced, and a putative biosynthetic gene cluster for 1 was identified. Compound 2 showed activity against murine melanoma NS-1 cells (LD₉₉ 7.8 μM) and the bovine parasite Tritrichomonas foetus (LD₉₉ 4.8 μM).