A Study of the Metabolic Profiles of Penicillium dimorphosporum KMM 4689 Which Led to Its Re-Identification as Penicillium hispanicum

Changes in cultivation conditions, in particular salinity and temperature, affect the production of secondary fungal metabolites. In this work, the extracts of fungus previously described as Penicillium dimorphosporum cultivated in various salinity and temperature conditions were investigated using HPLC UV/MS techniques, and their DPPH radical scavenging and cytotoxicity activities against human prostate cancer PC-3 cells and rat cardiomyocytes H9c2 were tested. In total, 25 compounds, including 13 desoxyisoaustamide-related alkaloids and eight anthraquinones, were identified in the studied extracts and their relative amounts were estimated. The production of known neuroprotective alkaloids 5, 6 and other brevianamide alkaloids was increased in hypersaline and high-temperature conditions, and this may be an adaptation to extreme conditions. On the other hand, hyposalinity stress may induce the synthesis of unidentified antioxidants with low cytotoxicity that could be very interesting for future investigation. The study of secondary metabolites of the strain KMM 4689 showed that although brevianamide-related alkaloids and anthraquinone pigments are widely distributed in various fungi, these metabolites have not been described for P. dimorphosporum and related species. For this reason, the strain KMM 4689 was re-sequenced using the β-tubulin gene and ITS regions as molecular markers and further identified as P. hispanicum.