Fungi of the genus
Paracoccidioides
are responsible for paracoccidioidomycosis. The occurrence of drug toxicity
and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal
extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested
in a microdilution assay against
Paracoccidioides brasiliensis
Pb18. Approximately 18% (5) of the extracts showed
minimum inhibitory concentration (MIC) values ≤ 125.0 μg/mL. Among these, extract from the fungus UFMGCB
8030 demonstrated the best results, with an MIC of 15.6 μg/mL. This isolate was identified as
Aspergillus felis
(by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene
analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal
activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 μg/mL against
P.
brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract
was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography
(HPLC) and an antifungal assay using
P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass
spectrometry allowed us to identify the antifungal agents present in the
A. felis extracts cytochalasins. These results
reveal the potential of
A. felis as a producer of bioactive compounds with antifungal activity.