Antifungal activity of extracts from Atacama Desert fungi against
Paracoccidioides brasiliensis and identification of
Aspergillus felis as a promising source of natural bioactive
compounds |
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Authors: | Graziele Mendes Vívian N Gon?alves Elaine M Souza-Fagundes Markus Kohlhoff Carlos A Rosa Carlos L Zani Betania B Cota Luiz H Rosa Susana Johann |
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Institution: | 1.Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Microbiologia, Belo Horizonte, MG, Brasil;2.Fundação Oswaldo Cruz, Centro de Pesquisa René Rachou, Laboratório de Química de Produtos Naturais, Belo Horizonte, MG, Brasil;3.Universidade Federal de Minas Gerais, Departamento de Fisiologia e Biofísica, Belo Horizonte, MG, Brasil |
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Abstract: | 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. |
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Keywords: | rock-inhabiting fungi Atacama Desert Paracoccidioides brasiliensis antifungal Aspergillus felis |
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