Endophytic fungi are microorganisms that live in intercellular plant tissue without causing apparent negative effects for the host. This group of fungi represents an important reservoir of worldwide fungal diversity and bioactive molecules. Our previous studies showed that the medicinal plants Copaifera pubiflora, Echinacea purpurea, Melocactus ernestii, Opuntia humifusa, Lafoensia pacari and Smallanthus sonchifolius shelter a diverse community of endophytic fungi. Additionally, our results suggest that the endophytic fungi community associate with those plants is prolific producers of different antifungal compounds. The aim of the present study was to examine the production of antifungal metabolites by endophytic fungi isolated from medicinal plants as an alternative to replace synthetic fungicides used in control phytopathogenic fungi. Susceptibility testing against phytopathogenic Colletotrichum species was performed using dichloromethane extract of endophytic fungi with final concentration of 160 μg/ml. Through the bioassay-guided fractionation were isolated the compounds (–)-5-methylmellein [Biscogniauxia mediterranea]; (–)-(3R)-8-hydroxy-6-methoxy-3,5-dimethyl-3,4-dihydroisocoumarin [B. mediterranea]; speciferone A [Phoma sp.]; cytochalasin H [Diaporthe miriciae]; cytochalasin J [D. miriciae]. Additionally, different endophytic fungi were able to produce antifungal fatty acids (linoleic, stearic, caproic, caprylic and palmitic acids, for example). Each compound was evaluated in a microtiter assay to determine the sensitivity of C. acutatum, C. fragariae, C. gloeosporioides, Fusarium oxysporum, Botrytis cinerea, Phomopsis obscurans, and P. viticola at the final concentrations of 75, 150, and 300 μM. The compounds displayed moderate antifungal activity against the phytopathogenic fungi species.

MycoSymbiosis: Antifungal activity against phytopathogenic fungi produced by endophytic fungi associated with medicinal plants from Brazil and United States

254th National Meeting (2017)

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