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Thèse de Doctorat
DOI
10.11606/T.11.2018.tde-17072018-184806
Document
Auteur
Nom complet
Diana Fortkamp
Adresse Mail
Unité de l'USP
Domain de Connaissance
Date de Soutenance
Editeur
Piracicaba, 2018
Directeur
Jury
Lira, Simone Possedente de (Président)
Sass, Daiane Cristina
Angelis, Derlene Attili de
Pimenta, Eli Fernando
Titre en portugais
Metabólitos secundários produzidos por fungos endofíticos isolados de Anthurium alcatrazense e Begonia spp.
Mots-clés en portugais
Biofilme
Fungicida
Ilha de Alcatrazes
Mata Atlântica
Proteassoma
Resumé en portugais
Os produtos do metabolismo secundário, também conhecidos por produtos naturais, representam uma fonte inexplorada de compostos com atividade biológica. Os micro-organismos, entre eles os endófitos, são fontes promissoras de obtenção dessas substâncias. Assim sendo, essa pesquisa visou obter compostos de importância biotecnológica produzidos por fungos endofíticos isolados de folhas das plantas Anthurium alcatrazense, Begonia venosa e B. fischeri. Para isso, 5 linhagens de fungos endofíticos isolados dessas plantas (códigos P7BDA1F2, P8BDA1F1, AM29, D28 e D29) foram estudadas. A identificação desses micro-organismos foi realizada por meio de análises morfológicas e moleculares, revelando serem estas linhagens Hymenochaete-like, Trichoderma sp., Neopestalotiopsis sp., Aspergillus sp. e Diaporthe sp., respectivamente. A partir do extrato bruto de Hymenochaete-like (código P7BDA1F2) foram isolados os compostos 5,7-dimetoxiftalida e metil orselinato, os quais foram testados contra Leishmania (L.) infantum e alvo do proteassoma e não apresentaram atividade. A partir do extrato bruto de Trichoderma sp. (código P8BDA1F1) foram isolados os compostos trilongins BI-BIV. Estes apresentaram atividade inibitória ao fitopatógeno C. gloeosporioides, com MIC de 40, 320, 160 e 310 μM, respectivamente. As trilongins BI-BIV foram testadas contra a subunidade ChTL do proteassoma e apresentaram os valores de IC50 de 6,5 ± 2,7; 4,7 ± 1,8; 6,3 ± 2,2; e 2,7 ± 0,5 μM. Os compostos também foram testados ex vivo contra os amastigotas intracelulares de Leishmania (L.) infantum, mas não apresentaram seletividade. A partir do extrato bruto de Neopestalotiopsis sp. (código AM29), foi isolado um composto de massa molecular 366,0570 Da (que pode ser inédito na literatura), o qual apresentou atividade inibitória ao fitopatógeno P. sojae, com MIC de 312 μg mL-1. A partir dos extratos brutos de Aspergillus sp. e Diaporthe sp. foram isolados 9 compostos, cujas frações precursoras apresentaram atividade contra as bactérias formadoras de biofilme S. aureus e P. aeruginosa. Para a identificação desses compostos, análises adicionais precisam ser realizadas. Este é o primeiro relato do isolamento dos compostos 5,7-dimetoxiftalida e metil orselinato do basidiomiceto Hymenochaete-like. Também está sendo relatada pela primeira vez a atividade antifúngica das trilongins a C. gloeosporioides e contra o alvo do proteassoma, assim como o isolamento de um possível novo composto de Neopestalotiopsis sp. e sua atividade contra P. sojae.
Titre en anglais
Secondary metabolites produced by endophytic fungi isolated from Anthurium alcatrazense and Begonia spp.
Mots-clés en anglais
Atlantic forest
Biofilm
Fungicide
Island of Alcatrazes
Proteasome
Resumé en anglais
Secondary metabolism products, also known as natural products, represent an unexplored source of compounds with biological activity. Microorganisms, including endophytes, are promising sources of these substances. Thus, this research aimed to obtain compounds with biotechnological importance produced by endophytic fungi isolated from leaves of the plants Anthurium alcatrazense, Begonia venosa and B. fischeri. To this end, 5 endophytic fungal strains isolated from these plants (codes P7BDA1F2, P8BDA1F1, AM29, D28 and D29) were studied. The identification of these microorganisms was carried out by morphological and molecular analyzes, revealing that these strains are Hymenochaete-like, Trichoderma sp., Neopestalotiopsis sp., Aspergillus sp. and Diaporthe sp., respectively. From the crude extract of Hymenochaete-like (code P7BDA1F2) the compounds 5,7-dimethoxyphthalide and methyl orselinate were isolated, which were tested against Leishmania (L.) infantum and proteasome target and showed no activity. From the crude extract of Trichoderma sp. (code P8BDA1F1) the trilongins BI-BIV were isolated. These compounds presented inhibitory activity to the plant pathogen C. gloeosporioides, with MIC of 40, 320, 160 and 310 μM, respectively. The trilongins BI-BIV were tested against the ChTL subunit of the proteasome and showed IC50 values of 6.5 ± 2.7, 4.7 ± 1.8, 6.3 ± 2.2, 2.7 ± 0, 5 μM. The compounds were also tested ex vivo against the intracellular amastigotes of Leishmania (L.) infantum, but did not show selectivity. From the crude extract of Neopestalotiopsis sp. (code AM29), a compound with molecular mass 366.0570 Da (which can be unpublished in the literature) was isolated, which presented inhibitory activity to the plant pathogen P. sojae, with MIC of 312 μg mL-1. From the crude extracts of Aspergillus sp. and Diaporthe sp. 9 compounds were isolated, whose precursor fractions showed activity against the biofilm forming bacteria S. aureus and P. aeruginosa. For the identification of these compounds, additional analyzes need to be performed. This is the first report of the isolation of the compounds 5,7-dimethoxyphthalide and methyl orselinate from the basidiomycete Hymenochaete-like. The antifungal activity of trilongins to C. gloeosporioides and against the proteasome target is also being reported for the first time, as well as the isolation of a possible new compound from Neopestalotiopsis sp. and its activity against P. sojae.
 
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Date de Publication
2018-07-24
 
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