Estudo químico e biotecnológico de fungos endofíticos associados a Calea pinnatifida (Asteraceae) buscando compostos bioativos e de ação antimicrobiana
Data
2024-10-11
Autores
Fernandes, Bianca Barna 
Orientadores
Sartorelli, Patricia
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Os fungos endofíticos são microrganismos que vivem internamente nas plantas, geralmente sem causar danos ao hospedeiro, estabelecendo relações simbióticas que podem resultar na produção de compostos bioativos com ampla aplicabilidade. Este estudo focou na análise de fungos endofíticos isolados de Calea pinnatifida, uma planta medicinal conhecida por suas propriedades terapêuticas, visando avaliar o potencial antimicrobiano dos metabólitos produzidos por esses microrganismos e explorar seu arsenal enzimático na biotransformação de compostos. Foram isolados 23 fungos endofíticos a partir de caules e folhas de C. pinnatifida, os quais foram cultivados e identificados como pertencentes aos gêneros Colletotrichum, Hypomontagnella, Neopestalotiopsis, Nigrospora e Annulohypoxylon. Partes aéreas da planta, além dos fungos isolados, foram submetidos a extração de seus metabólitos, e o perfil químico resultante foi analisado por técnicas cromatográficas e espectroscópicas, associadas a ferramentas de desreplicação e caracterização de compostos. As análises revelaram uma grande diversidade química no metabolismo dos fungos endofíticos, com destaque para derivados de ácido tetrônico, como o Nudulisporácido A e, pela primeira vez descrito, o Nodulisfuranol isolados de Hypomontagnella barbarensis. A desreplicação dos extratos da planta indicou a presença de lactonas sesquiterpênicas e ácidos fenólicos, compostos descritos previamente na literatura. Adicionalmente, os extratos dos fungos endofíticos foram testados quanto à atividade antimicrobiana, utilizando métodos de difusão em disco e determinação da concentração inibitória mínima, destacando-se os extratos de Colletotrichum karstii e Hypomontagnella barbarensis, que apresentaram resultados promissores de inibição contra S. aureus, S. cerevisiae e C. albicans. Os fungos também foram induzidos a biotransformar limoneno, apenas 3 deles (Colletotrichum karstii e Neopestalotiopsis clavispora) demonstraram seu potencial enzimático no processamento desse substrato, transformando o limoneno em produtos como o limoneno-1,2-epóxido e posteriormente limoneno-1,2-diol, seguindo a mesma rota de conversão descrita em literatura, realizada pela bactéria Rhodococcus erythropolis. Assim, o estudo reforça a importância de explorar fungos endofíticos como fontes valiosas de novos compostos bioativos, com potencial para aplicações clínicas.
Endophytic fungi are microorganisms that live within plants, usually without causing harm to the host, establishing symbiotic relationships that can result in the production of bioactive compounds with broad applicability. This study focused on the analysis of endophytic fungi isolated from Calea pinnatifida, a medicinal plant known for its therapeutic properties, aiming to evaluate the antimicrobial potential of metabolites produced by these microorganisms and explore their enzymatic arsenal in compound biotransformation. Twenty-three endophytic fungi were isolated from the stems and leaves of C. pinnatifida, which were cultivated and identified as belonging to the genera Colletotrichum, Hypomontagnella, Neopestalotiopsis, Nigrospora, and Annulohypoxylon. Aerial parts of the plant, as well as the isolated fungi, were subjected to metabolite extraction, and the resulting chemical profile was analyzed using chromatographic and spectroscopic techniques, associated with dereplication and compound characterization tools. Analyses revealed a high chemical diversity in the metabolism of endophytic fungi, with a highlight on tetronic acid derivatives such as Nodulisporacid A and, for the first time reported, Nodulisfuranol isolated from Hypomontagnella barbarensis. Dereplication of plant extracts indicated the presence of sesquiterpene lactones and phenolic acids, compounds previously reported in the literature. Additionally, endophytic fungal extracts were tested for antimicrobial activity using disk diffusion and minimum inhibitory concentration methods, with extracts from Colletotrichum karstii and Hypomontagnella barbarensis showing promising inhibition results against S. aureus, S. cerevisiae, and C. albicans. The fungi were also induced to biotransform limonene, and only three of them (Colletotrichum karstii and Neopestalotiopsis clavispora) demonstrated enzymatic potential in processing this substrate, converting limonene into products such as limonene-1,2-epoxide and subsequently limonene-1,2-diol, following the same conversion pathway described in the literature for the bacterium Rhodococcus erythropolis. Thus, the study reinforces the importance of exploring endophytic fungi as valuable sources of new bioactive compounds with potential for clinical applications.
Endophytic fungi are microorganisms that live within plants, usually without causing harm to the host, establishing symbiotic relationships that can result in the production of bioactive compounds with broad applicability. This study focused on the analysis of endophytic fungi isolated from Calea pinnatifida, a medicinal plant known for its therapeutic properties, aiming to evaluate the antimicrobial potential of metabolites produced by these microorganisms and explore their enzymatic arsenal in compound biotransformation. Twenty-three endophytic fungi were isolated from the stems and leaves of C. pinnatifida, which were cultivated and identified as belonging to the genera Colletotrichum, Hypomontagnella, Neopestalotiopsis, Nigrospora, and Annulohypoxylon. Aerial parts of the plant, as well as the isolated fungi, were subjected to metabolite extraction, and the resulting chemical profile was analyzed using chromatographic and spectroscopic techniques, associated with dereplication and compound characterization tools. Analyses revealed a high chemical diversity in the metabolism of endophytic fungi, with a highlight on tetronic acid derivatives such as Nodulisporacid A and, for the first time reported, Nodulisfuranol isolated from Hypomontagnella barbarensis. Dereplication of plant extracts indicated the presence of sesquiterpene lactones and phenolic acids, compounds previously reported in the literature. Additionally, endophytic fungal extracts were tested for antimicrobial activity using disk diffusion and minimum inhibitory concentration methods, with extracts from Colletotrichum karstii and Hypomontagnella barbarensis showing promising inhibition results against S. aureus, S. cerevisiae, and C. albicans. The fungi were also induced to biotransform limonene, and only three of them (Colletotrichum karstii and Neopestalotiopsis clavispora) demonstrated enzymatic potential in processing this substrate, converting limonene into products such as limonene-1,2-epoxide and subsequently limonene-1,2-diol, following the same conversion pathway described in the literature for the bacterium Rhodococcus erythropolis. Thus, the study reinforces the importance of exploring endophytic fungi as valuable sources of new bioactive compounds with potential for clinical applications.