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Master's Dissertation
DOI
10.11606/D.60.2003.tde-07082003-094230
Document
Author
Full name
Barbara Casellato Elias
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
Ribeirão Preto, 2003
Supervisor
Committee
Pupo, Monica Tallarico (President)
Lopes, Norberto Peporine
Vieira, Paulo Cezar
Title in Portuguese
"Estudo químico e atividades biológicas de extratos obtidos de culturas de Penicillium verrucosum Dierck"
Keywords in Portuguese
Penicillium verrucosum
Atividade tripanocida.
Metabólitos secundários
Abstract in Portuguese
A ausência de tratamento eficaz contra a doença de Chagas e Leishmaniose justifica a pesquisa de novas substâncias efetivas no controle destas doenças. As enzimas GAPDH de T. cruzi e a APRT de L. tarentolae são fundamentais para o ciclo de vida dos parasitas, representando alvos terapêuticos específicos que permitem a busca racional de agentes antiparasitários. As fontes naturais produzem grande diversidade estrutural em substâncias químicas com amplo potencial biológico. Espécies de Penicillium são conhecidas por produzir diversas classes de metabólitos secundários bioativos, incluindo atividade antiparasitária. A triagem com os 115 extratos brutos obtidos das culturas de P. verrucosum, indicou os extratos MeOH da massa micelial e AcOEt do fluido da cultura como os mais ativos no ensaio sobre T. cruzi. Estes extratos são oriundos do meio pré-fermentativo 24 horas e meio fermentativo Takeuchi 72 horas. Nos ensaios enzimáticos nenhum extrato apresentou inibição acima de 35%. As diferentes atividades biológicas e análises dos perfis químicos de extratos, via CLAE, demonstraram que a produção de metabólitos secundários varia em função das condições de cultivo do fungo. Dos extratos selecionados foram isolados ácidos graxos, triglicerídeos, manitol, a,a-trealose, glicerilfosfocolina e um alcalóide dicetopiperazínico, que até o momento parece não ter sido isolado de Penicillium ou outra fonte natural.
Title in English
Chemical study and biological activities of crude extracts obtained from different cultures of Penicillium verrucosum Dierck
Keywords in English
Penicillium verrucosum
Secondary metabolites
Tripanocidal activity
Abstract in English
The absence of an effective treatment for Chagas’ disease and Leishmaniasis stimulates the search for new active compounds. The enzymes GAPDH from T. cruzi and APRT from L. tarentolae are attractive targets for rational search of antiprotozoal agents, taking part in essential pathways of the pathogens. Natural products are rich in structural diversity and biological activities. Penicillium is known to produce different groups of bioactive secondary metabolites, including antiprotozoal activity. In the trypanocidal screening of the 115 crude extracts from different cultures of P. verrucosum, the MeOH extracts from the mycelium and EtOAc extratcs from the culture broth were the most activity. These extracts were obtained from 24h in a preculture and for an additional 72h in Takeuchi medium. In the enzymatic assays, the highest inhibitory activity was 35%. Besides the differences observed in the biological activities, the extracts showed different chemical profiles in HPLC analysis. So, the production of secondary metabolites by P. verrucosum is dependent on the culture conditions. The chemical study of the selected extracts led to the isolation of fatty acids, triacylglycerols, mannitol, a,a-threalose, glycerylphosphocholine and one diketopyperazine alkaloid. This alkaloid has not previously been reported from Penicillium or other natural source.
 
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01.Apresentacao.pdf (48.47 Kbytes)
02.Introducao.pdf (235.46 Kbytes)
03.Objetivos.pdf (21.03 Kbytes)
05.Resultados.pdf (3.19 Mbytes)
06.Conclusao.pdf (15.30 Kbytes)
08.Anexos.pdf (365.85 Kbytes)
Publishing Date
2003-09-11
 
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