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Marine natural products: isolation and identification of unknown metabolites from endophytic fungi and cyanobacteria through chemical epigenetic elicitation and dereplication via molecular networking

Grant number: 10/17178-9
Support Opportunities:Scholarships in Brazil - Doctorate
Effective date (Start): January 01, 2011
Effective date (End): November 30, 2014
Field of knowledge:Physical Sciences and Mathematics - Chemistry
Principal Investigator:Hosana Maria Debonsi
Grantee:Rafael de Felício
Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
Associated scholarship(s):12/00246-7 - Chemical epigenetic modulation of marine cyanobacteria, BE.EP.DR


Marine natural products are pointed out as one of the most important sources of bioactive compounds for drug discovery. In this environment, organisms are in constantly interaction ecological through the production of secondary metabolites. Endophytic fungi and cyanobacteria represent groups of microorganisms that perform biosynthesis of substances with unique chemical features and potent biological activities. However, when removed from their natural habitat, these microbial beings generally lose their metabolic capacity through a phenomenon called gene silencing, in which biosynthetic genes are no longer transcribed due to reasons still undetermined. This genetic mechanism is brokered, among other factors, by the enzyme DNA methyltransferase (DNA-MT) and histone deacetylase (HDAC). Thus, their inhibitors have been used successfully to promote the elicitation of substances that would not be produced under laboratory conditions. Another important approach in the natural products research field have been dereplication based on the fragmentation (MS/MS) for the identification of substances or analogues. The molecular networking is a new approach in which data from mass spectrometry are grouped according to the similarities between the patterns of fragmentation, forming families of molecules, allowing rapid visualization of the chemical profile of several samples simultaneously. Thus, this work presents the isolation and identification of novel metabolites from endophytic fungi and cyanobacteria originating from the marine environment. For this purpose, epigenetic elicitation techniques were used in both groups of organisms and the molecular networks via dereplication was used in cyanobacteria. Endophytic fungi associated with red seaweed Bostrychia tenella were subjected to chemical and epigenetic studies. Xylaria sp. and Nigrospora oryzaestrains were cultured in solid medium rice, resulting in isolation of substance of cytochalasin D and a potentially novel derivative of griseofulvin. Penicillium decaturense strain was grown in PDB liquid medium resulting in the isolation of 10,11-deidrocurvularina and possible analogues. Experiments with epigenetic inhibitors(sodium butyrate and procaine) promoted the modulation of the chemical profile of this strain, to stimulate the production of metabolites not expressed under normal culture conditions. Moreover, Acremonium sp. produced various substances when grown inliquid medium under the influence of Czapek procaine, one of novel and potentiallyderived from the class of metabolites brevianamides. Organic fractions of the cyanobacteria Schizothrix sp., collected in Panama, were analyzed by LC-MS/MS and the data generated were used to create molecular networks. This study resulted in the identification of metabolites barbamide, hectochlorin, curacins A and D, curazolemalyngamide D acetate, dolastatin 10 and carmaphycin B. Also, analogs of curazole, dolastatin 10 and carmaphycins A and B have been proposed. Cyanobacteria Mooreaproducens JHB, collected in Jamaica, was grown under the influence of sodium butyrate, and produced two new proposed metabolites in accordance with the fragmentation data as being derived from jamaicamide and hectochlorin, in a sort of crossed biosynthesis. Therefore, this work corroborates marine endophytic fungi and cyanobacteria as promising for exploration of secondary metabolism. (AU)

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Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
DE FELICIO, RAFAEL; PAVAO, GABRIEL B.; DE OLIVEIRA, ANA LIGIA L.; ERBERT, CINTIA; CONTI, RAPHAEL; PUPO, MONICA T.; FURTADO, NIEGE A. J. C.; FERREIRA, ELTHON G.; COSTA-LOTUFO, LETICIA V.; YOUNG, MARIA CLAUDIA M.; et al. Antibacterial, antifungal and cytotoxic activities exhibited by endophytic fungi from the Brazilian marine red alga Bostrychia tenella (Ceramiales). REVISTA BRASILEIRA DE FARMACOGNOSIA-BRAZILIAN JOURNAL OF PHARMACOGNOSY, v. 25, n. 6, p. 641-650, . (10/17178-9, 05/53808-9)
DRUMOND CHEQUER, FARAH MARIA; LIZIER, THIAGO MESCOLOTO; DE FELICIO, RAFAEL; BOLDRIN ZANONI, MARIA VALNICE; DEBONSI, HOSANA MARIA; LOPES, NORBERTO PEPORINE; DE OLIVEIRA, DANIELLE PALMA. The azo dye Disperse Red 13 and its oxidation and reduction products showed mutagenic potential. TOXICOLOGY IN VITRO, v. 29, n. 7, p. 1906-1915, . (10/17178-9, 06/02505-9)
Academic Publications
(References retrieved automatically from State of São Paulo Research Institutions)
FELÍCIO, Rafael de. Marine natural products: isolation and identification of unknown metabolites from endophytic fungi and cyanobacteria through chemical epigenetic elicitation and dereplication via molecular networking. 2014. Doctoral Thesis - Universidade de São Paulo (USP). Faculdade de Ciências Farmacêuticas de Ribeirão Preto (PCARP/BC) Ribeirão Preto.

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