Dipteryx odorata (Aubl.) Willd. E Dipteryx magnifica (Ducke) Ducke (FABACEAE): caracterização fitoquímica quanto à presença de cumarina e atividades antifúngica e antibacteriana
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2017-01-25Autor
http://lattes.cnpq.br/2995856324286537
https://orcid.org/0000-0002-9891-3689
SOUSA, Bruna Cristine Martins de
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Dipteryx odorata (Aubl.) Willd. and Dipteryx magnifica (Ducke) Ducke belong to the Fabaceae family and are Neotropical trees originating in Central and South American countries. The fruits of D. odorata stand out in terms of commercial and phytotherapeutic potentials. The seeds for more than a century are commercialized by extractivists from the Amazon and, historically, they have been highly sought after for the extraction of coumarin (main active compound) to flavor tobacco pipes. Dipteryx magnifica, it lacks studies that detail its specific botanical description, chemical composition and biological activities, because this information was not found in the consulted literature. In this sense, the objective of this work was to evaluate the chemical profile of the ethanolic extracts of leaves, branches and fruits (bark, endocarp and seeds) of the species in relation to the presence of coumarin simple and its antimicrobial activity on fungi pathogenic to vegetables and bacteria pathogenic to humans. The extractions were carried out at the Laboratório de Pesquisa & Desenvolvimento de Produtos Naturais Bioativos (P&DBIO), UFOPA, using Soxhlet apparatus and having 96% P.A. ethanol. The total extraction period was 8 h for each procedure and the extracts were fractionated according to the biological activities presented. The chemical analyzes were carried out in the Divisão de Química Orgânica e Farmacêutica, no Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas (CPQBA), UNICAMP, by Thin Layer Chromatography (TLC) and by Gas Chromatography coupled to Mass Spectrometry (GC-MS). The antifungal tests were carried out at the Laboratório de Fitopatologia, UFOPA, in which the extracts were tested in five concentrations: 10%, 20%, 30%, 40% and 50%. Controls consisted of fungus growth only in potato-dextrose-agar medium (negative control) and in PDA culture medium with coumarin addition (positive control). As challengers we had: Cercospora longissima isolated from lettuce; three isolates of Fusarium spp. and Sclerotium rolfsii isolated from chili. The experiments were in DIC, in a factorial scheme, with four replications. The results were compared by the Skott-Knott test at 5% probability. Microbiological testing of MIC (Minimum Inhibitory Concentration) was performed at the Divisão de Microbiologia, CPQBA, UNICAMP, according to the recommendations of the M7-A6 protocol for bacteria (NCCLS, 2003). The microorganisms used in the assay were: Burkholderia cepacia (ATCC 25416); Escherichia coli (ATCC 11775); Pseudomonas aeruginosa (ATCC 13388) and Staphylococcus aureus (ATCC 6538). The extracts were weighed and then each sample was diluted in Mueller-Hinton broth to a concentration of 8 mg.mL-1, containing 10% DMSO (dimethylsulfoxide). The concentrations evaluated were: 2000; 1000; 500; 250; 125; 62.5; 31.25; 15.62; 7.81; 3.91 and 1.95 μg.mL-1 and as a control the antibiotic chloramphenicol - 0.5 mg.mL-1 solution was used. The bacteria contained in the microplates were incubated in a greenhouse at 36±1°C for 24 h and after that time 50 μL of 0.1% solution of 2,3,5-triphenyl-tetrazolium chloride (TTC) And re-incubated for a period of 3 h. The highest yields were obtained on the bark and seeds of the fruits of the species. 1,2-Benzopyrone was isolated and identified in the extracts of the seeds of D. odorata, and in the shells, in the endocarps, and in the seeds of D. magnifica. As for the antifungal action, it was verified that the coumarin isolated presented better action against the isolates obtained from Fusarium spp., and that the extracts of the endocarps of D. odorata and seeds of D. magnifica, provided the lowest growth averages for the phytopathogens tested. As for the antibacterial activity, extracts of D. odorata and D. magnifica obtained from the leaves, branches and seeds did not present bacteriostatic or bactericidal effect for the evaluated pathogens. However, the extracts of the shells and endocarps of the species presented bacteriostatic effect for E. coli in the highest concentration tested. Staphylococcus aureus was also sensitive to the action of D. magnifica bark extract at the concentration of 2.0 mg.mL-1; Confirmed sensitivity after the CBM test (Minimum Bactericidal Concentration). The species under study were promising for the use of their fruits, both for obtaining coumarin, and for alternative control of specific phytopathogens and antibacterial action. The extracts of the shells, endocarps and seeds of D. odorata and D. magnifica will be fractionated, chemically analyzed by TLC and GC-MS, and tested against fungi and sensitized bacteria.
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