Banca de QUALIFICAÇÃO: SARA FREITAS DE SOUSA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : SARA FREITAS DE SOUSA
DATA : 25/04/2019
HORA: 09:00
LOCAL: Sala 117 - Unidade Amazônia
TÍTULO:

PHYTOCHEMICAL, ANTIOXIDANT AND BIOLOGICAL ACTIVITY STUDY OF WOOD RESIDUE CONSTITUENTS OF THE Hymenaea sp. 

PALAVRAS-CHAVES:

Jatobá. Secondary metabolites. Antimicrobian activity.

PÁGINAS: 48
GRANDE ÁREA: Outra
ÁREA: Ciências Ambientais
RESUMO:

The use of wood residues of the genus Hymenaea (family Fabaceae) may be an opportunity to develop new products due to it its chemical constitution, bioactive compounds, and biological properties. The objective of this study was to determine the phytochemical, antimicrobial and antioxidant activity of Hymenaea sp. Forest residues were obtained from a managed area near to Santarém city, Pará, Brazil. The sawdust was oven-dried at 40 ° C for 96 h then extracted the secondary metabolites with ethanol in Soxhlet apparatus. The phytochemical characterization of Hymenaea sp. extracts were obtained from Thin-layer Chromatography (CCD) and Gas Chromatography coupled to Mass Spectrometry (GC-MS). The antioxidant capacity was determined by the DPPH method (2,2-diphenyl-1-picrylhydrazine), and absorbance measured in a spectrophotometer at 516 nm. The total amount of phenolic compounds was determined by the Folin-Ciocalteau spectrophotometric method. The calculation of the results was based on an analytical curve with 7 points (10 - 80 μg.mL^-1) of gallic acid standard (y = 83,532x - 0,5777 and R2 = 0,99) at 740 nm and the result expressed in μg of gallic acid equivalent (EAG) per g of dry matter. The total flavonoid content was performed by spectrophotometric method and the results were calculated based on a seven-point analytical curve (5 - 80 μg.mL^-1) of the Rutine standard (y = 218,15x-1,7073 and R2 = 0.99) at 420 nm and the result expressed in μg equivalent to Routine (ERT) per g of dry matter. Minimum inhibitory concentration (MIC) and Fungicidal Concentration / Minimum Bactericide (CFM) were determined by microdilution in broth against fungi and Gram-positive and Gram-negative bacteria. The classes of compounds present in the Hymenaea extract detected by CCD and GC-MS were fatty acids, terpenes, phytosteroids and flavonoids. An antioxidant potential with IC50 of A1 = 10.61 ± 0.38 μg.mL-1, A2 = 11.03 ± 0, 57 μg.mL^-1, A3 = 11.85 ± 0.64 μg.mL^-1 against the DPPH radical for the extract of the jatobá residue. The determined values of phenolics were considered to be high, presenting values of A1 = 0.87 ± 0.02 μEAG.μg^-1, A2 = 0.74 ± 0.02 μEAG.μg^-1 and A3 = 0.66 ± 0, 03 μEAG.μg^-1. The results also demonstrated high levels of flavonoids in the samples, A1 = 0.146 ± 0.0005; A2 = 0.093 ± 0.002; and A 3 = 0.199 ± 0.006 (μg ER mL^-1). On the antimicrobial activity, it was verified that the ethanolic extract of Jatobá was efficient for the tested pathogens, to which the greater efficiency was verified in Candida kruzei in the concentration of 62,5 µg.mL^-1. The antimicrobial and antioxidant potential of the jatobá extract may be related to its chemical constitution andthe influence of these compounds on their biological activity. Frequently, this extract is treated as a residue however it does have great potential of utilization.

MEMBROS DA BANCA:
Externo ao Programa - 1782945 - DENISE CASTRO LUSTOSA
Externo ao Programa - 1776289 - ELAINE CRISTINA PACHECO DE OLIVEIRA
Interno - 1520271 - JOAO RICARDO VASCONCELLOS GAMA
Presidente - 152.758.687-15 - LAURO EUCLIDES SOARES BARATA - UFOPA