Banca de DEFESA: LUCAS DE OLIVEIRA PIRES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : LUCAS DE OLIVEIRA PIRES
DATA : 27/03/2019
HORA: 13:00
LOCAL: PQ-Sala Prof Otto Gottilieb -Sala 50
TÍTULO:

Isolation and characterization of phenolic compounds from Brazilian green propolis with antiparasitic activity

PALAVRAS-CHAVES:

polyphenolics, antioxidant, Artepillin C, trypanocidal activity, biomarker

PÁGINAS: 100
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Orgânica
ESPECIALIDADE: Química dos Produtos Naturais
RESUMO:

Propolis is a resinous natural products elaborated by honeybees from different parts of plants, such as shoots and flowers. Its chemical composition is very complex and depends on factors such as climate, seasonality, soil, vegetation and also the bee species. Propolis has currently been identified as na importante source of bioactive compounds due to its high biological potential, with anti-inflammatory, antibacterial, antitumoral, antiparasitic and antioxidant activities. In this work, ethanolic and n-hexanic extracts were prepared from three samples of green propolis obtained in different regions of Rio de Janeiro. The quality of these extracts were evaluated using colorimetric methods for the determination of the total phenolic content – total phenolic and flavonoid contents – and also the antioxidant capacity was evaluated by capturing organic free radicals (DPPH and ABTS), as well as the ferric reducing antioxidant power (FRAP). The qualitative chemical profile of the extracts was evalutated through CLAE-DAD analisys, and the influence of the solvente polarity on the extraction profile was studied. The bioactive compounds 3,5-diprenyl-4-hydroxycinamic acid (Artepillin C), 3-prenyl-4-[(3-phenylpropanoil)-oxy]-cinnamic acid (Baccharin) and 2,2-dimethyl-8-prenylcroman-5-propenoic acid were isolated from the n-hexane exrtract by two chromatographic steps: fracionation of crude extract using the mixture of solventes chloroform/acetone in increasing gradiente concentration, followed by purification of fractions of interest by HPLC-UV in semipreparative scale, using the mixture methanol/water in increasing gradiente concentration. All the isolated constituents were characterized by NMR (1H and 13C), UV spectra and CG-MS techniques, and the contente of these componentes in the crude extract was quantified through HPLC-DAD in reverse phase. The antiparasitic activity of green propolis and its active principles was evaluated against amastihote and tripomastigoe forms of Trypanosoma cruzi, the parasite responsible for causing Chagas’ disease. 

MEMBROS DA BANCA:
Presidente - 1177598 - ROSANE NORA CASTRO
Interno - 2181682 - MARCIA CRISTINA CAMPOS DE OLIVEIRA
Externo à Instituição - ROBERTO CARLOS CAMPOS MARTINS - UFRJ
Externo à Instituição - CLAUDIA MORAES DE RESENDE
Externo à Instituição - DAVYSON DE LIMA MOREIRA