Banca de QUALIFICAÇÃO: VÍCTOR DE CARVALHO MARTINS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : VÍCTOR DE CARVALHO MARTINS
DATA : 17/12/2019
HORA: 09:30
LOCAL: Sala 50 do Pavilhão de Química
TÍTULO:

DEREPLICATION BY BIOGUIDED ASSAYS OF NEW SUBSTANCES OF GENRE Myrcia FOR THE TREATMENT OF ALZHEIMER'S DISEASE

PALAVRAS-CHAVES:

Special metabolites; Myrcia; dereplication; bioguided essays; HPLC-DAD / MS; Alzheimer's disease

PÁGINAS: 20
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Orgânica
ESPECIALIDADE: Química dos Produtos Naturais
RESUMO:

Intracellular redox balance is an important parameter for eukaryotic cell metabolism. Reactive oxygen species (ROS) tend to be produced and can cause oxidative stress especially when endogenous antioxidant agents, such as glutathione, have impaired homeostasis. Changes in the ratio of reduced to oxidized glutathione (GSH / GSSG) are being related to the onset of age-related degenerative diseases such as Alzheimer's disease (AD). AD affects older individuals, and is currently the most common form of dementia and is expected to reach over 131.5 million individuals worldwide by 2050. Phytochemical research with acceleration by biochemical tests is an important dereplication tool for research for new substances with antioxidant potential in vivo. Taking into account the extensive Brazilian biodiversity, different taxa can be studied with this strategy, as the genus Myrcia, already reported in the literature by the presence of phenolic substances among nonvolatile components of its leaves and still possessing some endemic species of the Atlantic Forest. of Rio de Janeiro not studied. The objective of this project is to isolate new substances with antioxidant potential for the treatment of AD through the use of dereplication in leaves and fruits of the genus Myrcia. Plant material for the species M. amazonica, M. ovata and M. racemosa will be collected in collaboration with Professor Dr. Marcelo da Costa Souza (ICBS-UFRRJ) in preserved areas of the Atlantic Forest of Rio de Janeiro. The drying of the leaves and fruits will be performed, respectively, at room temperature and by lyophilization, with serial extraction being performed by mechanical stirring for 1h with solvents in increasing polarity (hexane, dichloromethane, ethyl acetate and methanol). The in vivo antioxidant assay will be carried out through a cell viability study and hydrogen peroxide-induced oxidative stress with two yeast strains of Saccharomyces cerevisiae (control strain BY4741; and Dgsh1, without the presence of the gene g-glutamylcysteine synthetase responsible by the limiting step of glutathione synthesis). For the most promising extracts, the purification and isolation of new substances will be performed by classical or instrumental chromatographic techniques (silica gel open column, HPLC) and the characterization by spectroscopic methods such as 1H and 13C NMR (1D and 2D). , high resolution mass spectrometry and UV-Visible spectroscopy. New in vivo antioxidant assays will be performed with the isolated substances. In addition, the extracts will complement the determination by HPLC-DAD of the profile of phenolic substances (phenolic acids, flavonoids and, in particular, anthocyanins) and the capture of synthetic organic radicals such as DPPH. and ABTS. +. The bioguided study is expected to contribute to the discovery of new substances with antioxidant potential in the genus Myrcia, enabling the use of these substances in future clinical studies of Alzheimer's disease.

MEMBROS DA BANCA:
Presidente - 2181682 - MARCIA CRISTINA CAMPOS DE OLIVEIRA
Interna - 1681790 - CRISTIANE MARTINS CARDOSO DE SALLES
Externa à Instituição - MANUELA CRISTINA PESSANHA DE ARAÚJO SANTIAGO - EMBRAPA