Banca de DEFESA: DEBORAH PELOSI SESSA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : DEBORAH PELOSI SESSA
DATA : 18/12/2020
HORA: 09:00
LOCAL: por participação remota
TÍTULO:

Molecular dereplication and antiparasitic activity evaluation of Baccharis sphenophylla and Baccharis lateralis (Asteraceae) extracts

PÁGINAS: 157
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Orgânica
ESPECIALIDADE: Química dos Produtos Naturais
RESUMO:

Belonging to Asteraceae, with about 400 species originally distributed in all America, only 20% of species from the Baccharis genus were chemically studied. The major compounds found in this genus are flavonoids and diterpenes, which are considered to be the metabolites responsible for the diverse attributed biological activities. In continuation with our previous studies with Baccharis, two species from this genus, B. sphenophylla (BSM) and B. lateralis (BLM), were collected and their molecular fingerprints were investigated, through UPLC/DAD-ESI/HRMS/MS, since the chemical composition of their non-volatile extracts is still unreported. Besides that, the anti-parasitic potential of BLM and BSM extracts were also investigated against trypomastigote forms of T. cruzi parasites. The chemical investigation of BSM and BLM extracts evidenced 18 and 15 compounds respectively, most belonging to the flavonoid group. Among these, the flavonoids sakuranetin (27), apigenin (25) and the metabolites 5-methoxysalicylic acid (6) and urocanic acid (3) stand out in majority for BLM, while gardenin A (16), 6-methoxyluteolin (10) and 5-methoxysalicylic acid (6) for BSM. By means of the anti-parasitic potential, against trypomastigote forms of Trypanosoma cruzi, IC50 values were defined as 27.2 μg/mL and 16.9 μg/mL, for BSM and BLM respectively. Against mammalian cells (NCTC), neither extract presented cytotoxicity at the maximum tested concentrations (CC50 > 200 μg/mL). Therefore, the selectivity index (SI) of both extracts was calculated (CC50/IC50 ratio) as being 7.3 for BSM and 11.8 for BLM while the benznidazole presents SI > 36.4. The greater anti-parasitic potential of BLM, when compared to BSM, may be due to the presence of the flavonoids 27 and 25, since previous studies attribute the anti-T. cruzi activity to these compounds [2]. On the other hand, for the major flavonoids found in BSM, 6 was not active against T. cruzi [4], and no studies were found for compound 16. From this work, we conclude that the study of plant metabolomics using hyphenated techniques allows for a precise analysis of metabolites, avoiding wasted time isolating known bioactive compounds. Therefore, it is an excellent strategy for the chemical prospection of chemically unknown plant species.

 

 

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1623577 - JOAO HENRIQUE GHILARDI LAGO
Membro Titular - Examinador(a) Interno ao Programa - 3050857 - CELIO FERNANDO FIGUEIREDO ANGOLINI
Membro Titular - Examinador(a) Externo ao Programa - 1675708 - DANIELE RIBEIRO DE ARAUJO
Membro Titular - Examinador(a) Externo ao Programa - 297.424.378-90 - THAIS ALVES DA COSTA SILVA
Membro Titular - Examinador(a) Externo à Instituição - MARCELO JOSE PENA FERREIRA - USP
Membro Suplente - Examinador(a) Interno ao Programa - 1762430 - DALMO MANDELLI
Membro Suplente - Examinador(a) Externo à Instituição - JOSUE DE MORAES - UNG
Membro Suplente - Examinador(a) Externo à Instituição - PAULETE ROMOFF