Banca de DEFESA: CARLOS HENRIQUE CORRÊA DOS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : CARLOS HENRIQUE CORRÊA DOS SANTOS
DATA : 19/10/2018
HORA: 13:00
LOCAL: Sala 50 do IQ
TÍTULO:

Secondary metabolites and evaluation of biological activities of Siolmatra brasiliensis (Cogn.) Baill. (Cucurbitaceae) and species from Ziziphus Mill. genus (Rhamnaceae).

PALAVRAS-CHAVES:

Siolmatra brasiliensis, Ziziphus, triterpenoids, cyclopeptide alkaloids antinociceptive activity, anti-glycation activity, antibacterial activity, cytotoxic activity

PÁGINAS: 200
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Orgânica
ESPECIALIDADE: Química dos Produtos Naturais
RESUMO:

dos Santos, Carlos Henrique Corrêa. Secondary metabolites and evaluation of biological activities of Siolmatra brasiliensis (Cogn.) Baill. (Cucurbitaceae) and species from Ziziphus Mill. genus (Rhamnaceae). 2018. 200p. Thesis (Ph.D. in Chemistry). Instituto de Química, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ. 2018.

The chromatographic procedures with the crude hydroethanolic stem extract of Siolmatra brasiliensis allied to the application of physical methods of organic analysis allowed the isolation and structural determination of twenty compounds, five of them are being described for the first time in the scientific literature. NMR experiments and HR-MS techniques of the natural products and some acetyl derivatives were used. The antinociceptive (in vivo) and anti-glycation (in vitro) activities of the extract and fractions of the species were evaluated. The crude extract showed antinociceptive activity close to the positive control (morphine) at 10 and 30 mg.kg^-1 and the ethyl acetate fraction showed antinociceptive effect higher than the control at concentrations of 30 and 100 mg.kg^-1. In the evaluation of the anti-glycation activity the crude extract showed similar activity to the control (aminoguanidine) at 0.5 mg.mL^-1 and the fraction in chloroform obtained results higher than the control at 0.5 and 0.25 mg.mL^-1.

Four species of Ziziphus were included in this study to evaluation of biological activities, Z. joazeiro and Z. glaziovii presented promising results of bacterial growth inhibition of Aliivibrio fischeri and Bacillus subtilis and all extracts showed significant cytotoxic activities against PC- 3 and HT-29 cell lines. The chromatographic procedures with the chloroform fraction of the Z. glaziovii methanol stem extract, allied to physical experiments of organic analysis allowed identification of seventeen compounds, seven of which are being described for the first time in scientific literature. The compounds were evaluated for antibacterial activity, where epigouanic acid and alphitolic acid showed good results against B. subtilis (IC₅₀ of 20 and 12 μM, respectively). The compounds presented up to the concentration of 10 µM none or weak cytotoxic effects. UHPLC-MS-MS analysis of the alkaloidal fraction of the stem extract of Z. joazeiro allowed the identification of eight type-Ib cyclopeptide alkaloids, the structures were suggested by proposal of mass fragmentation.

MEMBROS DA BANCA:
Externo à Instituição - ALESSANDRA LEDA VALVERDE - UFF
Interno - 1705075 - DOUGLAS SIQUEIRA DE ALMEIDA CHAVES
Externo à Instituição - GILDA GUIMARÃES LEITÃO - UFRJ
Externo à Instituição - JORGE MAURICIO DAVID - UFBA
Interno - 1221906 - LUCIANO RAMOS SUZART
Presidente - 6386421 - MARIO GERALDO DE CARVALHO