Banca de QUALIFICAÇÃO: GABRIELLE MACEDO PEREIRA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : GABRIELLE MACEDO PEREIRA
DATA : 14/10/2016
HORA: 14:00
LOCAL: Sala Carl Peter von Dietrich - Depto. de Bioquímica - CB/UFRN
TÍTULO:

Bioprospecção de alcaloides tropânicos de Erythroxylum pungens O. E. Shulz   

PALAVRAS-CHAVES:

Caatinga Biome, Secondary metabolites, Erythroxylaceae, Cytotoxicity

PÁGINAS: 89
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

The Erythroxylaceae family comprises four genera with pantropical distribution which has Erythroxylum P. Browne as the most representative genre. Erythroxylum is characterized by production of tropane alkaloids which are known for their remarkable biological properties such as anesthetic, anticholinergic, antiemetic and anti-depressant activities. Recent studies have pointed out the Erythoxylum genre as a source of molecules with antitumor activity. Erythroxylum pungens O. E. Shulz is found in the Caatinga biome in northeastern Brazil. The potential of this species is still untapped regarding chemical studies and cytotoxic activity of these alkaloids. Thus, this study aims to investigate the Erythroxylum pungens alkaloids with cytotoxic potential. The extracts of leaf, stem, and root were prepared using exhaustive maceration with 96% ethanol and then subjected to acid-base extraction resulting in 3 enriched alkaloids fractions: FEP1, FEP2 and FEP3. The alkaloid EP01 (3- (2-methylbutyryloxy) tropane-6,7diol) was isolated by recrystallization from FEP1 and It was characterized by spectroscopic techniques. In addition, the compounds 3α-Isovaleryloxitropane-6β-ol and notropane (m / z 198) were also identified in FEP1. Meanwhile, the FEP3 fraction was fractionated by classical chromatography column using silica gel as stationary phase resulting in three fractions which only F3 fraction was submitted to further analysis. FEP1, FEP2 and F3 chemical profiles were characterized by LC / ESI-MS / MS showing fragmentation profiles similar to scopolamine, atropine and +/- hyoscyamine. In addition, FEP2 demonstrated fragmentation partner similar to cocaine, ecgonine and benzoylecgonine. FEP1, FEP2, F3, EP01 and two tropane alkaloid standards (atropine and scopolamine) were evaluated against tumor cell lines (HeLa, SiHa, PC3, 3T3 and 786-0). In conclusion, all samples tested except scopolamine showed significant inhibitory activities.

 

MEMBROS DA BANCA:
Presidente - 1549705 - ADRIANA FERREIRA UCHOA
Externo ao Programa - 1516627 - JULIANA ESPADA LICHSTON
Externo ao Programa - 1046922 - LEONARDO CAPISTRANO FERREIRA