Banca de DEFESA: GABRIELLE MACEDO PEREIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : GABRIELLE MACEDO PEREIRA
DATA : 25/08/2017
HORA: 14:00
LOCAL: Auditório do Departamento de Pediatria
TÍTULO:

Erythroxylum pungens O. E. Shulz: total proteome and bioprospection of tropane alkaloids

PALAVRAS-CHAVES:

Erythroxylaceae, Alkaloids, biome Caatinga, Proteomics, Environmental stresses

PÁGINAS: 158
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

Caatinga is an exclusive brazilian biome, marked by semi-arid climate, hot, lack of rain, high evaporation, strong insolation all year round, shallow and Stony soils. This biome stands out for the high endemism index and scientific unfamiliarity. Plants show evolution of intrinsic mechanisms of external environmental signals perception and their respectives metabolic responses in order to survive in this environment with peculiar edaphoclimatic conditions. These responses may modify the secondary metabolites profile, increasing or decreasing the amount and even modifying their profile. This can be interesting in the metabolites used for medicinal purposes. Erythroxylum pungens, which has unexplored potential, is outstanding in Caatinga biome as bioactive alkaloids source. Thus, the objective of this work was to investigate total proteome and metabolic fingerprint of E. pungens besides tropane alkaloids bioprospection with cytotoxic potential evaluation. It was possible to identify, by mass spectrometry, seven known tropane alkaloids; 3-(2-methylbutyryloxy)tropan-6, 7-diol as well as 3-(2-methylbutyryloxy)tropan-6, 7-diol were isolated and characterized by 1D and 2D NMR for the first time. N,N-Dimethyl-1-H-indol-3-ethanamine was isolated and characterized from roots. In addition, the assay against five cell lines indicated a selective potential of 3-(2-methylbutyryloxy)tropan-6, 7-diol against prostate tumor cells. This result was reinforced by docking studies. Iit was possible to identify 1746 proteins in the leaves, 1779 in the stem and 1026 in the root of E. pungens. Through the recovery of the GO terms, it was possible to evaluate processes in which these proteins are involved, verifying the same process profile for three organs of E. pungens, with emphasis on biotic, abiotic, chemical stress responses, as well as responses to oxidative stress. Were observed significant proteins levels involved in photosynthesis of E. pungens leaves, photorespiration, as well as many proteins related to stress responses: proteins from 14-3-3 family, peroxidases, catalases, superoxide dismutase and shock proteins, which can also act on protein turnover. Five proteins homologous to tropinone reductase were still identified, and the study of alkaloid production in all organs suggested that even under chronic stress conditions, E. pungens maintains the production of these special metabolites. Finally, in E. pungens in water stress by irrigation suspension in greenhouse, it was observed that this species invest in the increase of proteins related to the responses to water stress, it significantly increases free proline content in cytosol which act as an important osmoprotector. Furthermore, the plant maintains alkaloids production that appear to be more related to development stage of the plant than stress condition in which it is inserted. The results of this work seek to contribute to knowledge of E. pungens phytochemistry and physiology, as well as to promote the species and consequently conservation of Caatinga biome.

MEMBROS DA BANCA:
Presidente - 1871916 - RAQUEL BRANDT GIORDANI
Interno - 1549705 - ADRIANA FERREIRA UCHOA
Interno - 1228866 - EDUARDO LUIZ VOIGT
Externo à Instituição - ARTHUR GERMANO FETT NETO - UFRGS
Externo à Instituição - JOAO HENRIQUE GHILARDI LAGO - UFABC