masterThesis
Reações biomiméticas com metaloporfirinas de metabólitos secundários das folhas de Passiflora edulis var. flavicarpa Degener
Fecha
2018-07-31Registro en:
CHAGAS, Mariane Barreto das. Reações biomiméticas com metaloporfirinas de metabólitos secundários das folhas de Passiflora edulis var. flavicarpa Degener. 2018. 88f. Dissertação (Mestrado em Ciências Farmacêuticas) - Centro de Ciências da Saúde, Universidade Federal do Rio Grande do Norte, Natal, 2018.
Autor
Chagas, Mariane Barreto das
Resumen
Orientin and isoorientin are C-glycosidic flavonoids and markers of the species
Passiflora edulis var. flavicarpa Degener and other plant species, which are reported in the
literature for their various pharmacological properties. To evaluate and characterize the in
vitro metabolism of these flavonoids, phase I biotransformation reactions using Salen
complexes were simulated. Thus, through the techniques of classical column chromatography
and HPLC, orientin and isoorientin were isolated from the hydroethanolic extract of the
leaves P. edulis. These flavonoids were subjected to reactions with m-CPBA and PhIO as
oxidants and catalyzed by the Jacobsen catalyst (Mn (Salen)), an efficient and easily
synthesized and purified catalyst, and with the synthesized catalyst [Mn (3MeOSalen) Cl], not
reported yet in biomimetic studies, which was characterized by spectroscopic and
electrochemical techniques, highlighting its oxidation potential, higher than the potential of
the Jacobsen catalyst. By HPLC-DAD quantification, the reaction of isoorientin with mCPBA in the ratio 1:20:20 (catalyst: oxidant: flavonoid) showed higher consumption of the
substrate for both catalysts when compared to others oxidants, while the reaction of the
orientin with PhIO in the proportion 1:10:10 showed higher substrate consumption also for
both catalysts. The best condition was optimized showing that the orientin and isoorientin
isomers exhibits distinct reactivity. The reaction’s products were characterized by HPLC-MS
and HPLC-MS/MS, 3 for orientin and 5 for isoorientin, where the [Mn (3MeOSalen) Cl]
catalyst formed a larger number of compounds, and with the addition of two oxygen, whereas
the Jacobsen’s catalyst formed compounds with the addition of only one oxygen atom. The
products characterized were not found in the literature, however the formation of epoxides,
which are compounds highly reactive, is highlighted. Thus, this study can serve as a basis for
subsequent pharmacological and toxicological studies that confirm the presence of these
compounds as phase I metabolites and ensure the safety of the use of plant products that have
isoorientin and orientin as markers.