Dieugenol: otimização da atividade biológica via oxidação anódica e complexação com lantanídeos
Data
2019
Autores
Silva, Flávia Tavares da 
Orientadores
Camilo, Fernanda Ferraz
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O dieugenol é uma neolignana encontrada em algumas plantas como, por
exemplo, na Nectandra leucanta. Seu monômero natural, o eugenol e seus derivados,
possuem uma vasta gama de aplicações, tendo propriedades antioxidantes,
antimutagênicas, antigenotóxicas, anti-inflamatórias e anticâncer já estabelecidas.
Embora exista uma vasta gama de informações sobre as atividades benéficas a saúde
humana reportada para o eugenol, trabalhos que reportem a ação do dieugenol são
escassos. Assim, este trabalho possui como objetivo principal a preparação de
derivados de dieugenol por meio de duas metodologias distintas: (a) sua complexação
com três elementos da série dos lantanídeos (cério, lantânio e európio) e (b) sua
oxidação anódica. A modificação do dieugenol pelos dois métodos propostos ainda não
foi reportada na literatura. Os complexos foram preparados usando dieugenol como
ligante e nitratos de lantanídeos hidratados como precursores metálicos. Os complexos
formados contêm os lantanídeos complexados de forma bidentada por 2 moléculas de
dieugenol, ligadas através dos oxigênios fenólicos. Essas estruturas também
apresentam um ânion nitrato, também coordenado de forma bidentada, uma molécula
de metanol e duas águas. Considerando que os 2 dieugenóis complexados e o nitrato
possuem carga (-1) e o lantanídeo (+3), os complexos têm carga neutra. Na avaliação
da citotoxicidade, para as células saudáveis de fibroblasto humano (T75), todos os
complexos se mostraram menos tóxicos que o dieugenol sendo estes dados bastante
promissores. A oxidação anódica do dieugenol realizada a 1,3 V vs Ag/AgCl gerou um
produto que tem apenas uma unidade aromática oxidada com o acréscimo de uma
metoxila em posição em orto com relação a C=O formada.
Dieugenol is a neolignan found in some plants, such as, in Nectandra leucanta. Its natural monomer, eugenol and its derivatives, have a wide range of applications, and its antioxidant, antimutagenic, antigenotoxic, anti-inflammatory and anticancer properties already established. Although there is a lot of information about the beneficial human health activities for eugenol, studies reporting the dieugenol action are scarce. Thus, the main goal of this dissertation was to prepare dieugenol derivatives using two different methodologies: (a) its complexation with three different lanthanides (cerium, lanthanum, and europium) and (b) its anodic oxidation. The modification of dieugenol by these two proposed methods has not yet been reported in the literature. The complexes were prepared using dieugenol as ligand and hydrated lanthanide nitrates as precursors. All complexes have the lanthanides complexed by two dieugenol acting as bidentate ligands, one nitrate, also bidentate by two O-atoms, one methanol, and two water molecules. Considering that each of the two complexed dieugenol and nitrate have one negative charge (-1) and the lanthanide has a charge (+3), the complexes have a neutral charge. In the cytotoxicity tests, using the healthy human fibroblast cells (T75), all complexes were less toxic than dieugenol and these data are quite promising. Anodic oxidation of dieugenol performed at 1.3 V vs Ag / AgCl generated a product with only one oxidized aromatic unity with the addition of a methoxyl in ortho position in relation to the formed C=O.
Dieugenol is a neolignan found in some plants, such as, in Nectandra leucanta. Its natural monomer, eugenol and its derivatives, have a wide range of applications, and its antioxidant, antimutagenic, antigenotoxic, anti-inflammatory and anticancer properties already established. Although there is a lot of information about the beneficial human health activities for eugenol, studies reporting the dieugenol action are scarce. Thus, the main goal of this dissertation was to prepare dieugenol derivatives using two different methodologies: (a) its complexation with three different lanthanides (cerium, lanthanum, and europium) and (b) its anodic oxidation. The modification of dieugenol by these two proposed methods has not yet been reported in the literature. The complexes were prepared using dieugenol as ligand and hydrated lanthanide nitrates as precursors. All complexes have the lanthanides complexed by two dieugenol acting as bidentate ligands, one nitrate, also bidentate by two O-atoms, one methanol, and two water molecules. Considering that each of the two complexed dieugenol and nitrate have one negative charge (-1) and the lanthanide has a charge (+3), the complexes have a neutral charge. In the cytotoxicity tests, using the healthy human fibroblast cells (T75), all complexes were less toxic than dieugenol and these data are quite promising. Anodic oxidation of dieugenol performed at 1.3 V vs Ag / AgCl generated a product with only one oxidized aromatic unity with the addition of a methoxyl in ortho position in relation to the formed C=O.