Oxido nítrico (NO) é uma molécula que participa de várias atividades fisiológicas no organismo, entre as quais incluem-se ação vasodilatadora e antitumoral. Entretanto sua resposta biológica é dependente da concentração, que quando alta apresenta citotoxicidade. Um fator limitante para sua aplicação em sistemas biológicos é seu curto tempo de meia vida no organismo, o que direcionou os estudos de complexos de rutênio-nitrosilo (RuNO) como doadores de NO. Complexos RuNO apresentam interesse especial devido suas propriedades termoestáveis e fotoquímicas. O uso da luz como um estímulo externo torna-se vantajoso pela capacidade de controlar-se a localização, o tempo de liberação da droga e a dosagem. A terapia fotodinâmica (TFD) tem sido aplicada na terapia clínica contra o câncer. TFD depende da concentração de oxigênio para a produção de espécies reativas, o que é limitado em alguns tipos de tumores devido a hipóxia. Os Pontos quânticos (PQs), semicondutor nanocristalino, destacam-se como materais funcionais com propriedade ópticas únicas dependentes do tamanho. Podem atuar como antenas na captação de luz e fotossensibilização de complexos rutênio-nitrosilo para a liberação de moléculas bioativas. Neste trabalho descrevemos a síntese e caracterização de diferentes PQs (CdS, CdSe e CdTe) utilizando diferentes agentes passivantes (ATG, TOPO e AMP)e a síntese e caracterização do complexo rutênio-nitrosilo cis-[Ru(NO)(4-amp)(bpy)2]3+ (4-amp= 4-aminopiridina; bpy = 2,2 \'bipiridina. Estudos das propriedades fotofísicas e avaliação fotoquímica da interação entre PQ e RuNO foram realizados como também a avaliação da atividade citotóxica x desta associação sobre cultura de células de melanoma murino B16-F10. As medidas das propriedades fotofísicas demonstraram interação pela supressão da fluorescência analisada pela equação de Stern-Volmer. Pela determinação do número de sítios de ligação (≈ 2) e a constante de ligação (kb) verificou-se que a interação entre as espécies apresentaram supressão da emissão em um gráfico não linear de Stern-Volmer resultante do processo de agregação entre os compostos. Os dados obtidos corroboram para o mecanismo proposto, demonstrando que cada PQ540 interage com duas moléculas de RuNO. Ainda observou-se que, sob irradiação na região do visível, em 532 nm, aumenta-se o número de mols de NO liberado de no mínimo 6 vezes quando irradiado na presença de PQs comparado à irradiação do complexo sozinho em solução. O processo de transferência eletrônica fotoinduzida foi proposto como o mecanismo fotoquímico para a liberação de NO, enquanto que o processo de transferência de energia mostrou-se desfavorável devido a não sobreposição entre os espectros de absorção do complexo nitrosilo e o espectro de emissão do PQ. As análises de imagem fluorescentes demonstraram o potencial dos PQs como marcadores celulares. As concentrações utilizadas nos experimentos não demonstraram toxicidade sobre as células de melanoma murino na ausência de luz. Porém quando irradiadas, apresentaram citotoxicidade parcial. Portanto, essa transferência pode ocorrer pela redução do NO+ para NO0, seguida pela liberação de NO ou por fotoaquação e consequente fotoredução do nitrito em solução. / Nitric oxide (NO) is a molecule involved in many physiological activities in human body among them include vasodilator and antitumoral. However, the biological response is concentration dependent and in high concentrations it causes cytotoxicity. A limiting factor for biological applications is the short half-life of NO in the body which has led to the research of nitrosyl ruthenium complexes (RuNO) as NO donors. RuNO complexes are of special interest because of their thermal stability and photochemical properties. The use of light as an external stimulus is advantageous as we can track the location, timing of drug release and dosage. Photodynamic therapy (PDT) has been used in clinical therapy for cancer treatment. PDT depends on oxygen concentrations for reactive oxygen species production what is limited in some types of tumors because of hypoxia. The Quantum dots (QDs), semiconductor nanocrystal, as functional materials, possess unique optical size-dependent properties. QDs can act as antennas in capturing light and photosensitizing ruthenium- nitrosyl complexes for release of bioactive molecules. In this work we describe the synthesis and characterization of different PQs (CdS, CdSe and CdTe) using different passivating agents (TGA, TOPO and MPA), the synthesis and characterization of ruthenium- nitrosyl complex cis-[ Ru(NO)(4- amp)( bpy )2]3+ (4 -amp = 4 - aminopyridine; bpy = 2,2 \'bipyridine ). The photophysical properties and photochemical evaluation from the interaction between QD and RuNO were done as well the citotoxicity activity from thi association on murine melanoma cell line B16-F10 . Measurements of photophysical xii properties show interactions by the quenching of fluorescence plotted with the Stern-Volmer equation. By determining the number of binding sites (≈ 2) and the binding constants ( kb ) it was found that the interaction between the species presented an emission suppression in a nonlinear curve Stern- Volmer plot resulted by the aggregation process between both compounds. The data corroborates the proposed mechanism that QD540 interacts with two molecules of RuNO. It was also observed that under irradiation in the visible region, 532 nm, that moles of NO released increases at least 6 times when irradiated in the presence of QDs compared to the irradiation of the RuNO complex alone in solution. The process of photo induced electron transfer was proposed as the mechanism for photochemical release of NO while the process of energy transfer was deemed unfavorable due to no overlap between nitrosyl complex absorption and the QD emission spectrum. The fluorescence image analysis demonstrated the potential of QDs as cell markers. The concentrations used in the experiments have not shown toxicity on murine melanoma cells in the absence of light. However when irradiated, QDs exhibited partial cytotoxicity. Therefore, this transfer may occur by the reduction of NO+ to NO0, followed by the release of NO or photoaquation and subsequent photoreduction of nitrite in solution.

Oxido nítrico (NO) é uma molécula que participa de várias atividades fisiológicas no organismo, entre as quais incluem-se ação vasodilatadora e antitumoral. Entretanto sua resposta biológica é dependente da concentração, que quando alta apresenta citotoxicidade. Um fator limitante para sua aplicação em sistemas biológicos é seu curto tempo de meia vida no organismo, o que direcionou os estudos de complexos de rutênio-nitrosilo (RuNO) como doadores de NO. Complexos RuNO apresentam interesse especial devido suas propriedades termoestáveis e fotoquímicas. O uso da luz como um estímulo externo torna-se vantajoso pela capacidade de controlar-se a localização, o tempo de liberação da droga e a dosagem. A terapia fotodinâmica (TFD) tem sido aplicada na terapia clínica contra o câncer. TFD depende da concentração de oxigênio para a produção de espécies reativas, o que é limitado em alguns tipos de tumores devido a hipóxia. Os Pontos quânticos (PQs), semicondutor nanocristalino, destacam-se como materais funcionais com propriedade ópticas únicas dependentes do tamanho. Podem atuar como antenas na captação de luz e fotossensibilização de complexos rutênio-nitrosilo para a liberação de moléculas bioativas. Neste trabalho descrevemos a síntese e caracterização de diferentes PQs (CdS, CdSe e CdTe) utilizando diferentes agentes passivantes (ATG, TOPO e AMP)e a síntese e caracterização do complexo rutênio-nitrosilo cis-[Ru(NO)(4-amp)(bpy)2]3+ (4-amp= 4-aminopiridina; bpy = 2,2 \'bipiridina. Estudos das propriedades fotofísicas e avaliação fotoquímica da interação entre PQ e RuNO foram realizados como também a avaliação da atividade citotóxica x desta associação sobre cultura de células de melanoma murino B16-F10. As medidas das propriedades fotofísicas demonstraram interação pela supressão da fluorescência analisada pela equação de Stern-Volmer. Pela determinação do número de sítios de ligação (≈ 2) e a constante de ligação (kb) verificou-se que a interação entre as espécies apresentaram supressão da emissão em um gráfico não linear de Stern-Volmer resultante do processo de agregação entre os compostos. Os dados obtidos corroboram para o mecanismo proposto, demonstrando que cada PQ540 interage com duas moléculas de RuNO. Ainda observou-se que, sob irradiação na região do visível, em 532 nm, aumenta-se o número de mols de NO liberado de no mínimo 6 vezes quando irradiado na presença de PQs comparado à irradiação do complexo sozinho em solução. O processo de transferência eletrônica fotoinduzida foi proposto como o mecanismo fotoquímico para a liberação de NO, enquanto que o processo de transferência de energia mostrou-se desfavorável devido a não sobreposição entre os espectros de absorção do complexo nitrosilo e o espectro de emissão do PQ. As análises de imagem fluorescentes demonstraram o potencial dos PQs como marcadores celulares. As concentrações utilizadas nos experimentos não demonstraram toxicidade sobre as células de melanoma murino na ausência de luz. Porém quando irradiadas, apresentaram citotoxicidade parcial. Portanto, essa transferência pode ocorrer pela redução do NO+ para NO0, seguida pela liberação de NO ou por fotoaquação e consequente fotoredução do nitrito em solução. / Nitric oxide (NO) is a molecule involved in many physiological activities in human body among them include vasodilator and antitumoral. However, the biological response is concentration dependent and in high concentrations it causes cytotoxicity. A limiting factor for biological applications is the short half-life of NO in the body which has led to the research of nitrosyl ruthenium complexes (RuNO) as NO donors. RuNO complexes are of special interest because of their thermal stability and photochemical properties. The use of light as an external stimulus is advantageous as we can track the location, timing of drug release and dosage. Photodynamic therapy (PDT) has been used in clinical therapy for cancer treatment. PDT depends on oxygen concentrations for reactive oxygen species production what is limited in some types of tumors because of hypoxia. The Quantum dots (QDs), semiconductor nanocrystal, as functional materials, possess unique optical size-dependent properties. QDs can act as antennas in capturing light and photosensitizing ruthenium- nitrosyl complexes for release of bioactive molecules. In this work we describe the synthesis and characterization of different PQs (CdS, CdSe and CdTe) using different passivating agents (TGA, TOPO and MPA), the synthesis and characterization of ruthenium- nitrosyl complex cis-[ Ru(NO)(4- amp)( bpy )2]3+ (4 -amp = 4 - aminopyridine; bpy = 2,2 \'bipyridine ). The photophysical properties and photochemical evaluation from the interaction between QD and RuNO were done as well the citotoxicity activity from thi association on murine melanoma cell line B16-F10 . Measurements of photophysical xii properties show interactions by the quenching of fluorescence plotted with the Stern-Volmer equation. By determining the number of binding sites (≈ 2) and the binding constants ( kb ) it was found that the interaction between the species presented an emission suppression in a nonlinear curve Stern- Volmer plot resulted by the aggregation process between both compounds. The data corroborates the proposed mechanism that QD540 interacts with two molecules of RuNO. It was also observed that under irradiation in the visible region, 532 nm, that moles of NO released increases at least 6 times when irradiated in the presence of QDs compared to the irradiation of the RuNO complex alone in solution. The process of photo induced electron transfer was proposed as the mechanism for photochemical release of NO while the process of energy transfer was deemed unfavorable due to no overlap between nitrosyl complex absorption and the QD emission spectrum. The fluorescence image analysis demonstrated the potential of QDs as cell markers. The concentrations used in the experiments have not shown toxicity on murine melanoma cells in the absence of light. However when irradiated, QDs exhibited partial cytotoxicity. Therefore, this transfer may occur by the reduction of NO+ to NO0, followed by the release of NO or photoaquation and subsequent photoreduction of nitrite in solution.

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Salvador, BA, Brasil / A candidíase é uma infecção oportunista provocada por diversas espécies de fungos do gênero Candida, frequentemente encontrados integrando a microbiota, da superfície cutânea, no trato gastrointestinal e cavidades mucosas do ser humano desde o seu nascimento. A incidência das infecções fúngicas sistêmicas têm aumentado consideravelmente nas últimas décadas em função do grande número de pacientes com SIDA, a grande quantidade de transplantes e condições crônicas como o câncer, a terapia prolongada com imunossupressores e o uso de agentes corticosteroides. Além disso, a exposição prolongada aos antifúngicos azólicos promove a seleção de patógenos resistentes. No presente estudo avaliou-se a atividade antifúngica do complexo Rutênio-pirocatecol (RPC) frente a um isolado clinico de Candida tropicalis resistente ao fluconazol. A metodologia empregada para os testes de susceptibilidade foi de acordo com o documento M27-A3 do National Committee for Clinical Laboratory Standards (NCCLS, 2008). Esplenócitos de camundongos Balb/c foram obtidos de forma asséptica para avaliar a citotoxicidade do composto para células de mamíferos. O estresse oxidativo promovido pelo composto foi avaliado através da reação ao ácido tiobarbitúrico (TBARS) e ensaios de fluorescência com a sonda diclorodihidrofluoresceína diacetato (DCFH2DA). O Calcofluor White foi empregado para avaliar a integridade da parede celular. A análise ultraestrutural foi realizada através da microscopia eletrônica de varredura e transmissão. Os resultados encontrados para os testes de atividade antifúngica foram analisados através do teste estatístico ANOVA e pós-teste Dunnett. Os resultados encontrados para os testes de atividade antifúngica do RPC mostraram uma Concentração Inibitória de 50% (IC50) de 20,3 μM, enquanto em esplesnócitos a concentração efetiva de 50% foi de 325 μM mostrando um índice de seletividade igual a 16. O referido composto também mostrou um elevado efeito pró-oxidante quando avaliamos os níveis de estresse oxidativo através da TBARS e por meio da sonda DCFH2DA. Quando as leveduras foram tratadas por 24 h com o referido composto, observamos na microscopia de varredura o desenvolvimento de pseudo-hifas com 9 μM, a formação de fissuras em sua parede e uma forte agregação das células com 18 μM, além disso, encontramos uma intensa redução na quantidade de células e muito debris celular com 38 μM. Na microscopia de transmissão observamos estruturas vesiculares no espaço periplasmático associado a grânulos eletrondensos, os quais também foram vistos associados a parede celular, quando tratadas por 3h com 40 μM. No tratamento por 24h com 60 μM observamos a referida estrutura granular eletrondensa no citoplasma envolta por membrana, uma grande quantidade destas estruturas no espaço citoplasmático e associado a parede da célula, além disso, também observamos trechos de membrana associado a estas estruturas no espaço extracelular. Em conclusão, a atividade antifúngica e o índice de seletividade do RPC contra uma cepa resistente é consideravelmente interessante devido as suas possibilidades de aplicações na descoberta de novos antifúngicos / Candidiasis is an opportunistic infection caused by several species of fungi of the genus Candida, often found is the microbiota, on the skin, gastrointestinal tract and mucous cavities of the human beings birth. The incidence of systemic fungal infections have increased considerably in recent decades due to the large number of AIDS patients, the large number of transplants and chronic conditions such as cancer, prolonged therapy promotes the selection of resistant pathogen with immunosuppressant and corticosteroid agents. Also prolonged exposure azole antifungals to make them strong candidates for patients resistance. In the present study we evaluated the antifungal activity of Ruthenium-pyrocatechol complex (RPC) against a clinical isolate of Candida tropicalis resistant to fluconazole. The methodology for susceptibility testing was in accordance with the M27-A3 document of there National Committee for Clinical Laboratory Standards (NCCLS, 2008). Splenocytes from Balb/c mice were obtained aseptically to evaluate the cytotoxicity of the compound to mammalian cells. Oxidative stress caused by the compound was assessed by reaction to thiobarbituric acid (TBARS) and fluorescence assays with the probe diclorodihidrofluoresceína diacetate (DCFH2DA). The Calcofluor White was used to evaluate the integrity of the cell wall. The ultrastructural analysis was performed by scanning and transmission electron microscopy. The results for the antifungal activity tests were analyzed using ANOVA and pos-test Dunnett test statistic. The results for the tests of antifungal activity of the RPC showed a 50% inhibitory concentration (IC50) of 20.3 μM while in splenocytes the 50% effective concentration was 325 μM showing a selectivity index of 16. The compound also showed that a high pro-oxidant effect when evaluated levels of oxidative stress by TBARS and through DCFH2DA staining. When yeast cells were treated for 24 h with this probe, in scanning microscopy we observed the development of pseudohyphae 9 μM, the formation of cracks on their fungal walls and in these cell aggregation with 18 μM furthermore found a remarkable reduction in the number of cells, and cell debris with 38 μM. In transmission microscopy vesicular structures observed in the periplasmic space associated with electrondense granules, which were also seen associated with the cell wall, when there cells were treated for 3 h with 40 μM. In the treatment for 24h with 60 μM observed that the grain structure in the clusters in periplasmic, a large amount of these structures in the cytoplasmic space and associated with the cell wall, moreover, we also observe membrane portions associated with these structures in the extracellular space. In conclusion, the antifungal activity and the selectivity index RPC against a resistant strain is pretty interesting because of its possible applications in the discovery of new antifungal agents.

L’objectif de cette thèse est de préparer et caractériser de nouveaux agents théranostiques potentiels à base de complexes de ruthénium portant des molécules biologiquement actives. Pour évaluer potentiel théranostique des nouveaux composés les propriétés de luminescence et la cytotoxicité ont été considérées. Quatre nouveaux ligands portant des substituants a activité biologique: 5-(4-4’-methyl-[2,2’-bipyridine]-4-ylbut-1-yn-1-yl)pyridine-2-carbaldehyde semicarbazone (L1), 3-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)imidazolidine-2,4-dione (L2), 5,5-dimethyl-3-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)imidazolidine-2,4-dione (L3) and [1-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)-2,5-dioxoimidazolidin-4-yl]urea (L4) ont été prepares, caractérisés et engagés dans la synthese des complexes de ruthénium correspondants. Six complexes ont été obtenus a partir du ligand L1 ([Ru(bpy)2(L1)]2+, [Ru(Mebpy)2(L1)]2+, [Ru(tBubpy)2(L1)]2+, [Ru(Phbpy)2(L1)]2+, [Ru(dip)2(L1)]2+, [Ru(SO3dip)2(L1)]2-) et trios a partir de L2, L3 and L4 ([Ru(bpy)2(L2)]2+, [Ru(bpy)2(L3)]2+, [Ru(bpy)2(L4)]2+) (bpy = 2,2’-bipyridine, Mebpy = 4,4’-dimethyl-2,2-bipyridine, tBubpy = 4,4’-tert-butyl-2,2’-bipyridine, Phbpy = 4,4’-diphenyl-2,2-bipyridine, dip = 4,7-diphenyl-1,10-phenantroline and SO3dip = 4,7-di-(4-sulfonatophenyl)-1,10-phenantroline). Les propriétés spectroscopiques et photophysiques des composés ont été étudiées. La présence des ligands L1-L4 conduit a une décroissance du rendement quantique et de la durée de vie de l’état excité en comparaison des complexes non substitués [Ru(bpy)3]2+. Des calculs DFT montrent que les ligands L1-L4 n’influencent pas la géométrie du complexe mais accroissent le niveau énergétique de la HOMO induisant des band gap HOMO-LUMO plus faibles. Les interactions entre les complexes et l’human serum albumin (HSA) ont été étudiées. Tous les complexes préparaés montrent une tres forte affinité pour HSA – La constante d’association 105 M-1s-1 témoigne de la formation d’adduits Ru-HSA stables. Il a aussi été démontré que les complexes de ruthénium se lient préférentiellement a la poche hydrophobe des protéine, située dans le site 1 de Sudlow dans le sous domaine II A. Des études préliminaires ont montré que les complexes de ruthénium préparés presentent une activité cytotoxique vis-à-vis de diverses lignées de cellules cancéreuses. Cette activité associée aux bonnes propriétés de luminescence (rendement quantique, durée de vie) fait des nouveaux complexes des candidats potentiels pour les applications théranostiques / The main goal of this thesis was synthesis and preliminary characterization of novel ruthenium(II) polypyridyl complexes bearing biologically active molecules as potential theranostic agents. Luminescence for the diagnostic applications, and cytotoxicity for the anticancer, therapeutic applications are considered as the theranostic properties. Four new ligands containing biologically active moieties - 5-(4-4’-methyl-[2,2’-bipyridine]-4-ylbut-1-yn-1-yl)pyridine-2-carbaldehyde semicarbazone (L1), 3-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)imidazolidine-2,4-dione (L2), 5,5-dimethyl-3-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)imidazolidine-2,4-dione (L3) and [1-(5-4’-methyl-[2,2’-bipyridine]-4-ylpentyl)-2,5-dioxoimidazolidin-4-yl]urea (L4) were synthesized and characterized. The ligands were used to obtain nine novel ruthenium(II) polypyridyl complexes. Six complexes were synthesized with ligand L1 ([Ru(bpy)2(L1)]2+, [Ru(Mebpy)2(L1)]2+, [Ru(tBubpy)2(L1)]2+, [Ru(Phbpy)2(L1)]2+, [Ru(dip)2(L1)]2+, [Ru(SO3dip)2(L1)]2-) and three with ligands L2, L3 and L4 ([Ru(bpy)2(L2)]2+, [Ru(bpy)2(L3)]2+, [Ru(bpy)2(L4)]2+) (bpy = 2,2’-bipyridine, Mebpy = 4,4’-dimethyl-2,2-bipyridine, tBubpy = 4,4’-tert-butyl-2,2’-bipyridine, Phbpy = 4,4’-diphenyl-2,2-bipyridine, dip = 4,7-diphenyl-1,10-phenantroline and SO3dip = 4,7-di-(4-sulfonatophenyl)-1,10-phenantroline). The spectroscopic and photophysical properties of those complexes were determined. The presence of ligands L1-L4 in the structure of the complex decreased luminescence quantum yield and luminescence lifetime in comparison with unmodified [Ru(bpy)3]2+ complex. The theoretical calculations have shown that ligands L1-L4 do not have influence on ruthenium core geometry. However, they increased the energy of the HOMO that resulted in a shorter band gap. The simulated electronic absorption spectra were in a good agreement with the experimental data. The interactions between the studied ruthenium complexes and human serum albumin (HSA) were investigated. All studied Ru(II) complexes exhibited strong affinity to HSA with the association constant 105 M-1s-1, which suggests formation of Ru complex-HSA adducts. It was also determined that ruthenium complexes most likely bind to the hydrophobic pocket of protein, located in Sudlow’s site I in the subdomain II A. Preliminary cytotoxicity evaluation for the studied ruthenium complexes showed their cytotoxic activity towards cancer cell lines. Those results, together with good luminescence properties of the studied ruthenium complexes (luminescence lifetimes and luminescence quantum yield) make them interesting candidates for potential theranostic applications

Two series of new mononuclear ruthenium complexes with hydrophobic or hydrophilic ligands [Ru(bda)L2] and [Ru(pdc)L3] (H2bda = 2,2'-bipyridine-6,6'-dicarboxylic acid; H2pdc = 2,6-pyridinedicarboxylic acid; L = pyridyl ligands) were synthesized and their electrochemical properties and catalytic activity toward water oxidation were examined. It was revealed that the hydrophobic ligands introduced to [Ru(bda)L2 ] improved the catalytic performance, ahnost twofold TON and TOF values were achieved compared to the [Ru(bda)] catalyst with hydrophilic ligands. The cyclic voltammogram of [Ru(bda)L2] exhibited marginal difference between the catalysts with hydrophobic ligands and hydrophilic ones, implying that the hydrophobic ligands promoted the catalytic activity by :lacilitating formation of a reaction intermediate dimer.

O óxido nítrico (NO) é biossintetizado em diferentes células do organismo animal, relacionando-se com inúmeros processos fisiológicos. Existe, aparentemente, uma relação entre os efeitos mediados pelo NO e o microambiente celular. Desta forma, a resposta observada depende da localização da molécula radicalar, da duração da exposição e da sua concentração. Assim, observa-se um efeito antagônico do NO no que tange a biologia de tumores, admitindo-se que baixas concentrações de NO estimulam a proliferação de células tumorais e altas concentrações propiciam a atividade tumoricida. Nesse sentido, o presente trabalho visou ao desenvolvimento de um novo complexo de rutênio doador de óxido nítrico coordenado ao ligante fluorescente Alaranjado de Acridina. A coordenação do rutênio ao ligante heterocíclico de nitrogênio permitiu a obtenção do composto fluorescente [Ru(NO2)(bpy)(AO)2NO](PF6)2, em que bpy = 2,2\'bipiridina e AO = Alaranjado de Acridina. O complexo foi caracterizado por UV-vis, FITR e espectrometria de massas. Experimentos fotoquímicos revelaram que o complexo [Ru(NO2)(bpy)(AO)2NO](PF6)2 apresentou um valor de rendimento quântico de fluorescência em etanol inferior ao do ligante livre. No entanto, o rendimento quântico de produção de oxigênio singleto em água foi maior em relação ao Alaranjado de Acridina. Avaliações de fotoestabilidade por espectroscopia de emissão e absorção no UV-vis demonstraram que [Ru(NO2)(bpy)(AO)2NO](PF6)2 é mais fotoestável nas condições avaliadas e a fluorescência apresenta menor redução, quando irradiado em 470 nm comparado ao Alaranjado de Acridina. Ensaios de avaliação do potencial citotóxico dos compostos com irradiação em 470 nm, na dose de 5 J cm-², demonstraram que o corante Alaranjado de Acridina apresenta maior citotoxicidade frente à linhagem celular tumoral metastática estudada (B16/F10). Isso se relaciona, possivelmente, ao fato de o Alaranjado de Acridina livre direcionar-se para o núcleo e promover intercalação com os pares de base do DNA. A avaliação por microscopia de fluorescência revelou a predileção do complexo [Ru(NO2)(bpy)(AO)2NO](PF6) pelo núcleo. Os dados obtidos enfatizam a importância do grupo ligante para a localização do complexo, bem como para a atividade antitumoral do mesmo. / Nitric Oxide is biosynthesized in different cells of the animal organism. It is related to numerous physiological processes. There is apparently a relationship between the effects mediated by NO and the microenvironment. Thus, the cellular response observed depends on the location of the radical molecule, the duration of exposure and its concentration. Thus, an antagonistic effect of NO is observed with respect to the biology of tumors, admitting that low concentrations of NO stimulate the proliferation of tumor cells and high concentrations promote the tumoricidal activity. In this sense, the present work aimed the development of a new ruthenium complex donor of nitric oxide coordinated to the fluorescent ligand of Acridine. The coordination of Ruthenium to the nitrogen heterocyclic ligand allowed to obtain the fluorescent compound [Ru(NO2)(bpy)(AO)2NO](PF6)2, where bpy = 2,2\' bipyridine and AO = Acridine Orange, which was characterized by UV-Vis, FITR and mass spectrometry. Photochemical experiments revealed that the [Ru(NO2)(bpy) (AO)2NO](PF6) 2 complex presented a fluorescence quantum yield value, in ethanol, about 20 % lower than the free binder. However, the quantum yield of singlet oxygen in water was approximately 40 % higher compared to Acridine Orange. UV-vis emission spectroscopy and UV-vis absorption spectroscopy have shown that [Ru (NO2)(bpy)(AO)2NO](PF6) 2 is apparently more photostable and suffers less fluorescence suppression when irradiated at 470 nm compared with Acridine Orange. Cell cytotoxicity assays with irradiation using dose of 5 J cm-2 demonstrated that the coordination of Acridine Orange dye to the complex decreases its cytotoxicity against the metastatic tumor cell line studied, possibly by preventing the mechanism of intercalation of the planar ligand to DNA. Monitoring by fluorescence microscopy revealed the preferential localization of the compound [Ru(NO2)(bpy) (AO)2NO] (PF6) by the cell nucleus possibly due to coordinated Acridine Orange, which has a tropism by DNA. These results emphasize the importance of the ligand group for the localization of the complex, as well as for the cytotoxic activity of the same

Made available in DSpace on 2017-07-20T12:40:14Z (GMT). No. of bitstreams: 1 Bianca Sandrino.pdf: 3429333 bytes, checksum: e320b1605b6c2c81bf2ecd35d8aa88f5 (MD5) Previous issue date: 2014-09-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / One of the major challenges in drug design is to identify compounds with potential toxicity toward target cells, preferably with molecular-level understanding of their mode of action. In this study, the antitumor property of a ruthenium complex, mer-RuCl3(dppb)(VPy)] (dppb = 1,4-bis (diphenylphosphine) butane and VPy = 4-vinylpyridine),RuVPy) was analyzed. Results showed that this compound led to a mortality rate of 50% of human laryngeal carcinoma HEp-2 cell with 120 ±10 mol L-1, indicating its high toxicity. Toward a better understanding if its mode of action is associated with its interaction with cell membranes, Langmuir monolayers were used as a membrane model. RuVPy had a strong effect on the surface pressure isotherms, especially on the elastic properties of the zwitterionic dipalmitoylphosphatidylcholine (DPPC) and the negatively charged dipalmitoylphosphatidylglycerol (DPPG) and dipalmitoylphosphatidylserine (DPPS) phospholipids. Results of thermodynamic parameters indicated miscibility between the components is not ideal mixed monolayers. Preferably attractive and repulsive interactions between RuVPy and zwitterionic or anionic phospholipids, respectively, are observed with mixed monolayer of DPPS/RuVPy energetically unfavorable. These data were confirmed polarization - modulated infrared reflection-absorption spectroscopy (PM-IRRAS). In addition, interactions between the positive group from RuVPy and the phosphate group from phospholipids were corroborated by density functional theory (DFT) calculations, allowing the determination of the Ru complex orientation at the air-water interface. Proof of interaction was confirmed by electrochemical results of Langmuir-Blodgett films of the phospholipid/RuVPy mixture. The presence of the RuVPy on the conductor substrate, which presents higher electron density, form "defects" in the monolayer of phospholipids increasing accumulation of electrons in the electrode/solution interface making it more permeable material. Although possible contributions from receptors or other cell components cannot be discarded, the results reported here represent evidence for significant effects on the cell membranes which are probably associated with the high toxicity of RuVPy. / Um dos grandes desafios na concepção de medicamentos é a identificação de compostos com potencial toxicidade para as células-alvo e a compreensão do seu modo de ação. Nesta tese, foi analisada a propriedade antitumoral do complexo de rutênio mer-[RuCl3(dppb)(VPy)] (dppb = 1,4-bis (difenilfosfina)butano e VPy = 4-vinilpiridina) (RuVPy), e os resultados mostraram que este composto levou a uma taxa de mortalidade de 50% de células de câncer de laringe (HEp-2) com 120 ± 10 μmol L-1, indicando sua alta toxicidade. Para a compreensão do modo de ação em nível molecular deste complexo, associada à sua interação com membranas celulares, monocamadas de Langmuir foram utilizadas como um modelo simples de membrana. O RuVPy apresentou um forte efeito sobre as isotermas de pressão de superfície, especialmente sobre as propriedades elásticas do zwitteriônico dipalmitoilfosfatidilcolina (DPPC) e dos fosfolipídios carregados negativamente dipalmitoilfosfatidilglicerol (DPPG) e dipalmitoilfosfatidilserina (DPPS). Resultados dos parâmetros termodinâmicos indicaram que há miscibilidade entre os componentes das monocamadas mistas não ideais. Interações preferencialmente atrativas e repulsivas foram constatadas entre o RuVPy e os fosfolipídios zwitteriônico e aniônicos, respectivamente, sendo a monocamada mista de DPPS/RuVPy energeticamente desfavorável. A interação entre o grupo de maior densidade eletrônica do RuVPy, obtido por cálculo de teoria funcional da densidade (DFT), e o grupo fosfato dos fosfolipídios foi confirmada por espectroscopia de infravermelho de reflexão e absorção de modulo polarizado (PM-IRRAS) realizada na interface ar-água. Prova desta interação foi constatada por resultados eletroquímicos dos filmes Langmuir-Blodgett da mistura fosfolipídio/RuVPy. A presença do complexo no substrato condutor, por ter maior densidade eletrônica, forma “defeitos” na monocamada dos fosfolipídios aumentando o acúmulo de elétrons na interface eletrodo/solução tornando o material mais permeável. Desta forma, é evidente que além de eventuais contribuições de outros receptores ou componentes celulares não poderem ser descartadas, os resultados aqui apresentados trazem os efeitos significativos nas membranas celulares que provavelmente estão associados à alta toxicidade do RuVPy.

Tout au long de cette thèse, de nouveaux colorants organométalliques ont été élaborés dont le but est de les utiliser en tant que photosensibilisateurs au sein des cellules solaires DSSC dont la simplicité de mise en œuvre, le faible coût de production et un design attractif en sont les atouts majeurs. Des analogues du black dye ont dans un premier temps été élaborés, une étude approfondie par des calculs DFT a permis une approche plus constructive sur le choix des designs moléculaires. Des aldéhydes dérivés de la biomasse comme la vanilline, le syringaldéhyde ou le 5-hydroxyméthylfurfural ont permis de substitués le ligand terpyridine par différents groupes (hétéro)aromatiques en position 4’ pour moduler les transferts de charges. Dans un second temps, une chaîne hexyloxyméthyle est introduite en position 4’’ pour diminuer les recombinaisons de charges lors du fonctionnement de la cellule solaire et par la même occasion placer la LUMO plus proche des points d’ancrages pour de meilleures injections de charges vers le semi-conducteur. L’utilisation de groupes cyanoacrylates a aussi été envisagé à la place des acides carboxyliques afin d’obtenir des absorptions plus panchromatiques. Des complexes du type [Ru(tpy)2] et [Ru(tpy)(bpy)NCS] ont également été synthétisés et étudiés pour leur stabilités plus accrues au cours du temps au sein de la cellule solaire par rapport aux complexes à ligands NCS. Certains colorants ont été testés en cellules solaires en combinaison du dioxyde de titane comme semi-conducteur et du couple I3-/I- en tant que médiateur rédox. / Throughout this thesis, new organometallic dyes have been developed to use them as photosensitizers in dye-sensitized solar cells (DSSCs), whose simplicity of implementation, low cost production and attractive design are major assets. Black dye analogues were first developed, a thorough study of DFT calculations allowed a more constructive approach to the choice of molecular designs. Biomass-derived aldehydes such as vanillin, syringaldehyde or 5-hydroxymethylfurfural have been used to substitute the terpyridine ligand by different (hetero)aromatic groups in the 4’ position in order to modulate charge transfers. In a second step, a hexyloxymethyl chain was introduced in the 4'' position with the aim of reduce charge recombination during the solar cell operation and in the same time to place the LUMO closer to the anchoring groups for better charge injections to the semiconductor. The use of cyanoacrylate groups was also considered in place of the carboxylic acids in order to obtain more panchromatic absorptions. [Ru(tpy)2] and [Ru(tpy)(bpy)NCS] complexes have also been synthesized and studied for their increased stability over time in the solar cell compared to the NCS ligand complexes. Some dyes have been tested in solar cells in combination of titanium dioxide as the semiconductor and the I3-/I- couple as the redox mediator.

Le monoxyde d'azote NO• est impliqué dans de nombreux processus biologiques. Il intervient, entre autres, dans la vasodilatation, la neurotransmission, il peut impliquer le développement ou l'apoptose des cellules et possède également des propriétés bactéricides. Le contrôle de la libération de ce radical est donc de grand intérêt pour des applications biomédicales en chimiothérapie photo-activée (PACT) ainsi qu'en inactivation photo-dynamique (PDI). La stratégie ici est de synthétiser des complexes de ruthénium à ligand nitrosyle photoréactifs, qui sont capables de libérer NO• sous irradiation mono ou biphotonique. L'excitation à deux photons permet une irradiation dans la fenêtre thérapeutique, très focalisée et une pénétration du faisceau plus profonde qu'en monophotonique. Ces travaux de thèse sont consacrés à la synthèse et l'étude des propriétés photochimiques de complexes [RuNO] et à leurs applications en biologie. Le premier chapitre de cette thèse développe l'état de l'art dans le domaine des complexes de ruthénium à ligand nitrosyle et présente les enjeux biologiques. Le second chapitre présente les propriétés de photolibération de NO• de complexes possédant le ligand 4'-(2-fluorényl)-2,2':6',2''-terpyridine, sous excitation à un et à deux photons par des études spectroscopiques. Les photoproduits obtenus sont caractérisés par diffraction des rayons X. Dans un troisième chapitre, l'étude des complexes cis (Cl,Cl)- et trans (Cl,Cl)-[RuII(fluorène-terpyridine)Cl2NO]PF6 est menée dans l'eau. Les capacités de photolibération du trans (NO,OH)-[RuII(fluorène-terpyridine)(Cl)(OH)(NO)]PF6 dans les conditions biologiques sont étudiées. Le quatrième chapitre s'intéresse à la synthèse de nouveaux complexes constitués de ligands dérivés du 4'-(2-fluorényl)-2,2':6',2''-terpyridine et à leurs propriétés de photolibération de NO•. Le cinquième chapitre s'intéresse aux propriétés phototoxiques de ces complexes envers des cellules cancéreuses (HCT 116 et FaDu). Enfin, dans le sixième chapitre, les propriétés remarquables de ces systèmes dans la levée de la résistance de Staphylococcus epidermidis aux antibiotiques sont exposées. / Nitric oxide NO• is involved in numerous biological processes. It takes part to vasodilatation, neurotransmission, it can trigger cell proliferation or apoptosis and it also has bactericidal properties. Thus, NO• release control is of high interest for biomedical applications such as photo-activated chemotherapy (PACT) or photodynamic inactivation (PDI). The strategy here is to synthesize photoreactive ruthenium complexes with nitrosyl ligand which can release NO• under one and two-photon absorption. Compared with one-photon excitation, two-photon excitation allows high focalization and deep penetration of the beam, while exciting in the therapeutic window. This thesis is dedicated to the synthesis of [RuNO] complexes and their biological applications. The first chapter develops the state of the art in the field of ruthenium nitrosyl complexes and presents the biological issues. The second chapter presents the NO• photorelease properties of complexes with 4'-(2-fluorenyl)-2,2':6',2''-terpyridine ligand under one and two-photon excitation by spectroscopic studies. Photoproducts are characterized by X-ray diffraction. In a third chapter, cis (Cl,Cl)- and trans (Cl,Cl)-[RuII(2-fluorene-terpyridine)Cl2NO]PF6 are studied in water. The photorelease capacities of trans (NO,OH)-[RuII(fluorene-terpyridine)(Cl)(OH)(NO)]PF6 are studied in biological conditions. The fourth chapter presents the synthesis of new complexes with 4'-(2-fluorenyl)-2,2':6',2''-terpyridine ligand derivatives and their photorelease properties. The fifth chapter describes the phototoxic studies of these complexes on cancer cells (HCT 116 and FaDu). Finally, in the sixth chapter, the outstanding properties of these systems in the falling of antibiotic resistance in Staphylococcus epidermidis are exposed.

The theme of this thesis is the development of mononuclear Ru-based complexes that are capable of catalyzing the water oxidation (or O2-evolving) reaction, e.g. 2 H2O → O2 + 4 H+ + 4 e−. Several families of mononuclear Ru water oxidation catalysts were designed and prepared. They feature with anionic ancillary ligands that contain carboxylate or phenolate donors. The properties of the catalysts were investigated in various aspects including coordination geometry, electrochemical behavior, and ligand exchange. All catalysts showed outstanding catalytic activity towards water oxidation in the presence of cerium(IV) ammonium nitrate as a sacrificial oxidant. High-valent Ru intermediates involved in the reactions were characterized both experimentally and theoretically. The kinetics of catalytic water oxidation was examined based on one catalyst and a prevailing catalytic pathway was proposed. The catalytic cycle involved a sequence of oxidation steps from RuII−OH2 to RuV=O species and O−O bond formation via water-nucleophilic-attack to the RuV=O intermediate. By comparing properties and catalytic performance of Ru catalysts herein with that of previously reported examples, the effect of anionic ancillary ligands was clearly elucidated in the context of catalytic water oxidation. Aiming to further application in an envisaged artificial photosynthesis device, visible light-driven water oxidation was conducted and achieved primarily in a homogeneous three-component system containing catalyst, photosensitizer, and sacrificial electron acceptor. Moreover, one model Ru catalyst was successfully immobilized on ordinary glass carbon surface through a facile and widely applicable method. / <p>QC 20121112</p>