A própolis vermelha brasileira tem atraído interesses científicos e econômicos devido às suas variadas atividades biológicas. Este produto natural possui composição química diferente de acordo com a região na qual é encontrado, sendo necessária uma completa caracterização química para cada tipo de própolis, a fim de se elucidar os compostos presentes e possivelmente responsáveis por estas atividades. Dentre as atividades biológicas mais investigadas, destacam-se as atividades antioxidante e antitumoral. Neste trabalho, buscou-se caracterizar quimicamente o extrato hidroalcoólico da própolis vermelha brasileira, avaliar as atividades antioxidantes e antitumorais, além de investigar o padrão proteico de células tumorais de laringe tratadas e não tratadas com extratos da própolis vermelha através da análise proteômica comparativa. A caracterização química realizada através de espectrometria de massas com ionização por electrospray mostrou que a própolis apresenta moléculas complexas, principalmente isoflavonoides, compostos com importantes atividades biológicas. Os extratos hidroalcoólicos obtidos a partir da própolis vermelha revelaram um significante conteúdo de polifenóis associados a uma habilidade de sequestrar radicais livres DPPH·. Os extratos também apresentaram atividades superóxido-dismutase-/ike e catalase-/ike, indicando que podem exercer um papel fundamental na manutenção fisiológica do equilíbrio redox quando em um organismo. A atividade citotóxica dos extratos da própolis foi avaliada nas linhagens tumorais Hep-2, HeLa e não tumoral Hek-293, sendo que os valores de IC50 foram menores para a linhagens tumorais em relação a não tumoral. Desta forma, sugere-se uma seletividade da própolis vermelha quanto às linhagens tumorais. A análise proteômica, usando eletroforese bidimensional associada à cromatografia líquida de alta eficiência acoplada a espectrômetro de massa, permitiu a comparação dos mapas proteicos da linhagem Hep-2, na ausência ou presença de extratos da própolis vermelha, nas concentrações 6 f.1g/mL (não citotóxica) e 120 f.lg/mL (IC50). A excisão manual de 325 spots foi efetuada nos géis 2D- SDS-PAGE, em que 177 proteínas foram identificadas. Estas proteínas foram relacionadas com diversos processos metabólicos e estruturais como produção e conversão de energia, transporte e metabolismo de carboidratos, modificação pós-traducional, reciclagem de proteínas e chaperonas, proteínas do citoesqueleto, proteínas de reparo, entre outros. Das proteínas identificadas com expressão diferencial, cinco apresentaram expressão reduzida na presença do extrato da própolis, este em sua maior concentração (120 f.lg/mL). Apenas duas proteínas identificadas neste estudo mostraram expressão aumentada na concentração não citotóxica (6 f.lg/mL) do extrato da própolis vermelha. Os resultados da proteômica comparativa mostram que a própolis interfere em um conjunto de eventos intracelulares e, assim, passa a ser uma candidata promissora para inibir o crescimento celular e contribuir para os diferentes passos relacionados com o processo de carcinogênese. Embora os mecanismos moleculares pelos quais a própolis vermelha interaja com o metabolismo das células permaneçam ainda desconhecidos, estudos adicionais servirão para melhor elucidar as atividades antioxidantes e antitumorais aqui observadas. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Brazilian red propolis has attracted scientific and economic interests because of its varied biological activities. This natural product has different chemical compositions according to the region in which it is found, requiring a robust chemical characterization to elucidate the compounds responsible for the activities in each type of propolis investigated. So far antioxidant and antitumor properties are amongst the most studied biological activities. This study aimed to characterize chemically the hydroalcoholic extract of Brazilian propolis from the state of Sergipe, evaluate the antitumor and antioxidant activities, and to investigate the pattern o f proteins in tumor cells o f the larynx treated o r not with extracts of propolis through comparative proteomic analysis. The chemical characterization by mass spectrometry with electrospray ionization showed that propolis presents complex molecules, especially isoflavones, which has important biological and antioxidant capacity. The hydroalcoholic extracts obtained from propolis revealed a significant content of polyphenols associated with the ability to scavenge DPPH. radicais. The extracts also showed significant activities for superoxide dismutase-like and catalase-like, indicating an important role in maintaining physiological redox equilibrium, decreasing oxidative stress. Cytotoxic activity was assessed for tumor cell !ines Hep-2, HeLa and non-tumor cell line Hek-293, showing IC50 values greater for Hek-293 compared to Hep-2 and HeLa cells, which suggests a selectivity of propolis for the tumor !ines. The proteomic analysis using two-dimensional electrophoresis associated with high performance liquid chromatography coupled with mass spectrometer allowed the comparison of the protein maps of Hep-2 cell line in the absence or presence of propolis extracts in concentrations of 6 f.lg/mL (not cytotoxic) and 120 f.lg/mL (IC50). 325 spots were manually excised from the gels 2D SDS-PAGE and 177 proteins were identified. These proteins have been linked to various structural and metabolic processes, such as production and energy conversion, transport and carbohydrate metabolism, post-translational modification, protein tumover and chaperones, cytoskeletal proteins, repair proteins, among others. From the identified proteins that showed differential expression five were downregulated in the presence of propolis extract in the highest concentration (120 J.lg/mL). Only . two proteins identified in this study showed increased expression in the no cytotoxic concentration (6 J.tg/mL) ofthe red propolis extract. The results of comparative proteomic showed that the propolis interacts with a series of intracellular events and hence becomes a promising candidate to inhibit cellular growth and contribute to the different steps related to the process of carcinogenesis. Although the molecular mechanisms by which propolis interacts with the metabolism of the cells remain unknown, additional studies will better elucidate the antitumor and antioxidant activities here observed.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A fenstatina, quimicamente designada de 4-metoxifenil-3,4,5-trimetoxifenilmetanona, denominada RR07, Ã uma bisarilcetona de esqueleto estilbenÃide que pode ser obtida a partir da combretastatina A4, com reconhecida atividade citotÃxica, por meio da oxidaÃÃo de Jacobsen. Dentre as muitas atividades desencadeadas pelos estilbenos destacam-se atividade antiangiogÃnica, citotÃxica e antitumoral. Para avaliar o seu potencial antineoplÃsico, um estudo farmacolÃgico de suas propriedades anticÃncer foi realizado em vÃrios modelos biolÃgicos. Utilizando o ensaio do MTT foi feito um estudo comparativo da citotoxicidade de molÃculas estilbenÃides com estruturas relacionadas ao composto RR07, onde foi observado que a presenÃa do anel A (3,4,5-trimetoxifenil) Ã essencial para a atividade citotÃxica da molÃcula. Determinou-se inicialmente a atividade citotÃxica, frente a 13 linhagens tumorais pelo ensaio de reduÃÃo do MTT sendo testados 11 compostos, (RR01, RR02, RR03, RR04, RR05, RR06, RR07, RR08, RR09, RR10, RR11), onde o estilbenÃide RR07 destacou-se como um dos mais citotÃxicos apresentando valores de CI50 que variaram de 0,009 a 17,49 M. Posteriormente, os estudos de mecanismo de aÃÃo com o RR07 nas concentraÃÃes de 0,25; 0,50; 1,00; 2,00 e 4,00 M, revelaram reduÃÃo, de forma concentraÃÃo-dependente, na viabilidade celular pelos mÃtodos do azul de tripan e de BrdU (bromodeoxiuridina). As anÃlises morfolÃgicas feitas por hematoxilina/eosina mostraram nÃcleos metafÃsicos, onde no ensaio de incorporaÃÃo por brometo de etÃdio/laranja de acridina evidenciou-se morte celular por apoptose nas concentraÃÃes de 0,25 e 0,50 M, com cÃlulas em necrose nas concentraÃÃes de 1,00; 2,00 e 4,00 M, destacando-se alteraÃÃes como desintegraÃÃo membranar e picnose nuclear, nas concentraÃÃes de 0,25 M e 1,00 M, respectivamente. Nos ensaios por citometria de fluxo foi observado fragmentaÃÃo do DNA com parada de ciclo na fase G2/M a partir da concentraÃÃo 0,25 M. A anÃlise pelo ensaio do cometa, para o RR07 revelou atividade genotÃxica do tipo concentraÃÃo-dependente entre cÃlulas mononucleadas de sangue perifÃrico (PBMC), principalmente em 2,00 e 4,00 M. A avaliaÃÃo do RR07 no ensaio com tubulina isolada revelou inibiÃÃo na polimerizaÃÃo da mesma em uma concentraÃÃo de 10 M. A anÃlise antitumoral evidenciou inibiÃÃo de 30,9% e 48,19%, respectivamente, para as doses de 20 e 40 mg/kg/dia de RR07 por via intraperitoneal (ip), e 55,68% de inibiÃÃo para a associaÃÃo de 10 mg/kg/dia de 5-fluorouracil com 20 mg/kg/dia de RR07 (ip), em camundongos transplantados com Sarcoma 180, onde se verificou reduÃÃo no crescimento tumoral e alteraÃÃes renais iniciais e reversÃveis. Desta forma, a fenstatina, RR07, apresenta-se como uma proposta de ferramenta farmacolÃgica Ãtil para a pesquisa de novos derivados. / The phenstatin, chemically known as 4-methoxyphenyl-3,4,5-trimetoxiphenylmethane, was called in the present study as RR07. This compound is a bisarylketone with stilbenoid skeleton obtained from combretastatin A4, with recognized cytotoxic and antineoplasic activities. Then, a detailed study of RR07 anticancer properties was conducted in several biological models. The cytotoxic activity of eleven compounds (RR01, RR02, RR03, RR04, RR05, RR06, RR07, RR08, RR09, RR10, RR11) was determined against thirteen tumor cell lines by MTT assay. Structure-activity relationship pointed out that the presence of ring A (3,4,5-trimethoxiphenyl) is essential for the cytotoxic potential. The RR07 was one of the most cytotoxic compounds, showing IC50 values ranging from 0.009 to 17.49 ÂM. Investigations on mechanism of action (0.25, 0.50, 1.00, 2.00 and 4.00 ÂM) showed a concentration-dependent manner cell viability reduction (trypan blue dye exclusion test) and proliferation decreasing (BrdU assay). Morphological alterations determined by hematoxylin/eosin and acridine orange/ethidium bromide fluorescent double staining methods indicated an increased number of apoptotic cells at lowest concentrations (0.25 and 0.50 ÂM) and necrotic cells at higher concentrations (1.00, 2.00 and 4.00 ÂM). Flow cytometry analyses showed that RR07 induced DNA fragmentation and cell cycle arrest at G2/M starting at 0.25 ÂM. In the comet assay performed with human peripheral blood mononuclear cells (PBMC), RR07 caused DNA strand breaks only at higher concentrations (2.00 and 4.00 ÂM). Experiments with isolated tubulin, RR07 also induced tubulin polymerization inhibition in a concentration of 10 μM. In vivo antitumor experiments showed that Sarcoma 180 transplanted-mice treated with RR07 intraperitoneally (ip) presented a tumor growth inhibition ratios of 30.9% and 48.19% (20 mg/kg/day and 40 mg/kg/day, respectively) and inhibition of 55.68% in associated treatment (5-Fluoruracil 10 mg/kg/day + RR07 20 mg/kg/day). Histopathological analyses of kidneys, spleen and livers revealed incipient and reversible alterations. In summary, RR07 can be considered as a pharmacological useful tool as well as a lead molecule to obtain novel compounds with low toxicity and promising antitumor properties.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第15397号 / 工博第3276号 / 新制||工||1493(附属図書館) / 27875 / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 田畑 泰彦, 教授 岩田 博夫, 教授 木村 俊作 / 学位規則第4条第1項該当

Submitted by Isaac Francisco de Souza Dias (isaac.souzadias@ufpe.br) on 2016-04-19T17:00:31Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO Pâmella Grasielle Vital Dias de Souza.pdf: 2639956 bytes, checksum: 17a53d3582f15045bc389b608a00443f (MD5) / Made available in DSpace on 2016-04-19T17:00:31Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO Pâmella Grasielle Vital Dias de Souza.pdf: 2639956 bytes, checksum: 17a53d3582f15045bc389b608a00443f (MD5) Previous issue date: 2013-02-27 / FACEPE / Cnidoscolus urens pertence à família das Euphorbiaceae que é considerada uma das seis maiores famílias de Gimnospermas do bioma Caatinga. Esta espécie conhecida popularmente como urtiga branca, em levantamentos etnobotânicos realizados com populares da região do Nordeste, aparece com boa frequência e com o relato de diversas atividades biológicas como anti-inflamatória, antitumoral, antimicrobiana e analgésica. Portanto esta dissertação teve como objetivo, determinar o perfil fitoquímico dos extratos aquoso, N- butanólico e acetato de etila de C. urens, a atividade in vitro dos extratos aquoso e etanólico de C. urens e atividade antitumoral in vivo dos mesmos extratos de C. urens frente à linhagem celular HELA. Assim, para avaliar a eficácia das atividades descritas pela população, iniciou- se a investigação dos constituintes metabólitos secundários produzidos por C. urens através do método de cromatografia de camada delgada (CCD). A citotoxicidade foi determinada pelo método de MTT e para a determinação da atividade antitumoral in vivo, foram induzidos carcinoma de Ehrlich experimentais em camundongos Swiss, a determinação do perfil hematológico foi obtida através de contagem automática das células vermelhas e o perfil bioquímico foi determinado por métodos enzimáticos. Os extratos aquoso, N- butanólico e acetato de etila revelaram a presença de metabólitos majoritários tais como: Flavonóides, açúcares redutores e terpenóidess, além de outros compostos como cumarinas e taninos que apresentaram- se em menor concentração. Os extratos aquoso e etanólico foram efetivos na inibição do crescimento do tumor sólido de carcinoma de Ehrlich (84.4% e 79.2%, respectivamente) inclusive melhorando os parâmetros bioquímicos, sendo mantidos os níveis de ureia, creatinina, colesterol total, HDL-colesterol, glicose e triglicerídios e hematológicos para células sanguíneas vermelhas, células brancas e hemoglobina, indicando uma melhora na resposta imunológica dos animais tratados com os extratos. Os extratos aquoso e etanólico de C. urens não mostraram toxicidade in vitro frente à células HELA, nas concentrações testadas 12,5; 25; 50 e 100 μg/ mL, no entanto, apresentaram potencial antioxidante >50% para as concentrações de 50; 100; 200 e 500 μg/ mL. Diante desses resultados podemos concluir que os extratos aquosos e etanólico C. urens foram eficazes em inibir o crescimento do tumoral. / Cnidoscolus urens belongs to the family Euphorbiaceae which is considered one of the six largest families of gymnosperms of biome Caatinga from Brazil. This species are commonly known as urtiga branca and appears with good frequency and reporting of various biological activities such as anti-inflammatory, antitumor, antibacterial and analgesic in ethnobotanical surveys conducted in Northeast region. Therefore, this thesis aimed to determine the phytochemical profile of aqueous, butanolic and ethyl acetate of C. urens and in vivo antitumoral activity of aqueous and ethanolic extracts of C. urens and in vitro cytotoxic activity of same extracts C. urens in Hela cell line. Thus, to assess the efficacy of proposed activities for this work, it was started the research of metabolites produced by C. urens by thin layer chromatography (TLC) method, cytotoxicity was determined by the MTT method and solid tumors were induced in mice to determine the in vivo antitumoral activity, blood sampling at the orbital plexus was conducted in order to perform hematological and biochemical profile by automated cell count and enzymatic methods, respectively. The aqueous extracts, butanolic and ethyl acetate, revealed the presence of major metabolites such as flavonoids, terpenes and reducing sugars, and other compounds such as coumarins and tannins that are present in lower concentrations. The aqueous and ethanolic extracts were effective in inhibiting tumor growth (84.4% and 79.2%, respectively) and also improving biochemical (maintenance of urea, creatinine, total cholesterol, HDL-cholesterol, triglycerides and glucose levels) and hematologic parameters (red blood cells, white blood cells and hemoglobin), which indicate an improvement of the immune response of animals treated with the extracts. The aqueous and ethanolic extracts of C. urens showed no toxicity in vitro against the Hela cells, otherwise, they showed potential antioxidant activity higher than 50% at concentrations of 50, 100, 200 and 500 mg/mL. From these results we conclude that the aqueous and ethanol extracts of Cnidoscolus urens were effective in inhibiting the growth of Ehrlich tumor models of solids.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18157号 / 医博第3877号 / 新制||医||1003(附属図書館) / 31015 / 京都大学大学院医学研究科医学専攻 / (主査)教授 武藤 学, 教授 清水 章, 教授 生田 宏一 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Signal transducer and activator of transcription (STAT) is a family of intracellular proteins that are responsible for carrying the signal from the cell surface to the nucleus in response to specific ligands. Once in the nucleus, STATs activate the transcription of specific genes. To date, seven human STATs have been identified. Among these STATs, STAT3 is considered as oncogenic. It activates genes that block apoptosis and inhibits antitumor immune responses (1). STAT3 is also essential in early embryogenesis and plays a role in cell growth and survival, differentiation and apoptosis depending on the target tissue. Analysing STAT3 signalling provides insights into pathology and can be used as a tool for diagnosis, prognosis and therapy development. Traditionally, western blot has been used to analyse cell signalling but it is impractical in analysing rare cell populations or providing information at the single cell level. Moreover, it is a demanding and time consuming technique that offers qualitative and less sensitive analysis. The rapid evolution in the multi-parametric flow cytometry and the availability of both epitope specific antibodies and sophisticated software facilitate the wide application of this technology in cell signalling studies. Flow cytometry has the ability to resolve different subcellular sets in a heterogeneous population, collects data at a single cell level and correlates multiple markers simultaneously. However, it requires highly standardized protocols for maximal sensitivity. The aim of this study was to assess the dose and the time response of both total STAT3 and pSTAT3 to in vitro stimulation with either IL-6 or IL-10 in peripheral blood mononuclear cells (PBMC). This assessment was done using both the flow cytometry and the western blot techniques. The results of this study showed that lower doses of IL-6 (1 & 10 ng/ml) were not sufficient to induce phosphorylation of STAT3. However, following stimulation with 100 ng/ml of IL-6, no significant change in the level of total STAT3 could be detected in either lymphocytes or monocytes from 3 different donors using either the FC500 or the Accuri cytometer. Using the FC500 cytometer, a small but insignificant increase in the pSTAT3 was seen in the lymphocytes and monocytes. A significant increase in STAT3 phosphorylation was only observed for monocytes after 15 minutes stimulation with 100 ng/ml of IL-6 using the Accuri flow cytometer. xii When the fluorescent labelled antibodies used in the flow cytometric assays were used for western blot probing, western blot analysis of stimulated cell lysates with 100 ng/ml IL-6 detects proteins of a low molecular weight than STAT3 or pSTAT3 which may explain the flow cytometric results of IL-6 stimulation. In IL-10 stimulation experiments, lower doses (1 and 10 ng/ml) tested by flow cytometric and western blot techniques demonstrated insignificant STAT3 phosphorylation induction. Following stimulation with either 50 or 100 ng/ml IL-10, no significant change in the total STAT3 was seen in either lymphocytes or monocytes when using the Accuri flow cytometer. However, stimulation with 100 ng/ml IL-10 induces STAT3 phosphorylation from 10 minutes through 30 minutes in both lymphocytes and monocytes. Longer times were required and high inter-individual variability was noticed for the activation of STAT3 after stimulation with 50 ng/ml IL-10. By using different antibodies from those used in the flow cytometric assay; the western blot results were comparable with the flow cytometric findings following stimulation with 100 ng/ml IL-10. The addition of phosphatase inhibitors during the flow cytometric protocol didn’t show any increase in the STAT3 phosphorylation. However, using paraformaldehyde for fixation and methanol for permeabilisation significantly decreased the mean fluorescence intensity of the PE conjugated antibodies comparing to the BD commercial fixation and permeabilisation buffers. The onset and the signal intensity of “in house” chemiluminescence mixture for western blot detection of STAT3 were comparable to the commercial ECL reagent used. However, the background of the “in house” mixture increased with time and was higher than with the commercial product. Upon longer exposure, the background increased enough to cause signal loss. In spite of the number of advantages of the flow cytometric assay compared to the western blot assay, these results are highly dependent on the specificity and the selectivity of the used antibodies. Furthermore, flow cytometry requires a highly standardized protocol to be able to assess the normal level of signalling proteins which could be later applied to detect abnormalities. It is suggested that the antibodies used in the flow cytometric assay be tested by western blot to confirm their selective detection of the target protein before their use in the flow cytometric analysis. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Pharmacology / unrestricted

No / A novel series of 1,4-disubstituted chloroethylaminoanthraquinones, containing alkylating chloroethylamino functionalities as part of a rigid piperidinyl or pyrrolidinyl ring-system, have been prepared. The target compounds were prepared by ipso-displacement of halides of various anthraquinone chromophores by either hydroxylated or chlorinated piperidinyl- or pyrrolidinyl-alkylamino side chains. The chloroethylaminoanthraquinones were shown to alkylate guanine residues of linearized pBR322 (1¿20 ¿M), and two symmetrically 1,4-disubstituted anthraquinones (compounds 14 and 15) were shown to interstrand cross-link DNA in the low nM range. Several 1,4-disubstituted chloroethylaminoanthraquinones were potently cytotoxic (IC50 values: ¿40 nM) in human ovarian cancer A2780 cells. Two agents (compounds 18 and 19) exhibited mean GI50 values of 96 nM and 182 nM, respectively, in the NCI human tumor cell line panel. Derivatization of the potent DNA cross-linking agent 15 to an N-oxide resulted in loss of the DNA unwinding, DNA interstrand cross-linking and cytotoxic activity of the parent molecule.

Yes / An efficient four-step synthesis of tetracyclic lactones from 1,4-benzodioxine-2-carboxylic acid was developed. Ellipticine derivatives exhibit antitumor activity however only a few derivatives without carbazole subunit have been studied to date. Herein, several tetracyclic lactones were synthesized and biologically evaluated. Several compounds (2a, 3a, 4a and 5a) were found to be inhibitors of the Kras-Wnt pathway. The lactone 2a also exerted a potent inhibition of Tau protein translation and was shown to have capacity for CYP1A1-bioactivation. The results obtained are further evidence of the therapeutic potential of tetracyclic lactones related to ellipticine. Molecular modeling studies showed that compound 2a is inserted between helix α3 and α4 of the KRas protein making interactions with the hydrophobic residues Phe90, Glu91, Ile9364, Hie94, Leu133 and Tyr137and a hydrogen bond with residue Arg97. / The Spanish Minister (CTQ2011-29285-C02-02) the SGR(2014)-1017 Generalitat de Catalunya and the Laboratories Servier (France)

Radiossensibilizadores são definidos como agentes químicos que aumentam a sensibilidade das células hipóxicas à radiação, visando o aumento da eficácia da radioterapia no tratamento do câncer. Alguns Carboxilatos de Rh (II) e compostos nitroimidazólicos têm sido testados como radiossensibilizadores em doses elevadas de radiação, obtendo-se resultados significativos. Neste trabalho, foram sintetizados vários carboxilatos e um amidato de Rh (II): propionato, butirato, trifluoroacetato, citrato e trifluoroacetamidato, assim como os seus respectivos adutos com metronidazol, de fórmula geral: [Rh2(RCOO)4metro2] (R = CH3, C2H5, C3H7, C5 H7O5, e CF3) para o caso dos carboxilatos e [Rh2(CF3CONH) 4 metro2] para o aduto de trifluoroacetamidato. Os compostos foram caracterizados por análise elementar, espectroscopia eletrônica, infravermelho e de ressonância magnética nuclear de próton. O resultado desta caracterização permitiu estabelecer as rotas de síntese confirmando a formação dos carboxilatos tipo ponte e a presença do metronidazol nas posições axiais, numa relação 1:2. O efeito radiossensibilizador desses complexos de Rh (II) foi testado in vitro, irradiando-se, em atmosfera hipóxica, células de ovário de hamster chinês (CHO k1), na presença dos complexos, utilizando-se raios gama provenientes de uma fonte de 60Co, com doses de 2,7 e 4,3 Gy. Foi realizado teste de citotoxicidade para determinar as concentrações atóxicas de cada composto, eliminando a possibilidade de morte celular devido ao efeito tóxico dos mesmos. Na dose 2,7 Gy não houve nenhum efeito interessante; já com a dose de 4,3 Gy o [Rh2(CH3 COO)4] mostrou uma atividade radiossensibilizadora maior do que nos demais complexos. Os resultados foram semelhantes aos obtidos na literatura com doses de radiação até 10 vezes maiores. Devido à ausência de mudanças significativas no efeito radiossensibilizador entre os carboxilatos e amidato e seus respectivos adutos com metronidazol, foi determinada a constante de formação destes últimos, demonstrando que os mesmos sofrem decomposição quando em solução aquosa diluída. / Radiosensitizers are chemical agents that enhance the radiation sensitivity of hipoxic tumor cells aiming to better radiotherapy efficacy in the treatment of cancer. Some Rhodium (II) carboxylates and its adducts with nitroimidazole derivatives, have been tested as radiosensitizers in high doses of radiation, being obtained significant results. In this work, several Rhodium carboxylates and one Rhodium amidate previously described were synthesized: propionate, trifluoroacetate, citrate and , trifluoroacetamidate, as well as their respective adducts with nitroimidazole of general formula [Rh2(RCOO)4metro2] for the carboxylates and [Rh2(CF3CONH)4metro2] for the trifluoroacetamidate adduct. The compositions where characterized by elementary analysis, electronic and infrared spectroscopy and proton nuclear magnetic resonance. The results of that characterization allowed us to establish the synthesis routes and confirm the bridge type structure of the Rodhium compounds, beyond the presence of the metronidazole at the axial positions in the proportions of 1:2. The radiosensitizing effects of these Rh (II) complexes were tested in vitro by irradiation of Chinese hamster (CHO k1) cells under hipoxic atmosphere in the presence of the complexes, using gamma rays from a 60Co source and doses of 2,7 and 4,3 Gy. A cytotoxicity test has been performed to determinate the non-toxic concentrations of these compounds, in order to rule out the possibility of cellular death induced by the complexe´s cytotoxicity. A 2,7 Gy dose showed no interesting effects but under a 4,3 Gy dose, the complex Rh2(CH3 COO)4 showed a higher radiosensitizing effect than the order compounds and close to previously reported effects which required high radiation doses. As there was not a significant change in the radiosensitizing effect between the carboxylate and the amidate and their respective metronidazole adducts it was performed the measurement of the formation constant of that adducts. The results of that measurements gave evidence of adduct decomposition when in dilute aqueous solution.

Radiossensibilizadores são definidos como agentes químicos que aumentam a sensibilidade das células hipóxicas à radiação, visando o aumento da eficácia da radioterapia no tratamento do câncer. Alguns Carboxilatos de Rh (II) e compostos nitroimidazólicos têm sido testados como radiossensibilizadores em doses elevadas de radiação, obtendo-se resultados significativos. Neste trabalho, foram sintetizados vários carboxilatos e um amidato de Rh (II): propionato, butirato, trifluoroacetato, citrato e trifluoroacetamidato, assim como os seus respectivos adutos com metronidazol, de fórmula geral: [Rh2(RCOO)4metro2] (R = CH3, C2H5, C3H7, C5 H7O5, e CF3) para o caso dos carboxilatos e [Rh2(CF3CONH) 4 metro2] para o aduto de trifluoroacetamidato. Os compostos foram caracterizados por análise elementar, espectroscopia eletrônica, infravermelho e de ressonância magnética nuclear de próton. O resultado desta caracterização permitiu estabelecer as rotas de síntese confirmando a formação dos carboxilatos tipo ponte e a presença do metronidazol nas posições axiais, numa relação 1:2. O efeito radiossensibilizador desses complexos de Rh (II) foi testado in vitro, irradiando-se, em atmosfera hipóxica, células de ovário de hamster chinês (CHO k1), na presença dos complexos, utilizando-se raios gama provenientes de uma fonte de 60Co, com doses de 2,7 e 4,3 Gy. Foi realizado teste de citotoxicidade para determinar as concentrações atóxicas de cada composto, eliminando a possibilidade de morte celular devido ao efeito tóxico dos mesmos. Na dose 2,7 Gy não houve nenhum efeito interessante; já com a dose de 4,3 Gy o [Rh2(CH3 COO)4] mostrou uma atividade radiossensibilizadora maior do que nos demais complexos. Os resultados foram semelhantes aos obtidos na literatura com doses de radiação até 10 vezes maiores. Devido à ausência de mudanças significativas no efeito radiossensibilizador entre os carboxilatos e amidato e seus respectivos adutos com metronidazol, foi determinada a constante de formação destes últimos, demonstrando que os mesmos sofrem decomposição quando em solução aquosa diluída. / Radiosensitizers are chemical agents that enhance the radiation sensitivity of hipoxic tumor cells aiming to better radiotherapy efficacy in the treatment of cancer. Some Rhodium (II) carboxylates and its adducts with nitroimidazole derivatives, have been tested as radiosensitizers in high doses of radiation, being obtained significant results. In this work, several Rhodium carboxylates and one Rhodium amidate previously described were synthesized: propionate, trifluoroacetate, citrate and , trifluoroacetamidate, as well as their respective adducts with nitroimidazole of general formula [Rh2(RCOO)4metro2] for the carboxylates and [Rh2(CF3CONH)4metro2] for the trifluoroacetamidate adduct. The compositions where characterized by elementary analysis, electronic and infrared spectroscopy and proton nuclear magnetic resonance. The results of that characterization allowed us to establish the synthesis routes and confirm the bridge type structure of the Rodhium compounds, beyond the presence of the metronidazole at the axial positions in the proportions of 1:2. The radiosensitizing effects of these Rh (II) complexes were tested in vitro by irradiation of Chinese hamster (CHO k1) cells under hipoxic atmosphere in the presence of the complexes, using gamma rays from a 60Co source and doses of 2,7 and 4,3 Gy. A cytotoxicity test has been performed to determinate the non-toxic concentrations of these compounds, in order to rule out the possibility of cellular death induced by the complexe´s cytotoxicity. A 2,7 Gy dose showed no interesting effects but under a 4,3 Gy dose, the complex Rh2(CH3 COO)4 showed a higher radiosensitizing effect than the order compounds and close to previously reported effects which required high radiation doses. As there was not a significant change in the radiosensitizing effect between the carboxylate and the amidate and their respective metronidazole adducts it was performed the measurement of the formation constant of that adducts. The results of that measurements gave evidence of adduct decomposition when in dilute aqueous solution.