Thesis (M.S.)--Tennessee Technological University, 2009. / Title from title page screen (viewed on Feb. 26, 2010). Bibliography: leaves 75-79.

Iron is the most abundant trace mineral in the body and an essential element in all living systems. In humans, iron is found at the active site of a number of key proteins involved in oxygen transport, metabolism, respiration and DNA synthesis. The development of agents that inhibit the iron dependent enzyme ribonucleotide reductase (RR) is an established strategy in cancer therapy. Hydroxyurea is the first agent to target RR by inactivating the nonheme iron centre, but its efficacy appears to be limited to myeloproliferative disorders. Currently, Triapine™ (3-aminopyridine-2-carboxaldehyde thiosemicarbazone) is a successful iron chelator, which inhibits enzyme activity and cell growth in vitro at 100 to 1000 fold lower concentrations than hydroxyurea. Preclinical studies suggested that Triapine™ may be an attractive agent to move into clinical development in patients with cancer. Therefore, heterocyclic thiosemicarbazones as well as their iron complexes are an important series of compounds, which may show promising anticancer properties. Thiosemicarbazone derivatives of the HDpT (di-2-pyridyl ketone-3-thiosemicarbazone), HBpT (2-benzoylpyridine-3-thiosemicarbazone), HNBpT (2-(3΄-nitrobenzoyl)pyridine-3-thiosemicarbazone) and HApT (2-acetylpyridine-3-thiosemicarbazone) series and their FeII and FeIII complexes were synthesised and characterised by elemental analyses, UV-vis spectroscopy, NMR spectroscopy, IR (ATR, attenuated total reflectance), EPR spectroscopy, electrochemistry, and X-ray crystallography. To further understand their physical and chemical properties, other transition metal Mn, Co, Ni, Cu and Zn complexes of the HDpT and HBpT analogues were synthesised and characterised. The X-ray crystal structure of trivalent Fe complexes and divalent (Mn, Ni, Cu and Zn) complexes were determined. The HDpT, HBpT, HNBpT and HApT analogues of thiosemicarbazone class of iron chelators have the capability to bind metal ions as tridentate (N,N,S) ligands, forming 2:1 ligand:Fe complexes with an N4S2 octahedral coordination sphere. During the course of investigation, the formation constants of MnII, NiII, CuII and ZnII complexes of these series were determined by spectrophotometric competition titration with nitrilotriacetic acid (NTA). Several interesting aspects of the coordination chemistry of these iron chelators have also been discovered To better understand the biological activities of these ligands, the chemical and the physical properties of these ligands and their iron and other transition metal complexes have been studied. Chiefly, we are concerned with their ability to cross the cell membrane (lipophilicity) as well as the redox chemistry of their metal complexes. The lipophilicity of the ligands was determined by direct partitioning between 1-octanol and water at pH 7.4. The Fe complexes of the HApT series exhibit lower redox potentials than their corresponding HDpT, HBpT and HNBpT complexes and higher anticancer activity indicating a link between their Fe redox reactivity and their biological properties.

Iron is the most abundant trace mineral in the body and an essential element in all living systems. In humans, iron is found at the active site of a number of key proteins involved in oxygen transport, metabolism, respiration and DNA synthesis. The development of agents that inhibit the iron dependent enzyme ribonucleotide reductase (RR) is an established strategy in cancer therapy. Hydroxyurea is the first agent to target RR by inactivating the nonheme iron centre, but its efficacy appears to be limited to myeloproliferative disorders. Currently, Triapine™ (3-aminopyridine-2-carboxaldehyde thiosemicarbazone) is a successful iron chelator, which inhibits enzyme activity and cell growth in vitro at 100 to 1000 fold lower concentrations than hydroxyurea. Preclinical studies suggested that Triapine™ may be an attractive agent to move into clinical development in patients with cancer. Therefore, heterocyclic thiosemicarbazones as well as their iron complexes are an important series of compounds, which may show promising anticancer properties. Thiosemicarbazone derivatives of the HDpT (di-2-pyridyl ketone-3-thiosemicarbazone), HBpT (2-benzoylpyridine-3-thiosemicarbazone), HNBpT (2-(3΄-nitrobenzoyl)pyridine-3-thiosemicarbazone) and HApT (2-acetylpyridine-3-thiosemicarbazone) series and their FeII and FeIII complexes were synthesised and characterised by elemental analyses, UV-vis spectroscopy, NMR spectroscopy, IR (ATR, attenuated total reflectance), EPR spectroscopy, electrochemistry, and X-ray crystallography. To further understand their physical and chemical properties, other transition metal Mn, Co, Ni, Cu and Zn complexes of the HDpT and HBpT analogues were synthesised and characterised. The X-ray crystal structure of trivalent Fe complexes and divalent (Mn, Ni, Cu and Zn) complexes were determined. The HDpT, HBpT, HNBpT and HApT analogues of thiosemicarbazone class of iron chelators have the capability to bind metal ions as tridentate (N,N,S) ligands, forming 2:1 ligand:Fe complexes with an N4S2 octahedral coordination sphere. During the course of investigation, the formation constants of MnII, NiII, CuII and ZnII complexes of these series were determined by spectrophotometric competition titration with nitrilotriacetic acid (NTA). Several interesting aspects of the coordination chemistry of these iron chelators have also been discovered To better understand the biological activities of these ligands, the chemical and the physical properties of these ligands and their iron and other transition metal complexes have been studied. Chiefly, we are concerned with their ability to cross the cell membrane (lipophilicity) as well as the redox chemistry of their metal complexes. The lipophilicity of the ligands was determined by direct partitioning between 1-octanol and water at pH 7.4. The Fe complexes of the HApT series exhibit lower redox potentials than their corresponding HDpT, HBpT and HNBpT complexes and higher anticancer activity indicating a link between their Fe redox reactivity and their biological properties.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A talidomida, anteriormente usada para aliviar desconfortos gÃstricos da gravidez, atualmente à usada para tratamento do cÃncer e de doenÃas inflamatÃrias. VÃrios anÃlogos ftalimÃdicos da talidomida tem sido pesquisados quanto a sua atividade antiangiogÃnica e imunomodulatÃria. Em estudos prÃvios, estes anÃlogos mostraram ausÃncia de atividade imunossupressora. O trabalho determinou, inicialmente, a atividade citotÃxica, de oito anÃlogos ftalimÃdicos da talidomida, frente a linhagens tumorais e de cÃlulas mononucleadas isoladas de sangue perifÃrico (CMSP) apÃs 72h de incubaÃÃo. Nenhum dos compostos desencadeou atividade citotÃxica in vitro, induÃÃo de hemÃlise em eritrÃcitos e potencial em induzir dano à fita de DNA, portanto nÃo foram genotÃxicos em CMSP humanas. O efeito antitumoral (in vivo) da talidomida e dos oito anÃlogos foi analisado em camundongos transplantados com o tumor Sarcoma 180 e tratados na dose 50mg/Kg/7 dias, via i.p. A inibiÃÃo do crescimento tumoral foi significante apenas para talidomida (53,5%) e anÃlogos SC-10 e SC-11 (67,9% e 67,4%, respectivamente), p<0,05. A anÃlise histopatolÃgica dos ÃrgÃos dos animais mostrou que a talidomida e seus anÃlogos provocam efeitos tÃxicos moderados, principalmente no fÃgado, mas esses podem ser considerados como reversÃveis. Os estudos acerca do mecanismo de aÃÃo foram aprofundados usando cÃlulas isoladas do Sarcoma 180, apÃs 72 horas de incubaÃÃo, nas doses de 10, 50 e 100Âg/mL, por citometria de fluxo, atravÃs dos seguintes ensaios: 1- AvaliaÃÃo da integridade de membrana, viabilidade celular e concentraÃÃo de cÃlulas; 2- DeterminaÃÃo do conteÃdo de DNA nuclear da cÃlula. Todos os compostos induziram a perda de integridade de membrana celular e fragmentaÃÃo internucleossomal do DNA nas maiores concentraÃÃes, indicando presenÃa de cÃlulas apoptÃticas em estÃgios finais ou em processo de necrose secundÃria. A avaliaÃÃo do potencial antiangiogÃnico, pelo ensaio do Wound Healing revelou que para a linhagem endotelial (HUVEC) o anÃlogo SC-10 causou uma inibiÃÃo maior (65,28%  1,58), enquanto que na linhagem tumoral o efeito maior foi do anÃlogo SC-11 (98,51%  0,25). A talidomida nÃo foi capaz de reduzir a migraÃÃo celular em nenhuma das linhagens testadas. No ensaio da membrana corioalantÃide (CAM), potencial antiangiogÃnico foi observado para os anÃlogos SC-10 e SC-11(5mg/mL), que inibiram o nÃmero de vasos (12, 88%  2,3 e 14,81%  3,3), a Ãrea de neovascularizaÃÃo (13,14%  1,7 e 14,26%  1,7) e o comprimento total de vasos em mm2 (9,19%  1,5 e 9,86%  1,9). A talidomida, nÃo foi capaz de inibir a vascularizaÃÃo embrionÃria. O efeito antitumoral (in vivo) da talidomida e anÃlogos SC-10 e SC-11 foi analisado em camundongos transplantados com o tumor Sarcoma 180, tratados na dose 50mg/Kg/10 dias, via i.p. A inibiÃÃo do crescimento tumoral para a talidomida (56.6%) e para os anÃlogos SC-10 e SC-11 (48,2% e 41,3%, respectivamente), p<0,05. A imunocoloraÃÃo de cÃlulas endoteliais intratumorais com CD-31, revelou-se, na forma de densidade microvascular, diminuÃda nos grupos tratados com anÃlogos SC-10 e SC-11 (64,59% e 46,51%), mas nÃo nos grupos tratados com a talidomida. Estes resultados, unidos a estudos prÃvios de imunomudulaÃÃo sugerem imunidade antitumoral e antiangiogÃnica, dependente de cÃlulas T, para os anÃlogos ftalimÃdicos. / The thalidomide was previously used to relieve gastric discomforts during pregnancy, and currently it is used for cancer treatment and inflammatory illnesses. Various phthalimides analogues of thalidomide have been researched for its antiangiogenic and immunemodulatory activity. In previous studies, these analogues showed absence of immunesuppressor activity. In this context, this work initially determined the cytotoxic activity of eight phthalimides analogues of thalidomide, in a series of cancer cell lines and of isolated peripheral mononuclear blood cells (PMBC) after 72h of incubation. None of compounds revealed cytotoxic activity in vitro in cancer cell lines and hemolytic activity towards of PBMC. They also showed no potential damage to the DNA strand, therefore they were not considered genotoxic towards human PMBC. The antitumor effect (in vivo) of thalidomide along with eight analogues was analyzed in mice transplanted with the Sarcoma 180 tumor and treated in a dose of 50mg/Kg/7 days, i.p. The inhibition of the tumor growth was only significant in mice treated with thalidomide (53.5%) and the analogues SC-10 and SC-11 (67.9% and 67.4%, respectively), p< 0,05. The histopathological analysis of the animalsâ organs showed mainly that thalidomide and its analogues cause moderate toxic effects, mostly in the liver, but these can be considered reversible. The studies concerning the mechanism of action were deepened using isolated cells from the Sarcoma 180, after 72 hours of incubation, in the doses of 10, 50 and 100Âg/mL. The following flow cytometry assays were carried out: 1- Evaluation of the membrane integrity, cellular viability and concentration of cells; 2- Determination of the nuclear DNA content. All the compounds led to the loss of membrane cell integrity and it was found internucleossomal DNA fragmentation in the higher concentrations, indicating the presence of cells with late stage apoptotic characteristics or in the process of secondary necrosis. The evaluation of the antiangiogenic potential, with the Wound Healing assay revealed that for the endothelial cell line (HUVEC) the analogue SC-10 caused a greater inhibition (65.28%  1,58), whereas in the tumor cell line the highest effect was of the analogue SC-11 (98.51%  0,25). The thalidomide was not capable of reducing cellular migration in none of the tested cell lines. In the chorioallantoic membrane assay (CAM), an antiangiogenic potential was observed with analogous SC-10 and SC-11 (5mg/mL), where there was an inhibition in the number of vessels (12, 88%  2,3 and 14.81%  3,3), the area of neovascularization (13.14%  1,7 and 14.26%  1,7) and the total length of vessels in mm2 (9.19%  1,5 and 9.86%  1,9). The thalidomide was not capable of inhibiting embryonic vascularization. The antitumor effect (in alive) of thalidomide and the analogues SC-10 and SC-11 was analyzed in mice transplanted with the Sarcoma 180 tumor, treated with the dose of 50mg/Kg/10 days, i.p. It was observed inhibition of the tumor growth in the thalidomide treatment (56,6%) and for analogues SC-10 and SC-11 (48.2% and 41.3%, respectively), p< 0,05. The immunostaining of intratumor endothelial cells with CD-31, showed, in the form of microvascular density, reduction in the groups treated with analogues SC-10 and SC-11 (64.59% and 46.51%), but not in the groups treated with thalidomide. These results, along with previous studies of immunemodulation suggest antitumor and antiangiogenic immunity, T cells dependent, for the phthalimides analogues.

Thesis (Ph.D.)--Baylor University, 2005. / Includes bibliographical references (p. 483-494).

Thesis (M.S.)--Baylor University, 2007. / Includes bibliographical references (p. 1-6 [second group]).

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2017-05-04T19:22:54Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese Jamerson Ferreira de Oliveira.pdf: 8179635 bytes, checksum: 1f2c547f3d5adc66855c8a64ba2e148e (MD5) / Made available in DSpace on 2017-05-04T19:22:54Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese Jamerson Ferreira de Oliveira.pdf: 8179635 bytes, checksum: 1f2c547f3d5adc66855c8a64ba2e148e (MD5) Previous issue date: 2016-03-07 / Facepe / O câncer é um grave problema de saúde pública o qual afeta milhares de pessoas no mundo. Sabe-se que há uma estreita relação entre o câncer e a inflamação onde o microambiente inflamatório favorece a progressão tumoral. Baseado nessas evidências, foi proposto neste trabalho, a síntese de novas moléculas híbridas contendo as subunidades das tiossemicarbazonas e do tiofeno que detêm as atividades antitumoral e anti-inflamatória. Uma nova série de 2-tiofenotiossemicarbazonas (5-14) foi sintetizada, caracterizada e avaliada a atividade biológica. A síntese demonstrou ser eficiente onde foi possível encontrar rendimentos reacionais satisfatórios que variaram de 40-87%. A atividade antiproliferativa in vitro foi realizada através do método colorimétrico da sulforrodamina B, onde os derivados 7 (p-bromo-fenil) e 9 (p-metil-fenil) foram os que mais se destacaram. O composto 7 se destacou frente à linhagem NCIADR/ RES com GI50 1.7 μM, já o composto 9 se destacou na linhagem K-562 com GI50 <0.9 μM. O composto 7 foi eleito, dentre os demais derivados avaliados no ensaio in vitro, para o prosseguimento dos estudos. Através da citometria de fluxo foi possível evidenciar que o composto induz a exposição de fosfatidilserina (apoptose inicial), porém esse mecanismo de morte celular é independente do ciclo celular. Os estudos in vivo foram realizados utilizando o modelo de tumor de pata de Ehrlich. Das três doses utilizadas (30, 100 e 300 mg/Kg) a dose de 30 mg/Kg foi capaz de controlar o crescimento tumoral na pata dos camundongos nos dias 6 (60.6 ± 4.6), 9 (57.1 ± 5.2) e 12 (36.3 ± 6.6). Adicionalmente a atividade antitumoral, também foram realizados ensaios a fim de avaliar as atividades antinociceptiva e anti-inflamatória. O ensaio de nocicepção induzido pela formalina revelou que o composto 7 apresentou atividade nas duas fases da dor, ressaltando a dor inflamatória, onde o derivado foi capaz de reduzir o tempo de lambida da pata em 62.3, 84.30 e 100% nas doses de 30, 100 e 300 mg/Kg, respectivamente. Acerca da atividade anti - inflamatória, foi realizado o edema de orelha induzido por óleo de cróton, onde nenhuma das doses testadas foi capaz de regredir significativamente o edema produzido. O edema de pata induzido pela carragenina mostrou ação do composto, onde o edema foi reduzido em 81.9 e 83.2% nos tempos 1 e 2 horas do experimento na dose de 300 mg/Kg. Isso sugere uma ação sobre os mediadores iniciais da inflamação. O ensaio de edema de pata induzido pelo composto 48/80 confirmou essa hipótese, no qual o composto 7, após 15 minutos do inóculo do agente flogístico, demonstrou redução significativa do edema apresentando valores de 56.53% na dose de 30 mg/Kg indicando uma ação do composto sobre a serotonina e a histamina. Os estudos iniciais, realizados acerca da investigação do potencial biológico das 2-tiofeno-tiossemicarbazonas, revelaram a importância dessa classe de compostos no câncer e na inflamação. No entanto, estudos minuciosos necessitam ser realizados a fim de contribuir na descoberta de novos fármacos. / Cancer is a major public health issue which affects thousands of people worldwide. It is known that there is a close relationship between cancer and inflammation where the inflammatory microenvironment promotes tumor progression. Based on this evidence, it is proposed in this paper the synthesis of new hybrid molecules containing the subunits of thiosemicarbazone and thiophene holding the anti-tumor and anti-inflammatory activities. A new series of 2-thiophene-thiosemicarbazones (5- 14) was synthesized, characterized and evaluated to the antitumor and antiinflammatory activity. The synthesis was demonstrated efficient where it was possible to find satisfactory reaction yields ranging from 40-87%. The antiproliferative activity in vitro was performed using the colorimetric method sulforhodamine B. The derivatives 7 (p-bromophenyl) and 9 (p-methylphenyl) obtained good GI50 values. The compound 7 stood out against NCI-ADR/RES lineage (multidrug resistant ovarian) with GI50 1.7 μM, as the compound 9 stood out in the K-562 strain (leukemia) with GI50 <0.9 μM. Compound 7 was elected from among the other derivatives evaluated in vitro assay, for further studies. By flow cytometry it became clear that the compound induces phosphatidylserine exposure (early apoptosis), but this cell killing mechanism is independent of the cell cycle. In vivo studies were performed using the model Ehrlich paw tumor. Of the three doses used (30, 100 and 300 mg/Kg) dose of 30 mg/Kg was able to control tumor growth in the paw of mice on days 6 (60.6 ± 4.6), 9 (57.1 ± 5.2) and 12 (36.3 ± 6.6). In addition to antitumor activity, also forms tests performed to evaluate the antinociceptive and antiinflammatory activities. The nociception induced by formalin test revealed that the compound 7 showed activity in both phases of pain, emphasizing the inflammatory pain, where it was able to reduce the time of paw lick 62.3, 84.30 and 100% at doses of 30, 100 and 300 mg/kg, respectively. About anti-inflammatory activity was performed ear edema induced by croton oil, where any of the doses tested was able to significantly decrease edema produced. The paw edema induced by carrageenan showed activity of the compound, where the edema was reduced 81.9 and 83.2% in the first two times of the experiment at the highest dose used (saline: 18.85 ± 2.63, 32.86 ± 4.97 and 3 JF-300 mg/Kg: 3.41 ± 1.4, 1.96 ± 5.53). This suggests an action on the initial mediators of inflammation. The paw edema assay induced by compound 48/80 confirmed our hypothesis, in which the compound 7 after 15 minutes from the inoculum phlogistic agent, showed a significant reduction of edema with values of 56.53% at the dose of 30 mg/kg (saline: 71.10 ± 6.6 JF-3 and 30 mg/kg: 30.9 ± 5.75), indicating an action of the compound on the serotonin and histamine. Initial studies conducted research on the biological potential of 2-thiophene-thiosemicarbazones, showed good activity of this class of compounds in cancer and inflammation. However, detailed studies to determine the mechanism of action by which act the thiosemicarbazone, need to be performed in order to contribute to the discovery of new drugs.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-04-04T21:35:12Z No. of bitstreams: 2 Dissertação - Dayane Kelly Sabec Pereira - 2015.pdf: 7161660 bytes, checksum: 9e90c47a6af39120173e8142ccb64d21 (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-04-05T11:15:37Z (GMT) No. of bitstreams: 2 Dissertação - Dayane Kelly Sabec Pereira - 2015.pdf: 7161660 bytes, checksum: 9e90c47a6af39120173e8142ccb64d21 (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) / Made available in DSpace on 2016-04-05T11:15:37Z (GMT). No. of bitstreams: 2 Dissertação - Dayane Kelly Sabec Pereira - 2015.pdf: 7161660 bytes, checksum: 9e90c47a6af39120173e8142ccb64d21 (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) Previous issue date: 2015-09-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The increased bacterial resistance is an important factor in the number of deaths in hospitals, hampering the cure and elevating spending on assistance. Thus it is urgent to develop new drugs, synthetic or natural origin. A group of compounds that have been prominent are the thiosemicarbazones (TSCs) and semicarbazones (SCs) due to low cost of synthesis and broad spectrum of action, antifungal, antibacterial, anti-inflammatory and antiviral. In this study tests were performed with four synthesized chemical binders, denominated: H2L0; H2L1; H2L2 and H2L3 and H2L3 the four compounds complexed ligand named: Bipy-fenil-Sn, Bipy-nit-Cu, (H2L3)butil-Sn and (H2L3)bipy-Sn submitted to quantitative tests to determine the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) and also evaluated for cytotoxicity cardiomyocytes and peritoneal macrophages. The standard strains ATCC (American Type Culture Collection) used were bacteria Staphylococcus aureus and Klebsiella pneumoniae, yeast and fungi: Candida albicans, Candida tropicalis and Candida parapsilosis. The tests were performed in triplicate in 96 well plates, incubated for 24 hours at 35 ° C, with specific medium. The observed antibacterial activity of the compounds H2L1, H2L2 and H2L3 on S. aureus, presented MIC in range from 3.7 to 19.7 μg/mL; to K. pneumoniae the MICs of the compounds were over 500 μg/mL. The compound H2L3, inhibited the growth of three species of Candida tested MIC between 5.6 - 6.2 μg/mL. Because of this, the binder was chosen for complexation with metals. The complexed compounds obtained MICs 1.6 to 245.8 μg/mL. MFC tests with the compounds H2L0, H2L1 and H2L2 showed no change in the growth curve of the colonies to the three species of Candida. As for the compounds complexed MFC tests indicated a fungicidal effect of bipy-nit-Cu, bipy-fenil-Sn, only on C. albicans at concentrations of 250 μl/mL and less than 62.5 μl/mL. Cytotoxicity tests revealed that the compounds exhibit cytotoxicity under moderate conditions. In the compounds complexed with metals, antifungal activity showed up similar to H2L3 isolated compound, obtaining a satisfactory result for further research with compounds under study, presenting a great antimicrobial potential which is no prospect of a future metalodrug. / O aumento da resistência bacteriana é um fator importante no número de ocorrência de mortes em ambientes hospitalares, dificultando a cura e elevando os gastos com a assistência. Desta forma faz-se urgente o desenvolvimento de novos fármacos, sintéticos ou de origem natural. Um grupo de compostos que tem se destacado são as tiossemicarbazonas (TSCs) e as semicarbazonas (SCs), por apresentarem baixo custo de síntese e amplo espectro de ação, antifúngica, antibacteriana, antiinflamatória e antiviral. Neste trabalho foram utilizados quatro ligantes químicos sintetizados, denominados: H2L0; H2L1; H2L2 e H2L3 e quatro compostos complexados ao ligante H2L3 denominados: Bipy-fenil-Sn, Bipy-nit-Cu, (H2L3)butil-Sn e (H2L3)bipy-Sn submetidos a testes quantitativos para determinação da Concentração Inibitória Mínima (MIC) e da Concentração Fungicida Mínima (MFC) e também avaliada a citotoxidade em cardiomiócitos e macrófagos peritoneais. As cepas de padrão ATCC (American Type Culture Collection) utilizadas foram de bactérias Staphylococcus aureus e Klebsiella pneumoniae, e fungos leveduriformes: Candida albicans, Candida tropicalis e Candida parapsilosis. Os testes foram realizados em triplicata, em placas 96 poços, incubadas por 24 horas a 35ºC, com meio específico. A atividade antibactericida observada dos compostos H2L1, H2L2 e H2L3, sobre S. aureus, apresentou MIC na faixa de 3,7 a 19,7 μg/mL; para K. pneumoniae os MICs dos compostos foram superiores a 500 μg/mL. O composto H2L3, inibiu o crescimento das três espécies de Candida testadas com MIC entre 5,6 – 6,2 μg/ml. Devido a isso, este foi o ligante escolhido para a complexação com metais. Os compostos complexados obtiveram valores de MIC 1,6 a 245,8 μg/mL Os testes de MFC com os compostos H2L0, H2L1 e H2L2 não apresentaram alteração na curva de crescimento para as três espécies de Candida. Quanto aos compostos complexados, os testes de MFC apontaram um efeito fungicida do bipy-nit-Cu, bipy-fenil-Sn, somente sobre C. albicans, nas concentrações de 250 μl/mL e menores que 62,5 μl/mL. Os testes de citotoxidade revelaram que os compostos apresentam citotoxidade em condições moderadas. Nos compostos complexados com metais, a atividade antifúngica apresentou-se semelhante ao composto H2L3 isolado, obtendo um resultado satisfatório para novas pesquisas com os compostos em estudo, apresentando um ótimo potencial antimicrobiano ao qual há perspectiva de uma futura metalodroga.

Chapter One introduces molecular irnaging and the modalities available for oncological irnaging. The radioisotopes and imaging agents for Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) are discussed together with the bifunctional chelator approach for radio labelling of biomolecules. Finally, the chemistry and radioisotopes of copper are described, and copper bis(thiosemicarbazonato) complexes introduced in the context of PET irnaging. Chapter Two describes the synthesis and characterisation of novel carboxylate- and maleirnide- functionalised bis(thiosemicarbazonates) and their conjugation to biologically active molecules. Radiolabelling of a chelator-bombesin conjugate demonstrated site-specific labelling at room temperature and preliminary in vitro and in vivo studies confirmed its potential as an imaging agent. Bioconjugation to a model protein and subsequent radiolabelling was also investigated. Chapter Three introduces molecular irnaging of hypoxia with a focus on CuATSM. An overview of the currently accepted mechanism of hypoxia selectivity is presented. The emphasis is placed on the relationship between oxygenation status, uptake and retention which display cell- and tumour- line dependency. Chapter Four presents the synthesis of copper bis(thiosemicarbazonates), radiolabelled either at the metal (64CU) or at the ligand e8F or 123n for mechanistic studies. The physicochemical characteristics of the copper complexes were measured and the complexes evaluated for their in vitro hypoxia selectivity. Chapter Five describes in vitro and in vivo studies of the orthogonally radiolabelled complexes, inclusive of control experiments with [64Cu]CuATS~, the radiolabelled proligand and [64CU]CU2+ salts. In vitro cellular assays, as well as in vivo biodistribution studies including dynamic PET and SPECT were performed. Stability studies contrasting the in vitro and in vivo behaviour were carried out. The collective data suggest that the currently proposed redox trapping mechanism might not provide a full understanding of the factors governing biodistribution and tumour uptake. Chapter Six contains full experimental details for the work described in this thesis.

Oito complexos de manganês foram sintetizados com as tiossemicarbazonas ou semicarbazonas: salicilaldeído-4(N)-fenil-3-tiossemicarbazona (H2SAL-Phtsc), salicilaldeído-4(N)-metil-3-tiosemicarbazona (H2SAL-Metsc), salicilaldeído semicarbazona (H2SAL-Hsc), 2-hidroxiacetofenona semicarbazona (H2HAC-Hsc), salicilaldeído-4(N)-fenil-3-semicarbazona (H2SAL-Phsc) e 2-hidroxiacetofenona-4(N)-fenil-3-semicarbazona (H2HAC-Phsc). Estes agentes complexantes foram caracterizados por: ponto de fusão; RMN de 1H; análise elementar de C, H, N e S; difração de raios X em monocristal; espectroscopia de absorção no Infravermelho e UV-vis. Os complexos foram caracterizados pela combinação de analise elementar, condutividade molar, espectroscopia de absorção na região de infravermelho e UV-vis, susceptibilidade magnética, voltametria cíclica e/ou pulso diferencial e ressonância paramagnética de elétrons. Constantes de interação da albumina sérica humana com complexos [Mn(HSAL-Phtsc)2], [Mn(HHAC-Hsc)2] e [Mn(HSAL-Phsc)2] foram determinadas na faixa de 4,17-13,58 x 104 mol-1 s-1 L, indicando uma fraca interação com a HSA e podemos sugerir que a supressão da HSA não ocorre por uma colisão dinâmica, com valores de Kq na faixa de 2,08-6,79 x 1014 mol-1 s-1 L, superiores ao máximo possível para remoção dinâmica (2,0 x 1010 mol-1 s-1 L), indicando a existência de um mecanismo de extinção estática. Todos os complexos e ligantes foram testados contra linhagens celulares tumorais MDA-MB-231 (tumor de mama humano) e A549 (adenocarcinoma de pulmão humano). Entre os agentes complexantes, o que se destacou foi o salicilaldeído-4(N)-fenil-3-tiosemicarbazona, o qual apresentou IC50 de 8,77 ± 1,51 e 8,16 ± 1,45 mmol L-1, em MDA-MB-231 e A549, respectivamente, onde na linhagem A549 o IC50 é menor que a cisplatina. Os melhores valores de IC50 na linhagem MDA-MB-231 foram dos complexos de manganês com tiossemicarbazonas, complexos [Mn(SAL-Phtsc)2] e [Mn(HSAL-Phtsc)2] (5,89 ± 2,12 e 6,09 ± 1,18 &#181;mol L-1, respectivamente). E na linhagem A549 o complexo [Mn(HSAL-Phsc)2] obteve melhor valor de IC50 (12,23 ± 2,47 &#181;mol L-1). Os testes antimicobaterianos dos compostos mostraram que os complexos de manganês com tiossemicarbazonas, bem como as tiossemicarbazonas sintetizadas são potenciais agentes contra infecções micobacterianas, especificamente contra a Mycobacterium tuberculosis H37Rv. / Eight manganese complexes were synthesized with the thiosemicarbazones or semicarbazones: salicylaldehyde-4(N)-phenyl-3-thiosemicarbazone (H2SAL-Phtsc), salicylaldehyde-4(N)-methyl-3-thiosemicarbazone (H2SAL-Metsc), salicylaldehyde semicarbazone (H2SAL-Hsc), 2-hydroxyacetophenone semicarbazone (H2HAC-Hsc), salicylaldehyde-4(N)-phenyl-3-semicarbazone (H2SAL-Phsc) and 2-hydroxyacetophenone-4(N)-phenyl-3-semicarbazone (H2HAC-Phsc). These complexing agents were characterized by: melting point; 1H-NMR; Elemental analysis of C, H, N and S; X-ray diffraction on single crystal; absorption spectroscopy in Infrared and UV-vis. The complexes were characterized by the combination of elemental analysis, molar conductivity, infrared and UV-vis absorption spectroscopy, magnetic susceptibility, cyclic voltammetry and/or differential pulse and electron paramagnetic resonance. Human serum albumin interaction constants for complexes [Mn(HSAL-Phtsc)2], [Mn(HHAC-Hsc)2] and [Mn(HSAL-Phsc)2] were in the range of 4.17-13.58 x 104 mol-1 s-1 L, indicating a poor interaction with the HSA and we can suggest that the suppression of the HSA dose not occur by dynamic collision since the values of Kq in the range of 2.08-6.79 x 1014 mol-1 s-1 L are higher than the maximum possible for dynamic removal (2.0 x 1010 mol-1 s-1 L), indicating the existence of a static extinguishing mechanism. All complexes and ligands were tested against MDA-MB-231 (human breast tumor) and A549 (human lung adenocarcinoma) tumor cell lines. Among the complexing agents, salicylaldehyde-4(N)-phenyl-3-thiosemicarbazone showed IC50 of 8.77 ± 1.51 and 8.16 ± 1.45 ?mol L-1 in MDA- MB-231 and A549, respectively, where in line A549 the IC50 is lower than cisplatin. The best IC50 values in the MDA-MB-231 strain were from manganese complexes with thiosemicarbazones, complexes [Mn(SAL-Phtsc)2] and [Mn(HSAL-Phtsc)2] (5.89 ± 2.12 and 6.09 ± 1.18 &#181;mol L-1, respectively). And in the A549 line the complex [Mn(HSAL-Phsc)2] obtained a better value of IC50 (12.23 ± 2.47 &#181;mol L-1). The antimycobacterial tests of the compounds showed that the manganese complexes with thiosemicarbazones as well as the synthesized thiosemicarbazones are potential agents against mycobacterial infections, specifically against Mycobacterium tuberculosis H37Rv.