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Submitted by Onia Arantes Albuquerque (onia.ufg@gmail.com) on 2018-11-06T13:54:30Z No. of bitstreams: 2 Dissertação - Jhonny Willians de Oliveira Maciel - 2018.pdf: 3229754 bytes, checksum: 23b20bfd316d193ccfafa525bf314c79 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-11-07T09:38:43Z (GMT) No. of bitstreams: 2 Dissertação - Jhonny Willians de Oliveira Maciel - 2018.pdf: 3229754 bytes, checksum: 23b20bfd316d193ccfafa525bf314c79 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-11-07T09:38:43Z (GMT). No. of bitstreams: 2 Dissertação - Jhonny Willians de Oliveira Maciel - 2018.pdf: 3229754 bytes, checksum: 23b20bfd316d193ccfafa525bf314c79 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-09-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / New supramolecular systems based on metal complexes of formula [Fe(H2pcpa)2(H2O)2] (3), [Mn(Hpcpa)(H2O)3]n•1/2H2O (4), [Zn(Hpcpa)(H2O)3]n•1/2H2O (5) and [Cu2(Hpcpa)2(bipy)2]•5,6H2O (6) [H2pcpa- and Hpcpa2- ion derivative of EtH2pcpa (1) = N-(4-carboxyphenyl)oxamic ethyl ester] have been synthesized and describe in this work. The structure of 3 consists of discrete Fe(II) units, each metal ion is six-coordinate in a distorted octahedral environment with four oxamate-oxygens from a H2pcpa- ligand in the basal plane and two water molecules in the apical position. 4 and 5 is a neutral zigzag chain of Mn(II) and Zn(II) ions, respectively, bridged by Hpcpa2- ligands exhibiting the bidentate/monodentate coordination mode. Each metal ion is building a somewhat distorted octahedral surrounding. The distance between metals ions intrachain is 11.456 Å (4) and 11.325 Å (5). Complex 6 consists of a dimer in which the Cu(II) ions is found in a square-shaped pyramidal geometry connected by two Hpcpa2- and the 2,2'-bipyridine as a terminal ligand. / Foram obtidos novos sistemas supramoleculares baseados em compostos de coordenação com o ligante ácido N-(4-carboxifenil) oxâmico etil éster (EtH2pcpa/1) e os metais Fe(II), Mn(II), Cu(II) e Zn(II). As sínteses, caracterizações espectroscópicas e elucidação das estruturas cristalinas de quatro compostos inéditos de fórmula [Fe(H2pcpa)2(H2O)2] (3), [Mn(Hpcpa)(H2O)3]n•1/2H2O (4), [Zn(Hpcpa)(H2O)3]n•1/2H2O (5) e [Cu2(Hpcpa)2(bipy)2]•5,6H2O (6) foram descritas nesse trabalho. O complexo 3 formou monocristais de cor laranja amarronzada, cuja a estrutura consiste em um monômero de Fe(II). Cada íon de Fe(II) é hexacoordenado com esfera de coordenação composta de duas moléculas de água posicionadas em trans e quatro oxigênios-oxamato de dois ligante H2pcpa-. Os compostos 4 e 5 formaram monocristais transparentes incolores cujas estruturas cristalinas são formadas por cadeias em ziguezague neutras de íons Mn(II) e Zn(II), respectivamente. Cada íon metálico está hexacoordenado com as três moléculas de água posicionadas em Meridional, dois oxigênios-oxamato de um ligante Hpcpa2- e um oxigênio-carboxilato de um outro grupo do Hpcpa2-. A distância entre os metais intracadeia Mn...Mn no complexo 4 é de 11,456 Å e Zn...Zn no complexo 5 é de 11,325 Å. O complexo 6 formou monocristais azuis, a estrutura consiste em um dímero em que o íon de Cu(II) encontra-se penta coordenado em uma geometria piramidal de base quadrada com dois íons de Cu(II) ligados por dois ligantes Hpcpa2- e com o ligante 2,2'-bipiridina atuando como ligante terminal.

Thesis (Ph. D.)--Miami University, Dept. of Chemistry and Biochemistry, 2008. / Title from second page of PDF document. Includes bibliographical references.

No description available.

No description available.

Les travaux décrits dans ce manuscrit s’intéressent au contrôle du mouvement moléculaire. Après une introduction dédiée à l’état de l’art des machines moléculaires, le premier chapitre s’intéresse à la conception de tourniquets moléculaires à base de complexes porphyriniques de P(V). Le mouvement moléculaire a pu être contrôlé de manière réversible soit par l’utilisation des sites de coordination présents à la périphérie du système soit par des variations de pH. Le deuxième chapitre s’intéresse aux propriétés photophysiques des porphyrines de P(V) obtenues et plus particulièrement à leur capacité à générer de l’oxygène singulet avec une application potentielle en Thérapie Photodynamique (PDT).Le troisième chapitre concerne l’élaboration d’un complexe contenant deux porphyrines de Zn(II) dont le mouvement relatif a pu être bloqué réversiblement par l’utilisation des positions axiales des cations métalliques. / The manuscript focuses on molecular machines and the control of their movement. Two different devices have been designed, synthetized and characterized. Moreover, a series of new potential photosensitizer was obtained.The introduction gives a general overview on molecular machines, reported during the past 20 years. The first chapter describes the synthesis of molecular turnstiles based on P(V) porphyrins. The molecular motion was controlled reversibly using either coordination chemistry or by changing the pH. The second part is dedicated to the study of the photophysical properties of P(V) porphyrins and especially their capacity to generate singlet oxygen under irradiation., making them potential photosensitizers that can be use in Photodynamic Therapy (PDT) or as catalyst. The third chapter is devoted to the study of a molecular break based on a Zn (II) porphyrin dimer. The control of the movement was performed using the coordination of a bidentate ligand in the axial position of the metal cations.

Submitted by Fernanda Stuani Pereira null (ferstuani@hotmail.com) on 2016-06-22T22:22:49Z No. of bitstreams: 1 Tese-FERNANDA STUANI PEREIRA.pdf: 6105856 bytes, checksum: 653cf59956934017da496664aa74e886 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-06-24T17:11:14Z (GMT) No. of bitstreams: 1 pereira_fs_dr_prud.pdf: 6105856 bytes, checksum: 653cf59956934017da496664aa74e886 (MD5) / Made available in DSpace on 2016-06-24T17:11:14Z (GMT). No. of bitstreams: 1 pereira_fs_dr_prud.pdf: 6105856 bytes, checksum: 653cf59956934017da496664aa74e886 (MD5) Previous issue date: 2016-06-09 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente trabalho descreve modificações estruturais feitas na cadeia lateral do polímero quitosana mediante a N-alquilação com diferentes aldeídos aromáticos, a qual originam bases de Schiff como produtos intermediários, seguido de uma redução com cianoborohidreto de sódio (NaBH3CN). Subsequentemente, reações de acoplamento entre o produto sintetizado N-benzil quitosana e diferentes sais de diazônio foram realizadas para produzir uma nova classe de compostos poli-azóicos a partir deste polímero. Diferentes materiais foram sintetizados para investigar a influencia de diferentes substituintes na complexação de metais e futuros estudos de eficiência biológica. Pela técnica de ressonância magnética nuclear de próton em solução, o grau de substituição dos poli-azo-compostos foi de 46 a 66%. Os compostos foram caracterizados por FT-IR e RMN de 13C no estado sólido e RMN de 15N em solução, que confirmaram a síntese dos derivados poliméricos. Também foi realizado um estudo da interação destes materiais sintetizados com os íons metálicos Cu(II) e Zn(II). Para a caracterização dos complexos, utilizou-se as técnicas de titulação complexométrica, FAAS, MEV, EDS, difratometria de raios X, EPR e TG/DTG. Por titulação complexométrica e FAAS, a quitosana pura mostrou maior capacidade em complexar/adsorver os metais do que seus derivados. A capacidade de adsorver íons Cu(II) foi maior do que íons Zn(II) para todos os compostos. Por MEV e EDS, observou-se que além do cobre coordenado pelos sítios reativos dos materiais, o sal sulfato de cobre foi adsorvido pela superfície polimérica dos mesmos. Assim, foram realizadas reações de complexação utilizando o sal CuCl2.2H2O e os resultados mostraram que esse comportamento não ocorre para este sal. Para os complexos utilizando o sal sulfato de zinco, praticamente não se observa o sal adsorvido na superfície polimérica, devido à baixa capacidade de complexação por esse metal. A difratometria de raios X mostrou uma redução da cristalinidade dos complexos de cobre e zinco formados pela quitosana e o derivado Q1Benzil devido a maior capacidade desses materiais em quelar íons metálicos. Para os complexos de Cu(II) e Zn(II) formados a partir do composto Azo-Anisidina, o índice de cristalinidade aumenta, o que pode estar associado a formação de diferentes ligações de coordenação nesse composto. A formação dos complexos também foi confirmada por espectroscopia Raman. Os espectros de EPR dos complexos de Cu(II) formados a partir do sal CuCl2.2H2O mostram a presença de uma estrutura hiperfina bem resolvida, da mesma forma que foi observado para o complexo Quitosana-CuSO4, na qual a grande maioria dos centros de cobre são monoméricos e provavelmente ligados aos polímeros. As curvas de TG/DTG mostraram que os derivados poliméricos degradam a temperaturas menores que o polímero não modificado, e os complexos com sulfato de cobre apresentaram perfis TG/DTG diferentes dos complexos sintetizados a partir do sal cloreto de cobre. Por fim, tanto a quitosana quanto seus derivados Q1Benzil, Q2Benzil e Q2Benzil utilizando a quitosana de baixo peso molecular se mostraram efetivos na síntese de carbonatos através da captura e fixação de CO2 por estes materiais poliméricos. / The present work describes structural modifications in the side chain of the polymer chitosan by N-alkylation with different aromatic aldehydes, which originates Schiff base as an intermediate, followed by reduction with sodium cyanoborohydride (NaBH3CN). Subsequently, coupling reactions between the synthesized product N-benzyl chitosan and various diazonium salts were carried out to produce a new class of poly-azo compounds from this polymer. Different materials were synthesized to investigate the influence of different substituents on metal chelation and future studies of their biological efficience. From nuclear magnetic resonance technique, the degree of substitution of the poly-azo compounds was between 46 and 66%. The compounds were characterized by FT-IR, 13C NMR in solid state and 15N NMR in solution, which confirmed the synthesis of the polymeric derivatives. The interaction of the synthesized materials with the metal ions Cu(II) and Zn(II) was also studied. For the characterization of such metal complexes, the techniques complexometric titration, FAAS, SEM, EDS, X-ray diffraction, EPR and TG/DTG were employed in this work. By complexometric titration and FAAS, pure chitosan showed greater capacity for complex/adsorb metals than its derivatives. The capacity of adsorbing Cu(II) ions was greater than Zn(II) ions for all compounds. The synthesized complexes were studied by various spectroscopic techniques. By SEM and EDS, it was observed that in addition of copper coordination, copper sulphate salt was adsorbed by the polymer surface. Thus, complexation reactions were carried out using the salt CuCl2.2H2O and the results showed that this behavior does not occur for this salt. For complexes using zinc sulfate salt, hardly observes this salt adsorbed on the polymeric surface due to the low capacity for complexing this metal. The X-ray diffraction showed a reduction of the crystallinity of copper and zinc complexes formed by chitosan and Q1Benzil derivative due to the greater ability of these materials to chelate metal ions. For the complexes of Cu(II) and Zn(II) formed from Azo-Anisidine compound, the crystallinity index increases, which can be associated with formation of different coordination bonds with the compound. The formation of the complex was also confirmed by Raman spectroscopy. EPR spectra of Cu(II) formed from the CuCl2.2H2O salt showed the presence of well resolved hyperfine structure in the same way as it was observed for chitosan-CuSO4, in which the majority of copper centers are monomeric and probably bound to the polymer. The TG/DTG curves showed that polymeric derivatives are less stable than the unmodified polymer, and complexes with copper sulfate had TG/DTG curves different from the complexes synthesized from copper chloride salt. Finally, chitosan and the derivatives Q1Benzil , Q2Benzil and Q2Benzil from low molecular weight chitosan were effective in the synthesis of carbonates through the capture and sequestration of CO2 by these polymeric materials. / FAPESP: 2012/13901-3

Tese de mestrado integrado. Engenharia Química. Faculdade de Engenharia. Universidade do Porto. 2013

Zahlreiche Studien belegen, dass Maillard-Reaktionsprodukte (MRP) in vivo einen Einfluss auf den physiologischen Metallionenhaushalt haben können. Da bisher noch keine Korrelation zwischen dem Entstehen von definierten MRP und einem erhöhten Metallionenbindungsvermögen ermittelt werden konnte, war es das Ziel dieser Arbeit, die Komplexbildungseigenschaften der ausgewählten MRP Nε-Carboxymethyllysin, Isomaltol und Maltosin sowie deren Strukturanaloga Maltol, Deferipron, Mimosin und Pyridosin mit den physiologisch relevanten Metallionen Cu(II), Zn(II), Fe(III), Al(III) und Mn(II) zu untersuchen. Dazu wurden die MRP Nε-Carboxymethyllysin und Maltosin sowie die parallel untersuchten Substanzen Pyridosin, Maltosin-3-benzylether, Nα-Hippuryl- und Nα-Acetylmaltosin in ausreichender Menge und Reinheit synthetisiert. Dabei gelang es, für Maltosin und Pyridosin neue und effiziente Synthesewege zu entwickeln, bei welchen zum ersten Mal beide Substanzen gezielt aufgebaut wurden. Die Komplexbildungskonstanten der Liganden mit den Metallionen wurden pH-potentiometrisch bestimmt (I[KNO3] = 0,15 M; θ = 25 °C). Durch die Auswertung der Protonierungskonstanten der gebildeten Komplexe und das Vermessen geeigneter Derivate konnten für die untersuchten Komplexe zusätzlich die Koordinationsstellen der Liganden aufgeklärt werden. Die Untersuchungen zu den Komplexbildungseigenschaften bestätigten erstmals die Vermutung, dass MRP in der Lage sind, Metallionen zu binden. Dabei wurde weiterhin ermittelt, dass die Bindung von Cu(II) durch Nε-Carboxymethyllysin und von Fe(III), Al(III) und Cu(II) durch Maltosin durchaus von physiologischer Relevanz sind. Die Bedeutung der Ergebnisse wurde qualitativ durch Versuche mit Maltosin-derivatisiertem Rinderserumalbumin unterstrichen. Als besonderes Ergebnis der Arbeit ist herauszustellen, dass das MRP Maltosin und die Verbindung Pyridosin deutlich stabilere Komplexe mit Fe(III) bilden als das zur Fe(III)-Chelattherapie eingesetzte Medikament Deferipron. Diese festgestellte Eigenschaft bietet interessante Perspektiven für zukünftige Studien zur möglichen Anwendung von z. B. Maltosin als Pharmakon. / Several studies show that Maillard reaction products (MRP) may influence the physiological metal ion balance. But none of these studies prove a correlation between the formation of defined MRP and an enhanced metal ion binding. Therefore it was the aim of this work to investigate the complex formation characteristics of the selected MRP Nε-carboxymethyllysine, isomaltol and maltosine as well as the structural analogues maltol, deferiprone, mimosine and pyridosine with the physiological relevant metal ions Cu(II), Zn(II), Fe(III), Al(III) and Mn(II). For that purpose the MRP Nε-carboxymethyllysine and maltosine plus the parallel analysed substances pyridosine, maltosine-3-benzylether, Nα-hippuryl- and Nα-acetylmaltosine were synthesised. Thereby new and efficient syntheses for maltosine and pyridosine were developed. The stability constants of the ligands with the metal ions were determined by pH-potentiometry (I(KNO3) = 0,15 M; θ = 25 °C). Furthermore the donor atoms within the formed complexes were determined by the evaluation of the protonation constants of the formed complexes and by the analysis of adequate derivatives. The studies to the complex formation characteristics confirm for the first time the assumption, that MRP are able to form stable complexes with metal ions. Withal it was ascertained that the coordination of Cu(II) by Nε-carboxymethyllysine and of Fe(III), Al(III) and Cu(II) by maltosine may be of physiological relevance. The significance of the results was pointed out by experiments with maltosine derivatised bovine serum albumine. The fact that the MRP maltosine and the compound pyridosine form more stable complexes with Fe(III) as the medicament for the Fe(III) chelate therapy deferiprone is a particular result of this work. This property affords interesting perspectives for future studies about a possible appliance of e.g. maltosine as pharmaceutical.

As a human fungal pathogen, Candida albicans can cause a wide variety of disease conditions ranging from superficial to systemic infections. Many of these infections are caused by an inherent ability of the pathogen to form biofilms on medical devices resulting in high mortality. Biofilms formed by C. albicans are a complex consortium of yeast and hyphal cells embedded in an extracellular matrix and are regulated by a network of transcription factors. Here, I report the role of a novel Zn(II)2-Cys6 binuclear cluster transcription factor, ZCF32, in the regulation of biofilm formation. Global transcriptome analysis reveals that biofilm development is the most altered pathway in the zcf32 null mutant. To delineate the functional correlation between ZCF32 and biofilm development, the set of genes directly regulated by Zcf32 were determined. The data suggest that Zcf32 regulates biofilm formation by repressing the expression of adhesins, chitinases and a significant number of other GPI-anchored proteins. The data presented here establish that there is the lesser recruitment of Zcf32 on the promoters of biofilm genes in biofilm condition compared to the planktonic mode of growth. Thus, the transcription factor ZCF32 negatively regulates biofilm development in C. albicans. Candida albicans, carries an expanded family of Zn(II)2Cys6 transcription factors. A CTG clade-specific protein Zcf32 and its closely related protein Upc2, a well-conserved protein across the various fungal species, belong to this family of proteins. Unlike Upc2, Zcf32 is poorly studied in C. albicans. Here, I examined roles played by these two related transcription factors in biofilm development and virulence of C. albicans. The data show that the null mutants of each of ZCF32 or UPC2 form better biofilms than the wild-type suggesting that both of them negatively regulate the biofilm development. While acting as negative regulators of biofilm formation, these two transcription factors target a different set of biofilm genes. A mouse model of candidiasis reveals that zcf32/zcf32 was hypervirulent while upc2/upc2 shows compromised virulence compared to the wild-type. Notably, the absence of Zcf32 enhances detrimental inflammation brought about by TNFα, IFNβ, and IFNγ. upc2/upc2 failed to generate a similar feedback, instead demonstrated an elevated anti-inflammatory (IL4 and IL10) host response. Taking together, the data exhibit how a recently evolved transcription factor Zcf32 retained functional resemblance with a more ubiquitous member Upc2 but also functionally diverged from the latter in the regulation of virulence of the pathogen.