abstract: The field of Ionic Liquid (IL) research has received considerable attention during the past decade. Unique physicochemical properties of these low melting salts have made them very promising for applications in a many areas of science and technology such as electrolyte research, green chemistry and electrodeposition. One of the most important parameters dictating their physicochemical behavior is the basicity of their anion. Using four sets of Protic Ionic Liquids (PILs) and spectroscopic characterization of them, a qualitative order for anion basicity of ILs is obtained. Protic Ionic Liquids are made by proton transfer form a Brønsted acid to a base. The extent of this transfer is determined by the free energy change of the proton transfer process. For the cases with large enough free energy change during the process, the result is a fully ionic material whereas if the proton transfer is not complete, a mixture of ions, neutral molecules and aggregates is resulted. NMR and IR spectroscopies along with electrochemical and mechanical characterization of four sets of PILs are used to study the degree of ionicity. / Dissertation/Thesis / Doctoral Dissertation Chemistry 2016

abstract: Viral protein U (Vpu) is a type-III integral membrane protein encoded by the Human Immunodeficiency Virus-1 (HIV- 1). It is expressed in infected host cells and plays vital roles in down-regulation of CD4 receptors in T cells and also in the budding of virions. But, there remain key structure/function questions regarding the mechanisms by which the Vpu protein contributes to HIV-1 pathogenesis and thus, it makes for an attractive target to study the structural attributes of this protein by elucidating a structural model with X-ray crystallography. This study describes a multi-pronged approach of heterologous over-expression of Vpu. The strategies of purification and biophysical/ biochemical characterization of the different versions of the protein to evaluate their potential for crystallization are also detailed. Furthermore, various strategies employed for the crystallization of Vpu by both in surfo and in cubo techniques, and the challenges faced towards the structural studies of this membrane protein by characterization with solution Nuclear magnetic resonance (NMR) spectroscopy are also described. / Dissertation/Thesis / Doctoral Dissertation Molecular and Cellular Biology 2016

Neste trabalho, descrevemos o desenvolvimento do equipamento e o software necessários à implementação da técnica de obtenção de imagens por RMN. Nossos principais objetivos foram a construção de um sistema de controle e aquisição de dados que permitisse operar um espectrômetro de Fourier de RMN pulsada como um tomógrafo de RMN; por outro lado, visamos a construção de um espectrômetro que tivesse seus parâmetros facilmente reconfiguráveis pelo sistema de controle. O resultado foi um sofisticado equipamento que permite, além do proposto, trabalhar com técnicas de espectroscopia de alta resolução e espectroscopia em sólidos. Uma grande ênfase foi dada ao entendimento das técnicas De reconstrução de imagens, desde as convencionais até aquelas que constituem atualmente a fronteira de pesquisa nessa área. Os resultados obtidos com o sistema descrito são considerados bons, comparáveis aos das unidades construídas por empresas que operam comercialmente nessa área, em cooperação com centros localizados em universidades no exterior, pouco devendo a equipamentos similares (protótipos) desenvolvidos naqueles centros. / We describe in this work the development of hardware and software necessary to implement the Magnetic Resonance Imaging (MRI) techniques. Our major subjects were the construction of an acquisition and control system which allowed the operation of a pulsed Fourier NMR spectrometer as a NMR Tomograph; further we oriented the developing of a NMR spectrometer whose parameters could be easily reconfigured by the controlling system. As a result we obtained a sophisticated equipment which allows, more than the proposed, working with high resolution spectroscopic techniques and spectroscopy in solids. Since the basic techniques employed in NMR and CT Tomographs are well known, a great emphasis was also given on the understanding of the image reconstruction techniques that constitutes today the frontier of research in this area. The results obtained with the system described here are considered good, comparable to the results from commercial units developed in cooperation with imaging groups located in universities abroad.

Orientadores: Nelci Fenalti Hoerhr, Roberto Rittner Neto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-06T21:30:04Z (GMT). No. of bitstreams: 1 Sega_EstelaMunhoz_M.pdf: 1403353 bytes, checksum: 0aec5b888298032d359cc1b3cf0905b6 (MD5) Previous issue date: 2006 / Resumo: Esse estudo analisou as propriedades toxicológicas de novos compostos organofosforados. Foram realizados experimentos para avaliar a atividade anticolinesterásica desses organofosforados, in vitro, no sangue total através do método de Ellman modificado. Para determinar a sua citotoxicidade foram utilizadas células PC 12, com as quais avaliamos a viabilidade celular após contato com os organofosforados e determinamos a IC 50, encontrando valores muito diferentes para os diversos organofosforados estudados. Estudos de toxicidade aguda in vivo foram realizados com camundongos, através da metodologia recomendada pela OECD nos quais determinamos a DL50 para três dos organofosforados estudados, sendo que um apresentou toxidade moderada. Foram analisados os efeitos dos solventes nas constantes de acoplamento JHH, JHH, JNC e 2Jnc em espectros de RMN de LH e 13C do cloreto de acetilcolina. Os valores das constantes de acoplamento em solventes de diferentes constantes dielétricas (s) não sofreram variações, indicando uma ausência de efeitos de solvente no equilíbrio conformacional do cloreto de acetilcolina (ACh). As constantes de acoplamento mostram que o sistema OCH2CH2N+ tem uma conformação gaúche (sinclinal). O Jnh e Jkc são observados na maioria dos solventes, mas não em solventes clorados e não são dependentes da viscosidade do solvente, esse comportamento foi explicado usando dados de medidas de Ti. Os valores dos coeficientes de difusão de RMN mostraram que a ACh tem uma grande tendência de se agregar quando dissolvida em solventes clorados, fato que pode explicar as diferenças observadas em valores de T1 para o 14N / Abstract: This study analyzed the properties of the news organophosphorus. Experiments had been carried through to evaluate the inhibition of acetylcholinesterase of these organophosphorus, in vitro, through the modified EUman's method. In order to determine its cytotoxicity cells PC 12 had been used, with which we evaluate the cellular viability after contact with the organophosphorus and determined the IC50, different values were found for the diverse organophosphorus. Studies of acute toxicity had been carried through with mice, following the methodology recommended by the OECD in which determine the DL50 for three of the organophosphorus studied, being that one presented moderate toxicity. Coupling constants values ( Jhh and Jnc) obtained from the 'H and 13 C NMR spectra of acetylcholine chloride (ACh) in several solvents with a wide range of dielectric constants (e) are remarkably invariant, indicating an absence of solvent effects in the conformational equilibrium of this compound. Those values show that the OCH2CH2N+ system occurs in a synclinal conformation. The Jnh and Jnc are observable in most solvents, but not in chlorine-containing solvents and are not dependent on solvent viscosity. This behavior was explained using data from Ti measurements. The measurement of NMR diffusion coefficients show that ACh has a greater tendency to aggregate when dissolved in chlorinated solvents, a fact that could explain the observed differences in 14N T1 / Mestrado / Patologia Clinica / Mestre em Ciências Médicas

A técnica de dupla ressonância unidimensional para alta resolução em líquidos constitui o objetivo deste trabalho. Para isso construiu-se uma sonda de dupla ressonância, apropriada para experiências heteronucleares do tipo 13C-{1H}. Empregam-se algumas sequências de pulsos para permitir as medidas do EON e do desacoplamento nuclear entre 1H e 13C. Emprega-se o EON com a finalidade de obter um aumento na intensidade do sinal de RMN do 13C; emprega-se o desacoplamento para eliminar a estrutura fina que surge devido ao acoplamento nuclear entre 1H e 13C. Inclui-se uma breve revisão sobre a teoria com a fmalidade de unificar o tratamento desta com as aplicações. As técnicas experimentais são discutidas e alguns espectros são mostrados para ilustrar os principais resultados / The one dimensional double resonance technique for high resolition in liquids is the main purpose of this work. For this we have built a double resonance probe, suitable for heteronuclear 13C-{1H} experiment. Some pulse sequences are employed to allow the NOE and decoupling between 1H e 13C to be measured. The NOE is employed in order to obtain a three-fold enhancement of the 13C NMR signal; decoupling is employed to eliminate the fme structW\'e arising from spin coupling between 1H e 13C. A short review about theory is included to provide unified treatment with applications. The experimental techniques are discussed and some spectra are shown to illustrate the main results.

No description available.

Abstract The first part of this work consisted of a study of the coordination chemistry of aromatic (P,S) and (P,O) heterodonor phosphanes with Cr(CO) 6 , Mo(CO) 6 and W(CO) 6 . The (P,S) donor ligands having one or two o -thiomethoxyphenyl groups, preferred bidentate coordination mode, while the (P,O) donor ligands, having one, two or three o -methoxyphenyls, formed monodentate phosphorus bound complexes. Steric and electronic parameters affecting the coordination chemistry of the phosphanes are discussed for the monodentate complexes. In the second part, triphenylphosphane and 2- and 4-pyridyldiphenylphosphane substituted tungsten tetracarbonyl derivatives was prepared, and attractive intramolecular interactions between the phosphane ligands were studied for both the neutral and the protonated complexes. Hydrogen bonding, π -stacking and cation-π bonding interactions were established, and observed to influence the cis/trans isomerism of the complexes. Cis/trans isomerism could be tuned by protonation, and deprotonation of the pyridyldiphenylphosphane derivatives. All the complexes were characterised by 1 H, 13 C-{ 1 H} and 31 P-{ 1 H} NMR spectroscopy, X-ray crystallography, IR spectroscopy, and either elemental analysis or mass spectroscopy.

Les protéines prions sont associées à une classe de maladies neurodégénératives, dont l'encéphalopathie spongiforme transmissible (EST) est la mieux connue. La protéine prion Sup35p représente un tel modèle car elle est non associée à une maladie. Sup35p se compose de trois domaines : un domaine N-terminal qui est responsable de la formation de prion, d'un domaine de milieu (M) qui affiche un degré élevé de flexibilité, et un domaine C-terminal fonctionnel et globulaire. Le fragment Sup35pNM est souvent utilisé comme modèle pour documenter l'assemblage et les propriétés infectieuses de Sup35p. Les études de Sup35p et Sup35pNM par RMN du solide ont révélé d'étonnantes différences structurelles entre les deux cœurs amyloïdes de Sup35p et Sup35pNM. Nos résultats sur Sup35p apportent un nouvel éclairage sur le monde étonnamment diversifié des prions où la variabilité conformationnelle joue un rôle énorme et perturbant. Ils reflètent l'image émergente que les prions sont des unités structurelles complexes. En effet, même s'il affiche une structure très définie, un domaine donné peut adopter des conformations différentes selon les circonstances (en isolation, dans le contexte d'un fragment ou la protéine entière) ou de l'environnement (conditions de tampon, présence de chaperonnes). Nos résultats donnent une explication au niveau moléculaire pour la contractante propension à l'assemblage et l'infectiosité de Sup35pNM et Sup35p, et soulignent l'importance primordiale d'une caractérisation structurale au niveau moléculaire des agrégats utilisés dans des études fonctionnelles / Prion proteins are associated with a class of neurodegenerative diseases, including transmissible spongiform encephalopathy (TSE) which is the best known. The prion protein Sup35p displays a model system because it is not associated with disease. Sup35p consists of three domains: an N-terminal domain which is responsible for the prion formation, a middle domain (M) that displays a high degree of flexibility, and a functional C-terminal domain. Sup35pNM the fragment is often used as a model to document for the assembly and infectious properties of Sup35p. Solid-state NMR studies of Sup35p and Sup35pNM fibrils showed amazing structural differences between the two amyloid cores. Our results shed new light on the surprisingly diverse world of prions where conformational variability plays a huge role. They reflect the emerging picture that prions are complex structural units. Even if it displays a very defined structure, a given field may adopt different conformations depending on the circumstances (in isolation, in the context of the whole protein or fragment) or the environment (buffer conditions, presence of chaperones). Our results provide an explanation at the molecular level for the contrasting propensity assembly and infectivity Sup35pNM and Sup35p, and emphasize the central importance of a structural characterization at the molecular level

Developments in Multivariate DOSY processing and Pure Shift NMR, authored by Adam Colbourne and submitted for the degree of Doctor of Philosophy in the Faculty of Engineering and Physical Sciences at the University of Manchester, 26th February 2014. The theme of this thesis is resolution; the separation of overlapping, entangled information in NMR spectroscopy data. The ability to resolve the features of a dataset is important because it greatly simplifies, or even makes possible, the interpretation of those features to yield information. Here, methods developed to increase resolving power in two different areas of NMR spectroscopy are described; these areas are so-called 'pure shift' or δ-resolved NMR and diffusion-ordered spectroscopy (DOSY). Pure shift NMR aims to reduce the overlap of the signals present in an NMR spectrum by collapsing the multiplet structure caused by spin-spin coupling. There are a variety of methods for achieving this, each of which has its pros and cons. A homo-nuclear decoupling scheme originated by K. Zangger and H. Sterk is implemented in its most recent form to decouple the F1 and F2 dimensions of the 2D NOESY experiment individually. The application of covariance processing to allow the removal of all the multiplet structure from data produced by these singly decoupled experiments is demonstrated and the results discussed. Full experimental homo-nuclear decoupling of 2D NMR is discussed and demonstrated with the TOCSY experiment using a combination of Bax's constant time decoupling scheme in F1 and Zangger-Sterk decoupling in F2. DOSY is strictly a catch-all term for the data processing applied to pulsed field gradient NMR data to extract information on the diffusion of chemical species, but is widely accepted as referring to the combination of the two. Applied to mixtures, DOSY is a powerful tool that can allow the separation of the spectra of the mixture components; this greatly simplifies the process of interpreting mixture NMR data. However, DOSY processing struggles where signals from different, but similarly diffusing chemical species overlap; one is faced with the problem of separating similar, overlapping exponentials in noisy data. Standard DOSY processing schemes can be described as univariate or multivariate with respect to the way in which they handle DOSY data; the former analyses the data a single frequency at a time, the latter tries to untangle the whole dataset at once. Multivariate processing schemes are better suited to resolving overlap in DOSY data, because they use all of the information available, the counter point being that too much information causes them to break down. SCORE is one such algorithm. Research into constraining and augmenting SCORE is presented, leading into a discussion of the potential application of prior knowledge of the DOSY dataset. While exploring the application of prior knowledge, it was realised that the differences between the spectra extracted by SCORE could be used to separate mixture components in a general manner. The presented OUTSCORE algorithm uses information from both the spectra and diffusion dimensions of DOSY data to separate components almost an order of magnitude more similarly diffusing than was previously possible. Finally, a hybrid processing scheme termed LOCODOSY is reported, that breaks a dataset down into smaller sections for individual multivariate analysis before recombination of the results; circumventing the problem of having too much or too little data in any one analysis. The LOCODOSY processing scheme is demonstrated on both the SCORE and OUTSCORE algorithms.

In the 1960s, Rosenberg and his colleagues confirmed the anti-cancer activity of cisplatin. Although cisplatin was capable of killing testicular cancer cells there were also serious side effects. It was necessary to find alternate ways of overcoming side effects, and soon many researchers have discovered novel platinum compounds that show similar reactivity. Recently, replacing one chloride group to a heterocyclic amine group showed significant cytotoxicity with a different binding activity than cisplatin. Previously in our lab, [Pt(Me5dien)(NO3)]+ and [Pt(Et2dien)Cl]+ have been synthesized and reacted with NAcetyl- L-methionine (N-AcMet) and Guanosine 5’-monophosphate (5’-GMP) showed unusual reactivity. Unlike most previously studied platinum triamine compounds, Me5dien compound was reacting faster with 5’-GMP than N-AcMet, due to the bulkiness of the triamine ligand. When both N-AcMet and 5’-GMP were reacted with Et2dien, 5’- GMP displaced one amine group of the triamine ligand and replaced that spot to form a bis-adducts, when the pH was kept below 4. Here a new novel platinum compound has been synthesized with a seven-membered chelate ring triamine ligand, Chloro[2-(4- methyl-1,4-diazepan-1-yl)ethanamine]platinum(II) chloride ([Pt(L)Cl]+). The unusual binding activity of [Pt(L)Cl]+ showed a unique pair of products under 1H NMR, 195Pt NMR and LC/MS spectrometry.