The use of two different chelating redox active ligands, 2,6-bis(6-methyl-1,2,4,5-3-yl) pyridine (BTZP) and 2,6-bis-(5,6-dialkyl-1,2,4-triazin-3-yl)-pyridine (BTP) in heterometallic first row and second row transition metal chemistry has yielded two new families of redox active metal complexes. These complexes were found to exhibit interesting electrochemical and magnetic properties. In this thesis, Chapter 1 lays the foundation for the research presented within. This section covers the fundamentals of the ligand design, ligand synthesis and related coordination chemistry literature review. Chapters 2 and 3 report the results of the current thesis. In Chapter 2, the synthesis and characterization of a family of discrete molecules and supramolecular arrangements, employing the ligand BTZP, is presented. All of the complexes presented in Chapter 2 are successfully synthesized and characterized with electrochemical and magnetic studies. According to the electrochemical data, it is found that the classic “terpy-like” complexes with [Co(BTZP) 2]2+ formula fosters more stability in the redox process. In Chapter 3, a family of transition metal complexes with [M(BTP) 2]2+ (M=Fe or Co) inorganic cores were obtained through the employment of the ligand BTP with various anions. In addition, dimeric molecules with [CoX4(BTP)2] formula were also obtained by solvothermal synthesis. The complexes were also electrochemically characterized, with all the complexes capable of being reduced, while only [CoII(BTP)2] (ClO4)2 showed reversible redox process. Similar with BTZP, the series of BTP based complexes are also characterized through magnetic measurement. Only cobalt-based BTP complexes are paramagnetic, with [CoII(BTP)2]2+ being spin crossover active when BF4- and ClO4- are present. However, the presence of NCS- and halides lead to either antiferromagnetic interactions and ferromagnetic interactions dominating at different temperature regimes.

Os efeitos do balanço cátion-aniônico da dieta (BCAD) na degradabilidade ruminal da MS e PB do farelo de soja, degradabilidade ruminal da MS e amido do fubá de milho, foram estudados em dois experimentos com diferentes proporções de volumoso:concentrado (experimento 1 - 60:40; experimento 2 - 40:60), em 12 bezerros Holandeses (peso médio de 91,55kg e de 117,62kg respectivamente), portadores de cânulas ruminais, realizados no Campus Administrativo de Pirassununga/SP, na FZEA/USP. Os períodos experimentais foram de 35 dias, sendo 14 dias de adaptação dos animais às gaiolas e às dietas e 21 dias de colheita de dados, com 15 dias de descanso. O delineamento foi o inteiramente casualizado, com três tratamentos e quatro repetições em ambos os experimentos. Para a manipulação do BCAD, foram adicionados sulfato de amônio e bicarbonato de sódio, obtendo-se os seguintes tratamentos no experimento 1: -123, +218 e +341 mEq/kg MS; e no experimento 2: -127, +207 e +397 mEq/kg MS. Utilizou-se silagem de milho como fonte de volumoso. Os níveis de BCAD influenciaram as degradabilidades ruminais da MS e PB do farelo de soja com a proporção de volumoso:concentrado de 60:40 (P<0,10). As degradabilidades ruminais da MS e amido do fubá de milho com a proporção volumoso:concentrado de 60:40, não foram afetadas pelos níveis de BCAD (P>0,10), assim como as degradabilidades ruminais da MS e PB do farelo de soja, MS e amido do fubá de milho com a proporção volumoso:concentrado de 40:60 (P>0,10). / The DCAB effects on dry matter (DM) and crude protein (CP) degradability of soybean meal and DCAB effects on DM and corn meal degradability were investigated in two trials with different rate of roughage:concentrate (experiment 1: 60:40, experiment 2: 40:60). Twelve Holstein calves with ruminal cannula were used in each experiment (91,55 kg and 117,62 kg of mean weight, respectively). Both experiments were conducted at FZEA/USP, Pirassununga/SP. The experimental periods were constituted by 35 days (14 days adaptation and 21 days data collection) with 15 days of interval. It was used completely design, with three treatments and four repetitions. For DCAB manipulation were added ammonium sulfate and sodium bicarbonate in order to achieve the following values: experiment 1: -123, +218, +341 mEq/kg DM, experiment 2: -127, +207, +397 mEq/kg DM. The diet was based on corn silage as forage. The DCAB ratios affected DM and soybean meal CP degradabilities when 60:40 roughage:concentrate ratio were used (P<0,10). DM and corn meal degradabilities were not affected by DCAB ratios (P>0,10), as well as DM and soybean meal CP degradabilities when 40:60 roughage:concentrate ratio were used P<0,10).

O efeito do balanço cátion-aniônico da dieta (BCAD) no desempenho, balanço macromineral (cálcio, fósforo, sódio e potássio), na fermentação ruminal , pH urinário e na concentração sérica de cálcio, foi estudado utilizando-se 25 ovinos machos, da raça Santa Inês, por um período de 75 dias. O delineamento experimental foi em blocos ao acaso, com cinco tratamentos. Para a manipulação do BCAD foram adicionados sulfato de amônio e bicarbonato de sódio, obtendo-se os seguintes tratamentos: -160, -40, 140, 250 e 500 mEq/kg MS. O aumento do BCAD resultou em aumento da IMS, aumento em ganhos diários e eficiência alimentar (P<0,05). O pH ruminal, pH urinário e o volume urinário aumentaram com aumento do BCAD (P<0,05). O perfil de ácidos graxos ruminais não foi afetado pelo BCAD. O BCAD influenciou o metabolismo macromineral principalmente o de cálcio, com a diminução do BCAD o cálcio sérico aumentou. Dietas aniônicas aumentaram a excreção urinária de cálcio, entretanto a retenção não foi afetada. / The dietary cation-anion balance (DCAB) effect in performance, macromineral (calcium, phosphorus and sodium) balance, urinary pH and calcium serum concentration, was studied in 25 males sheeps, from Santa Ines breed, during 75 days. The design used was randomized complete blocks, with five treatments. For DCAB manipulation were added ammonium sulfate and sodium bicarbonate in order to achieve the values: -160, -40, 140, 250 e 500 meq/kg DM. Increasing the DCAB resulted in higher DMI, daily gains and feed efficiency (P<0,05). Rumen pH, urine pH and urine volume increased as DCAB increased (p<0,05). Ruminal VFA profile was not affected by DCAB. The DCAB affected the calcium metabolism, decresing the DCAB the serum calcium increased. Dietary anionic increased urinary excretion of calcium, however calcium retention was not effect.

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Foram utilizadas 8 vacas Holandesas em lactação, distribuídas em um quadrado latino (4x4), replicado, conduzidos durante o verão, por um período de 72 dias. O objetivo desse trabalho foi estudar quatro níveis de dietas catiônicas, sobre a IMS, produção, composição e propriedades físico-químicas do leite, pH urinário, temperatura corporal e parâmetros ácido-base do sangue, em vacas após o pico de lactação. Para a manipulação do BCAD, foram adicionadas diferentes concentrações de bicarbonato de sódio nas dietas, obtendo-se os seguintes tratamentos: +150, +250, +400 e +500mEq/kg MS. A temperatura corporal das vacas não foi afetada pelo balanço cátion-aniônico da dieta. O bicarbonato, o pH, o CO2 total e a pCO2 do sangue aumentaram linearmente com o aumento do BCAD. A concentração de cálcio no sangue apresentou resposta quadrática, com maior valor para o menor BCAD. As concentrações de sódio e potássio do sangue não foram modificadas significativamente pelo BCAD e a concentração de cloro diminuiu linearmente com o aumento do BCAD. O aumento do BCAD resultou em aumento da ingestão de matéria seca e produção de leite. Não houve diferença significativa para as variáveis: porcentagem de gordura, densidade e índice crioscópico, do leite. O pH do leite aumentou linearmente e a acidez apresentou resposta cúbica, com o aumento do BCAD. Conclui-se que a manipulação do BCAD afeta o equilíbrio ácido-base das vacas, mesmo dentro de variação positiva. Devido ao aumento da IMS e da produção de leite, verificou-se efeito benéfico do uso de dietas catiônicas, para vacas após o pico de lactação. / Eight lactating Holsteins cows were distributed in 4 x 4 replicated Latin square, during the summer, for a period of 72 days. The objective of this research was to study the effect of four cationic diets levels, on the dry matter intake, milk production, composition, and physico-chemical parameters, urinary pH, body temperature and blood acid-base parameters, in cows, after the lactation peak. For DCAB manipulation were added different concentrations of sodium bicarbonate in the diets and the following treatments were obtainned: +150, +250, +400 e +500mEq/kg DM. The cows body temperature was not affected by dietary cation-anion balance. Blood bicarbonate, pH, total CO2 and pCO2 increased linearly with the increase of dietary CAB. Calcium concentration in the blood decreased quadratically with dietary CAB increased. Sodium and potassium concentration in the blood were not modified significantly with the DCAB and concentration of chloride decreased linearly with increase of DCAB. Increasing BCAD resulted in higher DM intake and milk yield. The diets did not affect milk fat percentage, density and crioscopic index. Milk pH increased linearly and acidity decreased cubically with the increase of dietary CAB. It was concluded that DCAB manipulation affected the acid-base status of cows, even inside of positive variation. Due to the increase of DM intake and milk yield, it was verified a beneficial effect of the cationic diets for cows after the lactation peak.

O Brasil possui uma imensa diversidade biológica, na qual muitos compostos bioativos podem ser encontrados e utilizados em beneficio à sociedade. No entanto, processos de degradação do ambiente e introdução de espécies exóticas têm contribuído ao conhecimento e uso limitadosde muitas plantas nativas, sendopequena a quantidade de estudos sobre sua composição química e potencial biológico. A prevenção de doenças crônicas constantemente vem sendo associada à atividade antioxidante de metabólitos secundários dos vegetais, principalmente os fenólicos. Assim, o objetivo deste trabalho foi avaliar a atividade antioxidante e composição fenólica de cinco espécies frutíferas nativas do Brasil (G. brasiliensis, E. leitonii, E. involucrata, E. brasiliensis e E. myrcianthes). Os métodos capacidade de redução do Folin-Ciocalteau, autoxidação do sistema ?-caroteno/ácido linoleico, capacidade de absorção de radicais oxigênio (ORAC), sequestro dos radicais livres DPPH e ânion superóxido foram aplicados na determinação da atividade antioxidante dos extratos etanólicos de folha, casca, semente e polpa das espécies selecionadas. As amostras demonstraram significativa atividade antioxidante e, em alguns casos, superior as frutas comumente consumidas pela população brasileira. Em geral, folhas apresentaram as maiores atividades, mas o destaque foi a semente de E. leitonii que exibiu os melhores resultados em quatro dos cinco métodos utilizados: 120,67 mg AG.g-1 na redução do reagente Folin; 7,08 Gmol Trolox.g-1 no ?-caroteno; EC50 de 0,26 mg.mL-1 e 0,07 mg.mL-1 no sequestro do ânion superóxido e DPPH, respectivamente; 514,75 Gmol Trolox.g-1 no ORAC para o qual a folha de E. involucrata obteve o maior valor (1393,3 Gmol Trolox.g-1). Os extratos das espécies nativas também demonstram efeito antioxidante contra radicais de relevância biológica, como peroxila e superóxido. Por meio de CG-EM e CLAE acoplado a arranjo de fotodiodos, os principais compostos fenólicos encontrados nos extratos vegetais foram catequina, epicatequina e ácido gálico. Este trabalho demonstrou o grande potencial antioxidante das frutíferas nativas brasileiras, evidenciando assim possível efeito positivo em sistemas biológicos. / Brazil has a great biodiversity, in which many bioactive compounds can be found and used to benefit the society. However, environmental degradation processes and introduction of exotic species have contributed to limited use and knowledge of many native plants, reflecting in few studies about chemical composition and biological potential. The prevention of chronic diseases has been constantly associated with the antioxidant activity of plants secondary metabolites, mainly the phenolics. The objective of this study was to evaluate the antioxidant activity and the phenolic composition of five Brazilian native fruitful species (G. brasiliensis, E. leitonii, E. involucrata, E. brasiliensis e E. myrcianthes). The methods of Folin-Ciocalteau reducing capacity, co-oxidation of ?-carotene/linoleic acid system, oxygen radical absorbance capacity (ORAC), DPPH and superoxide free radical scavenging were used to determine the antioxidant activity of ethanolic extracts of leaf, peel, seed and pulp of the selected species. The samples showed significant antioxidant activity and, in some cases, it was superior to fruits commonly consumed by Brazilian population. In general, leaves presented the highest activities, but the seed of E. Leitonii stood out exhibiting the best results in four of the five methods: 120.67 mg GA.g-1 in the Folin reducing; 7.08 Gmol Trolox.g-1 in the ?-carotene; EC50 of 0.26 mg.mL-1 and 0.07 mg.mL-1 in the superoxide and DPPH scavenging, respectively; 514.75 Gmol Trolox.g-1 in the ORAC, for which the E. Involucrata leaf had the highest value (1393.3 GmolTrolox.g-1). The extracts of native species also demonstrate antioxidant effect against radicals of biological relevance, such as peroxyl and superoxide. By GC-MS and HPLC coupled to a photodiode array, the major phenolic compounds found in the plant extracts were catechin, epicatechin and gallic acid. In this study, Brazilian native fruitful presented high antioxidant potential, showing a possible positive effect on biological systems.

Tensides rank among the surfactants with ability to reduce surface tension. This ability is used to remove impurities. Surfactants can be divided into four basic groups: anionic, cationic, nonionic and zwitterionic. Anionic surfactants belong to the most widespread surfactants in the Czech Republic today. They get into sewage waters from various cleansing and washing agents which are used both in households and industry. So this diploma thesis deals with their assessment by application of capillary electrophoresis.

Protein folding studies have provided important insights about the key role of non-covalent interactions in protein structure and conformational stability. Some of these interactions include salt bridges, cation-π, and anion-Ï€ interactions. Understanding these interactions is crucial to developing methods for predicting protein secondary, tertiary, quaternary structure from primary sequence and understanding protein-protein interactions and protein-ligand interactions. Several studies have described how the interaction between two amino acid side chains have a substantial effect on protein structure and conformational stability. This is under the assumption that the interaction between the two amino acids is independent of surrounding interactions. We are interested in understanding how salt bridges, cation-π, and anion-π interactions affect each other when they are in close proximity. Chapter 1 is a brief introduction on noncovalent interactions and noncovalent interaction cooperativity. Chapter 2 describes the progress we have made measuring the cooperativity between noncovalent interactions involving cations, anions and aromatic amino acids in a coiled-coil alpha helix model protein. Chapter 3 describes cooperativity between cation, anion, and nonaromatic hydrophobic amino acids in the context of a coiled-coil alpha helix. In chapter 4 we describe a strong anion-π interaction in a reverse turn that stabilizes a beta sheet model protein. In chapter 5 we measure the interaction between a cysteine linked maleimide and two lysines in a helix and show that it is a general strategy to stabilize helical structure.

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