High performance liquid chromatography (HPLC) is one of the major techniques in separat-ion sciences. Faster separation and higher efficiency are required to meet ever-growing demands. Despite numerous studies and achievements on improving mass transfer in particulate packings discontinuity seems to be the cornerstone drawback in their development. Macroporous continuous beds or monoliths are therefore a promising alternative to the particle medium. This thesis deals with preparation of new monoliths used as carrier for HPLC. Two different approaches were developed for two polymer systems. One was based on polycondensation of epoxy resins and polyamines which were components of an oil-in-water emulsion. An epoxy resin mixture was dispersed in aqueous polyamine phase with the aid of a surfactant. The other involved a traverse of a ready-made polymer solution around its upper critical solution temperature (UCST). In other words, linear polyamides, non-covalently crosslinked polymers, dissolved in a solvent at temperature higher than their UCST followed by slow cooling to below the critical temperature to precipitate the polymers. Partly re-established hydrogen bonds resulted in the formation of crystallites that interconnected into a network structure. Factors controlling morphology and porosity of final products were investigated. The study also deals with surface modifying for chromatographic applications. Functionalization pathways attempted in the thesis were quaterization of inherent amine of the epoxy-based monoliths and grafting tentacle ion groups via glycidyl methacrylate by atom transfer radical polymerization (ATRP) for ion exchange chromatography (IEC).

No description available.

Background: Meat consumption is associated with an elevated risk of colorectal cancer (CRC); exposure to heterocyclic aromatic amines (HAAs), carcinogens produced when meat is cooked at high temperatures, is one hypothesized explanation for this relationship. HAAs form adducts with DNA; left unrepaired, DNA adducts can induce mutations which may initiate and/or promote the development of colorectal adenomas, precursors to the vast majority of CRCs. Along this continuum, genetic differences in the ability to biotransform or metabolize HAAs and repair DNA is postulated to modify the HAA-CRC relationship. Methods: This thesis examined the HAA-CRC relationship in two studies (Phase 1 and 2). In a cross-sectional study of 99 healthy volunteers, Phase 1 investigated the relationship between dietary exposure to HAAs and the levels of bulky DNA adducts in blood leukocytes. In Phase 2, a cross-sectional study examined the relationships between dietary exposures to: a) HAAs and; b) meat mutagenicity, and the prevalence of colorectal adenomas among 342 patients undergoing a screening colonoscopy. Both Phase 1 and 2 examined potential gene-diet interactions between dietary HAAs and genetic factors relevant to the biotransformation of HAAs and DNA repair. Results: In Phase 1, an interaction was observed for dietary HAAs and NAT1 polymorphisms where a positive association between HAA intakes and bulky DNA adduct levels was found among those with the NAT1 slow acetylator genotype, hypothesized to confer a lower ability to biotransform HAAs. In Phase 2, polymorphisms in genes involved in the biotransformation of HAAs (CYP1B1 rs10012 and rs1056827) and DNA repair (XPC rs2228001) were found to determine colorectal adenoma risk. As well, gene-diet interactions were observed for dietary HAAs/meat mutagenicity exposures and polymorphisms in CYP1B1 and XPD (rs13181 and rs1799793). Overall, a higher risk of colorectal adenoma was observed with higher HAA and/or meat mutagenicity exposures among those with polymorphisms which confer a greater activity to biotransform HAAs and/or a lower ability to repair DNA. Conclusion: This research supports the contribution of dietary HAAs and genetic susceptibility to the risk of developing colorectal adenomas and highlighted bulky DNA adduct formation as a potential biologic pathway through which HAAs may influence cancer risk. / Thesis (Ph.D, Community Health & Epidemiology) -- Queen's University, 2014-04-25 11:32:30.392

<p>Proteins fold into well-defined three-dimensional structures to carry out their biological functions which involve non-covalent interactions with other cellular molecules. Knowledge about the thermodynamic properties of proteins and protein-ligand complexes is essential for answering fundamental biological questions and drug or biomarker discovery. Recently, chemical labeling strategies have been combined with mass spectrometry methods to generate thermodynamic information about protein folding and ligand binding interactions. The work in this thesis is focused on the development and application of two such chemical labeling protocols coupled with mass spectrometry including one termed, SUPREX (stability of unpurified proteins from rates of H/D exchange), and one termed SPROX (stability of proteins from rates of oxidation). The work described in this thesis is divided into two parts. The first part involves the application of SUPREX to the thermodynamic analysis of a protein folding chaperone, Hsp33, and its interaction with unfolded protein substrates. The second part involves the development of a new chemical labeling protocol that can be used to make protein folding and ligand binding measurements on the proteomic scale. </p><p>In the first part of this work, the SUPREX technique was used to study the binding interaction between the molecular chaperone Hsp33 and four different unfolded protein substrates including citrate synthase, lactate dehydrogenase, malate dehydrogenase, and aldolase. The results of the studies, which were performed at the intact protein level, suggest that the cooperativity of the Hsp33 folding/unfolding reaction increases upon binding with denatured protein substrates. This is consistent with the burial of significant hydrophobic surface area in Hsp33 when it interacts with its substrate proteins. The SUPREX derived Kd-values for Hsp33 complexes with four different substrates were also found to be all within a range of 3-300 nM. The interaction between Hsp33 and one of its substrates, citrate synthase (CS), was characterized at a higher structural resolution by using the SUPREX technique in combination with a protease digestion protocol. Using this protocol, the thermodynamic properties for both Hsp33 and CS were evaluated at different stages of binding, including reduced Hsp33 (inactive form), oxidized Hsp33 (active form), followed by native CS and finally of Hsp33ox -CS complexes before and after reduction with DTT. The results suggest that Hsp33 binds unfolded proteins that still have a significant amount of residual higher- order structure. Structural rearrangements of the substrate protein appear to occur upon reduction of the Hsp33-substrate complexes, which may facilitate the transfer of the substrate protein to other protein folding chaperone systems. </p><p>In the second part of this dissertation, a mass spectrometry-based covalent labeling protocol, which relies on the amidination rate of globally protected protein amine groups, was designed and applied to the thermodynamic analysis of several eight protein samples including: six purified proteins (ubiquitin, BCAII, RNaseA, 4OT, and lysozyme with, and without GlcNAc), a five-protein mixture comprised of ubiquitin, BCAII, RNaseA, Cytochome C, and lysozyme, and a yeast cell lysate. The results demonstrate that in ideal cases the folding free energies of proteins and the dissociation constants of protein-ligand complexes can be accurately evaluated using the protocol. Also demonstrated is the new method's compatibility with three different mass spectrometry-based readouts including an intact protein readout using MALDI, a gel-based proteomics readout using MALDI, and an LC-MS-based proteomics readout using isobaric mass tags. The results of the cell lysate sample analysis highlight the complementarity of the labeling protocol to other chemical modification strategies that have been recently developed to make thermodynamic measurements of protein folding and stability on the proteomic scale.</p> / Dissertation

The major goals of this thesis were to: (1) create a site-isolated aminosilica material with higher amine loadings than previously reported isolation methods, (2) use spectroscopic, reactivity, and catalytic (olefin polymerization precatalysts) probes to determine isolation of amine groups on these organic/inorganic hybrid materials, (3) synthesize an organic/inorganic hybrid material capable of activating Group 4 olefin polymerization precatalysts, and (4) synthesize a high amine loaded organic/inorganic hybrid material capable of reversibly capturing CO2 in a simulated flue gas stream. The underlying motivation of this research involved the synthesis and design of novel amine and sulfonic acid materials. Traditional routes to synthesize aminosilicas have led to the formation of a high loading of multiple types of amine sites on the silica surface. Part of this research involved the creation of a new aminosilica material via a protection/deprotection method designed to prevent multiple sites, while maintaining a relatively high loading. As a characterization technique, fluorescence spectroscopy of pyrene-based fluorophores loaded on traditional aminosilicas and site-isolated aminosilicas was used to probe the degree of site-isolation obtained with these methods. Also, this protection/deprotection method was compared to other reported isolation techniques with heterogeneous Group 4 constrained-geometry inspired catalysts (CGCs). It was determined that the degree of separation of the amine sites could be controlled with protection/deprotection methods. Furthermore, an increase in the reactivity of the amines and the catalytic activity of CGCs built off of the amines was determined for aminosilicas synthesized by a protection/deprotection method. The second part of this work involved developing organic/inorganic hybrid materials as heterogeneous Brønsted acidic cocatalysts for activation of olefin polymerization precatalysts. This was the first reported organic/inorganic hybrid sulfonic acid functionalized silica material capable of activating metallocenes for the polymerization of ethylene when small amounts of an alkylaluminum was added. Lastly, an organic/inorganic hybrid hyperbranched aminosilica material capable of capturing carbon dioxide from flue gas streams was synthesized. This material was determined to capture CO2 with capacities higher than currently reported aminosilica adsorbents.

abstract: Carbon capture and sequestration (CCS) is one of the important mitigation options for climate change. Numerous technologies to capture carbon dioxide (CO2) are in development but currently, capture using amines is the predominant technology. When the flue gas reacts with amines (Monoethanaloamine) the CO2 is absorbed into the solution and forms an intermediate product which then releases CO2 at higher temperature. The high temperature necessary to strip CO2 is provided by steam extracted from the powerplant thus reducing the net output of the powerplant by 25% to 35%. The reduction in electricity output for the same input of coal increases the emissions factor of Nitrogen Oxides, Mercury, Particulate matter, Ammonia, Volatile organic compounds for the same unit of electricity produced. The thesis questions if this tradeoff between CO2 and other emissions is beneficial or not. Three different methodologies, Life Cycle Assessment, Valuation models and cost benefit analysis are used to identify if there is a net benefit to the society on implementation of CCS to a Pulverized coal powerplant. These methodologies include the benefits due to reduction of CO2 and the disbenefits due to the increase of other emissions. The life cycle assessment using ecoindicator'99 methodology shows the CCS is not beneficial under Hierarchical and Egalitarian perspective. The valuation model shows that the inclusion of the other emissions reduces the benefit associated with CCS. For a lower CO2 price the valuation model shows that CCS is detrimental to the environment. The cost benefit analysis shows that a CO2 price of at least $80/tCO2 is required for the cost benefit ratio to be 1. The methodology integrates Montecarlo simulation to characterize the uncertainties associated with the valuation models. / Dissertation/Thesis / sima pro / excel sheets / M.S. Civil and Environmental Engineering 2012

Master of Science / Food Science - Animal Sciences and Industry / J. Scott Smith / Heterocyclic amines (HCAs) are a class of mutagenic and carcinogenic chemical compounds formed on the outside of meat and fish when cooked at high temperatures. 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is the most abundantly formed HCA. HCAs have been found to cause cancer in mice and rats; PhIP specifically has been found to cause breast, rectal, prostate, and colon cancers. Model systems are often used to replicate the HCA chemical reactions in meat products without causing the many side reactions when meat is cooked at high temperatures. Model systems are also a useful way to study the effects of different variables and compounds on the formation of HCAs without using meat. A model system using amounts of 0.2 mmol glucose, 0.4 mmol creatinine, and 0.4 mmol phenylalanine in 10:90 water/diethylene glycol (v/v) was used to study the formation of PhIP. Differing levels of black pepper oil, black pepper extract, and rosemary extract (36, 71, 142, 285, 550 μL), synthetic antioxidants BHT and TBHQ (0.05 mmol, 0.1 mmol, 0.2 mmol, 0.4 mmol), and piperine (4.02 mg, 8.04 mg, 16.14 mg, 31.14 mg) were added to the model system to study their effect on PhIP formation. PhIP formation with added BHT (0.2 and 0.4 mmol) and TBHQ (0.4 mmol) were not significantly different from the control. All other added compounds decreased PhIP formation significantly from the control at p < 0.05. Solid phase micro extraction (SPME) headspace analysis was conducted on ground black pepper, black pepper oil, and black pepper extract to determine possible components responsible for PhIP inhibition. Six volatile compounds were found in common between ground black pepper, black pepper oil, and black pepper extract: 1R-α-pinene, 3-carene, caryophyllene, α-caryophyllene, cyclohexene, and D-limonene. D-limonene and caryophyllene had the largest peak areas, suggesting those compounds may play a part in PhIP inhibition in model systems.

Entre as mais importantes propriedades de soluções aquosas micelares está a capacidade de incorporar substâncias orgânicas com diferentes polaridades e graus de hidrofobicidade. Como demonstrado por Quina et aI. (J Phys. Chem., 1995, 99, 11708-11714), um dos métodos mais promissores para a obtenção de correlações entre e a eficiência de solubilização em micelas e as estruturas do soluto e do detergente é através do uso de relações lineares de energia livre (LSERs). No presente trabalho, investigou-se a incorporação de uma série de solutos neutros em micelas dos detergentes zwitteriônicos dimetil-hexadecilamônio-propano sulfonato (CDAPS; 31 solutos) e o N-óxido de dimetil-dodecilamina (DDAO; 33 solutos), bem como em micelas catiônicas da forma protonada de DDAO (DDAOH+; 33 solutos). As constantes de incorporação dos solutos foram determinadas experimentalmente por meio de técnicas fotofísicas, métodos de solubilização e cromatografia líquida e gasosa. A análise dos resultados foi efetuada através de técnicas de regressão múltipla, obtendo-se as seguintes LSERs: CDAPS: Log Ks = - 0,55 + 0,99 R2 - 0,82 &#960;2 + 0,36 &#931;&#945;2 - 0,99 &#931;&#946;2 + 2,73 Vx DDAOH+: Log Ks = - 0,68 + 1,30 R2 - 0,78 &#960;2 + 0,67 &#931;&#945;2 - 1,45 &#931;&#946;2 + 2,29 Vx DDAO: Log Ks = - 0,46 + 0,89 R2 - 0,61 &#960;2 + 0,82 &#931;&#945;2 - 1,66 &#931;&#946;2 + 2,59 Vx onde &#931;&#945;2 e &#931;&#946;2 representam a \"acidez\" e a \"basicidade\" do soluto, com relação à formação de pontes de hidrogênio, R2 corresponde à refração molar em excesso, &#960;2 representa a dipolaridade e Vx é o volume molar do soluto. As LSERs obtidas indicam que os detergentes zwitteriônicos formam sistemas distintos dos demais estudados até o momento. No entanto, os sistemas DDAO e DDAOH+ apresentam LSERs muito semelhantes entre sí, sugerindo que a incorporação dos solutos não é afetada por uma mudança da estrutura (carga) da cabeça do detergente. / One of the most important properties of aqueous micellar solutions is their capacity to incorporate organic solutes with different degrees of polarity and hydrophobicity. As demonstrated by Quina et aI. (J. Phys. Chem., 1995, 99, 1170811714), one of the most promissing methods for obtaining correlations between solubilization eficiency and the solute and surfactant structure is via the use of linear solvation energy relationships (LSERs). The present work investigates the incorporation of a series of neutral solutes in micelles of the zwitterionic detergents hexadecyldimethylammonium propanesulfonate (CDAPS; 31 solutes) and the N-oxide of dodecyldimethylamine (DDAO; 33 solutes), as well as in the cationic micelles of the protonated form of DDAO (DDAOH+; 33 solutes). The incorporation constants were determined experimentally by photophysical techniques, from solubility measurements and by liquid and gas chromatographic methods. Analysis of the results by multiple regression techniques led to the following LSERs: CDAPS: Log Ks = - 0,55 + 0,99 R2 - 0,82 &#960;2 + 0,36 &#931;&#945;2 - 0,99 &#931;&#946;2 + 2,73 Vx DDAOH+: Log Ks = - 0,68 + 1,30 R2 - 0,78 &#960;2 + 0,67 &#931;&#945;2 - 1,45 &#931;&#946;2 + 2,29 Vx DDAO: Log Ks = - 0,46 + 0,89 R2 - 0,61 &#960;2 + 0,82 &#931;&#945;2 - 1,66 &#931;&#946;2 + 2,59 Vx where &#931;&#945;2 and &#931;&#946;2 are the hydrogen bond acidity and basicity of the solute, R2 is the excess molar refraction, &#960;2 is the dipolarity and Vx corresponds to the molar volume of the solute. The LSERs obtained demonstrate that zwitterionic surfactants are distinct from the other systems investigated previously. However, the similarity of the LSERs of DDAO and DDAOH+ suggests that incorporation of solutes is not affected by changes in the structure (charge) ofthe polar headgroup.

The studies on cocrystals and salts presented in the the chapters clearly bring out the influence of intermolecular interactions as the main evaluators of the cocrystal-salt regime. The observations made in Chapter 2 indicate that in case if the cocrystal formation is through hydrogen bonds the location of the proton decides the nature of the complex in the energy landscape. The observation that the coformer controls the topology of intermolecular space as demonstrated in Chapter 3 provides insights into the importance of directionality rather than strength of intermolecular interactions. Indeed halogen bonding in cocrystals gain importance in this context.

Kirala aminer används idag både som aktiva substanser och som bindningsmedel i flertalet läkemedel, dock är dagens produktion med kinetic resolution ineffektiv vilket gör att mer effektiva och miljövänliga produktionssätt eftersträvas. Biotransformation har visat sig både vara miljövänligt och en effektiv metod för att producera kirala aminer. Aminosyror kan användas som aminodonatorer för att producera den kirala aminen 1-methyl-3-phenylpropylamine (MPPA) från prokirala ketonen bensylaceton (BA) med hjälp av aminetransaminas. I denna studie användes metaboliskt konstruerad Saccharomyces cerevisiae med enzymet CV-ωTA för att identifiera vilka aminosyror som var bäst lämpade för MPPA produktion. MPPA produktion kunde detekteras för alla testade aminosyror. Aminosyrans koncentration hade ingen tydlig påverkan på produktionen av MPPA. Alanin vara den aminosyra som gav högst produktionsutbyte följt av lysin. Ingen tydlig relation mellan produktion av MPPA och aminosyrornas koncentrationer kunde ses. Produktionen av MPPA var snabbare än förväntat och var klar redan dag tre för flera av aminosyrorna. Det fanns en antydan att BA kunde vara toxiskt för cellerna i högre koncentrationer och därmed påverka produktionen av MPPA. / Chiral amines are used in several types of pharmaceuticals as both active substrates and building blocks, and there is an endeavor to find new and more eco-efficient ways to produce them than today’s production with kinetic resolution. Biotransformation in yeast has shown great potential for production and is also seen as an eco-friendly way to produce chiral amines. Amino acids can be used as an amino donor for the production of chiral amines, e.g. 1-methyl-3-phenylpropylamine (MPPA) from prochiral ketones, e.g. benzylacetone (BA) with aminotransaminase. In this study the production was done with metabolically engineered Saccharomyces cerevisiae, with the gene for the enzyme CV-ωTA transformed. Ten different amino acids were screened in up to three different concentrations for each amino acid. Production of MPPA was observed for all amino acids, with alanine as the most efficient followed by lysine. No clear relationship was seen between amino acid concentration and MPPA production. The production of MPPA for several amino acids were quicker than expected and was completed at day three. Our data indicated a cytotoxic effect of BA at higher concentrations, that negatively affected the production of MPPA.