Chemistry Commons^™

Synthesis And Identification Of An Investigational Essential Precursor Compound For The Purpose Of The Development Of A Vaccine Treatment Against The Peanut Allergy, Thomas F. Anguella

Theses and Dissertations

Presented in this master's thesis are several studies carried out to determine the viability of several allergoid candidates utilizing the major peanut allergen Ara h 2. The Ara h 2 allergen protein appears naturally as a doublet when observed by gel electrophoresis, SDS-PAGE. Optimization of allergen purification methods successfully led to Ara h 2 purity, and the ability to standardize procedures to yield consistently pure samples. The purified allergen was chemically crosslinked with diketone derivatives selected for their abilities to react with specific amino acids accessible on the Ara h 2 protein. Chemically modified allergen samples were also evaluated using …

Development Of Novel Therapeutic Approaches: (I) Targeting Allergic Responses To Peanuts And (Ii) Inhibition Of Dpp-Iv Enzyme Involved In Diabetes, Savan V. Patel

Theses and Dissertations

There is an increase in prevalence of peanut allergy, especially in the western world. The only current treatment for peanut allergy is avoidance of peanut from diet and contact. Additionally, there is currently no specific vaccine that can be taken to decrease peanut allergies. The method of desensitizing a person allergic to peanut allergy is deemed unsafe as the smallest amount of peanut can trigger an anaphylaxis reaction. Thus, various allergoids were created by modifying major peanut protein allergen Ara h2 using various cross-linkers and modification agents in order to disrupt the binding surface epitopes of the antigen to antibody. …

Development Of New Routes For The Synthesis Of Carbaporphyrins And Carbachlorins, Navneet Sahota

Theses and Dissertations

Carbaporphyrins and carbachlorins are porphyrin analogs in which one of the nitrogens is replaced with a carbon atom within a porphyrin-like cavity. These systems form stable organometallic derivatives and exhibit unusual chemical reactivity. In the monocarbaporphyrinoids such as benzocarbaporphyrins, one of the pyrrole rings is replaced by an indene unit. Although syntheses of monocarbaporphyrins with fused rings have been widely investigated over the past 20 years, a few examples of carbaporphyrins without fused rings have been reported in the literature.

In this thesis, two projects were conducted to further explore carbaporphyrin and carbachlorin chemistry. The first project utilized a ‘3+1’ …

Parameterization Of Ar231453: A Potent Agonist Of The Gpr119 Receptor, A Target For Diabetes Treatment, John E. Hamilton

Theses and Dissertations

The first reported potent agonist for the GPR119 receptor, a potential target for the treatment of diabetes, is 2-fluoro-4-methanesulfonyl-phenyl-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine (AR231453). The dynamic interactions of AR231453 with GPR119 using molecular dynamics simulation are of great interest. However, parameters for AR231453 that describe the behavior of the molecule in the CHARMM force field have not been determined. The following study produces parameters by creating model fragments and compares the produced parameters to quantum calculations. The produced parameters are then further refined within the Visual Molecular Dynamics (VMD) program’s plugin program, the Force Field Toolkit as well as Gaussian 09 and CHARMM. Molecular …

Desorption Electrospray Ionization (Desi) Mass Spectrometric Imaging Of Spatially Regulated In Vivo Metabolic Rates, Charlotte Reininger Lewis

Theses and Dissertations

Desorption electrospray ionization (DESI) is an ambient ionization technique used for mass spectrometric imaging of biological samples. When coupled with isotopic ratio measurements of deuterium-labeled tissues, DESI provides a means of measuring metabolic rates on a spatially resolved basis. In vivo metabolic rates are desired to better understand diseases such as Alzheimer's, Parkinson's, Huntington's, and various forms of cancer that negatively impact metabolic rates within different organs of the human body. Although DESI has been used to image lipids and metabolites of a variety of tissues and other imaging techniques, such as NIMS, have been used to study kinetic turnover …

Formation Of Lifepo4-Pan Submicron Fibers Via Forcespinning ® For Battery Cathode Applications, Ashlee L. Lopez

Theses and Dissertations

LiFePO4/C composite nanofibers were prepared by utilizing Forcespinning® technology and calcination approaches. Polyacrylonitrile (PAN) was dissolved in N, N-dimethylformamide (DMF) to produce the media that allotted nanofiber formation via Forcespinning® and also served as the carbon source. A LiFePO4 solution was synthesized separately in DMF, which served as the precursor. The separately prepared PAN/DMF and LiFePO4/DMF solutions were then mixed at different weight percent’s (wt.%) prior to being subjected to Forcespinning ®. Elemental analysis of the LiFePO4/PAN nanofibers was characterized by energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS). The study of the surface morphology was conducted by scanning …

Characterization Of Sufs And Sufe Of Suf Pathway For Fe-S Cluster Assembly In Escherichia Coli, Guangchao Dong

Theses and Dissertations

Fe-S clusters are one major type of the sulfur-containing cofactors, which conduct essential functions in organisms. The Suf pathway is one of the three main pathways for the biosynthesis of Fe-S clusters. In E. coli, the Suf pathway is utilized under iron limitation and oxidative stress. This ability is important for pathogens to survive. Also, the Suf pathway is found to be exclusive in bacteria, so it is a good target for novel antibiotic design. SufS is a cysteine desulfurase in the Suf pathway to extract sulfur from L-cysteine. It needs the enhancement of SufE. To better understand the catalytic …

Advances In Chemistry, Part I: Noise, Calibration, And Educational Advances In Analytical Chemistry. Part Ii: Safety Oversight In Chemical Journals, Lauren E. Grabowski

Theses and Dissertations

Part I:

The accuracy and precision of the results of any chemical analysis depends on the calibration graph and its associated systematic and random errors. Least squares regression generally treats all data with equal weights. A weighted least-squares fit is an improvement but requires knowledge of the imprecision in each point of the calibration graph. The imprecision is not easy to estimate with high confidence because of the large number of replicates needed.

The imprecision depends on the types and magnitudes of the sources of noise. We characterized the noise sources in ICP-OES and UV/Vis and developed a model that …

Antimicrobial Biomaterials And Sustainable Polymers From Renewable Biomass, Mitra Shiran Ganewatta

Theses and Dissertations

In this dissertation, development of antimicrobial biomaterials and sustainable polymers from renewable biomass is described. In Chapter 1, an overview and recent development about sustainable polymers from renewable biomass, antimicrobial biomaterials and polymerization methods are given. Afterwards, the major research objectives of this doctoral research work are described.

Innovative cationic polymers containing pine resin sourced abietic acid is discussed in Chapter 2. The preparation of cationic compounds is conversed via a combination of Diels-Alder, catalytic esterification, quaternization and subsequent decoration of polycaprolactone that was prepared via ring-opening polymerization (ROP). Furthermore, the antimicrobial activity against a range of bacteria, biocompatibility with …

Shaping Metallic Nanoparticles Toward Integrated Plasmonics And Catalysis, Qingfeng Zhang

Theses and Dissertations

Noble metal nanoparticles have been of tremendous interest because of their intriguing size- and shape-dependent plasmonic and catalytic properties. The combination of tunable plasmon resonances with superior catalytic activities on the same nanoparticle, however, has long been challenging because plasmonics and catalysis require nanoparticles in two drastically different size regimes. Tunable plasmon resonances is a unique feature of sub-wavelength metallic nanoparticles, whereas heterogeneous catalysis requires the use of sub-5 nm nanoparticles as the catalysts. In this dissertation, I firstly found a unique way to bridge this size gap between nanoplasmonics and nanocatalysis. I demonstrated that desired plasmonic and catalytic properties …

Part (I): Synthesis, Characterization And Antibacterial Activity Of Vanadium(V) Complexes With Ons Schiff Bases Part (Ii): Synthesis Of 9-Cd₃-11-Cis-Retinal For The Investigation Of The Activation Mechanism Of Gpcr Rhodopsin By Solid-State ²H Nmr Spectroscopy, Samira M. Faylough

Theses and Dissertations

Vanadium compounds are known to play many roles in both biology and industry, and the biochemical activity of these compounds has led to their increased importance in both biological and medical research. In the present work, some new substituents for hydrazinecarbodithioate Schiff base ligands and their dioxo vanadium(V) complexes were synthesized and characterized by ¹H NMR, ¹³C NMR, DART mass, FT-IR, UV-vis, fluorescence spectrometer, and single X-ray diffraction analysis for complex K[VO₂{(S-benzyl-3-(2-hydroxy-5-nitrophenyl) methylene dithiocarbazate)}] (212). Dioxovanadium(V) complexes K[VO₂{(S-methyl-3-(2-hydroxy-5-nitrophenyl)methylenedithiocarbazate)}] (211) and 212 have been tested for antibacterial activity against Burkholderia pseudomallei and Burkholderia mallei strains. Ceftazidime was used as a reference …

Cytotoxic And Antimicrobial Effects Of Silver-Containing Surfaces, Sarah Goderecci

Theses and Dissertations

This study examines applications of sputtered silver coatings as alternatives to traditional antibiotic treatments. Given the increase in reports of antibiotic-resistant bacteria, new treatments and coatings for in-dwelling medical devices such as catheters and orthopedic implants are necessary. Silver oxide films were deposited onto Ti surfaces to examine the efficacy of such coatings against a variety of bacterial species both in vitro and in vivo. Bacterial growth studies showed that coatings exhibited antimicrobial activity against a range of bacterial species acting either in a bacteriostatic or bactericidal mechanism, depending on the target. Limited toxicity to in vitro mammalian cells was …

Formation, Characterization, And Optimization Of Antibody-Gold Nanoparticle Conjugates, Seth L. Filbrun

Theses and Dissertations

Protein modified gold nanoparticle based immunoassays are the basis of many novel detection techniques. There are many groups working on novel immunoassays but there is still much to understand about how many proteins are attached onto each nanoparticle and much to improve on immobilization methods. This thesis work is devoted to improving techniques for the quantification of protein immobilized on the gold nanoparticle and development of a novel approach to immobilize protein independent of pH.

The ability to evaluate antibody immobilization onto gold nanoparticles is critical for assessing coupling chemistry and optimizing the sensitivity of nanoparticle-enabled biosensors. Herein, we developed …

Theoretical And Experimental Analysis Of Optical Properties Of Defects In Gan:, Ibrahima Castillo Diallo

Theses and Dissertations

Using the Heyd-Scuseria-Ernzherof (HSE06) hybrid functional method along with photoluminescence experimental measurements, we analyze the properties of intrinsic defects such as vacancies, interstitials, antisites, and common complexes. By using configurational coordinate diagrams, we estimate the likelihood of defects to be radiative or non-radiative. Our calculations show that gallium vacancies exhibit a large magnetic moment in the neutral charge state and are most likely non-radiative. We also investigate the correlation between the observed infrared PL bands created in 2.5 MeV electron-irradiated GaN samples and the formation of native defects. It is found that gallium-nitrogen divacancies are possible sources of the broad …

Synthesis, Characterization, And Enhanced Magnetic Properties Of Iron Carbide Nanomaterials, Brent M. Williams

Theses and Dissertations

Permanent magnets are classified as hard magnetic materials with the main purpose of generating flux for applications such as electric motors, turbines, and hard drives. High coercivity, magnetic remanence, and saturation values with high stability are some of the requirements for permanent magnets. Rare-earth magnets including neodymium and samarium based magnets are known to have superior magnetic properties due to their high magnetocrystalline anisotropy. However, due to the price of rare-earth materials development of alternate permanent magnets composed of inexpensive materials is an ongoing process. Previously cobalt carbide (Co_xC) have shown promise as a potential rare-earth free magnet …

The Development Of Novel Hybridized Hyaluronic Acid Biomaterials For Applications In Tissue Engineering And Controlled Drug Delivery, Panita Maturavongsadit

Theses and Dissertations

This thesis is focused on the development of novel hybridized biomaterials for applications in tissue engineering and controlled drug delivery. Two types of materials used in my research are biopolymers and nanomaterials. Hyaluronic acid (HA), a natural polymer commonly found in extracellular matrix (ECM), was the primary polymer used in my research due to biocompatibility, biodegradability and the ease of manipulation to offer a wide range of physical and mechanical properties. Meanwhile, the nanomaterials, including Tobacco mosaic virus (TMV), gold nanorods and graphene, provide attractive properties, such as a nanoscale topography, biochemistry, high surface area, and special chemical and electrical …

Quantitative Analysis Of Tobacco-Specific Nitrosamines And Their Precursor Alkaloids In Tobacco Extracts, Celeste T. Wilkinson

Theses and Dissertations

Tobacco-specific nitrosamines (TSNA) are carcinogenic constituents derived from alkaloids in tobacco. Researchers are actively exploring several avenues to reduce TSNA levels in tobacco products like moist snuff tobacco. The focus of the research presented within is the quantitative analysis of TSNA in tobacco, specifically N’-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1(3-pyridyl)-1-butanone (NNK), N’-nitrosoanatabine (NAT), and N’-nitrosoanabasine (NAB).

Tobacco alkaloids and nitrosamines in tobacco are currently analyzed by different instrumentation due to orders of magnitude difference in their concentrations, chromatographic separation challenges due to structural similarities, and similar mass fragmentation patterns. An analytical column using silica and 1,2-bis(siloxy)ethane hybrid particles of 1.7 µm size is …

Fast Scan Cyclic Voltammetry For Real-Time Metal Speciation Analysis, Hettige. M. Thushani Siriwardhane

Theses and Dissertations

Electrochemistry is a powerful analytical tool that has been widely used to detect trace metals in natural systems. However, studying the speciation of metals during dynamic events, such as storms and floods, is analytically challenging due to the limited temporal resolution of traditional electrochemical techniques. Additionally, most techniques report the total metal concentration (both complexed and free) that does not reflect the toxicity of these metals, which arise mostly from the free state. To overcome these issues, we previously pioneered the use of fast scan cyclic voltammetry (FSCV) to measure free copper (Cu(II)) and lead (Pb(II)) in real-time in laboratory …

Development Of An Electrochemical Method To Study Real-Time In Vivo Neurotransmitter Modulation, Srimal Aminda Samaranayake

Theses and Dissertations

Histamine and serotonin are important biogenic amines that regulate vital brain functions. These two transmitters are thoughts to be involved in neurodegenerative diseases such as Parkinson’s and Alzheimer’s and affective disorders including depression. Histamine and serotonin are believed to regulate each other but their fundamental neuromodulation mechanisms are not well understood. This lack of understanding makes brain disorders implicating these two transmitters difficult to diagnose and treat. Our lab extensively investigates the serotonergic system to understand serotonin’s neurochemistry in the brain. However, histamine is relatively understudied with respect to other biogenic amines because of an absence of suitable analytical tools. …

Fluorescence Polarization Measurements To Probe Alignment Of A Bithiophene Dye In One-Dimensional Channels Of Self-Assembled Phenylethynylene Bis-Urea Macrocycle Crystals, Preecha Kittikhunnatham

Theses and Dissertations

This thesis describes the use of polarized fluorescence microscopy to directly probe guest molecule orientation in bis-urea macrocycle crystals. These macrocycles assemble to afford one-dimensional (1D) microchannels ∼9 Å in diameter that have previously been shown to exhibit normal Fickian diffusion and induce selective reactivity among the confined guest molecules. In the present work, we take advantage of the quasi-1D morphology of fiber-like microcrystals with the extended dimension corresponding to the channel axis to measure excitation and emission polarization values for a bithiophene guest. Guest fluorescence is shown to be polarized along the fiber axis with emission polarization values up …

Synthesis, Characterization And Application Of Polymer-Grafted Nanoparticles, Yang Zheng

Theses and Dissertations

This work focused on the synthesis and characterization of polymer-grafted nanoparticles for various applications including drug-delivery, directed self-assembly and mechanical reinforcement applications. The surfaces of inorganic particles were modified with polymers of different composition, chain length, graft density and polymer architecture depending on the specific needs of each project. The surface modifications were mainly achieved by surface-initiated reversible addition fragmentation chain transfer (RAFT) polymerization, which is a very versatile technique to prepare nanocomposites with desired properties.

The first part of this work (Chapters 2 & 3) focused on novel self-assembly techniques. Chapter 2 described the design and characterization of a …

Functional And Mechanistic Insight Into The Role Of Atg9a In Autophagy, Vajira Kaushalya Weerasekara

Theses and Dissertations

The bulk degradative process of macroautophagy requires the dynamic growth of autophagosomes, which carry cellular contents to the lysosome for recycling. Atg9A, a multi-pass transmembrane protein, is an apical regulator of autophagosome growth, yet its regulatory mechanism remains unclear. Our work suggests that hypoxia (low glucose and oxygen) triggers a rearrangement of the small adapter protein 14-3-3ζ interactome. Our data suggest that the localization of mammalian Atg9A to autophagosomes requires phosphorylation on the C terminus of Atg9A at S761, which creates a 14-3-3z docking site. Under basal conditions, this phosphorylation is maintained at a low level and is dependent on …

Design, Cloning, And Expression Of Rat Preptin And Alanine Analogs, Jahbo M. Love

Theses and Dissertations

Alanine scanning mutagenesis was employed to determine the structural epitopes of preptin; a newly discovered polypeptide found on the proinsulin-like growth factor II. The alanine scanning mutagenesis was accomplished by the use of, cloning, affinity chromatography, gel electrophoresis, gene sequencing, and mass spectra. However, due to inconclusive results, more research is required before the epitopes can be elucidated.

Efficient Integration Of Plasmonic And Excitonic Properties Of Metal And Semiconductor Nanostructures Via Sol-Gel Assembly, Dilhara Liyanage

Theses and Dissertations

Research in nanoscience has gained noteworthy interest over the past three decades. As novel chemical and physical properties that are vastly different from extended solids are realized in nanosized materials, nanotechnology has become the center of attention for material in research community. Much to our amazement, investigations in the past two decades revealed that the nanocrystalline semiconductors are “THE PRIME CANDIDATES” to meet the growing energy demand, sensor development, cellular imaging and a number of other optoelectronic applications. Nonetheless, synthesis of nanostructures with control over physical parameters is not sufficient, yet assembling them into functional nanoarchitectures with unique and tunable …

Materials Discovery Of Reduced Early Transition Metal Compounds: Crystal Growth And Characterization, Dileka Abeysinghe

Theses and Dissertations

Materials discovery via crystal growth is an active area of research that has led to the preparation of many novel materials along with the determination of their crystal structures. One sub-category in this diverse field of materials is the preparation of early transition metal reduced oxides. These reduced oxides often exhibit unusual electronic and magnetic properties. Due to the synthetic challenges associated with early transition metal reduction, new and facile methods to prepare reduced oxides is of great interest. These limitations can be overcome by using a carefully selected redox neutral flux, a vacuum sealed fused silica tube, and metal …

Kinetic-Control Of Block Copolymer Micelles For Tunable Nanomaterials Towards Energy Devices, Hasala Nadeesini Lokupitiya

Theses and Dissertations

Nano-scale inorganic porous materials are crucial for numerous applications ranging from electronics to energy conversion. The ability to control the morphology and the key architectural parameters of nanomaterials largely determines the transport characteristics and performance of such devices. But, there is very little understanding and development to tune these key architectural parameters such as inorganic wall-thickness and pore diameter. Even though there are numerous examples available on the fabrication of porous nanomaterials via block copolymer co-assembly, there is limited understanding on independent control over key architectural parameters. Because of that the major focus of this thesis is to explore and …

Coordination Chemistry Of Carboranes And Furan Ligands On Transition Metal Cluster Complexes, Emmanuel Joseph Kiprotich

Theses and Dissertations

Chapter 1 presents the most relevant literature in the field of carborane chemistry. The focus is on icosahedral carboranes and the different methods of boron or carbon atoms substitution and functionalization. The direct addition of transition metal to boron atoms is covered in detail as well as strategies for cage opening of icosahedral carboranes.

Chapter 2 reports the preparation of some of the first polynuclear metal carbonyl cluster complexes where the closo-carborane cage: o-C₂B₁₀H₁₂ serves as a ligand on the face of one (Os₃(CO)₉(µ₃-4,5,9-C₂B₁₀H_{10 …}

Elucidation Of Protein Interactions And The Re-Tuning Of Porphyrin Electronics For Hydroxylases, Steven Charles Ratigan

Theses and Dissertations

Non-Ribosomal Peptide Synthetases (NRPSs) and their exogenous tailoring partners have been heavily studied but not in the context of non-cognate systems. Orf78, a dinuclear iron β-hydroxylase from the lysobacter pathway and homologous to CmlA from the chloramphenicol pathway, is used to test affinities for one native and two non-native T-domains. Results indicate that there is enough difference between Type I and Type II NRPS systems to disfavor common recognition motifs. Additionally, the β-hydroxylase P450sky, from the skyllamycin biosynthetic pathway, is used in conjunction with the NRPS ATdomain NikP1AT from the nikkomycin biosynthetic pathway, in lieu of the homolog P450nikQ. The …

Silylation-Based Kinetic Resolution Of 2-Arylcyclohexanols And Understanding Internal Chirality Transmission Via Circular Dichroism, Li Wang

Theses and Dissertations

This work described herein focuses on the silylation-based kinetic resolution methodology developed by the Wiskur group in 2011. It is a powerful method for the separation of a single enantiomer from a mixture of racemic secondary alcohols. Chapter one is a summary of the background and related works of this methodology.

In chapter two, the silylation-based kinetic resolution of various trans 2-arylcyclohexanols will be discussed by employing a p-isopropyl triphenylsilyl chloride as the derivatizing reagent with (-)-benzotetramisole as the catalyst. The diastereoselective and enantioselective of trans alcohols over the cis will be investigated and a facial one-pot reaction sequence will …

Redirecting P450 Ferryl-Oxo Intermediates From Oxygenation To Decarboxylation, Job Logan Grant

Theses and Dissertations

A recently discovered cytochrome P450 has garnered much interest for its ability to oxidatively decarboxylate n length fatty acids to n-1 terminal olefins using hydrogen peroxide as an oxidant. This enzyme (P450 OleT) is mechanistically peculiar, as it seemingly abrogates the oxygen insertion chemistry that typifies the P450 superfamily. In this work we explore the origin of this deviant catalysis.

Using stopped-flow and transient kinetic methodologies the ferryl-oxo pi-cation radical and ferryl-hydroxo intermediates, known as compound-I (Cpd-I) and compound-II (Cpd-II) respectively, were isolated in high yield. This is the first time either species has been observed in a substrate bound …