Digital Commons Network^™

Cest And Paracest Mr Contrast Agents, Ileana Hancu, W. Thomas Dixon, Mark Woods, Elena Vinogradov, A. Dean Sherry, Robert E. Lenkinski

Chemistry Faculty Publications and Presentations

In this review we describe the status of development for a new class of magnetic resonance (MR) contrast agents, based on chemical exchange saturation transfer (CEST). The mathematics and physics relevant to the description of the CEST effect in MR are presented in an appendix published in the online version only. We discuss the issues arising when translating in vitro results obtained with CEST agents to using these MR agents in in vivo model studies and in humans. Examples are given on how these agents are imaged in vivo. We summarize the status of development of these CEST agents, and …

Comparing The Chelating Abilities Of N-Acetylcysteine And N-Acetylcysteine Amide In Vitro For Lead Poisoning Treatment, Weiqing Chen

Masters Theses

"Lead poisoning is a perennial and serious health problem around the world. The daily widespread use of lead has dramatically increased the degree and longevity of its exposure to humans, exacerbating the task of lead poisoning treatment. Lead exerts adverse effects on cardiovascular, central nervous, renal, gastrointestinal, and reproductive systems. The common treatment for lead poisoning is chelation therapy. Chelators were proposed to treat lead poisoning a very long time ago. However, chelators have severe side effects that could cause more problems, in addition to lead poisoning. Therefore, another group of drugs has been suggested --- antioxidants. This type of …

Free-Standing And Reactive Thin Films Fabricated By Covalent Layer-By-Layer Assembly And Subsequent Lift-Off Of Azlactone-Containing Polymer Multilayers, Maren E. Buck, David M. Lynn

Chemistry: Faculty Publications

We report an approach to the fabrication of free-standing and amine-reactive thin films that is based on the reactive layer-by-layer assembly and subsequent lift-off of azlactone-containing polymer multilayers. We demonstrate that covalently cross-linked multilayers fabricated using the azlactone-functionalized polymer poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) and a primary amine-containing polymer [poly(ethyleneimine) (PEI)] can be delaminated from planar glass and silicon surfaces by immersion in mildly acidic aqueous environments to yield flexible freestanding membranes. These free-standing membranes are robust and can withstand exposure to strong acid, strong base, or incubation in high ionic strength solutions that typically lead to the disruption and erosion of polymer …

Langmuir Films Of Flexible Polymers Transferred To Aqueous/Liquid Crystal Interfaces Induce Uniform Azimuthal Alignment Of The Liquid Crystal, Michael I. Kinsinger, Maren E. Buck, Maria Victoria Meli, Nicholas L. Abbott, David M. Lynn

Chemistry: Faculty Publications

We reported recently that amphiphilic polymers can be assembled at interfaces created between aqueous phases and thermotropic liquid crystals (LCs) in ways that: (i) couple the organization of the polymer to the order of the LC and (ii) respond to changes in the properties of aqueous phases that can be characterized as changes in the optical appearance of the LC. This investigation sought to characterize the behavior of aqueous-LC interfaces decorated with uniaxially compressed thin films of polymers transferred by Langmuir-Schaefer (LS) transfer. Here, we report physicochemical characterization of interfaces created between aqueous phases and the thermotropic LC 4-cyano-4′-pentylbiphenyl (5CB) …

Synthesis Of Some New Biheterocyclic Triazole Derivatives And Evaluation Of Their Antimicrobial Activity, Hakan Bektaş, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Şengül Alpay Karaoğlu

Turkish Journal of Chemistry

2-{3-(4-Substitutedbenzyl)-4-[2-(1H-indol-3-yl)ethyl]-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl}-N'-(aryl-methylene)acetohydrazides (5a-g), 4-amino-2-{-(4-substitutedbenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol- 1-yl}-N'-(arylmethylene)acetohydrazides (6a,b), and 4-[2-(1H-indol- 3-yl)ethyl]-5-(4-substitutedbenzyl)-2-{5-(phenylamino)-1,3,4-thiadiazol- 2-yl]methyl}-2,4-dihydro-3H-1,2,4-triazol-3-ones (8a,b) were synthesized starting from 4-alkyl-5-(4-substitutedbenzyl)-2,4-dihydro- 3H-1,2,4-triazol-3-ones (2a-c) by several steps and their structures were well characterized by elemental analyses, IR, ^1H-NMR, ^{13}C-NMR, and mass spectral studies. They were also screened for their microbial activities. The obtained antimicrobial activity results revealed that 12 among the 24 compounds tested displayed variable growth inhibition effects on the tested gram-positive and gram-negative bacterial strains. None of the compounds showed antifungal activity against yeast-like fungi.

Chelating Agent Free Solid Phase Extraction (Caf-Spe) Method For Separation And/Or Preconcentration Of Iron(Iii) Ions, Özcan Yalçinkaya, Orhan Murat Kalfa, Ali̇ Rehber Türker

Turkish Journal of Chemistry

This paper presents a chelating agent free solid phase extraction (CAF-SPE) method for the separation and/or preconcentration of trace iron(III) ions. This method is based on the sorption of Fe(III) ions without using any chelating agent onto Amberlyst 36 resin. A good relative standard deviation (3%), high recovery (>95%), high enrichment factor (100), and low detection limit (0.32 \mu g L^{-1}) were obtained. The adsorption capacity of resin was 117 mg g^{-1} for iron(III). The method was applied for the determination of iron various in water and commercial tea bag samples. The accuracy of the method was confirmed by …

Sulfonic Acid-Functionalized Silica: A Remarkably Efficient Heterogeneous Reusable Catalyst For The One-Pot Synthesis Of 1,4-Dihydropyridines, Behzad Mohammadi, Sayyed Mohammad Hosseini Jamkarani, Taghi A. Kamali, Mahmoud Nasrollahzadeh, Ali Mohajeri

Turkish Journal of Chemistry

An efficient one-pot method for the synthesis of 1,4-dihydropyridines from \beta-dicarbonyl compounds, aldehyde, and ammonium acetate is reported using sulfonic acid-functionalized silica at 90 °C under solvent-free conditions with good to excellent yields. The catalyst is easily prepared, stable (up to 300 °C), reusable, and efficiently used under reaction conditions.

Synthesis And Surfactant Properties Of N-Acylation Compounds Derived From Hydrolysis Degradation Products Of N-(\Beta-Cianoethyl)-\Epsilon-Caprolactam, Andreea Bondarev

Turkish Journal of Chemistry

N-acyl amino acids can be used as active surface agents in the detergents industry, as well as in the pharmaceutical industry and cosmetics. Properties of these compounds are superior to those of fatty acids soaps and they are not toxic to the environment and have low Kraft points, because of peptide bonds (CO-NH). Acylation at the nitrogen atom can be performed with good yields without catalysts, for strong nucleophilic derivatives. The synthesis of some derivatives of 4-azasebacic acid, which are hydrolysis degradation products from N-(\beta -cianoethyl)-\epsilon -caprolactam, has been described and the N-acylation processes for these compounds are also presented. …

Energy Of The Conduction Band In Near Critical Point Fluids, Cherice M. Evans, G. L. Findley

Publications and Research

The study of the evolution of the conduction band in dense gases and supercritical fluids near the critical point has been complicated by a lack of precise experimental measurements. Both photoemission from an electrode immersed in the fluid and field ionization of a molecule doped into the fluid have been used to probe solvent density effects on the energy of an excess electron as a function of fluid number density and temperature. In this perspective, we present recent experimental results that show a strong critical point effect on the minimumconduction band energy near the critical density and temperature of a …

Synthesis And Conjugation Of Terminal Α-Galactose Containing, Roger Allan Ashmus

Open Access Theses & Dissertations

Over 16 million people in Latin America are infected with the protozoan parasite Trypanosoma cruzi (T. cruzi), the causative agent of Chagas disease, and up to 50,000 infected people die annually due to complications during the chronic stage of the disease. To date, there are no vaccines or effective drugs to treat chronic Chagas disease. It is known that T. cruzi contains cell surface mucin-like glycoproteins with terminal α-galactosyl residues, and it is well established that they are highly immunogenic. The exact structure of the immunogenic carbohydrate epitopes, however, remains unknown. To determine which epitopes have the ability to interact …

Immobilization Of Mercury And Arsenic Through Covalent Thiolate Bonding For The Purpose Of Environmental Remediation, Lisa Y. Blue

University of Kentucky Doctoral Dissertations

Mercury and arsenic are widespread contaminants in aqueous environments throughout the world. The elements arise from multiple sources including mercury from coal-fired power plants and wells placed in natural geological deposits of arseniccontaining minerals. Both elements have significant negative health impacts on humans as they are cumulative toxins that bind to the sulfhydryl groups in proteins, disrupting many biological functions. There are currently no effective, economical techniques for removing either mercury or arsenic from aqueous sources. This thesis will demonstrate a superior removal method for both elements by formation of covalent bonds with the sulfur atoms in N,N’-Bis(2-mercaptoethyl)isophthalamide (commonly called …

Opioid-Cannabinoid Codrugs With Enhanced Analgesic And Pharmacokinetic Profile, Harpreet Kaur Dhooper

University of Kentucky Doctoral Dissertations

The central hypothesis of the dissertation is that “the design and synthesis of a codrug of an opiate and a cannabinoid can be achieved which is stable in the gastrointestinal tract and shows a superior pharmacological and pharmacokinetic profile when compared to a physical mixture of the two parent drugs.” To prove the hypothesis, a series of novel codrugs were prepared by conjugation of the opiate drug codeine with Δ⁹-tetrahydrocannabinol (Δ⁹-THC), cannabidiol, abn-cannabidiol and an opiate prodrug 3-O-acetylmorphine with Δ⁹-THC. Codeine-cannabinoid codrugs were evaluated for analgesic activity in the rat after oral administration. The …

Synthesis And Manufacture Of Photocrosslinkable Poly(Caprolactone)-Based 3d Scaffolds For Tissue Engineering Applications, Nathan Jonathan Castro

Open Access Theses & Dissertations

It is known that the body can efficiently repair hard tissue (bone) micro fractures by suturing the defect through the deposition of minerals resulting in an area that is stronger post-injury. Larger defects, however, generally cause more trouble since the body is incapable of repairing them. Bone defects can occur as a result of congenital abnormalities, trauma, or disease. Traditional methods for addressing these defects have involved the use of acellular cadaverous bone or autologous bone. Both contain innate problems associated with them; the former method can result in disease transmission, as well as very low integration with the host …

A New Photochemical Method For The Preparation Of Amino Acid-α-Phenylthioesters And Peptide-α-Phenylthioesters, Tyrone Hogenauer

Open Access Theses & Dissertations

We describe the development of a novel resin with a photoreactive N-acylnitroindoline linker that allows for the synthesis of amino acid- (in solution) or peptide-α-thioesters using standard Fmoc/t-Bu standard solid phase peptide synthesis (SPPS). Recent advances have shown that the yields of this thioesterification reaction have dramatically increased due to a simple change in the order of addition of reagents. Upon illumination with UV-light, in the presence of N-hydroxybenzotriazole (HOBt), the amino acid- or peptide-α-OBt ester is generated by direct photo-release from the nitroindoline linker with minimal epimerization, followed by reaction with thiophenol in the dark to produce amino acid-α-phenylthioesters …

A New Green Chemistry Method Based On Plant Extracts To Synthesize Gold Nanoparticles, Milka Odemariz Montes Castillo

Open Access Theses & Dissertations

Extraordinary chemical and physical properties exhibited by nanomaterials, as compared to their bulk counterparts, have made the area of nanotechnology a growing realm in the past three decades. It is the nanoscale size (from 1 to 100 nm) and the morphologies of nanomaterials that provide several properties and applications not possible for the same material in the bulk. Magnetic and optical properties, as well as surface reactivity are highly dependent on the size and morphology of the nanomaterial. Diverse nanomaterials are being widely used in molecular diagnostics as well as in medicine, electronic and optical devices. Among the most studied …

Understanding The Promotion Effect: A Density Functional Theory Study Based On High Resolution Transmission Electron Microscopy Images For Mos2-Cobalt Promoted Interfaces, Manuel A. Ramos

Open Access Theses & Dissertations

Many studies had been done in order to understand promotion effect and structure/function in unsupported catalyst. Results indicated that d-electrons play an important role promoting catalytical active sites at the edges of MoS2 catalytically structures. Sulfur removal from crude oil, occurs on the edge of molybdenum di-sulfide (MoS2) nano structures, due to promotion of MoS2 nano structures with nickel or cobalt in sulfur-terminated or molybdenum-terminated edge planes. The promotion leads to formation of so-called CoMoS phase (MoS2/Co9S8) first discovered by meaning of Mössbauer spectroscopy, much more CoMoS phase usually called unsupported catalytical particles, have been topic of great interest in …

Study Of Pbdes In Wastewater, Water And Sludge Of El Paso Del Norte Border Region Using Sbse Td/Gc-Ms, Beatriz Adriana Rocha-Gutierrez

Open Access Theses & Dissertations

Polybrominated diphenyl ethers (PBDEs) are a group of brominated compounds widely used as flame retardants. PBDEs are structurally similar to polychlorinated biphenyls (PCBs), and appear to act similarly in the environment. Due to their persistence and lipophilicity, PBDEs are found to be bioaccumulated and biomagnified in the food chain. Current research in PBDEs is focused on their occurrences, concentration, fate and transport in the environment, and the impact in the ecosystem and human health. Since PBDEs are not regulated in the USA, large amounts of these harmful chemicals are being dumped indiscriminately into the drainage system. As a result, these …

Ecological Method Development For Detecting N-Nitrosodimethylamine In Water Using Hplc-Pdad, Jolisa Mcday

Master's Theses and Doctoral Dissertations

Using ethanol, a sustainable reversed-phase high-performance liquid chromatographic method with photo-diode array detection (HPLC-PDAD) was investigated to detect sub-parts per billion concentrations of N-nitrosodimethylamine (NDMA) in drinking water and environmental water samples. This presents a practical and “green” option to analytical methods that require laborious derivatization, expensive detectors and unecological solvents.

Mobile phase characteristics, instrument operating parameters, and sample preparation were investigated. Selectivity for NDMA was evaluated using three different C18 columns. Optimal peak resolution and detection were achieved at 231 nm. The limit of detection and quantitation for NDMA was 0.29 μg/mL and 0.96 μg/mL, respectively, with an ethanol …

Quantification Of Short-Chain Fatty Acids In Cecal Material By Gas Chromatography-Mass Spectrometry, Charles Harrison

Master's Theses and Doctoral Dissertations

Probiotic bacteria in the human colon that produce C₂ – C₄ short chain fatty acids (SCFA) and Lactobacillus species that produce lactate in addition to SCFAs are known to have positive health benefits. These organic acids were extracted with ether from murine cecal material (from Dr. Gary Huffnagle, Univ. of Mich.) and derivatized for quantitative measurement by gas chromatography-mass spectrometry. Antibiotic-treated animals gavaged with Candidaalbicans had a lower level of cecal butyrate relative to untreated animals, but a higher level of butyrate when treated mice were also administered Lactobacillus johnsonii NF-1. More recent studies have demonstrated a butyrate-lowering …

Influence Of The Reducing Agent Triphenylphosphine On Cyclooxygenase-1 Metabolism Of Arachidonic Acid, Rohini Sidhu

Master's Theses and Doctoral Dissertations

Cyclooxygenase (COX) metabolizes the polyunsaturated fatty acid arachidonic acid (AA) to PGG2, a cyclic endoperoxide that also contains a hydroperoxide, which is subsequently reduced to an alcohol in the enzyme to yield PGH2. Reactions catalyzed by COX-1 are significantly influenced by lipid hydroperoxides. The tyrosyl radical that abstracts the 13 pro(s) hydrogen from AA to initiate the COX catalytic cycle is generated by iron-oxo derivatives in the enzyme that result from lipid hydroperoxide interaction with heme iron. Commercial preparations of arachidonic acid (AA) contain lipid hydroperoxides that can be separated from AA by thin layer chromatography and readily reduced to …

Analysis Of The Effect Of Various Ligands On The Hydrolysis Of Ruthenium (Iii) Complexes And Interpretation Of Kinetics Of Hydrolysis Profiles By Uv-Visible Spectrophotometry, Sudheer Koneru

Master's Theses and Doctoral Dissertations

Cancer is one of the major causes of death in the world. Discovery of platinum metal-based drugs like cisplatin and carboplatin have proved to be successful in cancer treatment. Due to subsequent development of resistance, side effects, and fewer toxic effects of these drugs, the usage of these drugs has been limited. Novel drugs were being synthesized utilizing the transition metals like ruthenium, osmium, and copper.

In this research, ruthenium metal complexes of the formula HL[RuCl4L2] (where L= ligand) were synthesized. These ruthenium-based drugs exist in prodrug forms which are activated into antitumor drugs by means of hydrolysis, redox reactions, …

Structure-Activity Relationships Of Pai-1 Inhibitors, Karen Sanders

Master's Theses and Doctoral Dissertations

The inhibition of plasminogen activator inhibitor-1 (PAI-1) is anticipated to increase our understanding of various human ailments with which high levels of PAI-1 have been associated, including diabetes, stroke, and atherosclerosis. Previous accounts have reported the synthesis of inhibitors that bind to PAI-1 with a low affinity, inhibit the serpin plasma protein antithrombin III, and/or fail to inhibit PAI-1 when vitronectin, a cofactor of PAI-1 is present. The synthesis of small-molecule inhibitors of PAI-1 that improve upon these properties has been the main goal of this research. Research efforts focused on examining changes in inhibitor potency based on the manipulation …

Influence Of Metal Nanoparticles On Fluorescence Properties, Vamsi K. Kandimalla

Master's Theses and Doctoral Dissertations

In this project, we studied the effect of silver and gold nanoparticles of various sizes on the fluorescence properties of tris (2, 2-bipyridyl) dichloro ruthenium (II) hexahydrate (Ru (bpy)3 2+), tryptophan and phenylalanine. For (Ru (bpy)3 2+) absorbed on silver and gold nanoparticles, the fluorescence intensity was quenched and showed a significant increase in the fluorescence lifetimes. These quenched intensities were due to energy transfer processes from the donor (Ru (bpy)3 2+) to the metal nanoparticles. Conversely, tryptophan showed enhanced fluorescence intensities with an increase in the size of the nanoparticles, which may be attributed to the effect of fluorescence …

Analytical Chemistry 2.0, David Harvey

Chemistry & Biochemistry Faculty Publications

No abstract provided.

I-Kinetic And Mechanistic Investigations Of Amino Acid Substrates Reactivities With Ferryl Species, Ahmed Ibrahim Youssef Abouelatta

Wayne State University Dissertations

ABSTRACT

I-KINETIC AND MECHANISTIC INVESTIGATIONS OF AMINO ACID SUBSTRATES REACTIVITIES WITH FERRYL SPECIES

II-SYNTHESIS AND CHARACTERIZATION OF DERIVATIVES OF THE BN-TPEN LIGAND AND THEIR METAL COMPLEXES

by

AHMED IBRAHIM YOUSSEF ABOUELATTA

MAY 2011

Advisor: Dr. Jeremy Jacob Kodanko

Major: Chemistry (Organic)

Degree: Doctor of philosophy

The reactivity of tryptophan, methionine, aspartic acid, glutamic acid, histidine and hydrochloride salt of lysine amino acid substrates with the N4Py ferryl species was studied by UV-vis spectroscopy and product characterization. Based on kinetic isotope effect studies and product analysis, an ET-PT mechanism was proposed for the reaction of tryptophan substrate with N4Py ferryl and …

Synthesis Of Analogues Based On The Opioid Alkaloid Mitragynine, Marco A. Arribas

Electronic Theses and Dissertations

Opioid analgesics such as morphine and its derivatives are the most frequently prescribed narcotics for the treatment of severe and chronic pain. Among other side effects caused by the administration of these opioid analgesics, physical dependence and addiction are the most undesirable ones. Currently, pharmacological approaches to treat opioid dependence include mainly methadone and LAAM (mu-agonists), buprenorphine (mu-partial agonist) and clonidine (alpha2-adrenergic agonist). Considering the negative aspects of the relapsing nature correlated to opioid dependence, it is important to search for new ways to overcome this problem. The scope of this work is to study novel compounds based on the …

Development Of Nanotube Hexaniobate For Photocatalytic Production Of Hydrogen From Water, Saroja Pradhan

Open Access Theses & Dissertations

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Conversion Of Racemic Ibuprofen To (S)-Ibuprofen, David Chavez-Flores

Open Access Theses & Dissertations

Ibuprofen is a common Non-Steroidal Anti-Inflammatory Drug (NSAID) sold as a racemic or equal mixture of (R) and (S) mirror-image enantiomers. Without patent protection, ibuprofen is an orphan drug even though one enantiomer, (S)-ibuprofen, provides relief three times faster than its racemic mixture with fewer side effects. The goal of this research was to develop a facile, environmentally benign (no waste of ibuprofen or catalysts), and inexpensive process to convert a commercially available racemic mixture of ibuprofen to the therapeutically active (S)-ibuprofen.

After many attempts, the most successful conversion of racemic ibuprofen to (S)-ibuprofen was the in situ racemization and …

Iron And Manganese Based Nanomaterials For The Removal Of Selenite And Selenate From Aqueous Solution, Christina Marie Gonzalez

Open Access Theses & Dissertations

Selenium, a naturally occurring element in the environment, is an essential nutrient for humans and animals. However, there is a narrow range between selenium deficiency and toxicity. Selenium in natural waters generally has a concentration of < 10 ppb (parts per billion); however, in the San Joaquin Valley of California concentrations of selenium ranging from 140 to 1400 ppb have been observed. Anthropogenic practices such as agricultural irrigation drainage, coal burning power plants, combustion of fossil fuels, and mining operations are increasing selenium concentrations in aqueous environments. Once in aqueous environments, selenium exists primarily as the two inorganic oxoanions selenite (SeO32-) and selenate (SeO42-). Both of these selenium oxoanions are known to bioaccumulate and can cause embryotoxic and teratogenic effects to waterfowl. There has been a variety of treatment technologies developed for remediation of both selenium oxoanions in water including bacterial reduction, membrane filtration, chemical reduction, reverse osmosis, and solar ponds. However, these treatment technologies are not cost efficient. In this study an alternative treatment technique known as adsorption was used with three synthetic nanomaterials consisting of an iron oxide, manganese oxide, and an iron/manganese oxide. The pH profiles, time dependencies, competitive anion effects, and adsorption isotherms were performed with each of the nanomaterials for both selenite and selenate. In addition, X-ray absorption spectroscopy (XAS) studies were performed to determine both the oxidation state and binding coordination of the selenium oxoanion binding to the nanomaterials.

The investigation revealed the non microwave-assisted and microwave-assisted synthetic Fe3O4 and Mn3O4 nanomaterials, as well as the non microwave-assisted synthetic MnFe2O4 nanomaterial had the phases of magnetite, hausmannite, and Jacobsite, while the grain sizes were 27, 25, 25, 34, and 27 nm, respectively. The optimal binding of selenium oxoanions for all nanomaterials examined was reached at pH 4. Both non microwave-assisted and microwave-assisted Fe3O4 …

Chromium(Iii/Vi) Binding To Magnetite (Fe3o4), Hausmannite (Mn3o4), And Jacobsite (Mnfe2o4) Nanomaterials, Jeffrey Edward Hernandez

Open Access Theses & Dissertations

Chromium is a very versatile metal that is used for many applications in the world. Two of the most common ions of chromium that occur naturally are Cr(III) and Cr(VI). These two oxidation states have very different heath effects in living organisms. Cr(III) is relatively non-toxic to living organisms; however, Cr(VI) is very toxic to most living organisms This study was conducted to find a simple and cost effective method to sequester these two common ionic species of chromium from sources of water that are adjacent to or that are affected by other water sources contaminated by these two ions. …