Chemistry Commons^™

Leveraging Propargylic Frameworks In The Total Synthesis Of Natural Products Containing A 2-Aminoimidazole, Ravi P. Singh

Chemistry & Biochemistry Dissertations - Archive

Our group is mainly interested in the total synthesis of marine sponge-derived 2-aminoimidazole-containing alkaloids. A new family of 2-aminoimidazole alkaloids, the Leucetta alkaloids, is a group of >60, 2-aminoimidazole natural products found in marine sponges. Our lab is also interested in the total synthesis of oroidin-based pyrrole-imidazole containing marine sponge-derived alkaloids. These natural products are a growing class of alkaloids with exotic connectivity, unique topologies, and high nitrogen content. The presence of 2-aminoimidazole and pyrrolecarboxamide fragments in their framework represent the signature structural features. Recently, these secondary metabolites have received substantial attention because of their challenging structures and strong biological …

Syhthesis And Optical Properties Of Rare Earth Sulfides And Oxysulfides, Adriana Paola Munoz

Chemistry & Biochemistry Dissertations - Archive

Ternary and quaternary rare earth chalcogenides have gained prominence in recent years, especially because of their wide array of crystal structures and interesting physical properties attributed to the presence of f-electrons 1-3 Among all rare earth chalcogenides, rare earth sulfides of the Ln2S3 family has been explored (Rare earth, Ln) in the industry of pigment, thermoelectric and ceramics, however, the study of their f-electron chemistry and their photoactivity have not been investigated. In this vein, the work described in this dissertation investigates the structures and role of f- electrons in optical properties of the beta and gamma polymorphs of Ln2S3. …

Synthesis Of Modified Polydiacetylene (Pda) Polymers For The Detection Of Infective Species, Shan Hazoor

Chemistry & Biochemistry Theses - Archive

Polydiacetylene (PDAs) polymers are receiving more attention as biosensors due to their ability to change absorption and fluorescence properties upon sensing various chemical and physical changes in the environment. In chapter 1, the introduction to PDA polymers have been described along with their optical properties. Diacetylene (DA) monomers can be synthesized to tune photochemical and sensing properties of PDAs. DAs self-polymerize upon UV-irradiation and show fluorescence upon stimulation. They have been reported as biological and chemical sensors, capable of visible color changes (e.g. blue to red) upon certain environmental factors such as temperature, pH changes, and upon binding with biological …

Radiolysis Of Solid-State Nitrogen Heterocycles Provides Clues To Their Abundance In The Early Solar System, Phillip G. Hammer, Ruiqin Yi, Isao Yoda, H. James Cleaves, Michael P. Callahan

Chemistry and Biochemistry Faculty Publications and Presentations

We studied the radiolysis of a wide variety of N-heterocycles, including many of biological importance, and find that the majority are remarkably stable in the solid-state when subjected to large doses of ionizing gamma radiation from a ⁶⁰Co source. Degradation of N-heterocycles as a function of dose rate and total dose was measured using high performance liquid chromatography with UV detection. Many N-heterocycles show little degradation when γ-irradiated up to a total dose of ~1 MGy, which approximates hundreds of millions of years’ worth of radiation emitted in meteorite parent bodies due to slow radionuclide decay. Extrapolation of …

Synthesis And Biological Studies Of Amphiphilic Compounds Derived From Saccharides And Aminoglycosides, Madher N. Alfindee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Adjacent cells communicate through gap junctions (GJs). These GJs are formed by head to head docking of two hemichannels (HCs) from two adjacent cells. HCs are connexin hexamer proteins. Connexin mutation is the most frequent cause of childhood hearing loss. This hearing impairment affects 2 in every 2000 children. Inhibition of the HCs might be the key factor to treat such disorders. A library of amphiphilic kanamycins was synthesized to be tested as HC inhibitors. These compounds showed excellent inhibition activity in comparison with the parent compound (kanamycin A) with less toxicity.

A library of monosaccharide esters with varying carbon …

Using Novel Spectroscopy Tool To Study Organized Self-Assemblies, Mohammad Rafe M Bin Hatshan

Dissertations

Organized self-assemblies are the cornerstones for countless biological processes and are integral parts of lipids, proteins, carbohydrates, nucleic acids, and cell membranes. Several man-made organized assemblies also play a vital role in interdisciplinary sciences that include micelles, reverse micelles, polymers, polyelectrolytes etc. Weak chemical interactions such as hydrogen bonding, p-p stacking, hydrophilic-hydrophobic and electrostatics often result in interesting organized self-assemblies. Understanding organized self-assemblies provides a huge opportunity to mimic naturally occurring biological macromolecules, design materials and develop strategies for specific applications. Several techniques are routinely used to understand the organized self-assemblies, and optical techniques play an important role in most …

Indole-3-Glycerol Phosphate Synthase Ligand Binding Interactions, Oshane Thomas

Theses, Dissertations and Culminating Projects

Indole-3-glycerol phosphate synthase (IGPS) catalyzes the irreversible ring closure of 1-(ocarboxyphenylamino)- 1-deoxyribulose 5- phosphate (CdRP) into indole-3-glycerol phosphate (IGP) during the fourth step in tryptophan biosynthesis. Analysis of the crystal structure of IGPS from Mycobacterium tuberculosis (MtIGPS) hinted the importance of Lys119 for binding or catalysis. Lys110 from sulfolobus sulfataricus IGPS (ssIGPS) that aligns with Lys119 from MtIGPS, was proposed to be a general acid for the proton transfer that initiates the ring closure and decarboxylation of CdRP. To study the importance of Lys119 in the chemical mechanism for MtIGPS, an amino acid change was made at this position to …

The Effects Of Active Site And Allosteric Residues On Catalysis And Inhibitor Selectivity In The Bacillus Stearothennophilus Dihydrofolate Reductase, Tyler Eck

Theses, Dissertations and Culminating Projects

In drug discovery, building a comprehensive picture of the binding events between a drug and its enzyme target can be useful, especially in the development of new drugs or predicting the effect of a drug on a similar target from the same protein family. It is well known that a drug's selectivity is influenced by its interactions with amino acid residues within the active site, but contributions from residues situated away from (distal to) the active site are less well understood. Using a novel predictive approach PAnPredictor that employs sequence alignments, we have previously predicted residue positions in the dihydrofolate …

Development Of A Ground-Based Aerial-Tracking Instrument For Open-Path Spectroscopy To Monitor Atmospheric Constituents, Haden Hodges

Civil Engineering Undergraduate Honors Theses

A ground-based aerial-tracking instrument, known as the Ground Tracker, designed to provide spectral data to quantify greenhouse gases is under development. The Ground Tracker includes an Optical System including a high power rifle scope, video camera, and spectrometer used to locate an active light source from the Emitter, and collect spectral data by utilizing an actuating mirror. The implementation of this instrument could be made low cost by utilizing existing weather balloon infrastructure to allow the Emitter to be placed into the lower stratosphere. The recovery of the emitter will be possible by tracking the GPS coordinates. Weather balloon instrument …

Speciation Of Aluminum During The Formation Of Aluminum Chlorohydrate: A Combined Kinetic And Mass Spectrometry Study, Mohammad Fakrul Islam

Chemistry & Biochemistry Dissertations - Archive

Speciation of Aluminum During the Formation of Aluminum Chlorohydrate: A Combined Kinetic and Mass Spectrometry Study Mohammad Fakrul Islam, Ph.D. The University of Texas at Arlington, 2019 Supervising Professor: Frederick M. MacDonnell Aluminum chlorohydrate (ACH) is synthesized in a heterogeneous reaction of aluminum ingots or pellets with aqueous hydrochloric acid. This exothermic reaction produces copious amounts of hydrogen gas and ultimately generates product grade aluminum chlorohydrate when the specific gravity of the solution reaches 1.33-1.35. Other product specifications include 3.5-4.0 pH, 7.9-8.4 wt.% chloride, 23-24 wt.% Al2O3, low turbidity (<50 NTU) and high basicity (>83%). A relative study of aluminum ingot with pellet shows …

Synthesis And Characterization Of Porous And Dense Silicon Oxycarbide (Sico) Materials, Susana Isabel Aguirre-Medel

Chemistry & Biochemistry Dissertations - Archive

In the field of materials discovery, the appearance of Polymer Derived Ceramics (PDC’s) over 30 years ago represents a breakthrough in materials science and development. The PDC route represents significant advantages in ceramic science and technology. This route enables synthesis of bulk ceramics, fibers, porous ceramics and coating materials that are stable at temperatures up to 2000 oC. PDCs can be separated into binary and ternary systems. Examples of binary systems are silicon carbide (SiC) and silicon nitride (Si3N4 ). Ternary systems include silicon carbonitride (SiCN) and silicon oxycarbide (SiCO). One very important feature of PDCs is their crystallization resistance. …

Improved Sample Preparation Method For Lc-Ms/Ms Based Cellular Proteomics And Co-Immunoprecipitation Cross-Linking Proteomics Study Of Toll-Like Receptor 4, A.D.A Shahinuzzaman

Chemistry & Biochemistry Dissertations - Archive

Mass spectrometry-based methods are now widely practiced in large-scale proteomics studies. Unfortunately, sample loss in proteomics hinders complex analysis in proteomics, and immune precipitation (IP) mass spectrometry-based proteomics is getting popular in studying comprehensive signaling pathways. To contribute to these demanding research areas, I have completed two experimental projects in this thesis. In our first project, we developed a sample preparation method to identify proteins from detergent-containing cell lysate samples efficiently. Methanol-chloroform purification is an essential step in LC-MS/MS based cellular proteomics experiments since it removes salts and detergents from the sample. The cell lysis buffer contains a high concentration …

Analytical Methods For Solving Complex Problems In Food And Environmental Science, Jamie Lynn York

Chemistry & Biochemistry Dissertations - Archive

Complex samples can be challenging for analysis in a number of different ways. Food and environmental samples can be particularly difficult due to their non-uniformity from sample to sample, possible unknown contents, and complexity in terms of their number of constituents and range of abundances of different species. To overcome challenges faced with the analysis of complex samples, intricate sample handling and processing techniques need to be tailored in order to build optimal methods. These procedures can include sample preparation techniques, on-line sample clean-up, and/or tools that the instrument has to offer. Each complex sample needs to be assessed for …

Liquid Flow Measurement: From Inline Hydrocephalus Shunt Flow Monitor To Flowmetry In The Nanoliter/Minute Scale, Chuchu Qin

Chemistry & Biochemistry Dissertations - Archive

This dissertation primarily focuses on designing and developing novel sensing strategies and instruments for ultra-low liquid flow measurement. An inline thermal flow sensor based on a single common thermistor has been developed to quantitatively measures cerebral spinal fluid flow rate in hydrocephalus shunt. The technique facilitates the diagnosis of shunt failure due to blockage or over-drainage. This allows timely remediation of shunt-flow malfunctions, thereby avoiding severe complications that can arise. The thermal flow sensor utilizes the bidirectional ability of the thermistor to both heat the surrounding and to sense the temperature. The net temperature change from immediately before and after …

A Foundational Study Of A New Synthetic Method Of Metal Carbonyl Clusters, Miles Shaun Millard

Boise State University Theses and Dissertations

“Traditional” Metal Carbonyl Clusters (MCCs) contain a framework of multiple metal atoms bound together through formal metal-metal (M-M) bonds. Current methods of synthesis result in different cluster sizes and lack a method to control growth. This project proposes a new method of MCC synthesis to build larger structures utilizing secondary non-covalent interactions to develop “non-traditional” MCCs. The N,N’-diarylurea moiety is a strong hydrogen bond donor/acceptor that can induce self-assembly into larger secondary structures. The union of metal carbonyl and urea chemistry provides a potential method of “non-traditional” MCC synthesis. This proof of concept experiment will elucidate foundational information such …

Investigating Soluble Organic Compounds In Aqueously Altered Carbonaceous Chondrites By Ultrahigh Resolution Orbitrap Mass Spectrometry, Patrick Kyle Schwartz

Boise State University Theses and Dissertations

Most meteorites are fragments from main-belt asteroids and contain extremely primitive materials that have preserved a compositional record of the early Solar System. After the formation of their parent bodies, carbonaceous chondrites experienced secondary modification from thermal metamorphism and/or aqueous alteration. Secondary processing likely influenced the synthesis and/or final composition of organic compounds in parent bodies; thus, these effects may be elucidated from the study of different meteorites. Although the role of aqueous alteration has been investigated for a few specific classes of compounds (such as amino acids), the effect of aqueous alteration on the full inventory of organic compounds …

Computational Study Of The Ro-Vibrational Spectrum Of Co-Co₂, Eduardo Castro-Juarez, Xiao-Gang Wang, Tucker Carrington Jr., Ernesto Quintas-Sánchez, Richard Dawes

Chemistry Faculty Research & Creative Works

An accurate ab initio ground-state intermolecular potential energy surface (PES) was determined for the CO-CO₂ van der Waals dimer. The Lanczos algorithm was used to compute rovibrational energies on this PES. For both the C-in and O-in T-shaped isomers, the fundamental transition frequencies agree well with previous experimental results. We confirm that the in-plane states previously observed are geared states. In addition, we have computed and assigned many other vibrational states. The rotational constants we determine from J = 1 energy levels agree well with their experimental counterparts. Planar and out-of-plane cuts of some of the wavefunctions we compute …

Enhanced Flocculation Using Drinking Water Treatment Plant Sedimentation Residual Solids, Sandhya Rao Poleneni, Enos Inniss, Honglan Shi, John Yang, Bin Hua, Joseph Clamp

Chemistry Faculty Research & Creative Works

Inefficient removal of total organic carbon (TOC) leads to the formation of carcinogenic disinfection by-products (DBPs) when a disinfectant is added. This study is performed in an effort to develop a simple, non-invasive, and cost-effective technology that will effectively lower organic precursors by having water utilities reuse their treatment residual solids. Jar tests are used to simulate drinking water treatment processes with coagulants-aluminum sulfate (alum), poly-aluminum chloride (PACl), and ferric chloride and their residual solids. Ten coagulant-to-residual (C/R) ratios are tested with water from the Missouri River at Coopers Landing in Columbia, MO versus alluvial ground waters. This treatment results …

Structural Characterization Of A Prolyl Aminodipeptidase (Pepx) From Lactobacillus Helveticus, Deanna Dahlke Ojennus

Chemistry Faculty Scholarship

Prolyl aminodipeptidase (PepX) is an enzyme that hydrolyzes peptide bonds from the N-terminus of substrates when the penultimate amino-acid residue is a proline. Prolyl peptidases are of particular interest owing to their ability to hydrolyze food allergens that contain a high percentage of proline residues. PepX from Lactobacillus helveticus was cloned and expressed in Escherichia coli as an N-terminally His-tagged recombinant construct and was crystallized by hanging-drop vapor diffusion in a phosphate buffer using PEG 3350 as a precipitant. The structure was determined at 2.0 Å resolution by molecular replacement using the structure of PepX from Lactococcus lactis (PDB entry …

Andrews University Chemistry Lecture Series, Desmond Murray

Andrews Agenda: Campus News

No abstract provided.

Removal Of As (Iii) And As (V) From Potable Water Using Zno Nanoparticles, Grecia Torreblanca Baez

Theses and Dissertations

Heavy metal and toxic element contamination of the environment has been increasing with increasing industrialization. Arsenic has become an element of particular concern because of its toxicity, which is oxidation state dependent. As(III) is observed to be much more toxic than As(V), as well the removal is more difficult than As(V) in traditional water treatment technology. In the present study, As (III) and As(V) removal was investigated using a zinc oxide nanomaterial that was synthesized using a titration/precipitation technique, and characterized using powder x-ray diffraction. In the present study, the kinetics of adsorption, the adsorption isotherms as well as the …

Monitoring Tropospheric Gases With Small Unmanned Aerial Systems (Suas) During The Second Cloudmap Flight Campaign, Travis J. Schuyler, Sean C. C. Bailey, Marcelo I. Guzman

Chemistry Faculty Publications

Small unmanned aerial systems (sUAS) are a promising technology for atmospheric monitoring of trace atmospheric gases. While sUAS can be navigated to provide information with higher spatiotemporal resolution than tethered balloons, they can also bridge the gap between the regions of the atmospheric boundary layer (ABL) sampled by ground stations and manned aircraft. Additionally, sUAS can be effectively employed in the petroleum industry, e.g., to constrain leaking regions of hydrocarbons from long gasoducts. Herein, sUAS are demonstrated to be a valuable technology for studying the concentration of important trace tropospheric gases in the ABL. The successful detection and quantification of …

Computational Studies Of Thermal Properties And Desalination Performance Of Low-Dimensional Materials, Yang Hong

Department of Chemistry: Dissertations, Theses, and Student Research

During the last 30 years, microelectronic devices have been continuously designed and developed with smaller size and yet more functionalities. Today, hundreds of millions of transistors and complementary metal-oxide-semiconductor cells can be designed and integrated on a single microchip through 3D packaging and chip stacking technology. A large amount of heat will be generated in a limited space during the operation of microchips. Moreover, there is a high possibility of hot spots due to non-uniform integrated circuit design patterns as some core parts of a microchip work harder than other memory parts. This issue becomes acute as stacked microchips get …

Quantum Chemical Calculations Applied To Somo–Homo Conversion And Vibrationally Averaged Nmr Shielding Parameters, Erik Johnson

Department of Chemistry: Dissertations, Theses, and Student Research

The inversion of frontier orbitals of free radicals was studied using density functional theory calculations in Gaussian 09. Comparisons of images of orbitals in GaussView was used to assess the relative positions of singly occupied and doubly occupied orbitals and to determine which was the highest in energy. A variety of organic free radicals were studied including several radical anions and also a neutral radical. It was found that cross-conjugation appears to be a factor in whether or not molecules show SOMO-HOMO conversion. Cross-conjugation is when two unsaturated groups are conjugated to a third unsaturated group but are not conjugated …

Design And Synthesis Of Stable Aminyl And Nitroxide Radical Precursors, Joshua Bryan Lovell

Department of Chemistry: Dissertations, Theses, and Student Research

Aminyl diradicals with sterically-hindered tert-butyl groups have yet to be fully investigated for their increased stability due to their difficulty in synthesis. The first chapter of this thesis details design and synthesis towards sterically-hindered aminyl radical and diradical precursors.

Structural features effecting nitroxide radical stability have been well investigated except for the impact on the ring-size of stability of nitroxides towards reduction by ascorbate. Two 7-membered nitroxides derived from TEMPONE and TEMPOL have been synthesized and characterized. The alcohol nitroxide shows increased stability towards reduction by ascorbate compared to the corresponding TEMPOL, while the other nitroxide shows decreased stability compared …

The Investigation Of Secondary Particle Formation Initiated By Non-Prototypical Sources And The Role Of Amines In The Atmosphere, Emily Burrell

Theses and Dissertations

This dissertation is a collection of works that investigate non-prototypical sources leading to new particle formation in the atmosphere. Particles play a major role in atmospheric chemistry. For example, particles are a component of smog and are commonly found in high concentrations under conditions of atmospheric inversions. In order to reconcile the difference between measured and modeled particle concentrations new mechanisms from non-prototypical sources for particle formation need to be determined. Formation of particles has frequently been modeled using classical nucleation theory (CNT). The first step in CNT is the nucleation step where molecular clusters form. In a second step, …

Preparation, Functionalization, And/Or Characterization By X-Ray Photoelectron Spectroscopy Of Carbon Surfaces For Biosensors And Other Materials, Varun Jain

Theses and Dissertations

My dissertation is primarily divided into two parts. The first deals with the preparation, functionalization, and characterization of carbon surfaces prepared by direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS) as substrates for bioarrays. Part two discusses applications of XPS peak fitting in surface chemical analysis. Chapter 1, the introduction, includes (i) a discussion of the construction of bioarrays and the preparation of sputtered surfaces, e.g., by DCMS and HiPIMS, and also functionalization (bioconjugate) chemistry with special emphasis on the importance of covalent functionalization of surfaces, and (ii) a discussion of the surface characterization techniques and …

Amyloidogenicity Of Naturally Occurring Full-Length Animal Iapp Variants, Larry M. Palato, Shannon Pilcher, Alissa Oakes, Arleen Lamba, Jaris Torres, Litza I. Ledesma Monjaraz, Crystabel Munoz, Edward Njoo, Dillon J. Rinauro, Kate Alexandra Menefee, Angela Tun, Betssy L. Jauregui, Sarah Shapiro, Olivia H. Nossiff, Eileen Olivares, Kevin Chang, Viviane Nguyen, Luiza A. Nogaj, David A. Moffet

Chemistry and Biochemistry Faculty Works

Aim: To identify naturally occurring variants of IAPP capable of inhibiting the aggregation of human IAPP and protecting living cells from the toxic effects of human IAPP. Background: The loss of insulin-producing β-cells and the overall progression of type 2 diabetes appears to be linked to the formation of toxic human IAPP (hIAPP, Islet Amyloid Polypeptide, amylin) amyloid in the pancreas. Inhibiting the initial aggregation of hIAPP has the potential to slow, if not stop entirely, the loss of β-cells and halt the progression of the disease. Objective: To identify and characterize naturally occurring variants of IAPP capable of inhibiting …

Synthesis, Characterization And Biological Evaluation Of Novel (S,E)-11-[2-(Arylmethylene) Hydrazono] Pyrrolo [2,1-C] [1,4] Benzodiazepine Derivatives, David Mingle

Electronic Theses and Dissertations

Pyrrolo [2,1-c] [1,4] benzodiazepine (PBD) is a class of natural products obtained from various actinomycetes which have both anti-tumor and antibiotic activities and can bind to specific sequences of DNA. PBD-dilactam was initially produced using isatoic anhydride and (L)-proline which was then converted to the PBD-thiolactam using Lawesson's reagent. Reaction of thiolactam with hydrazine in ethanol afforded PBD-11-hydrazinyl. Condensation of 11-hydrazinyl PBD with aldehydes possessing various substitutions was performed to obtain (S,E)-11-[2-(arylmethylene) hydrazono] pyrrolo [2,1-c] [1,4] benzodiazepine derivatives. ¹HNMR, ¹³C-NMR, DEPT, IR, GC-MS and X-ray crystallography were used for the characterization. Inhibition activity of the products …

Electrodeposition Of Hydrogen Molybdenum Bronze Films And Electrochemical Reduction Of Carbon Dioxide At Low Over Potentials, Sami Alharbi

Electronic Theses and Dissertations

Hydrogen molybdenum oxide, known has molybdenum bronze, is a material of interest due to catalyzing electron transfer reactions. Specifically, molybdenum bronze is an electrocatalyst toward carbon dioxide reduction. Electrochemical deposition from a peroxymolybdic acid solution is a method for preparing molybdenum bronze films. This work demonstrates reproducible electrodeposition on indium tin oxide substrates and conductive carbon paper. Film thickness depends on concentration, time and pH. After characterization by film thickness, resistance, XRD and XPS, the as deposited films served as the working electrode for electrochemical reduction of carbon dioxide in 0.1 M NaHCO₃. Ion chromatography determined formate resulting …