Digital Commons Network^™

Synthesis Of A Model Of The Bc Ring System Of Oxygenated Angucyclines, Xiaolan Wu, Abdullah Allaoa, Tony E. Nicolas

Publications and Research

Angucycline is a subclass of natural antibiotics, containing a characteristic tetracyclic ring structure, and featuring a wide range of biological functions, including antitumor, antiviral and antifungal properties. This extraordinarily therapeutic character has interested many chemists to develop efficient methodologies for synthesizing the tetracyclic ring system of angucycline. Construction of the BC ring configuration appears as a synthetic challenge. Successful installation of hydroxyl groups at the AB junction would pave the way for efficient syntheses. As a continuation of the previous work done on this system, our synthetic methodology focuses on the coupling of a suitably substituted Phthalide and an activated …

Prep-Hplc Method Development To Isolate Potentially-Carcinogenic, Arginine-Based Heterocyclic Amines, Victoria S. Kim

Honors Theses

Heterocyclic amines (HCAs) are carcinogenic molecules generated from the reaction of creatin(in)e and amino acids at high cooking temperatures in meat. Previous research has shown that replacing creatine with arginine leads to new, uncharacterized HCA molecules. This research entails implementing and optimizing the preparative HPLC analysis of extracts from multiple burnings of arginine with phenylalanine. Isolated fractions from the prep-HPLC analysis were further analyzed using the Ames test to identify mutagenic compounds. Prep-HPLC provides quality control to the burning process along with isolation of larger quantities of materials for further characterization and molecular structure identification.

Process For Detection Of Alzheimer's Disease From A Serum Sample, Mark A. Lovell, Bert C. Lynn

Chemistry Faculty Patents

Disclosed is a method of detecting a concentration of a biomarker in a human subject having or being at risk of developing Alzheimer's disease or Mild Cognitive Impairment (MCI). Also disclosed is a process for detecting a concentration of a biomarker in a human subject having or being at risk of developing Alzheimer's disease or Mild Cognitive Impairment (MCI) comprising (a) detecting a first concentration of lipocalin-PDS/TTR complex in a blood sample or urine sample from the subject, (b) determining a second concentration of PDS/TTR complex in a blood sample or urine sample from an unaffected individual, and ( c) …

Investigation Of Aerosol Optical And Chemical Properties Using Humidity Controlled Cavity Ring-Down Spectroscopy, Xijing Zhu

Dissertations and Theses

Scientists have been observing a change in the climate since the beginning of the 20^th century that cannot be attributed to any of the natural influences of the past. Natural and anthropogenic substances and processes perturb the Earth's energy budget, contributing to climate change. In particular, aerosols (particles suspended in air) have long been recognized to be important in processes throughout the atmosphere that affect climate. They directly influence the radiative balance of the Earth's atmosphere, affect cloud formation and properties, and are also key air pollutants that contribute to a variety of respiratory and cardiovascular diseases. Despite their …

Endothelial Nitric Oxide Synthase Oxygenase On Lipid Nanodiscs: A Nano-Assembly Reflecting Native-Like Function Of Enos, Ghaith Altawallbeh, Mohammad M. Haque, Kiril A. Streletzky, Dennis J. Stuehr, Mekki Bayachou

Physics Faculty Publications

© 2017 Elsevier Inc. Endothelial nitric oxide synthase (eNOS) is a membrane-anchored enzyme. To highlight the potential role and effect of membrane phospholipids on the structure and activity of eNOS, we have incorporated the recombinant oxygenase subunit of eNOS into lipid nanodiscs. Two different size distribution modes were detected by multi-angle dynamic light scattering both for empty nanodiscs, and nanodiscs-bound eNOSoxy. The calculated hydrodynamic diameter for mode 1 species was 9.0 nm for empty nanodiscs and 9.8 nm for nanodisc bound eNOSoxy. Spectroscopic Griess assay was used to measure the enzymatic activity. Remarkably, the specific activity of nanodisc-bound eNOSoxy is …

Pretargeting Of Internalizing Trastuzumab And Cetuximab With A 18f-Tetrazine Tracer In Xenograft Models, Outi Keinänen, Kimberly Fung, Jacob Pourat, Vilma Jallinoja, Delphine Vivier, Nagavara Kishore Pillarsetty, Anu J. Airaksinen, Jason S. Lewis, Brian M. Zeglis, Mirkka Sarparanta

Publications and Research

Background: Pretargeting-based approaches are being investigated for radioimmunoimaging and therapy applications to reduce the effective radiation burden to the patient. To date, only a few studies have used short-lived radioisotopes for pretargeting of antibodies, and such examples with internalizing antibodies are even rarer. Herein, we have investigated pretargeting methodology using inverse electron-demand Diels-Alder (IEDDA) for tracing two clinically relevant, internalizing monoclonal antibodies, cetuximab and trastuzumab.

Results: Bioorthogonal reaction between tetrazine and trans-cyclooctene (TCO) was used for tracing cetuximab and trastuzumab in vivo with a fluorine-18 (t½ = 109.8 min) labelled tracer. TCO-cetuximab or TCO-trastuzumab was administered 24, 48, or 72 …

Enantioselective Synthesis Of An Anticancer Ruthenium Polypyridyl Complex (Rpc) And Influence Of Chiral Selectivity On Dna Photocleavage, Shomita Ferdous

Chemistry & Biochemistry Theses - Archive

Ruthenium polypyridyl complexes (RPCs) represent a promising therapeiutic class of drugs for transition-metal based anticancer drug development. The complex [(phen)2Ru(tatpp)Ru(phen)2] (44+) is a RPC which has shown success in both cell free and cellular assay. Unlike many other RPCs, 44+ can selectively kill malignant cells without light irradiation from external sources. This binuclear complex 44+ is a DNA intercalator containing redox-active ligand tatpp (9,11,20,22-Tetraaza tetrapyrido[3,2-a:2'3'-c:3'',2''- 1:2''',3''']-pentacene) which cleaves DNA in presence of a mild reducing agent, i.e. glutathione (GSH).1,2,3 The cellular assay (MTT assay) with different types of malignant cells has also established this as an equally potent cytotoxic agent …

Synthetic And Mechanistic Investigations Of Ruthenium Alkylidene-Catalyzed Alkene-Silane Cross-Coupling Reactions, Apparao Bokka

Chemistry & Biochemistry Dissertations - Archive

Grubbs-type ruthenium alkylidene-catalyzed intramolecular alkene hydrosilylation and intermolecular dehydrogenative silylation and hydrosilylation of vinylarenes have been achieved with high regio- and stereoselectivity. Mechanistic details to support the initial activation of ruthenium complex have been revealed. Chapter 1 describes the uses of organosilanes in various fields. Development of transition metal-catalyzed hydrosilylations, alkene/alkyne metathesis activities of Grubbs-type ruthenium alkylidenes and non-metathetical activities including hydrosilylation of alkynes are discussed. The development of intramolecular hydrosilylation of alkenylsilyl ethers through reaction discovery and optimization is discussed. The strategy developed has been tested successfully on a variety of substrates with varying steric and electronic properties. A …

Development Of Qualitative And Quantitative Applications In Energy Industry Using Gas Chromatography- Vacuum Ultraviolet Spectroscopy, Ling Bai

Chemistry & Biochemistry Dissertations - Archive

Characterization and evaluation of hydrocarbon assets, including content of linear and branched alkanes, cycloalkanes, aromatics, olefins, and naphthenes, among others, during production and distribution are very crucial in oil and gas industries. Quantification and qualification of bulk composition of hydrocarbon groups in complex samples like gasoline, diesel, and other high value refinery products is very challenging. Gas chromatography (GC) is the most popular technique among the petrochemical industry and many of the EPA and ASTM methods have been established based on GC for analyzing hydrocarbons in complex mixtures. Though there are many methods available, there are still limitations on the …

Vibronically Coherent Ultrafast Triplet-Pair Formation And Subsequent Thermally Activated Dissociation Control Efficient Endothermic Singlet Fission, Hannah L. Stern, Alexandre Cheminal, Shane R. Yost, Katharina Broch, Sam L. Bayliss, Kai Chen, Maxim Tabachnyk, Karl J. Thorley, Neil Greenham, Justin Hodgkiss, John E. Anthony, Martin Head-Gordon, Andrew J. Musser, Akshay Rao, Richard H. Friend

Chemistry Faculty Publications

Singlet exciton fission (SF), the conversion of one spin-singlet exciton (S₁) into two spin-triplet excitons (T₁), could provide a means to overcome the Shockley–Queisser limit in photovoltaics. SF as measured by the decay of S₁ has been shown to occur efficiently and independently of temperature, even when the energy of S₁ is as much as 200 meV less than that of 2T₁. Here we study films of triisopropylsilyltetracene using transient optical spectroscopy and show that the triplet pair state (TT), which has been proposed to mediate singlet fission, forms on ultrafast timescales …

Identification Of Proteolytic Cleavage And Arginine Modifications By Chemical Labeling And Mass Spectrometry, Maheshika S.K. Wanigasekara

Chemistry & Biochemistry Dissertations - Archive

Post-translational modification of proteins plays a significant role in the regulation of cellular processes. During the translation, process proteins undergo different modifications, which are known as post-translational modifications (PTMs). Due to their low abundances, PTM analysis presents several challenges; therefore, efficient and sensitive PTM detection methods are required. Arginine is an essential amino acid in a cell, which undergoes several kinds of PTMs. Finding these functional arginine residues in a protein is a challenging task. The task was successfully addressed, and the findings are not only reported herein, but an assessment was recently reported covering the new chemical labeling methods …

Green Chemistry Oxidative Modification Of Peptoids Utilizing Bleach And Tempo, Jesse Leland Roberts

Graduate Theses and Dissertations

Biotherapeutic drugs, derived from biological molecules such as proteins and DNA, are becoming an integral and exceptionally critical aspect of modern medicine. Compared to common pharmaceutical drugs, biotherapeutics are much larger in size and have greater target specificity, allowing them to treat many chronic diseases ranging from cancer to rheumatoid arthritis. The major issue with protein based therapeutics is that they readily undergo proteolysis, or enzymatic degradation, when administered through subcutaneous injections. Traditionally, biotherapeutic modification procedures have centered on the use of PEG derivatives. This process, called PEGylation, is unfavorable due to the increases in molecular weights of the proteins …

Chemoselective Reagents For Derivatization Of Trace--Level Volatile Carbonyl Compounds Using A Microreactor Approach., Mumiye A. Ogunwale

Electronic Theses and Dissertations

Detection and analysis of trace level volatile aldehydes and ketones has become a significant research frontier because of the applicability for environmental monitoring and assessment, noninvasive diseases diagnosis, and in food safety assessment for the US Food and Drug Administration. The number of derivatization reagents for detection of aldehydes and ketones has increased considerably over the last decade. However, the majority of these derivatization reagents are not efficient in derivatizing unsaturated carbonyl compounds due to the presence of electron withdrawing groups adjacent to the reactive functional moieties making them insufficiently nucleophilic. The analysis of trace-level carbonyl compounds challenges existing analytical …

Molecular Geometries And Other Properties Of H2o⋯Agi And H3n⋯Agi As Characterised By Rotational Spectroscopy And Ab Initio Calculations, Chris Medcraft, Eva Gougoula, Dror M. Bittner, John C. Mullaney, Susana Blanco, David P. Tew, Nicholas R. Walker, Anthony C. Legon

Chemistry & Biochemistry Faculty Publications

The rotational spectra of H₃N⋯AgI and H₂O⋯AgI have been recorded between 6.5 and 18.5 GHz by chirped-pulse Fourier-transform microwave spectroscopy. The complexes were generated through laser vaporisation of a solid target of silver or silver iodide in the presence of an argon gas pulse containing a low concentration of the Lewis base. The gaseous sample subsequently undergoes supersonic expansion which results in cooling of rotational and vibrational motions such that weakly bound complexes can form within the expanding gas jet. Spectroscopic parameters have been determined for eight isotopologues of H₃N⋯AgI and six isotopologues of …

Applying The Diffusion Of Innovation Theory To Characterize Stem Faculty Attending Professional Development Programs, Dihua Xue

Department of Chemistry: Dissertations, Theses, and Student Research

Instructional practices in undergraduate STEM courses have been static for decades, with a primary focus on lecture. Over the last twenty years, extensive research on how people learn science has led to the development of innovative instructional strategies that have been shown to enhance students’ learning and interest. These in turn have led to calls to reform instructional practices in STEM fields at the undergraduate level. However, evidence shows that these research-based instructional strategies have largely not been incorporated into classes. The promotion of these new strategies has been mostly conducted through workshops. Although numerous studies have evaluated the impact …

Developing Functionalized Peroxide Precursors For The Synthesis Of Cyclic And Spirocyclic Ethers, Anna J. Diepenbrock

Department of Chemistry: Dissertations, Theses, and Student Research

There is increasing interest in the development of methods for the synthesis of oxetanes and spirocyclic oxetanes, a class of molecules of interest to chemists as they synthesize libraries of possible drug target scaffolds with tunable physiochemical and biological properties.^1,2 Although most ethers are prepared through reaction of nucleophilic oxygen with electrophilic carbon, this work explores new reagents and routes for the synthesis of spirocyclic oxetanes based upon an application of "umpolung" or polarity reversal involving attack of nucleophilic carbon on the electrophilic oxygen of a peroxide (Scheme 1). In this work, a 2-carbon peroxide synthon for reverse etherification …

Eigenstate–Specific Temperatures In Two–Level Paramagnetic Spin Lattices, Mark Masthay, Calley N. Eads, Amber N. Johnson, R. Gerald Keil, Phillip Miller, Ross E. Jones, Joe D. Mashburn, Harry B. Fannin

Chemistry Faculty Publications

Increasing interest in the thermodynamics of small and/or isolated systems, in combination with recent observations of negative temperatures of atoms in ultracold optical lattices, has stimulated the need for estimating the conventional, canonical temperature Tconvc of systems in equilibrium with heat baths using eigenstate-specific temperatures (ESTs). Four distinct ESTs—continuous canonical, discrete canonical, continuous microcanonical, and discrete microcanonical—are accordingly derived for two-level paramagnetic spin lattices (PSLs) in external magnetic fields. At large N, the four ESTs are intensive, equal to Tconvc, and obey all four laws of thermodynamics. In contrast, for N < 1000, the ESTs of most PSL eigenstates are non-intensive, differ from Tconvc, and violate each of the thermodynamic laws. Hence, in spite of their similarities to Tconvc at large N, the ESTs …

Determination And Quantification Of Lead Content In Mammut Americanus Dentine Material By Anodic Stripping Voltammetry, Emma R. Shipley

Mastodon Tusk Project Posters

A 120,000-200,000 year old mastodon tusk of species Mammut americanus, recovered from Hampton, Iowa in 1933 (right) was tested for lead using a lead test from Home Depot.1 The lead test was returned positive, so Anodic Stripping Voltammetry (ASV) was undertaken to determine the concentration of lead in the dentine material of the tusk. The lead concentration is of interest because lead could affect both the health of the conservator and researchers and also inform about the diet of the mastodon. Tusk dentine material (left) functions similarly to human teeth, and studies have shown that 90% of lead in the …

Sem/Edx Chemical Composition Map Of Mastodon Tusk, Juliana Herran

Mastodon Tusk Project Posters

The goal of this project was to study one of the rarest objects in the collection of the UNI museum dating to the Aftonian or Yarmouth age (around 120,000 to 200,000 years old).

The tusk is 11 feet, 7.5 inches with a circumference at the proximal end of 2 feet, 2 inches.

There have been previous attempts of restoration of this tusk but there are not specific procedures on record that specify the materials or methods used during the restoration attempts with sufficient detail.

With the support of the Carver Grant awarded to the UNI museum, research teams containing students …

Developmental Steroids And Vitamins: Identified And Quantified In Predatory Lady Beetles, Andrea Hixson

Honors Theses

Autumn brings ladybeetles into homes to seek shelter during the winter, which is a nuisance. Their bites may induce an allergic reaction resulting in painful rashes. Predatory ladybeetles have been used as a biological control agents. Not only do they feed on ecological pests, they also feed on the saps of ripe fruits reducing the value of the damaged crop. Two species of ladybeetles (Coleoptera: Coccinellidae) will be examined to determine the quantities of steroids and vitamins used throughout their life stages. The species examined are native, Hippodamia convergens, of North America, and an invasive, Harmonia axyridis, of Asia. The …

Evaluating Ligand Assisted Activation Of Small Molecules Through Proton Reduction And Alcohol Oxidation., Rahul Jain

Electronic Theses and Dissertations

Hydrogen is a potential alternate to the carbon fuels to meet the future demands for energy in an eco-friendly manner. Hydrogen produced by the electrolysis of water is stored in fuel cells which on demand can be converted into electrical energy upon the reaction with oxygen. In the quest for economically viable electrocatalysts for hydrogen evolution, the work in this dissertation describes evaluation of nickel based catalysts coordinated to redox active ligands, dialkyl/diarylphosphine benzenethiol and bis(thiosemicarbazone) for their ability to generate hydrogen with external acids as a proton source. A nickel complex with the benzenethiol ligand framework follows a traditional …

Interaction Between Fragments Of Tau Protein Investigated By Force Spectroscopy Using Afm, Anad Mohamed Afhaima

Theses and Dissertations

Over the last couple of decades, there has been rapidly growing interest in research of natively unfolded proteins. Some proteins from this group are implicated in a number of neurodegenerative diseases. One group of neurodegenerative diseases, taupathies, is associated with tau protein. A number of biophysical and spectroscopic studies have revealed that tau protein can expand to a largely extended state and to transition rapidly between many different conformations. Although many of the techniques that elucidate structure of macromolecules have provided important information about the folded states of proteins, important information about the transition between the extended conformation states remain …

Electrophilic Cleavage And Functionalization Of Polyisobutylenes Bearing Unsaturations In The Backbone And Synthesis Of Polymers For This Process, Christopher Campbell

Dissertations

In the first project, we demonstrated a new reaction, which is a subset of the Friedel‑Crafts alkylation reaction, in which the alkylating carbocation undergoes a cleavage reaction prior to reaction with the aromatic substrate. This reaction was discovered by the observation that when a PIB containing a large amount of coupled fraction was subjected to a mixture of protic and Lewis acids (HCl/TiCl₄) in the presence of an alkoxybenzene compound, the coupled fraction was quantitatively converted to its constituent monofunctional chains, which became functionalized by the alkoxybenzene.

In the second project, a commercial polymer, poly(isobutylene-co-isoprene) (butyl …

Oxidation Of Dibenzothiophene To Dibenzothiophene-Sufone Using A Molybdenum (Vi) Oxide Catalyst: A Kinetic Study Testing Solvent Dependency And Mole Ratio Efficiency, Tomas Trevino Jr.

Theses and Dissertations

Oxidative desulfurization (ODS) is currently a solution to hydrodesulphurization. Currently, industrial usage of hydrodesulphurization (HDS) is the common source for petroleum purification. Unfortunately, HDS comes with environmental and economical ramifications. Due to the problems and potential hazards being presented with HDS, ODS has become a topic of interest in research development. A kinetic study using molybdenum (VI) oxide as a catalyst was used in oxidative desulfurization. Factors such as mole ratio and solvent dependency were tested for efficiency. As activation energy was calculated to show maximum efficiency with respect to temperature and concentration. Gas Chromatography, FT-IR, and Mass Spectroscopy were …

Remediation Of Lead And Copper Ions From Water Solutions Using Transition Metal Sulfides, Jesus M. Cantu Jr.

Theses and Dissertations

Heavy metal contamination in water solutions has been a major concern since many transition metals don’t play a role in any biological function and are actually detrimental to human health. There have been several techniques that have been implemented for the remediation of heavy metal contaminants. For this project, three metal sulfides—Fe7S8, ZnS, TiS 2—were synthesized and studied for their capabilities to remove Pb(II) and Cu(II) from water solutions. Several parameters were investigated to determine the effects of pH, time, temperature, binding capacities, and interfering ions. The room temperature adsorption capacities ranged 6.23–333.3 mg/g for Pb(II) and 1.31–250 mg/g for …

Synthesis Of Tetraethyl ((2-Amino-1,4-Phenylene)Bis(Methylene)) Bis(Phosphonate): An Intermediate In The Synthesis Of Amino-Substituted Conjugated Materials, Ariel Ivan Torres Burgueno

Theses and Dissertations

Discussed here are the syntheses of the phosphonate precursors for the Wittig-Horner synthesis of poly-phenylene vinylene (PPV) and distyrylbenzene (DSB) derivatives and their respective distyrylbenzene analogs containing amino moieties. The synthesis of the different compounds was achieved through bromination, Michaelis-Arbuzov reaction, reduction of the nitro group with a commercial cobalt sulfide catalyst and sodium borohydride. Preliminary evidence for the synthesis of amino substituted distyrylbenzene and of nitro/alkoxy substituted poly(p-phenylene vinylene) was obtained. Characterization of the products was performed by 1H-NMR. Preliminary results of the synthesis of a novel amino-substituted distyrylbenzene (DSB) are presented. The luminescence of the new DSB was …

Apan Production Through Photooxidation Of Isoprene In The Presence Of NoX, Timothy Glidewell

Masters Theses

Peroxyacyl nitrates (PANs, RC(O)OONO₂) are of great importance in atmospheric chemistry. They act as transporters of reactive nitrogen, and radical delivery agents. There are no known natural emission sources of PANs; they are produced through reaction of volatile organic compounds (VOCs) and nitrogen oxides (NO_x) in the atmosphere.

VOCs can enter the atmosphere through biogenic and anthropogenic pathways. It has been estimated that isoprene makes up 70% of the biogenic VOCs (BVOCs) emitted annually. Isoprene has been shown to impact ozone levels in both rural and urban areas by sequestering and transporting NO_x in the form …

Metastable-State Nh Photoacids And Organic Photo Carbon Monoxide Releasing Materials, Aluthwatte Rallage Nawodi Madhusanka Abeyrathna

Theses and Dissertations

The recently discovered metastable-state photoacids (mPAHs) can produce a large proton concentration with high efficiency and good reversibility upon irradiation with visible light with moderate intensity. Therefore, mPAHs can be conveniently incorporated in to different systems to control various proton-transfer processes. Recently, several applications of mPAHs have been demonstrated. However, none of the previously reported mPAHs can function at a pH 7.4. Thus, biological applications of mPAHs are limited. In this work, mPAHs that can reversibly release a proton in PBS buffer (pH = 7.4) under visible light are designed and synthesized. NH-PAH-1 is the first of this type of …

Metastable-State Photoacids And The Related Photo-Responsive Polymers, Zhuozhi Wang

Theses and Dissertations

Metastable-state photoacid is a type of photo-sensitive compounds that can release large amount of protons reversibly upon visible-light irradiation. Since being developed by our group in 2011, metastable-state photoacid has been utilized to develop many applications that involve controlling proton transfer processes. Since proton transfer process is one of the most common processes in nature, metastable-state photoacid is a powerful tool to control various processes with light. A introduction of metastable state photoacid is described in Chapter 1. In Chapter 2, metastable-state photoacids with different substituents were designed to study the relationship between their structures and physicochemical properties. In Chapter …

5-Oxo-Ete Antagonists In Allergic Disease; Design And Synthesis Of Affinity Chromatography Ligand For 5-Hedh; And Synthesis Of Isoprostanes As An Index For The Diagnosis In Alzheimer’S Disease, Qiuji Ye

Theses and Dissertations

Arachidonic acid (AA, 4, Figure 1) is a 20:4 (ω-6) fatty acid with a 20-carbon chain and four cis-double bonds, and the esterified form of AA in phospholipids can be enzymatically liberated by phospholipases (PL) and subsequently metabolized into a variety of physiologically important mediators known as eicosanoids (Figure 2). One of the most important eicosanoids is 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE, 17). The 5-oxo-ETE (17) is the most known potent chemotactic factors for human eosinophils, and it can stimulate the late-phase asthma attacks.¹ To determine how the biosynthesis of 5-oxo-ETE is regulated, so as to determine its pathophysiological roles in the …