Chemistry Commons^™

From Rags To Riches, From Waste To Valuables: Towards A Sustainable Fuel Additive, Jonathan Kilroy

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Detecting Haloacetic Acids Using Chromatography, Nathan Perinovic

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

The Stress Granule Transcriptome Reveals Principles Of Mrna Accumulation In Stress Granules, Sarah F. Mitchell

Chemistry and Biochemistry Faculty Works

Stress granules are mRNA-protein assemblies formed from nontranslating mRNAs. Stress granules are important in the stress response and may contribute to some degenerative diseases. Here, we describe the stress granule transcriptome of yeast and mammalian cells through RNA-sequencing (RNA-seq) analysis of purified stress granule cores and single-molecule fluorescence in situ hybridization (smFISH) validation. While essentially every mRNA, and some noncoding RNAs (ncRNAs), can be targeted to stress granules, the targeting efficiency varies from <1% to >95%. mRNA accumulation in stress granules correlates with longer coding and UTR regions and poor translatability. Quantifying the RNA-seq analysis by smFISH reveals that only 10% of …

Metabolomic Profiling Of Chiari Malformation Type I: Comparison Of Bioinformatic Programs For Untargeted Analysis, Hunter W. Korsmo

Williams Honors College, Honors Research Projects

Chiari Malformation Type I is a neurodegenerative trait that can result from disease or from acquiring. Metabolomic analysis was done on normal pressure hydrocephalous and Chiari CSF samples using LC-MS and multiple bioinformatic programs. After analysis from multiple programs, we were able to analyze the stringency in statistical algorithms done by each program and determined qualities that are shared between programs that offer multiple details. We identified dysregulation in glucuronated metabolites in CSF of Chiari versus NPH. Using LC-MS, we established the experimental MS/MS of glucuronic acid in attempt to identify similarities in mass-to-charge features primarily identified. We could not …

An Analysis Of The Acid Profile Of Coffee Brews: Caffeine And Chlorogenic Acid Concentrations In Different Forms Of Coffee Brew, Jeffory Taylor Wallace

Honors Theses

In this project, different coffee brews were analyzed in order to determine the effects the brewing method had on the final product, particularly the acid profile of the final product. Our hypothesis is that the use of a cold brewing method will produce different amounts of caffeine and chlorogenic acids in the final brewed product compared to traditional hot brewing methods. There are many brewing methods available. For the purposes of this research, three were chosen and one was created. The three chosen methods were: a traditional drip brew, a cold brew, and a Pezzetti espresso brew. The final method …

Raman Spectroscopic Studies Of Novel Gold-Containing Nanomaterials, Lemuel Shui-Lun Tsang

Honors Theses

The thiolate-protected gold nanocluster (AuNP) Au38(SCH2CH2Ph)24 was studied using Raman spectroscopy with particular attention to the vibrational modes of the gold-sulfur interface. Such studies of AuNPs are non-trivial, as these materials are weak scatterers that burn and fluoresce readily. Previous works have successfully studied this class of materials using a rolling circle filter to subtract fluorescence backgrounds, but we set out to develop a method which would suppress fluorescence using more fundamental means. For Au38(SCH2CH2Ph)24, it was found that data acquisition was most effective using lower-energy excitation wavelengths, which could be predicted based on the UV-Vis absorption spectrum of the …

Introducing Global Peat-Specific Temperature And Ph Calibrations Based On Brgdgt Bacterial Lipids, B.D.A. Naafs, G. N. Imglis, Y. Zheng, M. J. Amesbury, H. Biester, R. Bindler, J. Blewett, M. A. Burrows, D. Del Castillo Torres, F. M. Chambers, P. G. Hatcher

Chemistry & Biochemistry Faculty Publications

Glycerol dialkyl glycerol tetraethers (GDGTs) are membrane-spanning lipids from Bacteria and Archaea that are ubiquitous in a range of natural archives and especially abundant in peat. Previous work demonstrated that the distribution of bacterial branched GDGTs (brGDGTs) in mineral soils is correlated to environmental factors such as mean annual air temperature (MAAT) and soil pH. However, the influence of these parameters on brGDGT distributions in peat is largely unknown. Here we investigate the distribution of brGDGTs in 470 samples from 96 peatlands around the world with a broad mean annual air temperature (−8 to 27 °C) and pH (3–8) range …

The Synthesis Of 3,5-Difluorobenzophenone Derivatives And Their Corresponding Peek Copolymers, Rachael Stuck

Browse all Theses and Dissertations

Poly(aryl ether ketone)s (PAEK) are high performance thermoplastics, which are chemically robust, semi-crystalline, and stable at high temperatures. Of the family of PAEKs, poly(ether ether ketone) (PEEK) is a well-known semi-crystalline thermoplastic widely used for electronics, energy, industrial, and medical applications due to its resistance to solvents, radiation, heat, and other environmental factors. The traditional PEEK is prepared from 4,4’-difluorobenzophenone (2) and disodium hydroquinone. However, a challenge is processability, since due to its highly crystalline nature, PEEK possesses very limited solubility. An approach to solve these issues is to pre-functionalize PEEK polymers synthesized by nucleophilic aromatic substitution from 3,5-difluorobenzophenone (1) …

Toward The Synthesis Of Functionalized Poly (Ether Ether Ketone): Monitoring The Meta-Fluorine Displacement In 3,5,4’-Trifluorobenzophenone, Giovanni Covarrubias

Browse all Theses and Dissertations

The synthesis of functionalized, linear poly (ether ether ketone), tailored to be semi-crystalline and soluble in a variety of organic-solvents was explored. Nucleophilic aromatic substitution was a chemical reaction method used to condense 3,5,4’-trifluorobenzophenone (TFK) with four different phenols at its para-positioned carbon-fluorine site: 4-methoxyphenol, 3-aminophenol, 4-bromophenol, and m-cresol. Further poly-condensation of functionalized TFK occurred at the meta-positioned carbon-fluorine sites with 4,4’-Bis[4-hydroxyphenoxy] benzophenone (Big A2) and 4,4’-difluorobenzophenone at molar equivalents of 1 to 0.5, respectively. The reaction afforded products that became insoluble in solvents needed for nuclear magnetic resonance spectroscopic (e.g. DMSO-d6) analysis. The lack of desirable compounds compelled the …

Synthesis Of Alkyl Substituted Phenylated Poly(Ether Ether Ketone Ketone)S, Matthew Cerone

Browse all Theses and Dissertations

A phenylated bis(fluorobenzoyl) monomer, 5-hexyl-2,3-diphenyl-1,4-bis(fluorobenzoyl)benzene, was synthesized via a four-step process. The first three compounds synthesized were diethyl 5-hexyl-2,3-diphenyl-1,4-benzenedicarboxylate, 5-hexyl-1,4-bis(hydroxymethyl)-2,3-diphenylbenzene and 5-hexyl-2,3-diphenyl-1,4-benzenedicarboxaldehyde. The final step involved the reaction of the Grignard formed from p-bromofluorobenzene with the dialdehyde to yield a diol intermediate which was oxidized to the bis(fluorobenzoyl) monomer by use of a Jones oxidation. The monomer was polymerized by nucleophilic aromatic substitution (NAS) with bisphenol-A, resorcinol, and hydroquinone in N-methyl-pyrrolidone (NMP) to yield novel, phenylated PEEKKs. The number-average molecular weights (Mn) for the polymers were found to be 35,700 g/mol, 34,800 g/mol and 28,000 g/mol, respectively and the weight-average …

Investigating Potential Pollutant Sources Causing Lack Of Biodiversity In Lytle Creek And Indian Run, Amira Moayad Alsenbel

Browse all Theses and Dissertations

Limited macroinvertebrate biodiversity in Lytle Creek that runs through downtown Wilmington, Ohio has been documented over decades with the lowest in Lytle Creek at Sugar Grove Cemetery. Lytle Creek, a tributary of the Little Miami River, is a conduit for storm water and wastewater from an airport, downtown storm water with input from local businesses, and a wastewater treatment plant. This study was conducted to see if heavy metal pollution in the sediment, water quality, and Escherichia coli (E. coli) could be contributing factors in reduced macroinvertebrate populations. Eight sites were chosen for sediment sampling to measure trace metals. Mercury …

Antimicrobial Activity Of Fractionated Borohydride-Capped And Electrochemical Colloidal Silver, Marjorie M. Markopoulos

Browse all Theses and Dissertations

Silver nanoparticles (AgNPs) and ionic silver (Ag+) are known to be broad-spectrum antimicrobial agents. Recent studies show these agents may be an alternative to the most widely used drinking water disinfectant, chlorine. Chlorine is a toxic industrial chemical with a lethal concentration of 430 ppm after 30 minutes. Additionally, chlorine can react with naturally occurring materials to produce a number of disinfection byproducts such as chloroform and trihalomethanes. Some of these byproducts pose cancer risks in addition to other negative impacts to human health. These would be eliminated with the use of Ag+ or AgNPs. The main goal of this …

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 …

Criegee Intermediate-Hydrogen Sulfide Chemistry At The Air/Water Interface, Manoj Kumar, Jie Zhong, Joseph S. Francisco, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We carry out Born–Oppenheimer molecular dynamic simulations to show that the reaction between the smallest Criegee intermediate, CH₂OO, and hydrogen sulfide (H₂S) at the air/water interface can be observed within few picoseconds. The reaction follows both concerted and stepwise mechanisms with former being the dominant reaction pathway. The concerted reaction proceeds with or without the involvement of one or two nearby water molecules. An important implication of the simulation results is that the Criegee-H₂S reaction can provide a novel non-photochemical pathway for the formation of a C–S linkage in clouds and could be a …

Metabolic Investigations Of The Molecular Mechanisms Associated With Parkinson’S Disease, Robert Powers, Shulei Lei, Annadurai Anandhan, Darrell D. Marshall, Bradley Worley, Ronald Cerny, Eric D. Dodds, Yuting Huang, Mihalis I. Panayiotidis, Aglaia Pappa, Rodrigo Franco

Robert Powers Publications

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by fibrillar cytoplasmic aggregates of α-synuclein (i.e., Lewy bodies) and the associated loss of dopaminergic cells in the substantia nigra. Mutations in genes such as α -synuclein (SNCA) account for only 10% of PD occurrences. Exposure to environmental toxicants including pesticides and metals (e.g., paraquat (PQ) and manganese (Mn)) is also recognized as an important PD risk factor. Thus, aging, genetic alterations, and environmental factors all contribute to the etiology of PD. In fact, both genetic and environmental factors are thought to interact in the promotion of idiopathic PD, but the mechanisms …

Amino Acid Catabolism In Staphylococcus Aureus And The Function Of Carbon Catabolite Repression, Cortney R. Halsey, Shulei Lei, Jacqueline K. Wax, Mckenzie K. Lehman, Austin S. Nuxoll, Laurey Steinke, Marat Sadykov, Robert Powers, Paul D. Fey

Department of Chemistry: Faculty Publications

Staphylococcus aureus must rapidly adapt to a variety of carbon and nitrogen sources during invasion of a host. Within a staphylococcal abscess, preferred carbon sources such as glucose are limiting, suggesting that S. aureus survives through the catabolism of secondary carbon sources. S. aureus encodes pathways to catabolize multiple amino acids, including those that generate pyruvate, 2-oxoglutarate, and oxaloacetate. To assess amino acid catabolism, S. aureus JE2 and mutants were grown in complete defined medium containing 18 amino acids but lacking glucose (CDM). A mutation in the gudB gene, coding for glutamate dehydrogenase, which generates 2-oxoglutarate from glutamate, significantly reduced …

Laterally Extended Atomically Precise Graphene Nanoribbons With Improved Electrical Conductivity For Efficient Gas Sensing, Mohammad Mehdi Pour, Andrey Lashkov, Adrian Radocea, Ximeng Liu, Tao Sun, Alexey Lipatov, Rafal A. Korlacki, Mikhail Shekhirev, Narayana R. Aluru, Joseph W. Lyding, Victor Sysoev, Alexander Sinitskii

Department of Chemistry: Faculty Publications

Narrow atomically precise graphene nanoribbons hold great promise for electronic and optoelectronic applications, but the previously demonstrated nanoribbon-based devices typically suffer from low currents and mobilities. In this study, we explored the idea of lateral extension of graphene nanoribbons for improving their electrical conductivity. We started with a conventional chevron graphene nanoribbon, and designed its laterally extended variant. We synthesized these new graphene nanoribbons in solution and found that the lateral extension results in decrease of their electronic bandgap and improvement in the electrical conductivity of nanoribbon-based thin films. These films were employed in gas sensors and an electronic nose …

Nanomaterials As Stationary Phases And Supports In Liquid Chromatography: A Review, Sandya Beeram, Elliott Rodriguez, Suresh Doddavenkatanna, Zhao Li, Allegra Pekarek, Darin Peev, Kathryn Goerl, Gianfranco Trovato, Tino Hofmann, David S. Hage

Department of Chemistry: Faculty Publications

The development of various nanomaterials over the last few decades has led to many applications for these materials in liquid chromatography (LC). This review will look at the types of nanomaterials that have been incorporated into LC systems and the applications that have been explored for such systems. A number of carbon-based nanomaterials and inorganic nanomaterials have been considered for use in LC, ranging from carbon nanotubes, fullerenes and nanodiamonds to metal nanoparticles and nanostructures based on silica, alumina, zirconia and titanium dioxide. Many ways have been described for incorporating these nanomaterials into LC systems. These methods have included covalent …

A Surface-Stabilized Ozonide Triggers Bromide Oxidation At The Aqueous Solution-Vapour Interface, Luca Artiglia, Jacinta Edebeli, Fabrizio Orlando, Shuzhen Chen, Ming-Tao Lee, Pablo Corral Arroyo, Anina Gilgen, Thorsten Bartels-Rausch, Armin Kleibert, Mario Vazdar, Marcelo Andrea Carignano, Joseph S. Francisco, Paul B. Shepson, Ivan Gladich, Markus Ammann

Department of Chemistry: Faculty Publications

Oxidation of bromide in aqueous environments initiates the formation of molecular halogen compounds, which is important for the global tropospheric ozone budget. In the aqueous bulk, oxidation of bromide by ozone involves a [Br•OOO⁻] complex as intermediate. Here we report liquid jet X-ray photoelectron spectroscopy measurements that provide direct experimental evidence for the ozonide and establish its propensity for the solution-vapor interface. Theoretical calculations support these findings, showing that water stabilizes the ozonide and lowers the energy of the transition state at neutral pH. Kinetic experiments confirm the dominance of the heterogeneous oxidation route established by this precursor …

Cytotoxic Polyketides With An Oxygen-Bridged Cyclooctadiene Core Skeleton From The Mangrove Endophytic Fungus Phomosis Sp. A818, Wei Zhang, Baobing Zhao, Liangcheng Du, Yuemao Shen

Department of Chemistry: Faculty Publications

Plant endophytic microorganisms represent a largely untapped resource for new bioactive natural products. Eight polyketide natural products were isolated from a mangrove endophytic fungus Phomosis sp. A818. The structural elucidation of these compounds revealed that they share a distinct feature in their chemical structures, an oxygen-bridged cyclooctadiene core skeleton. The study on their structure–activity relationship showed that the α,β-unsaturated δ-lactone moiety, as exemplified in compounds 1 and 2, was critical to the cytotoxic activity of these compounds. In addition, compound 4 might be a potential agonist of AMPK (5'-adenosine monophosphate-activated protein kinase).

Chemoselective Alteration Of Fluorophore Scaffolds As A Strategy For The Development Of Ratiometric Chemodosimeters, Xinqi Zhou, Lauren Lesiak, Rui Lai, Jon R. Beck, Jia Zhao, Christian Elowsky, Hui Li, Cliff I. Stains

Department of Chemistry: Faculty Publications

Ratiometric sensors generally couple binding events or chemical reactions at a distal site to changes in the fluorescence of a core fluorophore scaffold. However, such approaches are often hindered by spectral overlap of the product and reactant species. We provide a strategy to design ratiometric sensors that display dramatic spectral shifts by leveraging the chemoselective reactivity of novel functional groups inserted within fluorophore scaffolds. As a proof-of-principle, fluorophores containing a borinate (RF₆₂₀) or silanediol (SiOH2R) functionality at the bridging position of the xanthene ring system are developed as endogenous H₂O₂ sensors. Both …

The Future Of Nmr-Based Metabolomics, John L. Markley, Rafael Bruschweiler, Arthur S. Edison, Hamid R. Eghbalnia, Robert Powers, Daniel Raftery, David S. Wishart

Department of Chemistry: Faculty Publications

The two leading analytical approaches to metabolomics are mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. Although currently overshadowed by MS in terms of numbers of compounds resolved, NMR spectroscopy offers advantages both on its own and coupled with MS. NMR data are highly reproducible and quantitative over a wide dynamic range and are unmatched for determining structures of unknowns. NMR is adept at tracing metabolic pathways and fluxes using isotope labels. Moreover, NMR is non-destructive and can be utilized in vivo. NMR results have a proven track record of translating in vitro findings to in vivo clinical …

Resolving The Cofactor-Binding Site In The Proline Biosynthetic Enzyme Human Pyrroline-5-Carboxylate Reductase 1, Emily M. Christensen, Sagar M. Patel, David A. Korasick, Ashley C. Campbell, Kurt L. Krause, Donald F. Becker, John J. Tanner

Department of Chemistry: Faculty Publications

Pyrroline-5-carboxylate reductase (PYCR) is the final enzyme in proline biosynthesis, catalyzing the NAD(P)H-dependent reduction of [?]1-pyrroline-5-carboxylate (P5C) to proline. Mutations in the PYCR1 gene alter mitochondrial function and cause the connective tissue disorder cutis laxa. Furthermore, PYCR1 is overexpressed in multiple cancers, and the PYCR1 knock-out suppresses tumorigenic growth, suggesting that PYCR1 is a potential cancer target. However, inhibitor development has been stymied by limited mechanistic details for the enzyme, particularly in light of a previous crystallographic study that placed the cofactor-binding site in the C-terminal domain rather than the anticipated Rossmann fold of the N-terminal domain. To fill this …

Indole-Induced Reversion Of Intrinsic Multiantibiotic Resistance In Lysobacter Enzymogenes, Yong Han, Yan Wang, Yameng Yu, Haotong Chen, Yuemao Shen, Liangcheng Du

Department of Chemistry: Faculty Publications

Lysobacter species are a group of environmental bacteria that are emerging as a new source of antibiotics. One characteristic of Lysobacter is intrinsic resistance to multiple antibiotics, which had not been studied. To understand the resistance mechanism, we tested the effect of blocking two-component regulatory systems (TCSs) on the antibiotic resistance of Lysobacter enzymogenes, a prolific producer of antibiotics. Upon treatment with LED209, an inhibitor of the widespread TCS QseC/QseB, L. enzymogenes produced a large amount of an unknown metabolite that was barely detectable in the untreated culture. Subsequent structural elucidation by nuclear magnetic resonance (NMR) unexpectedly revealed that …