Organic Chemistry Commons^™

Pyrocumulonimbus Stratospheric Plume Injections Measured By The Ace‐Fts, C.D. Boone, Peter F. Bernath, M. D. Fromm

Chemistry & Biochemistry Faculty Publications

The Atmospheric Chemistry Experiment (ACE) is a satellite‐based mission that probes Earth's atmosphere via solar occultation. The primary instrument on board is a high‐resolution infrared Fourier transform spectrometer (Atmospheric Chemistry Experiment Fourier Transform Spectrometer, ACE‐FTS), providing altitude‐resolved volume mixing ratio measurements for numerous atmospheric constituents, including many biomass burning products. The ACE mission has observed the aftermath of three major pyrocumulonimbus events, in which extreme heat from intense fires created a pathway for directly injecting into the stratosphere plumes of gaseous and aerosol pollutants. These three events were associated with severe Australian bushfires from 2009 and 2019/2020, along with intense …

Molecular Nature Of Marine Particulate Organic Iron-Carrying Moieties Revealed By Electrospray Ionization Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (Esi-Fticrms), Chen Xu, Peng Lin, Luni Sun, Hongmei Chen, Wei Xing, Manoj Kamalanathan, Patrick G. Hatcher, Maureen H. Conte, Antonietta Quigg, Peter H. Santschi

Chemistry & Biochemistry Faculty Publications

Marine sinking particulate organic matter (POM), acting as a link between surface primary production and burial of organic matter in marine sediments, undergoes a variety of physical and biochemical alterations on its way to the deep ocean, resulting in an increase in its un-characterizable proportion with diagenesis. Further, the binding ligands in POM for iron, an essential nutrient to marine life and tightly coupled with organic matter, has rarely been studied. In the current study, we employed an approach combining sequential extraction with ultrahigh resolution mass spectrometry (ESI-FTICRMS), in order to explore and unravel the chemical characteristics of organic matter …

Influences Of Hillslope Biogeochemistry On Anaerobic Soil Organic Matter Decomposition In A Tundra Watershed, Michael Philben, Neslihan Taş, Hongmei Chen, Stan D. Wullschleger, Alexander Kholodov, David E. Graham, Baohua Gu

Chemistry & Biochemistry Faculty Publications

We investigated rates and controls on greenhouse gas (CO₂ and CH₄) production in two contrasting water‐saturated tundra soils within a permafrost‐affected watershed near Nome, Alaska, United States. Three years of field sample analysis have shown that soil from a fen‐like area in the toeslope of the watershed had higher pH and higher porewater ion concentrations than soil collected from a bog‐like peat plateau at the top of the hillslope. The influence of these contrasting geochemical and topographic environments on CO₂ and CH₄ production was tested in soil microcosms by incubating both the organic‐ and mineral‐layer …

Thyroxine Binding To Type Iii Iodothyronine Deiodinase, Craig A. Bayse, Eric S. Marsan, Jenna R. Garcia, Alexis T. Tran-Thompson

Chemistry & Biochemistry Faculty Publications

Iodothyronine deiodinases (Dios) are important selenoproteins that control the concentration of the active thyroid hormone (TH) triiodothyronine through regioselective deiodination. The X-ray structure of a truncated monomer of Type III Dio (Dio3), which deiodinates TH inner rings through a selenocysteine (Sec) residue, revealed a thioredoxin-fold catalytic domain supplemented with an unstructured Ω-loop. Loop dynamics are driven by interactions of the conserved Trp207 with solvent in multi-microsecond molecular dynamics simulations of the Dio3 thioredoxin(Trx)-fold domain. Hydrogen bonding interactions of Glu200 with residues conserved across the Dio family anchor the loop's N-terminus to the active site Ser-Cys-Thr-Sec sequence. A key long-lived loop …

Oxidation Of Aldehydes To Nitriles With An Oxoammonium Salt: Preparation Of Piperonylonitrile, Nathaniel D. Kaetzel, Kyle M. Lambert, Christopher B. Kelly

Chemistry & Biochemistry Faculty Publications

No abstract provided.

Synthesis, Characterization, And Biological Activity Of Imidazolium Salts, David Weader

Williams Honors College, Honors Research Projects

Nonmuscle invasive bladder cancer (NMIBC) inflicts thousands of Americans annually, and is typically treated with the immunotherapy BCG. However, due to a BCG shortage, there is a new need for novel treatments of NMIBC. Addressing this issue, several imidazolium salt derivatives were synthesized and characterized with the intent of treatment within the bladder. These imidazolium salts were tested against different human bladder cancer cell lines in vitro to determine their reactivity and cytotoxicity. Among these results are GI50 concentrations for each drug, which is the concentration of drug needed to see growth inhibition in 50% of treated cells. Previous published …

Improving The Value Of The Coconut With Biotechnology, Fabian M. Dayrit, Quang Nguyen

Chemistry Faculty Publications

The fruit of the coconut tree is perhaps the most useful plant resource in the tropics. All parts of the coconut fruit have traditional uses that have been developed commercially in recent times (Foale 2003, Dayrit and Dayrit 2013). Due to its widespread household use, trade and industry statistics on coconut products reflect only part of the actual importance of the coconut. Today, coconut-based products have gone beyond the tropics and are consumed in many temperate countries and global regions such as Australia, China, Europe, North America, and the Middle East (Costello 2018). Coconut milk is the basic ingredient of …

Feasibility Of Cyclodextrin-Potassium Ion Assemblies Synthesis And Its Application In Loading Bio-Active Molecules, Yomkippur Perez, Gilbert U. Yu

Chemistry Faculty Publications

In the study, colorless cubic crystals of “green” cyclodextrin (CD)-based assemblies were synthesized and their potential to load bio-active molecules such as drugs and, separately, enzymes were investigated. Busulfan (Bu), an anti-cancer drug widely used to treat chronic myelogenous leukemia (CML), was used as a test drug while trypsin and lipase were used as model enzymes. These porous CD-K+ ion assemblies were prepared by dissolving alkali metal salts and γ-CD in water followed by vapor diffusion in varying solvents for several days. Crystals were activated via dichloromethane dispersion and in vacuo drying. Slow vapor diffusion with ethanol was found to …

Selective Synthesis Of Trans-Fused Lactam-Lactones By Vicinal Difunctionalization Of Readily Affordable Allylic Lactams, Morgan J. Rodriguez

All Master's Theses

With intrinsic versatility and an overwhelming presence in natural products, nitrogen- and oxygen-containing heterocycles boast a plethora of medicinal properties. Specifically, lactams and lactones are the respective luminaries of the antibiotic and flavor worlds. However, the synthesis of fused lactams-lactones, especially those bearing trans-fusion, is challenging from the standpoints of chemoselectivity, stereoselectivity, and regioselectivity. In this thesis, the highly-selective, cost-effective, and high-yielding conversion of readily affordable allylic lactams into trans-fused lactam-lactones by intramolecular vicinal difunctionalization is explored. The approach is highly divergent and requires only two steps, which bodes well for the construction of medicinally pertinent fragments. It …

Silver-Mediated Decarboxylation Reactions: Expanding Reaction Scope Through Kinetic Analysis, Robert Anthony Crovak

Graduate Theses, Dissertations, and Problem Reports (ETD)

Transition metal-catalyzed decarboxylative coupling reactions have received considerable attention in recent years as a method to obtain biaryl compounds. However, the oxidative version of this reaction class is still in its infancy, limited to specific substitution patterns on the benzoic acids – ortho-substitution - used in these transformations. This thesis describes our attempts to understand the key decarboxylation step of this important class of reactions. The first chapter of this thesis discusses an introduction into cross-coupling reactions, decarboxylative cross-coupling reactions, and outlines relevant physical organic parameters. The following chapter details the synthesis of a series of (1,10-phenanthroline)silver(benzoate) complexes. This chapter …

Development Of New Synthetic Methods For Carbon Nanohoops, Merfat Aljhdli

Graduate Theses, Dissertations, and Problem Reports (ETD)

Carbon nanotubes have received much attention from the material chemists after the synthesis and structure analysis by Iijima in 1991. It was envisioned that cycloparaphenylenes (CPPs), which comprise a sequence of benzene units connected at para position to make a cyclic ring structure, are possible templates for growing carbon nanotubes of a single chirality and single diameter for nanotechnology application. Recently, chemists turned their attention to synthesizing aromatic carbon nanobelts proposed as a general term for carbon molecules composed of fused benzene rings in cylindrical structure shape. Cyclophenacenes (CPAs) as carbon nanobelts are expected to be more suitable candidates for …

Synthesis Of Bio-Based Polymer Products, Joshua Sukie

Williams Honors College, Honors Research Projects

The project covers the synthesis of two bio-based polymers. One aspect of the research investigates the synthesis of materials for use in vegetable oil-based UV-curable coating, and the subsequent polymerization of the materials into a coating film. The second aspect of the research follows the synthesis of a functionalized cellulose material for use as a reinforcer in a vegetable oil-based composite. Both products are subsequently analyzed by various methods.

Filtration Apparatus Design For Oil-Water Separation Using Membranes And Sponges, Alec Jerger

Williams Honors College, Honors Research Projects

It can be difficult to separate water and oil emulsions through traditional filtration. Therefore, investigations of filtering using thermo-responsive (TR) polymers, in this case poly(vinyl methyl ether) (PVME), was conducted. It’s hypothesized that below its lower critical solution temperature (LCST), PVME has an affinity for water while oil substances do not. Above the LCST the opposite will be true. To verify this hypothesis, iterations of filtration designs were created to provide optimum control over the parameters to measure flow. The final optimized experimental apparatus was a Chromaflex glass column which was air tight and controlled all parameters besides fluid flow. …

Metabolomic Study Of The Lew.1wr1 Rat: Serum Artificial Mixture Validation, Jennifer S. Nix

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

No abstract provided.

Synthesis And The Genetic Encoding Of Novel Lysine Post-Translational Modifications, Sahan A. Galbada Liyanage

Theses and Dissertations

Post-translational modifications (PTMs) play a significant role in regulating cell signaling and regulating the inner cellular environment. The study of PTMs and their primary biological functions is critical for the development of new medicines targeting the pathways and biomolecules responsible for the PTMs.

Previous studies revealed the direct coupling of the β -hydroxybutyryl lysine (K_BHB) modification with the gene expression. K_BHB in histone proteins links metabolism to epigenetics and gene expression and enables to study in-depth, how cell metabolism controls the gene expression and vice versa. Similar novel histone modification, K_Lac, attracts a special interest …

Towards A Greener Route To Blockbuster Statin Drugs: Harnessing The Power Of Biocatalysis And Integrating Cross-Coupling Catalysis In The Synthesis Of Rosuvastatin, Chanaka M. Amarasekarage

Theses and Dissertations

As global and political awareness about green and sustainable practices sharpens in the face of dramatic climate change and environmentally detrimental practices, one attractive approach is to harness the catalytic potential of enzymes. Thus influenced, our efforts focused on the development of an innovative chemoenzymatic route to widely prescribed Blockbuster statin drugs, specifically rosuvastatin. In this work, we engineered novel deoxyribose phosphate aldolase (DERA) variants via rationally designed site-directed mutagenesis to accept non-natural, less polar substrate, acrolein, along with acetaldehyde. Several of new mutants displayed elevated tolerance towards aldehydes and showed effective incorporation of acrolein into the unprecedented enzymatically-derived chiral …

Sugar-Derived Oleogels In Cosmetics And Food Applications: A Case Study Of Trehalose- And Mannitol-Based Gelators, Polina Tsupko

Dissertations and Theses

Gels represent an indispensable part of our everyday lives with direct applications in food, medicine, cosmetics and other industries. Amphiphilic molecules have been shown to act as low molecular weight gelators (LMWGs) and are becoming the main focus of several research groups. Their ability to self-assemble into various morphologies from micelles to bilayer sheets, and remain stable due to noncovalent forces responsible for the formation of the 3D network—Self-Assembled Fibrillar Network (SAFiNs)—is in the core of their ability to produce molecular gels. Those amphiphilic molecules capable of adsorbing at the interface and behaving as surface active agents are known as …

Reductions By Cobalt-Catalyzed Production Of Hydrogen Gas From Nabh4 In A Two-Chamber System, Joshua K. Mitchell

Dissertations and Theses

The work outlined in this thesis describes a bench-scale methodology involving a two-chamber system for conducting catalytic hydrogenation reactions by obtaining hydrogen (H₂) gas from stable sodium borohydride (NaBH₄). Whereas NaBH₄ is widely used for a variety of reductions and is known to produce H₂ gas in protic media, to our knowledge, there has been scant use of NaBH₄ in catalytic hydrogenation chemistry where it has been used as a source of H₂ gas. In this work, addition of a catalytic amount of CoCl₂•6H₂O as an aqueous solution …

Redox-Active Porous Organic Materials For Electrochemical Energy Storage Applications, K. Shamara Weeraratne

Theses and Dissertations

As the demand for renewable energy technologies grows, so does the need for cheaper, more efficient rechargeable batteries to store the energy. While lithium-ion battery (LIBs) technology is well established, it suffers from limited lithium supplies. Furthermore, the highly toxic transition metals used in the electrodes places a huge burden on the environment. Therefore, replacing lithium with more economical sodium metal in rechargeable batteries (i.e. sodium-ion batteries, SIBs) has garnered considerable attention. Despite the fact that sodium and lithium share similar electrochemical properties, which may cause the transition from lithium to sodium easier, the larger ionic radius of Na^{+ …}

Design, Synthesis, And Characterization Of Chemical Tools To Study Peroxisomal Import, Jhalak N. Timilsena

Masters Theses

Peroxisomes are dynamic and interconnected single lipid membrane bound organelles found in the eukaryotic cells which are involved in various biochemical processes including the b-oxidation of very long chain and branched chain fatty acids, metabolism of reactive oxygen and nitrogen species, and reduction of hydrogen peroxide among others. These organelles are known to host numerous proteins and enzymes depending on the cellular environment. All of the proteins needed in the peroxisomes are encoded in the nucleus and synthesized in the cytosol which are then transported to the peroxisomes with the help of a sophisticated protein-transport machinery. Pex5 is one of …