Organic Chemistry Commons^™

Indolizine Donor-Based Dyes For Applications In Fluorescence Biological Imaging, William Meador

Honors Theses

NIR emissive fluorophores are intensely researched due to their potential to replace modern imaging procedures. Many molecular strategies have been employed in the literature to optimize fluorophores for deeper NIR absorption and emission, biocompatibility, and higher fluorescence quantum yields. Amongst the fluorophores studied to date, proaromatic indolizine donors are attractive alternatives to traditional alkyl amine and indoline based donors due to their 1) lower energy absorption and emission facilitated by proaromaticity, 2) large Stokes shifts due to increased dihedral angles about the π-system, 3) ease of functionalization and capacity for bioconjugation at the phenyl ring, and 4) potential for further …

Review Of Chemoselective Reagent Based-Breath Analysis Techniques, Madeline F. Mccloud

Grawemeyer Colloquium Papers

Volatile organic compounds (VOCs) pose a threat due to the negative effects of many compounds on human health. VOCs of interest are specific carbonyl compounds produced exogenously and endogenously, resultant of industrial pollution and diseases such as cancer. High concentrations of these carbonyl compounds are found in exhaled breath are linked to cancer, therefore non-invasive breath tests would prove beneficial for cancer diagnosis. Usage of chemoselective cationic reagents allows for efficient testing of these concentrations. The development of these breath tests is detailed in the report.

Methylation Of The D2 Dopamine Receptor Affects Binding With The Human Regulatory Proteins Par-4 And Calmodulin, Alexander Bowitch, Ansuman Sahoo, Andrea M. Clark, Christiana Ntangka, Krishna K. Raut, Paul Gollnick, Michael C. Yu, Steven M. Pascal, Sarah E. Walker, Denise M. Ferkey

Chemistry & Biochemistry Faculty Publications

No abstract provided.

Mechanism Of Action Of Dihydropteridine Reductase, Gabriela Arias De La Rosa

Dissertations, Theses, and Capstone Projects

Human dihydropteridine reductase is an enzyme that transfers a hydride from NADH to reduce quinonoid 7,8-dihydropterin (qBH₂) to 5,6,7,8-tetrahydropterin (BH₄), which is a cofactor important in the production of neurotransmitters.DHPR deficiency causes a drastic form of the neurological genetic disease phenylketonuria (PKU) that does not benefit from a phenylalanine-free diet.From site-directed mutagenesis studies, mostly on Rat DHPR, we know that certain residues are important for cofactor binding, substrate binding, and hydride transfer; however, there are still some questions about how DHPR works, particularly, because there is not a crystal structure of the tertiary complex: What is …

Interactions Of Organic Fluorophores With Plasmonic Surface Lattice Resonances, Robert J. Collison

Dissertations, Theses, and Capstone Projects

It is common knowledge that metals, alloys and pure elements alike, are lustrous and reflective, the more so when a metal surface is flat, polished, and free from oxidation and surface fouling. However, some metals reflect visible light, in the 380 nm to 740 nm range of wavelengths, much more strongly than others. In particular, some metals reflect wavelengths in certain portions of the ultraviolet (UV), visible, and near-infrared (NIR) regime, let us say 200 nm to 2000 nm, while absorbing light strongly in other segments of this range. There are several factors that account for this difference between various …

Using The Marcus Inverted Region And Artificial Cofactors To Create A Charge Separated State In De Novo Designed Proteins, Eskil Me Andersen

Dissertations, Theses, and Capstone Projects

To create an efficient de novo photosynthetic protein it is important to create long lived charge separated states. Achieving stable charge separation leads to an increase in the efficiency of the photosynthetic reaction which in turn leads to higher yields of end products, such as biofuels, electrical charge, or synthetic chemicals. In an attempt to create charge separated states in de novo proteins we hypothesized that we could engineer the free energy gaps in the proteins from excited primary donor (PD) to acceptor (A), and A back to ground state PD such that the forward electron transfer (ET) would be …

Design And Synthesis Of Non-Xanthone Structural Analogs Of Α-Mangostin, Maryam Foroozmehr

Theses and Dissertations

α-Mangostin belongs to a class of polyphenolic compounds called xanthones. The potential pharmacological effects such as anti-bacterial and anti-cancer effects of α-mangostin have made it an important natural product for medicinal chemistry evaluation. During this thesis research, we have designed and synthesized a series of non-xanthone analogs of α-mangostin for medicinal chemistry evaluation. A commercially available starting material, methyl-4-methoxysalicylate was used to synthesize these non-xanthone analogs. The analogs were designed as more flexible derivatives compared to the tricyclic motif within α-mangostin yet retain the hydroxybenzoate scaffold. Through a one-pot chemical synthesis, with relatively high yield (70%), we prepared eight different …

Photoassisted Synthesis Of Complex Polyheterocycles Via Rational Design Of Tailored Photoprecursors, Tina Alanna Holt

Electronic Theses and Dissertations

Natural products remain the most common source for drug leads, although diversity-oriented synthesis of unnatural complex molecules is gaining momentum. Our lab has been developing experimentally simple and straightforward approaches to complex molecular architectures via photochemical reactions involving a minimal number of experimental steps. In order to achieve this, photoprecursors were assembled via high yielding reactions. Next, we deployed photoinduced cycloadditions to create complex 3-dimentional structures. Lastly, with this obtained primary photoproduct, post-photochemical transformations were used to further grow its scaffold complexity.

One method to increase scaffold complexity is the [4+2] intramolecular cycloadditions of azaxylylenes, which are developed through standard …

Synthesis Of Cysteine-Tyrosine Crosslink, Samuel Braak, Michael Rettstatt, David Benson

Summer Research

Some posttranslationally-modified protein tyrosines, such as the crosslink between cysteine and tyrosine (Cys-Tyr) provide sites for reversible oxidation These crosslinks are formed by an adjacent, redox active metal center when reacted with O2 . While galactose oxidation was among the first documented cys-ty crosslinks, cross linked tyrosine PTM’s have three major functions.

The Photophysical Properties Of Grevillone (6- Hydroxycoumarin) And Methylgrevillone (6-Hydroxy-4- Methyl-Coumarin), Leah H. Knoor, Hyemin Seo, Liam Hoogewerf, George Du Laney, Isaac Jonker, Mark Muyskens

Summer Research

Grevillone (L) and methylgrevillone (R) are two of many natural compounds called coumarins. Coumarins are useful as antioxidants, antivirals, and more.

Synthesis Of A Series Of Ag(I)-Nhc Complexes For Future Antibacterial Studies, Alyssa Malto

Honors Program Theses

For thousands of years, silver (Ag) has been widely used for medicinal purposes due to its broad-spectrum antimicrobial properties. While medicinal silver usage declined with the advent of antibiotics, there has been a renewed interest in therapeutic silver coordination compounds to combat the spread of antibiotic resistance. N-heterocyclic carbenes (NHCs) are promising ligands for silver metallodrugs due to their wide structural variety that allows for tunability of the complex’s overall steric and electronic properties and previously established bioactivity against various pathogens and cancer cell lines. There is potential for efficacy against biofilms, a type of microbial growth pattern that is …

Convergent Synthesis Of Anaephene B, Megan Johnson

Honors Program Theses

Many organisms are capable of producing organic compounds as secondary metabolites; these natural products can be quite pharmaceutically and medicinally relevant.1 Typically, the more unique an organism, the more unique its secondary metabolites. Cyanobacteria, an abundant microalgal organism, is capable of producing a myriad of novel natural products.2 The unique photosynthetic and autotrophic properties of cyanobacteria allow for the production of many secondary metabolites, including lipopeptides, amino acids, fatty acids, macrolides, amides, and others.2,3 Staphylococcus aureus is one the most common bacterial infections in the world.4 S. aureus produces a number of metabolites that inhibit host immune responses.4 As a …

Mitochondrial Energetics With Transmembrane Electrostatically Localized Protons: Do We Have A Thermotrophic Feature?, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

Transmembrane electrostatically localized protons (TELP) theory has been recently recognized as an important addition over the classic Mitchell’s chemiosmosis; thus, the proton motive force (pmf) is largely contributed from TELP near the membrane. As an extension to this theory, a novel phenomenon of mitochondrial thermotrophic function is now characterized by biophysical analyses of pmf in relation to the TELP concentrations at the liquid-membrane interface. This leads to the conclusion that the oxidative phosphorylation also utilizes environmental heat energy associated with the thermal kinetic energy (k_BT) of TELP in mitochondria. The local pmf is now calculated to be in …

Discharge Mode Transition In He/Ar Atmospheric Pressure Plasma Jet And Its Inactivation Effect Against Tumor Cells In Vitro, Bolun Pang, Zhijie Liu, Sitao Wang, Yuting Gao, Huaiyan Zhang, Feng Zhang, Xiamin Tantai, Dehui Xu, Dingxin Liu, Michael G. Kong

Bioelectrics Publications

Discharge characteristic comparisons between He and Ar plasma jets have been extensively reported, but is rarely reported for the comprehensive study of discharge mode transition from He jet to Ar jet, especially its induced liquid chemistry and biological effect. In this paper, we investigate the plasma jet mode transformation by varying the Ar contents in the He/Ar mixing working gas, particularly focusing on the effect of liquid chemistry of plasma activated water (PAW) and the corresponding inactivation effect against tumor cells in vitro. The mode transition process from He jet to Ar jet is characterized by the discharge images, …

Energy Renewal: Isothermal Utilization Of Environmental Heat Energy With Asymmetric Structures, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

Through the research presented herein, it is quite clear that there are two thermodynamically distinct types (A and B) of energetic processes naturally occurring on Earth. Type A, such as glycolysis and the tricarboxylic acid cycle, apparently follows the second law well; Type B, as exemplified by the thermotrophic function with transmembrane electrostatically localized protons presented here, does not necessarily have to be constrained by the second law, owing to its special asymmetric function. This study now, for the first time, numerically shows that transmembrane electrostatic proton localization (Type-B process) represents a negative entropy event with a local protonic entropy …

Synthesis Of Carbohydrate Based Macrolactones And Their Applications As Receptors For Ion Recognition And Catalysis, Surya B. Adhikari, Anji Chen, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Glycomacrolactones exhibit many interesting biological properties, and they are also important in molecular recognitions and for supramolecular chemistry. Therefore, it is important to be able to access glycomacrocycles with different sizes and functionality. A new series of carbohydrate-based macrocycles containing triazole and lactone moieties have been designed and synthesized. The synthesis features an intramolecular nucleophilic substitution reaction for the macrocyclization step. In this article, the effect of some common sulfonate leaving groups is evaluated for macrolactonization. Using tosylate gave good selectivity for monolactonization products with good yields. Fourteen different macrocycles have been synthesized and characterized, of which eleven macrocycles are …

A Novel Palladium Bodipy Photocatalyst For Sonogashira Carbon-Carbon Cross-Coupling, Prahadeesh Nagaretnam

Masters Theses

No abstract provided.

Methodology For C-Glycosylation And Synthesis Of Probes For The Detection Of Cysteine Containing Proteins, Elizabeth Ward

Undergraduate Honors Theses

Throughout my research I have been able to expand my knowledge and gain experience in organic chemistry by working on projects related to biochemistry and hydrocarbons. The projects I have worked on were:

• Project 1: C-glycosylation through photo irradiation with reductive halide atom transfer
• Project 2: Synthesis of rhodamine and biotin probes for the detection of cysteine containing proteins
• Project 3: Literature review on: Fluorescent probes for cysteine containing proteins

Labilization And Diversification Of Pyrogenic Dissolved Organic Matter By Microbes, Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

With the increased occurrence of forest fires around the world, interest in the chemistry of pyrogenic organic matter (pyOM) and its fate in the environment has increased. Upon leaching from soils by rain events, significant amounts of dissolved pyOM (pyDOM) enter the aquatic environment and interact with microbial communities that are essential for cycling organic matter within the different biogeochemical cycles. To evaluate the bio-reactivity of pyDOM, aqueous extracts of laboratory-produced chars were incubated with soil microbes and the molecular changes to the composition of pyDOM were probed using ultrahigh resolution mass spectrometry (Fourier transform – ion cyclotron resonance – …

Structual Analysis Of The Cl-Par-4 Tumor Suppressor As A Function Of Ionic Environment, Krishna K. Raut, Komala Ponniah, Steven M. Pascal

Chemistry & Biochemistry Faculty Publications

Prostate apoptosis response-4 (Par-4) is a proapoptotic tumor suppressor protein that has been linked to a large number of cancers. This 38 kilodalton (kDa) protein has been shown to be predominantly intrinsically disordered in vitro. In vivo, Par-4 is cleaved by caspase-3 at Asp-131 to generate the 25 kDa functionally active cleaved Par-4 protein (cl-Par-4) that inhibits NF-κB-mediated cell survival pathways and causes selective apoptosis in tumor cells. Here, we have employed circular dichroism (CD) spectroscopy and dynamic light scattering (DLS) to assess the effects of various monovalent and divalent salts upon the conformation of cl-Par-4 in vitro. We have …