Chemistry Commons^™

Theory Of Aqueous Solvation: Uninterrupted, Cyclic Hydrogen-Bonding Essential For Accurate Keto-Enol Energies And Grotthuss Tautomerism Of Acetone, Mark Recznik

Electronic Theses and Dissertations

Keto-enol tautomerization (KET) is a fundamental process impacting a range of molecular phenomena in organic and biochemistry. However, the accurate computation of solution-phase KET energies remains a challenge, even for prototypical acetone.

In Part I, keto-enol tautomers of acetone were incorporated into solvent clusters that interact via uninterrupted, cyclic hydrogen-bonding (UCHB) networks. An empirical model was created to predict accurate KET energies, E_taut, of simple carbonyl compounds. Based on the availability of experimental data and structural simplicity, acetone was selected as a prototype. A discrete-continuum strategy was employed – accounting simultaneously for local noncovalent interactions and bulk-phase effects …

Lipophilic Probes For Cellular Ethylene Detection, Morgan R. Brown

Electronic Theses and Dissertations

The structure of ethylene is simple, yet its biological effects are significant. When considering its role in biology it is almost exclusively regarded as a plant hormone. Research on ethylene from plants was progressed by several advancements in analytical instrumentation, from its discovery to elucidation of its signaling pathway. There is currently limited understanding of ethylene’s role in mammals, but evidence suggests that it may be a biomarker for oxidative stress! Additional tools and technology are crucial to study this surprising and important signaling role in mammals. Our group has developed molecular ethylene probes as a strategy to detect ethylene …

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 …

Isolation, Structure Elucidation, And Synthesis Of Natural Products From Marine Cyanobacteria, Keren Solomon

Electronic Theses and Dissertations

This thesis describes the isolation, structure elucidation, and synthesis of natural products from marine cyanobacteria. A crude extract from a cyanobacterium collected in Curacao showed selective affinity for the dopamine D₅ receptor in a screen against a panel of CNS receptors. Due to the high similarity of the D₅ and D₁ receptor, to date there are no known ligands that differentiate them. Attempts to purify the compound responsible for this affinity led to the isolation of the known compound caylobolide A. A second extract from a cyanobacterium collected in Panama underwent bioassay-guided fractionation and yielded the novel …

Development Towards An Ethylene Sensing Artificial Metalloenzyme, Mitchell Lee Ellinwood

Electronic Theses and Dissertations

Ethylene (ethene) is the essential ripening hormone for climacteric plants, and consequently its detection and quantification is of considerable interest to the horticulture industry. Its detection however is a non-trivial pursuit, traditionally requiring expensive and inaccessible instrumentation that fail to provide in vivo information about ethylene. A ruthenium based fluorescent probe for the selective detection of ethylene has recently been developed, and it was envisioned that this probe could be made biocompatible by encasing it within a protein scaffold making it an artificial metalloenzyme. To this end biotinylated N-heterocyclic carbenes (NHCs) were synthesized, which can be appended onto the ruthenium …

Lewis Base Promoted Annulations Of Allenoates With 1,4-Naphthoquinones, Nicole Marie Shoup

Electronic Theses and Dissertations

Lewis base promoted cyclization of allenoates with electron deficient olefins open up the possibility to generate more complex organic structures. By generating more complex molecules, we are able to produce new compounds for biomedical and material applications. Both phosphine and amine Lewis bases offer interesting annulations with allenoates resulting in Lu or Morita–Baylis–Hillman type reactions. Once the Lewis base engages with the allenoate there can be several modes of nucleophilic reactivity that allows for the allenic ester to act as a two or three carbon synthon. The allenoate can then react with varying electron deficient olefins generating more complex molecules …

Near-Infrared High Efficiency Organic Dye Sensitized Solar Cells (Dscs) And Biological Fluorescent Imaging Dyes, Yanbing Zhang

Electronic Theses and Dissertations

With the energy consumption increase every year, the non-renewable energy sources such as fossil fuels, natural gas, and coal will not sustain forever. In this case, searching for a way to develop a renewable energy source is an emergency. For decades, dye-sensitized solar cells (DSCs) have received intensive attention due to their high power conversion efficiency and low material cost. This dissertation describes efforts to design and synthesize near-infrared organic dyes to apply to two systems: first, for use in the improvement of DSCs by the optimization of electron rich components such as ullazine and cross-conjugated -bridges to increase photon-to-electricity …

Design, Synthesis, And Biological Evaluation Of Novel Polyamine Transport System Probes And Their Application To Human Cancers, Aaron Muth

Electronic Theses and Dissertations

The mammalian polyamine transport system (PTS) has been of interest due to its roles in cancer and maintaining cellular homeostasis. Polyamines are essential growth factors which are tightly controlled via a balance of biosynthesis, metabolism, import, and export. This work focused on the development and biological testing of polyamine transport probes to help understand the molecular requirements of the PTS. This was mediated through the use of a CHO (PTS active) and CHO-MG* (PTS deficient) screen, where compounds demonstrating high toxicity in CHO and low toxicity in CHO-MG* were considered PTS selective. The first chapter focused on the development of …