Chemistry Commons^™

Total Synthesis Of Ht-13-A And Ht-13-B, Total Synthesis Of Aurantioclavine, Progress Towards The Synthesis Of Cycloclavine, Yilin Zhang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Total synthesis of tetracyclic indole alkaloid ht-13-A and ht-13-B has been accomplished from commercially available (S)-4-amino-2-hydroxybutyric acid and trans4-hydroxy-L-proline respectively. The key synthetic steps include an acyliminium ion allylation, a Mitsunobu reaction, a palladium-catalyzed Stille-Kelly cross coupling reaction, and a carbon monoxide mediated palladium-catalyzed reductive Nheterocyclization. The total synthesis of aurantioclavine has been studied. The synthesis commenced with 2-amino-3-nitrophenol. Key synthetic steps include a Stille coupling reaction, a Heck reaction, a Lewis acid mediated cyclization and a carbon monoxide mediated palladium-catalyzed reductive N-heterocyclization. In addition, the first asymmetric total synthesis of (+)-cycloclavine has been studied. Key synthetic steps include a …

Molecularly Imprinted Polymers For Enantiomer Separations And Biomolecular Sensors, Britney Lyn Hebert

LSU Doctoral Dissertations

Molecularly Imprinted Polymers (MIPs) encompass a wide range of applications by changing the different components, e.g. the template, crosslinker or functional monomers. Of interest among these different applications are separations and sensors. Separations by MIPs traditionally use a chiral pure template but in some cases that chiral pure template may not be available for imprinting. Using chiral (N-α-bismethacyloyl-L-alanine) and achiral (N,O-bisacrylamide ethanolamine) crosslinkers we investigated imprinting of scalemic and racemic template mixtures of Boc-tyrosine enantiomers. The achiral and chiral crosslinkers yielded similar results for the partial separation of enantiomers by scalemic imprinted polymers because separation and recognition are not dependent …

Advanced Monte Carlo Methods For The Study Of Nucleation, Troy David Loeffler

LSU Doctoral Dissertations

The process of nucleation is an essential part of understanding and controlling phase changes in a wide array of systems. In the past theories such as Classical Nucleation Theory have been used as a tool to aid experimentalist in the study of phase mechanisms. However, recent studies have shown in detail that theories such as this are not reliable, given that it can mispredict nucleation rates by several orders of magnitude. As a result newer methodologies must be developed into order to improve upon these deficiencies. In this study we use atomistic simulations to examine the non-ideal deviations from classical …

Studies Of The Properties Of Designed Nanoparticles Using Atomic Force Microscopy, Steve Matthew Deese

LSU Doctoral Dissertations

The purpose of the research in this dissertation was to elucidate the intrinsic properties of how nanoparticles are different from bulk materials. This was done by mechanical and electronic studies of the properties of designed nanoparticles using advanced modes of atomic force microscopy. Information relating to the work functions, contact potential difference, Young’s Moduli, elasticity, and viscoelasticity can be investigated using state-of-the-art atomic force microscope (AFM) experiments. Subsurface imaging of polystyrene encapsulated cobalt nanoparticles was achieved for the first time using Force Modulation Microscopy (FMM) in conjunction with contact mode AFM. Previously prepared sample of polystyrene coated cobalt nanoparticles were …

Use Of X-Ray K-Edge Tomography And Interferometry Imaging Techniques For The Studies Of Brominated Flame Retardants, Mutairu Bolaji Olatinwo

LSU Doctoral Dissertations

The work presented in this dissertation is based on the studies of flame retardancy performance of various formulations consisting of brominated flame retardants (BFRs: Saytex 8010 and Green Armor) and their synergist, antimony trioxide (Sb2O3) in high impact polystyrene (HIPS). Chemical flame retardants are incorporated in polymers to improve their flame inhibition for optimal applications in electrical and electronic devices, furniture, printers and more. These flame retardant polymer blends are studied using the Underwriters Laboratory vertical burn test (UL 94) and X-ray imaging techniques such as X-ray K-edge absorption tomography and X-ray grating interferometry. The UL 94 burn test is …

Optimization Of Rgd Containing Cyclic Peptides Against Αvβ3 Integrin, Yan Wang, Wenwu Xiao, Yonghong Zhang, Leah Meza, Harry Tseng, Yoshikazu Takada, James B. Ames, Kit S. Lam

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

We have previously reported the use of one-bead-one-compound (OBOC) combinatorial technology to develop a disulfide cyclic, Arg-Gly-Asp containing octapeptide LXW7 (cGRGDdvc), that targets αvβ3 integrin with high affinity and specificity (Mol Cancer Ther, 9:2714–23, 2010). αvβ3 integrin is known to be over-expressed in many cancers and in tumor vasculature, and it has been established as a cancer therapeutic target. To further optimize LXW7, we have performed systematic structure activity relationship (SAR) studies. Based on the results, two highly focused OBOC peptide libraries were designed, synthesized and screened against αvβ3 integrin transfected K562 cells. One of the best …

Synthetic Efforts Towards The Synthesis Of Prostaglandin Pgf2a, Amy Marie Pollard

LSU Doctoral Dissertations

This dissertation describes strategies for synthesizing prostaglandin PGF2α. Our synthetic design creates the stereochemistry needed for the core and side chains of the target prostaglandin PGF2 alpha and PGF2 alpha synthase selective analogues while incorporating iodocyclization desymmetrization of acyclic dienes. A model system for 4-(iodomethyl)-6-methyl-1,3-dioxan-2-one was developed and synthesized for our target compound 4-(2-(benzyloxy)ethyl)-6-(iodomethyl)-5-vinyl-1,3-dioxan-2-one. Both compounds were successfully synthesized providing useful stereocenters for completing the synthesis of prostaglandin PGF2 alpha. Efforts toward total stereochemical control of PGF2α include the partial syntheses of bis-diethylanimedimethylsilane and of (4S,5S)-2-((1E,3E)-penta-1,3-dien-1-yl)-4,5-diphenyl-1,3-ditosyl-1,3,2-diazaborolidine.

Regional Effects Of Streptozotocin-Induced Diabetes On Shortening And Calcium Transport In Epicardial And Endocardial Myocytes From Rat Left Ventricle, Manal M.A. Smaill, Muhammad A. Qureshi, Anatoliy Shmygol, Murat Oz, Jaipaul Singh, Vadym Sydorenko, Alya Arabi, Frank C. Howarth, Lina Al Kury

All Works

© 2016 The Authors. In the heart, the left ventricle pumps blood at higher pressure than the right ventricle. Within the left ventricle, the electromechanical properties of ventricular cardiac myocytes vary transmurally and this may be related to the gradients of stress and strain experienced in vivo across the ventricular wall. Diabetes is also associated with alterations in hemodynamic function. The aim of this study was to investigate shortening and Ca2+ transport in epicardial (EPI) and endocardial (ENDO) left ventricular myocytes in the streptozotocin (STZ)-induced diabetic rat. Shortening, intracellular Ca2+ and L-type Ca2+ current (ICa,L) were measured by video detection, …

Bioactivity/Cytotoxicity Of Micro-/Nano-Materials And Novel Development Of Fiber-Optic Probes For Single Cell Monitoring, Qingbo Yang

Doctoral Dissertations

"Manufactured nano-/micro-materials (MNMs) have been widely used and their interactions with niche biological environment are highly concerned for both of their biohazardous and bioactive effects, whereas no available comprehensive evaluations or regulations have been provided yet. This dissertation thus focuses on three major aspects: 1) fundamental toxicity understandings of a typical MNMs (zinc oxide nanoparticles), 2) bioactivity evaluations of representative bioactive MNMs, and 3) development of novel micro-probes for high spatial resolution monitoring. Firstly, the NP's concentration, irradiation, hydrodynamic size, and the localized pH, ionic strength, NP zeta-potential as well as dissolved oxygen levels were found correlated with the production …

Ultrafast And Nonlinear Spectroscopy Of Colloidal Nanomaterials, Tony Eugene Karam

LSU Doctoral Dissertations

In the first part of this dissertation, the adsorption isotherms, resonance coupling, and fluorescence of molecular dyes on the surface of plasmonic nanoparticles are investigates. SHG is also used to investigate the growth of a silver shell on the surface of gold nanoparticles in real time. Additionally, gold-silver-gold core-shell-shell nanoparticles possess extinction peak wavelengths that can be controlled over the visible and near-infrared regions and enhanced photothermal effect. Transient absorption measurements determine that the phonon-phonon scattering lifetime is considerably faster in the core-shell-shell nanoparticles than in the gold nanospheres and gold nanorods, which contributes to the higher photothermal efficiencies. Transient …

Synthesis Of Functional Polypeptides And Development Of New Synthetic Strategies Toward Polypeptides, Jinbao Cao

LSU Doctoral Dissertations

The objective of this work is to develop a new synthetic strategy for synthesizing advanced functional polypeptides or polypeptides in general. Polypeptides are amino acids based polymers with appealing properties for different applications. One of the key challenges in polypeptide research is the synthesis of functional polypeptides under mild conditions. We developed a system based on ring-opening polymerization (ROP) of N-thiocarboxyanhydrosulfides (NTAs) to synthesize polypeptides with wide range of molecular weights under mild conditions. Owing to NTAs’ good stability, our system serves as an excellent alternative to the traditional ROP of N-carboxyanhydrides (NCA). In Chapter 1, the fundamental knowledge and …

Study Of An Active-State Cb1 Receptor Model And Jwh Compound Interactions To Predict New Emerging Synthetic Cannabinoids, Kelsey Leigh Pettus

Honors Theses

In recent years, a new class of compounds, called synthetic cannabinoids, have made their appearance in the market as a substitute for illegal marijuana or its constituent natural cannabinoids. These compounds, which are active at the same G- protein coupled receptors (GPCRS) as cannabinoids, are continuing to gain popularity because of the same cannabinoid-like effects they create. Though two cannabinoid receptors have been identified in humans, known as CB1 and CB2, synthetic cannabinoid activity at the CB1 receptor has been the focus of much research regarding synthetic cannabinoid ligand binding. In this study, the structure of the CB1 receptor is …

Magnetic Properties Of Polymeric Framework Materials With Cobalt, Cassara Higgins

Honors Program Theses

Single molecule magnets (SMM) are a new class of materials that have not been well studied. Metal-organic frameworks (MOFs) created with cobalt(II) metal centers have unpaired 3d electrons, which gives the frameworks interesting magnetic properties. Cobalt(II) nitrate centers can be linked together by varying numbers of 4,4´-bipyridine (bpy) ligands to create six different framework structures: four-coordinate 1D chain, five-coordinate 1D ladder, 2D bilayer, and 3D brick wall, and six-coordinate 2D square grid and 2D rhombic grid. The effects of framework structure and Co(II)-Co(II) distance on Weiss temperatures and μeff were investigated. By understanding which parameters of a framework has the …

Properties And Applications Of Self-Assembled Benzophenone Bis-Urea Macrocycles, Arthur Ariston Korous

Theses and Dissertations

Supramolecular chemistry is a vast multidisciplinary field with great potential and application. It is driven by one simple concept, the self-assembly of small building blocks into larger complex architectures without application of external force. This thesis highlights previous applications of supramolecular chemistry in addition to new potential properties and applications. Recently, the Shimizu group reported a self-assembled benzophenone bis-urea macrocycle (host 1) that facilitated the selective oxidation of an encapsulated alkene when UV-irradiated in an oxygen atmosphere to afford products that are typically observed in radical mediated reactions.1 Surprisingly, the host displayed a stable room temperature radical upon UV irradiation. …

Classification Of Natural Phytoplankton Populations With Fluorescence Excitation-Based Imaging Multivariate Optical Computing, Shawna Kathleen Tazik

Theses and Dissertations

Phytoplankton account for the majority of the primary productivity in the ocean and contribute significantly to the global carbon cycle through photosynthesis. A quantitative characterization of phytoplankton cell size and taxonomic composition is essential for understanding marine biogeochemical cycles, quantifying carbon export, and for predicting the ocean’s response to future climate change. Our labs have developed a new instrument for this purpose that combines fluorescence excitation spectroscopy with an all-optical approach to multivariate statistics called multivariate optical computing (MOC). The instrument, known as the Shipboard Streak Imaging Multivariate Optical Computing (SSIMOC) photometer, is a simple filter photometer that images the …

From Model Systems To Real Catalysts: Bridging The Pressure And Materials Gaps, Audrey S. Duke

Theses and Dissertations

For decades a fundamental understanding of heterogeneous catalysts has been pursued for rational catalyst design using model systems under ultrahigh vacuum (UHV) conditions; however, there exist stark differences between the simplified models investigated under UHV and the industrial catalysts used at high pressures. To bridge these gaps, it becomes essential to utilize progressively more complex materials and to correlate their surface structure and activity using incrementally higher pressure techniques. In this work, both model Pt-Re catalysts and powdered metal-organic frameworks (MOFs) were studied using a suite of traditional UHV surface science techniques in addition to ambient pressure X-ray photoelectron spectroscopy …

Synthesis And Utility Of Bis-Urea Macrocycles As Nanoreactors And As Ligands For Metal Organic Materials, Sahan R. Salpage

Theses and Dissertations

“Supramolecular chemistry” powered by non-covalent interactive forces forms the crux in the area of host-guest chemistry. Supramolecular assemblies often have different chemical and physical properties than that of its individual molecular entities and are used to develop novel functional materials. Our expertise involves making functional materials from macrocycles, which contain two urea groups and two rigid C shaped spacer groups. These individual macrocyclic components can self-assemble through hydrogen bonding and other non-covalent interactions to form porous supramolecular assemblies that can be used as confined reaction environments and as ligands to synthesize novel metal organic materials.

This dissertation focuses on studying …

Crystal Growth And Characterization Of Reduced Early Transition Metal Compounds Grown Via Hydrothermal And Molten Flux Methods, Anthony J. Cortese

Theses and Dissertations

Interest in new and facile ways to prepare early transition metal reduced oxides has recently been increasing. In the past difficult flux techniques involving vacuum furnaces, expensive metal tubing, complicated electrolytic reduction apparatuses, were used to achieve in situ reduction of fully oxidized transition metal precursors. Often times these techniques were coupled with use of a difficult flux, such as boric acid, which is hard to remove due to its insolubility in water at room temperature. These limitations can be circumvented in multiple ways, including carefully choosing a redox neutral flux, using evacuated fused silica tubes for reaction vessels, and …

Mass Spectrometry-Based Protein Profiling And Investigations Of Tgf-Ss1-Induced Epithelial-Mesenchymal Transition Signatures In Namru Murine Mammary Gland Epithelial Cells, Matsepo Ramaboli

Theses and Dissertations

Breast cancer is the second-most common cancer and the second-leading cause of cancer-related deaths in women. Despite advances in cancer early detection, prevention and treatment, breast cancer is still a major health challenge due to low survival caused by breast cancer metastasis. This warrants critical attention and intervention. From the proteomic standpoint, a protein-based multiplex system that provides large array of informative signals for cancer identification and prognosis is still limited. In this dissertation work, we developed two mass spectrometry-based strategies involving chemical biology tools for rapid protein fingerprinting of breast cancer cell lines, and for probing the O-linked N-acetylglucosamine …

Applications Of Disposable Pipette Technologies With Lc-Ms/Ms For Forensic And Clinical Analyses Of Biological Matrices, Kaylee R. Mastrianni

Theses and Dissertations

Efficiently hydrolyzing glucuronide metabolites is an important step in the analysis of drugs in urine. Amitriptyline and cyclobenzaprine are both tricyclic compounds with tertiary aliphatic amine groups that are subsequently metabolized to a less common form of glucuronide metabolite, quaternary ammonium linked glucuronides (N+- glucuronide). A collaborative study was conducted to investigate discrepancies in recoveries of these two commonly prescribed compounds in patient urine samples when hydrolyzed with different enzyme from four different commercially available β-glucuronidase sources.

Similarly, there is potential for 6-monoacetylmorphine to be converted to morphine during β-glucuronidase hydrolysis of urine samples. 6-monoacetylmorphine is a unique metabolite of …

Ligand Engineering For Advanced Functional Composite Materials, Michael H. Bell

Theses and Dissertations

The surface modification of solid inorganic substrates for thermodynamic compatibility with organic polymer media has become an important area of study for the development of advanced functional composite materials. Polymer ligands covalently bound to the substrate surface have been an effective means to achieve said compatibility. Current investigations focus on multifunctional ligand engineering where multiple chemically distinct species, each with specific functionality, can be implemented on the filler surface simultaneously. A combination of matrix compatible polymer brushes and conjugated charge trapping moieties attached to filler surfaces are investigated for enhancements in dielectric properties. Presented herein are the synthesis and characterization …

Estimation Of The Quantum Effects Of Nuclei In Large Molecular Systems, Bing Gu

Theses and Dissertations

Chemical dynamics, in principle, should be understood by solving the time-dependent Schrödinger equation for a molecular system, describing motion of the nuclei and electrons. However, the computational efforts to solve this partial second-order differential equation scales exponentially with the system size, which prevents us from getting exact numerical solutions for systems larger than 4-5 atoms. Thus, approximations simplifying the picture are necessary. The so-called Born-Oppenheimer approximation, separating motion of the electrons and nuclei is the central one: solution to the electronic Schrödinger equation defines the potential energy surface on which the nuclear motion unfolds, and there are standard quantum chemistry …

Investigating Cross Talk Between The High And Low Iron Sensors In Saccharomyces Cerevisiae, John S. Hepburn

Theses and Dissertations

Iron is essential for nearly all life on earth. Cells must maintain sufficient levels of this important nutrient due its function as a central co-factor for many cellular processes. Although iron is extremely plentiful, its poor solubility requires specialized import. On the other side, too much iron inside the cell can lead to the generation of reactive oxygen species (ROS), which have deleterious effects on many cellular functions and have been implicated in a wide variety of diseases such as cancer and Alzheimer’s disease. Using the model eukaryote Saccharomyces cerevisiae, or budding yeast, our research group has accomplished much in …

Development Of Reactions And Methods For Labeling Biomolecules In Cells, Enoch Agbesi Adogla

Theses and Dissertations

The complexity of cellular environments presents a challenge to efforts at studying and elucidating biomolecules in cells. Covalent ligation of biomolecules with fluorescent molecules that have a reactive functional group that can react with a complementary functional group on biomolecules is one way that has been utilized to study biomolecules. It enables visualization and tracking of ligation and transportation of molecules within the cell. However, the myriad of functional groups within the cell makes achieving selectivity difficult. To circumvent this problem, reactions that do not interfere with biology have been developed. These reactions, referred to as bioorthogonal reactions must be …

Cobaltocenium Containing Polymers: Complexation With Organic Anion And Initial Assesment For Anion Exchange Membranes, Mohammad Pabel Kabir

Theses and Dissertations

In this thesis, cobaltocenium containing monomers and polymers are investigated for guest anion loading and alkaline anion exchange membrane for fuel cells. The properties of these polymers are characterized and discussed.

Chapter 1 describes overall background and potential applications of metallocene and metallocenium containing polymers. The research objectives of metallocenium containing polymers are discussed.

Cobaltocenium containing polymers have potential applications in biomedical science. Therefore, the effect of different parameters such as electrostatic charge, size, conformation, π-electron system and hydrogen bonding on the interactions between these polymers and small anionic probes has been studied qualitatively, as described in Chapter 2. A …

The Development Of A Miniature Spatial Heterodyne Raman Spectrometer For Applications In Planetary Exploration And Other Extreme Environments, Patrick Doyle Barnett

Theses and Dissertations

Space exploration is arguably one of the most important endeavors our species has ever undertaken. Rapid advances in rocketry and robotics in recent years has allowed for positioning of complex scientific instruments on other planets with a precision that was previously thought impossible. This, along with the need for more sophisticated chemical measurements to achieve the goals of new, more ambitious missions and recent advances in in-situ and remote spectroscopic techniques, has led to a boom in the use of spectroscopic instruments for space exploration. However, future missions to the moons of Jupiter and Saturn, along with other planetary bodies …

Using Synthetic Lectins To Investigate Metastatic Potential In Colon Cancer, Erin E. Gatrone

Theses and Dissertations

Cancer is a disease that affects millions of people each year and it is well established that early diagnosis is a key factor towards improving survival rate, with that in mind there is a great need for better diagnostics. From the earliest onset of cancer, changes can be detected in the type and amount of carbohydrates expressed by the cancer cells, i.e., aberrant glycosylation. This process results in differing glycosylation patterns that can be used to detect cancer. Aberrant glycosylation can also greatly affect the potential of cancer cells to metastasize and can be used to stage the disease as …

Issues In Laser Induced Breakdown Spectroscopy For Measurements In The Deep Ocean And Other High-Pressure Environments, Joseph C. Bonvallet

Theses and Dissertations

This dissertation describes fundamental and applied studies that have advanced the understanding and application laser induced breakdown spectroscopy (LIBS) to the deep-ocean environment and to operation on a deep-ocean submersible. Chapter one is an overview of LIBS including a brief history, LIBS theory, the instrumentation typically used, and a specific application. Chapter two analyzes the effect that monodisperse suspended particles have on LIBS emission intensity and on the formation of a LIBS plasma. This chapter demonstrates that for particle concentrations similar to those found in the neutrally buoyant regions around hydrothermal vents there is little effect on the LIBS emission …

Atomic Oxygen Adsorption And Absorption On Rh(111) And Ag(111), Jonathan Derouin

Dissertations

A central question in the field of heterogeneous catalysis is how surface structure and subsurface species influence catalytic behavior. One key to answering that question is determining which surface structures and subsurface species are present under catalytically relevant conditions. This dissertation presents results of Auger electron spectroscopy, low energy electron diffraction, temperature programmed desorption, and scanning tunneling microscopy experiments on oxidized Rh(111) and Ag(111) crystals. Exposing Rh(111) to O2 produced a predominately (2 × 1) adlayer, but even after extended dosing, (2 × 2) domains were also present. Exposing Rh(111) to atomic oxygen yielded O coverages greater than 0.5 ML …

Development Of Folate Directed, Protein Based Photodynamic Therapy Agents, Rojenia Jones

Dissertations

To attack cancer cells in a specific manner, we have developed a folate-targeted, photodynamic therapy (PDT) agent. The folate (FA) and the chlorin e6 (Ce6) photosensitizer were attached to bovine serum albumin (BSA) using carbodiimide chemistry. Since over 50% of cancers overexpress folate receptors, FA-BSA-Ce6 can be taken up by them and is an effective PDT agent. Hela cells exposed to FA-BSA-Ce6 in the dark showed no cytotoxicity. Upon exposure to light, the conjugate was dose (time and concentration) dependent. Concentrations less than or equal to 2 µM were not effective at killing Hela cells but concentrations of at 5 …