Chemistry Commons^™

New Applications Of Mass Spectrometry For Drug And Lipid Analysis, Elizabeth Lauren Emerson

Graduate Theses and Dissertations

Mass spectrometry is an important tool used in many different disciplines and settings that include forensics, drug discovery, environmental analysis, and proteomics. Gas chromatography - mass spectrometry (GC-MS) and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI - TOF MS) are two of the most important instruments used for analysis of compounds. Chapters 1 and 2 of this discussion use GC-MS for the investigation of synthetic cannabinoids in `K2' incense products and the detection of metabolites in urine samples from individuals suspected of consuming these mixtures. Analytical standards were synthesized and used for identification and confirmation of structures. Detection of …

Restricted Access Media And Methods For Making Restricted Access Media, David S. Hage, Chunling Wa, Abby Jackson, Hai Xuan

David Hage Publications

The present invention is directed to restricted access media (RAM), methods for preparing restricted access media, and kits for preparing restricted access media that contain protected ligand binding agents or protected enzymes. Certain RAM provided contain a plurality of protected regions of the Support that contain ligand binding agents that are protected by blocking agents. Certain RAM provided contain a plurality of protected regions of the support that contain unbound ligand binding agents or enzymes that are retained in the protected regions by a capping agent. Methods of making the RAM of the invention and associated kits are also provided.

The Development Of Organometallic Oboc Peptide Libraries For Use In Molecular Imaging, Dana R. Cruickshank

Electronic Thesis and Dissertation Repository

The discovery of peptide-based targeted imaging agents is hindered by the required addition of a radionuclide that can affect the binding properties of the peptide. Screening of peptide libraries is problematic because they do not take into account the presence of the imaging agent. Herein the development of an organometallic OBOC peptide library that contain a rhenium (I) tricarbonyl-based imaging entity surrogate incorporated directly onto the peptide chain, is reported. Additionally, MALDI tandem mass spectrometry is reported as a method to deconvolute organometallic peptides containing four different rhenium (I) tricarbonyl chelates on the N-terminus of octapeptides. Furthermore, an organometallic OBOC …

Breast Tumour Initiating Cell Fate Is Regulated By Microenvironmental Cues From An Extracellular Matrix, Sharmistha Saha, Pang-Kuo Lo, Xinrui Duan, Hexin Chen, Qian Wang

Faculty Publications

Cancer stem cells, also known as tumour-initiating cells (TICs), are identified as highly tumorigenic population within tumours and hypothesized to be main regulators in tumour growth, metastasis and relapse. Evidence also suggests that a tumour microenvironment plays a critical role in the development and progression of cancer, by constantly modulating cell–matrix interactions. Scientists have tried to characterize and identify the TIC population but the actual combination of extracellular components in deciphering the fate of TICs has not been explored. The basic unanswered question is the phenotypic stability of this TIC population in a tissue extracellular matrix setting. The in vivo …

Insights On Cytochrome P450 Enzymes And Inhibitors Obtained Through Qsar Studies, Jayalakshmi Sridhar, Jiawang Liu, Maryam Foroozesh, Cheryl Stevens L. Klein Stevens

Faculty and Staff Publications

The cytochrome P450 (CYP) superfamily of heme enzymes play an important role in the metabolism of a large number of endogenous and exogenous compounds, including most of the drugs currently on the market. Inhibitors of CYP enzymes have important roles in the treatment of several disease conditions such as numerous cancers and fungal infections in addition to their critical role in drug-drug interactions. Structure activity relationships (SAR), and three-dimensional quantitative structure activity relationships (3D-QSAR) represent important tools in understanding the interactions of the inhibitors with the active sites of the CYP enzymes. A comprehensive account of the QSAR studies on …

Reactions Of Methyl Perfluoroalkyl Ethers With Isopropyl Alcohol: Experimental And Theoretical Studies, Howard Knachel, Vladimir Benin, Chadwick Barklay, Janine C. Birkbeck, Billy D. Faubion, William E. Moddeman

Chemistry Faculty Publications

The reaction of an isomeric mixture of the methyl perfluoroalkyl ether, C4F9OCH3 (Novec-7100), in the presence of isopropyl alcohol (IPA) and/or water has been studied by measuring the rate of product formation using an ion-selective electrode (ISE) for fluoride ion, Karl Fisher coulometric titrations for water, and 1H and 19F NMR spectroscopy for product identification and rate studies. The results showed the methyl perfluoroalkyl ether to be very stable with products forming at the rate of ∼1 ppm per year at a laboratory temperature of 20 °C. Measurements over the temperature range of 6° to 100 °C were made on …

Discrimination Of Colon Cancer Stem Cells Using Noncanonical Amino Acid, Xinrui Duan, Honglin Li, Hexin Chen, Qian Wang

Faculty Publications

Cancer stem cells (CSCs) may be responsible for tumor recurrence. Metabolic labelling of newly synthesized proteins with non-canonical amino acids allows us to discriminate CSCs in mixed populations due to the quiescent nature of these cells.

Characterization Of Polymeric Phthalocyanine Nanoparticles Using Dynamic Light Scattering Laser, Satish Kumar Murarishetty

All Capstone Projects

The objective of this study is to use DLS (Dynamic Light Scattering) to analyze polymeric copper phthalocyanine nanoparticles (CuPcNPs). CuPcNPs are synthesized in order to facilitate drug penetration of bacterial biofilms for the treatment of chronic wounds. Microorganisms that reside inside the biofilms of chronic wounds are very resistant to any kind of treatment, even to the host’s own immune system. Therefore we have proposed an alternative method to destroy the microorganisms existing within the biofilms. Photodynamic anti-bacterial chemotherapy (PACT) has received much attention for the past decade due to the multi-drug resistant strands. PACT uses photons, a photosensitizer, and …

Design And Synthesis Studies Of New S-Adenosyl-L-Methionine Analogues, Shanshan Wu

Theses

S-Adenosyl-L-Methionine (SAM), which is involved in methyl group transfers, is the second most abundant coenzyme in the human body. It is made from adenosinetriphosphate (ATP) and methionine catalyzed by adenosyltransferase. Methyltransferases (MTs) transfer the activated methyl group from the sulfur center to a specific position in a variety of substrates, e.g., DNA, RNA, proteins, and secondary metabolites. Methyltransferases have been linked to various diseases, including cancer.

In recent years, more and more SAM analogues have been reported. These analogues show activities in biological target labeling. The purpose of this thesis is to design and synthesize new SAM analogues to inhibit …

Size Dependent Antimicrobial Properties Of Sugar Encapsulated Gold Nanoparticles, Lakshmisri Manisha Vangala

Masters Theses & Specialist Projects

The antimicrobial properties of dextrose encapsulated gold nanoparticles (dGNPs) with average diameters of 25 nm, 60 nm, and 120 nm (± 5 nm) synthesized by green chemistry principles were investigated against both Gram-negative and Gram-positive bacteria. Studies were performed involving the effect of the dGNPs on the growth, morphology and the ultrastructural properties of bacteria. dGNPs were found to have significant dose dependent antibacterial activity which was directly proportional to their size and also their concentration. The microbial assays revealed the dGNPs to be bacteriostatic as well as bactericidal. The dGNPs exhibited their bactericidal action through the disruption of the …

Synthesis And Development Of Potential Cb1 Receptor Neutral Antagonists, Kimari Slaughter

University of New Orleans Theses and Dissertations

Cannabis and its derivatives have been used for both medicinal and recreational purposes. The study of this plant led to the discovery of over 60 cannabinoids, found exclusively in cannabis, that contribute to the behavioral effects of cannabis use, the most common is delta-9-tetrahydrocannabinol. Cannabinoid receptors function to increase activity in the mesolimbic dopamine reward system. Dopamine is a neurotransmitter that plays a major role in addition and its regulation plays a crucial role in mental and physical well-being. There is evidence that CB₁ receptors are important to the reinforcing effects and the development of physical dependence on opiate …

Synthesis Of S-Ribosyl-L-Homocysteine And Analogs Modified At The Homocysteine-C3 Position, Ruoyi Liu

Master's Theses

Quorum sensing (QS) is a process of bacterial cell-to-cell communication that conveys population density information in order to coordinate gene expression to produce synchronized behaviors. QS regulates the expression of virulence genes in many species of bacteria; hence, the manipulation of QS pathways may lead to treatment options against many bacterial diseases. The LuxS enzyme converts S-ribosyl-L-homocysteine (SRH) into homocysteine (HCys) and 4(S),5-dihydroxypentane-2,3-dione (DPD), which is the precursor of autoinducer-2 (AI-2). Thus, inhibitors of LuxS could prevent QS by halting the conversion of SRH to AI-2 rendering the cell “uncommunicative”. This work shows the successful chemical synthesis …

Synthesis And Biological Evaluation Of Rigid Analogues Of Methamphetamines, Andrea N. Forsyth

University of New Orleans Theses and Dissertations

A series of rigid azetidenyl-based methamphetamine analogs were synthesized from commercially available N-Boc-azetidinone. The benzylideneazetidine analogs were prepared via a Wittig olefination via the ylides generated from the corresponding triphenylphosphonium benzylhalide salts. The substituted benzylazetidine analogs were synthesized from the corresponding benzylideneazetidienes via hydrogention over palladium and platinum catalysts. The benzylideneazetidine and benzyliazetidine analogs were evaluated at monoamine transporters as a part of preliminary structure-activity study for the development of novel monoamine transporter ligands. The binding affinities of the azetidine analogs were determined at dopamine (DAT) and serotonin (SERT) transporters in rat brain tissue preparations. The preliminary in vitro …

Interaction Of Pharmaceutical Compounds With Dissolved Organic Matter, Carlen Nigl Smith

Honors Theses

Highly prescribed pharmaceutical compounds and their metabolites used to treat conditions ranging from infections to depression are of environmental concern as these excreted compounds are increasingly appearing in wastewater influent. As pharmaceuticals enter treatment plants they also can interact with dissolved organic matter (DOM) present. This potential interaction between pharmaceutical compounds and DOM may inhibit the advanced oxidation process (AOP) based removal of drugs during water treatment. The focus of this research was to utilize multinuclear magnetic resonance and hydroxyl radical kinetics to assess whether an interaction between influent pharmaceuticals and DOM does occur, the extent of the interaction, and …

Mesoionic Compounds, Mark Gordon

Student Scholarship – Chemistry

A poster presentation defining what mesoionic compounds are, describing their uses in the medical field and beyond, and providing examples of common mesoionic compounds.

Identification And Analysis Of Stereoselective Drug Interactions With Low Density Lipoprotein By High-Performance Affinity Chromatography, Matt Sobansky, David S. Hage

Chemistry Department: Faculty Publications

Columns containing immobilized low density lipoprotein (LDL) were prepared for the analysis of drug interactions with this agent by high-performance affinity chromatography (HPAC). R/SPropranolol was used as a model drug for this study. The LDL columns gave reproducible binding to propranolol over 60 h of continuous use in the presence of pH 7.4, 0.067 M potassium phosphate buffer. Experiments conducted with this type of column through frontal analysis indicated that two types of interactions were occurring between R-propranolol and LDL, while only a single type of interaction was observed between S-propranolol and LDL. The first type …

Reversed Chloroquine Molecules As A Strategy To Overcome Resistance In Malaria, David H. Peyton

Chemistry Faculty Publications and Presentations

This short review tells the story of how Reversed Chloroquine drugs (RCQs) were developed. These are hybrid molecules, made by combining the quinoline nucleus from chloroquine (CQ) with moieties which are designed to inhibit efflux via known transporters in the membrane of the digestive vacuole of the malaria parasite. The resulting RCQ drugs can have potencies exceeding that of CQ, while at the same time having physical chemical characteristics that may make them favorable as partner drugs in combination therapies. The need for such novel antimalarial drugs will continue for the foreseeable future.

Unusual Activities Of The Thioesterase Domain For The Biosynthesis Of The Polycyclic Tetramate Macrolactam Hsaf In Lysobacter Enzymogenes C3, Lili Lou, Haotong Chen, Ronald Cerny, Yaoyao Li, Yuemao Shen, Liangcheng Du

Ronald Cerny Publications

HSAF is an antifungal natural product with a new mode of action. A rare bacterial iterative PKSNRPS assembles the HSAF skeleton. The biochemical characterization of the NRPS revealed that the thioesterase (TE) domain possesses the activities of both a protease and a peptide ligase. Active site mutagenesis, circular dichroism spectra and homology modeling of the TE structure suggested that the TE may possess uncommon features that may lead to the unusual activities. The iterative PKS-NRPS is found in all polycyclic tetramate macrolactam gene clusters, and the unusual activities of the TE may be common to this type of hybrid PKS-NRPS.

Ccpa Regulates Arginine Biosynthesis In Staphylococcus Aureus Through Repression Of Proline Catabolism, Austin S. Nuxoll, Steven M. Halouska, Marat R. Sadykov, Mark L. Hanke, Kenneth W. Bayles, Tammy Kielian, Robert Powers, Paul D. Fey

Chemistry Department: Faculty Publications

Staphylococcus aureus is a leading cause of community-associated and nosocomial infections. Imperative to the success of S. aureus is the ability to adapt and utilize nutrients that are readily available. Genomic sequencing suggests that S. aureus has the genes required for synthesis of all twenty amino acids. However, in vitro experimentation demonstrates that staphylococci have multiple amino acid auxotrophies, including arginine. Although S. aureus possesses the highly conserved anabolic pathway that synthesizes arginine via glutamate, we demonstrate here that inactivation of ccpA facilitates the synthesis of arginine via the urea cycle utilizing proline as a substrate. Mutations within putA, rocD, …

Crystalline Nano Structures, Barry Chin Li Cheung, Joseph Reese Brewer, Nirmalendu Deo

Chemistry Department: Faculty Publications

The present invention comprises nano obelisks and nanostructures and methods and processes for same. The nano obelisks of the present invention are advantageous structures for use as electron source emitters. For example, the ultra sharp obelisks can be used as an emitter source to generate highly coherent and high energy electrons with high current.

Polymers Used In Medicine: Common Types And Benefits Of Drug Delivery Systems, Camille Andrews

Natural Sciences Student Research Presentations

This poster describes the common types and benefits of drug delivery systems.

Butylated Hydroxytoluene Analogs: Synthesis And Evaluation Of Their Multipotent Antioxidant Activities, Azhar Ariffin

Azhar Ariffin

A computer-aided predictions of antioxidant activities were performed with the Prediction Activity Spectra of Substances (PASS) program. Antioxidant activity of compounds 1, 3, 4 and 5 were studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and lipid peroxidation assays to verify the predictions obtained by the PASS program. Compounds 3 and 5 showed more inhibition of DPPH stable free radical at 10(-4) M than the well-known standard antioxidant, butylated hydroxytoluene (BHT). Compound 5 exhibited promising in vitro inhibition of Fe2+-induced lipid peroxidation of the essential egg yolk as a lipid-rich medium (83.99%, IC50 16.07 +/- 3.51 mu M/mL) compared to alpha-tocopherol (alpha-TOH, 84.6%, IC50 …

The Use Of A Ditopic Gd(Iii) Paramagnetic Probe For Investigating Α-Bungarotoxin Surface Accessibility, Andrea Bernini, Ottavia Spiga, Vincenzo Venditti, Filippo Prischi, Mauro Botta, Gianluca Croce, Angela Pui-Ling Tong, Wing-Talk Wong, Neri Niccolai

Vincenzo Venditti

Protein surface accessibility is a critical parameter which drives all intermolecular interaction processes. In this respect a big deal of information has been derived by analyzing paramagnetic perturbation profiles obtained from NMR protein spectra, particularly in the case that the effects due to different soluble paramagnets can be compared. Here Gd2L7, a neutral ditopic paramagnetic NMR probe, has been characterized in terms of structure and relaxivity and its paramagnetic perturbations on α-bungarotoxin CαH signals in 1H–13C HSQC (heteronuclear single quantum coherence) spectra have been analyzed. Then, these signal attenuations have been compared with the ones previously obtained in the presence …

An Efficient Protocol For Incorporation Of An Unnatural Amino Acid In Perdeuterated Recombinant Proteins Using Glucose-Based Media, Vincenzo Venditti, Nicolas L. Fawzi, G. Marius Clore

Vincenzo Venditti

The in vivo incorporation of unnatural amino acids into proteins is a well-established technique requiring an orthogonal tRNA/aminoacyl-tRNA synthetase pair specific for the unnatural amino acid that is incorporated at a position encoded by a TAG amber codon. Although this technology provides unique opportunities to engineer protein structures, poor protein yields are usually obtained in deuterated media, hampering its application in the protein NMR field. Here, we describe a novel protocol for incorporating unnatural amino acids into fully deuterated proteins using glucose-based media (which are relevant to the production, for example, of amino acid-specific methyl-labeled proteins used in the study …

Conformational Selection And Substrate Binding Regulate The Monomer/Dimer Equilibrium Of The C-Terminal Domain Of Escherichia Coli Enzyme I, Vincenzo Venditti, G. Marius Clore

Vincenzo Venditti

The bacterial phosphotransferase system (PTS) is a signal transduction pathway that couples phosphoryl transfer to active sugar transport across the cell membrane. The PTS is initiated by the binding of phosphoenolpyruvate (PEP) to the C-terminal domain (EIC) of enzyme I (EI), a highly conserved protein that is common to all sugar branches of the PTS. EIC exists in a dynamic monomer/dimer equilibrium that is modulated by ligand binding and is thought to regulate the overall PTS. Isolation of EIC has proven challenging, and conformational dynamics within the EIC domain during the catalytic cycle are still largely unknown. Here, we present …

Materials For Diabetes Therapeutics, Kaitlin M. Bratlie, Roger L. York, Michael A. Invernale, Robert Langer, Daniel G. Anderson

Kaitlin M. Bratlie

This review is focused on the materials and methods used to fabricate closedloop systems for type 1 diabetes therapy. Herein, we give a brief overview of current methods used for patient care and discuss two types of possible treatments and the materials used for these therapies-(i) artificial pancreases, comprised of insulin producing cells embedded in a polymeric biomaterial, and (ii) totally synthetic pancreases formulated by integrating continuous glucose monitors with controlled insulin release through degradable polymers and glucose-responsive polymer systems. Both the artificial and the completely synthetic pancreas have two major design requirements: the device must be both biocompatible and …

From Cox-2 Inhibitor Nimesulide To Potent Anti-Cancer Agent: Synthesis, In Vitro, In Vivo And Pharmacokinetic Evaluation, Bo Zhong, Xiaohan Cai, Snigdha Chennamaneni, Xin Yi, Lili Liu, John J. Pink, Afshin Dowlati, Yan Xu, Aimin Zhou, Bin Su

Chemistry Faculty Publications

Cyclooxygenase-2 (COX-2) inhibitor nimesulide inhibits the proliferation of various types of cancer cells mainly via COX-2 independent mechanisms, which makes it a good lead compound for anti-cancer drug development. In the presented study, a series of new nimesulide analogs were synthesized based on the structure–function analysis generated previously. Some of them displayed very potent anti-cancer activity with IC50s around 100 nM–200 nM to inhibit SKBR-3 breast cancer cell growth. CSUOH0901 (NSC751382) from the compound library also inhibits the growth of the 60 cancer cell lines used at National Cancer Institute Developmental therapeutics Program (NCIDTP) with IC50s around 100 nM–500 nM. …

Incorporation Of The Actin-Myosin Biomolecular Motor System Into A Microfluidic Device, Rebecca Marie Ragland

Theses, Dissertations and Capstones

Recently, the field of bionanotechnology has sought to develop a device containing a biomolecular motor nano-cargo transport system. Among many applications, a device of this sort could be used to sort, purify, or detect specific molecules. In this work, an attempt was made to incorporate the actin-myosin biomolecular motor system into a microfluidic device constructed out of polydimethylsiloxane (PDMS) and glass. Methods for cleaning and functionalizing the glass surface of the device were optimized. After performing actin-myosin motility assays in a variety of PDMS/glass devices, it was determined that the oxygen permeability of PDMS limited the quality of motility that …

Unraveling The Structural Complexity In A Single-Stranded Rna Tail: Implications For Efficient Ligand Binding In The Prequeuosine Riboswitch, Catherine D. Eichhorn, Jun Feng, Krishna C. Suddala, Nils G. Walter, Charles L. Brooks Iii, Hashim M. Al-Hashimi

Chemistry Department: Faculty Publications

Single-stranded RNAs (ssRNAs) are ubiquitous RNA elements that serve diverse functional roles. Much of our understanding of ssRNA conformational behavior is limited to structures in which ssRNA directly engages in tertiary interactions or is recognized by proteins. Little is known about the structural and dynamic behavior of free ssRNAs at atomic resolution. Here, we report the collaborative application of nuclear magnetic resonance (NMR) and replica exchange molecular dynamics (REMD) simulations to characterize the 12 nt ssRNA tail derived from the prequeuosine riboswitch. NMR carbon spin relaxation data and residual dipolar coupling measurements reveal a flexible yet stacked core adopting an …

Nucleic-Acid Based Lateral Flow Strip Biosensor Via Competitive Binding For Possible Dengue Detection, Erwin P. Enriquez, Henson L. Lee Yu, Christine Marie Montesa, Nina Rosario L. Rojas

Chemistry Faculty Publications

A low-cost, simple, rapid and selective nucleic-acid based lateral flow strip biosensor (LFSB) for possible dengue viral RNA detection is described in this study. The detection is based on competitive binding, where gold nanoparticles (AuNPs), with average size of ~10 nm confirmed using UV-Vis, TEM and AFM images, are used as visualizing agents. These are bioconjugated with DNA which competitively binds with its complementary strand either in the sample or in the test line of the LFSB. The detection scheme reduces the number of probes which effectively lowers the cost for the design of the test strip. The whole test …