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Synthesis And Evaluations Of “1,4-Triazolyl Combretacoumarins” And Desmethoxy Analogs, Tashrique A. Khandaker, Jessica D. Hess, Renato Aguilera, Graciela Andrei, Robert Snoeck, Dominique Schols, Padmanava Pradhan, Mahesh K. Lakshman

Publications and Research

1,4-Triazolyl combretacoumarins have been prepared by linking the trimethoxyarene unit of combretastatin A4 with coumarins, via a 1,2,3-triazole. For this, 4-azidocoumarins were accessed by a sequential two-step, one-pot reaction of 4-hydroxycoumarins with (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP), followed by reaction with NaN₃. In the reaction with BOP, a coumarin-derived phosphonium ion intermediate seems to form, leading to an O⁴-(benzotriazolyl)coumarin derivative. For the CuAAC reaction of azidocoumarins with 5-ethynyl-1,2,3-trimethoxybenzene, catalytic [(MeCN)₄Cu]PF₆ in CH₂Cl₂/MeOH with 2,6-lutidine, at 50 ^oC, was suitable. The 4-azidocoumarins were less reactive as compared to PhN₃ and …

Organic-Inorganic Hybrid Composites: Superhydrophobic Polymer Coatings With Photoreactive Perfluorinated Phthalocyanines, Abdul Azeez

Seton Hall University Dissertations and Theses (ETDs)

ABSTRACT

We report partly fluorinated and silicon-based polymers that incorporate inorganic/organic materials capable of generating reactive oxygen species (ROS) using only visible light and air. Polyvinylidene fluoride (PVDF), which incorporated a known perfluorinated phthalocyanine photosensitizer, F₆₄PcZn, supported on silicon and titanium oxides was further modified via chemical surface roughening to exhibit enhanced hydrophobicity when used as a coating. Water contact angles as high as ~159° have been observed, vs. ~ 92° for the unmodified polymer. The polymer matrix, however, does not resist the ROS it produces as evidenced by spectroscopic and SEM data. A polysiloxane matrix was similarly …

Effects Of Halogen, Chalcogen, Pnicogen, And Tetrel Bonds On Ir And Nmr Spectra, Jia Lu, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Complexes were formed pairing FX, FHY, FH₂Z, and FH₃T (X = Cl, Br, I; Y = S, Se, Te; Z = P, As, Sb; T = Si, Ge, Sn) with NH₃ in order to form an A⋯N noncovalent bond, where A refers to the central atom. Geometries, energetics, atomic charges, and spectroscopic characteristics of these complexes were evaluated via DFT calculations. In all cases, the A–F bond, which is located opposite the base and is responsible for the σ-hole on the A atom, elongates and its stretching frequency undergoes a shift to the red. This …

Development Of A Screening Method For Drugs Of Abuse By Direct Analysis Of Dried Urine Spots Coupled To Mass Spectrometry, Melanie Goldstein

Student Theses

Fast and easy screening procedures are essential in any forensic toxicology laboratory to differentiate negative samples from presumptive positive cases. Immunoassay techniques, such as enzyme multiplied immunoassay technique (EMIT), are routinely employed as screening procedures. However, these techniques lack specificity (only differentiate group of drugs and not individual compounds) and it is difficult to add new compounds to the panel. Direct analysis of dried urine spots (DUS) by mass spectrometry (MS) offers a novel strategy to overcome these issues. DUS offer an improved storage alternative for biological samples, reducing costs and space requirements. In this work, an original method to …

Elements Of An Effectiveresearch Presentation, Rachel Willand Charnley

Chemistry and Biochemistry Faculty Presentations and Other Materials

No abstract provided.

New Ideas From An Old Concept: The Hydrogen Bond, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Ongoing studies of the hydrogen bond (HB), in which a hydrogen (H) atom acts as a bridge between a pair of chemical groups, continues to offer new ideas about this interaction that have applications to biochemical processes. The ability of a proton to transfer within a HB can be controlled by conformational changes that cause small alterations to the HB geometry. The CH group, widely prevalent in biological systems, participates in HBs and contributes to the structure and stability of commonly occurring protein secondary structures such as the β-sheet. The concept of the HB has been extended to systems where …

Organically Modified Inorganic Nanoparticles For Halochromic Ionophores And Nucleic Acids, William Johnston

Doctoral Dissertations

In this dissertation, four nanoparticle reaction schemes were developed as substrates for halochromic dyes or nucleic acids. The reaction schemes include the use of two substrates: silica nanoparticles and halloysite nanotubes. The protocols can incorporate silica (SiO2) nanoparticles and halloysite aluminosilicate (AlO2SiO2) nanotubes due to the presence of silane groups on the surface of either substrate. The reaction schemes are presented along with detailed protocols which were written to facilitate both reproducibility and to serve as an aid to further study and for easy modification of the protocol to suit a researcher's needs. The data is discussed in the materials …

Violation Of Electrostatic Rules: Shifting Balance Between Pnicogen Bond And Lone Pair−Π Interaction Tuned By Substituents, Zongqing Chi, Tong Yan, Qing-Zhong Li, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Complexes were formed pairing ZCl3 (Z=P, As, Sb) with C2R4 (R= H, F, CN). The first interaction present is a pnicogen bond between the Z atom and the C=C π-bond. This bond weakens as the H atoms of ethylene are replaced by electron-withdrawing F and CN and the potential above the alkene switches from negative to positive. In the latter two cases, another set of noncovalent bonds is formed between the Cl lone pairs of ZCl3 and the π*(C=C) antibonding orbital, as well as with the F or CN substituents. The growing strength of these interactions, coupled with a large …

The Roles Of Long Noncoding Rnas In Inflammation And Immune Responses, Monira Obaid

Chemistry & Biochemistry Dissertations - Archive

Inflammation is an immune response that protects the human body from infection, illness, or injury. The inflammatory response causes the activation of immune cells, such as leukocyte subsets (i.e., monocytes, macrophages, dendritic cells, neutrophils, eosinophils and others), T cells, and B cells, and induces production of inflammatory mediators such as cytokines, chemokines, and antibodies to fight against injury or infection. Uncontrolled and continued inflammation drives the development of many human diseases, including metabolic diseases, obesity, diabetes, autoimmune disorders, neurological disorder and cancer. Indeed, the signaling process associated with inflammation and immune response is very complex. Our understanding of inflammation and …

Catalytic C-C Silylation Reactions, Thirupataiah Avullala

Chemistry & Biochemistry Dissertations - Archive

In my doctoral studies, the research is mainly focused on developing highly regio- and chemoselective C–C silylation of cyclopropanol derivatives with a hydrosilyl acetal directing group. This approach involves use of a relay of Ir-catalyzed hydrosilylation of inexpensive and readily prepared cyclopropanoacetates and Rh-catalyzed C–C silylation to achieve dioxasilolanes and dioxasilepines. In Chapter 1, we report a redox-neutral, catalytic C–C activation of cyclopropyl acetates to produce silicon-containing five-membered heterocycles in a highly regio- and chemoselective fashion. The umpolung selective silylation leading to dioxasilolanes is opposed to contemporary selective C–C functionalization protocols of cyclopropanols. Lewis base activation of dioxasilolanes as silyl …

Development Of Innovative Theranostic Platforms For Biomedical Applications, Min Kyung Khang

Chemistry & Biochemistry Dissertations - Archive

Modern technologies have been successfully identifying patient’s disease-related genetic information and developing effective drugs continuously. The discovery of molecular biomarkers paves new roads for potential individualized therapeutic applications; thus far, the call for a more development of advanced targeting/delivery platforms is highly required in the bioengineering field. Unfortunately, bioengineered targeting platforms for drug delivery at the right place, right dosage and right time have still remained in the developmental stages. To develop innovative nanosystems for various biomedical applications, polymer chemistry and click chemistry are needed to improve the function of the nanosystems. My dissertation research is based upon a unique …

Non-Heme Iron Oxygenases: An Investigation Of The Protein Ligand Effects On The Chemical Reactivity In Miae And Cysteamine Dioxygenases, Philip Palacios

Chemistry & Biochemistry Dissertations - Archive

Considerable research interest has focused on the non-heme oxygenase/oxidase enzyme family because of vast array of chemically diverse O2-depedent oxidations they participate in. For example, the bacterial multicomponent monooxygenases (sMMOH and ToMOH) are bacterial diiron enzymes that are involved in the oxidations of simple carbon sources (methane and toluene) for nutrition and other cellular cycles. Investigations of the BMM systems have significant implications for the research and development in greenhouse emissions. The hydroxylase component of the BMM superfamily is coordinated by 2-Histidine-4-carboxylate ligands (Asp or Glu) [2H4C]. The [2H4C] configuration is the typical moiety for the 2-electron oxidation in the …

Aerobic Photolysis Mecbl: Structure And Electronic Properties Of Cbl-O-O-Ch3 Intermediate., Aida Bazarganpour

Electronic Theses and Dissertations

The photolysis of methylcobalamin (coenzyme B₁₂) results in homolytic cleavage of the Co-C bond, forming cob(II)alamin and the Co(II)/CH₃ radical pair (RP) which further react with O₂ to form the intermediate (R-O-O-Cbl) that involves in the aerobic photolysis. It has been suggested that the key intermediate (R-O-O-Cbl) involves in aerobic photolysis is the insertion of O₂ between the Co-C bond. Clearly, the exposure of light is needed to induce the activation Co-C bond for generating the Co(II)/CH₃ radical pair (RP). The intermediate (R-O-O-Cbl) undergoes further decomposition to aldehyde as the final product of aerobic …

Quality Of Wheat Grains (Triticum Aestivum) Generationally Exposed To Cerium Oxide Nanoparticles (Nceo2), Oluwasegun Michael Abolade

Graduate Theses/Dissertations

The impacts of generational exposure to engineered nanomaterial on grain quality are poorly documented. This study was performed on wheat grains harvested from plants grown in soil amended with cerium oxide nanoparticles (nCeO₂) at the 2^nd and 3^rd generations. Third generation experiment was performed at low and high nitrogen (N) soil levels. The goal was to investigate changes in grain fatty acid and elemental contents due to parental exposure (C₁ vs T₁ in 2^nd generation, C₁C₂ vs T₁T₂ in 3^rd generation) or current generation …

Synthesis And Characterization Of Gd-Doped Inp/Zns Quantum Dots For Use In Multimodal Imaging Probes, Molly Erin Duszynski

Graduate Theses/Dissertations

Quantum dots (QDs), which are intensely fluorescent nanocrystals ranging 2-10 nanometers in diameter, have shown promise in fluorescence imaging. However, in vivo applications of QDs are limited due to the opaque surrounding of tissue and bones. In this study, InP/ZnS QDs were doped with a paramagnetic atom in an attempt to render them MRI-active. We have further bioconjugated these nanoprobes to develop highly specific MRI-active probes that can be used for detection of neurodegenerative diseases. These bioconjugated nanoprobes detect a mutated form of alpha-synuclein that forms oligomers that are a hallmark of Parkinson’s disease andother alpha-synucleinopathies. Here, we have optimized …

Leveraging Propargylic Frameworks In The Total Synthesis Of Natural Products Containing A 2-Aminoimidazole, Ravi P. Singh

Chemistry & Biochemistry Dissertations - Archive

Our group is mainly interested in the total synthesis of marine sponge-derived 2-aminoimidazole-containing alkaloids. A new family of 2-aminoimidazole alkaloids, the Leucetta alkaloids, is a group of >60, 2-aminoimidazole natural products found in marine sponges. Our lab is also interested in the total synthesis of oroidin-based pyrrole-imidazole containing marine sponge-derived alkaloids. These natural products are a growing class of alkaloids with exotic connectivity, unique topologies, and high nitrogen content. The presence of 2-aminoimidazole and pyrrolecarboxamide fragments in their framework represent the signature structural features. Recently, these secondary metabolites have received substantial attention because of their challenging structures and strong biological …

Synthesis Of Modified Polydiacetylene (Pda) Polymers For The Detection Of Infective Species, Shan Hazoor

Chemistry & Biochemistry Theses - Archive

Polydiacetylene (PDAs) polymers are receiving more attention as biosensors due to their ability to change absorption and fluorescence properties upon sensing various chemical and physical changes in the environment. In chapter 1, the introduction to PDA polymers have been described along with their optical properties. Diacetylene (DA) monomers can be synthesized to tune photochemical and sensing properties of PDAs. DAs self-polymerize upon UV-irradiation and show fluorescence upon stimulation. They have been reported as biological and chemical sensors, capable of visible color changes (e.g. blue to red) upon certain environmental factors such as temperature, pH changes, and upon binding with biological …

Radiolysis Of Solid-State Nitrogen Heterocycles Provides Clues To Their Abundance In The Early Solar System, Phillip G. Hammer, Ruiqin Yi, Isao Yoda, H. James Cleaves, Michael P. Callahan

Chemistry and Biochemistry Faculty Publications and Presentations

We studied the radiolysis of a wide variety of N-heterocycles, including many of biological importance, and find that the majority are remarkably stable in the solid-state when subjected to large doses of ionizing gamma radiation from a ⁶⁰Co source. Degradation of N-heterocycles as a function of dose rate and total dose was measured using high performance liquid chromatography with UV detection. Many N-heterocycles show little degradation when γ-irradiated up to a total dose of ~1 MGy, which approximates hundreds of millions of years’ worth of radiation emitted in meteorite parent bodies due to slow radionuclide decay. Extrapolation of …

Indole-3-Glycerol Phosphate Synthase Ligand Binding Interactions, Oshane Thomas

Theses, Dissertations and Culminating Projects

Indole-3-glycerol phosphate synthase (IGPS) catalyzes the irreversible ring closure of 1-(ocarboxyphenylamino)- 1-deoxyribulose 5- phosphate (CdRP) into indole-3-glycerol phosphate (IGP) during the fourth step in tryptophan biosynthesis. Analysis of the crystal structure of IGPS from Mycobacterium tuberculosis (MtIGPS) hinted the importance of Lys119 for binding or catalysis. Lys110 from sulfolobus sulfataricus IGPS (ssIGPS) that aligns with Lys119 from MtIGPS, was proposed to be a general acid for the proton transfer that initiates the ring closure and decarboxylation of CdRP. To study the importance of Lys119 in the chemical mechanism for MtIGPS, an amino acid change was made at this position to …

The Effects Of Active Site And Allosteric Residues On Catalysis And Inhibitor Selectivity In The Bacillus Stearothennophilus Dihydrofolate Reductase, Tyler Eck

Theses, Dissertations and Culminating Projects

In drug discovery, building a comprehensive picture of the binding events between a drug and its enzyme target can be useful, especially in the development of new drugs or predicting the effect of a drug on a similar target from the same protein family. It is well known that a drug's selectivity is influenced by its interactions with amino acid residues within the active site, but contributions from residues situated away from (distal to) the active site are less well understood. Using a novel predictive approach PAnPredictor that employs sequence alignments, we have previously predicted residue positions in the dihydrofolate …

Improved Sample Preparation Method For Lc-Ms/Ms Based Cellular Proteomics And Co-Immunoprecipitation Cross-Linking Proteomics Study Of Toll-Like Receptor 4, A.D.A Shahinuzzaman

Chemistry & Biochemistry Dissertations - Archive

Mass spectrometry-based methods are now widely practiced in large-scale proteomics studies. Unfortunately, sample loss in proteomics hinders complex analysis in proteomics, and immune precipitation (IP) mass spectrometry-based proteomics is getting popular in studying comprehensive signaling pathways. To contribute to these demanding research areas, I have completed two experimental projects in this thesis. In our first project, we developed a sample preparation method to identify proteins from detergent-containing cell lysate samples efficiently. Methanol-chloroform purification is an essential step in LC-MS/MS based cellular proteomics experiments since it removes salts and detergents from the sample. The cell lysis buffer contains a high concentration …

Analytical Methods For Solving Complex Problems In Food And Environmental Science, Jamie Lynn York

Chemistry & Biochemistry Dissertations - Archive

Complex samples can be challenging for analysis in a number of different ways. Food and environmental samples can be particularly difficult due to their non-uniformity from sample to sample, possible unknown contents, and complexity in terms of their number of constituents and range of abundances of different species. To overcome challenges faced with the analysis of complex samples, intricate sample handling and processing techniques need to be tailored in order to build optimal methods. These procedures can include sample preparation techniques, on-line sample clean-up, and/or tools that the instrument has to offer. Each complex sample needs to be assessed for …

Modification And Optimization Of Conducting Polymer-Modified, Redox-Magnetohydrodynamics (R-Mhd) Pumping For Enhanced And Sustained Microfluidics Applications, Md Foysal Zahid Khan

Graduate Theses and Dissertations

In this work, a novel microfluidic pumping approach, redox-magnetohydrodynamics (R-MHD) has improved by materials and device optimization to use in lab-on-a-chip applications. In R-MHD, magnetic flux (B) and ionic current density (j) interacts to generate body force (FB) in between active electrodes, according to the equation FB = j×B. This unique fluid pumping approach is scalable, tunable, generates flat flow profile, and does not require any channels or valves. Pumping performance, such as speed scales with the ionic current density (j) and duration depends on the total charge (Q). The ionic current density (j) results from the conversion of electronic …

A Foundational Study Of A New Synthetic Method Of Metal Carbonyl Clusters, Miles Shaun Millard

Boise State University Theses and Dissertations

“Traditional” Metal Carbonyl Clusters (MCCs) contain a framework of multiple metal atoms bound together through formal metal-metal (M-M) bonds. Current methods of synthesis result in different cluster sizes and lack a method to control growth. This project proposes a new method of MCC synthesis to build larger structures utilizing secondary non-covalent interactions to develop “non-traditional” MCCs. The N,N’-diarylurea moiety is a strong hydrogen bond donor/acceptor that can induce self-assembly into larger secondary structures. The union of metal carbonyl and urea chemistry provides a potential method of “non-traditional” MCC synthesis. This proof of concept experiment will elucidate foundational information such …

Enhanced Flocculation Using Drinking Water Treatment Plant Sedimentation Residual Solids, Sandhya Rao Poleneni, Enos Inniss, Honglan Shi, John Yang, Bin Hua, Joseph Clamp

Chemistry Faculty Research & Creative Works

Inefficient removal of total organic carbon (TOC) leads to the formation of carcinogenic disinfection by-products (DBPs) when a disinfectant is added. This study is performed in an effort to develop a simple, non-invasive, and cost-effective technology that will effectively lower organic precursors by having water utilities reuse their treatment residual solids. Jar tests are used to simulate drinking water treatment processes with coagulants-aluminum sulfate (alum), poly-aluminum chloride (PACl), and ferric chloride and their residual solids. Ten coagulant-to-residual (C/R) ratios are tested with water from the Missouri River at Coopers Landing in Columbia, MO versus alluvial ground waters. This treatment results …

Structural Characterization Of A Prolyl Aminodipeptidase (Pepx) From Lactobacillus Helveticus, Deanna Dahlke Ojennus

Chemistry Faculty Scholarship

Prolyl aminodipeptidase (PepX) is an enzyme that hydrolyzes peptide bonds from the N-terminus of substrates when the penultimate amino-acid residue is a proline. Prolyl peptidases are of particular interest owing to their ability to hydrolyze food allergens that contain a high percentage of proline residues. PepX from Lactobacillus helveticus was cloned and expressed in Escherichia coli as an N-terminally His-tagged recombinant construct and was crystallized by hanging-drop vapor diffusion in a phosphate buffer using PEG 3350 as a precipitant. The structure was determined at 2.0 Å resolution by molecular replacement using the structure of PepX from Lactococcus lactis (PDB entry …

Preparation, Functionalization, And/Or Characterization By X-Ray Photoelectron Spectroscopy Of Carbon Surfaces For Biosensors And Other Materials, Varun Jain

Theses and Dissertations

My dissertation is primarily divided into two parts. The first deals with the preparation, functionalization, and characterization of carbon surfaces prepared by direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS) as substrates for bioarrays. Part two discusses applications of XPS peak fitting in surface chemical analysis. Chapter 1, the introduction, includes (i) a discussion of the construction of bioarrays and the preparation of sputtered surfaces, e.g., by DCMS and HiPIMS, and also functionalization (bioconjugate) chemistry with special emphasis on the importance of covalent functionalization of surfaces, and (ii) a discussion of the surface characterization techniques and …

Using Novel Spectroscopy Tool To Study Organized Self-Assemblies, Mohammad Rafe M Bin Hatshan

Dissertations

Organized self-assemblies are the cornerstones for countless biological processes and are integral parts of lipids, proteins, carbohydrates, nucleic acids, and cell membranes. Several man-made organized assemblies also play a vital role in interdisciplinary sciences that include micelles, reverse micelles, polymers, polyelectrolytes etc. Weak chemical interactions such as hydrogen bonding, p-p stacking, hydrophilic-hydrophobic and electrostatics often result in interesting organized self-assemblies. Understanding organized self-assemblies provides a huge opportunity to mimic naturally occurring biological macromolecules, design materials and develop strategies for specific applications. Several techniques are routinely used to understand the organized self-assemblies, and optical techniques play an important role in most …

Amyloidogenicity Of Naturally Occurring Full-Length Animal Iapp Variants, Larry M. Palato, Shannon Pilcher, Alissa Oakes, Arleen Lamba, Jaris Torres, Litza I. Ledesma Monjaraz, Crystabel Munoz, Edward Njoo, Dillon J. Rinauro, Kate Alexandra Menefee, Angela Tun, Betssy L. Jauregui, Sarah Shapiro, Olivia H. Nossiff, Eileen Olivares, Kevin Chang, Viviane Nguyen, Luiza A. Nogaj, David A. Moffet

Chemistry and Biochemistry Faculty Works

Aim: To identify naturally occurring variants of IAPP capable of inhibiting the aggregation of human IAPP and protecting living cells from the toxic effects of human IAPP. Background: The loss of insulin-producing β-cells and the overall progression of type 2 diabetes appears to be linked to the formation of toxic human IAPP (hIAPP, Islet Amyloid Polypeptide, amylin) amyloid in the pancreas. Inhibiting the initial aggregation of hIAPP has the potential to slow, if not stop entirely, the loss of β-cells and halt the progression of the disease. Objective: To identify and characterize naturally occurring variants of IAPP capable of inhibiting …

Synthesis, Characterization And Biological Evaluation Of Novel (S,E)-11-[2-(Arylmethylene) Hydrazono] Pyrrolo [2,1-C] [1,4] Benzodiazepine Derivatives, David Mingle

Electronic Theses and Dissertations

Pyrrolo [2,1-c] [1,4] benzodiazepine (PBD) is a class of natural products obtained from various actinomycetes which have both anti-tumor and antibiotic activities and can bind to specific sequences of DNA. PBD-dilactam was initially produced using isatoic anhydride and (L)-proline which was then converted to the PBD-thiolactam using Lawesson's reagent. Reaction of thiolactam with hydrazine in ethanol afforded PBD-11-hydrazinyl. Condensation of 11-hydrazinyl PBD with aldehydes possessing various substitutions was performed to obtain (S,E)-11-[2-(arylmethylene) hydrazono] pyrrolo [2,1-c] [1,4] benzodiazepine derivatives. ¹HNMR, ¹³C-NMR, DEPT, IR, GC-MS and X-ray crystallography were used for the characterization. Inhibition activity of the products …