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Design And Development Of Chiral And Achiral Molecularly Imprinted Stationary Phases, Jason Paul Lejeune

LSU Doctoral Dissertations

Although the cross-linker can comprise over 80% of the polymer composition, improving the nature of the cross-linker in molecularly imprinted polymers has not been studied extensively. The goal of this research is to develop novel cross-linking monomers to either use in the One MoNomer Molecularly Imprinted Polymer system (OMNiMIP) or use in conjunction with other commercially available cross-linkers and functional monomers. Chapter 2 contains research into the understanding of the performance of a new cross-linking monomer (N, O - bismethacryloyl ethanolamine, NOBE) discovered in the Spivak Research Group. The ability of this monomer to outperform traditional two monomer systems in …

Nmr Investigations Of Biomass-To-Fuel Conversions By Hydrothermal Processes, Wenjia Zhang

Doctoral Dissertations

"Biofuels have gained significant attention as the most promising alternative energy and fuel supply for the near future because of two dominant reasons: first, biofuels are environmentally friendly; and second, they afford a sustainable technology. Biofuels can be synthesized from biomass by several different processes, among which, hydrothermal conversion is considered to be more energy efficient. However, scientific efforts to improve hydrothermal biomass-to-fuel (HT-BTF) conversion efficiencies are severely limited because little is known about the salient reaction mechanisms and intermediates. This study is aimed at a better understanding of the hydrothermal biomass degradation kinetics by advanced NMR spectroscopy and, accordingly, …

Discovery And Identification Of New Dna Photoproducts And Investigation Of The Redox Mechanism Of Human Apurinic/Apyrimidinic Endonuclease 1 (Hape1) Protein, Dian Su

All Theses and Dissertations (ETDs)

Exposure of cells to ultraviolet light results in the formation of DNA photoproducts, many of which have been linked to skin cancer. The majority of these photoproducts arise from a photoreaction between two pyrimidines. Irradiation of double stranded B form DNA under physiological conditions mainly produces adjacent dimers. Nonadjacent photodimers of both intrastrand and interstrand types are much rarer. Intrastrand-type nonadjacent dimers form when one or more nucleotides between two pyrimidines become extrahelical owing to the formation of single strand DNA or a slipped structure. This allows the two pyrimidines to photodimerize in a colinear arrangement, as if the intervening …

Stability Of Spore-Based Sensing Systems, Abhishek Sangal

University of Kentucky Master's Theses

The full exploitation of bacterial whole-cell biosensing systems in field applications requires the survival of bacterial cells and long term-preservation of their sensing ability during transportation and on-site storage of such analytical systems. Specifically, there is a need for rapid, simple and inexpensive biosensing systems for monitoring human health and the environment in remote areas which often suffer from harsh atmospheric conditions and inadequate commercial distribution and storage facilities. Our laboratory has previously reported the successful use of bacterial spores as vehicles for the long-term preservation and storage of whole-cell biosensing systems at room temperature.

In the present research, we …

Synthesis, Characterization And Development Of Catalysts For Co2 Capture, Anitha Suhas Wishrojwar

University of Kentucky Master's Theses

Fossil fuel and advanced industrialization techniques contribute to global warming through emissions of greenhouse gases such as CO₂. In order to mitigate climate change, there is a desperate need to reduce CO₂ emissions from different sources. CO₂ capture and sequestration (CCS) play an important role in these reductions.

Naturally occurring enzymes, e.g., carbonic anhydrase (CA), can catalyze these reactions in living systems. Much effort has been focused on complexes of zinc with ligands such as teta, cyclen and tripodal ligands including BIMA and Trispyrazolylborates. These complexes have many interesting CO₂ capture properties, but maintain toxic …

Photodissociation Dynamics In Titan's Atmosphere, Welvidanalage Ruchira Silva

Wayne State University Dissertations

Photodissociation dynamics of molecules relevant to understanding Titan's atmosphere (diacetylene, cyanoacetylene and heptane isomers) are carried out under collisionless condition using the DC slice imaging technique. In diacetylene photodissociation, two-photon processes dominate at 243 nm and 212 nm whereas at 121.6 nm, a one-photon dissociation process dominates. Direct measurement of the lifetime of metastable triplet diacetylene confirms sub-microsecond lifetimes. Photodissociation of cyanoacetylene at 193.3 nm proceeds on the S1 potential energy surface with an exit barrier. In heptane photodissociation, the dissociation occurs on the ground state or low-lying triplet states with nonradiative electronic relaxation. Time-of-flight mass spectroscopy studies in this …

Total Synthesis Of 2-Aminoimidazole Alkaloids From Leucetta And Clathrina Sponges, Panduka B. Koswatta

Chemistry & Biochemistry Dissertations - Archive

Sponges of the major class, Calcarea can be found in nearly all marine habitats. Two Calcarea genera, Leucetta and Clathrina have found be rich with 2-aminoimidazole alkaloids. The first alkaloid of these groups was isolated in 1987 from a bright yellow sponge of the class Calcispongiae (calcarea) and Leucetta chagosensis dendy (Leucetta) collected near Na'ama in the Gulf of Eilat (Aqaba) in the Red Sea. The nomenclature for this whole series of compounds is based on the location of the initial source material. The first Chapter describes the isolation, biological activities, possible biosyntheses and total synthesis of these alkaloids. The …

Polarization Dependent Two-Photon Absorption Properties Of Chiral Molecules, Carlos Toro

Electronic Theses and Dissertations

Molecules that are non-superimposable on their mirror image are named chiral or optically active compound. Over the years, molecular chirality has played an essential role in the understanding of fundamental aspects associated the origin of life, drug and food technologies and, asymmetric catalysis, among others. Moreover, most of the groundbreaking discoveries and advances made in this field have happened due to the development of spectroscopic techniques based on the natural asymmetry of the enantiomers and their ability to preferentially absorb right or left polarized light. For instance, circular dichroism (CD), which measures the difference in absorption between these two states …

Effluent Organic Nitrogen (Eon): Bioavailability And Photochemical And Salinity-Mediated Release, Deborah A. Bronk, Quinn N. Roberts, Marta P. Sanderson, Elizabeth A. Canuel, Patrick G. Hatcher, Rajaa Mesfioui, Katherine C. Filippino, Margaret R. Mulholland, Nancy G. Love

Chemistry & Biochemistry Faculty Publications

The goal of this study was to investigate three potential ways that the soluble organic nitrogen (N) fraction of wastewater treatment plant (WWTP) effluents, termed effluent organic N (EON), could contribute to coastal eutrophication - direct biological removal, photochemical release of labile compounds, and salinity-mediated release of ammonium (NH₄+). Effluents from two WWTPs were used in the experiments. For the bioassays, EON was added to water from four salinities (∼0 to 30) collected from the James River (VA) in August 2008, and then concentrations of N and phosphorus compounds were measured periodically over 48 h. Bioassay results, based …

Sequence And Structural Analysis Of The Chitinase Insertion Domain Reveals Two Conserved Motifs Involved In Chitin Binding, Hai Li, Lesley H. Greene

Chemistry & Biochemistry Faculty Publications

Background: Chitinases are prevalent in life and are found in species including archaea, bacteria, fungi, plants, and animals. They break down chitin, which is the second most abundant carbohydrate in nature after cellulose. Hence, they are important for maintaining a balance between carbon and nitrogen trapped as insoluble chitin in biomass. Chitinases are classified into two families, 18 and 19 glycoside hydrolases. In addition to a catalytic domain, which is a triosephosphate isomerase barrel, many family 18 chitinases contain another module, i.e., chitinase insertion domain. While numerous studies focus on the biological role of the catalytic domain in chitinase activity, …

Molecular Dynamics Studies Of Simple Model Fluids And Water Confined In Carbon Nanotube, Jun Wang

Department of Chemistry: Dissertations, Theses, and Student Research

Molecular Dynamics (MD) simulation is one of the most important computational techniques with broad applications in physics, chemistry, chemical engineering, materials design and biological science. Traditional computational chemistry refers to quantum calculations based on solving Schrodinger equations. Later developed Density Functional Theory (DFT) based on solving Kohn-Sham equations became the more popular ab initio calculation technique which could deal with ~1000 atoms by explicitly considering electron interactions. In contrast, MD simulation based on solving classical mechanics equations of motion is a totally different technique in the field of computational chemistry. Electron interactions were implicitly included in the empirical atom-based potential …

Major Challenges For The Modern Chemistry In Particular And Science In General, Vuk Uskoković

Pharmacy Faculty Articles and Research

In the past few hundred years, science has exerted an enormous influence on the way the world appears to human observers. Despite phenomenal accomplishments of science, science nowadays faces numerous challenges that threaten its continued success. As scientific inventions become embedded within human societies, the challenges are further multiplied. In this critical review, some of the critical challenges for the field of modern chemistry are discussed, including: (a) interlinking theoretical knowledge and experimental approaches; (b) implementing the principles of sustainability at the roots of the chemical design; (c) defining science from a philosophical perspective that acknowledges both pragmatic and realistic …

Novel Improvements On The Analytical Chemistry Of Polycyclic Aromatic Hydrocarbons And Their Metabolites, Wang Huiyong

Electronic Theses and Dissertations

Polycyclic aromatic hydrocarbons (PAH) are important environmental pollutants originating from a wide variety of natural and anthropogenic sources. Because many of them are highly suspect as etiological agents in human cancer, chemical analysis of PAH is of great environmental and toxicological importance. Current methodology for PAH follows the classical pattern of sample preparation and chromatographic analysis. Sample preparation preconcentrates PAH, simplifies matrix composition, and facilitates analytical resolution in the chromatographic column. Among the several approaches that exist to pre-concentrate PAH from water samples, the Environmental Protection Agency (EPA) recommends the use of solid-phase extraction (SPE). High-performance liquid chromatography (HPLC) and …

Fabrication Of Functional Nanostructures Using Polyelectrolyte Nanocomposites And Reduced Graphene Oxide Assemblies, Anindarupa Chunder

Electronic Theses and Dissertations

A wide variety of nanomaterials ranging from polymer assemblies to organic and inorganic nanostructures (particles, wires, rods etc) have been actively pursued in recent years for various applications. The synthesis route of these nanomaterials had been driven through two fundamental approaches - 'Top down' and 'Bottom up'. The key aspect of their application remained in the ability to make the nanomaterials suitable for targeted location by manipulating their structure and functionalizing with active target groups. Functional nanomaterials like polyelectrolyte based multilayered thin films, nanofibres and graphene based composite materials are highlighted in the current research. Multilayer thin films were fabricated …

Simulation Of Photochromic Compounds Using Density Functional Theory Methods, Pansy Patel

Electronic Theses and Dissertations

This Thesis describes the systematic theoretical study aimed at prediction of the essential properties for the functional organic molecules that belong to diarylethene (DA) family of compounds. Diarylethenes present the distinct ability to change color under the influence of light, known as photochromism. This change is due to ultrafast chemical transition from open to closed ring isomers (photocyclization). It can be used for optical data storage, photoswitching, and other photonic applications. In this work we apply Density Functional Theory methods to predict 6 of the related properties: (i) molecular geometry; (ii) resonant wavelength; (iii) thermal stability; (iv) fatigue resistance; (v) …

Dft Study Of Geometry And Energetics Of Transition Metal Systems, Satyender Goel

Electronic Theses and Dissertations

This dissertation focuses on computational study of the geometry and energetics small molecules and nanoclusters involving transition metals (TM). These clusters may be used for various industrial applications including catalysis and photonics. Specifically, in this work we have studied hydrides and carbides of 3d-transition metal systems (Sc through Cu), small nickel and gold clusters. Qualitatively correct description of the bond dissociation is ensured by allowing the spatial and spin symmetry to break. We have tested applicability of new exchange-correlation functional and alternative theoretical descriptions (spin-contamination correction in broken symmetry DFT and ensemble Kohn-Sham (EKS)) as well. We studies TM hydrides …

Hydrophobic Silicas With Well-Defined Chemistry And Geometry: Synthesis, Adsorption, And Interfacial Properties, Francis Bernardoni

Seton Hall University Dissertations and Theses (ETDs)

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A Parallel Non-Alignment Based Approach To Efficient Sequence Comparison Using Longest Common Subsequences, Sanjukta Bhowmick, Mohammad Shafiullah, H. Rai, Dhundy Raj Bastola

Chemistry Faculty Publications

Biological sequence comparison programs have revolutionized the practice of biochemistry, and molecular and evolutionary biology. Pairwise comparison of genomic sequences is a popular method of choice for analyzing genetic sequence data. However the quality of results from most sequence comparison methods are significantly affected by small perturbations in the data and furthermore, there is a dearth of computational tools to compare sequences beyond a certain length. In this paper, we describe a parallel algorithm for comparing genetic sequences using an alignment free-method based on computing the Longest Common Subsequence (LCS) between genetic sequences. We validate the quality of our results …

Alternative Splicing And Polyadenylation Contribute To The Generation Of Herg1 C-Terminal Isoforms, Qiuming Gong, Matthew R. Stump, A. Russell Dunn, Vivianne Deng, Zhengfeng Zhou

Faculty Publications - Department of Biological & Molecular Science

The human ether-a-go-go-related gene 1 (hERG1) encodes the pore-forming subunit of the rapidly activating delayed rectifier potassium channel. Several hERG1 isoforms with different N- and C-terminal ends have been identified. The hERG1a, hERG1b, and hERG1-3.1 isoforms contain the full-length C terminus, whereas the hERG1_USOisoforms, hERG1a_USO and hERG1b_USO, lack most of the C-terminal domain and contain a unique C-terminal end. The mechanisms underlying the generation of hERG1_USOisoforms are not understood. We show that hERG1 isoforms with different C-terminal ends are generated by alternative splicing and polyadenylation of hERG1 pre-mRNA. We identified an …

Dynamic Path Bifurcation For The Beckmann Reaction: Observation And Implication, H. Yamataka, M. Sato, H. Hasegawa, Salai Cheettu Ammal

Faculty Publications

The reaction of oximes to amides, known as the Beckmann rearrangement, may undergo fragmentation to form carbocations + nitriles instead of amides when the cations have reasonable stability. The reactions of oxime derivatives of 1-substituted-phenyl-2-propanones and 3-substituted-phenyl-2-butanones in aqueous solvents gave both rearrangement and fragmentation products, the ratio of which was dependent on substituents. Transition state (TS) optimizations and intrinsic reaction coordinate (IRC) calculations for the reaction of 1-phenyl-2-propanone oximes showed that there is a single TS for each substituted compound. The IRC path from the TS either led to a rearrangement product or a fragmentation product depending on the …

Water Analysis For Emerging Environmental Contaminants, Xiaoliang Cheng

Masters Theses

"The presence of emerging environmental contaminants in water bodies used either as drinking water or for recreational purpose has received considerable attention in the recent years. The emerging environmental contaminants can be defined as a wide range of chemicals that have been determined in the environment which may present serious health risks for humans. The occurrence of these contaminants indicate that both household and industrial chemicals have been introduced to water resources, a wide variety of chemicals, such as disinfection byproducts, pharmaceutical and personal care products and so on, have been detected at cetiain levels in either water bodies or …

The Antioxidant Properties Of Whey Permeate Treated Fresh-Cut Tomatoes, Lubna Ahmed, Ana Belen Martin-Diana, Daniel Rico, Catherine Barry-Ryan

Articles

The aim of this research was to analyse the effects of three types of cheese whey permeate treatment on the antioxidant properties of fresh-cut tomatoes. Tomatoes were treated with whey permeate concentrate (PC), delactosed permeate (DP) and delactosed concentrate (DC), stored at 4 C for 10 days and compared to samples treated with the industry standard, chlorine (120 ppm). Samples treated with DP retained significantly higher antioxidant activity (FRAP) and total phenols (TP), when compared with those treated with PC and DC. DP showed significantly higher results than chlorine for DPPH, FRAP and TP. In DPPH assay, all whey permeate-treated …

S-Nitrosothiols: Formation, Decomposition, Reactivity And Possible Physiological Effects, Moshood Kayode Morakinyo

Dissertations and Theses

Three biologically-active aminothiols cysteamine (CA), DL-cysteine (CYSH) and DL-homocysteine, were studied in this thesis. These aminothiols react with nitrous acid (HNO₂), prepared in situ, to produce S-nitrosothiols (RSNOs): S-nitrosocyteamine (CANO), S-nitrosocysteine (CYSNO) and S-nitrosohomocysteine (HCYSNO). They also react with S-nitrosoglutathione (GSNO) and S-nitroso-N-acetylpenicillamine (SNAP) through a transnitrosation reaction to produce their corresponding RSNOs. A detailed kinetics and mechanistic study on the formation of these RSNOs and their subsequent decomposition to release nitric oxide (NO) were studied.

For all three aminothiols the stoichiometry of their reaction with nitrous acid is strictly 1:1 with the formation of one mole …

Radical Scavenging Potential Of Compounds Isolated From Vitex Agnus-Castus, . Azizuddin, Talat Makhmoor, Muhammad Iqbal Choudhary

Turkish Journal of Chemistry

Nine secondary metabolites-artemetin (1), casticin (2), 3-hydroxy-5,6,7,4'-tetramethoxy flavone U(3), penduletin (4), p-hydroxybenzoic acid (5), methyl 3,4-dihydroxybenzoate (6), methyl isovanillate (7), vanillic acid (8), and 3,4-dihydroxybenzoic acid (9)-were isolated from a folkloric medicinal plant, Vitex agnus-castus. The structures of compounds 1-9 were identified using spectroscopic techniques. Compound 7 was isolated for the first time from this plant. These compounds were screened for their antioxidant activity. Compounds 6 and 9 exhibited significant activity against the DPPH free radical.

Template Synthesis And Characterization Of 16-Membered Octaazamacrocyclic Complexes: A Photoelectron Spectroscopic Study, Abul Kalam, Vishnu Tripathi, Shekhar Srivastava, Yogesh Pandey, Anil Kumar, Alok Gupta, Sharat Srivastava, Ankoor Purohit

Turkish Journal of Chemistry

A novel series of complexes of the type [MLX_2] where M= Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); X= C^- or NO_3^- were synthesized by template condensation of hydrazine hydrate, acetaldehyde, 2,4-pentanedione, and thiocarbohydrazide in the presence of divalent metal salt in methanolic solution. The complexes were characterized with the help of elemental analysis, conductance measurements, magnetic measurements, electronic, NMR, XPS, and infrared and far infrared spectral studies. Electronic spectra along with magnetic moments suggest 6-coordinated octahedral geometry for these complexes. The low value of molar conductance indicates them to be non-electrolytes.

Synthesis And Antimicrobial Activity Of N-Alkyl Substituted P-Methyl (E)-3- And 4-Azachalconium Bromides, Nuretti̇n Yayli, Gülbi̇n Misir, Nuran Yayli, Ahmet Yaşar, Emi̇ne Demi̇r, Zi̇hni̇ Demi̇rbağ

Turkish Journal of Chemistry

Twenty new N-alkyl substituted p-methyl (E)-3- and 4-azachalcones (1a-j, 2a-j){3-[(1E)-3-(4-methylp-henyl)-3- oxoprop-1-en-1-yl]-1-alkyl (C_{5-12,_{14-15) pyridinium bromides (1a-j) and 4-[(1E)-3-(4-methylp-henyl)-3-oxoprop-1-en-1-yl]-1-alkyl (C_{5-12,_{14-15) pyridinium bromides (2a-j)} were synthesized and tested for antimicrobial activities against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Enterococcus faecalis, Proteus vulgaris, and Escherichia coli. They showed good antimicrobial activity especially against the gram-positive bacteria tested with minimal inhibitory concentration (MIC) values less than 4.7 \mu g/mL in most cases. The optimum length of the alkyl chain for better and broader activity is situated in the range of 8-12 carbon atoms in the series of compounds 1a-j, 2a-j. The non-alkylated compounds 1-2 were …

Synthesis, Characterization, Crystal Structures, And Antibacterial Activity Of Some New 1-(3,4,5-Trimethoxybenzoyl)-3-Aryl Thioureasreas, Aamer Saeed, Rasheed Ahmad Khera, Naeem Abbas, Muhammad Latif, Imran Sajid, Ulrich Flörke

Turkish Journal of Chemistry

Synthesis of some novel 1-(3,4,5-trimethoxy)benzoyl-3- arylthiourea derivatives (1a-o) was accomplished in 2 steps. The synthetic route involves the reaction of 1-(3,4,5-trimethoxy)benzoyl chloride with potassium thiocyanate in 1:1 molar ratio in acetone to afford the corresponding isothiocyante followed by treatment with suitably substituted anilines. The structures of the products were established by elemental analyses, IR, ^1H- and ^{13}C-NMR, and mass spectroscopy and for 1b and 1m from single crystal X-ray diffraction data. All of the synthesized compounds (1a-o) were screened for antibacterial activity against gram positive and gram negative bacterial strains and were found to exhibit low activity towards the tested …

An Efficient Synthesis Of Schiff Bases Containing Benzimidazole Moiety Catalyzed By Transition Metal Nitrates, Akbar Mobinikhaledi, Naser Foroughifar, Mehdi Kalhor

Turkish Journal of Chemistry

A simple and efficient method has been developed for the synthesis of some novel Schiff bases via the reaction of aromatic aldehydes with 2-aminobenzimidazole by using catalytic amount of M(NO_3)_2.xH_2O in an organic solvent at room temperature. Some advantages of this protocol are its very good yields, use of available catalysts, simple workup procedure, and short reaction times.

Synthesis, Characterization, Antibacterial And Antifungal Evaluation Of Some New Platinum(Ii) Complexes Of 2-Phenylbenzimidazole Ligands, Semra Utku, Mustafa Topal, Ayli̇n Döğen, Mehmet Sami̇ Seri̇n

Turkish Journal of Chemistry

A series of platinum(II) complexes of the type [PtL_2Cl_2] 1, [PtL_2I_2] 2, [PtL_2(oxalato)] 3, and [PtL_2(malonato)] 4 (L= 2-phenylbenzimidazole ligands as ``non-leaving groups'') were synthesized and characterized by their elemental analyses, IR, ^1H NMR, and ESI-LC/MS. The in vitro antimicrobial activity of the synthesized compounds has been evaluated by the macrodilution method against gram-positive bacteria, such as Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis; gram-negative bacteria, such as Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumonia; and yeast like fungi, such as Candida glabrata and Candida parapsilosis. In general, based on the data obtained in this study, synthesized complexes 1-4 might …

Electrochemical Properties Of 1-(O-, M-, P-Nitrophenyl)-3-(M-Nitrophenyl)- 5-Phenylformazans And Their Nickel Complexes, Habi̇be Tezcan, Mehmet Levent Aksu

Turkish Journal of Chemistry

The electrochemical properties of NO_2 formazans and their Ni(II) complexes were investigated. The investigated formazans included a NO_2 group at the o-, m-, and p-positions of the 1-phenyl ring and at the m-position of the 3-phenyl ring. The oxidation and reduction peak potentials, number of electrons transferred, diffusion coefficient, heterogeneous rate constant, and possible reaction mechanism of the compounds were determined with the use of cyclic voltammetry (CV), ultramicrodisc electrodes (UMEs), and chronoamperometry (CA). The peak potentials (E}_{ox1}) were observed to shift towards more anodic potentials in formazans and more cathodic potentials in their respective Ni complexes compared to unsubstituted …