Digital Commons Network^™

15. Pharmacy, University Of Central Oklahoma

Oklahoma Research Day Abstracts

No abstract provided.

17. Psychology, University Of Central Oklahoma

Oklahoma Research Day Abstracts

No abstract provided.

19. Zoology, University Of Central Oklahoma

Oklahoma Research Day Abstracts

No abstract provided.

Synthesis And Biological Activity Of Indolinones, Kaleb Woodrow Cox

Browse all Theses and Dissertations

Indolinones of the type known as Arylidene oxindoles have been demonstrated to possess a broad range of activity ranging from proten kinase inhibtors, cell-death inhibitors and tau protein binding agents. Small libraries of such molecules were designed and synthesized herein in modifications involving variously substituted halogen derivatives, N-alkylation of the indolinone nitrogen, and finally a new class of molecules, namely arylidene oxindoles possessing extended conjugation. The biological activities of such molecules were examined and the results disclosed herein.

03. Biology, University Of Central Oklahoma

Oklahoma Research Day Abstracts

No abstract provided.

13. Mathematics, University Of Central Oklahoma

Oklahoma Research Day Abstracts

No abstract provided.

16. Physics, University Of Central Oklahoma

Oklahoma Research Day Abstracts

No abstract provided.

Astroecology, Cosmo-Ecology, And The Future Of Life, Michael Noah Mautner

Chemistry Publications

Astroecology concerns the relations between life and space resources, and cosmo-ecology extrapolates these relations to cosmological scales. Experimental astroecology can quantify the amounts of life that can be derived from space resources. For this purpose, soluble carbon and electrolyte nutrients were measured in asteroid/meteorite materials. Microorganisms and plant cultures were observed to grow on these materials, whose fertilities are similar to productive agricultural soils. Based on measured nutrient contents, the 10²² kg carbonaceous asteroids can yield 10¹⁸ kg biomass with N and P as limiting nutrients (compared with the estimated 10¹⁵ kg biomass on Earth). These data …

Amides Are Excellent Mimics Of Phosphate Internucleoside Linkages And Are Well Tolerated In Short Interfering Rnas, Daniel Mutisya, Chelliah Selvam, Benjamin Lunstad, Pradeep S. Pallan, Amanda Haas, Devin Leake, Martin Egli, Eriks Rozners

Chemistry Faculty Scholarship

RNA interference (RNAi) has become an important tool in functional genomics and has an intriguing therapeutic potential. However, the current design of short interfering RNAs (siRNAs) is not optimal for in vivo applications. Non-ionic phosphate backbone modifications may have the potential to improve the properties of siRNAs, but are little explored in RNAi technologies. Using X-ray crystallography and RNAi activity assays, the present study demonstrates that 3'-CH2-CO-NH-5' amides are excellent replacements for phosphodiester internucleoside linkages in RNA. The crystal structure shows that amide-modified RNA forms a typical A-form duplex. The amide carbonyl group points into the major groove and assumes …

A Novel Two-Laser Interface For Coupling Capillary Electrochromatography With Ion-Trap Time-Of-Flight Mass Spectrometry, David C. Simpson, Alexander J. Yates, John H. Knox, Pat R.R. Langridge-Smith

Chemistry Publications

An interface has been developed for the hyphenation of capillary electrochromatography (CEC) with mass spectrometry (MS). Chromatographic eluate vaporization and selective analyte ionization occur within a quadrupole ion-trap, which permits significant instrument simplification when compared with the atmospheric pressure interfaces typically used for CEC-MS. Vaporization is achieved using laser desorption at 1064 nm while ionization is accomplished through UV photoionization. This two-step approach, through ionization laser wavelength selection, can provide ultratrace analysis with high selectivity. The mass spectrometer is a hybrid ion-trap time-of-flight (TOF) instrument in which the ion-trap is used in radio frequency-only mode, with DC-pulse ejection, to provide …

Effects Of Charge And Substituent On The S∙∙∙N Chalcogen Bond, U. Adhikari, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Neutral complexes containing a S···N chalcogen bond are compared with similar systems in which a positive charge has been added to the S-containing electron acceptor, using high-level ab initio calculations. The effects on both XS···N and XS+···N bonds are evaluated for a range of different substituents X = CH3, CF3, NH2, NO2, OH, Cl, and F, using NH3 as the common electron donor. The binding energy of XMeS···NH3 varies between 2.3 and 4.3 kcal/mol, with the strongest interaction occurring for X = F. The binding is strengthened by a factor of 2–10 in charged XH2S+···NH3 complexes, reaching a maximum of …

02. Animal Science, University Of Central Oklahoma

Oklahoma Research Day Abstracts

No abstract provided.

07. Criminal Justice, University Of Central Oklahoma

Oklahoma Research Day Abstracts

No abstract provided.

11. Genetics, University Of Central Oklahoma

Oklahoma Research Day Abstracts

No abstract provided.

18. Statistics, University Of Central Oklahoma

Oklahoma Research Day Abstracts

No abstract provided.

Applications Of Epr With An Emphasis On Tau Fibril Structure, Virginia Meyer

Electronic Theses and Dissertations

Substances containing unpaired electrons have been studied by electron paramagnetic resonance (EPR) for nearly 70 years. With continual development and enhancement of EPR techniques, questions have arisen regarding optimum method selection for a given sample based on its properties. In this work, radiation defects, natural lattice defects, solid organic radicals, radicals in solution, and spin-labeled proteins were analyzed using CW, pulse, and rapid scan EPR to compare methods. Studies of solid BDPA, E' in quartz, N_s⁰ in diamond, and a-Si:H, showed that rapid scan could overcome many obstacles presented by other techniques, cementing rapid scan as an effective …

Probing Structure For Photophysical Properties Through Synthesis Of Novel Nucleosides, Brittney Jean Rodgers

Electronic Theses and Dissertations

A brief history of nucleosides and their photophysics provides the background information for the discussion of synthesis, photophysics and incorporation of fluorescent nucleotide analogs during enzymatic DNA synthesis. Through the use of nucleoside starting material, it is possible to synthesize a number of modified nucleotides for use as fluorescent probes in biochemical research. Synthetic endeavors into the synthesis of these and related molecules from nucleobase starting materials are also presented. The synthesis of these molecules involved re-development of the synthetic routes to broaden substrate scope by overcoming the changed reactivity resulting from the presence of additional functionality.

While many highly …

In Actu Et In Silicio: Linear And Nonlinear Photophysical Characterization Of A Novel Europium Complex, And Incorporating Computational Calculations In The Analysis Of Novel Organic Compounds, Adam Woodward

Electronic Theses and Dissertations

Despite not being a tangible substance, light is becoming an increasingly valuable tool in numerous areas of science and technology: the use of laser excitation of a fluorescent probe can generate incredibly detailed images of cellular structures without the need for large amounts of dissection; new types of solar cells are being produced using organic dyes to harvest light; computer data can be stored by inducing a chemical change in a compound through irradiation with light. However, before any of these materials can be applied in such a way, their properties must first be analyzed for them to be deemed …

Investigation Into The Cellular Actions Of Carnosine And C-Peptide, Emma H. Gardner

Theses, Dissertations and Capstones

Carnosine is a dipeptide composed of beta-alanine and histidine found exclusively in long-lived animal tissues. The cellular action of carnosine is still under extensive investigation; however, it has been proposed to have a role as an anti-oxidant and oxygen free radical scavenger, a physiological buffer, a heavy metal chelator, and has been implicated as an anti-aging agent.^2,4 Our lab has been studying the interaction between carnosine and heme by analyzing both the effect carnosine has on the glycation of the heme containing protein cytochrome c and the interaction of carnosine with free hemin. We have observed that the addition …

Competition Between Lone Pair-Π, Halogen Bond, And Hydrogen Bond In Adducts Of Water With Perhalogenated Alkenes C2clnf4-N (N = 0-4), U. Adhikari, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

A thorough search of the potential energy surface is carried out for heterodimers of water with C2ClnF4−n. Three different types of interactions are observed. Structures dominated by a lone pair–π interaction have the highest binding energies, and are stabilized by charge transfer from O lone pairs of H2O to the Csingle bondC π* antibonding orbital of the alkene. Halogen-bonded O⋯Cl complexes are slightly less strongly bound, followed by OH⋯X hydrogen bonds. The replacements of Cl by F atoms have only small effects upon binding energies. Inclusion of vibrational and entropic effects removes the clear energetic superiority of lp–π binding energies. …

A Td-Dft Study Of The Absorption Spectra Of Mono-Nitrated Fluoranthenes [Abstract], Kefa Karimu Onchoke

Faculty Publications

No abstract provided.

Synthesis Of Fluorescent Molecules And Their Applications As Viscosity Sensors, Metal Ion Indicators, And Near-Infrared Probes, Mengyuan Wang

Electronic Theses and Dissertations

The primary focus of this dissertation is the development of novel fluorescent near-infrared molecules for various applications. In Chapter 1, a compound dU-BZ synthesized via Sonogashira coupling reaction methodology is described. A deoxyuridine building block was introduced to enhance hydrophilic properties and reduce toxicity, while an alkynylated benzothiazolium dye was incorporated for near-IR emission and reduce photodamage and phototoxicity that is characteristic of common fluorphores that are excited by UV or visible light. A 30-fold enhancement of fluorescence intensity of dU-BZ was achieved in a viscous environment. Values of fluorescence quantum yields in 99% glycerol/1% methanol (v/v) of varying temperature …

Analysis Of A Chemical Model System Leading To Chiral Symmetry Breaking: Implications For The Evolution Of Homochirality, Brandy N. Morneau, Jaclyn M. Kubala, Carl Barratt, Pauline Schwartz

Chemistry and Chemical Engineering Faculty Publications

Explaining the evolution of a predominantly homochiral environment on the early Earth remains an outstanding challenge in chemistry. We explore here the mathematical features of a simple chemical model system that simulates chiral symmetry breaking and amplification towards homochirality. The model simulates the reaction of a prochiral molecule to yield enantiomers via interaction with an achiral surface. Kinetically, the reactions and rate constants are chosen so as to treat the two enantiomeric forms symmetrically. The system, however, incorporates a mechanism whereby a random event might trigger chiral symmetry breaking and the formation of a dominant enantiomer; the non-linear dynamics of …

Complexation Of N So2 Molecules (N=1,2,3) With Formaldehyde And Thioformaldehyde, L. M. Azofra, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Ab initio and density functional theory calculations are used to examine complexes formed between H2CO and H2CS with 1, 2, and 3 molecules of SO2. The nature of the interactions is probed by a variety of means, including electrostatic potentials, natural bond orbital, atoms in molecules, energy decomposition, and electron density redistribution maps. The dimers are relatively strongly bound, with interaction energies exceeding 5 kcal/mol. The structures are cyclic, containing both a O/S⋯S chalcogen bond and a CH⋯O H-bond. Addition of a second SO2 molecule leads to a variety of heterotrimer structures, most of which resemble the original dimer, where …

Complexes Containing Co2 And So2. Mixed Dimers, Trimers And Tetramers, L. M. Azofra, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Mixed dimers, trimers and tetramers composed of SO2 and CO2 molecules are examined by ab initio calculations to identify all minimum energy structures. While AIM formalism leads to the idea of a pair of C···O bonds in the most stable heterodimer, bound by some 2 kcal mol(-1), NBO analysis describes the bonding in terms of charge transfer from O lone pairs of SO2 to the CO π* antibonding orbitals. The second minimum on the surface, just slightly less stable, is described by AIM as containing a single O···O chalcogen bond. The NBO picture is that of two transfers in opposite …

Interaction Between Temozolomide And Water: Preferred Binding Sites, O. E. Kasende, A. Matondo, M. Muzomwe, J. T. Muya, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Computational methods are used to predict the most favorable site of temozolomide towards attack by a water molecule. The energetics of the various complexes are presented as well as their geometries, including perturbations of each subunit caused by the presence of the other. Molecular electrostatic potential and Natural Bond Orbital (NBO) data are used to understand the interactions which conclude the terminal amide group is the preferred attack site where water can act as simultaneous proton donor and acceptor. Other potential proton acceptor N atoms within the aromatic ring structure represent weaker binding sites. Some of the less strongly bound …

Substituent Effects In The Noncovalent Bonding Of So2 To Molecules Containing A Carbonyl Group. The Dominating Role Of The Chalcogen Bond, L. M. Azofra, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The SO2 molecule is paired with a number of carbonyl-containing molecules, and the properties of the resulting complexes are calculated by high-level ab initio theory. The global minimum of each pair is held together primarily by a S···O chalcogen bond wherein the lone pairs of the carbonyl O transfer charge to the π* antibonding SO orbital, supplemented by smaller contributions from weak CH···O H-bonds. The binding energies vary between 4.2 and 8.6 kcal/mol, competitive with even some of the stronger noncovalent forces such as H-bonds and halogen bonds. The geometrical arrangement places the carbonyl O atom above the plane of …

An Exploration Of The Ozone Dimer Potential Energy Surface, L. M. Azofra, I. Alkorta, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The (O3)2 dimer potential energy surface is thoroughly explored at the ab initio CCSD(T) computational level. Five minima are characterized with binding energies between 0.35 and 2.24 kcal/mol. The most stable may be characterized as slipped parallel, with the two O3 monomers situated in parallel planes. Partitioning of the interaction energy points to dispersion and exchange as the prime contributors to the stability, with varying contributions from electrostatic energy, which is repulsive in one case. Atoms in Molecules analysis of the wavefunction presents specific O⋯O bonding interactions, whose number is related to the overall stability of each dimer. All internal …

Intrinsic Delocalization During The Decay Of Excitons In Polymeric Solar Cells, Thomas George, W. Chen, D. Jiang, R. Chen, S. Li

Chemistry & Biochemistry Faculty Works

In bulk heterojunction polymer solar cells, external photoexcitation results in localized excitons in the polymer chain. After hot exciton formation and subsequent relaxation, the dipole moment drives the electron to partially transfer to extended orbitals from the original localized ones, leading to self-delocalization. Based on the dynamic fluorescence spectra, the delocalization of excitons is revealed to be an intrinsic property dominated by exciton decay, acting as a bridge for the exciton to diffuse in the polymeric solar cell. The modification of the dipole moment enhances the efficiency of polymer solar cells.

Constructing Tailored Isoprenoid Products By Structure-Guided Modification Of Geranylgeranyl Reductase, Yan Kung, Ryan P. Mcandrew, Xinkai Xie, Charlie C. Liu, Jose H. Pereira, Paul D. Adams, Jay D. Keasling

Chemistry Faculty Research and Scholarship

The archaeal enzyme geranylgeranyl reductase (GGR) catalyzes hydrogenation of carbon-carbon double bonds to produce the saturated alkyl chains of the organism's unusual isoprenoid-derived cell membrane. Enzymatic reduction of isoprenoid double bonds is of considerable interest both to natural products researchers and to synthetic biologists interested in the microbial production of isoprenoid drug or biofuel molecules. Here we present crystal structures of GGR from Sulfolobus acidocaldarius, including the structure of GGR bound to geranylgeranyl pyrophosphate (GGPP). The structures are presented alongside activity data that depict the sequential reduction of GGPP to H(6)GGPP via the intermediates H(2)GGPP and H(4)GGPP. We then modified …