Chemistry Commons^™

Effect Of A Strategically Positioned Methoxy Substituent On The Photochemistry Of 3-Aryl-3h-1-Oxacyclopenta[L]Phenanthren-2-Ones, Roshini Thumpakara, Binoy Jose, Perupparampil Unnikrishnan, Sreedharan Prathapan, Nigam Rath

Chemistry & Biochemistry Faculty Works

Irradiation of 3-methoxy-3-aryl-3H-1-oxacyclopenta[l]phenanthren-2-one derivatives 5a–d resulted in singlet-mediated decarbonylation reaction leading to the formation of phenanthrene derivatives 9a–d. The structure of the photoproduct was unequivocally established on the basis of X-ray crystallographic analysis.

The Vinylguaiacol/Indole Or Vgi ("Veggie") Ratio: A Novel Molecular Parameter To Evaluate The Relative Contributions Of Terrestrial And Aquatic Organic Matter To Sediments., Michael A. Kruge, Kevin K. Olsen, Jaroslaw W. Slusarczyk, Elaine Gomez

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The organic matter (OM) fraction of estuarine sediments is often distinctive and thus diagnostically useful in determinations of sedimentary provenance. Among the most fundamental distinctions to be made is that between terrestrial and aquatic OM. To supplement the parameters commonly used for this purpose (e.g., C/N and stable isotope ratios), we proposed the Vinylguaiacol/Indole or VGI ("Veggie") ratio, defined as [vinylguaiacol / (indole + vinylguaiacol)] using data produced by analytical pyrolysis-gas chromatography/mass spectrometry of dried, homogenized sediment samples. The ratio employs the peak areas of these two compounds on the mass chromatograms of their molecular ions (m/z 150 and 117). …

Biomarkers Of Mild Cognitive Impairment And Alzheimer's Disease, Mark A. Lovell, Bert C. Lynn

Chemistry Faculty Patents

A method for quantifying a neurodegenerative disorder in a patient that includes obtaining a fluid sample from the subject; measuring a protein biomarker complex in said fluid sample and correlating the measurement with mild cognitive impairment or Alzheimer's disease status. The biomarkers include those that comprise at least one of a transthyretin protein and/or a prostaglandin-H2 D-isomerase protein, and at least one second, different protein selected from a transthyretin, prostaglandin-H2 D-isomerase, beta-2-microglobulin, cystatin C, superoxide dismutase [Cu—Zn], plasma retinol-binding protein, phosphatidylethanolamine-binding protein, carbonic anhydrase 2, prostaglandin-H2 D-isomerase, and/or serotransferrin protein.

Precatalysts Useful In Polyolefin Polymerization Reactions, Omofolami Tesileem Ladipo, Richard Eaves, Alexey Zazybin, Sean Parkin

Chemistry Faculty Patents

Compounds are provided that are useful as precatlysts in the polymerization of olefins such as ethylene and propylene. Other compounds are useful as intermediates in the production of such precatalysts.

Superhydrophobic Thin Films Fabricated By Reactive Layer-By-Layer Assembly Of Azlactone-Functionalized Polymers, Maren E. Buck, Sarina C. Schwartz, David M. Lynn

Chemistry: Faculty Publications

We report an approach to the fabrication of superhydrophobic thin films that is based on the "reactive" layer-by-layer assembly of azlactone-containing polymer multilayers. We demonstrate that films fabricated from alternating layers of the azlactone functionalized polymer poly(2-vinyl- 4,4-dimethylazlactone) (PVDMA) and poly(ethyleneimine) (PEI) exhibit micro- and nanoscale surface features that result in water contact angles in excess of 150°. Our results reveal that the formation of these surface features is (i) dependent upon film thickness (i.e., the number of layers of PEI and PVDMA deposited) and (ii) that it is influenced strongly by the presence (or absence) of cyclic azlactone-functionalized oligomers …

Isomer-Dependent Adsorption And Release Of Cis- And Trans-Platin Anticancer Drugs By Mesopomus Silica Nanoparticles, Zhimin Tao, Youwei Xie, Jerry Goodisman, Tewodros Asefa

Chemistry - All Scholarship

We report on adsorption and release of the anticancer drugs cisplatin and transplatin from mesoporous silica nanomaterials, emphasizing the differences between cisplatin and its much less toxic isomer. Two types of particles, M.CM-41 and SBA-IS, were used, either as just synthesized or after calcination to remove the templates. The particles were characterized by TEM, nitrogen physisorption, and elemental analysis. The UV-vis spectra of cisplatin and transplatin were obtained and the intensities of several bands (205-210 nm, 210-220 nm, 220-235 nm, and 300-330 nm) were found proportional to drug concentrations, allowing their use for measuring drug concentration. To evaluate drug adsorption …

10th Annual Senior Research Symposium Of The Department Of Biological Sciences, Chemistry And Biochemistry, Messiah College

School of Science, Engineering & Health (SEH) Symposium

No abstract provided.

Ua1b1/2 L.Y. Lancaster Lecture Series, Wku Archives

WKU Archives Collection Inventories

Records regarding the L.Y. Lancaster Lecture Series.

Hybrid Micro-/Nanogels For Optical Sensing And Intracellular Imaging, Weitai Wu, Shuiqin Zhou

Publications and Research

Hybrid micro-/nanogels are playing an increasing important part in a diverse range of applications, due to their tunable dimensions, large surface area, stable interior network structure, and a very short response time. We review recent advances and challenges in the developments of hybrid micro-/nanogels toward applications for optical sensing of pH, temperature, glucose, ions, and other species as well as for intracellular imaging. Due to their unique advantages, hybrid micro-/nanogels as optical probes are attracting substantial interests for continuous monitoring of chemical parameters in complex samples such as blood and bioreactor fluids, in chemical research and industry, and in food …

Direct Patterning Of Silanized-Biomolecules On Semiconductor Surfaces, Dorjderem Nyamjav, Richard C. Holz

Chemistry Faculty Research and Publications

A novel approach to pattern silanized-biomolecules directly onto glass (SiO_x) substrates via Dip-Pen nanolithography (DPN) and microcontact printing (μCP) is presented. Subsequent hybridization reactions of DPN patterned silanized-DNA with its complementary strands provide “proof-of-concept” that the patterned oligonucleotides maintain their biological activities. The fabrication strategy does not require premodification of substrates and offers a cheap and robust way to immobilize molecules on electronically important semiconductor surfaces.

Dual Inhibition Of Sodium-Mediated Proton And Calcium Efflux Triggers Non-Apoptotic Cell Death In Malignant Gliomas, William Harley, Candace Floyd, Tamara Dunn, Xiao-Dong Zhang, Tsung-Yu Chen, Manu Hegde, Hasan Palandoken, Michael H. Nantz, Leonardo Leon, K.L. Carraway Iii, Bruce Lyeth, Fredric A. Gorin

Chemistry and Biochemistry

Malignant glioma cells maintain an elevated intracellular pH (pH_i) within hypoxic–ischemic tumormicroenvironments through persistent activation of sodium–proton transport (McLean et al., 2000). Amiloride has been reported to selectively kill human malignant glioma cell lines but not primary astrocytes (Hegde et al., 2004). While amiloride reduces pH_i of malignant gliomas by inhibiting isoform 1 of sodium–proton exchange (NHE1), direct acidification was shown to be cytostatic rather than cytotoxic. At cytotoxic concentrations, amiloride has multiple drug targets including inhibition of NHE1 and sodium–calciumexchange. Amiloride's glioma cytotoxicity can be explained, at least in part, by dual inhibition of NHE1 and …

Nicholas Reactions In The Construction Of Cyclohepta[De]Naphthalenes And Cyclohepta[De]Naphthalenones. The Total Synthesis Of Microstegiol, Rafiq Taj, James R. Green

Chemistry and Biochemistry Publications

The application of the Nicholas reaction chemistry of 2,7-dioxygenated naphthalenes in the synthesis of cyclohepta[de]napthalenes and in the synthesis of (±)-microstegiol (1) is presented. The substitution profile of Nicholas monosubstitution (predominantly C-1) and disubstitution reactions (predominantly 1,6-) on 2,7-dioxygenated napthalenes is reported. Application of a 1,8-dicondensation product and selected C-1 monocondensation products to the construction of cyclohepta[de]naphthalenes by way of ring closing metathesis and intramolecular Friedel−Crafts reactions, respectively, is described. Deprotection of the C-7 oxygen function to the corresponding naphthol allows tautomerization to cyclohepta[de]naphthalene-1-ones upon seven-membered-ring closure in most cases, and replacement …

Intramolecular Nicholas Reactions In The Synthesis Of Dibenzocycloheptanes. Synthesis Of Allocolchicine Nsc 51046 And Analogues And The Formal Synthesis Of (−)-Allocolchicine, Sinisa Djurdjevic, Fei Yang, James R. Green

Chemistry and Biochemistry Publications

The preparation of dibenzocycloheptyne-Co₂(CO)₆ complexes by intramolecular Nicholas reactions of biaryl-2-propargyl alcohol-Co₂(CO)₆ derivatives is described. Reductive decomplexation of the dibenzocycloheptyne-Co₂(CO)₆ complexes affords the corresponding dibenzocycloheptenes, individual members of which have been employed in a formal total synthesis of (−)-allocolchicine, the preparation of 6,7-dihydro-3,4,9,10,11-pentamethoxy-5H-dibenzo[a,c]cyclohepten-5-one, and the enantioselective total syntheses of NSC 51046 and its 3,8,9,10-tetramethoxy regioisomer.

Measurements Of Gas‐Phase Inorganic And Organic Acids From Biomass Fires By Negative‐Ion Proton‐Transfer Chemical‐Ionization Mass Spectrometry, P. Veres, James M. Roberts, I. R. Burling, C. Warneke, Joost De Gouw, Robert J. Yokelson

Chemistry and Biochemistry Faculty Publications

[1] Emissions from 34 laboratory biomass fires were investigated at the combustion facility of the U.S. Department of Agriculture Fire Sciences Laboratory in Missoula, Montana. Gas-phase organic and inorganic acids were quantified using negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), open-path Fourier transform infrared spectroscopy (OP-FTIR), and proton-transfer-reaction mass spectrometry (PTR-MS). NI-PT-CIMS is a novel technique that measures the mass-to-charge ratio (m/z) of ions generated from reactions of acetate (CH₃C(O)O⁻) ions with inorganic and organic acids. The emission ratios for various important reactive acids with respect to CO were determined. Emission ratios for isocyanic acid (HNCO), 1,2 …

A Concise Synthesis Of Β-Sitosterol And Other Phytosterols, Jiliang Hang, Patrick Dussault

Patrick Dussault Publications

A convenient synthesis of sidechain-modified phytosterols is achieved via a temporary masking of the stigmasterol 5,6-alkene as an epoxide. Following performance of the desired modification, the alkene is regenerated through a mild deoxygenation. The approach is applied to the syntheses of β-sitosterol and campesterol acetate, and suggests a facile route to the (Z)-isomers of Δ^22–23 phytosterols.

Includes Supplementary Data.

Quantum Chemical Studies Of Nucleic Acids Can We Construct A Bridge To The Rna Structural Biology And Bioinformatics Communities?, Jiri Sponer,, Judit Sponer, Anton I. Petrov, Neocles B. Leontis

Chemistry Faculty Publications

In this feature article we provide a side-by-side introduction for two research fields quantum chemical calculations of molecular interaction in nucleic acids and RNA structural bioinformatics Our main aim is to demonstrate that these research areas while largely separated in contemporary literature have substantial potential to complement each other that could significantly contribute to our understanding of the exciting world of nucleic acids We identify research questions amenable to the combined application of modern ab initio methods and bioinformatics analysis of experimental structures while also assessing the limitations of these approaches The ultimate aim is to attain valuable physicochemical insights …

Electrochemical Investigation Of Azurin Thermodynamic And Adsorption Properties At Monolayer-Protected Cluster Film Assemblies – Evidence For A More Homogeneous Adsorption Interface, Tran Doan, Morgan Lynn Vargo, John K. Gerig, Chris P. Gulka, Matthew L. Trawick, Jonathan D. Dattelbaum, Michael C. Leopold

Chemistry Faculty Publications

Thermodynamic and adsorption properties of protein monolayer electrochemistry (PME) are examined for Pseudomonas aeruginosa azurin (AZ) immobilized at an electrode modified with a networked film of monolayer-protected clusters (MPCs) to assess if nanoparticle films of this nature offer a more homogeneous adsorption interface compared to traditional self-assembled monolayer (SAM) modified electrodes. Specifically, electrochemistry is used to assess properties of surface coverage, formal potential, peak broadening, and electron transfer (ET) kinetics as a function of film thickness. The modification of a surface with dithiol-linked films of MPCs (Au225C675) provides a more uniform binding interface for AZ that results in voltammetry with …

Study On Intumescent Flame Retarded Polystyrene Composites With Improved Flame Retardancy, Hongdian Lu, Charles A. Wilkie

Chemistry Faculty Research and Publications

The flame retardancy and thermal stability of ammonium polyphosphate/tripentaerythritol (APP/TPE) intumescent flame retarded polystyrene composites (PS/IFR) combined with organically-modified layered inorganic materials (montmorillonite clay and zirconium phosphate), nanofiber (multiwall carbon nanotubs), nanoparticle (Fe₂O₃) and nickel catalyst were evaluated by cone calorimetry, microscale combustion calorimetry (MCC) and thermogravimetric analysis (TGA). Cone calorimetry revealed that a small substitution of IFR by most of these fillers (≤2%) imparted substantial improvement in flammability performance. The montmorillonite clay exhibited the highest efficiency in reducing the peak heat release rate of PS/IFR composite, while zirconium phosphate modified with C₂₁H_{26 …}

Two-Phase Partitioning System Using Elvax 40w Polymer For The Biodegradation Of Aqueous Phenols, Amit Suresh Ghode

Masters Theses & Specialist Projects

A solid-liquid two phase partitioning system (TPPS) is a new technology platform for destroying toxic organic compounds. TPPS have traditionally been operated by using an immiscible organic phase which partitions organic compounds into the aqueous phase. TPPS using an immiscible organic phase suffers from several limitations such as the organic phase could be biodegradable and hence only certain compatible microbial strains could be used. This therefore, eliminates the desired use of mixed microbial populations for efficient degradation. A solid-liquid two phase partitioning system, in which solid polymeric beads replace liquid organic phase, appears to have benefits over the traditional liquid-liquid …

Investigation Of Volatile Products From Wood Pyrolysis, Prabhavathi Gade

Masters Theses & Specialist Projects

In this research we are following the thermo-chemical degradation of wood in the absence of oxygen. The objectives are to evaluate the influence of heating rates on pyrolysis products obtained from wood pyrolysis and to evaluate the influence of acid pre-treatment on pyrolysis products. Depending on the wood heating rates, pyrolysis can be categorized as Flash pyrolysis, Fast pyrolysis, and Slow pyrolysis. We have evaluated the volatile products obtained at different heating rates and the volatile products obtained from sulfuric acid pre-treatment by using gas chromatography- mass spectrometry (GC-MS). We have also performed thermo-gravimetric analysis (TGA) of raw wood samples …

Development And Validation Of A Rapid Multi-Class Method For The Confirmation Of Fourteen Prohibited Medicinal Additives In Pig And Poultry Compound Feed By Liquid Chromatography Tandem Mass Spectrometry, Mark Cronly, Patrice Behan, Barry Foley, Liam Regan, Marella Gallagher, Sean Earley, Paula Shearan, Edward Malone

Articles

A confirmatory method has been developed to allow for the analysis of fourteen prohibited medicinal additives in pig and poultry compound feed. These compounds are prohibited for use as feed additives although some are still authorised for use in medicated feed. Feed samples are extracted by acetonitrile with addition of sodium sulphate. The extracts undergo a hexane wash to aid with sample purification. The extracts are then evaporated to dryness and reconstituted in initial mobile phase. The samples undergo an ultracentrifugation step prior to injection onto the LC-MS/MS system and are analysed in a run time of 26 minutes. The …

Characteristics And Stability Of Oxide Films On Plutonium Surfaces, Harry Guillermo García Flores

Department of Chemistry: Dissertations, Theses, and Student Research

The oxidation of plutonium (Pu) metal continues to be an area of considerable activity. The reaction characteristics have significant implications for production use, storage, and disposition of this radiological material. Developing an accurate physical model of the structures, oxidation states, and oxygen concentration gradients present during oxidation are essential to understanding this process. Traditionally, the stable oxides of Pu have been thought to be plutonium sesquioxide (Pu₂O₃, O/Pu = 1.5, Pu³⁺) and plutonium dioxide (PuO₂, O/Pu = 2.0, Pu⁴⁺), existing in a layered structure on Pu metal. Many of the …

Iota-Carrageenan Hydrolysis By Pseudoalteromonas Carrageenovora Ifo12985, Bernadette M. Henares, Erwin P. Enriquez, Fabian M. Dayrit, Nina Rosario L. Rojas

Chemistry Faculty Publications

We report iota-carrageenan hydrolysis by Pseudoalteromonas carrageenovora IFO 12985. Kappa-carrageenase and lambda-carrageenase were previously isolated from this organism, but iota-carrageenase activity had not been reported in the literature. P. carrageenovora was grown in iota-carrageenan-based liquid medium. Using the zone of depression assay, transfer of aliquots of the culture to solid medium with 2% iota- and kappa-carrageenan showed extensive hydrolysis of iota-carrageenan. Analysis of the hydrolysates by C-13 Nuclear Magnetic Resonance spectroscopy confirmed degradation of the iota-carrageenan. Hydrolytic activity of P. carrageenovora grown in iota-carrageenan was compared with that of the same organism grown in kappa-carrageenan. Cell-free supernatants from each yielded …

Ultrasonic Activation Of Triacetone Triperoxide, Latravia R. Dobson

Department of Chemistry: Dissertations, Theses, and Student Research

Triacetone triperoxide (TATP) is an organic peroxide that has received widespread attention in recent years. TATP is a ketone peroxide with a high active oxygen content. It is relatively shock sensitive, with explosive decomposition easily initiated, and is therefore considered a primary explosive. However, TATP is also a powerful explosive possessing about 83 % of the power of TNT. TATP can be prepared quickly and easily from inexpensive household chemicals in the absence of any specialized facilities, making it the explosive of choice for modern day terrorists.

TATP poses a major challenge for security and law enforcement services around the …

Synthesis And Catalytic Activity Of Nanostructured Cerium Oxide, Neil J. Lawrence

Department of Chemistry: Dissertations, Theses, and Student Research

Cerium oxide (ceria, CeO_2-x where x is 0 to 0.5) has been one of the most widely used heterogeneous catalysts particularly in three way catalytic converters. Most of the catalytic traits can be attributed to two properties of ceria: first, the high mobility and storage capacity of oxygen within the lattice; second, the ease with which cerium changes between Ce³⁺ and Ce⁴⁺ states. These properties, combined with the abundance of cerium on earth, make ceria a low-cost highly effective alternative to noble metal catalysts. Recent research has been focused on the nanoscale properties of ceria.

The effect …

I. A New Synthetic Approach To The Synthesis Of N-(Phosphonoacetyl)-L-Ornithine, Ii. The Influence Of Pyridine On The Ozonolysis Of Alkenes, Bradley M. Johnson

Department of Chemistry: Dissertations, Theses, and Student Research

Part I. The use of chemical inhibitors to manipulate the level of amino acids in cells has proven to be invaluable in the mechanistic study of gene expression in bacteria and fungi. Here we present a new approach to the synthesis of δ‐N‐ (phosphonoacetyl)‐L‐ornithine (PALO), a potent ornithine transcarbamylase inhibitor, using a new amino acid protecting group, 9‐borabicyclononane (9‐BBN). Starting from commercially available reagents and utilizing mild reaction conditions, we were able to form PALO in fewer synthetic steps and in greater yields than previous attempts.

Part II. Ozonolysis is widely used to transform alkenes into oxygen‐rich functional groups (e.g.– …

On-Metal Synthesis Of Some Rhenium Complexes, Chad L. Phillips

Mahurin Honors College Capstone Experience/Thesis Projects

In 1977, Shirakawa and coworkers discovered the first conductive polymers. Their conductive polymers have been extensively studied. Though some of these first conductive polymers such as polyactelyne seemed to be a promising organic conductor, the commercial applications of these polymers were severely limited due the polymer’s highly air-sensitive nature. Thus, the current focus has shifted towards the development of heterocyclic aromatic polymers which are air-stable and have a low band gap. Expanding of the work of Snyder and Selegue, the focus of my research has been the incorporation of rhenium metal into an organic compound in an on-metal fashion. Several …

Nuclear Magnetic Resonance Affinity Screening Methods For Functional Annotation Of Proteins And Drug Discovery, Matthew D. Shortridge Phd

Department of Chemistry: Dissertations, Theses, and Student Research

With nearly 1,350 complete genome sequences available our understanding of biology at the molecular level has never been more complete. A consequence of these sequencing projects was the discovery of large functionally unannotated segments of each genome. The genes (and proteins they encode) found in these unannotated regions are considered “hypothetical proteins”. Current estimates suggest between 12%-50% of the known gene sequences are functionally unannotated. Incomplete functional annotation of the various genomes significantly limits our understanding of biology. Pragmatically, identifying the functions of these proteins could lead to new therapeutics; making functional annotation of paramount importance.

This dissertation describes the …

Systematic Approach To Electrostatically Induced 2d Crystallization Of Nanoparticles At Liquid Interfaces, Sumit Kewalramani, Suntao Wang, Yuan Lin, Huong Giang Nguyen, Qian Wang, Masafumi Fukuto, Lin Yang

Faculty Publications

We report an experimental demonstration of a strategy for inducing two-dimensional (2D)crystallization of charged nanoparticles on oppositely charged fluid interfaces. This strategy aims to maximize the interfacial adsorption of nanoparticles, and hence their lateral packing density, by utilizing a combination of weakly charged particles and a high surface charge density on the planar interface. In order to test this approach, we investigated the assembly of cowpea mosaic virus (CPMV) on positively charged lipid monolayers at the aqueous solution surface, by means of in situX-ray scattering measurements at the liquid–vapor interface. Theassembly was studied as a function of the solution …

[Fe-Fe]-Hydrogenase Reactivated By Residue Mutations As Bridging Carbonyl Rearranges: A Qm/Mm Study, Stefan Motiu, Valentin Gogonea

Chemistry Faculty Publications

In this work, we found aqueous enzyme phase reaction pathways for the reactivation of the exogenously inhibited [Fe-Fe]-hydrogenases by O2, or OH−, which metabolizes to H2O (Dogaru et al., Int J Quantum Chem 2008, 108; Motiu et al., Int J Quantum Chem 2007, 107, 1248). We used the hybrid quantum mechanics/molecular mechanics (QM/MM) method to study the reactivation pathways of the exogenously inhibited enzyme matrix. The ONIOM calculations performed on the enzyme agree with experimental results (Liu et al., J Am Chem Soc 2002, 124, 5175), that is, wild-type [Fe-Fe]-hydrogenase H-cluster is inhibited by oxygen metabolites. An enzyme spherical region …