Extraction And Purification Of Biologically Active Metabolites From Rhodococcus Sp. Mtm3w5.2, 2018 East Tennessee State University
Extraction And Purification Of Biologically Active Metabolites From Rhodococcus Sp. Mtm3w5.2, Mohrah Alenazi
Electronic Theses and Dissertations
Rhodococcushas been recognized as a potential antibiotic producer. Recently, a strain of Rhodococcussp. MTM3W5.2 was isolated from a soil sample collected in Morristown, Tennessee and was found to produce an inhibitory compound which is active against other related species. The purpose of this research is to extract, purify and analyze the active metabolite. The compound was extracted from RM broth cultures and purified by preliminary fractionation of crude extract through a Sephadex LH-20 column. Further purification was completed using semi-preparative reversed phase column chromatography. Final purification was obtained using multiple rounds of an analytical C18 HPLC column ...
Synthesis Of Dicamba Glucosides For The Study Of Environmental Dicamba Drift Effects On Soybeans, 2018 University of Arkansas, Fayetteville
Synthesis Of Dicamba Glucosides For The Study Of Environmental Dicamba Drift Effects On Soybeans, Holly Wallace
Theses and Dissertations
The most popular herbicide used for weed control has been glyphosate for many years in the Midwestern United States. Plants have begun to develop a resistance to glyphosate due to over use of the herbicide. This herbicide resistance has pushed farmers to turn to alternative herbicides such as dicamba and 2,4-D. Recently agrochemical companies have developed genetically modified crops that are resistant to herbicides such as dicamba. These modified crops allow farmers to spray their fields with dicamba without fear of crop damage. Farmers of non-genetically modified crops, however, suffer damage and loss of yield from herbicide drift effects ...
Development Of Copper-Catalyzed Suzuki-Miyaura Coupling Using Alkylboron Reagents And Nickel-Catalyzed Alkene Dicarbofunctionalization Reactions, Prakash Basnet
This thesis is divided into two parts. The first part deals with the development of copper-catalyzed Suzuki-Miyaura coupling of alkylboron reagents for the first time. In the second part, we will discuss the development of novel nickel-catalyzed alkene dicarbofunctionalization reactions.
Part I. Cross-coupling reactions are versatile tools to form new carbon-carbon bonds and are widely used in the synthesis of various drug molecules, natural products and materials. However, these reactions are typically catalyzed by palladium, an expensive and rare metal which makes the reaction unsustainable in long-terms. Additionally, palladium-catalyzed cross-coupling reactions with alkylorganometallic reagents suffer from side reactions due to ...
Spatial Mapping And Profiling Of Metabolite Distributions During Germination, 2018 Iowa State University and Ames Laboratory
Spatial Mapping And Profiling Of Metabolite Distributions During Germination, Adam D. Feenstra, Liza E. Alexander, Zhihong Song, Andrew R. Korte, Marna D. Yandeau-Nelson, Basil J. Nikolau, Young-Jin Lee
Germination is a highly complex process by which seeds begin to develop and establish themselves as viable organisms. In this paper, we utilize a combination of GC-MS, LC-fluorescence, and mass spectrometry imaging (MSI) approaches to profile and visualize the metabolic distributions of germinating seeds from two different inbreds of maize seeds, B73 and Mo17. GC and LC analyses demonstrate that the two inbreds are highly differentiated in their metabolite profiles throughout the course of germination, especially with regard to amino acids, sugar alcohols, and small organic acids. Crude dissection of the seed followed by GC-MS analysis of polar metabolites also ...
Modulating Patterns Of Two-Phase Flow With Electric Fields, 2018 University of Washington - Seattle Campus
Modulating Patterns Of Two-Phase Flow With Electric Fields, Dingsheng Liu, Bejan Hakimi, Michael Volny, Joelle Rolfs, Robbyn Anand, Rantisek Turecek, Daniel T. Chiu
This paper describes the use of electro-hydrodynamic actuation to control the transition between three major flow patterns of an aqueous-oil Newtonian flowin a microchannel: droplets, beads-on-a-string (BOAS), and multi-stream laminar flow. We observed interesting transitional flow patterns between droplets and BOAS as the electric field was modulated. The ability to control flow patterns of a two-phase fluid in a microchannel adds to the microfluidic tool box and improves our understanding of this interesting fluid behavior.
An In Vitro Study On Skin Protection Across The Uv Spectra, 2018 Murray State University
An In Vitro Study On Skin Protection Across The Uv Spectra, Cheyenne Boone
Skin cancer is the number one cancer in the United States. Lack of awareness of how harmful UV radiation is could be the cause of the over two million cases reported since 2012. It appears that there is not a lot information on the active ingredients used in sunscreens. Some of the compounds have been linked to birth defects, hormone disruptions, and the bleaching of coral reefs. Samples of commonly used sunscreens (both sprays and creams), cosmetic foundation, essential oils, lotions, and three pure organic actives were tested at specific concentrations and ran through a UV spectrometer. The results have ...
Selective Glucose Isomerization To Fructose Via Nitrogen-Doped Solid Base Catalyst Derived From Spent Coffee Grounds, Season S. Chen, Iris K.M. Yu, Dong-Wan Cho, Hocheol Song, Daniel C.W. Tsang, Jean-Philippe Tessonnier, Yong Sik Ok, Chi Sun Poon
Chemical and Biological Engineering Publications
In this work, glucose isomerization to fructose was conducted via a solid base biochar catalyst derived from spent coffee grounds and melamine. The X-ray photoelectron spectroscopy (XPS) spectra identified the majority of pyridinic nitrogen on the biochar surface, which imparted the strong base character of the catalyst. Activity of the catalyst was evidenced by fast conversion of glucose (12%) and high selectivity to fructose (84%) in 20 min at a moderate temperature (120 °C) compared to recently reported immobilized tertiary amines at comparable N concentrations (10-15 mol% relative to glucose). By increasing the reaction temperature to 160 °C, fructose yield ...
Reaction Optimization Of Pyrazinoquinoxaline Based Organic Semiconductor With Cruciform Shape, 2018 University of Nevada, Las Vegas
Reaction Optimization Of Pyrazinoquinoxaline Based Organic Semiconductor With Cruciform Shape, Marco Valverde Paredes, Dong-Chan Lee
LSAMP Poster Presentations
In this work, an optimum reaction condition was established to synthesize a pyrazinoquinoxaline based organic semiconductor with cruciform shape.
Flexible Laser-Induced Graphene For Nitrogen Sensing In Soil, 2018 Iowa State University
Flexible Laser-Induced Graphene For Nitrogen Sensing In Soil, Nate T. Garland, Eric S. Mclamore, Nicholas D. Cavallaro, Deyny Mendivelso-Perez, Emily A. Smith, Dapeng Jing, Jonathan C. Claussen
Mechanical Engineering Publications
Flexible graphene electronics are rapidly gaining interest, but their widespread implementation has been impeded by challenges with ink preparation, ink printing, and post-print annealing processes. Laser-induced graphene (LIG) promises a facile alternative by creating flexible graphene electronics on polyimide substrates through a one-step laser writing fabrication method. Herein we demonstrate the use of LIG, created through a low-cost UV laser, for electrochemical ion selective sensing of plant-available nitrogen (i.e., both ammonium and nitrate ions: NH4+ and NO3-) in soil samples. The laser used to create the LIG was operated at distinct pulse rates (10, 20, 30, 40, and 50 ...
An Overview Of Dynamic Heterogeneous Oxidations In The Troposphere, 2018 University of Kentucky
An Overview Of Dynamic Heterogeneous Oxidations In The Troposphere, Elizabeth A. Pillar-Little, Marcelo I. Guzman
Chemistry Faculty Publications
Due to the adverse effect of atmospheric aerosols on public health and their ability to affect climate, extensive research has been undertaken in recent decades to understand their sources and sinks, as well as to study their physical and chemical properties. Atmospheric aerosols are important players in the Earth’s radiative budget, affecting incoming and outgoing solar radiation through absorption and scattering by direct and indirect means. While the cooling properties of pure inorganic aerosols are relatively well understood, the impact of organic aerosols on the radiative budget is unclear. Additionally, organic aerosols are transformed through chemical reactions during atmospheric ...
Illuminating Biology With Membrane Penetrating Sulfonate Delivery Scaffolds And Near-Infrared Azasiline Fluorophores, 2018 University of Massachusetts Medical School
Illuminating Biology With Membrane Penetrating Sulfonate Delivery Scaffolds And Near-Infrared Azasiline Fluorophores, Adam Choi
GSBS Dissertations and Theses
Near-infrared (NIR) light, with wavelengths of 650 to 900 nanometers, effectively penetrates tissues. The high signal to noise ratio and low phototoxicity of NIR light makes this wavelength range ideal for deep tissue imaging. However, current NIR fluorophores are generally large hydrophobic molecules that are prone to aggregation. Sulfonation can enhance aqueous solubility, but their anionic nature prevents membrane diffusion, and thus, restricts the applications of sulfonated molecules to in vitro or fixed cells.
The repertoire of commercially available sulfonated NIR probes is mostly limited cyanines, which have low photostability. Moreover, larger cyanines require multiple sulfonates to maintain aqueous solubility ...
Archean Phosphorus Liberation Induced By Iron Redox Geochemistry, 2018 University of South Florida
Archean Phosphorus Liberation Induced By Iron Redox Geochemistry, Barry Herschy, Sae Jung Chang, Ruth Blake, Aivo Lepland, Heather Abbott-Lyon, Jacqueline Sampson, Zachary Atlas, Terence P. Kee, Matthew A. Pasek
The element phosphorus (P) is central to ecosystem growth and is proposed to be a limiting nutrient for life. The Archean ocean may have been strongly phosphorus-limited due to the selective binding of phosphate to iron oxyhydroxide. Here we report a new route to solubilizing phosphorus in the ancient oceans: reduction of phosphate to phosphite by iron(II) at low (<200 >°C) diagenetic temperatures. Reduction of phosphate to phosphite was likely widespread in the Archean, as the reaction occurs rapidly and is demonstrated from thermochemical modeling, experimental analogs, and detection of phosphite in early Archean rocks. We further demonstrate that the ...200>
Synthesis And Evaluation Of Densely-Functionalized Troponoids, 2018 The Graduate Center, City University of New York
Synthesis And Evaluation Of Densely-Functionalized Troponoids, Danielle R. Hirsch
All Dissertations, Theses, and Capstone Projects
Herein, we document our efforts to expand the scope of troponoid synthetic methodology towards densely-substituted scaffolds. This body of work has focused primarily on an oxidopyrylium cycloaddition/ring-opening strategy for the synthesis and biochemical evaluation of troponoids for assistance in a variety of medicinal chemistry studies. In Chapter 1, we outline the use of this synthetic strategy in the profiling of a library of synthetic αHTs against an aminoglycoside antibiotic resistance enzyme known as aminoglycoside-2’’-O-nucleotidyltransferase [ANT(2’’)-Ia]. Enzymatic mechanistic insights have been gleaned from an assessment of troponoid/antibiotic synergistic potential. In particular, two synthetic constructs were identified ...
A Stereospecific Pd-Catalyzed Suzuki Cross-Coupling Reaction And A Statistical Study Of The Ligand's Role In Stereoselection, 2018 The Graduate Center, City University of New York
A Stereospecific Pd-Catalyzed Suzuki Cross-Coupling Reaction And A Statistical Study Of The Ligand's Role In Stereoselection, Shibin Zhao
All Dissertations, Theses, and Capstone Projects
The development of palladium-catalyzed carbon-carbon cross-coupling reactions has profoundly influenced the manner through which we approach the synthesis of complex organic molecules. Among established cross-coupling reactions, which include Kumada, Negishi, and Stille reactions, the Suzuki cross-coupling reaction exhibits particularly wide functional group compatibility, while employing non-toxic, air-stable organoboron nucleophiles. Conventional studies of Pd-catalyzed Suzuki cross-coupling reactions have focused on C(sp2)-C(sp2) cross-coupling reactions, which result in the formation of planar products. Conceptually, the use of C(sp3) (secondary) nucleophiles would enable the reliable manipulation of organic molecules in three dimensions. However, this process has not ...
The Development Of Metal Complexes As Components Of Fluorescent And Nuclear Imaging Probes, 2018 The University of Western Ontario
The Development Of Metal Complexes As Components Of Fluorescent And Nuclear Imaging Probes, William Turnbull
Electronic Thesis and Dissertation Repository
The advent of molecular imaging as a discipline has drastically improved our ability to understand the biochemical and cellular events that drive life, death and disease. This thesis will document the discovery of new metal chelators for Re/99mTc, new methods of incorporating these metals into peptide structures, as well as new fluorescent compounds. These novel methods and compounds may be used in the development of molecular imaging probes for single photon emission computed tomography (SPECT) and optical imaging techniques, with applications for differentiating cancerous tissue from benign and healthy.
Chapter 2 discusses the development of a dual modality ...
Thienoisatin Oligomers As N-Type Molecular Semiconductors, 2018 Purdue University
Thienoisatin Oligomers As N-Type Molecular Semiconductors, Natalie M. Kadlubowski, Xuyi Luo, Jianguo Mei
The Summer Undergraduate Research Fellowship (SURF) Symposium
Organic field effect transistors (OFETs) offer many advantages compared to traditional inorganic transistors, such as flexibility and solution processability. In this study we design and synthesize two thienoisatin-based organic semiconducting small molecules, then investigate their electronic properties in n-type OFETs. To introduce n-type charge transport, electron-withdrawing dicarbonitrile moieties were installed on thienoisoindigo and bis-thienoisatin molecules, which led to a quinoidal conjugation on thienoisoindigo, while maintaining an aromatic conjugation on the bis-thienoisatin. Following the syntheses, the molecules were characterized to determine highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels via cyclic voltammetry, as well as any potential ...
Examining The Effects Of Amino And Thiolate Ligands On The Reactivity And Selectivity Of Palladium On Carbon In Hydrogenation Reactions, Eric Liu, Christina Li
The Summer Undergraduate Research Fellowship (SURF) Symposium
Heterogeneous catalysts are used widely by chemical and energy industries because they show high reactivity but often suffer from lack of selectivity. On the other hand, ligands are commonly used in homogeneous catalysts to control the reactivity and selectivity; however, the effects of the ligands on the steric and electronic properties of heterogeneous catalysts are less understood. We examine the effects of four different ligands: 1-adamantanethiol, 1-adamantylamine, 1-dodecanethiol, and 1-dodecylamine, for the commercial hydrogenation catalyst palladium on carbon. Hydrogenation reactions are used as a screening tool to see the behavior that the different catalysts exhibit in the presence of unsaturated ...
Studies In Molecular Recognition: Non-Proteogenic Amino Acids For Antibiotic Studies And Chemosensors For Recognition And Reporting Of Metal-Ions, 2018 University of Wisconsin-Milwaukee
Studies In Molecular Recognition: Non-Proteogenic Amino Acids For Antibiotic Studies And Chemosensors For Recognition And Reporting Of Metal-Ions, Sarah Anne Oehm
Theses and Dissertations
The field of molecular recognition focuses on the selective and reversible binding of small guest molecules to larger host molecules. This dissertation describes synthesis of small molecules as binding guests for enzymatic substrates as well as molecules as host chemosensors to detect and identify metal ions. Two approaches to new antibiotic drugs have been explored, and an array of sensors for the quantitation of aqueous metals is being commercialized.
As strains of deadly bacteria emerge with evolved resistance to known antibiotics, new drugs are needed with novel mechanisms of action. Natural product antibiotics containing enduracididine, a non-canonical amino acid derived ...
Nmr Spectroscopic Properties Of Nucleotides, And A New Method Of Numeric Calculation Of Raman Intensities For Organic Molecules, 2018 Missouri State University
Nmr Spectroscopic Properties Of Nucleotides, And A New Method Of Numeric Calculation Of Raman Intensities For Organic Molecules, William R. Ehrhardt
MSU Graduate Theses
General and accurate computational methodologies are currently lacking for large chemical systems. This is primarily due to the computational expense required to perform calculations on systems with one hundred or more atoms. Calculated spectroscopic properties could aid in the process of elucidating structural features of large biologically relevant molecules if accurate and inexpensive methods are developed. Towards this end the first steps were taken to design a general methodology for predicting NMR chemical shifts of large nucleic acid systems. It was found that HF and semi-empirical methods were not sufficient for optimization of nucleobases, and therefore larger nucleotide or nucleic ...
Synthesis, Characterization, And Applications Of Ammonium/Phosphonium Chitosan Derivatives For Investigative Dna Interactions, 2018 Missouri State University
Synthesis, Characterization, And Applications Of Ammonium/Phosphonium Chitosan Derivatives For Investigative Dna Interactions, Quinton Kirk Wyatt
MSU Graduate Theses
Chitosan is examined as a non-viral vector capable of efficient gene delivery due to its favorable properties such as biodegradability, biocompatibility, and is non-toxic to mammalian cells. Cell modifications and vector permeability are enhanced in non-viral vectors that incorporate electrostatic interactions. This work synthesizes cationic (N+, P+) chitosan derivatives, to enhance electrostatic interactions towards nucleotides, using amide coupling agents EDC and HOBt. The final chitosan derivatives will bear cationic functional groups (N+, P+) with various alkyl groups (Me, Et, Pr, Ph) to examine their affinities to nucleotides and antifungal properties. mPEG grafted cationic chitosan derivatives were also synthesized to examine ...