Chemistry Commons^™

Redox Potential Tuning By Mixed-Ligand Quadruply Bonded Dimolybdenum Compounds, Nathalie Valdez, Dino Villagran

COURI Symposium Abstracts, Summer 2012

Oxidation-reduction reactions are crucial in chemistry. They are vital for biochemical reactions such as cellular respiration and photosynthesis. Redox reactions are also important in industrial processes, such as the reduction of ores to obtain metals and to produce electrochemical cells. While this field of chemistry has been studied extensively, this project attempts to get a better understanding of electron donor properties of basic ligands attached to bimetallic units. The more basic a ligand is, the better its electron donor properties are which allows us to stabilize higher oxidations states. Guanidine ligands have been found to be able to stabilize higher …

Development Of A New Protecting Group For N-Acetylneuraminic Acid In Glycopeptide Synthesis, Luis A. Barrera, Katja Michael

COURI Symposium Abstracts, Summer 2012

N-acetylneuraminc acid (Neu5Ac) is contained in a tumor-associated antigen called STn, which is expressed in form of glycoproteins on the cell surface of many carcinomas. Synthesized partial sequences (glycopeptides) of these cell surface glycoproteins could potentially be used as anticancer vaccines, or for the production of antibodies which could be useful for immunotherapy. STn-containing glycopeptides are sensitive to acid and base catalyzed decomposition, which makes their chemical synthesis quite challenging. If this research is successful, we may be able to contribute to the advancement of cancer research by making sensitive STn-containing glycopeptides more accessible through chemical synthesis.

My current project …

Synthesis Of Metal Organic Framework Composites For Improved Porosity, Jesse Murillo, Venkata P. Neti, Luis Echegoyen*

COURI Symposium Abstracts, Summer 2012

The synthesis of new highly porous composite materials, by combining Metal Organic Frameworks (MOFs) and graphene derivatives is described. The porosity of these composite materials is confirmed by pore volume, nitrogen uptake, BET and Langmuir surface area calculations. Structural information for the composites is accomplished through powder x-ray diffraction measurements, thermal gravimetric analysis and scanning electron microscopy. MOF-210, reported by Yaghi et al. in 2010, was chosen for composition with a graphene oxide composite due to its record holding pore size and internal surface area. The synthetic route to creation of precursors for MOF-210, as well as MOF-210 synthesis, is …

The Structural Investigation Of An Early Gene Product Of The Avian Adenovirus Celo, Ricardo Parra, Scott Rush, Gustavo A. Avila, Susanna Chiocca, Chuan Xiao

COURI Symposium Abstracts, Summer 2012

After folding into their proper three-dimensional shapes, some proteins will undergo posttranslational modifications in order to fully attain their final function or change among different biologically functional forms. Sumoylation is a posttranslational modification process in which small proteins called SUMO (Small Ubiquitin-like Modifier) will modify the target proteins and alter their functions. The protein under investigation is Gam1, an early gene product of adenovirus CELO (Chicken Embryo Lethal Orphan) which not only inhibits global sumoylation of the host cell facilitating viral propagation, but is also itself sumoylated. This research aims to crystallize and determine the atomic structure of Gam1 in …

Dye-Sensitized Solar Cells, Laiwu Chen, Agustin Molina Ontoria, Luis A. Echegoyen

COURI Symposium Abstracts, Summer 2012

A dye-sensitized solar cell (DSSC) is a low-cost device for converting solar energy and possesses a large-area, flexible, colorful and lightweight devices. It is based on a semiconductor (TiO₂) deposited on a layer of conductive ITO glass. The dye is placed over this semiconductor film, in contact with an electrolyte in order to close the circuit .

The crucial requirements for dye-sensitized solar cells are: (a) wide absorption spectrum; (b) the right anchor to the TiO₂, for instance -COOH; (c) match the energy of the LUMO level of the photosensitizer with the Fermi level of the …

Pcet With Bimetallic Systems, Maripaz A. Calderon, Dino Villagran

COURI Symposium Abstracts, Summer 2012

Electron-transfer (ET) is one of the simplest chemical events, yet it is a vital process for chemical reactivity. Proton-coupled electron transfer (PCET) is the concerted transfer of protons and electrons which is fundamental in chemical and biological systems and processes in electrochemistry, photosynthesis, and enzymatic activity. Similarly, mixed-valence (MV) systems are pervasive in nature and provide a platform for multiple electron transfers systems in nature. While both fields have been studied extensively, little work has been done on the intersection of the two. This project explores the elegant use of MV bimetallic systems through hydrogen-bonded networks. Using standard Schlenk and …

Synthesis Of Palmitoyl Dihydroxyacetonephosphate, Merieme Khamsi, Igor C. Almeida, Katja Michael

COURI Symposium Abstracts, Summer 2012

The parasite Trypanosoma cruzi (T. cruzi) causes Chagas disease which is a big problem in Central and South America, affecting 16-18 million people annually. While there are two non-FDA approved drugs to treat acute Chagas disease, there is no treatment available for its chronic stage. The objective of this project is to synthesize the substrate for acyl dihydroxyacetonephosphate synthase (ADS). This enzyme participates in the first step of alkyl lipid synthesis which is very abundant in T. cruzi, and is a potential target for developing more efficient drugs or inhibitors to treat Chagas disease. Recently, several alkyl phospholipid derivatives …

Study Of Multielectron Redox Chemistry Through Multiple Bonded Bimetallic Species Of The Type M2-L-M, Nancy Rodríguez, Dino Villagrán

COURI Symposium Abstracts, Summer 2012

Multielectron redox chemistry is fundamental for the activation of small molecules, such as H₂O, N₂ and CO₂. Currently, these multielectron redox processes are not well understood and are presently the subject of active research throughout the world due to the evident energy and environmental implications of these small molecules. The goal of this project is the study of multielectron redox chemistry on compounds of the type M₂-L-M. We want to manipulate the reactivity of a M (M=Zn, Co, Ni, Rh, Ir) redox center by a quadruply bonded Mo₂ dimolybdenum core through a …

Solar Synthesis Of Acyl Hydroquinones And Their Bioactivity., Fernando De Leon, Shizue Mito

COURI Symposium Abstracts, Summer 2012

Without the Sun, we would not enjoy the benefits of life here on the Earth. This energy is essential and crucial for sustaining life: playing important roles in circadian rhythms and photosynthesis in plants. In our research, this endlessly renewable clean energy source is utilized for photo-Friedel-Crafts acylation of 1,4 - benzoquinones and 1,4 - naphthoquinones. Photo-Friedel-Crafts acylation was first discovered in 1891 and although there have been reported examples of acylated products, the substrates are still limited. In this project a variety of aldehydes having different substituents are examined, and bioassays were performed. While conventional methods for photochemistry use …

Photo-Switched Interfacial Layers For Organic Solar Cell Applications, Catalina Suárez, Danisha M. Rivera-Nazario, Mahsa Hosseini, Luis Echegoyen

COURI Symposium Abstracts, Summer 2012

Structural and functional diversity have been incorporated in photo-switched donor-acceptor (D-A) systems for the development and improvement of Organic Photovoltaic Cells (OPVs). By varying the structure and electronic properties of the donor and acceptor, the length and electronic properties of the linker, it is possible to control the efficiencies and lifetimes of photo-induced intramolecular charge separated states (D⁺-A^-). Modification of electrodes is a widely studied field for applications in biochemistry, materials science, electrocatalysis, among others. Here we report for the first time the modification of gold (Au) and indium tin oxide (ITO) electrodes with fullerene-based dyads …

Ti2s@C78: A Non-Group-Iii Metal Sulfide Cluster Inside A C78 Cage, Vivian L. Triana, Fang-Fang Li, Luis Echegoyen*

COURI Symposium Abstracts, Summer 2012

After the discovery of the first nitride cluster metallofullerenes (NCFs), Sc₃N@C₈₀, in 1999, numerous cluster metallofullerenes have been prepared. However, the types of “clusterfullerenes” reported so far are quite limited: nitride cluster fullerenes (NCFs), carbide cluster metallofullerenes (CCFs), oxide cluster metallofullerenes (OCFs) and sulfide cluster fullerenes (SCFs). Given that almost all of the encaged metals for all of these reported cluster fullerenes are limited to group-III (Sc, Y, and lanthanide) metals, there are very few reports of the synthesis of cluster fullerenes with a non-group III metal, titanium (Ti), trapped inside a carbon cage. However, the …

Electronic Communication Between Dimolybdenum Units And Ruthenium As A Metal Center Linked By Dimethyloxamide, Daniel D. Anchondo, Dino Villagran

COURI Symposium Abstracts, Summer 2012

Multi-electron redox reactions are important in chemistry. They are crucial in biochemical reactions such as photosynthesis and in many enzymatic processes in nature. Typical examples can be the electrolysis of water which is a four electron process, nitrogen fixation which is a six electron process. Multi-electron redox reactions are also important in industrial processes, such as the reduction of ores to obtain metals and to produce electrochemical cells. Therefore it is vital to study multi-electron redox reactions. We use dimolybdenum units bridged to a ruthenium atom as a platform to study these reactions by measuring the electron communication between two …

Synthesis Of Graphene/Mof-177 Composites, Nathaly Ortiz, Venkata P. Neti, Luis Echegoyen

COURI Symposium Abstracts, Summer 2012

Metal Organic Frameworks (MOFs) are formed by the self-assembly of metallic ions and organic ligands. These compounds have shown excellent properties for gas adsorption and catalytic activity. MOF-177 has one of the highest hydrogen storage capacities reported for porous materials at ambient temperatures (surface area = 3400m²/g), reported previously by Yaghi et al. Graphene and graphene based materials have unique structural, mechanical, and electronic properties. Graphene oxide(GO) and functionalized graphene have been used as support and as a structural pieces in the construction of MOF’s in the past. Synthesis of MOF-5 on the surface of GO and …

Novel Dyad-Fullerene Derivative Used As Acceptor With P3ht In Bulk Heterojunction Solar Cells, Amber D. Berkobien, Luis Echegoyen, Maira Cerón, Danisha Rivera

COURI Symposium Abstracts, Summer 2012

Within the world of solar cells, research is rapidly uncovering potential solutions to the alternative energy issues by utilizing bulk-heterojunction cell techniques (Figure 1a) for low-cost and quick effective manufacturing. In this scope of research, a unique concept of donor-acceptor (D-A) system pairing as an acceptor within the bulk-heterojunction cell has been brought to light; a new concept of utilizing HOMO/LUMO pairings to create effective transport systems between a combination D-A acceptor and polymer donor is being optimized for maximum Photo-Conversion Efficiency (PCE). Due to a similar band gap relationship between the commonly reported PCBM and the novel dyad fullerene …

Design, Synthesis And Evaluation Of Novel Diazirine Photolabels With Improved Ambient Light Stability And Fluorous-Based Enrichment Capacity, Arun Babu Kumar

USF Tampa Graduate Theses and Dissertations

Photoaffinity labeling is a quintessential technique in studying and analyzing the interaction between a ligand and receptor. Diazirines are one of the important photo-labile moieties used in photoaffinity labeling due to their superior photo labeling characteristics. Herein, we report the investigations we conducted with diazirine photolabels on (a) photochemical aspects leading to enhancement of their ambient light stability and (b) equipping them with fluorous tags to enable fluorous enrichment of labeled proteins. Furthermore, we report a pilot study to develop BACE-1 inhibitors, which have potential to be developed into photoaffinity probes.

3-Trifluoromethyl-3-phenyldiazirine offers good selectivity and protection against pseudolabeling but …

Integrated Approach For Low-Cost And Sensitive Multiplex Pathogen Detection On 3d Paper-Based Microfluidic Devices, Alejandra Valadez, Huan Hu, Xiujun James Li

COURI Symposium Abstracts, Summer 2012

Recently, pathogenic microorganisms have aroused wide public concern for their potential to cause serious diseases in humans, animals and agricultural crops. Although DNA microarrays are commonly used for pathogen detection, the approach is sophisticated, time-consuming and requires expensive equipment, limiting its application in resource-poor settings. Herein we present a novel, low-cost, paper-based microfluidic approach for multiplexed DNA detection of Giardia Lamblia, S. aureus, and Entamoeba, by “on-chip” isothermal DNA amplification and hybridization. Paper-based microfluidics offers a novel, sensitive and low-cost alternative for Point-of-Care Diagnostics for the Developing Countries. The project described utilizes Loop-mediated Isothermal Amplification (LAMP), a novel isothermal DNA …

Development Of Novel Organocatalytic Cascade Reactions And Application In Organic Systheses, Xixi Song

Chemistry and Chemical Biology ETDs

The development of new catalytic reactions, particularly synthetically efficient cascade processes for the facile preparation of important molecular architectures, which otherwise are difficult to access via traditional methods, is of considerable significance. Toward this end, my Ph.D. work focuses on developing new organocatalytic reactions and their applications in organic syntheses. A novel direct organocatalytic stereoselective α-arylation methodology has been discovered. The cross-coupling-like products are assembled using simple enals and various brominated aromatic systems, such as p-bromophenols, bromonaphthols and 3-bromoindoles. The products have been applied in the concise photo-syntheses of [α]-annulated carbazoles. Moreover, an unexpected reaction has been identified with aliphatic …

Il-6 Regulation On Skeletal Muscle Mitochondrial Remodeling During Cancer Cachexia In The ApcMin/+ Mouse, James P. White, Melissa J. Puppa, Shuichi Sato, Song Gao, Robert L. Price, John W. Baynes, Matthew C. Kostek, Lydia E. Matesic, James A. Carson

Faculty Publications

BACKGROUND:

Muscle protein turnover regulation during cancer cachexia is being rapidly defined, and skeletal muscle mitochondria function appears coupled to processes regulating muscle wasting. Skeletal muscle oxidative capacity and the expression of proteins regulating mitochondrial biogenesis and dynamics are disrupted in severely cachectic Apc^Min/+ mice. It has not been determined if these changes occur at the onset of cachexia and are necessary for the progression of muscle wasting. Exercise and anti-cytokine therapies have proven effective in preventing cachexia development in tumor bearing mice, while their effect on mitochondrial content, biogenesis and dynamics is not well understood. The purposes of …

Inhibition Of Pokeweed Antiviral Protein (Pap) By Turnip Mosaic Virus Genome-Linked Protein (Vpg), Artem V. Domashevskiy, Hiroshi Miyoshi, Dixie J. Goss

Publications and Research

Pokeweed antiviral protein (PAP) from Phytolacca americana is a ribosome-inactivating protein (RIP) and an RNA N-glycosidase that removes specific purine residues from the sarcin/ricin loop of large rRNA, arresting protein synthesis at the translocation step. PAP is also a cap-binding protein and is a potent antiviral agent against many plant, animal, and human viruses. To elucidate the mechanism of RNA depurination, and to understand how PAP recognizes and targets various RNAs, the interactions between PAP and turnip mosaic virus genomelinked protein (VPg) were investigated. VPg can function as a cap analog in cap-independent translation and potentially target PAP to uncapped …

N-Acyl Ciprofloxacins: Synthesis, Antibacterial Activity And Effects On Molecular Loading Of Poly(Vinyl Benzoate) Nanoparticles, Ryan Cormier

USF Tampa Graduate Theses and Dissertations

Bacterial infections are becoming progressively more difficult to treat due to antibiotic resistance and the decreasing rate at which new antibiotics are brought to market. The Turos laboratory has attempted to tackle this problem for the last 15 years with the discovery of N-thiolated β-lactams leading to the design of polyacrylate nanoparticles to deliver these and other drugs. Chapter 1 discusses many reported instances of utilizing different types of polymeric nanoparticles to deliver antibiotics. Poly(lactic-co-glycolic acid) (PLGA), poly(alkyl cyanoacrylate) (PACA), poly(styrene-co-butylacrylate), and chitosan are the main polymers used to make nanoparticles. Chapter 2 describes the synthesis, antibacterial activity, and mechanism …

A Proposed Palladium-Catalyzed Cycle For The Epoxidation Of Alkenes, Marie Vernell Parkes

Chemistry and Chemical Biology ETDs

Epoxides are an important chemical functional group, used in a wide variety of processes, from the small-scale production of pharmaceuticals to the large-scale production of propylene oxide. Current methods for production of epoxides require costly multi-step syntheses that use toxic or explosive reagents, result in low yields, and produce co-products that must be removed and often disposed. The development of an atom-efficient general method, preferably catalytic, for converting alkenes to epoxides using safe, cheap, and readily available molecular oxygen as the stoichiometric oxidant would be a great advance in both industrial and academic chemistry. Presented here is a proposed catalytic …

The Synthesis And Structural Characterization Of Metal Oxide Nanoparticles Having Catalytic Applications, Stacey Janel Smith

Theses and Dissertations

Nanotechnology is blossoming into one of the premiere technologies of this century, but the key to its progress lies in developing more efficient nanosynthesis methods. Variations in synthetic technique, however, can cause variations in size, structure, and surface characteristics, thereby altering the physical properties and functionality of the particles. Careful structural characterizations are thus essential for understanding the properties and appropriate applications for particles produced by new synthetic techniques.In this work, a new ‘solvent-deficient’ method is presented for the synthesis of an unprecedentedly wide range of metal oxide nanomaterials including at least one metal oxide from each group in Groups …

Production Of Bioactive Secondary Metabolites By Florida Harmful Bloom Dinoflagellates Karenia Brevis And Pyrodinium Bahamense, Cheska Burleson

USF Tampa Graduate Theses and Dissertations

Despite the critical role algae serve as primary producers, increases or accumulation of certain algae may result in Harmful Algal Blooms (HABs). Algal toxins from these blooms contribute significantly to incidences of food borne illness, and evidence suggests HABs are expanding in frequency and distribution. Mitigation of these HABs without knowledge of the ecological purpose and biochemical regulation of their toxins is highly unlikely. The production, function, and potential of secondary metabolites produced by the dinoflagellates Karenia brevis and Pyrodinium bahamense, were investigated.

Brevetoxins were demonstrated by two different methods to localize within the cytosol of Karenia brevis. …

Interaction Of Human Telomeric Dna With N-Methyl Mesoporphyrin Ix, John Michael Nicoludis , '12, Steven Paul Barrett , '13, J.-L. Mergny, Liliya A. Yatsunyk

Chemistry & Biochemistry Faculty Works

The remarkable selectivity of N-methyl mesoporphyrin IX (NMM) for G-quadruplexes (GQs) is long known, however its ability to stabilize and bind GQs has not been investigated in detail. Through the use of circular dichroism, UV-visible spectroscopy and fluorescence resonance energy transfer (FRET) melting assay we have shown that NMM stabilizes human telomeric DNA dAG(3)(TTAG(3))(3) (Tel22) and is selective for its parallel conformation to which it binds in 1:1 stoichiometry with a binding constant of similar to 1.0 x 10(5) M-1. NMM does not interact with an antiparallel conformation of Tel22 in sodium buffer and is the second example in the …

Transparent Conducting Films Of Cdse(Zns) Core(Shell) Quantum Dot Xerogels, Lasantha Korala, Li Li, Stephanie L. Brock

Chemistry Faculty Research Publications

A method of fabricating sol–gel quantum dot (QD) films is demonstrated, and their optical, structural and electrical properties are evaluated. The CdSe(ZnS) xerogel films remain quantum confined, yet are highly conductive (10⁻³ S cm⁻¹). This approach provides a pathway for the exploitation of QD gels in optoelectronic applications.

Halogen Activation Via Interactions With Environmental Ice And Snow In The Polar Lower Troposphere And Other Regions, J. P. D. Abbatt, J. L. Thomas, K. Abrahamsson, Chris Boxe, A. Granfors, A. E. Jones, M. D. King, A. Saiz-Lopez, P. B. Shepson, J. Sodeau, D. W. Toohey, C. Toubin, R. Von Glasow, S. N. Wren, X. Yang

Publications and Research

The role of ice in the formation of chemically active halogens in the environment requires a full understanding because of its role in atmospheric chemistry, including controlling the regional atmospheric oxidizing capacity in specific situations. In particular, ice and snow are important for facilitating multiphase oxidative chemistry and as media upon which marine algae live. This paper reviews the nature of environmental ice substrates that participate in halogen chemistry, describes the reactions that occur on such substrates, presents the field evidence for ice-mediated halogen activation, summarizes our best understanding of ice-halogen activation mechanisms, and describes the current state of modeling …

Organic Synthesis Based On Name Reaction: A Practical Guide To Over 700 Transformations (Book Review), Jeffrey H. Glans

Chemistry & Physics Faculty Publications

Book review by Jeffrey Glans:

Hassner, Alfred and I. Namboothiri. Organic Synthesis Based on Name Reaction: A Practical Guide to Over 700 Transformations. 3rd ed. Amsterdam; Boston: Elsevier, 2012.

ISBN 9780080966304

Recovery Of Sensitive Watersheds In The Northeastern United States From Chronic Acidification: The Role Of Soil Chemistry, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.

Mercury Transportation In Soil Using Gypsum From Flue Gas Desulphurization Unit In Coal-Fired Power Plant, Kelin Wang

Masters Theses & Specialist Projects

This work investigates mercury flux in soil amended by gypsum from flue gas desulphurization (FGD) units of coal-fired power plants. There are two phases of this research, including field and greenhouse studies. Previous studies indicate that FGD gypsum could increase corn yield, but may lead to more mercury uptake by corn.

Recent studies have been carried out in greenhouses to investigate mercury transport in FGD gypsum treated soil. Major aspects include uptake of mercury by plants and emission of mercury into the atmosphere based on application rates of FGD gypsum. Additional aspects include rainfall, temperature, soil, and plants types. Higher …

Understanding How The Platinum Anticancer Drug Carboplatin Works: From The Bottle To The Cell, Anthony J. Di Pasqua, Jerry Goodisman, James C. Dabrowiak

Chemistry - All Scholarship

Carboplatin, a platinum anticancer drug used to treat many types of human cancer, contains a bidentate dicarboxylate chelate leaving ligand, a structural feature that makes it much less chemically reactive than the first-generation platinum anticancer drug cisplatin, which contains two monodentate chloride leaving ligands. In water, carboplatin exists in a monomer-dimer equilibrium with an association constant of K (M ^-1) ≈ 391, a property that accounts for the long-term stability of its ready-to-use infusion solution. When administered in the clinic, carboplatin is believed to exert its biological effects by interacting with genomic DNA and proteins. The slower substitution kinetics …