Digital Commons Network^™

En Route Towards Α-Benzotriazoyl Nitroso Derivatives, Jean-Christophe M. Monbaliu, Lucas K. Beagle, Judit K. Beagle, Matthias Zeller, Christian V. Stevens, Alan R. Katritzky

Chemistry Faculty Publications

A new class of geminally-substituted nitroso compounds, i.e., α-benzotriazoyl nitroso derivatives, is presented. These compounds display a rather different behavior than other related nitroso compounds bearing a geminal electron-withdrawing group. An unexpected and spontaneous oxidation to the nitro analog is observed in solution.

Insights On Cytochrome P450 Enzymes And Inhibitors Obtained Through Qsar Studies, Jayalakshmi Sridhar, Jiawang Liu, Maryam Foroozesh, Cheryl Stevens L. Klein Stevens

Faculty and Staff Publications

The cytochrome P450 (CYP) superfamily of heme enzymes play an important role in the metabolism of a large number of endogenous and exogenous compounds, including most of the drugs currently on the market. Inhibitors of CYP enzymes have important roles in the treatment of several disease conditions such as numerous cancers and fungal infections in addition to their critical role in drug-drug interactions. Structure activity relationships (SAR), and three-dimensional quantitative structure activity relationships (3D-QSAR) represent important tools in understanding the interactions of the inhibitors with the active sites of the CYP enzymes. A comprehensive account of the QSAR studies on …

Semiconductor Nanocrystals: From Quantum Dots To Quantum Disks, Zheng Li

Graduate Theses and Dissertations

The bottom-up colloidal synthesis opened up the possibility of finely tuning and tailoring the semiconductor nanocrystals. Numerous recipes were developed for the preparation of colloidal semiconductor nanocrystals, especially the traditional quantum dots. However, due to the lack of thorough understanding to those systems, the synthesis chemistry is still on the empirical level. CdS quantum dots synthesis in non-coordinating solvent were taken as a model system to investigate its molecular mechanism and formation process, ODE was identified as the reducing agent for the preparation of CdS nanocrystals, non-injection and low-temperature synthesis methods developed. In this model system, we not only proved …

Investigating The Biochemical Activity Of Some Flavonoids, Coumarins And Modified Gold-Nanoparticles As Anti-Breast-Cancer Agents, Amr Ezzat Mohamed Mahmoud

Dissertations

Polyphenols compounds are abundant natural products found in many plants as secondary metabolites. These compounds display many interesting pharmacological activities, which have motivated chemists over the years to explore them, and their synthetic derivatives, as potential drugs, especially anticancer drugs. Breast cancer is the most common cancer in women globally, and in the United States of America the estimated worldwide new breast cancer cases and the number of deaths are 1.38 million and 458 thousand, respectively. Currently in the USA there are 2.6 million women who have been treated for breast cancer, and the estimated number of deaths are 39,520 …

Synthesis And Characterization Of Biodegradable Electrospun Polyurethanes For Biomedical Applications, Xujun Zhang

Theses and Dissertations - UTB/UTPA

Two types of polyesters [(Poly(ε-caprolactone) and Poly(δ-valerolactone)] were synthesized by ring-opening polymerization with diethylene glycol as a initiator and stannous octate as a catalyst. The corresponding polyurethanes were synthesized by two-step polymerization with 1,4-diisocyanate butane (BDI) and reacted with 1,4-diamino butane (Putrescine) chain extender. The polymers were characterized by Proton Nuclear Magnetic Resonance (1H NMR), Fourier Transform Infrared Spectroscopy (FT-IR), Raman Spectroscopy, Size-exclusive Chromatography (SEC), Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The resulting polyurethanes were fabricated into nanofibers using an electrospinning technique. The morphological, structural characterizations and thermal properties of the bulk polyurethanes and electrospun polyurethanes nanofibers were …

Synthesis Of Novel Bis-Β-Lactams, Jocabed Marquez

Theses and Dissertations - UTB/UTPA

This study presents the synthesis and structure of newly discovered β-lactams and the mechanism of their synthesis via the Staudinger reaction. β-lactams known as 2-azetidinones, are four membered cyclic amides that have been extensively used and recognized as the central motif of the β-lactam antibiotics, the most widely employed family of antimicrobial agent to date. The Staudinger reaction involves the cycloaddition between an acid chloride with an imine, in presence of a tertiary base. The possibility of cooperative effects from two therapeutic functionalities in drug molecules, has prompted interest in the synthesis of Bis-β-lactams. The synthesis of 2 novel Bis-β-lactams …

Microwave-Induced Bismuth Nitrate-Catalyzed Multicomponent Reaction Toward Heterocycles, Ashwini Bobbala

Theses and Dissertations - UTB/UTPA

The microwave-induced reaction for the synthesis of nitrogen containing heterocyclesis very important in medicinal chemistry. The synthesis of various other valuable compounds is also done by employing this reaction. The aza Diels-Alder reaction is one of the most powerful synthetic tools for the synthesis of nitrogen containing heterocycles. The main goal of the research is to synthesize the nitrogen containing heterocycles using Bismuth nitrate as the catalyst in the presence of microwave irradiation. In the present study we explore the catalytic activity of bismuth nitrate and the role of microwave reactor in the synthesis of 2, 3-diaryl substituted bicyclic octanone …

A Mechanistic Study Of Catalytic Promiscuity In Protein Phosphatase 1, Yuan Chu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

"Catalytic promiscuous" enzymes, which possess additional activities besides their "native" activity, albeit with a lower efficiency than the main reaction, have become a new frontier for biochemistry and have received considerable attention. Catalytic promiscuity has been suggested to contribute to enzyme evolution through the mechanism of gene duplication followed by specialization of one of the two copies for the new function. Mimicking this evolutionary shortcut could also provide a more efficient route to changing the function of proteins by directed evolution.

The promiscuous phosphatase PP1 is a member of the phosphoprotein phosphatase (PPP) gene family, which is critical for the …

Designed Guanidinium-Rich Amphipathic Oligocarbonate Molecular Transporters Complex, Deliver And Release Sirna In Cells, E. I. Geihe, Christina B. Cooley, J. R. Simon, M. K. Kiesewetter, J. A. Edward, R. P. Hickerson, R. L. Kaspar, J. L. Hedrick, R. M. Waymouth, P. A. Wender

Chemistry Faculty Research

The polyanionic nature of oligonucleotides and their enzymatic degradation present challenges for the use of siRNA in research and therapy; among the most notable of these is clinically relevant delivery into cells. To address this problem, we designed and synthesized the first members of a new class of guanidinium-rich amphipathic oligocarbonates that noncovalently complex, deliver, and release siRNA in cells, resulting in robust knockdown of target protein synthesis in vitro as determined using a dual-reporter system. The organocatalytic oligomerization used to synthesize these co-oligomers is step-economical and broadly tunable, affording an exceptionally quick strategy to explore chemical space for optimal …

Environmental Implications And Applications Of Nanomaterials, Priyanka Bhattacharya

All Dissertations

Recent advances in material science and nanotechnology have given rise to a myriad of developments, while in the meantime call for research into the impacts of nanomaterials on the environment and human health. Although considerable progress has been made in the past decade concerning the behavior of nanomaterials in biological systems, such understanding is critically lacking with respect to the fate of nanomaterials in ecosystems.
Accordingly, this dissertation addresses the interactions between nanomaterials and algae--the major constituent of the aquatic food chain (Part I, Chapter two), and exploits the physicochemistry of nanoscaled synthetic dendritic polymers for environmental applications, especially for …

Producing Data To Support The Detection And Understanding Of Early On-Set Corrosion In Accelerated Weathering, Stephanie Suzanne Messer

Master's Theses

The goal of the research reported herein was to generate data towards the development of methods and protocols for detecting, quantifying, and understanding early on-set corrosion events on and above aluminum 2024-T3. The studies focused on incorporating two main fluorescent probes into a few model epoxy and/or urethane coatings to detect X and Y axis specific pH changes occurring upon and above the substrate during pre-macroscopic corrosion. The primary fluorophore used was fluorescein, a pH sensitive probe capable of detecting the changes, mainly increases in pH that accompanies aluminum corrosion. The second molecular probe, rhodamine B, was utilized to better …

Studies Toward The Total Synthesis Of Antascomicin B, David Ross Clay

Graduate Theses and Dissertations

The following dissertation describes synthetic efforts toward the synthesis of the C21-C34 fragment of antascomicin B. Our initial enzymatic approach is detailed as well as an asymmetric transfer hydrogenation (ATH) strategy that will be used in the eventual total synthesis of the molecule. Several investigations into anomalies observed during (ATH) reactions are also discussed.

Part I - A Study Of The Formation Of Carbenes By Elimination Of Α-Bromosilanes And Application Toward The Synthesis Of Transition Metal Complexed Quinone Methide Analogs. Part Ii - Development Of Novel 7-Membered Ring Carbene Ligands For Palladium Catalyzed Cross Coupling Reactions., Christian Michael Loeschel

Graduate Theses and Dissertations

In part I, we wish to report our approaches toward transition metal complexed ortho-quinone methide analogs. ortho-Quinone Methides are a class of highly reactive compounds with a wide range of chemical and biological applications. Previously, a stable iron complexed benzannulated 5-membered ring quinone methide analog was reported by Allison and Neal27. Herein, we report our approaches to improve the reactivity of that system by removing benzannulation as well as changing the metal from iron to manganese and rhenium.

Furthermore, a methodological study on generating carbenes under mild conditions by elimination of α-halosilanes and its application towards metal complexed quinone methide …

Data Mining Of Protein Databases, Christopher Assi

School of Computing: Dissertations, Theses, and Student Research

Data mining of protein databases poses special challenges because many protein databases are non-relational whereas most data mining and machine learning algorithms assume the input data to be a relational database. Protein databases are non-relational mainly because they often contain set data types. We developed new data mining algorithms that can restructure non-relational protein databases so that they become relational and amenable for various data mining and machine learning tools. We applied the new restructuring algorithms to a pancreatic protein database. After the restructuring, we also applied two classification methods, such as decision tree and SVM classifiers and compared their …

Synthesis Of Half-Loaded Nitroimidazole Indocyanine Green Dyes Attached To Carbon Nanotubes, Courtney L. Stanford

Master's Theses

Indocyanine green dye is the only FDA approved NIR fluorescent dye that can be used in humans. 2-Nitroimidazoles are very effective radiosensitizers, have low cytotoxicity, and target hypoxic tissue. By coupling the two together, hypoxic tumors can be targeted and imaged. Previous work has been done to couple 2-nitroimidazole to both sides of the indocyanine green dye. This work focuses on expanding that concept to couple 2-nitroimidazole to only one side of the dye, thus allowing for the other end to be available to couple to another compound, generating a half loaded 2-nitroimidazole indocyanine green dye. In theory, this half-loaded …

Accurate Methodology For Monitoring Biomembrane Events, Christine A. Winschel

Theses and Dissertations

Abstract ACCURATE METHODOLOGY FOR MONITORING BIOMEMBRANE EVENTS By Christine A. Winschel, Ph.D. A Dissertation submitted in partial fulfillment of the requirements for the degree of Doctorate of Philosophy in Chemistry at Virginia Commonwealth University. Virginia Commonwealth University, 2012 Major Director: Dr. Vladimir A. Sidorov ASSOCIATE PROFESSOR, DEPARTMENT OF CHEMISTRY This study describes the synthesis and characterization of a new receptor (cyclen 1) capable of strong selective binding of pyrene-based anionic dyes under near-physiological conditions. This receptor comprises four naphthylthiourea groups tethered to a cyclen core via an ester linkage. The most important finding was the ability of cyclen 1 to …

Discrimination Of Colon Cancer Stem Cells Using Noncanonical Amino Acid, Xinrui Duan, Honglin Li, Hexin Chen, Qian Wang

Faculty Publications

Cancer stem cells (CSCs) may be responsible for tumor recurrence. Metabolic labelling of newly synthesized proteins with non-canonical amino acids allows us to discriminate CSCs in mixed populations due to the quiescent nature of these cells.

Fluorescence Tagging Of Marine Low Molecular Weight Carboxylic Acids, Brian C. Gismervik

Master's Theses

This thesis aims at the evaluation of the best amide bonding strategy that places a fluorescence aminomethyl coumarin tag onto a LMW organic acid in aqueous solution. A three-stage study was conducted. First, a suitable aminomethyl coumarin fluorophore was synthesized. Second, a library of acid-derivatized standards was synthesized for use in optimizing the anticipated HPLC separation of a mixture of LMW acids expected to be found in marine samples. Third, the aforementioned amide coupling strategies were screened to identify the most applicable method for our reaction conditions to the tagging of LMW organic acids in a large number of field …

54th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 54th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Copper Mountain, Colorado, July 15-19, 2012.

Spectroelectrochemical Elucidation Of The Kinetics Of Two Closely Spaced Electron Transfers, Robert L. Keesey, Michael D. Ryan

Chemistry Faculty Research and Publications

The use of spectroelectrochemistry to facilitate the analysis of an EE mechanism was reported in this work. Using a set of spectra as a function of potential, the spectra of all three oxidation states were determined using evolving window factor analysis. From these spectra, the concentration of each species in solution was determined for each potential. Using these data, the current was calculated. Unlike the direct measurement of current, the current due to each redox process was determined, allowing one to analyze each redox process separate from the other. With the use of the Butler–Volmer equation, the redox potential and …

Mitigating Ros Induced Neurodegenerative Pathogenesis Through Polyphenolic Phytochemicals, Brittany N. Talamantes, Parijat Kabiraj, Mahesh Naryan

COURI Symposium Abstracts, Summer 2012

The United States accounts for 16% of all Alzheimer’s disease (AD) cases. The margin of elderly population increasing, due to the baby boomer generation, also contributes greatly to the increase in neurodegenerative diseases. This rise in neurodegenerative disease highlights the importance of research and its potential ability to alleviate financial health burdens as well creating protection for younger generations. Cell lines, PC12 and SHSY-5Y chosen as Parkinsonian and Alzheimer’s models because of their ability to release dopamine were treated with the phytochemical ellagic acid, and analyzed to view its protective capabilities against reactive oxidative stress (ROS). ROS was induced by …

Fluorescence Correlation Spectroscopy Study Of Protein Transport And Dynamic Interactions With Clustered-Charge Peptide Adsorbents, Lydia Kisley

Faculty Scholarship

Ion-exchange chromatography relies on electrostatic interactions between the adsorbent and the adsorbate and is used extensively in protein purification. Conventional ion-exchange chromatography uses ligands that are singly charged and randomly dispersed over the adsorbent, creating a heterogeneous distribution of potential adsorption sites. Clustered-charge ion exchangers exhibit higher affinity, capacity, and selectivity than their dispersed-charge counterparts of the same total charge density. In the present work, we monitored the transport behavior of an anionic protein near clustered-charge adsorbent surfaces using fluorescence correlation spectroscopy. We can resolve protein-free diffusion, hindered diffusion, and association with bare glass, agarose-coated, and agarose-clustered peptide surfaces, demonstrating …

Synthesis Of Methylene Γ-Lactones Using Carbon Dioxide, Bryan P. Ferrell, Shizue Mito, Giber Martinez, Intesar El-Feitouri

COURI Symposium Abstracts, Summer 2012

Many industrial processes generate the greenhouse gas, carbon dioxide, as a byproduct. Carbon dioxide can be captured and recycled by using it in organic synthesis to prepare beneficial compounds. The goal of this project is to develop a new method of synthesizing methylene γ-lactones using CO₂-metal complexes. Many gamma lactones are biologically active, and their synthesis is of importance to pharmaceutical and other industries. Allenes can react with a transition metal-CO₂ complex. It is proposed that a titanium metal complex prepared with an aldehyde will bind to an allene, and a seven-membered ring forms as CO_{2 …}

Evolutionary History And Phylodynamics Of Influenza A And B Neuraminidase (Na) Genes Inferred From Large-Scale Sequence Analyses, Haizhen Zhong

Chemistry Faculty Publications

Background: Influenza neuraminidase (NA) is an important surface glycoprotein and plays a vital role in viral replication and drug development. The NA is found in influenza A and B viruses, with nine subtypes classified in influenza A. The complete knowledge of influenza NA evolutionary history and phylodynamics, although critical for the prevention and control of influenza epidemics and pandemics, remains lacking.

Methodology/Principal findings: Evolutionary and phylogenetic analyses of influenza NA sequences using Maximum Likelihood and Bayesian MCMC methods demonstrated that the divergence of influenza viruses into types A and B occurred earlier than the divergence of influenza A …

Angular And Dynamical Properties In Resonant Inelastic X-Ray Scattering: Case Study Of Chlorine-Containing Molecules, Renaud Guillemin, Wayne C. Stolte, Loic Journel, Stephane Carniato, Maria Novella Piancastelli, Dennis W. Lindle, Marc Simon

Chemistry and Biochemistry Faculty Research

Polarization-dependent resonant inelastic x-ray scattering (RIXS) has been shown to be a probe of molecular-field effects on the electronic structure of isolated molecules. In this experimental analysis we explain the linear dichroism observed in Cl 2p polarized RIXS following Cl 1s excitation of a series of chlorofluoromethanes (CF3Cl, CF2Cl2, CFCl3, and CCl4) as due to molecular-field effects, including singlet-triplet exchange. We present an approach to extract directly the 2p inner-shell electronic state populations from the experimental measurements. Using the angular properties of the measured KV emission we also are able to determine the value of the polarization anisotropy parameter βp …

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 …

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 …

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 …

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 …