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2020
Friday, April 24th

Poster Number: 112

Synthesis of Diarylpyridines as Aggregation Inhibitors for Alzheimer’s Amyloid-β Peptide

Kendall J. Claxton, Winthrop University

Faculty Mentor: James M. Hanna Jr., Ph.D., and Robin K. Lammi, Ph.D.

Amyloid-β peptide (Aβ) self-assembles into neurotoxic, β-structured aggregates, which are the primary component of the extracellular senile plaques characteristic of Alzheimer’s disease. A variety of small molecules have been shown to inhibit the aggregation process; typically, these contain aromatic groups and one or more hydrogen-bond donors. Previous studies have demonstrated that terphenyltetrols exhibit some degree of efficacy as Aβ aggregation inhibitors. For example, o-terphenyl-3,3″,4,4″-tetrol is a moderately effective inhibitor of Aβ aggregation (IC50 = 2.7±0.3X). Recent modeling studies suggest that binding of small molecules to Aβ may occur via several types of intermolecular interactions, including both hydrogen bonding and π-π interactions (i.e., π-stacking). In addition, other studies indicate that π-interactions between benzene and electron-deficient heterocyclic aromatic rings are stronger than similar benzene-benzene interactions. Based on these observations, it is hypothesized that incorporation of a pyridine unit as the central linker in the above-described tetrahydroxyteraryl scaffold may lead to increased inhibition of Aβ aggregation. Therefore, the present study set out to synthesize a series of bis(dihydroxyphenyl)pyridines via Suzuki coupling of 3,4-dimethoxybenzene-boronic acid with an appropriate dibromopyridine, followed by demethylation in refluxing aqueous HBr. In this poster, progress toward this goal and future plans for evaluation of these compounds will be discussed.

Poster Number: 113

Seven-Step Linear Synthesis of Racemic Nicotine Highlighting the Grubbs’ Ring-Closing Metathesis

Ellie Burns, Winthrop University

Faculty Mentor: Aaron Hartel, Ph.D.

Nicotine is a common alkaloid that is predominantly found in tobacco plants and other members of the Solanaceae family. It is a pharmacologically important molecule due to its known stimulant properties and the potential medicinal benefits of its analogues. Nicotine analogues have previously been identified as having the capability to alleviate symptoms of diseases including Alzheimer’s and Parkinson’s. Racemic nicotine has been produced via a seven-step linear synthesis appropriate for an advanced level academic synthesis lab. The synthesis produced an overall yield of 1.02% and features a Grubbs’ Ring-Closing Metathesis (RCM) reaction in Step 5 for the formation of the pyrrolidine ring.

Poster Number: 113

Seven-Step Linear Synthesis of Racemic Nicotine Highlighting the Grubbs’ Ring-Closing Metathesis

Ellie Burns, Winthrop University

Faculty Mentor: Aaron Hartel, Ph.D.

Nicotine is a common alkaloid that is predominantly found in tobacco plants and other members of the Solanaceae family. It is a pharmacologically important molecule due to its known stimulant properties and the potential medicinal benefits of its analogues. Nicotine analogues have previously been identified as having the capability to alleviate symptoms of diseases including Alzheimer’s and Parkinson’s. Racemic nicotine has been produced via a seven-step linear synthesis appropriate for an advanced level academic synthesis lab. The synthesis produced an overall yield of 1.02% and features a Grubbs’ Ring-Closing Metathesis (RCM) reaction in Step 5 for the formation of the pyrrolidine ring.

Poster Number: 114

Thermodynamics-Based Discovery of New K-La-Zr-O Compounds via Hydrothermal Synthetic Methods

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Thomas Sullivan, Winthrop University

Faculty Mentor: Maria Gelabert, Ph.D.

This project investigates aqueous modeling coupled with mild hydrothermal methods (200 °C, 16 atm) for discovery of new compounds, goals for advanced materials development outlined in SC Vision 2025 and NSF Big Ideas. Innovative luminescent materials, such as scintillators, are needed for opto-electronics and other optical technologies. Hydrothermal methods were performed, with thermodynamic guidance from aqueous speciation calculations in OLI Studio, to look for compounds in the K-La-Zr-O quaternary system. This system choice was inspired by several Na-Y-Si-O compounds previously synthesized by supercritical hydrothermal methods. By altering compositions of reactants, it is possible to generate trace amounts of novel crystals of new stoichiometries. In the previous discovery of Zn2EDTA·2H2O, optimum hydrothermal conditions were just outside of the thermodynamic stability region for ZnO, suggesting that the edges of such stability regions are potential places for discovery work. With OLI Studio, yield diagrams were constructed for the K-La-Zr-O system, with water-soluble metal salts, chelating agent, and base as reactants. Chemical systems readily form thermodynamically stable binary/ternary compounds: in this case, zirconia (ZrO2) and lanthanum hydroxide (La(OH)3). Within Zr and La subsystem yield diagrams, where the concentration ratio of metals is plotted against base concentration, locations just outside of the ZrO2 stability region were targeted for Zr:La ratios of 1:1 and 4:1. Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) revealed polycrystalline morphology with some single crystals (≈50 microns) of hexagonal and greater (6+ sides) geometry containing significant amounts of oxygen, lanthanum, and zirconium, suggesting formation of a lanthanum zirconate compound.

Poster Number: 115

Developing Microfluidic Devices for Assisted Reproductive Technologies

Darien K. Nguyen, Winthrop University

Faculty Mentor: Alireza Abbaspourrad, Ph.D., and Amir Mokhtare, B.S., Cornell University

The gaining popularity of Assisted Reproductive Technologies (ART) such as In Vitro Fertilization (IVF) and Intracytoplasmic Sperm Injection (ICSI) calls for the introduction of more affordable and less tedious processes rather than the typical manual operations. In order for ICSI to occur, the Cumulus Oocyte Complexes (COCs) retrieved from the ovaries must be processed in order to remove the tightly-packed cumulus cells surrounding them. As of yet, this tedious and unstandardized process is being done manually by skilled embryologists, which results in variability and unavailability. The focus of this project is to develop microfluidic devices to denude the COCs for ICSI, in order to reduce the tyranny of manual operations and push toward automated, reproducible operations. These microfluidic devices are fabricated through conventional PDMS microfluidic processes and tested using automated magnetic pumps controlled by a microcontroller. To date, actual microfluidic devices have been developed and successfully tested using particles similar to COCs.

Poster Number: 116

Investigation and Optimization of the Synthesis of the Sphingosine Kinase 1 Inhibitor

Tiffany Dwyer, Winthrop University

Phospholipids such as sphingolipids are main components of the lipid bilayer of the cell membrane. Sphingolipids are bioactive signaling molecules that play roles in cell division, proliferation, and death. Sphingosine kinase-1 (SK1) is an enzyme that regulates levels of sphingolipid metabolites, such as ceramide, sphingosine, and sphingosine-1-phosphate (S1P). In the sphingolipid metabolic pathway, ceramide is metabolized to sphingosine, which is phosphorylated to become S1P through the catalysis of SK1. Ceramide induces cell-cycle arrest and apoptosis, whereas S1P induces cell survival, proliferation, and migration. Malignant, cancerous cells have an overexpression of SK1, which causes over-production of S1P and leads to cancer cell proliferation, increased motility, and metastasis. The balance of ceramide, sphingosine, and S1P can therefore determine the fate of cancer cells. Due to its contribution to cancer progression, SK1 can be targeted in cancer therapy within the sphingolipid metabolic pathway. Inhibition of SK1 would deter cancer proliferation and result in apoptosis of cancer cells, which is the focus of any cancer therapy. A successful in vitro inhibitor, sphingosine kinase inhibitor-1 (SKI-1), was located, but is not an effective in vivo inhibitor due to its hydrophobicity and resulting low bioavailability. Derivatives of this inhibitor have been synthesized and analyzed to ultimately increase hydrophilicity and bioavailability of the parent inhibitor; these derivatives should exhibit the same in vitro effectiveness, as well as increased bioavailability, resulting in a more effective inhibitor in vivo as a possible treatment option in this pathway. The synthetic process used to synthesize derivatives of SKI-1 is being optimized. Previously, the Claisen condensation reaction of the synthetic scheme was optimized by using a microwave reactor. The overall synthesis is currently being further optimized to perform a one-pot synthesis of each derivative using the microwave reactor, and to maximize the yield and purity of the final product.

Poster Number: 117

Artifact Classification and Value Promotion in Makerspaces

Dominique Exley, Winthrop University

Faculty Mentor: David Wilson, Ph.D.; Johanna Okerlund, B.S.; and Madiha Tabassum, B.S., University of North Carolina, Charlotte

As makerspaces are becoming more prevalent, the artifacts produced within them will have an increasing impact on the world. Thus, determining commonalities in what and why makers are creating is important to the promotion and expansion of communities that partake in socially relevant activities. This study analyzes maker artifacts in an attempt to discover underlying latent themes. Topic modelling by means of LDA is used as the primary tool to conduct the analyses. Additionally, attention is placed on the potential to apply these themes to graphic designs, with the purpose of expanding maker activities and further promoting the central values and ideals of Human Centered Design (HCD).

Poster Number: 118

Large-Scale Analysis of HTTP Response Headers

Connor Leyers
Joshua Paytosh
Nolan Worthy

Faculty Mentor: Andrew Besmer, Ph.D.; R. Stephen Dannelly, Ph.D.; and William Thacker, Ph.D.

This paper examines trends in the use of HTTP response headers that relate to security, how long it takes for them to become widely adopted after release, and how quickly they are phased out after deprecation. The data come from the Common Crawl’s monthly web crawls that collect responses from what we can consider to be the entire internet. They are delivered as JSON in WAT format and analyzed in Python on an AWS EMR cluster running PySpark, which allows the analysis of data in parallel across the nodes in the cluster. For the purposes of this research, the entire dataset will be analyzed, as well as a subset representative of Fortune 500 companies. For each website in the dataset, there will be checking for the presence of 16 different HTTP response headers that pertain to security (e.g., X-XSS-Protection). The presence of each header over several months indicates the speed of adoption or abandonment.

Poster Number: 119

A Mathematical Framework of Turbulence in Adaptive Optics

Hannah Elser, Winthrop University

Adaptive optics (AO) is a technology that detects incoming waves that have been disturbed by turbulence and uses mal-formable mirrors to correct for distortion. When waves of light exit the vacuum of space and encounter Earth’s atmosphere, those waves also encounter turbulence, a chaotic fluid motion of air. This turbulent air causes distortion in the light waves. By using a wave sensor to detect incoming waves and a control computer to calculate correction, this can deform the mirror of the telescope to compensate for the distortion and reduce interference, allowing for a clearer image. Here, the present study will decipher and explore the mathematical models critical to AO systems.