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Symposium Proceedings

 

Note: Presentations are grouped by the student’s area of research (based on the faculty mentor’s academic department), not the student’s academic major.

 

Poster Session B: 

9:45 - 10:45 am

Biochemistry and Molecular Biology; Chemistry; and Chemical Engineering (34 posters).

Note: This session features presentations by members of the American Chemical Society Student Affiliates Chapter at OSU.

 

Presentations:

 

B-01       Maison Cook and Emma Kempton

Research Collaborators:  Stephen Kotey, Pei Jia Ng, Sean Gile

Research Presentation Title:  Cloning of Anti-tumor Human Gene SMARCB1/INI1 for the Treatment of Rhabdoid Tumors

Faculty Research Mentor:  Yong Cheng, Biochemistry and Molecular Biology

 

Rhabdoid tumors are malignant tumors found in the kidneys and other soft tissues of adolescents, with the average age of diagnosis between 15 and 24 months. Currently, patients diagnosed with rhabdoid tumors are treated with a combination of surgery, chemotherapy, and radiation therapy. These patients face a survival rate below 25%. The mutations of the SMARCB1/INI1 gene have been found in the majority of rhabdoid tumors including the atypical teratoid rhabdoid tumors (ATRT). Therefore, we hypothesize that the SMARCB1/INI1 protein might be developed as a tumor suppressing protein-based drug for the treatment of childhood rhabdoid tumors. To test our hypothesis, we cloned the SMARCB1/INI1 gene from the human genome into a protein expression vector (pET28a). The recombinant human SMARCB1/INI1 protein will be isolated from E.coli cells using Ni-NTA resin-based chromatography and the anti-tumor activity of purified human SMARCB1/INI1 protein will be analyzed in tumor cell culture in vitro in future study.

 

B-02       Avery Ethridge

Research Presentation Title:  Application of the Next Generation DNA Sequencing Technique in COVID-19 Vaccine Development

Faculty Research Mentor:  Yong Cheng, Biochemistry and Molecular Biology

 

According to the United States’ Center for Disease Control and Prevention (CDC), SARS-CoV-2, the virus that causes COVID-19, is a type of corona virus that most often causes respiratory symptoms. In the past two years, SARS-CoV-2 virus is causing the worldwide and is still a big public health threat. Due to this emergent issue, scientists are developing protective vaccines to stop the spread of the virus. As a first step, the scientists need to identify different viral variants that cause COVID-19 pandemics during certain seasons. Next generation sequencing (NGS) is a state-of-the-art DNA sequencing technique that can be used to capture a broader range of mutations and work more efficiently than any past sequencing techniques. Since its introduction to the biomedical research, NGS has been used to define the genomes of pathogens and trace sources of infection outbreaks. In this study, we carried the research to pursue the application of NGS technique in the development of novel and effective COVID-19 vaccines.

 

B-03       Charlcie Gatewood

Research Collaborators:  Stephen Kotey, Xuejuan Tan 

Research Presentation Title:  Mycobacterial Killing Assay in Macrophages

Faculty Research Mentor:  Yong Cheng, Biochemistry and Molecular Biology

 

Mycobacterial killing assay is an important method to determine mycobacterial pathogenesis and antimycobacterial response in host cells. In our study, we analyzed the survival of Mycobacterium abscessus in mouse macrophage cell line, Raw 264.7 cells. Mycobacterium abscessus survival in macrophages is measured through a multiple step process: (1) Infection of the cells with Mycobacterium abscessus for 1 hour, 24 hours and 72 hours, (2) Plating cell lysates on agar plates, (3) Incubating plates at 37oC,  and (4) Counting colonies on the plates.  We study Mycobacterium abscessus survival in host cells to gain knowledge on this disease and how it affects patients with cystic fibrosis and chronic obstructive pulmonary disease.  Prevalence of this disease has increased over the years, especially drug-resistant mycobacterial strains. It becomes important to understand the interaction between the host and Mycobacteria. In our mycobacterial killing assay, we observed that Mycobacterium abscessus can adapt to grow successfully in Raw 264.7 cells.  Further studies are needed to halt and reduce Mycobacterium abscessus growth within host cells.

 

B-04       Carlyn Guthrie

Research Collaborators:  Xuejuan Tan, Lin Liu

Research Presentation Title:  Developing a Bacteria-based Covid-19 Vaccine

Faculty Research Mentor:  Yong Cheng, Biochemistry and Molecular Biology

 

Over the past two years, the Covid-19 virus has been one of the top public health threats in the world. This fast-spreading virus quickly caused a pandemic that has caused more than 5 million deaths around the world. To help combat the disease, pharmacological companies, such as Pfizer-BioNTech and Johnson and Johnson, have created vaccines. Pfizer-BioNTech designed a vaccine based on the mRNA from the Covid-19 virus genome, while Johnson and Johnson designed a vaccine based on a viral vector. Despite these current vaccines, Covid-19 is still a threat to society, so new types of Covid-19 vaccines are needed to help stop the pandemic and prevent future pandemics. In this study, I will create a novel Covid-19 vaccine that has not yet been studied. This vaccine will incorporate the gene of the Covid-19 spike protein from the virus genome and I will transform it into Mycobacterium bovis BCG (M. bovis BCG). The resulting transgenic M. bovis BCG will be used to vaccinate mice. I expect that the transgenic M. bovis BCG will activate a protective immunity against the Covid-19 infection in mice.

 

B-05       Giselle Johnson and Tatum Norwood

Research Collaborators:  Pei Jia Ng, Stephen Kotey, Sean Gile, Sushim Gupta, John Gustafson

Research Presentation Title:  The Application of Next-Generation DNA Sequencing Technique in Identifying Antibiotic-Resistant Genes in Bacteria Isolates

Faculty Research Mentor:  Yong Cheng, Biochemistry and Molecular Biology

 

Next-generation sequencing, also known as massive parallel sequencing, is a high throughput approach to DNA sequencing. This technology has revolutionized biological studies in the past two decades as it allows scientists to conduct research in the lab by determining specific orders of nucleotides in the genomes. It also gives them the opportunity to look into specific regions in the genome that play critical roles in disease progression and environmental adaptation. In this experiment, we learn the technique of how to prepare a DNA library that will be analyzed in the Illumina next-generation DNA sequencing platform. To better understand the potential application of next-generation DNA sequencing techniques, we will use this technique to identify the bacterial DNA genes that cause antibiotic resistance in bacteria that were isolated from Wastewater Treatment plants.

 

B-06       Ashton Self

Research Collaborators:  Carlyn Guthrie,  Xuejuan Tan

Research Presentation Title:  Understanding the Mechanism of Anti-mycobacterial Responses in Host Cells

Faculty Research Mentor:  Yong Cheng, Biochemistry and Molecular Biology

 

Non-tuberculosis Mycobacterium (NTM) is becoming more prevalent today with increasing infections in people with lung conditions such as chronic obstructive pulmonary disease (COPD) and cystic fibrosis. NTM is often drug-resistant and quickly evolves to survive against new antibiotics, making it hard to find a reasonable and effective treatment plan. The goal of this study is to find host factors that positively regulate anti-mycobacterial response, and further understand the corresponding regulatory mechanism in host cells during NTM infections. We hope that our study can facilitate the development of novel and effective anti-mycobacterial drugs, especially for drug-resistant NTM. To pursue our goal, we will use Mycobacterium abscessus, one type of NTM, and mouse macrophage cell culture as our study model.

 

B-07       Maicel Sims

Research Collaborators:  Stephen Kotey, Xuejuan Tan, Yong Cheng

Research Presentation Title:  DNA Transformation in Mycobacterium abscessus

Faculty Research Mentor:  Yong Cheng, Biochemistry and Molecular Biology

 

DNA transformation is an important process for the overall study of bacterial genetics and is commonly used in molecular biology and microbiology. The process consists of a bacterial cell taking up extracellular genetic material from the environment. Transformation requires four steps- preparation of competent cells, transformation, cell recovery period, and cell plating. In order for a bacterial cell to take up genetic material it has to be competent. To achieve competence, bacterial cells undergo either heat shock or electroporation; which depends on the overall experimental goal. If heat shock is the method, the chemically competent cells are then mixed with plasmid DNA and exposed to a high temperature. If the electroporation method is chosen, an electroporator is used to expose the electrocompetent cells and DNA to a pulse of a high voltage electric field. After transformation, cells are recovered in a certain bacterial growth liquid medium and then plated out on agar plate containing selection antibiotics, ensuring a successful transformation. The goal of my experiment was to successfully generate a plasmid in E.coli cells and then transform it into a bacterial pathogen, Mycobacterium abscessus. For this experiment, I used the electroporation method to prepare Mycobacterium abscessus competent cells and kanamycin-containing plates to identify the successful transformants. Mycobacterium abscessus strains that resulted from this experiment can be used for future studies involving fluorescence microscopy.

 

B-08       Lydia Stinson

Research Collaborators:  Charlie Vermiere, Xuejuan Tan, Yong Cheng

Research Presentation Title:  Understanding the Interaction between Nontuberculous Mycobacteria and the Host in Cystic Fibrosis

Faculty Research Mentor:  Yong Cheng, Biochemistry and Molecular Biology

 

Nontuberculous mycobacteria (NTM) are environmental bacteria and can be found in soil, water, and dusts. However, they can cause lung diseases in certain populations with pre-existing lung conditions such as cystic fibrosis and chronic obstructive pulmonary disease (COPD). NTM employs a variety of mechanisms for their survival in the host, such as arresting phagolysosome maturation, cell wall component alteration, and attenuating T cell activation to interfere with the host’s protective immune response. In this study, I am working with the senior lab members to understand the mechanism by which Mycobacterium abscessus, one type of NTM strains, causes active lung infections in cystic fibrosis patients. We hope that our research can aid in the medical approach and treatment plans of NTM infections.

 

B-09       Charlie Vermeire

Research Collaborators:  Xuejuan Tan, Stephen Kotey, Yurong Liang, Lin Liu, Yong Cheng

Research Presentation Title:  The Role of Mycobacterium abscessus-Infected-Macrophage-Released Exosomes on Host Immune Responses

Faculty Research Mentor:  Yong Cheng, Biochemistry and Molecular Biology

 

Host immune response may follow several avenues of defense against invading pathogens, including the production of proinflammatory cytokines, phagocytosis by non-specific leukocytes, and activation of adaptive immune cells. While each response differs in cellular mechanism, all require host immune cell access to components of invading pathogens. The antigens of extracellular pathogens are readily available to host immune cells during infection but are not so easily acquired from intracellular pathogens whose antigens remain within host cells. To compensate, recent studies suggest that intracellular pathogenic material is delivered to immune systems via the formation and release of extracellular vesicles (EVs), such as exosomes, by infected host cells. These membrane-enclosed packages of bacterial components may contain cell wall antigens and several species of RNA and appear to modulate host immunity. While it is well- supported that exosomes released by macrophages infected with Mycobacterium tuberculosis or non-tuberculosis mycobacteria (NTM) play a role in host immune response, the extent to which they do so remains unclear. This study is distinct in its aim to determine the role of exosomes released by Mycobacterium abscessus (M.abscessus)-infected macrophages on host immune responses to NTM infections. To do this, we prepared exosomes from macrophage cell culture in vitro, then analyzed then using biochemical and immunological tools.

 

B-10       Brinkli Abbitt

Research Collaborators:  Jindal Shah

Research Presentation Title:  Discovering Environmentally Friendly Corrosion Inhibitors Using Quantum Chemical Calculations

Faculty Research Mentor:  Jindal Shah, Chemical Engineering

 

Ionic liquids are molten salts that remain liquid at temperatures above room temperature. They are also referred to as designer solvents because of their customizability. Ionic liquids are composed of an asymmetrical cation and anion which change characteristics depending upon the cation-anion mixture and the alkyl chain length or ring position, etc. A few important consistent characteristics to note are their low volatility, chemical stability, and almost non-existent vaporization point which gives them environmentally friendly characteristics that contrast that of modern corrosion inhibitors. The combination of these properties has led many researchers to invest in experimenting and taking data on ionic liquids’ many applications. I am currently researching a range of useful imidazolium-based ionic liquids to determine the most efficient Ionic Liquid mixtures with respect to the corrosion inhibition of important materials. Corrosion, or the deterioration of a material due to environmental exposure, is a pervasive obstacle that industries ranging from oil and gas, power generation, chemical and petrochemical, water storage, etc. are investing in eliminating. By mitigating the impact of corrosion on materials we could increase economic growth, operations, and safety not only in the US but across the globe. Because designed ionic liquids are only limited to the imagination, there must be a more efficient way to identify their properties than trial and error experimentation. Ionic liquid experiments can quickly become time consuming and costly because of the expensive solvents themselves and machinery used to analyze and test their properties. Using quantum chemical calculations, I catalog data on ionic liquids regarding corrosion resistance and conduct electronic structure calculations of the cation-anion pairs. My computational data along with previously collected data from other researchers will then be used to enhance an Artificial Neural Network model or ANN’s ability to predict useful corrosion inhibitors based on their cation-anion pairs. This data accrued from the ANN will be beneficial to researchers because it will cut down on time and experimental costs as well as pave a new way to analyze ionic liquids for other applications.

 

B-11       Connor Allen

Research Collaborators:  Allan Katende, Robert Krumm, Xiong Fengyang, Cody Massion, Dustin Crandall

Research Presentation Title:  Subsurface Engineering of Conductive Fractures in Caney Shale, Southern Oklahoma: A Step Towards Energy Transition

Faculty Research Mentor:  Mileva Radonjic, Chemical Engineering

 

The Caney Shale is an emerging unconventional hydrocarbon resource in southern Oklahoma that contains a strong oil and natural gas drive. To produce hydrocarbon from low permeability rocks, a network of hydraulic fractures is engineered via large volume, high pressure injection of sand rich brines. However, development has been hampered largely because the unknown geomechanical properties of clay-rich ductile shales can limit the fracturing of such formations. My research is focused on the mechanism of proppant embedment into fracture walls that leads to fracture closure and reduction in permeability, so that hydraulic fracturing fluids that enhance hydrocarbon production from Caney Shale can be developed. Firstly, the samples were prepared by extracting eight plates (7x2x0.5inches) from a drilled 4-inch Caney core (Figure 1a), with each four-plate set from a ductile and reservoir (brittle) region, respectively. These plates were then used to sandwich a proppant sand pack and loaded at high-temperature and high- pressure to mimic fracture behavior under reservoir conditions of 210°F and 2,000 to 12,000 psi, measuring the fracture permeability over six weeks. This created proppant embedment craters that were further analyzed using various techniques, including a Leica DVM6 Digital Microscope utilizing Las X software to generate 3D scans, topography maps, and line profiles to quantitatively analyze the degree of proppant embedment (Figure 1b). Results showed obvious proppant embedment along the surfaces of shale plates under high pressure. However, when the fracture closure pressure declined from 12,000 to 4,000 psi, the fracture permeability in the ductile region was increased, while the brittle regions remained unchanged. This could have an implication on refracturing as a secondary attempt for enhanced fracture permeability. The findings in this study first and foremost will contribute to safe, economic, and responsible producing of the Caney Shale. On a fundamental level, the project will contribute to the understanding of Ductile Shales for a variety of applications, from hydraulic fracturing and carbon and hydrogen subsurface storage to the potential contribution of shales to plugging and abandonment.

 

B-12       Mejalaa Mega Jayaseelan

Research Collaborators:  Heather Fahlenkamp, Taylor Conley

Research Presentation Title:  Testing the Infectivity of Respiratory Syncytial Virus on Small Airway Epithelial Cells

Faculty Research Mentor:  Heather Fahlenkamp, Chemical Engineering

 

Respiratory syncytial virus (RSV) is one of the most infectious viruses among the pediatric population. Severe cases of pulmonary infection due to RSV can lead to asthma and other respiratory issues later in life. To better understand the immune response to RSV, we have developed a 3D-Human Tissue-Engineered Lung Model (3D-HTLM) consisting of the key cell types involved in the pulmonary immune response process. These cells include small airway epithelial cells (SAECs), human pulmonary microvascular endothelial cells, and human pulmonary fibroblasts. The overall goal of this study was to establish the 3D-HTLM as a representative model of lung cells in vivo by investigating the infectivity of SAECs with varied concentrations of RSV. SAECs were infected with turboRFP-labeled RSV at 10 and 15 multiplicity of infection (MOI) for 24, 48, and 72 hours. The infected cells were then fixed, stained via the immunohistochemistry staining technique (IHC), and observed under a confocal microscope. The results suggest that the SAECs within the 3D-HTLM are infected with RSV, indicating the potential of utilizing the 3D-HTLM for studying human immune responses to RSV.

 

B-13       Alexander Roubik

Research Collaborators:  Mileva Radonjic, Barry Dean

Research Presentation Title:  Impact of Well Completions Parameters on Oil & Natural Gas Returns in the Caney Shale of Oklahoma

Faculty Research Mentor:  Mileva Radonjic, Chemical Engineering

 

The analysis conducted over the course of this study focused on the effects of fluid and proppant volumes on the estimated ultimate return (EUR) in barrels of oil equivalent (BOE) of Caney Shale wells in the South Central Oklahoma Oil Province (SCOOP). Data on 53-Caney Shale wells was available for analysis. The data was refined to focus on wells with similar perforated lateral lengths and BOE EURs in order to establish a baseline. The purpose of this was to determine if proppant and fluid use was consistent with the BOE EUR across the data set. The findings of this study revealed no linear trends between fluid and proppant use and the BOE EUR in the wells analyzed. Possible reasons for this may include difference in mineralogy, reservoir heterogeneity, difference in target zone drilled, or other factors unknown at this time.

 

B-14       Karley White

Research Collaborators:  Taylor Do, Gibran Ali, Heather Fahlenkamp

Research Presentation Title:  Determining the Effect of Respiratory Syncytial Virus on the Barrier Integrity of Cell Layers in a Three-Dimensional Human Tissue Lung Model

Faculty Research Mentor:  Heather Fahlenkamp, Chemical Engineering

 

According to the World Health Organization, respiratory syncytial virus (RSV) causes approximately 34 million cases of acute respiratory infections annually. A three-dimensional human tissue lung model (3D-HTLM) has been engineered to observe the effects of RSV infection on cell layer function and behavior. This project analyzed the barrier integrity of cell layers within the 3D-HTLM in response to RSV infection. Transepithelial electrical resistance (TEER) is a quantitative technique that uses electrical currents to measure the barrier integrity of cell layers and monitor cell layer behavior through stages of development. Different variations of the 3D-HTLM consisting of a collagen base, fibroblasts, small airway epithelial cells, and human pulmonary microvascular endothelial cells were infected with RSV. The barrier integrity of the cell layers within each model was determined by taking TEER measurements 24, 48, and 72 hours after RSV infection. Results indicate a decrease in barrier integrity related to the degradation of cell layers within the 3D-HTLM after RSV infection. Analyzing the barrier integrity of cell layers is important in understanding viral interactions with the lung epithelium, and it can provide information to aid in the advancement of treatments for RSV infection.

 

B-15       Catrina Aguirre

Research Presentation Title:  Optimization of the Synthesis of Substituted 1,2,4-Triazoles

Faculty Research Mentor:  Jeanne Bolliger, Chemistry

 

Cyclic molecules containing nitrogen, oxygen and sulfur are common in nature, ranging from sugar molecules, over alkaloids to the bases holding together the two strands of our DNA through hydrogen bonding. Many compounds with biological activity used for treatment of common diseases or infections also contain at least one heterocycle in their structure. For example, the antibiotic penicillin has a nitrogen containing heterocycle while the antipsychotic drugs Zyprexa and Seroquel both have sulfur and nitrogen atoms incorporated in their rings. Fluconazole is an antifungal medication which contains two 1,2,4-triazole rings, the topic of the current presentation. The target of our research is to improve a previous synthesis of substituted 1,2,4-triazoles developed in the Bolliger lab. By using different reaction precursors and developing a different pathway to the desired molecules, we aim to both improve the yields of these reactions as well as make the purification of the products easier. We will compare the outcome of these two alternative synthetic routes and test the new procedure with various amine starting materials.

 

B-16       Kaitlin Ashcraft

Research Collaborators:  Spencer Pitre, Kayla Beagles

Research Presentation Title:  Hantzsch Amides for the Selective Reduction of Michael Acceptors

Faculty Research Mentor:  Spencer Pitre, Chemistry

 

The main goal of this research study is to develop a new method to selectively reduce electron-deficient alkenes, even in the presence of electron-rich alkenes. For example, the use of a protecting groups could be avoided if the reduction could occur selectively, reducing the number of synthetic steps. In initial studies from our group, we focused on developing a new method for the reduction of Michael acceptors, working primarily with benzyl acrylate. This method is photocatalyzed by Vitamin B12 and 4CzIPN and uses Hantzsch ester as the reducing agent. This method was successful; however, it generated a pyridine byproduct that was difficult to be washed out and separated. In this work, instead of using Hantzsch ester as the reducing agent, we will be examining different Hantzsch amides as reducing agents, as these are expected to be easier to remove after the reaction, simplifying purification. The synthesis of different Hantzsch amides and their ability to act as reducing agents for the reduction of benzyl acrylate will be presented.

 

B-17       Alex Bias

Research Collaborators:  Christopher Fennell

Research Presentation Title:  Single-Point Modeling of Water Using Spherical Harmonics

Faculty Research Mentor:  Christopher Fennell, Chemistry

 

A single-point model for molecules is a benefit to computational research because it will allow higher efficiency in simulations and calculations. Using spherical harmonics allows a single-point model to have directionality, which is important in appropriately modeling certain molecules. By targeting only a few variables such as hydrogen bond strength and size, spherical harmonic water approximates the intermolecular interactions found through experimental data very well. Using a more narrow interaction function allows for spherical harmonic water to create hydrogen bonds in a more realistic way, creating a more organized structure which is expected based on experimental data.

 

B-18       David Bruce

Research Collaborators:  Christopher Fennell

Research Presentation Title:  Characterization of Driving Forces for Protein Folding in Model Systems

Faculty Research Mentor:  Christopher Fennell, Chemistry

 

Protein secondary structure is of utmost importance to proper functioning of biological systems. Secondary structure is largely mediated by intra-molecular hydrogen bonding and is heavily influenced by the conditions of a system. To further investigate the interactions that lead to common structural motifs such as alpha helices and beta sheets, systems were constructed housing simple peptides in aqueous conditions, and biased sampling was conducted to outline a free energy landscape and elucidate the energetic motivations involved in protein folding and adoption of these confirmations. Upon addition of urea, features of the free energy surface were enhanced, indicating rigidification of secondary structure, providing insight for the processes that occur in the denaturing of proteins prior to excretion in living organisms.

 

B-19       Elevia Bruce

Research Collaborators:  Katrina Betz, Colton Calvert, Elijah Schnitzler

Research Presentation Title:  Separations of Biomass Burning Organic Aerosol by Polarity using Water and 1-Octanol

Faculty Research Mentor:  Elijah Schnitzler, Chemistry

 

Biomass burning organic aerosol (BBOA) in the atmosphere absorbs and scatters solar radiation and enhances cloud formation, impacting climate directly and indirectly. BBOA is a complex mixture of many organic compounds, with a wide range of physical and optical properties, including polarity and absorptivity. Furthermore, both aqueous and organic phases are present in atmospheric aerosol particles, so BBOA components may partition to different phases depending on polarity. Consequently, experiments were conducted to determine the distribution of BBOA across a range of polarity fractions and to determine which fractions contribute the most to visible-light absorption. BBOA was generated in the laboratory from smoldering pine and eastern red cedar species, collected on filters, and then extracted in water to give 100 mL solutions with mass concentrations of BBOA of about 1 mg mL-1. Then, 20 mL of this aqueous solution was added to 0, 0.2, 2, 20, and 200 mL volumes of 1-octanol in separatory funnels, thoroughly mixed, and set in the fume hood for 24 hr. Afterwards, the absorbance, mass, and mass absorption coefficient were determined for the polarity fraction remaining in each aqueous phase, using a fiber-optic-based UV-Vis spectrometer and a scanning mobility particle sizer (SMPS). The UV-Vis measurements show that absorbance was reduced for aqueous fractions to which higher volumes of 1-octanol had been added, and the SMPS measurements indicate that large mass quantities partitioned to the organic phase with the addition of 1-octanol. These results provide insights into the distribution of BBOA mass and absorptivity across a wide range of molecular polarity fractions.

 

B-20       Keaton Cissell

Research Collaborators:  Roshini Hanumanthu

Research Presentation Title:  Contextualizing Lutidine Salts in Photocatalytic, Substitution Reactions

Faculty Research Mentor:  Jimmie Weaver, Chemistry

 

Formation of new carbon-carbon bonds lies at the heart of organic chemistry. Radical intermediates are particularly well suited for reaction with a host of reaction partners to yield new carbon–carbon bonds and alkyl halides are the typical choice for precursors. Unfortunately, the difficulty of converting various alkyl halides to carbon-centered radicals varies dramatically depending on the structure. Thus, a method that could facilitate and normalize the reduction of the alkyl halides would be advantageous as it would allow this ubiquitous class of molecules to become more synthetically useful. Previous research from the group has shown that collidinium salts can be made from alkyl halides and that these salts are excellent radical precursors for photocatalytic reactions because they normalize the reduction potentials. This was demonstrated by the development of a Giese addition to electron poor alkenes to give the corresponding alkylated alkane. The collidinium salts prevented side reactions that occurred in other salts, leading to higher yields and other positive reaction attributes; however, the ortho methyl groups hindered the nucleophilicity. This reduction in nucleophilicity presented a major drawback because it made creating the salts in situ challenging. In most cases, the synthesis of the collidinium salts required high temperatures and long reaction times which limited the range of potential substrates. In this work, we are exploring lutidine salts made from the corresponding alkyl halide and lutidine (m, m- dimethylpyridine) as viable alternatives. They exhibit similar desirable properties in terms of redox potential but have a reduced steric demand which is expected to enhance the precursor’s nucleophilicity and enables more facile salt formation in situ. Importantly, the undesired side reaction tends to attack at the ortho and para-position and substitution at the meta-position appears to be sufficient to halt this process. Investigation of lutidine salts under photocatalytic conditions is expected to ultimately provide a new avenue to expand the utility of alkyl halides through a dual catalysis sequence involving both photo- and nucleophilic-catalysis.

 

B-21       Rachel Crittell

Research Collaborators:  Jeanne Bolliger, Rehema Nakiwala, Scott Hutchinson

Research Presentation Title:  Syntheses of Nitrogenous Heterocycles

Faculty Research Mentor:  Jeanne Bolliger, Chemistry

 

For many years, research on heterocycles has been an essential part of organic research because of their ability to be used in medications. Our research is examining ways of optimizing and expanding on past methods from Bolliger lab to increase the yield of the product and minimize the formation of unwanted by-products. Using a literature procedure, we will initially prepare diaryliodonium salts containing a variety of substituents such as bromine, methyl, and methoxy. In a second step, we will synthesize N-aryl substituted compounds. This process will be accomplished by using diaryliodonium salts that had been synthesized in the previous step. While many of these compounds have been previously synthesized by Bolliger group, this research will help to optimize the yield of these syntheses. The third aim is to develop an alternative method for the next reaction step. This is to avoid the production of unwanted by-products currently observed in the product. The final objective of this research is to optimize the final step of this reaction sequence, an oxidative cyclization carried out in the presence of iodine and a base. Various reaction conditions will be tried and compared with one another. One investigation will include studying how the amount of iodine used to catalyze the reaction will affect the yield of the product. Iodine is a key reagent required for the reaction; however, excess iodine leads to a by-product that is extremely difficult, costly, and time-consuming to remove from the desired product. Another optimization that is being considered is the testing of the effect of different bases such as potassium tert-butoxide, DBU, and triethylamine to examine whether their use will optimize the oxidative cyclization. This research is vital as it will provide improved synthetic methods to produce more of these compounds at higher yields. Since many of the target molecules have structural similarities with biologically active compounds that are used for a variety of conditions, such as cancer, anxiety, and fungal infections, we hope that with our research we will pave the pathway to a new class of compounds.

 

B-22       Rachel Dolan

Research Collaborators:  Michael Harris, James Bryce

Research Presentation Title:  Using Lipid Nanodiscs for the in vitro Glycosylation of Membrane Proteins

Faculty Research Mentor:  Gabriel Cook, Chemistry

 

Membrane proteins are involved in a number of human diseases are important to study. Due to the fact that these proteins are, by nature, insoluble in aqueous solutions, they require detergent or lipid environments that resemble cell membranes to remain soluble. Nanodiscs can be used to prevent these proteins from precipitating. Nanodiscs are patches of phospholipid bilayer that is encircled by membrane scaffold protein and mimic the thickness of the human cell membrane. This allows for membrane proteins to be studied in a native-like environment. In our lab, we study a specific group of proteins that are post-translationally modified. These proteins are glycoproteins which have sugar groups attached to their sidechains. It is also important to understand how proteins change when a sugar is attached to them. This will be examined by first inserting the membrane protein into nanodiscs and then attempting to glycosylate them using in vitro glycosylation with the enzyme N-Glycosyltransferase (NGT). We will show that membrane proteins that are inserted into nanodiscs can be glycosylated using these methods.

 

B-23       Megan E Hays

Research Collaborators:  Santosh Adhikari

Research Presentation Title:  Fabrication, Characterization and Optimization of Electrically Conductive Fibers

Faculty Research Mentor:  Toby Nelson, Chemistry

 

Organic conductive inks are useful for imparting semiconductive properties onto common organic fibers such as cotton, polyester, and silk. Our group has developed a conductive ink using single-walled carbon nanotubes (SWCNTs) suspended in a solution with regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT).  The properties of these materials lend towards easily fabricating biocompatible, lightweight, and low thermoconducting electrodes.  In recent years, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) has been utilized as an low-cost, more conducive alternate to P3HT. This research study will assess the performance of PEDOT:PSS conductive inks and fibers in comparison to the previously prepared conductive materials.

 

B-24       Emily Forster

Research Collaborators:  Gabriel Cook, Austin Anderson, Michael Harris

Research Presentation Title:  Optimization of TEV protease efficiency for improved use in membrane protein expression and purification

Faculty Research Mentor:  Gabriel Cook, Chemistry

 

Tobacco Etch Virus (TEV) protease is a useful enzyme that plays an important role in the cleavage of fusion proteins. TEV cuts the protein backbone between the Q and G residue of the sequence ENLYFQG. The sequence is normally inserted between a leader or tag sequence and the protein of interest. Our usage of TEV is important for the purification of membrane proteins that are unstable unless expressed with a specific protein leader and for membrane scaffold protein (MSP) which requires a protein tag for its purification. Refining the cleavage step in the membrane protein and MSP purification process requires the optimization of TEV growth and storage. One limitation of TEV is its tendency to precipitate in solution shortly after purification. To combat this limitation, we concentrated pure TEV and stored these samples in the -80 ℃ freezer. Using our concentrated samples, we tested TEV’s ability to cleave a fusion sequence of MSP after long term storage at various time increments. We have found uncompromised effectiveness in TEV’s ability to cleave samples of MSP after four months of storage. While we will continually test the activity of our concentrated and frozen TEV samples, our current results show a promising method to store TEV which could allow for its maximized use in the laboratory.

 

B-25       Luke Henke

Research Presentation Title:  Molecule Construction for Modeling Packing in Amorphous Solids

Faculty Research Mentor:  Christopher Fennell, Chemistry

 

One of the challenging concepts in chemistry to grasp is atomic and molecular packing. This is especially true for non-crystalline solids which have no repeating structure. In this work, we seek to rapidly and accurately generate physical molecular models that encode the conformational diversity needed for informative experiments in molecular packing. These molecular models are 3D printed representations of real molecules, scaled up and designed to reproduce the critical features of molecular shape. We built a tool and experimental pipeline for creating and producing printable 3D models of molecules from molecular simulation orientation and position data. We find that these printed model molecule systems s capture the connection between molecular shape and material properties and are useful for educational demonstrations.

 

B-26       Sunghee Jin

Research Collaborators:  Jeanne L. Bolliger

Research Presentation Title:  New synthesis of sulfur heterocycles for bioconjugation

Faculty Research Mentor:  Jeanne Bolliger, Chemistry

 

Heterocycles are common in nature, ranging from alkaloids to the bases holding together the two strands of our DNA through hydrogen bonding. Heterocyclic compounds are also important for medicinal chemists as the majority of active pharmaceutical ingredients contain at least one heterocycle in their structure. Additionally, many new drugs on the market are bioconjugates which are organic molecules linked to biomolecules such as proteins. The target of our research is to prepare new sulfur-containing heterocycles which contain the functional groups that allow covalent binding to biomolecules using a so-called “click” reaction. In this case we will use the Copper catalyzed Azide-Alkyne Cycloaddition (CuAAC) because it has been shown to be biocompatible. In this presentation, we will show a new synthesis leading to our desired sulfur-heterocycle precursors. Using these precursors, we will optimize first the cyclization conditions. In a second step. we will develop a procedure to link these heterocycles to proteins by using a model amino acid derivative.

 

B-27       Troye Jirka

Research Collaborators:  Katrina Betz

Research Presentation Title:  Photoreaction of Biomass Burning Brown Carbon

Faculty Research Mentor:  Elijah Schnitzler, Chemistry

 

Biomass burning organic aerosol (BBOA) significantly affects the radiation balance of Earth’s atmosphere due to its scattering and absorption of light and its influence on cloud formation through its tendency to absorb water. BBOA is composed of a wide range of organic compounds with many different oxygenated functional groups and, in turn, varying polarities, which affect its hygroscopicity and its distribution between organic and aqueous phases in individual particles. In this project, we explore light-driven processing of BBOA from pine wood in the aqueous phase using a photoreactor. Changes in absorbance are measured via a UV-vis spectrometer. Exposure to light increases absorbance due to both dissolved chromophoric products of functionalization and insoluble colloidal particles formed from oligomerization. The size distribution of colloidal particles is determined using a scanning mobility particle sizer. Furthermore, changes in absorbance after light exposure continue in the dark, suggesting a role for long-lived organic radicals in the aging of BBOA in the atmosphere. 

 

B-28       Muhammad Khan

Research Collaborators:  Sulthana Shoukath, Jimmie Weaver

Research Presentation Title:  Self Assembly of Molecules (SAMs) on gold surfaces

Faculty Research Mentor:  Yolanda Vasquez, Chemistry

 

Benzocycloheptene (BC7) containing thiol molecules were used to produce SAMs on Au surfaces and characterized by XPS. The XPS analysis of BC7 Au SAMs revealed the presence of functional groups on the surface which would expand our ability to use BC7 SAMs on Au surfaces for further photo click reaction with various azide-carrying drug molecules, proteins, and fluorophores. These substrates can be further developed for imaging, detection, sensing, and other biomedical applications.  As a proof of concept, photocatalytic click reaction was performed on BC7-thioacetate (off-substrate) with various azide substrates before attempting the reaction on BC7 SAMs on Au surfaces. Click derivatized BC7 thioacetate was successfully characterized by ATR-FTIR and HRMS studies.

 

B-29       Crest Koemel

Research Collaborators:  Tyler Fleske, Erik Lantz

Research Presentation Title:  Formation of Quaternary Carbon Centers Via Photocatalysis

Faculty Research Mentor:  Jimmie Weaver, Chemistry

 

Many biologically active drugs possess structures that only a few reactions produce.  The ability to access precursors and manipulate them in synthetic routes is normally only done with a small set of viable reactions. The aim of our study is to develop the application of photocatalysts and visible light as another tool for the chemists to use to activate precursors in new enabling ways. The idea is we expose a photocatalyst to visible light which is energetically excited. We then use the energy that our catalyst absorbed to activate our precursors. Specifically, when our photocatalyst is irradiated with blue light it becomes electronically energized and it transfers its energy to our substrate. This essentially moves our molecules up an energetic hill, where we design a reaction pathway for it to roll down. This means we can coerce our precursors to take reaction paths (or hills) that are less accessible, if even possible.  Our efforts have focused on probing different reaction parameters in order to optimize the yield, reaction selectivity, and minimizing the time required for the reaction.  Additionally, we consider other aspects of the reaction that may impact the overall process such as the ease of product isolation from the reaction mixture which can impact how green the process is. To understand the reaction, we have synthesized an array of different molecules as precursors. We then add trace amounts of photocatalysts and bathe them in blue light which is effectively an expensive, non-destructive reagent, which makes the process particularly green. We monitored the conversion of our material to product, determine the structure of the product, and evaluate the ease/cleanliness of the reaction. The reaction appears to be quite versatile and works with several substrates. Suggesting that the reaction holds the potential to be a useful application in the chemist’s tool kit, which could lead to more options for drug and pesticide development, changes to existing synthetic routes, and many more applications. Our goal is to complete the development of this reaction so that it may be shared and applied broadly to enable other scientific endeavors.

 

B-30       Adam McBride

Research Presentation Title:  Effect of Diversity in Molecular Simulations of Liquids

Faculty Research Mentor:  Christopher Fennell, Chemistry

 

The goal of our project is to develop more effective models to represent matter through exploring different variables that contribute to a system of molecule’s thermodynamic properties. We looked at variables such as the charge, size, and dispersion attractiveness of general particles to develop models that help calculate properties such as the diffusion coefficient, the enthalpy of vaporization, dielectric constant, and other useful thermodynamic properties. This is done by systematically performing computer simulations of van Der Waals and simple dipolar molecule systems and mixtures. The basis of these investigation provides a general map of how microscopic qualities of particulate systems directly affects the accurate modeling of larger and more complex materials important to diverse industries such as pharmaceutical, agricultural, and environmental.

 

B-31       Mary McKee

Research Collaborators:  Spencer Pitre

Research Presentation Title:  4-Alkyl-1,4-Dihyropyridines: Secondary radical formation using Visible Light Irradiation

Faculty Research Mentor:  Spencer Pitre, Chemistry

 

4-Alkyl-1,4 Dihydropyridines (DHPs) bearing alkyl substituents at C4 can serve as precursors to carbon-centered radicals. Normally, there are two ways that radicals are formed from these precursors. The first is by using a photocatalyst to oxidize the DHP. Alternatively, radicals can be generated through direct excitation of the DHP in the presence of an oxidant. In this work, we present report the first generation of carbon-centered radicals in the absence of both a photocatalyst and an oxidant. In presence of a suitable base, such as potassium tert-butoxide, the 4-alkyl-DHP can undergo deprotonation to form the corresponding anion, resulting in a substantial redshift in the absorption. This redshift allows for direct excitation of the 4-alkyl-DHP anion by blue LED irradiation, resulting in homolysis at the C4 position and generation of a carbon-centered radical. The generation of secondary alkyl radicals by direct visible light excitation of 4-alkyl-DHP for carbon-carbon bond formation will be presented.

 

B-32       Wyatt Xavier Miller

Research Collaborators:  Nima Noei

Research Presentation Title:  Synthesis and characterization of tridentate NCO ligands

Faculty Research Mentor:  Laleh Tahsini, Chemistry

 

Many chemical reactions require catalysts, which allow for lower temperature reactions, increase the speed of reactions, and so on. Catalysts are essential for many chemical reactions making certain reactions feasible, cost efficient, and time efficient. The importance of catalyst vary based upon a variety of factors. In cross-coupling reaction however catalyst are extremely important as discussed by Ponnam Devendar, Ren-Yu Qu, Wei-Ming Kang, Bo He, and Guang-Fu Yang in “Palladium-Catalyzed Cross-Coupling Reactions: A Powerful Tool for the Synthesis of Agrochemicals.” Cross coupling reactions are essential for many new pharmaceuticals and agrochemicals, and to expand upon that Jennifer L. Minnick, Doaa Domyati, Rachel Ammons, and Laleh Tahsini in “C-X (X = N,0) Cross-Coupling Reactions Catalyzed by Copper-Pincer Bis(N-Heterocyclic Carbene) Complexes” have shown that certain copper catalytic complexes can replace Palladium in these cross coupling reactions. These copper catalytic complexes have the stark advantage of being cost effective, which contrasts palladium since it is very expensive. The number of these copper catalytic complexes is limited, and there are many more ligand copper combinations that have yet to be discovered or tested to see what effects and capabilities they have in the overall scheme of potentially replacing the need for palladium allowing for cost effect cross-coupling reactions.

 

B-33       Abigail Page

Research Collaborators:  Dewan Russel Rahman 

Research Presentation Title:  Route to Novel Non-Toxic Inorganic Pigments

Faculty Research Mentor:  Allen Apblett, Chemistry

 

Many organic pigments in current use are toxic or can fade in sunlight so their replacement with non-toxic, stable, inorganic compounds is desirable. During an investigation of a novel green extraction of metal from ores it was discovered that, when ores containing amorphous silica were exposed to metal hydroxides dissolved in ammonium hydroxide, brightly colored solids were formed. To capitalize on this discovery, silica gel was soaked in various aqueous metal amine hydroxide complexes to produce pigments whose color depended on the metal used: cobalt (purple), copper (blue), and nickel (green). The reactions presumably form metal silicate hydroxide minerals leading to the intense colors. The products were analyzed by several instrumental methods including thermal analysis that revealed that heating can be used to transform the pigments to new colors.  For example, there was a color change in the cobalt product from purple to blue, when pyrolyzed at high temperature. Purple and blue inorganic pigments have been prized since ancient times (e.g. Egyptian blue, CaCuSi4O10, used by the pharaohs) and the development of a low temperature green process for inorganic pigments has exceptional promise for meeting the needs for the world for stable non-toxic pigments.

 

B-34       Bailey Robertson

Research Collaborators:  Spencer Pitre, Tarannum Tasnim

Research Presentation Title:  Hydroquinones as Halogen-Bonding Catalyst for Activating Alkyl Halides

Faculty Research Mentor:  Spencer Pitre, Chemistry

 

The purpose of this study is to develop a better understanding of how hydroquinones serve to catalytically activate alkyl halides through halogen-bonding interaction to form visible-light absorbing charge-transfer complexes (CTC). A CTC, also known as an electron donor-acceptor complex (EDA), is the generation of a new ground state aggregate by the association of an electron-rich substrate, also known as a donor, along with an electron-poor substrate, which is known as an acceptor. The CTC is often able to absorb in the visible light region, whereas the individual substrates are not, providing an alternative strategy for performing visible-light mediated reactions. Prior work from our lab found that substituted hydroquinones effectively catalyze radical perfluroalkylation reactions by using perfluoroalkyl halides as radical precursors. In this work, we focus on expanding these reactions to silyl enol ethers to generate a-perfluoroalkyl ketones.

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