FACULTY RESEARCH INTERESTS
Analytical Characterization of Bourbon
The Demoranville group investigates the chemical components of bourbon using chromatographic methods. Currently we are developing methods to accomplish that goal and long term hope to study the impact of different production processes using those methods.
Technical Art Historical Analysis of Paintings and the Scientific Analysis of Artists’ Materials
Dr. Jeff Fieberg’s current research interests are in technical art historical investigations of modernist paintings and analysis of artists’ materials. In 2011-2012, he participated as the first Sabbatical Leave Research Fellow in Technical Art History at the Indianapolis Museum of Art (IMA). Working in the Conservation Science Laboratory directed by Dr. Greg Smith ’95, technical analyses of paintings from the IMA’s European collection were performed using x-ray fluorescence spectroscopy, Raman microspectroscopy, and infrared microspectroscopy. Artwork analyzed included Mysterious Departure by Giorgio de Chirico and the Cincinnati Art Museum’s Undergrowth with Two Figures by Vincent van Gogh. In Van Gogh’s Undergrowth with Two Figures, a pink geranium lake pigment had photochemically faded to white. Analysis of 387 white flowers in the painting revealed that 37.7 % of the white flowers were originally pink. A digital reconstruction of the painting was made to suggest the painting’s original appearance with regard to the faded flowers. This study on Undergrowth with Two Figures was published in 2017 in Applied Spectroscopy and may be downloaded here. Fieberg is currently on sabbatical (spring 2019) at the IMA (Newfields) where he will continue to analyze artwork—primarily paintings from their Modern European Collection.
Fieberg transforms the technical art analyses of paintings into pedagogical materials used in his Molecular Modernism course. For example, Fieberg designed a dry laboratory in which students investigate whether de Chirico’s painting, Mysterious Departure, is authentic, a forgery, or a verifalsi (painted by the artist but backdated). This student activity was presented as a poster at the International Council of Museums-Committee on Conservation Triennial Meeting in Copenhagen, Denmark, in 2017 (you can view the poster here). Fieberg has taught Molecular Modernism as a three-week travel course in Paris and Provence (France), a semester-long course in Strasbourg (France) and London (England), and a first-year studies course on campus with field trips to Indianapolis, Chicago, and/or Washington D.C.
On campus, Fieberg and his students have collaborated with religion professors, Dr. Beth Glazier and Dr. Tom McCollough, to work with ancient lead amulets to date, electrolytically reduce, and unroll them. Current projects include a forgery investigation of an early 20th century painting and collaboration with a student to refabricate ancient glass colors.
Spectroscopy and Intermolecular Interactions
In our group we are interested in exploring the species which exist in solutions using a combination of infrared spectroscopy and computations. Solutions are held together by networks of intermolecular forces. Though these are often thought of as transient interactions, solutions with strong interactions have a tendency to order into pseudo-stable structures. With infrared spectroscopy we can probe these structures and their environments using the vibrational motions of involved functional groups. We also perform structural computations to investigate how various ordered species will impact the vibrational motion being used as a probe. Combining these two data sets gives us the ability to elucidate what these ordered species might be. Currently, our group is exploring non-lithium ion battery electrolytes, which contain magnesium or zinc ions in organic solvents. The species likely to exist in these electrolytes include solvated ions, ion pairs, or ion aggregates. Magnesium and zinc ions are particularly interesting because they can provide insight into what properties have the most influence on solvation structures. Since these two ions have identical charge and ionic radii, the differences which arise must be from their electronic configurations. We are also currently investigating the effects of salinity on hydrogen-bond interactions between water and small organic molecules. The effect of salinity on aqueous biochemical solutions is commonly called the Hoffmeister effect. However, most molecular scale studies of what happens to cause the observed trends in protein folding and unfolding have either looked from the perspective of water or that of large polymers and proteins. We are attempting to approach this puzzle from the perspective of something in between by looking at effects on intermolecular forces as probed by the vibrational motions of small organic solutes.
Biochemistry and the Investigation of Fermentation Conditions and Contamination
Ethanol is produced as a fermentation product or as a petroleum product. Approximately 90% of the ethanol produced in the United States is produced via fermentation. In 2013 over 13 billion gallons of ethanol were produced in the United States. Most of this ethanol is produced for fuel consumption (OSHA, 2015). During the process of fermentation, bacterial contamination has the potential to decrease the production of the ethanol and increase the production of organic acids that are less desirable. Microbial communities have been previously studied in biofuel ethanol production facilities (Murphree, 2014; Qing, 2015). However, the microbial communities in potable ethanol have yet to be characterized. This project will utilize samples from 3-5 potable ethanol distilleries. The samples will be characterized by microbial culture and presence of DNA.
Physical Organic Chemistry and Computational Studies for Drug Discovery
Muzyka and her students are using computational methods to identify potential inhibitors of the MurA enzyme. We have docked and scored a library of one million compounds that are available commercially. We found over one thousand compounds which have better scores than the natural ligand for this enzyme. We acquired some of these compounds for testing.
Muzyka and her students also carry out molecular dynamics calculations with these compounds on the supercomputer at the University of Kentucky. These calculations allow us to better understand how each compound examined interacts with the amino acids in the protein’s active site. We have carried out similar calculations with fosfomycin so that we can compare binding of potential inhibitors to this known inhibitor. The computational results are analyzed in parallel with the experimental results from our collaborators, hopefully providing insights into the observations.
Peptide-Based Inhibitors and Metal Chelators for Disease Treatment
Metals have important roles in infection and disease progression. My research focuses on the design and synthesis of peptide-based inhibitors and metal chelators for disease treatment. The primary project outlined below serves as the focal points of my interdisciplinary collaborative research and provides a sound basis for students to learn and apply synthetic organic chemistry to the specific fields of amino acid and peptide synthesis and metal coordination chemistry.
Phosphate (PO43-) is a small molecule that plays an important role in controlling and triggering many of the body’s main signaling pathways. Many common diseases are the result of improper regulation of the small molecule, phosphate (PO43-) including diabetes, and various forms of cancer. In order to prevent improper phosphate regulation, we can inhibit the enzymes related to phosphate binding, therefore preventing the unwanted reactions and halting disease progression. An effective inhibitor would selectively and irreversibly bind to the active site. A compound capable of providing these interactions would provide flexibility to the regulation of these enzymes. One potential phosphate mimic is vanadate, VO43-. Vanadate, an inorganic molecule, has a similar structure and size as phosphate, while also having low toxicity in the body. The goal of this project is to synthesize and screen a peptide linked vanadate complexes designed to inhibit a key enzyme in glucose processing that has been linked to diabetes, the phosphotyrosine phosphotases (PTP), PTP1B.
Anticancer Drugs, Nanoparticle Drug Delivery, and New Diagnostic Systems
Research in the Scott lab lies in the interface between chemistry, biology/biochemistry, and nanotechnology in an effort to develop improved diagnostic and therapeutic systems with implications across medicine and pharmaceutical sciences. There are several different projects students can be involved in with the major theme of generating new ways to treat and monitor cancer or other diseases.
Bacteria are used to produce new anti-cancer molecules, which will be further modified to enhance not only the potency, but also the specificity of the drugs toward cancer. These new molecules will be investigated with regard to their ability to selectively kill cancerous tissue (cytotoxicity). We are currently exploring the drugs ability to kill lung cancer cells grown in the lab. Once generated, the new anticancer agents will also have the opportunity to be incorporated into a nanoparticle drug delivery system. The delivery systems will be used to further optimize the delivery to drug to the tumor and reduce non-specific side effects.
Nanotechnology is being utilized to create a tunable drug delivery platform. Unwanted side effects are a major hurdle with current chemotherapy options. A system capable of selectively delivering a drug payload, only when the nanoparticle has accumulated in a tumor, will greatly improve the perspective for new and old anticancer drugs alike. To that end, biomolecules will be combined with inorganic and polymeric materials to create a tunable “theranostic” nanoparticle that will not only deliver multiple drugs at specified intervals but also be used to monitor disease state and therapeutic response. Theranostic is a hybrid word, describing a particle that can combine therapy and diagnostic capabilities in a single entity.
Sensors are also being developed using gold and iron oxide nanoparticles. The sensors will be capable of monitoring different targets, such as DNA, proteins, or small molecules. Of particular interest is the development of a device that would capable of real-time feedback, with applications in analysis situations such as third world countries, operating rooms, and athletic sidelines.
Students will have the option to gain experience with a range of chemical and biochemical techniques including cell and tissue culture, natural product production and isolation, in vitro cytotoxicity assays, molecular biology, sensor development, and nanoparticle synthesis, optimization, and characterization. Students will be prepared for life after Centre whether that includes professional school (medical, pharmacy, etc.), graduate school, or the workforce.
Ruthenium and Spectroscopy for DNA Sensing
Ruthenium polypyridyl complexes have many different properties that can be exploited. The ligands that bind to the ruthenium can be easily modified, the complexes absorb visible light, can be luminescent, and can bind DNA in different ways. I am specifically interested in studying the spectroscopic properties of ruthenium polypyridyl complexes as the environment around them changes, specifically when in the presence of DNA.
Novel Multimetallic Complexes and Climate Effects on Volcanic Erruptions
The synthesis of multimetallic complexes with unusual geometry, electronic and magnetic properties
My collaborative research with students focuses on synthesizing novel multimetallic complexes of polyanionic chelating ligands. These ligands stabilize transition metals in high oxidation states and unusual geometries. For instance, the cobalt ions below are in an uncommon square planar 3+ oxidation state. The Co(III) ions are also paramagnetic. The oxidation/reduction behavior of these compounds is fascinating. I have shown in previous research that these metal complexes can themselves act as ligands for other transition metals. This research introduces the possibility of using them to construct new materials with interesting electronic and magnetic properties. My student collaborators and I are in the process of synthesizing and characterizing a wide range of multimetallic complexes of different polyanionic chelating ligands.
Stable Isotope Geochemistry of Volcanic Supereruptions
I also have a collaborative research project with geologists at the University of Oregon studying the climate effects of ancient volcanic supereruptions. We study eruption products in the John Day Fossil Beds in eastern Oregon by oxygen isotope geochemistry. Very large silicic eruptions, called supereruptions, can inject massive quantities of sulfur dioxide, SO2, into the atmosphere. The SO2 is then oxidized by either hydrogen peroxide or ozone to produce sulfur trioxide, SO3. The sulfur trioxide will combine with water to form sulfuric acid, H2SO4, which will form very small droplets called an aerosol. The aerosol will block solar radiation and lead to local or global cooling. Over time, the sulfuric acid falls back to earth as acid rain. It is impossible to directly measure SO2emissions for ancient eruptions, but the sulfuric acid content can be measured in the rock record. We use a laser fluorination line to separate oxygen from the sulfur and then a mass spectrometer to measure the 17O:16O ratio. If the SO2 was injected into the stratosphere, the major oxidant would have been ozone and the 17O:16O ratio would be higher than normal. If the SO2was injected into the troposphere, the major oxidant would have been hydrogen peroxide and the 17O:16O ratio would be normal.
Bioinspired Lignin Oxidation with Manganese, Iron, and Cobalt Catalysts
Lignin is a biological polymer that gives wood its rigid structure and fuel value. Lignin also contributes to the brown color of unbleached Kraft paper, the flavor of bourbon, and the vanilla smell of old books. However, from a chemist’s perspective, lignin is a vastly underutilized source of carbon atoms, which could use used to make biofuels, commodity chemicals, or pharmaceuticals. The reasons for the underuse of lignin are twofold: first, lignin has a complex, irregular structure that resists the chemist’s attempt to order it into smaller units and second, the chemical bonds in lignin are strong and stable and thus difficult to rearrange into more valuable products.
In nature, white-rot fungi selectively degrade lignin but not cellulose by producing enzymes that use metals such as iron and manganese to activate hydrogen peroxide as a relatively benign oxidizing agent. Inspired by the ingenuity of the white-rot fungi, my students and I are studying a family of iron, manganese, and cobalt complexes as catalysts for lignin oxidation. These complexes speed up the reaction between lignin-like molecules and oxidizing agents such as Oxone or hydrogen peroxide.
We use instruments like high performance–liquid chromatography (HPLC), gas chromatography–mass spectrometry (GC-MS), and nuclear magnetic resonance spectroscopy (NMR) to probe the secrets of these catalysts in order to understand how they work and how to improve them. Students who join my group gain may experience in instrumental analysis, kinetics, and chemical synthesis. While the Young Group is happy to consider students at all levels, students are usually more productive after they have taken CHE 241: Organic Chemistry I.
PRESTON MILES (EMERITUS)
Trace and Ultratrace Determinations in Environmental Matrices
Preston Miles held the John H. Walkup Professorship of Chemistry from 1997 until his retirement in 2019, and has served as chair of the natural science program.
Miles is an analytical chemist who worked in research and development in private industry before joining the Centre faculty. He is deeply committed to getting Centre students involved in collaborative research. His research has focused on the development and application of methods for trace level analyses. Recent projects include the determination of toxic heavy metals in woody plant materials, the determination of cortisol in urine and feces from both captive and wild wooly monkey populations, and most recently, the determination of PPCP’s in surface waters.
His dedication to sustainability led him to play a significant role in making Centre a more environmentally conscious place. He led the President’s Climate Commitment Advisory Committee from its inception, fostered the partnership with a local low-impact hydroelectric station, and was instrumental in the installation of solar panels on campus. Miles also developed Centre’s Climate Action Plan which commits the college to significant reductions in carbon emissions.
Miles developed a number of successful grant proposals on behalf of the sciences at Centre. He holds a B.A. from Centre and earned a Ph.D. in analytical chemistry from the University of Kentucky.