Dr. Stephen Tajc

The Marcellus Shale has been known to contain usable natural gas for over 75 years, however previous drilling methods were not adequate for releasing the trapped natural gas from the shale.  The development of horizontal fracture drilling (hydraulic fracturing) and slick-water fracturing fluids now makes drilling these difficult areas a reality. Hydraulic fracturing uses a large volume of slick-water that is composed of freshwater, sand, and chemical additives.  A volume of 7-15 million gallons of water may be required to produce a sufficient horizontal fracture in a single natural gas well.  Flowback wastewater is collected, and much of this water is contaminated with halogens and metals, which are classified as total dissolved solids (TDS).  There are reports that hydraulic fracturing drilling produces flowback water exceeding 200,000 mg/L of TDS.  The United States Environmental Protection Agency considers any amount over 500 mg/L of TDS for drinking water to be contaminated.

Water treatment has been an important and often overlooked component of the hydraulic fracturing process.  Currently, the primary method of hydraulic fracturing flowback water disposal is deep underground injection into caverns using EPA Class II disposal methods.  There is a urgent need for new hydraulic fracturing flowback water purification methods to combat the increasing demand for natural gas drilling in shale.  Affordable and environmentally friendly methods should be a high priority as to preserve our drinking water and fragile ecosystem. My research group explores the structure activity relationships of pyridine-based small molecules that can sequester metals in water, in addition to the capabilities of the small molecules:metal complex to be used as a source of nutrition by bacterial found in soil.

Expression of recombinant intimin and translocated intimin receptor proteins in E.coli cells

Kayla Page, Christopher Redmond, Claire Sobraske, and Dr. Lynn O'Brien

Abstract: Enteropathogenic and enterohemorrhagic E.coli (EPEC and EHEC) cells that attach to human intestinal epithelium result in the formation of effacing lesions, which is the precursor of intestinal cell membrane disruption and diarrhea in infected individuals. Two proteins, intimin and the translocated intimin receptor (TIR), play an essential role in attachment to intestinal epithelial cells.

E. coli first expresses TIR, which is translocated to the host cell via a type‐III secretion system. TIR then becomes immobilized in the intestinal epithelium with its intimin binding domain exposed on the intestinal cell surface. Intimin, from the E.coli surface, then binds TIR and attaches the E. coli cell to the intestinal epithelium, which leads to lesion formation. These types of infections can take up to 24 hours to diagnose and there has not yet been a small molecule developed to speed up this diagnostic process, prevent further infection, or allow sooner initiation of treatment. The initial expression of recombinant TIR and Intimin proteins and their purification will be discussed.

Effect of Educational Videos in the Classroom

Emily Loiodice, Sarah Forney, and Dr. Kelly Hutchinson-Anderson

This project investigated creative methods to teach science in city schools so as to engage students and make a positive impact on their view of science. In particular, we examined the way that solar energy can be taught in the classroom using short educational videos in addition to interactive lessons. We have partnered with the team at Prove Your World in an effort to research students’ misconceptions of the topic of solar energy and find a variety of methods to overcome these conceptions and explain the topic including a short video clip with puppets. Currently the video is in the process of being scripted and filmed, and we hope to have the lessons and video out to schools in the fall of 2015.

Synthesis of small molecule receptors for binding cations

Allison O'Neil, Jacob H Murray, Jacob D Murray, Steven Lewis, and Dr. Stephen Tajc

Abstract: Heavy metal pollution has been causing problems with the purity of our fresh water supplies. A history of mining has led to heavy-metal contamination of both ground and surface water in many areas of the United States^. Small molecule receptors that bind cations in aqueous solution may have potential as a water purification technique. Dipicolinic acid (DPA) is a small molecule formed in bacteria spores and is known to chelate calcium. DPA, which has been found to aid in heat resistance for the bacteria endospores,may also have potential as a small molecule that binds larger heavy metal cations. Our research focuses on the structure activity relationship of DPA and DPA derivatives to determine the fundamental binding characteristics of DPA:cation interactions in aqueous solution.

Investigation of the effect of alcohol size on the methylation kinetics of eleic acid catalyzed by SnBr₂

Goodwell Nzou, Elana Tontarski, and Dr. Richard Hartmann

_{Abstract: Previous work in our group has shown SnX2 (X=F, Cl, Br, I) as effective catalysts with a reaction rate trend of I>Br>Cl>F. In an effort to deduce the mechanistic pathway, we have designed a series of experiments to investigate the steric effect of different alcohols. We are evaluating the effect of the steric bulk of methanol, ethanol, propanol, isopropanol, and butanol in order to understand the trend.}

1H NMR analysis of the methylation of acetic acid catalyzed by tin (II) bromide:  A kinetic study.

Nandini Singh, Nicole Bayona, Jaissy Sekhon, and Dr. Richard Hartmann

Abstract: Biodiesel made from waste cooking oil is a popular substitute for petroleum diesel. However, due to its high content of free fatty acids (FFA), waste oil must undergo an initial acid catalyzed esterification. This process typically employs concentrated H2SO4 but we chose a milder Lewis acid, tin (II) bromide, as our catalyst. Our investigation is part of a larger project which employs acetic acid, and tin II bromide as catalyst at various temperatures to verify computational derived activation energy and mechanistic data acquired from a collaborator. The preliminary data suggest the formation of a methanol-tin complex as the acidic species in this reaction. This poster will present our interpretation of the data and discussion of the mechanistic pathway it supports.

Dipicolonic acid with metal cations as a nutrient source for soil microorganisms

Cara R Czechowki, Sarah Getsy, and Dr. Stephen Tajc

Abstract:Water contamination of heavy metals from hydraulic fracturing is an increasing threat to environmental and human safety, and an effort to find ways to remediate these waste waters is necessary. It has been suggested that the compound dipicolinic acid (DPA) that is naturally produced by Bacillus subtilis spores is able to chelate to metal cations, specifically Ca2+. In this research we explore the possibility of other soil microorganisms such as Bacillus licheniformis to utilize Ca2+-DPA as a nutrient source. The metabolism of metal ions with DPA by soil bacteria will then allow further insight into the bioremediation of waste waters polluted by heavy metals.

Study of small molecules and their chelating capabilities in an aqueous solution

Hannah E Garlick, Nicole R Delello, Stacy Yazo, and Dr. Stephen Tajc

Abstract: It is known that some small molecules naturally chelate to cations in water. One small molecule of interest is Dipicolinic acid (DPA). DPA is found naturally in certain species of bacterial spores and is well-known that DPA chelates calcium ions. Further research is being done to observe chelation to larger cations with DPA and synthetic derivatives of DPA. Using UV-VIS titrations, DPA's chelating ability was studied with other heavy metals. The binding capabilities of DPA to magnesium, silver, strontium, cobalt and iron in aqueous solution have been measured. In addition, the stoichiometry of DPA has been measured with larger cations via Job's plot.

Synthesizing DPA derivatives to identify effective cation scavengers

Nick Polito and Dave Studin

Abstract: Dipicolinic acid (pyridine-2,6-dicarboxylic acid)(DPA) is a pyridine-based compound produced by gram-positive, spore producing bacteria. DPA has been shown to successfully chelate Calcium metal ions in aqueous solution.[i] DPA-derivatives may have the ability to act as heavy metal scavengers in aqueous solutions making them a novel alternative for the purification of contaminated water. My research involves synthesizing DPA-derivatives to create more feasible schemes for the production of derivatives. Several successful synthetic routes have been confirmed. The resulting derivatives were tested for their structural activity relationship for binding. Using various organic synthesis schemes to produce new compounds and UV-titration to test the binding ability of these compounds, we hope to identify DPA derivatives that will successfully scavenge metal ion contaminants in water.

[i] Lewis, J. C. (1967). Determination of dipicolinic acid in bacterial spores by ultraviolet spectrometry of the calcium chelate. Analytical biochemistry, 19(2), 327-337.

Modifying small molecule HIV-1 viral entry inhibitors to bind glycoprotein qp120 on a solid surface

Cara Czechowski with Dr. Stephen Tajc

Abstract: According to the World Health Organization, 34 million people are currently living with HIV. Small molecule HIV viral entry inhibitor drugs are interesting compounds as they target protein complexes involved in viral membrane fusion that could be used for HIV diagnostics. The small molecule drug BMS-806 binds to the HIV-1 envelope glycoprotein gp120 and is a potent HIV-1 viral entry inhibitor. In this research we explore adding a synthetic linker using solid surface techniques to BMS-806 focusing on the portion of 7-azaindole with amine molality. The linker on BMS-806 will then allow for solid surface binding analysis with gp120. These studies will provide further insight of HIV-1 viral protein interactions with small molecules.

Towards the analysis of small molecule HIV-1 viral entry inhibitor with qp120 on a solid surface

Goodwell Nzou with Dr. Stephen Tajc

Abstract: The number of people dying from HIV/AIDS infection continues to escalate throughout the world. There is a critical need for smaller, inexpensive molecules for the diagnosis of the virus to help minimize the proliferation of this pandemic. Currently, a rapid HIV test that utilizes antibodies is available for diagnosing an HIV infection1. However, a large antibody protein is less stable and cost more to produce large quantities than a small molecule with similar binding capabilities. This project is geared towards the exploration of NBD-556, which binds to the HIV-1 envelope glycoprotein gp1202. Understanding the solid surface binding capabilities of this small molecule HIV-1 viral entry inhibitor may lead to fast and affordable diagnosing tools for lower income areas both domestic and worldwide.

Systematic modification of electron density on a series of tungsten based Lewis acid catalysts with minimal structural changes

Molly Kingsley and James Chambers with Dr. Richard Hartmann

Abstract: The results of recent experiments in our group have shown that tungsten compounds (WCl6 and WCl4(PPh3)2) are successful Lewis acid catalysts in the methylation of oleic acid. While it is clear the oxidation state of tungsten influences the rate of reaction, we are unsure of its specific role because both structural and electronic changes were made. In an attempt to investigate the sole effect of electronic changes, we have systematically synthesized a group of compounds of the general formula: WCl4(PPh3-X)2 (X = H, F, Cl, O-CH3, and CH3, all in the para position). These compounds present a scenario where no appreciable change to the structure has been made, yet the electron density of tungsten is influenced from afar. We report here the synthesis, and characterization of these compounds along with a 1H NMR study of their ability to catalyze the methylation of oleic acid.

Tin(II) halides as catalysts for the methylation of eleic acid

Elana Tontarski with Dr. Richard Hartmann

Abstract: Although biodiesel is known to be an effective and environmentally sound replacement for petroleum diesel, it has remained a marginal fuel because of high production costs. The majority of this cost could be eliminated if high free fatty acid (FFA) waste oils were employed as the starting material rather than virgin oils. Because these kinds of oils require acid catalyzed pretreatment, we have been investigating a variety of mild Lewis acids as replacements for the highly caustic and sulfur containing H2SO4 which is the standard catalyst employed. Using oleic acid as a model FFA we have found SnX2 (X = F, Cl, Br, and I) to be an effective catalyst for this reaction and have also observed an interesting trend in reaction rates (I>Br>Cl>F). This poster will present our findings along with a discussion of their significance and the unique use of 1HNMR to determine the rates of these reactions.

Investigation of the kinetic isotope effect with tin(II) bromide for the esterification of oleic acid

Nandini Singh and Nicole Bayona

Abstract: Biodiesel made from waste cooking oil is a popular substitute for petroleum diesel. However, due to its high content of free fatty acids (FFA), waste oil must undergo an initial acid catalyzed esterification. This process typically employs concentrated H2SO4 but we chose a milder Lewis acid, tin (II) bromide, as our catalyst. Our investigation is part of a larger project which uses oleic acid as a model FFA, and the tin(II) halides (SnF2, SnCl2, SnBr2, and SnI2) as catalysts.

Our investigation primarily focuses on the tin(II) halides SnCl2 and SnBr2, because previous research suggests that these two halides are most appropriate for the methylation of oleic acid. Methanol-D was substituted for methanol in order to assess the role of this species in the overall mechanism. Through the use of NMR, we have determined that methanol-D does eventually make methyl ester, but it takes substantially more time for the reaction to occur and it also occurs best at 60ᵒC. Our investigation is done at 55ᵒC and 60ᵒC with both the SnCl2 and SnBr2 halides compare the percent methyl ester created from the different temperature of the two different tin(II) halides. This poster will present our interpretation of the data, how it relates to potential mechanisms, involved in determining the rate limiting steps and the broader impact for the series of tin(II) halides.

Activation energy determination for the esterification of free fatty acids in oleic acid for biodiesel synthesis using Lewis acid tin (II) iodide

Kristin Nichols with Dr. Richard Hartmann

Abstract: Biodiesel is a readily produced and commonly used alternative fuel source. Biodiesel can be synthesized from renewable resources, such as used cooking oil, through esterification of free fatty acids (FFA) or transesterification of triglycerides. Because used oils are often contaminated with FFA's we have chosen oleic acid as a model system for investigating reactions that convert FFA into methyl esters. An acid catalyst is used to treat the FFA's and create fatty acid methyl esters (FAME). Tin halides are common Lewis acid catalysts and are readily available. Preliminary results show that the rate constants for these reactions fit the following trend: SnF2 < SnCl2 < SnBr2 < SnI2, monitoring the reaction progress using 1H NMR. Based on these results, we have undertaken a series of experiments to determine the activation energies of the reactions. This poster will present my methods and results on the use of tin (II) iodide to catalyze the methylation of oleic acid.

Synthesis of tin (II) halide-phosphine complexes and characterization via ^119, Sn, ³¹P, and ¹⁹F NMR spectroscopy

Briana Laubacker with Dr. Richard Hartmann

Abstract: Recent work in our labs has shown SnX2 (X = F, Cl, Br, and I) to be effective Lewis acid catalysts for the methylation of oleic acid. The results show a clear trend in reaction rates, with SnI2 being the best catalyst and SnF2 the worst. However, we are unable to determine if this result is due to changes in electron density at the metal center, or the steric bulk introduced by the halide ligands. In an effort to systematically modulate the electron density on the tin center we have undertaken the synthesis of several phosphine derivatives of each tin (II) halide using the following phosphines: triphenylphosphine, tris(4-chlorophenyl)phosphine, tris(4-fluorophenyl)phosphine, tris(4-methoxyphenyl)phosphine, tri(p-tolyl)phosphine, 1,2-bis(diphenylphosphino)ethane, and trioctylphosphine. 119Sn, 31P, and 19F NMR studies verify the formation of several novel compounds and this poster will discuss the interpretation of these spectra and the possible identity of the compounds that were formed.

Investigating the effect of steric bulk on the catalytic activity of substituted tin(II) chlorides in the esterification of a free fatty acid

Emily Benton with Dr. Richard Hartmann

Abstract: Recent work in our group has shown tin(II) halides to be effective Lewis acid catalysts for the esterification of a free fatty acid (FFA) with an unusual pattern of reaction rates (I> Br> Cl >F). To confirm that this effect is due to steric bulk, substituted tin(II) chlorides of the form SnCl2X2 (X= Me, Et, t-Butyl) were used as catalysts under the same reaction conditions as the original halides. Reaction rates for the substituted halides follow a similar trend (t-Buytl> Et > Me). We present here the methods used to obtain and analyze our data, our potential mechanisms of this reaction, and our planned future work.

Structural analysis of HIV-1 inhibitor drug candidate BMS-378806:  The role of benzyl derivatives

McKenna Murphy and Emily Triplett with Dr. Stephen Tajc

Abstract: Since the discovery of HIV in 1981, AIDS has caused the deaths of millions of people. The current treatment requires high dosages and results in unfavorable side effects that discourage long-term use. BMS-378806 is a small molecule HIV-1 inhibitor that is preferable to the current therapy. However, little is known about the mechanism of this drug. This research aims to identify the most effective functional groups by attaching structural variations to the piperzine-adjacent phenyl ketone. These structural variants may be analyzed by isothermal titration calorimetry (ITC) to determine thermodynamically favorable binding conditions. This data may be used to construct an even more effect HIV-1 inhibitor.

Development of small molecule linkers towards solid surface analysis of HIV-1 viral envelope proteins

Sarah Wazenkewitz, Jennah Wolcott, and Goodwell Nazou with Dr. Stephen Tajc

Abstract: There are millions of people that are currently infected with HIV/AIDS, yet countless contagious individuals remain unaware that they are infected. The Center for Disease Control is presently supporting a two-year study on a free HIV antibody rapid screen test for Americans to examine if increased availability and convenience will promote HIV diagnostics and awareness1. The antibody protein used in this test however, is less stable and costs more to produce large quantities than a small molecule with similar binding capabilities. Small molecule HIV viral entry inhibitors have been found to be a promising new class of drugs due to the ways in which they can target protein complexes that are involved in the process of viral membrane fusion, specifically the HIV-1 glycoprotein gp120. This research is designed to gain a fundamental understanding of small molecule HIV-1 viral entry inhibitors with synthetic linkers towards solid surface analysis of gp120.

Modifying small molecule BMS-806 to bind glycoprotein qp120 on solid surface

Moudi Hubeishy with Dr. Stephen Tajc

Abstract: HIV infection continues to be a prevalent stress in the nation. About 1.2 million people are living with HIV in the United States but approximately 240,000 are unaware of their infection. The Center for Disease Control and Prevention (CDC) is studying to rapidly screen for HIV by using antibodies.1 However, antibodies are large proteins that cost more and are less stable than small molecules, we are interested in using a small molecule drug that is proven to bind to the HIV-1 envelope glycoprotein gp120 such as that of BMS-806.2 In this research, we explore the addition of a synthetic linker to create an amine on the 7-azaindole portion of BMS-806 in solution. This amine will allow us to covalently attach a linker to BMS-806. The linker will allow for solid surface binding analysis so then we might have more information about how the HIV-1 viral protein interacts with small molecules.

Examination of dipicolinic acid scaffolds containing cis-cyclopenta-1,3-dial under aquatic conditions

Nepherteria Wright with Dr. Stephen Tajc

Abstract: Typically dipicolinic acid (DPA) is noted for its association with calcium in spores. It has also been reported to associate as a bidentate ligand with iron, copper, and cobalt. Previous studies had shown the association between derivatives of DPA scaffolds and zinc. We are exploring DPA binding potential with scaffolds during aquatic mono-association. We have begun investigation towards bridging two DPA molecule with cis-cyclopenta-1,3-dial. It has been hypothesized that the cup-shaped DPA molecule will chelate well with the cation in water.

Optimization of solubility and chelating effects of dipicolinic acid

Alan Lee Connor and Jacob Murray

Abstract: Dipicolinic acid (DPA) has been shown to have strong chelating capabilities in polar solvents with various metals. DPA lacks hydrophilicity therefore it is pertinent to modify the structure in order to maximize chelating effects. Structure activity relationships (SAR) will allow us to identify the fundamental bonding characteristics of DPA through various modifications aiding in the optimization of DPA solubility in polar solvents, in turn improving binding to metals. In this research we utilized synthetic chemistry to modify DPA for SAR studies in aqueous solutions.

Investigation of dipicolinic acid-derivatives using structural activity relationships

James Chambers with Dr. Stephen Tajc

Abstract: Some bacteria spores release dipicolinic acid (DPA) is a naturally occurring compound released that is known to chelate to calcium, copper, cobalt and iron. DPA has multiple parts on the molecule that could be used for chelation, and although the location of the interaction has been extensively studied the binding could be optimized. Testing DPA and its derivatives with other cations will help to determine the optimal binding for cations and the essential aspects for optimization. Performing a structural activity relationship test on the DPA molecule will allow us to find compounds with better chelation as well as allow us to further understand the mechanism of binding allowing us to improve the binding capabilities.

Universidad De Concepcion, Chile
Andrew Cross (BCH '18) and Shane Fuentes (BCH '18)

Shane Fuentes researching nano-particle polymers in Dr. Urbano's laboratory.

Shane Fuentes, Andrew Cross, and Eduardo (the head of the Chemistry department at Universidad de Concepcion) in the lobby of their science building. 

University of Rochester - Rochester, NY
Kathryn Proe
Biological electron donor project. The group is working to get deeper into bioelctrochemistry and microbiology as they work to identify a sustainable supply of electrons for photochemically driving hydrogen evolution from water.

Mentor:  Dr. Sanela Lampa-Pastrik

University of Rochester - Rochester, NY
Kevin Denny
Making CdSe nanoplatelets.

Mentor:  Dr. Todd D. Krauss

Penn State University - University Park, PA
Jacob Murrary - Research Experience for Undergraduates (REU) program working on efficient catalysis in modern synthesis.

University of Rochester Medical Center - Rochester, NY
Department of Biochemistry and Biophysics, Department of Dermatology

Mentor: Dr. Benjamin L. Miller

Tom Dwyer - Examining the Binding Potential of RAGE Inhibitors: Towards New Anti-Alzheimer's Therapeutics

University of California, San Diego - La Jolla, CA
UCSD Skaggs School of Pharmacy & Pharmaceutical Sciences
The Handel Laboratory

Goodwell Nzou - Optimization of Chemokine Receptor Expression in Spodoptera frugiperda 9 Cells.

University of Rochester Medical Center - Rochester, NY
Department of Chemistry, Department of Biochemistry and Biophysics, and Department of Dermatology

Mentor: Dr. Benjamin L. Miller

Moudi Hubeishy - Enhancing the Bioavailability of RAGE Inhibitors: Towards New Anti-Alzheimer's Therapeutic

Abstract: In the past ten years there has been a 68 percent increase of people dying with Alzheimer's disease (AD). AD is a neurodegenerative disease characterized by the progressive loss of brain function. The causative agent of AD is the amyloid- (A) peptide, which has been directly linked to increased levels of apoptosis in neurons. The receptor for advanced glycation end products (RAGE) has been shown to be up regulated in Alzheimer's disease to transport A peptide into the blood brain barrier. Previous research has defined a pharmacophore and designed a lead molecule, which inhibits RAGE from transporting A into the brain. In this research we set out to optimize the bioavailability of the lead compound by enhancing its hydrophilic properties by adding multiple hydrogen bonding groups. I synthesized three different analogs of the lead compound and was able to then characterize and test binding affinities for two of the analogs.

University of South Dakota - Vermillion, SD

Briana Laubacker - Modification of surface ligands coordinated to β-NaYF4: Yb, Er/Tm nanocrystals for use in security printing applications

Faculty Advisor: Dr. Stanley May

University of South Dakota - Vermillion, SD

James Chambers - Investigation into the reactivity of anilinomagnesium halides with carboxylic esters using the Bodroux reaction.

Faculty Advisor: Dr. David Hawkinson

SUNY Upstate Medical University - Syracuse, NY

Molly Kingsley - Characterization of Domain-Swapping Proteins for Design of Self-Assembling Hydrogels

Dr. Loh's biochemistry laboratory

Applying to SUNY Upstate Summer Research Program

Abstract: Molly's work focused on characterizing (and first purifying) six new protein constructs made from ribose binding protein (RBP) and ubiquitin (Ub) which both provided the lever and assembler domain. These proteins were designed to domain swap and ultimately form protein oligomers and hydrogels through the unique forced unfolding mechanism. To domain swap, the lever domain unfolds the assembler domain when it is inserted into a surface loop and the assembler domain swaps with a neighboring assembler.

She characterized the six constructs based on their solubility, stability, ability to bind ribose, and oligomerization. For use in a hydrogel, which is the ultimate goal, the constructs must be extremely soluble and have high oligomerization. Five of the six constructs were highly soluble, stable, could still bind ribose and domain swapped; two of these are moving forward to be used to make hydrogels. Protein based hydrogels have a huge potential in many biomedical uses such as tissue engineering and drug delivery.

Highland Hospital - Hospital Elder Life Program (HELP)
Rochester, NY


Alexis Bell (Biochemistry, '18)

Sophia Qureshi, Bichemistry '19


Roberto Jaquez, Biochemistry '19 (pictured with Naz student Ahmad Jackson)


The Hospital Elder Life Program is part of an innovative and comprehensive health care service for older adults. This program brings together hospital staff and volunteers to provide regular assessment, supportive visits and recreation and exercise opportunities for seniors at risk of delirium and other cognitive or physical difficulties.