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  • Undergraduate Poster Abstracts
  • Chemistry (Except Biochemistry)

    FRI-514 DETERMINATION OF THE IONIZATION CONSTANT OF CARBOXYLIC ACIDS USING MICROSCALE FREEZING POINT DEPRESSION MEASUREMENTS

    • Udya Dewanamuni ;
    • Paris Svoronos ;

    FRI-514

    DETERMINATION OF THE IONIZATION CONSTANT OF CARBOXYLIC ACIDS USING MICROSCALE FREEZING POINT DEPRESSION MEASUREMENTS

    Udya Dewanamuni, Paris Svoronos.

    Queensborough Community College, Bayside, NY.

    Freezing point depression is a colligative property that is related only to the number of particles in solution but not to the nature of the solute. For the first time, the ionization constant of a carboxylic acid (Ka = 10-1 – 10-2) is determined in a nontraditional titrimetric method. The values obtained are also the first ones ever recorded at 0 °C. The project uses freezing point depression measurements to calculate this physical property using the Van’t Hoff factor. The investigation involves the study of 5 different carboxylic acids: maleic, malonic, oxalic, chloroacetic, and dichloroacetic acids. The ionized fraction of the solute is measured through a derived equation that correlates the freezing point depression temperature. The measured Ka values of various carboxylic acids were determined at various aqueous concentrations: 1.00 M, 0.50 M, 0.25 M, and 0.10 M. The experiment is fast, uses extremely low concentrations of the solute, and the results are easily reproducible.

    THU-527 SYNTHESIS OF 2-SUBSTITUTED ESTERS OF ASCORBIC ACID USING 5,6-O-ISOPROPYLIDENE-L-ASCORBIC ACID

    • Sonjiala Hotchkiss ;
    • Samantha Barrera ;
    • Fernando De La Torre ;
    • Jose Rizo ;
    • Naquiba Williams ;
    • Adam Abdi ;
    • Akinyemi Olowu ;
    • Alberto Palacios ;
    • Edward Alexander ;
    • Emmanuel Gutierrez ;

    THU-527

    SYNTHESIS OF 2-SUBSTITUTED ESTERS OF ASCORBIC ACID USING 5,6-O-ISOPROPYLIDENE-L-ASCORBIC ACID

    Sonjiala Hotchkiss, Samantha Barrera, Fernando De La Torre, Jose Rizo, Naquiba Williams, Adam Abdi, Akinyemi Olowu, Alberto Palacios, Edward Alexander, Emmanuel Gutierrez.

    San Diego Mesa College, San Diego, CA.

    Ascorbic acid (AA) or vitamin C is a powerful antioxidant important to the healthy functioning of many plants and animals. In addition, AA is effective at suppressing growth of cancerous tumors due to its ability to inhibit the glycolytic enzymes phosphofructokinase -1 (PFK-1) and lactate dehydrogenase (LDH). Further research has shown that 6-substituted and 2,6-disubstituted fatty acid derivatives of AA inhibit PFK-1 and LDH at a greater rate than AA. Preparation of the 2-monosubstituted derivatives of AA is of special interest because it will elucidate whether its antioxidant activity affects inhibition of PFK-1 and LDH. Research has shown that 2-substituted derivatives have significantly less antioxidant activity than either 6-substituted esters or 2,6-disubstituted esters of AA, and may have mild proxidant activity. Our hypothesis was that the use of the 5,6-O-isopropylidene-L-ascorbic (IAA) method to produce AA-2-palmitate could be generalized to produce other 2-substituted monoesters of AA. This method included the synthesis of IAA using ascorbic acid, acetone, and acetyl chloride. IAA was then stirred at room temperature with a fatty acid acyl chloride in dry pyridine and dry acetone. After workup, the 2-substituted esters were recrystallized from a mixture of petroleum ether and chloroform. This method was used to synthesize ascorbic acid-2-palmitate, -2-laurate, and -2-caprylate. Thin layer chromatography, infrared spectroscopy, and nuclear magnetic resonance were used to confirm the production of the 2-monoesters of AA. A mechanism involving a carbanion intermediate is proposed for the formation of the 2-substituted esters of AA.

    THU-509 SUPRAMOLECULAR SOLAR CELLS VIA CRYSTAL ENGINEERING OF FULLERENES

    • Matthew Mena ;
    • Juan Noveron ;

    THU-509

    SUPRAMOLECULAR SOLAR CELLS VIA CRYSTAL ENGINEERING OF FULLERENES

    Matthew Mena, Juan Noveron.

    The University of Texas at El Paso, El Paso, TX.

    Fullerene and its derivatives exhibit extraordinary electrical properties suitable for photovoltaic applications and are expected to lead to next-generation plastic solar cells. Key to their development as photovoltaic materials is the ability to organize them into supramolecular structures beyond the molecule that orchestrates the conversion of light into electrical potential and electricity. Dynamic crystals are solids with structures capable of undergoing crystal-to-crystal transformations in which the crystalline phase acts as a solvent in innovated solid-solutions suitable for a wide variety of applications in environmental sustainability. We synthesized and characterized a set of closely related amphiphillic molecules based on 1-alkyl pyridinum bromide salts and studied their single-crystal-to-single-crystal transformation properties in which the bromide ion exchanges with exogenous anions such as oxoions as well as anionic fullerenes that exhibit photovoltaic properties. X-ray powder diffraction, inductive coupled plasma (ICP), NMR analysis, and UV-vis spectroscopy were used to study the crystal dynamic behavior of the materials and will be presented. Phenyl-C61-butyric acid methyl ester and its properties will be applied via pi pi stacking and ionic bonding from the negatively charged PCBA and the positively charged alkylated chain.

    THU-513 ELECTROCHEMICAL PRODUCTION OF CADMIUM CHALCOGENIDE NANOROD SOLAR ARRAYS

    • Rachel Alvelais ;
    • Martin Moskovits ;
    • Will Elliott ;

    THU-513

    ELECTROCHEMICAL PRODUCTION OF CADMIUM CHALCOGENIDE NANOROD SOLAR ARRAYS

    Rachel Alvelais, Martin Moskovits, Will Elliott.

    University of California, Santa Barbara, Santa Barbara, CA.

    The silicon solar cells used in most commercial energy production fail to convert a broad range of the solar spectrum to usable electricity. Solar cells manufactured from materials with higher-efficiencies than silicon, such as cadmium sulfide, selenide, and telluride, require painstaking and costly techniques to avoid shorted cells. The high price-to-performance ratio of these devices precludes them from industrial and commercial use. An electrochemical method of creating nanorod arrays of such high-efficiency, nonsilicon materials will make them a cost-efficient, viable source of commercial solar energy. The great number of nanorods produced in electrochemical bath processes allows for a less painstaking production method, as defects in single nanorods have little consequence on the power output of a sheet as a whole. Such electrochemical methods can be scaled to industrial levels with ease. As a proof of concept, we have electrodeposited cadmium chalcogenide/gold Schottky-junction solar cells in porous aluminum oxide, a well-established template for the growth of nanostructures such as semiconducting nanowires.

    FRI-513 EXPLORATION OF THE ELECTRONIC STRUCTURES OF NITROGEN-RADICAL PRECURSORS FOR USE IN AMINATION

    • Susana Calderon ;
    • Erik Menke ;
    • Ryan Baxter ;
    • Hrant Hratchian ;

    FRI-513

    EXPLORATION OF THE ELECTRONIC STRUCTURES OF NITROGEN-RADICAL PRECURSORS FOR USE IN AMINATION

    Susana Calderon, Erik Menke, Ryan Baxter, Hrant Hratchian.

    University of California, Merced, Merced, CA.

    Selective amination refers to the introduction of amine groups into organic systems, which is a highly versatile yet challenging synthetic practice common in pharmaceutical synthesis. As such, it is important to find new economical and efficient methods for amination. Synthetic approaches based on nitrogen-radical chemistry is a route our team is currently pursuing to address this critical challenge. To make significant progress requires an understanding of how and where nitrogen-radical precursors will be generated by nitrogen-oxygen-bond cleavage. This presentation focuses on our recent development of a protocol for predicting nitrogen-oxygen cleavage using computational chemistry. More specifically, this approach takes into account electronic and geometric changes the precursors undergo when neutral species are reduced to form radical anions. Using the B3LYP method with a 6-311+G(d) basis set, optimal structures of neutral compounds and corresponding anion states are determined and molecular orbitals are visualized to establish the presence or absence of antibonding character in the anion compounds. Our results indicate that our current computational protocol successfully predicts bond cleavage patterns and is being used to guide synthetic chemistry.

    FRI-500 WET-SPINNING OF HIGHLY CONDUCTIVE AND MECHANICALLY ROBUST GRAPHITE OXIDE FIBERS

    • Winn Huynh ;
    • Jee Youn Hwang ;
    • Jaime Torres ;
    • Richard Kaner ;

    FRI-500

    WET-SPINNING OF HIGHLY CONDUCTIVE AND MECHANICALLY ROBUST GRAPHITE OXIDE FIBERS

    Winn Huynh, Jee Youn Hwang, Jaime Torres, Richard Kaner.

    University of California, Los Angeles, Los Angeles, CA.

    Graphene’s extraordinary electronic, thermal, and mechanical properties have generated interest in engineering and materials science because of its potential applications in devices such as nanoelectronics and biosensors. However, challenges remain in translating the microscale properties of graphene to the macroscale, including but not limited to large-scale synthesis and fabrication. We have discovered that liquid crystalline dispersions of graphite oxide can be wet-spun into fibers and reduced into graphene either by chemical reduction or laser scribing. Because of this, graphene is convertable into functional materials such as batteries and other electronics, allowing its favorable properties to find their way into everyday devices. In this study, we determine whether graphite oxide can be used as a surfactant to aid in the dispersion and subsequent wet-spinning of graphene composites. We have synthesized various composite materials of graphite oxide with carbon nanotubes (CNTs) and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT-PSS), a conducting polymer. We will soon measure their conductivity and mechanical properties to determine if graphene composites can outperform graphene alone in all metrics. These composites will provide the framework for next-generation fibers for the microelectronics and aerospace industries.

    FRI-526 DETERMINING THE LINKAGE OF GENETIC AND AUTOIMMUNE FACTORS IN INTERSTITIAL LUNG DISEASE

    • Erica Poe ;
    • Mary Beth Scholand ;

    FRI-526

    DETERMINING THE LINKAGE OF GENETIC AND AUTOIMMUNE FACTORS IN INTERSTITIAL LUNG DISEASE

    Erica Poe, Mary Beth Scholand.

    The University of Utah, Salt Lake City, UT.

    Interstitial lung disease (ILD) describes a type of pulmonary illness that affects the tissue in the lower part of the lungs and can lead to scarring. There are several causes of this disease but they can be condensed into 4 main categories: environmental, autoimmune, genetic, and idiopathic. This project specifically focuses on the autoimmune and genetic aspects and how these may be associated with one another. The overall goal is simply to improve our understanding of ILD etiology as there is not a significant amount of information on this topic. Our researchers believe there is a link between patients with the disease caused by autoimmune disorders and heredity. To determine this, a clinical study is taking place. A patient must be diagnosed with ILD and have blood samples taken. Autoimmune serology is conducted from the sample to test for a disorder that may contribute to the illness. This, along with patient demographics and family history, is entered into the RedCAP database where it is currently being queried and cross-referenced with pedigrees for each patient. Results were minimal due to time constraints, but we were able to locate a pedigree that contained a familial link to the disease with 2 siblings having autoimmune disorders. This supports our proposed hypothesis. Although the work is ongoing, we expect to find more linkages between affected patients and relatives that have ILD as well as a trend with those diagnosed with an autoimmune disease.

    THU-514 SINGLE ATOM CATALYSTS FOR SOLAR FUEL PRODUCTION

    • Priscilla Torres ;
    • Andrew Peterson ;

    THU-514

    SINGLE ATOM CATALYSTS FOR SOLAR FUEL PRODUCTION

    Priscilla Torres, Andrew Peterson.

    Brown University, Providence, RI.

    Past studies have shown successful carbon dioxide (CO2) reduction and hydrogen evolution reactions (HER) with various bulk metal foils. Our research explored possible cost-effective and efficient catalysts to reduce CO2 or evolve H2 in the form of novel single-atom catalysts consisting of individual metal atoms supported on a reduced graphene oxide (rGO) substrate. We have performed galvanostatic experiments to measure the quantitative products formed by gas chromatography (GC) and infrared spectroscopy (IR) analysis. Additionally, rotating disk analysis was used as a support system to measure current activity. Three metal samples, molybdenum, copper, and silver, were annealed onto rGO at 2 distinct temperatures. Silver annealed at a lower temperature was shown to be more effective in CO2 and H2 production at lower potentials compared to the other metal samples at the same current density. A small, yet significant, amount of CH4 and C2H4 was found in certain copper samples as well.

    FRI-527 STUDIES ON THE SYNTHESIS OF 2,6-DISUBSTITUTED FATTY ACID ESTERS OF ASCORBIC ACID: ESTERIFICATION VIA ACYL CHLORIDES IN DIMETHYLFORMAMIDE

    • Fernando De La Torre ;
    • Edward Alexander ;
    • Jose Rizo ;
    • Sonjiala Hotchkiss ;
    • Samantha Barrera ;
    • Adam Abdi ;
    • Naquiba Williams ;
    • Akinyemi Olowu ;
    • Emmanuel Gutierrez ;
    • Alberto Palacios ;

    FRI-527

    STUDIES ON THE SYNTHESIS OF 2,6-DISUBSTITUTED FATTY ACID ESTERS OF ASCORBIC ACID: ESTERIFICATION VIA ACYL CHLORIDES IN DIMETHYLFORMAMIDE

    Fernando De La Torre, Edward Alexander, Jose Rizo, Sonjiala Hotchkiss, Samantha Barrera, Adam Abdi, Naquiba Williams, Akinyemi Olowu, Emmanuel Gutierrez, Alberto Palacios.

    San Diego Mesa College, San Diego, CA.

    Although widely appreciated for its antioxidant properties, ascorbic acid (AA) has also gained recognition as an allosteric inhibitor of the glycolytic enzymes phosphofructokinase-1 (rPFK-1) and lactose dehydrogenase (rLDH). Furthermore, research has implicated the mono- and di-substituted fatty acid esters of AA as potential cancer therapeutics because of their increased inhibition of rPRK-1 and rLDH. This study purposefully explores the synthesis of 2,6-disubstituted derivatives of AA using pyridine in dimethylformamide (DMF). By using this modified esterification method initially using lauroyl chloride, our hypothesis is that the major products using any acyl chloride (AC) are 2,6-disubstituted esters regardless of the molar ratio of AA to AC. A minor presence of mono-esters is also detected. A mechanism is proposed involving the formation of an intermediate carbanion on carbon 4 which leads to 6-substituted and 2,6-disubstituted esters. AA was dissolved in DMF containing pyridine followed by the slow addition of an AC. The reactions were carried out at both 1:1.5 and 1:1 molar ratios of AA to various ACs, including lauroyl and octanoyl chloride. Additionally, a parallel reaction was run using the 6-substituted derivatives and their respective ACs at a 1:1.1 molar ratio. After distilling off the DMF at reduced pressure, the residual oil was treated with another solvent capable of displacing the di-substituted products, thus isolating the compounds. The reactions were followed closely by thin layer chromatography (TLC), and spectroscopic techniques (IR/NMR). TLC confirmed that the isolated products were solely di-substituted after the procedure and the residual oil contained a mixture of the mono- and di-esters.

    FRI-512 HIDDEN POWER OF ‘UHALOA

    • Andrew Chang ;
    • Kathleen Ogata ;

    FRI-512

    HIDDEN POWER OF ‘UHALOA

    Andrew Chang, Kathleen Ogata.

    Kapiʻolani Community College, Honolulu, HI.

    ‘Uhaloa, also known as Waltheria indica, is an endemic shrub used in traditional medicine (la’au lapa’au) in Hawai‘i. As a medicinal plant, ‘Uhaloa has healing properties that help relieve the symptoms of sore throat, cough, congestion, oral thrush, and wrinkles. Due to the medicinal versatility of ‘Uhaloa, it is important to study the active compounds within the plant responsible these effects. Differential extraction with various solvents and silica gel chromatography was used to partially isolate the flavonols quercetin and (-)-epicatechin. High performance liquid chromatography (HPLC) analysis and thin layer chromatography (TLC) of partially purified extracts were used to identify and quantify the 2 flavonols in ‘Uhaloa.

    THU-521 NOVEL REDUCTION OF ARYL NITRO GROUPS ON HETEROCYCLES USING CACL2, FE, AND GLACIAL ACETIC ACID

    • Jorge Becerra ;
    • George R. Negrete ;

    THU-521

    NOVEL REDUCTION OF ARYL NITRO GROUPS ON HETEROCYCLES USING CACL2, FE, AND GLACIAL ACETIC ACID

    Jorge Becerra, George R. Negrete.

    The University of Texas at San Antonio, San Antonio, TX.

    Reductions of nitro groups on aromatic compounds are important when applied to organic molecules aimed at biological systems. These reductions are not only expensive and time consuming to produce, but require harmful materials such as lithium aluminum hydride, sodium borohydride, or palladium. To avoid using these reagents and reaction conditions, a new method was reported by Rangappa et al., for reducing the nitro group on aromatic rings using CaCl2, Fe, H2O, and ethanol. The main emphasis of our laboratory has been synthesizing novel cysteine-derived lipid analogs (CLAs) as potential antibiotics that can be armed with a peptide sequence that induces apoptosis. The heterocycle contains a thiazolidine core with an acryloyl group that can be coupled with alkyl or aryl thiols via conjugate addition and carboxylic acid and aryl nitro groups. The latter can be reduced to an amine (Pd/hydrogen) such that the carboxyl and amino groups can be employed to append a peptide chain and a fluorophore via peptide coupling methods. The aryl nitro group reduction was investigated using a CLA bearing a benzylthio ether unit. Initial reactions following the method of Rangappa showed no product formation according to 1H NMR data, but more vigorous conditions gave samples exhibiting 1H NMR signals that were shifted up-field compared to the aryl nitro group signals along with other signals expected for the desired product. The result for these studies will be presented.

    FRI-523 STUDIES ON THE SYNTHESIS OF 2-MONO AND 2,6-DISUBSTITUTED FATTY ACID ESTERS OF VITAMIN C: ESTERIFICATION USING CONCENTRATED SULFURIC ACID

    • Samantha Barrera ;
    • Sonjiala Hotchkiss ;
    • Fernando De La Torre ;
    • Edward Alexander ;
    • Emmanuel Gutierrez ;
    • Naquiba Williams ;
    • Adam Abdi ;
    • Akinyemi Olowu ;
    • Jose Rizo ;
    • Alberto Palacios ;

    FRI-523

    STUDIES ON THE SYNTHESIS OF 2-MONO AND 2,6-DISUBSTITUTED FATTY ACID ESTERS OF VITAMIN C: ESTERIFICATION USING CONCENTRATED SULFURIC ACID

    Samantha Barrera, Sonjiala Hotchkiss, Fernando De La Torre, Edward Alexander, Emmanuel Gutierrez, Naquiba Williams, Adam Abdi, Akinyemi Olowu, Jose Rizo, Alberto Palacios.

    San Diego Mesa College, San Diego, CA.

    Ascorbic acid is a water soluble molecule and exhibits natural antioxidant properties that apply to many biomedical treatments. It is a gamma-lactone with a unique 2,3-ene-diol group that is oxygen-reactive. Fatty acid esters of ascorbic acid have been found to inhibit the activity of glycolytic enzymes PFK-1 and LDH. The purpose of this work is to investigate the synthesis of 2-mono and 2,6-disubstituted fatty acid esters of ascorbic acid using a concentrated sulfuric acid method. We found that when a 1:1 molar mixture of lauric acid and ascorbic acid is stirred in concentrated sulfuric acid under nitrogen for 18 hours, 6-mono ascorbic acid laurate (I) is produced at 55% yield. When the ratio of lauric acid to ascorbic acid is 2:1, only the 6-mono ascorbic acid laurate is produced with no disubstituted ester. Also, when a 1:1 mixture of 6-mono ascorbic acid laurate (II) and lauric acid is stirred with concentrated sulfuric acid for 18 hours under nitrogen, no disubstituted ester is produced. We hypothesized that these reactions are general in the synthesis of the fatty acid esters of ascorbic acid. Our hypothesis was confirmed in studies on the synthesis of corresponding caprylate and palmitate esters. A mechanism involving carbocation and sulfate ester intermediates is postulated to explain the results.

    THU-508 ESTIMATION OF HYDROPHILIC LIPOPHILIC BALANCE OF GASOLINE DETERGENT ADDITIVES VIA ALKOXY GROUP ASSAY BY GC-MS

    • Noman Al ;
    • Barbara Belmont ;

    THU-508

    ESTIMATION OF HYDROPHILIC LIPOPHILIC BALANCE OF GASOLINE DETERGENT ADDITIVES VIA ALKOXY GROUP ASSAY BY GC-MS

    Noman Al, Barbara Belmont.

    California State University, Dominguez Hills, Carson, CA.

    The EPA requires all gasolines to contain detergent to minimize engine valve and combustion chamber buildup because clean engines have been demonstrated to have better fuel economy. A leading gasoline brand uses a polyether amine detergent claimed by marketing and patents, as well as anecdotally by consumers and automotive mechanics, to be superior to the competition. A polyether amine has the general structure H3CR’(CH2CH2O)nNH2, where R’ is an alkyl chain. The amine head is slightly polar and basic and may serve as an anticorrosion chemical when in contact with the engine interior surfaces. The repeating alkoxy unit and the length of the alkyl chain influence the solubility of the detergent in gasoline and the deposit solubilizing capability of the detergent. Solubility and solubilizing capability of detergents are also predicted by their hydrophilic lipophilic balance (HLB) value. Therefore, the gasoline detergent with the HLB value most appropriate to the system can be predicted to perform better. This project attempts to characterize the HLB values of the leading brand of gasoline detergent and a generic unbranded gasoline detergent through quantification of the ethoxy groups, using gas chromatography-mass spectrometry of the derivatives acylated by reaction of acetyl chloride in the presence of a Lewis acid (FeCl3).

    THU-511 CHARACTERIZATION OF MAGNETITE FROM COLUMBIA RIVER SEDIMENTS

    • Maya Navarro ;
    • Miranda Bradley ;
    • Paul Tratnyek ;

    THU-511

    CHARACTERIZATION OF MAGNETITE FROM COLUMBIA RIVER SEDIMENTS

    Maya Navarro1, Miranda Bradley2, Paul Tratnyek2.

    1DePaul University, Chicago, IL, 2Institute of Environmental Health, Oregon Health and Science University, Portland, OR.

    Sediments in the Columbia River contain iron oxides, which are significant to the biogeochemistry of the ecosystem. Magnetite (Fe3O4), an iron oxide mineral, has unique redox properties, specifically because it contains both ferrous (Fe2+) and ferric (Fe3+) iron that allows it to sequester contaminants such as uranium by reduction. In this study, the variability of the redox properties of magnetite are measured in sediment samples from 6 locations along the Columbia River as well as in samples that have intentionally been oxidized or reduced prior to experimentation. We hypothesize that these properties will vary based on the mineral composition and condition of the outer shell of material that coats the particles, which is oxidized when exposed to oxygen or when reducing another material in the environment. Powder disk electrodes (PDEs) of each sample are tested in a 3-electrode cell using linear polarization resistance, linear sweep voltammetry, electrical impedance spectroscopy, and cyclic voltammetry techniques. The resulting plots are used to determine how electrons behave at the surface of the material and the potential for environmental reactivity. The differences in these different types of surface composition are expected to be observable using these forms of electrochemical testing. Preliminary results show a correlation between the material’s ability to conduct charge and its geographic origin. The variability in these data suggests the possibility of differences among the redox properties of magnetite from various locations.

    THU-515 NOVEL SPECTROSCOPIC AND ELECTROCHEMICAL DETERMINATION FOR WATER-BOUND ENVIRONMENTAL CONTAMINANTS

    • Nguyen Luu ;
    • Mian Jiang ;

    THU-515

    NOVEL SPECTROSCOPIC AND ELECTROCHEMICAL DETERMINATION FOR WATER-BOUND ENVIRONMENTAL CONTAMINANTS

    Nguyen Luu, Mian Jiang.

    University of Houston-Downtown, Houston, TX.

    Water-bound contaminants are high risks to human health and societal sustainability because of their ease of dispersal and biocompatibility. These residues are usually oxidizing species, stemming from the agriculture and defense industries. The need to quantify them has significance ranging from drinking water compliance to waste minimization. In this work, we developed a new assay for these oxidants by using UV-Vis spectroscopy, fluorescence, and electrochemistry. We systematically examined the use of conventional protein-staining dyes such as the azures and found they were sensitive to oxidants, including nitrite, azide, and hypochlorites. These thiazine-containing dyes are quenched on introduction of the oxidants. By using electrochemical and kinetic analysis, this quenching can be developed into a new assay for the oxidants. Our preliminary study revealed the complicated responding mechanism. While these oxidants (analytes) can directly oxidize these dyes, they actually play a role more like the quenchers of the existent fluorescence of the dyes impacted by the presence of a stronger third oxidizer agent. Our follow-up study optimized the analytical system. The highest sensitivity has been obtained in acidic media with a ternary component system matrix. Our new protocols for nitrite and hypochlorite are representative and can be extended to other oxidizers, which adds new means to address the water bound environmental protection problem. [This work was supported by NRC-MSIP, NOAA B-WET, NASA-TSGC-NIP, and Welch Grant (BJ-0027).]

    FRI-516 EXPEDIENT ACCESS TO THE 1,2-OXAZADECALIN CORE AND STUDIES TOWARD 1,2-OXAZADECALIN SECONDARY METABOLITES

    • Jessica Burch ;
    • Adelphe M. Mfuh ;
    • Anh Vo ;
    • Oleg Larionov ;

    FRI-516

    EXPEDIENT ACCESS TO THE 1,2-OXAZADECALIN CORE AND STUDIES TOWARD 1,2-OXAZADECALIN SECONDARY METABOLITES

    Jessica Burch, Adelphe M. Mfuh, Anh Vo, Oleg Larionov.

    The University of Texas at San Antonio, San Antonio, TX.

    Trichodermamide A, B, and C are a unique set of natural products that are isolated as secondary metabolites from the marine fungus Trichoderma virens. They contain a rare 1,2-oxazine moiety fused to a densely functionalized cyclohexene scaffold with 4 contiguous stereocenters. Trichodermamide B and C show significant antiproliferative activity against HCT 116 with IC50 values of 0.32 and 0.68 mg/mL, respectively. Aspergillazines A-E, which are structurally related to trichodermamides, are also known to have cytotoxic properties. The isolation of trace amounts of these secondary metabolites from ecologically fragile entities is an obstacle to further studies of these compounds as therapeutic agents. The goal of this project is to develop an expedient route to the synthesis of 1,2-oxazadecalin secondary metabolites. Salient features include its overall conciseness, limited chromatography, and employment in protecting group-free strategies.

    FRI-524 BOND WEAKENING CATALYSIS: ACTIVATION OF AN ALLYLIC C-H BOND

    • David Danielson ;
    • Lucas Nguyen ;
    • Robert Knowles ;

    FRI-524

    BOND WEAKENING CATALYSIS: ACTIVATION OF AN ALLYLIC C-H BOND

    David Danielson1, Lucas Nguyen2, Robert Knowles2.

    1The University of New Mexico, Albuquerque, NM, 2Princeton University, Princeton, NJ.

    Hydrogen atom transfer (HAT) is a fundamental mechanism for many radical reactions including those found in biological systems. Bond weakening catalysis provides a promising method to achieve selective HAT by substrate activation. Although there are many potential applications of this phenomenon in synthetic organic chemistry, to this point they have remained largely unexplored. Previously, our group has shown the effectiveness of bond-weakening catalysis for conjugate aminations using a titanocene complex to weaken a strong N-H bond, enabling HAT to a weak abstractor. It is our goal to apply this method to allylic C-H bonds. Calculations preformed at the UBLYP/6-31G+(d,p) level have shown the ability of various first-row transition metals to weaken the H-atom bonds on the allylic carbon of cyclohexene by as much as 35 kcal/mol. This enables proton abstraction by a weak H-atom acceptor such as TEMPO to generate a radical allyl intermediate. We are currently in the process of testing the reactivity of this intermediate with different reagents. If successful, this project will establish more support for bond weakening as a platform for the activation and functionalization of substrates, and it will allow us to apply H-atom transfer to systems that are traditionally inaccessible.

    FRI-528 DETERMINING THE MOLAR EXTINCTION COEFFICIENT AND EMISSION OF SOME PHENYLALANINE DERIVATIVE AMINO ACIDS USING UV-VIS AND FLUORESCENCE SPECTROSCOPIES

    • Joselin Vargas ;
    • Ruel Desamero ;
    • Jinnette Tolentino-Collado ;

    FRI-528

    DETERMINING THE MOLAR EXTINCTION COEFFICIENT AND EMISSION OF SOME PHENYLALANINE DERIVATIVE AMINO ACIDS USING UV-VIS AND FLUORESCENCE SPECTROSCOPIES

    Joselin Vargas1, Ruel Desamero2, Jinnette Tolentino-Collado2.

    1Queensborough Community College, Bayside, NY, 2York College, City University of New York, Jamaica, NY.

    Human islet amyloid polypeptide (hIAPP) or amylin is a peptide hormone cosecreted with insulin. Amylin is known to misfold and aggregate into amyloid deposits found in patients with type-2 diabetes. Recent studies have shown that hIAPP contains different sites of aggregation and each site contains an aromatic ring; Phe-15, Phe-23, andTyr-37; that is involved in the process of aggregation. Our objective was to assess the role of the aromatic residue Phe in driving amyloid formation. Sets of variant heptapeptides were synthesized with various phenylalanine derivatives and studied with spectroscopic techniques. To track peptide concentration in our measurements, we relied on molar extinction coefficients of the phenylalanine surrogates. Our focus was to measure the molar extinction coefficients ε of the phenylalanine derivatives using UV-Vis spectroscopy and to employ fluorescence spectroscopy to study the effect of modifying the phenylalanine amino acid. The molar extinction coefficients of the following derivatives Phe, Phe(OH), Phe(NO2), Phe(OCH3), Phe(CH3), and His were calculated by plotting a calibration curve of absorbance vs. concentration of amino acid. The slope of the calibration curve is equal to the εl where l is pathlength. Therefore, the molar extinction coefficients of Phe, Phe(OH), Phe(NO2), Phe(OCH3), Phe(CH3), and His were found to be 133, 1242, 12620, 1390, 300, and 5605 respectively. Our results indicate that UV-Vis and fluorescence spectroscopy are promising techniques for determining the molar extinction coefficient, and therefore the concentration, of some phenylalanine derivatives. This ongoing research may provide new insights in amyloid formation and a molecular target for future therapy.

    FRI-510 THE PREORGANIZATION OF ALPHA-HELIX MIMETICS AROUND A CHIRAL AXIS: TOWARD SELECTIVE INHIBITORS OF PROTEIN-PROTEIN INTERACTIONS

    • Arianna Ayonon ;
    • Mari Gabra ;
    • Jeffrey Gustafson ;

    FRI-510

    THE PREORGANIZATION OF ALPHA-HELIX MIMETICS AROUND A CHIRAL AXIS: TOWARD SELECTIVE INHIBITORS OF PROTEIN-PROTEIN INTERACTIONS

    Arianna Ayonon, Mari Gabra, Jeffrey Gustafson.

    San Diego State University, San Diego, CA.

    Atropisomerism is a stereochemical phenomenon that arises from differential substitution around a single bond. As this axis is rotatable, atropisomers can exist as either stable isolable species or rapidly interconverting mixtures. The stereochemical stability of a chiral axis is primarily determined by the size of the substituent adjacent (ortho) to the axis. Rapidly interconverting atropisomerism is common throughout biologically active scaffolds; however, while only one atropisomer possesses the desired activities, the other displays no activity or even off-target effects. Our goal is to investigate the effects of atropisomer conformation on the selectivity of α-helix mimetics. Control of atropisomer conformation via the synthesis of sterochemically stable terephthalamide analogs will lead to improved target selectivities. Results have shown these analogs to have unexpectedly high stereochemical stabilities compared to literature compounds with similar substitutions adjacent to the axis. Further investigation showed analogs with significantly decreased steric bulk, exchanging chlorine for bromine, were also surprisingly stable. Characterization of these α-helix mimetics is accomplished through 1H nuclear magnetic resonance (1H NMR) and chiral high performance liquid chromatography (HPLC). Current synthesis of further point-mutant analogs is underway to explore the nonobvious factors that are affecting this unexpected stereochemical stability.

    THU-512 THE EFFECT OF METAL CATIONS ON CAPILLARY ELECTROOSMOTIC FLOW

    • Eduardo De La Toba ;
    • Shane Wells ;
    • Christopher Harrison ;

    THU-512

    THE EFFECT OF METAL CATIONS ON CAPILLARY ELECTROOSMOTIC FLOW

    Eduardo De La Toba, Shane Wells, Christopher Harrison.

    San Diego State University, San Diego, CA.

    Capillary electrophoresis (CE) is an incredibly powerful tool in the field of chromatography due to its potential for high-resolution separations of analytes and the requirement for very small volumes of sample for analysis. Despite these attributes, one issue when performing separations with CE is that proteins can bind to the negatively charged silica surface on the interior of the capillary. To overcome this obstacle, phospholipids are used to prevent the binding of proteins to the surface. Traditionally, phospholipid bilayers are stabilized by calcium ions that are incorporated into the phospholipid bilayer in order to minimize the charge repulsion of the negatively charged phosphate groups on the heads of the phospholipids. It is known that the magnitude and direction of the electroosmotic flow (EOF) is influenced by the presence of calcium ions in the phospholipid bilayer. The objective of this work was to investigate how different metal cations might integrate into the bilayer and influence the EOF and the stability of the bilayer. We predicted that the incorporation of noncalcium metal cations into the bilayer would yield an overall positive charge of the bilayer and, in turn, the EOF based on the magnitude of the incorporation of the different metals. This has been supported by our work using a range of different divalent and trivalent metal cations in the separation buffer. We have shown that there is a significant impact on the magnitude of the EOF depending on the choice of the metal cation and with various EOF values.

    FRI-509 MECHANISM AND ENERGETICS OF CHLOROCARBENE ADDITIONS TO DIBENZOCYCLOOCTYNE

    • Andromeda Urquilla ;
    • Dina Merrer ;

    FRI-509

    MECHANISM AND ENERGETICS OF CHLOROCARBENE ADDITIONS TO DIBENZOCYCLOOCTYNE

    Andromeda Urquilla, Dina Merrer.

    Barnard College, New York, NY.

    Carbenes contain a highly reactive neutral divalent carbon atom with a non-bonding pair of electrons that may be either the singlet or triplet spin state. Understanding carbene reactivity helps explain why reactions exhibit behavior that is not well described by transition state theory, such as carbene additions to strained carbon-carbon (C-C) π bonds. This work utilizes computational methods to study dichlorocarbene (CCl2) and phenylchlorocarbene (PhCCl) additions to dibenzocyclooctyne (DIBO). We have computed the potential energy surfaces (PESs) of CCl2 and PhCCl additions to DIBO at B3LYP/6-31G(d) and M06-2X/6-31G(d) at 3 different electronic states: closed-shell singlet, open-shell singlet, and triplet. The PESs show different free energy barriers depending on the electronic spin state. Regardless of spin state, the predominant cycloaddition product, a cyclopropene, is the global energy minimum on the PESs with an intermediate vinylcarbene as a local energy minimum. We observed evidence of a mechanistic bifurcation at the transition state of chlorocarbene addition to DIBO; the same transition state leads to both the vinylcarbene and cyclopropene. Direct dynamics calculations with our collaborators (K. N. Houk and Z. Yang, University of California, Los Angeles), and our ongoing calculations suggest that these carbene additions to DIBO are controlled by dynamic effects.

    FRI-522 SYNTHESIS OF NOVEL NON-INNOCENT LIGANDS FOR METAL-CATALYZED HYDROFORMYLATION

    • David Delgadillo ;
    • Ramiro Barraza ;
    • Ryan Baxter ;

    FRI-522

    SYNTHESIS OF NOVEL NON-INNOCENT LIGANDS FOR METAL-CATALYZED HYDROFORMYLATION

    David Delgadillo1, Ramiro Barraza, Ryan Baxter.

    University of California, Merced, Merced, CA.

    Many pharmaceuticals such as salicylic acid acetate, aspirin, are composed of esters, aldehydes, and carboxylic acids. Hydroformylation is one of the processes used to synthesize these organic functional groups; which encompasses the addition of a formyl group and a hydrogen atom to a carbon-carbon double bond. The biggest concern with the current formylation process is that the catalysts are either inefficient or are very expensive. In this presentation, we will discuss our work on a variety of symmetrical and asymmetrical non-innocent ligands. These non-innocent ligands have been shown to be redox active, which allow the ligands to participate in the catalytic cycle. With that being the case, we are investigating these non-innocent ligands and their potentiality as catalysts for optimizing mechanistic selectivity in asymmetric hydroformylation. It is significant to research non-innocent ligands because they offer novel catalyst alternatives that are efficient and inexpensive. Producing more efficient and affordable catalysts for the hydroformylation would reduce the use of precious metals such as rhodium and improve the availability of organic functional groups by expanding catalytic resources.

    FRI-521 DESIGNING MOLECULAR PHOTOACOUSTIC CONTRAST AGENTS FOR DEEP-TISSUE BIOLOGICAL IMAGING BY ENGINEERING PHOTOPHYSICAL PROPERTIES OF CURCUMINOID CHROMOPHORES

    • Farha Mithila ;
    • Stephanie Bellinger-Buckley ;
    • Matthieu Frenette ;
    • Maryam Hatamimoslehabadi ;
    • Chandra Yelleswarapu ;
    • Jonathan Rochford ;

    FRI-521

    DESIGNING MOLECULAR PHOTOACOUSTIC CONTRAST AGENTS FOR DEEP-TISSUE BIOLOGICAL IMAGING BY ENGINEERING PHOTOPHYSICAL PROPERTIES OF CURCUMINOID CHROMOPHORES

    Farha Mithila, Stephanie Bellinger-Buckley, Matthieu Frenette, Maryam Hatamimoslehabadi, Chandra Yelleswarapu, Jonathan Rochford.

    University of Massachusetts Boston, Boston, MA.

    Photoacoustic imaging (PAI) is a new emerging technique that combines optical absorption and ultrasonic emission to enable high resolution imaging in biological media. Targeted PAI requires engineering of exogenous photoacoustic contrast agents that are capable of converting light energy to sound energy. However, there is currently a lack of optimal contrast agents available specifically designed for PAI applications. Quadrupolar dyes, such as the curcumin-BF2 chromophore, have recently been shown to possess important characteristics necessary for molecular photoacoustic contrast agents (MPACs). This study demonstrates that selective functionalization at the terminal positions of the curcuminoid chromophore, one can tune their absorption spectra toward the ideal transparent biological window. With this in mind, novel curcumin chromophores have been synthesized by adding aryl and heterocyclic substituents at the terminal position of the b-diketonate difluoroboron backbone to investigate changes in their photophysical and photoacoustic properties. The 5-methyl-2,2’-bithiophene substituent shows significant promise as it shifts the absorption maximum toward the biological window, similar to the dimethylaminobenzene substituent, in contrast to the p-butoxyphenyl substituted system. Emission and absorption properties have been investigated along with computational analysis and preliminary photoacoustic studies.

    THU-510 KINETIC ISOTOPE EFFECTS AND DYNAMICS FOR FRIEDEL-CRAFTS ACYLATION

    • Ashley Sanchez ;
    • Daniel Singleton ;
    • Yexenia Nieves ;

    THU-510

    KINETIC ISOTOPE EFFECTS AND DYNAMICS FOR FRIEDEL-CRAFTS ACYLATION

    Ashley Sanchez1, Daniel Singleton2, Yexenia Nieves2.

    1University of Puerto Rico at Humacao, Humacao, PR, 2Texas A&M University, College Station, TX.

    Electrophilic aromatic substitution reactions of veratrole were studied by a combination of experimental kinetic isotope effects (KIEs), standard theoretical calculations, and dynamic trajectory calculations. The acylation of veratrole with acetyl chloride using aluminum chloride exhibits an inverse intramolecular 12C/13C kinetic isotope effect of 0.990-0.991 and an intermolecular isotope effect of unity. However, the acylation of veratrole using silver perchlorate showed an intramolecular 12C/13C kinetic isotope effect of unity. This difference in the KIE suggests that the nature of the active electrophile has changed with the differing catalysts. In addition, product ratios were measured for the acylation of butyl phenyl ether in order to see if a change in the catalyst affects the product distribution, and it was found that the product ratios change significantly with the change in catalyst. These results are inconsistent with the conventional mechanism, and they implicate dynamic control of the regioselectivity subsequent to the rate-limiting step.

    FRI-515 PD-CATALYZED ASYMMETRIC B-HYDRIDE ELIMINATION EN ROUTE TO CHIRAL ALLENES

    • Ana Maldonado ;
    • Kristina Marquez ;
    • Ian Crouch ;

    FRI-515

    PD-CATALYZED ASYMMETRIC B-HYDRIDE ELIMINATION EN ROUTE TO CHIRAL ALLENES

    Ana Maldonado, Kristina Marquez, Ian Crouch.

    The University of Texas at San Antonio, San Antonio, TX.

    Van ’t Hoff first predicted the unique structure of an allene in 1875. He proposed the composition of 2 C=C bonds connected by an sp hybridized carbon center with the 2 π-systems orthogonal to one another. Today, allenes are no longer hypothetical and have actually been discovered in over 150 natural products such as peridinin and fucoxanthin. In addition, they have been used in commercially available drugs. Due to their unique structure, allenes undergo multiple synthetic transformations. Because of this, they provide a huge incentive to develop synthetic routes to access them. Such routes lack development through the use of catalysts to facilitate enantioselective synthesis of allenes. Since then, several reviews have appeared in literature each containing a few examples of catalytic syntheses. Going through them, it is easy to see that di- and tri- substituted asymmetric allene syntheses have had moderate success with several novel protocols. These results highlight our recent efforts to develop a new route through asymmetric synthesis. [Partially funded by GM060655 and National Science Foundation (CHE-1362953).]

    THU-522 SYNTHESIS OF FLUORINATED PHARMACEUTICAL PRECURSORS VIA RADICAL PATHWAYS

    • Ramon Martinez ;
    • Alyssa Hua ;
    • Jerry Vue ;
    • Ryan Baxter ;

    THU-522

    SYNTHESIS OF FLUORINATED PHARMACEUTICAL PRECURSORS VIA RADICAL PATHWAYS

    Ramon Martinez1, Alyssa Hua1, Jerry Vue2, Ryan Baxter1.

    1University of California, Merced, Merced, CA, 2Golden Valley High School, Merced, CA.

    Research and development of pharmaceutical precursors have always been integral components in the advancement of organic synthesis, especially with direct α-alkylation of heterocyclic aromatic compounds via metal catalyzed C-H radical reactions which offer a controlled pathway to form these pharmaceutical precursors. Fluorinated natural compounds show outstanding properties including modulating basicity/acidity of parent molecule, lipophilicity, and modulation of metabolic stability. As a result, there has been an increase in the demand for procedures to synthesize these compounds. The process we use to form these compounds is direct α-alkylation through radical species which is carried out in a mechanism similar to Michael addition of nucleophiles and electrophiles where the radical species formed is the nucleophile and the electron deficient aromatic is the electrophile. These reactions are typically metal catalyzed and controlled in order to synthesize desired molecules, but most procedures used today are not viable in large-scale or even small-scale synthesis, because procedures call for inert atmospheric conditions, large molar quantities of substrates, or use of expensive catalysts. In this research, we investigated methods that will allow us to optimize a general procedure that is both viable, efficient, and most of all applicable to many combinations of heterocyclic aromatics and α-proton sources. Our research focuses on using silver nitrate as the catalytic source and on adjustment of reaction variables in order to achieve the optimized procedure. With this generalized α-alkylation procedure, we are synthesizing fluorinated precursors, which usually take multiple steps, in just one concise aqueous step.

    FRI-520 SYNTHESIS AND CHARACTERIZATION OF ALUMINUM KEGGIN CLUSTERS

    • Mohammed Sahar ;
    • Brantly Fulton ;

    FRI-520

    SYNTHESIS AND CHARACTERIZATION OF ALUMINUM KEGGIN CLUSTERS

    Mohammed Sahar1, Brantly Fulton2.

    1University of Massachusetts Amherst, Amherst, MA, 2University of Oregon, Eugene, OR.

    Various aluminum clusters are found in nature due to the degrading effects of acid rain on minerals. Recent studies allude to links between Al3+ exposure and higher rates of fish mortality, hampered plant growth, and physiological mutations in humans. Long-term exposure is also associated with Parkinson’s and Alzheimer’s diseases. Understanding the properties of aluminum clusters is critical for combating their effects on plants and animals. The primary cluster of interest is Keggin-Al13 ([Al134-O)42-OH)24(H2O)12]7+), which is synthesized using an acid-base titration of NaOH into AlCl3, under constant heating and stirring. These clusters are easier to characterize and study than others due to their unique features, including pH, size, and a tetrahedral center. Most aluminum-based clusters are octahedrally coordinated, making them difficult to distinguish from monomers. The characteristic tetrahedral center of Keggin clusters is seen at a chemical shift of 63 ppm in 27Al-NMR. The expected pH range of Keggin clusters is ~3.8 - 4.2, and if found to be thermodynamically stable at this range, Keggin clusters can be placed on the Pourbaix diagram of aluminum. Keggin clusters in solution can be observed using dynamic light scattering (DLS). This technique measures the radius of the shell of the clusters in solution which include the core as well as the surrounding solvent (hydration sphere). Solid state studies have been done on Keggin clusters; however, solution studies like these are unprecedented and can offer insight into the solution to some of the negative effects of Keggin clusters on physiology.

    FRI-517 METAL ORGANIC FRAMEWORKS: ANION EXCHANGERS FOR ENVIRONMENTAL APPLICATIONS

    • Aubrey Alvarenga ;
    • Scott Oliver ;

    FRI-517

    METAL ORGANIC FRAMEWORKS: ANION EXCHANGERS FOR ENVIRONMENTAL APPLICATIONS

    Aubrey Alvarenga, Scott Oliver.

    University of California, Santa Cruz, Santa Cruz, CA.

    Perchlorate, a byproduct of rocket fuel, has a history of contaminating drinking water and causing hypothyroidism by inhibiting the uptake of iodine in the thyroid gland. In children, hypothyroidism leads to intellectual and developmental delays. Silver bipyridine acetate (SBA), a potentially new analog of the previously studied silver bipyridine nitrate (SBN), was considered for an environment-friendly ion exchange material to exchange the pollutant perchlorate, an oxoanion. It was believed that acetate, bonded electrostatically between the layers of the metal-organic framework (MOF), would exchange for perchlorate. For initial studies, the oxoanion permanganate (in the same family as perchlorate) was used first, due to reduced toxicity and easier analysis. The oxoanion exchange reaction ran simultaneously for both SBN and SBA under identical conditions and was analyzed quantitatively using ultraviolet-visible spectroscopy and qualitatively using powder X-ray diffraction. SBA exchanged permanganate at an appreciable rate relative to SBN. For the environment, acetate proves to be a better alternative anion than nitrate in the exchange of perchlorate.

    FRI-507 INSIGHT OF P-GLYCOPROTEIN STRUCTURE VIA HOMOLOGY MODELING

    • Rigoberto Arenas ;
    • Ba Yong ;

    FRI-507

    INSIGHT OF P-GLYCOPROTEIN STRUCTURE VIA HOMOLOGY MODELING

    Rigoberto Arenas, Ba Yong.

    California State University, Los Angeles, Los Angeles, CA.

    P-glycoprotein (Pgp) is a plasma membrane efflux transporter which is known to have important effects on the absorption, distribution, metabolism, and excretion of many important natural and synthetic compounds. Pgps are found in many important tissues such as the liver, kidneys, intestines and the blood-brain barrier to export foreign chemical substrates out of the cells. As a xenobiotic transporter, Pgp has effects on many chemotherapy drugs. While there is no effective experimental method for this study, computational simulations are a method currently used to investigate possible reasons why Pgp is able to interact with a wide range of substrates with no structural similarity. This study is particularly important for generating and validating a homology Pgp model which can later be used to further the investigation on the blinding and docking studies of drugs with Pgp. The homology model was constructed using Accelry’s Discovery Studio software. The sequence alignment with template showed an 82.7% and 88.5% sequence identity and sequence similarity, respectively. The software programs PROCHECK and QMEAN were used for Pgp model validation. Scores by both PROCHECK and QMEAN provide tools to measure the quality of the Pgp model. The PROCHECK calculation shows that 85.2%, 10.8%, 3.1%, and 0.8 % residues are most favorable, additionally allowed, generally allowed, and disallowed regions, respectively. The overall Omean score was 0.468, where value scores range from 0 - 1. Overall results indicate that the model was good quality.

    THU-516 USING MOLECULAR FIELD SIMILARITY TO IDENTIFY ADVERSE EFFECTS OF CENTRAL NERVOUS SYSTEM DRUGS

    • Rachel Nelson ;
    • Anang Shelat ;

    THU-516

    USING MOLECULAR FIELD SIMILARITY TO IDENTIFY ADVERSE EFFECTS OF CENTRAL NERVOUS SYSTEM DRUGS

    Rachel Nelson1, Anang Shelat2.

    1Rhodes College, Memphis, TN, 2St. Jude Children's Research Hospital, Memphis, TN.

    Topologically dissimilar compounds may show similar biological effects. This behavior, called cross-reactivity, is difficult to predict based on the topology of the molecules alone. However, methods that capture the ligands’ physico-chemical distributions that interact with the binding site, instead of topological similarities, may be better able to capture the underlying similarities among cross-reactive molecules. In this study, we investigate whether adverse effects from drugs that target the central nervous system (CNS) are governed by their underlying similarities in physico-chemical property distributions and shape. We compute molecular interaction field models that employ field-point technology from Cresset software to capture physico-chemical distributions and shape of the bioactive conformers of 100 CNS drugs. The field points are located at areas of energy extrema that are likely sites of ligand-target interactions. We found that comparing CNS drugs using molecular interaction fields showed higher correlation with adverse activity than fingerprint based topology similarity. Thus, molecular interaction fields can be used as a tool to understand the underlying similarities in structures and potentially predict adverse effects of CNS drugs.

    THU-507 A NEW OCTAHEDRAL COBALT(III) COMPLEX AS A POSSIBLE ANTI-CANCER PRODRUG: SYNTHESIS AND CHARACTERIZATION STUDIES IN SOLID STATE AND SOLUTION

    • Natalie Joe ;
    • Aimee Morris ;

    THU-507

    A NEW OCTAHEDRAL COBALT(III) COMPLEX AS A POSSIBLE ANTI-CANCER PRODRUG: SYNTHESIS AND CHARACTERIZATION STUDIES IN SOLID STATE AND SOLUTION

    Natalie Joe, Aimee Morris.

    Fort Lewis College, Durango, CO.

    Coordination complexes with redox active metal centers are gaining interest for their potential uses in anti-cancer research. KP1019 and NAMI-A are two ruthenium(III) coordination complexes with indazole and dimethylsulfoxide ligands, respectively, that are currently in phase II clinical trials for their antitumor or antimetastatic properties. Using a more abundant, less expensive cobalt metal center in place of ruthenium(III), we hypothesize that similar cobalt(III) complexes can be synthesized. A new solid, isolable complex was achieved using a ligand substitution reaction via refluxing and crystallization techniques. The new product is an octahedral Co(III) coordination complex that contains indazole and labile dimethylsulfoxide ligands. The proposed structure of the Co(III) complex is supported by elemental analysis and magnetic susceptibility measurements in the solid state along with solution characterization studies including 1H and 13C NMR and mass spectrometry. This complex displays promise in using a new metal center for expanding metal-containing prodrugs. Further studies are in progress to determine the exact speciation in the solid-state and in solution, as well as investigating the efficacy of this new compound on cancer cell lines.

    THU-520 SYNTHESIS AND BIOLOGICAL ACTIVITY OF NEW FLUORESCENT ABQ-48 (NSC D-763307) DERIVATIVES: 7-(2,3,4-TRIMETHOXYBENZYL- AND 3,4,5-TRIMETHOXYBENZYL)-3-AMINOBENZIMIDAZO[3,2-A]QUINOLINIUM CHLORIDE

    • Joanie M. Nina Ruperto ;
    • Osvaldo Cox ;

    THU-520

    SYNTHESIS AND BIOLOGICAL ACTIVITY OF NEW FLUORESCENT ABQ-48 (NSC D-763307) DERIVATIVES: 7-(2,3,4-TRIMETHOXYBENZYL- AND 3,4,5-TRIMETHOXYBENZYL)-3-AMINOBENZIMIDAZO[3,2-A]QUINOLINIUM CHLORIDE

    Joanie M. Nina Ruperto1, Osvaldo Cox2.

    1School of Sciences and Technology, Universidad Metropolitana, San Juan, PR, 2School of Environmental Affairs, Universidad Metropolitana, San Juan, PR.

    Benzazolo[3,2-a]quinolinium salts (BQS) are unnatural alkaloids that have shown great potential as anticancer agents. To test their anticancer activity, several members of this family of compounds have been evaluated through the National Cancer Institute (NCI) 60 cell line screening, which represents diverse histologies. Results from the NCI screening indicated that among all BQSs tested, 7-benzyl-3-aminobenzimidazo[3,2-a]quinolinium chloride (ABQ-48: NSC D-763307) showed promising cytotoxic activity overall. In order to explore the possibilities of a new derivative of ABQ-48 with increased biological activity and enhanced fluorescence properties, a synthetic procedure was developed for the preparation of 7-(3,4,5- and 2,3,4-trimethoxybenzyl)-substituted ABQ-48: also known as ABQ-48-3-345-TOM and ABQ-48-3-234-TOM, respectively. The first step in the synthetic sequence was the preparation of a 1-aryl-2-methylbenzimidazole. Next, 2-chlro-5-nitrobenzadehyde was condensed in boiling acetic anhydride, producing a 1-aryl substituted-2-(2-chloro-5’-nitrostyryl)benzimidazole. The next step towards the synthesis is crucial; it involves the reduction of the nitro group via an Ni2B- catalyzed reduction in the presence of hydrazine hydrate in boiling methanol under an argon atmosphere. All the new compounds were characterized by spectroscopic data [1D and 2D proton and carbon-13 nuclear magnetic resonance (NMR), infrared spectroscopy (IR), and visible and ultraviolet spectroscopy (UV-vis)]. A comparison of the behavior of NBQ-48-3-345 TOM and ABQ-48-3-345 TOM in the NCI 60 cell line screen is presented here. The synthesis of NBQ-48-3-234 TOM and ABQ-48-3-234 TOM is already in progress and will be presented in a future presentation.

    THU-517 CYCLIC(ALKYL)(AMINO)CARBENE-COPPER COMPLEXES FOR CATALYSIS

    • Glen Junor ;
    • Cory Weinstein ;
    • Rodolphe Jazzar ;
    • Mohand Melaimi ;
    • Guy Bertrand ;

    THU-517

    CYCLIC(ALKYL)(AMINO)CARBENE-COPPER COMPLEXES FOR CATALYSIS

    Glen Junor1, Cory Weinstein2, Rodolphe Jazzar2, Mohand Melaimi2, Guy Bertrand1.

    1University of California, Irvine, Irvine, CA, 2University of California, San Diego, La Jolla, CA.

    Low turnover numbers (TONs) plague homogeneous catalysis due to fast decay of the active metal species into inactive forms of metal(0), imposing high precatalyst loadings. Sophisticated ligands have been designed to circumvent this issue and allow the use of transition metal complexes at the ppm level while reaching high TONs. More specifically, copper catalysts have mostly been used in specific types of reactions leading to C-O or C-N bond formation (e.g., alkyne hydroalkoxylation and hydroamination). There is, to date, no general and attractive catalytic system which would be both redox stable and highly active in C–C bond forming reactions. To address these limitations, new air-stable copper cyclic(alkyl)(amino) carbene (CAAC) complexes (CAAC)CuX have been synthesized from cheap starting materials. Following previous work where (NHC)AuCl has been used in the cyclization of 1,5-diynes, leading to valuable photovoltaic and pharmaceutical synthons, we hypothesixe that our linear copper complex will have similar reactivity, thus making it an attractive, cheaper alternative to the currently used (NHC)AuCl. Characterization by 1H-NMR, 13C-NMR, and single crystal X-ray diffraction studies are reported along with preliminary reactivity data.

    THU-519 STUDIES TOWARDS THE SYNTHESIS OF 8-AZA-NBQ AND 8-AZA-ABQ-48 DERIVATIVES

    • Kimberly Guadalupe ;
    • Osvaldo Cox ;

    THU-519

    STUDIES TOWARDS THE SYNTHESIS OF 8-AZA-NBQ AND 8-AZA-ABQ-48 DERIVATIVES

    Kimberly Guadalupe1, Osvaldo Cox2.

    1Escuela de Cienicias y Tecnologia, Universidad Metropolitana, San Juan, PR 2School of Environmental Affairs, Universidad Metropolitana, San Juan, PR.

    Prior results from the National Cancer Institute (NCI) screening indicate that among all benzazolo[3,2-a]quinolinium salts (BQS) tested, 7-benzyl-3-aminobenzimidazo[3,2-a]quinolinium chloride (ABQ-48: NSC D-763307) showed promising cytotoxic activity overall. The objective in this research was to modify the structure of ABQ-48 by replacing a carbon atom by nitrogen at the D-ring to produce an 8-aza-ABQ-48 derivative. A retrosynthetic analysis led us to devise a possible synthetic route into this compound. The first step in this retrosynthetic analysis is the preparation of 2-(N-benzylamino)-3-nitropyridine (1). The next step involves the reduction of 1 to yield 2-(N-benzylamino)-3-aminopyridine (2). Reaction of compound 2 with acetic anhydride in acetic acid should produce 1-phenyl-2-methyl-6-azabenzymidazole (3). Following the usual procedure for the synthesis of BQS derivatives in our laboratory, compound 3 is condensed with 2-chloro-5-nitrobenzaldehyde to produce compound 4, which in turn will be cyclized to yield the desired 3-nitro-8-aza NBQ-48. The synthesis of compound 1 and its characterization by 1H- and 13C-NMR and X-ray crystallography will be presented.

    FRI-508 NOVEL DEOXYGENATION-DIMERIZATION OF BENZOISOTHIAZOLONES

    • Juan Cisneros ;
    • Pavan Kumar Reddy Gangireddy ;
    • Lanny Liebeskind ;

    FRI-508

    NOVEL DEOXYGENATION-DIMERIZATION OF BENZOISOTHIAZOLONES

    Juan Cisneros, Pavan Kumar Reddy Gangireddy, Lanny Liebeskind.

    Emory University, Atlanta, GA.

    The Liebeskind group is developing an organo-catalytic redox system to drive dehyrdative coupling chemistry. Dehydrative coupling is not only vital to biological systems but is also a very useful tool for a variety of industry sectors including energy, pharmaceuticals, and others. Our oxidation-reduction condensation reaction involves an organic oxidant, a benzoisothioazolone (BIT) and triethyl phoshite as our organic reductant. As Dr. Gangireddy first discovered, reacting these 2 in solution produces an unexpected and interesting product resulting from a deoxygenation-dimerization of the BIT. Our study focuses on the scope of this dimerization reaction with the intent of exploring its generality and optimizing the reaction conditions. Running these reactions in varying temperatures, solvents, and BIT molecules will provide a deeper understanding of the processes and help deliver a general and efficient reaction. Reactants, reaction progression, and products were analyzed and characterized using 1H, 31P, and 13C nuclear magnetic resonance spectroscopy. Further analysis was done using thin layer chromatography, infrared spectroscopy, mass spectrometry, and X-ray crystallography. Having experimented with a few BIT molecules and several different reaction conditions, the original observation of Dr. Gangireddy still stands and BIT-deoxygenation-dimerization is proving to be generalizable with substituent variance. Further study will help us to understand differences in yields and extraction difficulties and arrive at a general and informative library of BIT-deoxygenation dimers. Having a comprehensive library will then allow for the study of developing these BIT-dimers into larger complexes with possible metal coupling and a look into their c-2 symmetry and enantiocontrol running metal-catalyzed reactions.

    FRI-519 GROWTH OF NOVEL TWO-DIMENSIONAL TRANSITION METAL DICHALCOGENIDES

    • Ricardo Vidrio ;
    • Ryan Need ;
    • Stephen Wilson ;

    FRI-519

    GROWTH OF NOVEL TWO-DIMENSIONAL TRANSITION METAL DICHALCOGENIDES

    Ricardo Vidrio, Ryan Need, Stephen Wilson.

    University of California, Santa Barbara, Santa Barbara, CA.

    The introduction of graphene has resulted in a plethora of 2-dimensional electronic devices that have a variety of applications. However, graphene's metallic electrical conductivity makes it a poor substitute for semiconductors in such devices. This has led to interest in developing 2-dimensional transition metal dichalcogenides that share a similar crystal structure with graphene but exhibit semiconducting properties. In the Wilson research group, we are experimenting with methods to grow high quality, bulk single crystals of ternary dichalcogenides, such as niobium iridium telluride (NbIrTe4). These compounds have been less explored than their binary counterparts, and provide an opportunity to generate novel functionalities through appropriate cation chemistry. Crystals are grown using chemical vapor transport (CVT) in which elemental powders are sealed in an evacuated ampoule with some transporting agent and then baked in a 3-zone tube furnace for roughly 1 week. We began by tuning the relative powder amounts as well as the identity of the transport agent (i.e., iodine or bromine). Preliminary results on 9 separate batches yielded some success in producing NbIrTe4 powder, but it was not in crystalline form and it was usually formed in the presence of a number of other binary phases (e.g., IrTe2, NbTe4). More concerning was the lack of repeatability between identical samples. This suggests there is some experimental variable that plays a role in determining phase formation during the growth process. Moving forward will require additional studies to determine what variables are most important for consistently producing phase-pure batches of the ternary compound.

    FRI-525 STREPTOMYCES CLAVIFER PRODUCES ANTIBIOTICS AGAINST RESISTANT STRAINS OF STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI

    • Erick Maglalang ;
    • Luis Mota-Bravo ;

    FRI-525

    STREPTOMYCES CLAVIFER PRODUCES ANTIBIOTICS AGAINST RESISTANT STRAINS OF STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI

    Erick Maglalang, Luis Mota-Bravo.

    University of California, Irvine, Irvine, CA.

    The immergence of antibiotic resistant bacteria such as S. aureus and E. coli, is a serious and global concern because they are resistant to many commonly used antibiotics. Streptomyces clavifer have never been reported as antibiotic producers against beta-lactam resistant S. aureus and E. coli. The objectives of our research were: to analyze active antibiotics from S. clavifer against beta-lactam resistant S. aureus and E. coli and to purify the active compounds. S. clavifer was tested for antibiotic activity against sensitive S. aureus ATCC 25923 and resistant S. aureus ATCC 43300. S. clavifer was tested against susceptible and beta-lactam resistant E. coli ATCC 25922 and 35218, respectively. Each fraction was tested for purity using reverse-phase high performance liquid chromatography (RP-HPLC). The zone of inhibitions from S. clavifer against S. aureus ATCC 25923 and 43300, and E. coli ATCC 25922 and 35218 were 6.5, 8.5, 5.5, and 5.0 mm, respectively. S. clavifer produced 3 antibiotics that were effective against sensitive and, resistant S. aureus with Rf values 0.74, 0.31, and 0.27. Additionally, S. clavifer produced 2 antibiotics against sensitive and resistant E. coli with Rf values 0.74 and 0.31. The antibiotic (R= 0.31) from S. clavifer that inhibited both beta-lactam resistant S. aureus and E. coli was successfully purified. RP-HPLC-chromatogram showed one dominant peak suggesting high purity of sample. Purifying the antibiotics responsible for the activity against resistant S. aureus and E. coli, as well as identifying the structure of antibiotics are essential for future investigations.

    FRI-518 STABILITY STUDY OF LI-ION BATTERY CATHODE MATERIALS

    • Giovanni Monterroso ;
    • Chandana Meegoda ;

    FRI-518

    STABILITY STUDY OF LI-ION BATTERY CATHODE MATERIALS

    Giovanni Monterroso, Chandana Meegoda.

    Northeastern Illinois University, Chicago, IL.

    Lithium ion batteries have been successfully used by many industries such as consumer electronics and motorized vehicles and are now being used for military and aerospace applications. In spite of their widespread use, Li-ion batteries suffer from having flammable electrolyte materials that can sometimes even lead to explosions. Therefore, it is important to study the stability of these batteries. Cathode materials play an important role on the electrochemical performance of the batteries and LiFePO4 is widely used as a cathode material in view of its large theoretical capacity (170 mAhg-1). However, low electronic conductivity and ionic conduction are major drawbacks of this material. In this study, we examined the stability of LiMPO4 (M = Fe, Co, and Ni) cathode materials under different acidic, basic, and temperature conditions. FTIR spectroscopy was mainly used for the stability study and spectra shows a dominant band for the stretching and bending modes of the PO43- polyanions. We determined that both LiFePO4 and LiCoPO4 are stable even at 200 °C. Under acidic conditions LiCoPO4 seems more stable than LiFePO4. In order to better understand the stability and structure of these materials, LiMPO4 (M = Fe, Co, Ni, and Mn) was synthesized using sol gel synthesis and microwave synthesis. As compared to the sol gel method, microwave synthesis needs less time. Further experiments will be carried out to find the optimal experimental conditions to synthesize these materials.

    FRI-511 SYNTHESIS OF RHENIUM CARBONYL COMPLEXES AS PHOTOCORMS: CONTRAST IN DENTICITY DEPENDING ON THE FLEXIBILITY OF THE LIGAND

    • Jennyfer Tena ;
    • Indranil Chakraborty ;
    • Pradip Mascharak ;

    FRI-511

    SYNTHESIS OF RHENIUM CARBONYL COMPLEXES AS PHOTOCORMS: CONTRAST IN DENTICITY DEPENDING ON THE FLEXIBILITY OF THE LIGAND

    Jennyfer Tena, Indranil Chakraborty, Pradip Mascharak.

    University of California, Santa Cruz, Santa Cruz, CA.

    Although CO (carbon monoxide) has been known as the silent killer, our body naturally produces CO in small amounts during the degradation of heme by the enzyme called heme oxygenase (HO). This has prompted researchers to use CO in various therapeutic settings. However, application of CO in gaseous form suffers from difficulty in ensuring controlled and safe delivery. Therefore certain metal-carbonyl complexes have been proposed as carbon monoxide releasing molecules (CORMs), which are expected to show CO release in a more controlled manner. The major downside of CORMs is associated with sustainable delivery. Thus, the photo-induced carbon monoxide releasing molecules (photoCORMs) have emerged as credible alternatives where the CO-release process can be triggered on light illumination. In the Mascharak lab, we are interested in the synthesis of photoCORMs using suitable design principles. Herein, we have synthesized and characterized a rhenium carbonyl complex, [ReCl(CO)3(qmtpm)] incorporating a qmtpm ligand: qmtpm = 2-quinoline-N-(2’-methyltiophenyl)-methyleneimine). This complex is structurally characterized. The next step in this project is to reduce the qmtpm ligand with NaBH4 to obtain a corresponding amine (qmtpa). The main aim is to determine whether the flexibility of the qmtpa ligand (compared to qmtpm) can lead to a tridentate binding mode in contrast to the qmtpm, which shows a bidentate chelation with a -SMe appendage. All the complexes synthesized are, or will be, characterized by 1H NMR, IR, and UV-Vis spectroscopy and, wherever possible, with single crystal X-ray crystallography.

    THU-524 NOVEL STRATEGIES FOR THE EFFICIENT OXIDATION OF NADH AT A CARBON-NANOTUBE-BASED, GLUCOSE-OXIDIZING BIOANODE USING GLUCOSE DEHYDROGENASE

    • Nicolas Means ;
    • Noemie Lalaoui ;

    THU-524

    NOVEL STRATEGIES FOR THE EFFICIENT OXIDATION OF NADH AT A CARBON-NANOTUBE-BASED, GLUCOSE-OXIDIZING BIOANODE USING GLUCOSE DEHYDROGENASE

    Nicolas Means1, Noemie Lalaoui2.

    1Oklahoma State University, Stillwater, OK, 2Joseph Fourier University, Grenoble, FR.

    In a glucose-based biofuel cell, glucose and O2 are used to produce electrical energy. In these fuel cells, chemical energy is converted to electrical energy by a redox enzyme at each electrode. To harness this electrical energy, the enzyme has to be immobilized and in contact with the electrode. At the bioanode, glucose dehydrogenase (GDH) is an NAD-dependent enzyme which can be considered. To work, this enzyme needs NAD+ as a cofactor. During the oxidation of glucose, the GDH reduces NAD+ to NADH. One of the main challenges in designing a bioanode using GDH is the efficient oxidation of the cofactor at low overpotentials. Here, we report 3 ways to reoxidize NADH to NAD+ on a multiwalled carbon nanotube (MWCNT)-based electrode. MWCNTs have been particularly useful in the development of a biofuel cell electrode. They are employed because they have a high, specific surface for immobilizing a high amount of enzyme with the ability to efficiently transfer electrons between the catalyst and the electrode. These MWCNT electrodes exhibit NADH electrocatalytic oxidation properties. These electrocatalytic properties were compared with MWCNTs either functionalized with an NADH oxidation molecular catalyst or an NADH-oxidizing enzyme, diaphorase. Afterward, our electrodes were functionalized with GDH for glucose electrocatalytic oxidation. This work contributes to a promising approach for a bioanode design for enzymatic biofuel cells.

    THU-526 FABRICATING A STRUCTURALLY COLORED PHOTONIC CRYSTAL PH SENSOR

    • Esperanza Hernandez ;
    • Paige Stokes ;
    • Elijah Shirman ;
    • Katherine Phillips ;
    • Joanna Aizenberg ;

    THU-526

    FABRICATING A STRUCTURALLY COLORED PHOTONIC CRYSTAL PH SENSOR

    Esperanza Hernandez1, Paige Stokes2, Elijah Shirman3, Katherine Phillips3, Joanna Aizenberg3.

    1The University of Utah, Salt Lake City, UT, 2Arizona State University, Tempe, AZ, 3Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA.

    Colorimetric sensors are promising cheap, simple to use, accessible sensors that can have applications ranging from medicine to the environment. This summer we worked on the fabrication of a colorimetric sensor that consists of a structurally colored, photonic-crystal, pH-responsive hydrogel with a structure based on an opal template. Opals are ordered microstructures of closely packed polystyrene spheres. In our system, these spheres create pores in the hydrogel. A pH-responsive hydrogel shrinks when the pH of a solution is acidic, and expands when the solution is basic. The compression and expansion of the hydrogel causes the pores to change size. The pores in the hydrogel diffract certain wavelengths of visible light and, when they change size, there is a color shift. The opal was created from self-assembled polystyrene colloids that were assembled on a slide overnight. The opal was then infiltrated with a hydrogel precursor and exposed to UV light to cure. The compound opal was then submerged in toluene to remove the colloidal spheres from the hydrogel. The inverse opal hydrogel was analyzed using 2 solutions with pH 4 and pH 8. The results we have obtained show we have successfully created a pH-responsive hydrogel that changes color as the pH changes. Ultimately, we aim to apply our method to create similar sensors that can have applications ranging from water testing to the fast detection of infectious diseases.

    THU-506 SUPPORTING THE TRANSITION TO NAU IN STEM: TRANSFER-GEMS

    • Alexander Ollerton ;
    • Meghan Belmares ;
    • Nena Bloom ;
    • Brent Nelson ;
    • Derek Sonderegger ;
    • Jennifer Duis ;
    • Pauline Entin ;

    THU-506

    SUPPORTING THE TRANSITION TO NAU IN STEM: TRANSFER-GEMS

    Alexander Ollerton1, Meghan Belmares1, Nena Bloom2, Brent Nelson1, Derek Sonderegger1, Jennifer Duis1, Pauline Entin1.

    1Northern Arizona University, Flagstaff, AZ, 2Center for Science Teaching and Learning, Northern Arizona University, Flagstaff, AZ.

    For a number of reasons, many undergraduates decide to start school at a 2-year college while intending eventually to transfer to a 4-year institution. However, incoming freshmen are the primary target of 4-year institutions’ support, resources, and scholarships. In addition to these issues, incoming science, technology, engineering, and math (STEM) transfer students may have difficulty transferring their credits from their previous institutions and may not enter with critical introductory coursework (e.g., calculus and general chemistry) completed, which slows down degree progression. In an effort to help with these issues, a learning community and NSF-funded scholarship (Transfer-GEMS) was developed to support transfer students in the College of Engineering, Forestry, and Natural Sciences (CEFNS) at Northern Arizona University. Additional efforts include outreach to community colleges and improvement of institutional websites to provide better information to transfer students. The intent of the Transfer-GEMS program is to increase retention rate and success while trying to decrease time to graduation. Voluntary survey data and tracking of academics (e.g., GPA) before and during program implementation will allow us to better understand the CEFNS transfer student experience and examine how the transfer student experience is impacted by the Transfer-GEMS program. (This material is based on work supported by the National Science Foundation under Grant Number 1260138.)

    FRI-504 ELECTROCHEMICAL STUDY OF GROUP 6 METAL CARBONYLS FOR CO2 REDUCTION

    • Cesar Saucedo ;
    • Kyle Grice ;

    FRI-504

    ELECTROCHEMICAL STUDY OF GROUP 6 METAL CARBONYLS FOR CO2 REDUCTION

    Cesar Saucedo, Kyle Grice.

    DePaul University, Chicago, IL.

    The electrochemical responses of Mo, W, Cr, Mn, and Re carbonyls were studied in organic solvents. These complexes were studied for use in the reduction of carbon dioxide. These group 6 species showed significant responses under CO2, indicating CO2 reduction. No response was seen for Mn and Re complexes. Protic additives such as water were studied under argon and carbon dioxide gas for Mo(CO)6, W(CO)6, and Cr(CO)6. On addition of water, a proton source, the response under CO2 was reduced for the group 6 complexes. No change in response was seen for Mn and Re complexes with protic additives under CO2. Proton NMR, IR, and electrochemical methods such as cyclic voltammetry were used to gather data on the CO2 reactivity. Catalytic peaks under carbon dioxide were analyzed for the relative efficiency and potentials of the group 6 carbonyl catalysts. These species are rare examples of group 6 complexes that are electrocatalysts for CO2 reduction.

    FRI-502 IN VITRO STUDIES ON THE IMPACT OF THE LIPID COMPONENT OF NOVEL LIPOPEPTIDES ON BIOLOGICAL ACTIVITY

    • Westley Cruces ;
    • Brandi Betts-Obregon ;
    • Andrew Tsin ;
    • George R. Negrete ;

    FRI-502

    IN VITRO STUDIES ON THE IMPACT OF THE LIPID COMPONENT OF NOVEL LIPOPEPTIDES ON BIOLOGICAL ACTIVITY

    Westley Cruces, Brandi Betts-Obregon, Andrew Tsin, George R. Negrete.

    The University of Texas at San Antonio, San Antonio, TX.

    Bacterial diseases are known to affect animals, plants, and humans. A devastating bacterium that causes citrus greening has decreased Florida’s citrus production. This disease has drawn attention from the scientific community. Lipopeptides have been shown to have antibiotic properties. Our laboratory has been synthesizing novel cysteine-derived lipid analogs (CLAs) as potential antibiotics by studying the structure-activity relationships of lipopeptides against the bacteria and human adult retinal pigment epithelial cells (ARPE19). The target antibiotics share a thiazolidine core with an acryloyl group that can be coupled with alkyl or aryl thiols via conjugate addition and carboxylic acid and aryl nitro groups. The latter can be reduced to an amine so that the carboxyl and amino groups can be employed to append to peptide chains and fluorophores via peptide coupling methods. Constructs with lipid, peptide, and fluorescent labels can be employed for bioactivity, binding, and localization studies with bacterial and other cell lines. Our CLAs will be dissolved in serum-free DMEM: F12 and placed into bacteria and ARPE19 culture media at 37 oC and 5% CO2 for 24, 48, and 72 hours. After each time interval, conditioned media (CM) will be removed and cells will be harvested and counted for cell viability using the trypan blue dye exclusion method. To study CLA's binding and entry into cells, bacteria and ARPE19 cells will be fixed for Ziess 710 confocal imaging to determine the location of the CLAs.

    THU-505 DIGITAL DEVICE USE IN THE UNDERGRADUATE CHEMISTRY CLASSROOM

    • Meghan Belmares ;
    • Alexander Ollerton ;
    • Brandon Cruickshank ;
    • Jennifer Duis ;

    THU-505

    DIGITAL DEVICE USE IN THE UNDERGRADUATE CHEMISTRY CLASSROOM

    Meghan Belmares, Alexander Ollerton, Brandon Cruickshank, Jennifer Duis.

    Northern Arizona University, Flagstaff, AZ.

    Digital devices (smart phones, tablets, laptops, etc.) and their use are increasingly commonplace in colleges today, whether for personal or course-related efforts. Research has suggested that class time use of digital devices negatively affects grades, but little is known about the impact of instructors’ or students’ attempts to control the use of digital devices during class. The influence of a number of factors will be evaluated by this research including upper (physical and analytical chemistry) and lower (general and organic) level courses, instructor, syllabus policies, and classroom management styles. These factors will be used to examine differences in self-reported classroom digital device use, correlations between frequency of use and grade, and student perceptions. Current data was collected anonymously and voluntarily from students via surveys in 15 different course sections with 11 different instructors in the spring of 2015. Spring 2014 survey results did not show a negative correlation between the frequency of use and course grade despite fall-2013 work in general chemistry that had paralleled other authors’ reports. Also, a vast majority of students believe that digital device use does not impact their grade in the course. Further investigation will go into the students’ interest in the class, the seating arrangement within the classroom, and self-reported perceptions of distraction to other students.

    FRI-505 PROGRESS IN THE SYNTHESIS OF SELF-ASSEMBLING BISCAVITANDS

    • Maria Escamilla ;
    • Jeffrey Buenaflor ;
    • Linda Tunstad ;

    FRI-505

    PROGRESS IN THE SYNTHESIS OF SELF-ASSEMBLING BISCAVITANDS

    Maria Escamilla, Jeffrey Buenaflor, Linda Tunstad.

    California State University, Los Angeles, Los Angeles, CA.

    The field of supramolecular chemistry includes complex systems of assembly formed through non-covalent electrostatic interactions. Our project reports a versatile synthetic design to generate a series of polyfunctionalized biscavitands with linkers that vary in length and flexibility. Resorcin[4]arene cavitands are molecules that possess a bowl-like conformation that enables them to bind or entrap smaller compounds. We will be exploring how the flexibility of the cavitand linkers and different cavitand functional groups, such as hydroxyls and carboxylic acids, will affect the formation of either oligomers or capsules as well as shape, size, and guest complexation. Polyhydroxy and polycarboxylic acid compounds are of interest because of their ability to mimic biological interactions. The structures will be verified by nuclear magnetic resonance (NMR), infrared spectroscopy, and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). These molecules can potentially be tailored to function as biosensors, molecular switches, or toxic remediators.

    FRI-506 NUCLEOPHILE OR RADICAL TRAP: THE ROLE OF ALKENES IN THE INTRAMOLECULAR REACTIONS OF OXIME AND OXIME ETHER RADICAL CATIONS

    • Nicholas Armada ;
    • Peter de Lijser ;

    FRI-506

    NUCLEOPHILE OR RADICAL TRAP: THE ROLE OF ALKENES IN THE INTRAMOLECULAR REACTIONS OF OXIME AND OXIME ETHER RADICAL CATIONS

    Nicholas Armada, Peter de Lijser.

    California State University, Fullerton, Fullerton, CA.

    Oxidative processes often lead to the formation of reactive intermediates such as radicals and radical ions. Oxidation of oxime and oxime ethers yield iminoxyl radicals and oxime ether radical cations, which when formed in cells may cause damage to tissues and DNA. Since the reactivity of these intermediates is largely unexplored and we want to learn about the fundamental reactivity of iminoxyl radicals and oxime ether radical cations, we have begun an investigation on intramolecular reactions of oximes and oxime ethers using built-in alkenes as a potential nucleophile or radical trap. Previously, built-in alkynes and aromatic rings were explored as radical traps or nucleophiles. Alkyne compounds were found to react as radical traps because they only cyclized with the oximes, which is indicative of an iminoxyl radical intermediate. Compounds with built-in aromatic rings were found to react exclusively with the oxime ethers, which is indicative of a radical ion intermediate with the aromatic ring acting as the nucleophile. This project explores the reactivity of alkene functional groups under similar oxidative conditions. We hypothesize that the alkene may act as a nucleophile or as a radical trap to form a cyclized product. Photolysis of the substrate in the presence of a sensitizer leads to the formation of the intermediate that can cyclize. Preliminary results suggest that cyclization occurs. NMR analysis of the reaction mixture shows the presence of a new product. These results are similar to the reactions of the molecules with built-in aromatics, suggesting a similar pathway with the alkene acting as a nucleophile.

    FRI-503 DESIGN AND SYNTHESIS OF MIXED CITRATE/HYDROXYPYRIDIN-ONE CHELATORS: ANALOGS OF THE STEALTH SIDEROPHORE PETROBACTIN

    • Garrett Overcast ;
    • David Favela ;
    • Hollie Jacobs ;
    • Aravamudan Gopalan ;

    FRI-503

    DESIGN AND SYNTHESIS OF MIXED CITRATE/HYDROXYPYRIDIN-ONE CHELATORS: ANALOGS OF THE STEALTH SIDEROPHORE PETROBACTIN

    Garrett Overcast, David Favela, Hollie Jacobs, Aravamudan Gopalan.

    New Mexico State University, Las Cruces, NM.

    Petrobactin (PB) is the siderophore secreted by Bacillus anthracis to obtain iron from its host. PB relies on a citrate and two unusual 3,4-catechol moieties to achieve iron binding. It is a “stealth” siderophore because it is able to evade the human immune system; however, it is unknown how it evades the immune system. In this study, analogs of PB have been designed and synthesized. Specifically, the citrate core remains but the catechol ligands have been replaced by either 3-hydroxypyridin-2-one or 3-hydroxypyridin-4-one ligands anchored by an alkyl chain. The synthetic route to these new mixed ligand siderophores will be presented.

    THU-525 TEMPERATURE-DEPENDENT MEASUREMENTS OF CHARGE ORGANIZATION IN 1-ALKYL-3-METHYLIMIDAZOLIUM BIS(TRIFLUOROMETHYLSULFONYL) IONIC LIQUIDS OBTAINED FROM VIBRATIONAL SPECTROSCOPY

    • Lauren Thompson ;
    • Christopher M. Burba ;

    THU-525

    TEMPERATURE-DEPENDENT MEASUREMENTS OF CHARGE ORGANIZATION IN 1-ALKYL-3-METHYLIMIDAZOLIUM BIS(TRIFLUOROMETHYLSULFONYL) IONIC LIQUIDS OBTAINED FROM VIBRATIONAL SPECTROSCOPY

    Lauren Thompson, Christopher M. Burba.

    Northeastern State University, Tahlequah, OK.

    There is incentive to measure charge organization of ionic liquids to better understand the correlation between their liquid structures and their transport properties. Typical measurement techniques such as neutron scattering measurements are not easily accessible. As an attainable and cost-efficient alternative, we propose using ATR and transmission FT-IR spectroscopy to quantitatively assess the amount of charge organization. We will compare 2 independent measurements of the dipole moment derivative for a vibrational mode of the ionic liquid. The first measurement is derived from the optical constants, obtained from a Kramers-Kronig transform of ATR IR spectrum. The second measurement comes from applying dipolar coupling theory to the magnitude of the TO-LO band splitting for a vibrational mode in the infrared absorption spectrum. In applying dipolar coupling theory, we assume the ions in the ionic liquid are distributed among lattice sites of a crystal. Optimistically, the assumptions of dipolar coupling theory will be partially satisfied because the ionic liquid will adopt a disordered “quasilattice.” Since assumptions about the quasilattice are not required to estimate the dipole moment derivate from the ATR spectrum, disparities between the 2 measurements can be quantified. Through interpretation, this reveals how close the ionic liquid is to satisfying the assumption of a perfect crystalline lattice, thus quantitative assessments of charge organization can be obtained. In this work, we investigate a family of 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl) ionic liquids. We measure the temperature-dependent IR and Raman spectra of the compounds and interpret the results in light of our proposed methodology.

    THU-503 PHOSPHOPROTEIN EXPRESSION PROFILING OF TUMOR SAMPLE FOR CANCER SUB-CLASSIFICATION USING MICRORING RESONATORS

    • Ruth Londono ;
    • James Wade ;

    THU-503

    PHOSPHOPROTEIN EXPRESSION PROFILING OF TUMOR SAMPLE FOR CANCER SUB-CLASSIFICATION USING MICRORING RESONATORS

    Ruth Londono, James Wade.

    University of Illinois at Urbana-Champaign, Urbana, IL.

    Next-generation cancer treatments rely on molecular diagnostics to identify the patients that would benefit from treatment. These diagnostics are part of the larger field of personalized medicine. One branch of molecular diagnostics is the detection of phosphoproteins that drive cancer growth and proliferation. Phosphoprotein information is limited because most current methods focus on a single target. Microring resonator arrays allows for the detection and analysis of multiple phosphoproteins. In this study, microring resonators, which are silicon photonic biosensors, are applied to samples of cell lysate from cancer cell culture. Microring resonators are capable of up to 32-plex analysis. We use this multiplexing capability to detect multiple phosphoprotein targets in a single assay. This assay can analyze 12 phosphoprotein levels simultaneously in less than 2 hours. The method is capable of monitoring changes due to cell state and environmental alterations. Future implications of this study include monitoring changes in cancer cells due to treatment, differentiating and classifying cancer cells as well as cancer stages, and studying the effects of oncogenes in protein signaling.

    THU-502 THEORETICAL STUDY OF BIODEGRADABLE DISULFIDE MANGANESE(II) COMPLEXES AS POTENTIAL MRI CONTRAST AGENTS

    • Lisa Martinez ;
    • Maria Benavides ;

    THU-502

    THEORETICAL STUDY OF BIODEGRADABLE DISULFIDE MANGANESE(II) COMPLEXES AS POTENTIAL MRI CONTRAST AGENTS

    Lisa Martinez, Maria Benavides.

    University of Houston-Downtown, Houston, TX.

    Magnetic resonance imaging has become essential in clinical diagnostic imaging due to its ability to provide high contrast images of soft tissues. Currently, gadolinium (III)-based contrast agents are predominantly being used in the market. However, these contrast agents in high doses can be toxic to body tissues if leaked in the system. Non-gadolinium-based contrast agents such as disulfide manganese(II) copolymer complexes are being developed since they could potentially be a safer alternative. Two biodegradable macromolecular complexes, Mn(II)-EDTA and Mn(II)-DTPA cystamine copolymers were recently synthesized, and their contrast imaging enhancement was investigated on mice. The chemical nature of these compounds play an important role in their application as contrast agents; therefore, our computational study focuses on the determination of the structures, molecular properties, vibrational frequencies, and IR spectra of these 2 manganese(II) complexes. Our approach involves the use of density functional theory (DFT) in combination with B3YLP functional and basis sets 3-21G, 6-31G, and SDD. The highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy gap were determined with values exceeding 2 eV, suggesting that these complexes are chemically stable. The dipole moment values range between 6 to 10 Debye which indicate these complexes are polar. Our computed vibrational frequencies were compared to experimental values and were found in excellent agreement, which indicates our proposed structures are good representations of the 2 manganese(II) complexes.

    THU-504 PREPARATION OF 3-HYDROXY-PYRIDIN-2-ONE (3,2-HOPO) SULFONATE SALTS: USEFUL INTERMEDIATES FOR THE SYNTHESIS OF 3,2-HOPO TETHERED SULFONAMIDES, SULFONYL AZIDES, AND SULFONATE ESTERS.

    • Chintelle James ;
    • Tai Tai Phan ;
    • Chris Cook ;
    • Hollie Jacobs ;
    • Aravamudan Gopalan ;

    THU-504

    PREPARATION OF 3-HYDROXY-PYRIDIN-2-ONE (3,2-HOPO) SULFONATE SALTS: USEFUL INTERMEDIATES FOR THE SYNTHESIS OF 3,2-HOPO TETHERED SULFONAMIDES, SULFONYL AZIDES, AND SULFONATE ESTERS.

    Chintelle James, Tai Tai Phan, Chris Cook, Hollie Jacobs, Aravamudan Gopalan.

    New Mexico State University, Las Cruces, NM.

    Chelators carrying the 3-hydroxypyridin-2-one (3,2-HOPO) ligand have therapeutic and diagnostic appeal because of their ability to form strong complexes with hard metal ions such as iron and gadolinium. This could allow the removal of excess of iron in people suffering from Cooley’s anemia. Other compounds could also be tied to the sulfonate salt to produce a variety of ligands such as amino acids (sarcosine) that could be used for enzymatic studies. The purpose of this study is to develop a convenient tethering methodology to prepare suitable HOPO sulfonyl intermediates that can be linked to various amines, alcohols, and amino acids to generate a variety of HOPO sulfonyl ligands. A simple route for HOPO-sulfonamides and HOPO-sulfonate + sarcosine that uses sulfonyl chloride for the key coupling step has been identified. Both the strategy and efforts to improve the efficiency of the route will be presented.

    THU-501 SYNTHESIS AND STRUCTURE-ACTIVITY STUDIES OF DRUGS THAT AFFECT A CANCER-CAUSING MECHANISM AND REDUCE CELL GROWTH

    • Aneta Jelowicki ;
    • Peter de Lijser ;

    THU-501

    SYNTHESIS AND STRUCTURE-ACTIVITY STUDIES OF DRUGS THAT AFFECT A CANCER-CAUSING MECHANISM AND REDUCE CELL GROWTH

    Aneta Jelowicki, Peter de Lijser.

    California State University, Fullerton, Fullerton, CA.

    A survey of data obtained from a variety of biological assays on a drug library consisting of more than 200 synthesized small organic molecules has revealed significant potential anticancer activity for molecules containing a specific structural motif. Previously, several of the compounds in a library of drugs, which were designed to activate the Wnt pathway to promote stem cell pluripotency, were found to decrease the β-catenin levels in the cell. The dysregulation of β-catenin has also been linked to various types of cancer, and we therefore decided to investigate the potential influence of these drugs on cell proliferation. The drugs tested in the assays consisted of compounds containing chalcones, amines, amides, small peptides, esters, aldehydes, and ketones as well as oximes and oxime-ether functionalities. Cell proliferation was determined by the CyQuant assay, which uses the DNA content of the cells to quantify the number of plated cells. HeLa cells were treated with the drug (10 μM) for 24 hours, and the DNA content was quantified. Preliminary results show that several drugs inhibit cell proliferation significantly, in some cases even better than known anticancer drugs such as mitomycin C and cisplatin. Further studies are currently under way to determine the mechanism of action underlying the antiproliferative effect of these drugs. A structure-activity analysis of the most active drugs suggests that many of them have an amide linker as a common functionality. Further work is under way to expand the drug library in order to find more drugs possessing these properties.

    THU-500 QUANTIFYING POLYCYCLIC AROMATIC HYDROCARBONS IN PARTICULATE MATTER FOR STUDENT TRAINING

    • Antonio Garcia IV ;
    • Krishna Foster ;

    THU-500

    QUANTIFYING POLYCYCLIC AROMATIC HYDROCARBONS IN PARTICULATE MATTER FOR STUDENT TRAINING

    Antonio Garcia IV, Krishna Foster.

    California State University, Los Angeles, Los Angeles, CA.

    Polycyclic aromatic hydrocarbons (PAHs) are comprised of 3 or more fused benzene rings that are formed through incomplete combustion processes. PAHs are known to have adverse effects on the environment and human health and, due to this concern, students should have the opportunity to assess air quality and enrich their knowledge of atmospheric chemistry. The use of low-volume vacuums is one method to sample PAHs; however; these types of equipment are not as accessible to students due to their high costs. Static particulate matter (SPAM) sampling systems are a possible low cost alternative that students can use for sampling PAHs. The objective of this research is to develop a reproducible and accurate method incorporating the SPAM sampling system that can be used to sample and detect PAHs in the atmosphere. Samples were collected in the Los Angeles Basin using the SPAM sampling system. PAHs were extracted using an accelerated solvent extractor and analyzed using high performance liquid chromatography with tandem fluorescence and ultra-violet visible detectors. Standardized samples of PAHs were analyzed to produce a calibration curve and obtain retention times for the given PAHs. For the analyzed samples, 12 PAHs were confirmed to be present within the limits of detection calculated.

    FRI-501 GEL-ENCAPSULATED NANOPARTICLES AND THEIR ARSENIC-REMOVAL PROPERTIES

    • David Ramirez ;
    • Juan Noveron ;

    FRI-501

    GEL-ENCAPSULATED NANOPARTICLES AND THEIR ARSENIC-REMOVAL PROPERTIES

    David Ramirez, Juan Noveron.

    The University of Texas at El Paso, El Paso, TX.

    Arsenic (As) is an element that occurs in 200 different natural mineral forms such as arsenates, sulphides, sulfosalts, arsenides, and arsenites, but most concerning are the 2 forms that are found in significant quantities in natural waters: arsenite (AsO33-) and arsenate (AsO43-). They are toxic to both plants and animals due to their similarity to the analogous phosphite and phosphate, respectively. Current methods for arsenic removal from water rely on iron hydroxide dust that adsorbs the oxo ions, but this process is inefficient and requires large quantities of iron and can only be done in large-scale facilities. New materials that remove arsenate from water and can pave the way to decentralized water treatment technologies are warranted. Our research focuses on developing nanoparticles trapped within hydrogels that uptake arsenate on their high surface area. We have synthesized a copolymer gel that tightly binds transition metal ions and on redox reactions forms nanoparticles with a wide variety of chemical compositions. We will present the synthesis and characterization of gel-encapsulated nanoparticles with [M(II)(O)x(OH)y]n composition, in which M (first-row transition metal), x, y, and n are systematically varied. Their arsenate-removal properties, measured with ICP, will be presented.