Aspirin is a common over-the-counter drug used to treat pain, fever, and inflammation. It is one of the most widely used medications in the world with an estimated 35,000 metric tons produced and consumed annually. Recent research has shown that the regular ingestion of aspirin reduces a person's risk of developing colon cancer and even promotes colorectal tumor regression. Moreover, aspirin has a demonstrated ability to inhibit the proliferation of colorectal cancer cells in vitro. Although the mechanism of action has not yet been unequivocally established, it is clear that the synthesis of novel aspirin analogs is of medicinal interest. In this study, a library of aspirin analogs of varying degrees of hydrophobicity and steric hindrance were synthesized using salicylic acid as the molecular scaffold and a variety of acyl chlorides. These aspirin analogs will be screened against an array of cancer cell lines and will also be evaluated as antibacterial agents to determine their medicinal activity. The medicinal testing of this library of aspirin analogs will help to establish new structure-activiry relationships.
Determination of the Composition, Antioxidant Capacity, and Antiproliferative Activity of Black Walnut (Juglans Nigra) Husk Extracts. Marissa Bradley, Lawrence Technological University; Jonathan Wenzel, Michelle Ammerman, Cheryl Samaniego, Lihua Wang, Eli Ward, and Elizabeth Milanov, Kettering University
The black walnut (juglans, nigra) tree is valued for its wood and edible kernels. Although walnut husks contain phenolic compounds with potential for medical applications, they are discarded during food processing. A small-scale supercritical reactor was built to extract compounds from black walnut husks. The purpose of this research was to determine the effects of drying walnut husks before extraction on the antioxidant content, compounds present, and antiproliferative potential of the extracts. Extractions were performed using supercritical carbon dioxide with an ethanol modifier. Total phenolic content assays were used to compare antioxidant activity and high-performance liquid chromatography-mass spectrometry (HPLC-MS) was used to determine the phenolic compounds present. The antiproliferative abilities of the extracts were assessed in alamarBlue[R] assays using SKBR-3 (human breast cancer) cells. The antioxidant and antiproliferative properties of the supercritical extracts were compared with additional extractions performed using ultrasonic extraction. The walnut husk samples which were not dried prior to extraction showed greater antioxidant capacity than the dried samples. The different pretreatment methods resulted in different relative concentrations of the phenolic compounds identified. HPLC-MS analysis indicated two major components of the extracts were likely quercetin-rhamnoside and quercetin-galactoside. The extracts showed antiproliferative properties against SKBR-3 cells.
Determining the Activation Energy for a Salt, Water, and Alcohol Emulsion. Ashlee Bartlett and Michael Nydegger, Spring Arbor University
Emulsions are formed when substances of different polarities and densities are mixed or agitated and are stabilized by emulsifiers. Emulsions are found in the cosmetic and food industries as well as in oil recovery operations. When left undisturbed, emulsions eventually demulsify leaving the more dense substance to rest at the bottom and the less dense solution rising to the top. Demulsification occurs as a result of the polarity and density differences of the substances that make up the emulsified solution, one being more polar and the other being less or non-polar. The demulsification process of a solution is dependent upon the temperature of the emulsion--those at higher temperatures demulsify quicker. After an emulsion composed of NaCl, [H.sub.2]0, and isopropyl alcohol was synthesized, the temperature of the emulsion was varied and the duration of demulsification was recorded. Using the rate law and Arrhenius equations a plot of the natural log of the rate vs. the inverse of temperature was generated, which yielded a linear regression. The slope of the line produced the energy of activation, EA, for the demulsification process.
Using Correction Factors to Improve Theoretical Enthalpy of Combustion Calculations for Hydrocarbons. Alexis R. Downing and James W. Mazzuca, Alma College
The enthalpy of combustion for a particular chemical compound is defined as the amount of heat that is released when burning one mole of that compound in oxygen. It is useful for a variety of reasons to be able to calculate this property using purely theoretical methods. Unfortunately, some methods are much more computationally demanding than others. As an example, MP2 calculations typically produce very accurate results, but at the expense of computational time. These high-level computations may not be accessible to laboratories with more modest computational hardware/software. In this study, we investigate whether or not it is possible to correct computationally cheaper methods based on the average error they produce for a library of organic compounds. Our initial findings, after analyzing a library of 31 different organic compounds across 7 computational methods, have shown that a simple correction factor, applied after the calculation, can reliably improve the accuracy of several relatively cheap methods, almost to the level of the very expensive MP2 calculations. We are currently testing the performance of our correction factors on a set of randomly selected organic compounds to determine both their versatility and potential application to a wide range of other organic compounds.
A Simple Way to Identify Illicit Drugs. Tammy Leong and Getahun Merga, Andrews University; Tracy Cleary and Marya Lieberman, University of Notre Dame
For many years, finding an efficient and cost-effective method of identifying illicit drugs has been an issue. Currently, the most common methods of identifying drugs are either on-site drug tests or by mass spectrometry. However, these methods have many limitations such as cost, time for each test and the need for trained personnel.
Thus, a paper analytical device (idPAD) has been developed by Dr. Marya Lieberman at the University of Notre Dame to identify illicit drugs both efficiently and inexpensively. The test may be done anywhere where water is available. It does not require power, chemical solvents or any expensive instruments and can be deployed rapidly wherever there is a drug problem.
The palm-sized idPAD consists of twelve lanes, each containing a different chemical compound which detects common functional groups found on illicit drugs. Each drug would have its own individual pattern on the PAD, which can then be analyzed and identified.
Heat Gun Synthesis of Tetracyclone Derivatives. Bruce W. Baldwin, Spring Arbor University
Tetracyclone compounds are a popular synthetic target in undergraduate organic chemistry curricula because they crystallize easily and produce brightly colored solutions. This presentation will explore the synthesis of derivative tetracyclone molecules that vary in phenyl substitution and color. In addition to exploring exciting variations in color, these reacrions are heated with a heat gun. Heat guns are normally relegated to evaporating solvent from a TLC plate and developing reactions with visualizing reagents like phosphomolybdic acid or anisaldehyde. In this reaction set, the simple jet of hot air allows students to quickly and controllably heat their reaction. The simple heating method and easily synthesized range of colored solids makes this a potentially beautiful addition of experiments to our undergraduate laboratory curriculum.
Acetylation of Hydroxymethylbenzoates. Kasey Bunker and Bruce Baldwin, Spring Arbor University
Acetylating phenols from acid anhydrides can be achieved using imidazole as a catalyst. This reaction is further catalyzed by a heat gun for greater control of the heat source. Three positional isomers of acetylated hydroxymethylbenzoate will be made and analyzed.
Modified Isoxazoline Rings for the Treatment of Malaria. Carolyn Goyne, Andrews University
With a range of actual and potential biological applications, the isoxazoline ring moity is an attractive target. As a scaffold that mimics a range of natural moieties, isoxazolines exhibit potential antibacterial, antitubercular, and a host of other properties. We are specifically interested to synthesize isoxazoline derivatives as potential inhibitors of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) enzyme in the Plasmodium falciparum parasite. The target isoxazoline contains a 3-bromo functionality that serves to aid in inactivation of the GAPDH enzyme. The first step in this synthesis is the 2+3 cycloaddition of 1,1-dibromoformaldoxime across the alkene of an allyl acetate. Further reactions will afford the product isoxazoline derivatives for testing against the malaria enzyme target where a large variability in reactions rates could be studied.
HPLC Analysis of Amino Acids in Glaucous-Winged Gull Eggshells. Alexandria Edge and Lisa Ahlberg, Andrews University
We are working to develop a reliable method of analyzing amino acid contents of Glaucous-winged Gull eggshells with High-Pressure Liquid Chromatography (HPLC). The closed-system nature of eggshells ensures that the shells' inter- and intra-molecular amino acids are highly unaffected by typical environmental stress, allowing for accurate analysis. The method of analysis requires four steps--a dissolution process, a derivatization procedure, an HPLC running method, and a between-methods cleaning routine. The amino acids are dissolved in low-concentration hydrochloric acid. They are then derivatized as part of the instrument method with o-phthaldialdehyde (OPA) and N-isobutyryl-L-cysteine (1BLC) to add fluorescence capability and improve D- and L- isomer separation. The derivatized amino acid solution can then be run through the HPLC (column: Poroshell 120 EC-C18) with a low pH buffer and methanol solvent mixture and analyzed with fluorescence spectroscopy. This amino acid quantification can be used for further analysis, such as racemization dating.
Cu(II) Complexes Catalyzed the Formation of Urea from C[O.sub.2] and N[H.sub.3] in Water. Donovan Dennis, Meng Zhou, Danielle Hanson, Xinrui Zhou, Erik Washburn, and Merve Ekmekci, Lawrence Technological University
The industrial production of urea fertilizer from C[O.sub.2] and N[H.sub.3] utilizes the highest amount of C[O.sub.2] for fertilizer production. One hundred fifty million tons of urea are produced annually, which uses more than 110 million tons of C[O.sub.2]. However, high temperature and pressure (up to 190[degrees]C and 200 atm) are required. We developed catalysts to facilitate the synthesis of urea from C[O.sub.2] greenhouse gas.
We found that solid CuO catalyzed urea formation in an aqueous solution, at 120[degrees]C and in 15 hours. Powder X-ray and proton NMR analyses showed that urea formed in up to 33% yield with 33 turnovers. Under the reaction conditions, solid CuO transformed and became soluble in water, in which a molecular Cu(II)-ammine complex likely formed. This complex has been characterized by UV-vis spectroscopy and mass spectrometry. Several Cu(II) complexes were studied as homogeneous catalysts to improve yield and selectivity. For example, 16% yield of urea formed in the presence of Cu[(N[H.sub.3)].sub.4]S[O.sub.4] catalyst, but no urea was detected (< 3%) under identical conditions in the absence of a catalyst.
Copper(II)-Catalyzed Synthesis of Urea from Carbon Dioxide and Ammonia. Erik Washburn and Meng Zhou, Lawrence Technological University
Urea is a compound commonly used in fertilizers. It is found naturally in urine and can be synthesized from C[O.sub.2] and N[H.sub.3]. However, the reaction has a significant barrier to entry, requiring a great deal of heat, pressure, and time, with a low yield of urea. The use of a catalyst can significantly reduce the energy barrier for this reaction, while increasing yield. We originally used copper(II) oxide (CuO) and Cu powder as catalysts, but theorized that during the reaction a tetraamminecopper(II) complex is formed and acts as the true catalyst. To test this theory, we synthesized four different nitrogen-ligated, mononuclear, tetrahedral copper(II)-based complexes as catalysts for the synthesis of urea: [Cu[([N[H.sub.3]]).sub.4]]S[O.sub.4]; [Cu(bipy)[Cl.sub.2]]; [Cu(Phen)[Cl.sub.2]]; and [Cu(bipy)[(C[H.sub.3]COO).sub.2]]. What we found is that urea yield increased from 9% in an uncatalyzed reaction, to as much as 33% in the presence of a catalyst.
Intrinsic Fluorescence Quantum Yield of PAMAM Dendrimers. Ryan T. Hayes, Ansel Nam, and Anthony Miller, Andrews University
Despite their lack of conjugation, polyamidoamine (PAMAM) dendrimers emit a blue fluorescence in aqueous solutions. This intrinsic fluorescence has been reported in literature, but the nature and efficiency of this emission remains to be fully explained and quantified. Previous reports show G4-PAMAM-amine dendrimer fluorescence increases in increasingly acidic solutions and larger dendrimers. This current project evaluated the fluorescence of PAMAM dendrimers with a variety of polar surface groups, sizes, and solution pHs. We report on the characteristic features of dendrimer excitation and emission spectra along with a fluorescent quantum yield obtained by comparison to the well characterized fluorescein emission. Our initial results demonstrate that the PAMAM dendrimer's fluorescence is quite weak in comparison to fluorescein, but PAMAM dendrimers experience limited quenching even at very high dendrimer concentrations. PAMAM dendrimers' intrinsic fluorescence provides a unique opportunity to track their location in biological procedures, such as transfection and drug delivery, without attaching additional chromophores. Understanding and manipulating this fluorescence could provide the knowledge for developing a colorful range of novel, nanosized imaging agents for in vitro assays.
Chemistry as Represented in the Imagery of Postage Stamps. Pasquale Di Raddo, Ferris State University
The hobby of postage stamp collecting (philately) has historically been both edifying and esthetically pleasing to the collector. In this presentation the author will present stamps, national and international in origin, which have been used to commemorate major chemical events, represent chemical structures and acknowledge leading chemists who have been responsible for landmark advances in the field. Such stamps may be used in classroom settings to enrich one's chemistry lectures.
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|Title Annotation:||drug synthesis, black walnut, emulsion's activation energy|
|Date:||Sep 22, 2018|
|Previous Article:||Botany & Plant Ecology.|