Chemistry Commons^™

Synthesis And Antimicrobial Activities Of Some Bridged Bis-Benzimidazole Derivatives, Hasan Küçükbay, Ülkü Yilmaz, Ni̇hat Şi̇reci̇, Ayşe Ni̇lay Güvenç

Turkish Journal of Chemistry

Some bis-benzimidazoles derivatives bearing allyl, crotyl, cinammyl, furfuryl, and thenyl groups were synthesized and their in vitro antimicrobial activity determined against gram-positive and gram-negative bacteria, and fungi by disk-diffusion method. The structures of all new compounds were identified by ^1H-NMR, ^{13}C-NMR, and FT-IR spectroscopic techniques and elemental analysis. All the compounds synthesized in this work were examined for their in vitro antimicrobial activities against gram-positive (Staphylococcus aureus and Bacillus megaterium) and gram-negative bacteria (Klebsiella pneumoniae and Escherichia coli), and the yeasts like fungi (Candida globrata and Candida tropicalis). Compared to the reference substances, Cefozine and nystatin, most of the compounds …

Simultaneous Determination Of Dopamine, Uric Acid, And Folic Acid By A Modified Tio_2 Nanoparticles Carbon Paste Electrode, Mohammad Mazloum Ardakani, Mohammad Ali Sheikhmohseni, Hadi Beitollahi, Ali Benvidi, Hossein Naeimi

Turkish Journal of Chemistry

The electrochemical behavior of dopamine (DA) was studied at the surface of a 2,2-[1,2 buthanediylbis(nit- riloethylidyne)]-bis-hydroquinone/TiO_2 nanoparticles modified carbon paste electrode (BQTMCPE) in aqueous media using voltammetric and chronoamperometric techniques. It was found that under optimum conditions (pH 8.0), the oxidation of DA at the surface of such an electrode occurred at about 220 mV lower than that of an unmodified carbon paste electrode (CPE). Using differential pulse voltammetry (DPV), a highly selective and simultaneous determination of DA, uric acid (UA), and folic acid (FA) was explored at the modified electrode. DPV peak currents of DA, UA, and FA increased …

Kinetic Spectrophotometric Determination Of Trace Copper(Ii) Ions By Their Catalytic Effect On The Reduction Of Brilliant Cresyl Blue By Ascorbic Acid, Hali̇l İbrahi̇m Ulusoy, Ramazan Gürkan, Mehmet Akçay

Turkish Journal of Chemistry

In the present study, a novel catalytic-kinetic spectrophotometric method was developed for the determination of trace amounts of copper. It is based on the catalytic effect of Cu(II) on the reduction of brilliant cresyl blue (BCB) by ascorbic acid in pH 5.0 acetate buffer medium. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of BCB at 624 nm. The operating conditions regarding concentration of reagents, pH, time, and temperature were established and optimized in detail. The working curve was linear in the concentration range of 0.1-5.0 \mu g L^{-1}. The maximum percentage error and standard deviation for …

Solidified Floating Organic Drop Microextraction And Spectrophotometric Determination Of Vanadium In Water Samples, Shayessteh Dadfarnia, Ali Mohammad Haji Shabani, Akram Mirshamsi

Turkish Journal of Chemistry

Solidified floating organic drop microextraction (SFODME) was used as a sample preparation method prior to spectrophotometric determination of trace amounts of vanadium in water samples. 8-Hydroxyquinoline (oxine) was used as the chelating agent. The main parameters affecting the performance of SFODME, such as pH, concentration of oxine, extraction time, sample and organic phase volume, extraction temperature, and the nature of the organic solvent, were optimized. Under the optimized conditions, an enhancement factor of 38, detection limit of 0.97 \mu g L^{-1}, and good relative standard deviation of \pm 3.9% at 10 \mu g L^{-1} were obtained. The method was successfully …

Constituents Of Plantago Major Subsp. Intermedia With Antioxidant And Anticholinesterase Capacities, Ufuk Kolak, Mehmet Boğa, Emi̇ne Akalin Uruşak, Ayhan Ulubelen

Turkish Journal of Chemistry

The methanol extract of Plantago major subsp. intermedia (Gilib.) Lange afforded 4 known compounds, namely isomartynoside (1), 10-hydroxymajoroside (2), \beta -sitosterol (3), and ursolic acid (4). Their structures were established by spectroscopic methods. After determination of the total phenolic and flavonoid contents of the methanol extract, the antioxidant potentials of the crude extract and isolated compounds 1-4 were determined by \beta -carotene bleaching, DPPH free radical and ABTS cation radical scavenging, and cupric reducing antioxidant capacity methods. The methanol extract, rich in phenolic contents, indicated the same DPPH free radical scavenging activity (72\% inhibition) as a standard compound, butylated hydroxytoluene, …

Chemistry Of Dibenzobarallene, Moustafa A. Gouda, Moged A. Berghot, Khaled M. Elattar, Abd El Galil M. Khalil

Turkish Journal of Chemistry

This review represents a systematic and comprehensive survey of the methods of syntheses and chemical reactivity of dibenzobarallene. This compound is an important intermediate for the synthesis of useful and novel heterocycle systems.

Electrocatalytic Oxidation Of Methanol At Pd And Pt Ad-Layer Modified Au(111) Electrodes In Alkaline Solution, Süleyman Koçak, Zekerya Dursun, Fatma Ni̇l Ertaş

Turkish Journal of Chemistry

The electrochemical oxidation of methanol was investigated by using various ad-layer modified Au(111) electrodes in alkaline media in comparison to Au(111), polycrystalline Pd, and polycrystalline Pt electrodes. Catalytic activity of gold toward methanol oxidation has tended to increase in more alkaline media, as reflected in the oxidation peak in the concentration range of NaOH (0.1-3.0 M) studied here. The oxidation peak potential of methanol shifted to more negative potentials, indicating a pH-dependent surface reaction. Among the electrodes studied, single-crystal gold electrode surfaces modified with Pd and Pt ad-layers displayed the highest catalytic activity for methanol oxidation. Additional shifts of about …

Synthesis Of Starch-G-Poly(Acrylic Acid-Co-2-Hydroxy Ethyl Methacrylate) As A Potential Ph-Sensitive Hydrogel-Based Drug Delivery System, Mohammad Sadeghi

Turkish Journal of Chemistry

The present work focused on the design of a drug delivery system (DDS) based on pH-sensitive hydrogel. The hydrogels were prepared via graft copolymerization of mixtures of acrylic acid (AA) and 2-hydroxy ethyl methacrylate (HEMA) onto starch backbones by a free radical polymerization technique. Sodium bicarbonate (NaHCO_3) was added to function as a foaming agent under acidic conditions, rendering the hydrogels to be porous. The porous structure of the hydrogel was essential in this system to yield a large surface area so that 5-fluorouracil (5-FU) release could be facilitated. The hydrogel, thus prepared, possessed a porous structure as determined by …

Electrochemical Impedance Spectroscopy Study On Intercalation And Anomalous Diffusion Of Alcl_4^- Ions Into Graphite In Basic Molten Salt, Ali Ehsani, Mohammad Ghasem Mahjani, Majid Jafarian

Turkish Journal of Chemistry

Electrochemical impedance spectroscopy (EIS) was employed to investigate diffusion of AlCl_4^- ions in basic (AlCl_3-NaCl-KCl) molten salt. Nyquist plots in different DC offset potentials showed finite and restricted aluminum ion diffusion due to insertion and blocking in the graphite electrode. The general Warburg, open Warburg, and short Warburg impedance in the complex Nyquist plot of this system showed the anomalous diffusion behavior of the ions in the graphite electrode. The diffusion coefficient of the AlCl_4^- ions was calculated from the slope of the Warburg line in a totally blocking film in the graphite electrode and was found to be 2.8 …

Studies On The Mechanism Of Phosphazene Ring-Opening Polymerization (Rop), Selen Bi̇lge

Turkish Journal of Chemistry

In this study, the ring-opening polymerization (ROP) of cyclic trimer N_3P_3Cl_6 catalyzed by [Et_3Si(N_3 P_3Cl_6)][CHB_{11}H_5Br_6] (3) obtained from the reaction of N_3P_3Cl_6 (1) and Et_3Si(CHB_{11}H_5Br_6) (2) at room temperature was investigated. This provided a unique opportunity to explore the polymerization mechanism. The coordinatively unsaturated cation [N_3P_3Cl_5]^+ is responsible for the ROP of N_3P_3Cl_6, and is formed by the intramolecular elimination of Et_3SiCl from 3. The detection of Et_3SiCl by ^1H-NMR as the catalysis proceeded offers new evidence for the formation of [N_3P_3Cl_5]^+. The progress of the catalysis was followed using ^{31} P-NMR and revealed the build-up of a polymer. Cyclic …

Synthesis And Characterization Of A New Methacrylic Glycomonomer, Liliana Marinela Stefan, Ana Maria Pana, Mihai Cosmin Pascariu, Eugen Sisu, Geza Bandur, Lucian Mircea Rusnac

Turkish Journal of Chemistry

The carbohydrate containing monomer 3-O-(2'-hydroxy-3'- methacryloyloxypropyl)-1,2:5,6-di-O-isopropylidene-\alpha -D-glucofuranose was easily prepared from D-glucose and methacrylic acid in 4 steps. The structure of the new methacrylic monomer was confirmed using FTIR, NMR (including ^1H-NMR, ^{13}C-NMR, COSY, HMQC and HMBC), and HPLC-MS. This work is part of our group's effort to obtain new polymers based on renewable resources with enhanced biodegradability and biocompatibility.

Preparation And Characterization Of A Series Of Thiourea Derivatives As Phase Change Materials For Thermal Energy Storage, Cemi̇l Alkan, Yusuf Tek, Derya Kahraman

Turkish Journal of Chemistry

A series of solid-liquid phase change materials, thiourea derivatives, were prepared via condensation of thiourea with the respective carboxyl chlorides (lauroyl chloride, myristoyl chloride, and palmitoyl chloride) and were then characterized by using FT-IR, ^1H-NMR, differential scanning calorimetry (DSC), and thermogravimetric (TG) analysis. The thiourea derivatives (1,3-didodecanoyl thiourea, 1,3-ditetradecanoyl thiourea, and 1,3-dihexadecanoyl thiourea) were structurally symmetric and had long alkyl groups to crystallize. Thermal analysis by DSC and spectroscopic investigation by FT-IR spectroscopy were performed on the samples before and after thermal cycling tests to determine thermal reliability. The maximum latent heats of melting and freezing of the thiourea derivatives …

Remediation Of Various Naturally Oxygenated Volatile Organic Compounds (O-Vocs) By Mn- And Cr-Supported \Gamma -Al_2o_3 Nanocatalysts, Dariush Salari, Aligholi Niaei, Seyed Ali Hosseini, Reza Leshzadeh, Hosein Afshary

Turkish Journal of Chemistry

The catalytic combustions of different naturally oxygenated volatile organic compounds (ethyl acetate, isopropanol, methyl ethyl ketone (MEK), and benzyl alcohol) alone and in binary mixtures were investigated over pure \gamma -Al_2O_3, Mn/\gamma -Al_2O_3, and Cr/\gamma -Al_2O_3. The catalysts were prepared by the wet impregnation method and were characterized using XRD, ICP-AES, SEM, and BET. Mn/\gamma -Al_2O_3 showed higher activity than others in combustion of the O-VOCs, whereas complete conversion of isopropanol (the most reactive O-VOC) occurred at 350 °C and 400 °C on Mn/\gamma -Al_2O_3 and Cr/\gamma -Al_2O_3, respectively. The following order was found for reactivity of organic compounds in …

Polyphenolic Compounds From Geranium Purpureum Vill. Growing In Turkey, Di̇dem Şöhretoğlu, Mahmut Koray Sakar, Olov Sterner

Turkish Journal of Chemistry

Two new flavonol derivatives, Geranioside A (kaempferol 3-[3-(\alpha-rhamnopyranosyl)-4-oxy-5-hydroxy-6-methyl-3,4-dihyropyran-2H- 2-pyranoside]) (1) and Geranioside B (quercetin 3-[3-(\alpha-rhamnopyranosyl)- 4-oxy-5-hydroxy-6-methyl-3,4-dihyropyran-2H-2-pyranoside]) (2), along with 5 known flavonols (quercetin (3), kaempferol (4), quercetin 4'-O-\beta -glucopyranoside (5), quercetin 3-O-\beta -glucopyranoside (6), and kaemferol-3-O-\beta -glucopyranoside (7)), a gallic acid derivative (methyl gallate (8)), and a hydrolysable tannin (pusilagin (9)), were isolated from the aerial parts of Geranium purpureum. The structures of the isolated compounds were elucidated on the basis of UV, IR, and 1D- and 2D-NMR experiments as well as TOF-MS.

Highly Functionalized Pd(0)-Catalyzed Trimethylenemethane (Tmm) Cycloadditions, Samantha Cassell

Symposium on Research and Creative Expression (SORCE)

Trimethylenemethane (TMM) cycloaddition is a palladium(0)-catalyzed process by which five-membered carbon rings are formed. This process, though very useful, results in the loss of a reactive functional group, making further synthetic steps more difficult. In order to maintain the functional group, a new, highly-functionalized TMM cycloaddition was attempted with an epoxide precursor rather than the typical acetoxy group. This precursor, trimethyl(2-oxiranyl-2-propenyl)silane, was successfully synthesized in three steps from propargyl alcohol. The epoxide was then used in a palladium(0)-catalyzed TMM cycloaddition to result in the desired cyclopentane molecule, which retained the useful oxygen and trimethylsilyl group.

Trace Metal Dispersion In Soil From Auto-Mechanic Village To Urban Residential Areas In Owerri, Nigeria, Michael A. Nwachukwu, Huan Feng, Jude Alinnor

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Due to poor waste management in mechanic villages (MVs), average metal concentration (mgkg-1) is Pb 1162±572; Mn 864±531; Cu 385±202; Fe 49259±4770; Cd 20±13; Zn 824±190; and Ni 40±35, causing ecological and public health risks in parts of Nigeria. Average metal dispersion (mgkg-1/m) from MVs to residential areas was estimated at 9.2 for Pb; 6.7 for Mn; 6.1 for Zn; 1.5 for Cu; 197 for Fe; 0.3 for Ni; and 0.04 for Cd. This represents a mobility order of Fe>Pb>Mn>Zn>Cu>Ni>Cd, and a pollution order of Pb>Ni>Mn>Zn>Fe>Cu>Cd. MV advantages …

Analysis Of Gaba And Glutamate In The Mouse Dorsal Striatum, Stella Wisidagamage

Wayne State University Theses

ABSTRACT

ANALYSIS OF GABA AND GLUTAMATE IN MICE BRAIN

by

STELLA WISIDAGAMA

May 2011

Advisor: Dr. Tiffany Mathews

Major: Chemistry (Analytical)

Degree: Master of Science

GABA and glutamate are the predominant inhibitory and excitatory amino acid neurotransmitters in the central nervous system (CNS), respectively. However, their altered levels cause several neurological diseases including Parkinson's and Huntington's disease, schizophrenia, and epilepsy. It is important to measure their levels in the extra- and intracellular environments to better understand and develop improved therapeutics that will treat these neurological disorders. The principle aim of this study is to study the impacts of different endogenous …

A Study Of Mo(4+)Quinoxalyl-Dithiolenes As Models For The Non-Innocent Pyranopterin In The Molybdenum Cofactor, Kelly G. Matz, Regina P. Mte, Rebecca Rothstein, Martin L. Kirk, Sharon J. Nieter Burgmayer

Chemistry Faculty Research and Scholarship

A model system for the molybdenum cofactor has been developed that illustrates the noninnocent behavior of an N-heterocycle appended to a dithiolene chelate on molybdenum. The pyranopterin of the molybdenum cofactor is modeled by a quinoxalyldithiolene ligand (S(2)BMOQO) formed from the reaction of molybdenum tetrasulfide and quinoxalylalkyne. The resulting complexes TEA[Tp*MoX(S(2)BMOQO)] [1, X = S; 3, X = O; TEA = tetraethylammonium; Tp* = hydrotris(3,5-dimethylpyrazolyl)borate] undergo a dehydration-driven intramolecular cyclization within quinoxalyldithiolene, forming Tp*MoX(pyrrolo-S(2)BMOQO) (2, X = S; 4, X = O). 4 can be oxidized by one electron to produce the molybdenum(5+) complex 5. In a preliminary report of …

Quality Characteristics Of Virgin Coconut Oil:Comparisons With Refined Coconut Oil, Fabian M. Dayrit, Ian Ken D. Dimzon, Melodina F. Valde, Jaclyn Elizabeth R. Santos, Mark Joseph Garrovillas, Blanca J. Villarino

Chemistry Faculty Publications

Virgin coconut oil (VCO) is a vegetable oil that is extracted from fresh coconut meat and is processed using only physical and other natural means. VCO was compared to refined, bleached, and deodorized coconut oil (RCO) using standard quality parameters, 31 P nuclear magnetic resonance (NMR) spectroscopy, and headspace solid-phase micro - extraction/gas chromatography mass spectrometry (SPME/GCMS). VCO tends to have higher free fatty acids (FFAs), moisture, and volatile matter and lower peroxide value than RCO. However, the range of values overlap and no single standard parameter alone can be 31 used to differentiate VCO from RCO. Using 31P NMR, …

Application Of Niobium Enriched Ormosils As Thermally Stable Coatings For Aerospace Aluminium Coatings, P.C. Rajath Varma, Mohamed Oubaha, Pradeepan Periyat, Colette Mcdonagh, Brendan Duffy

Articles

The aim of this experimental research is to study the ability of niobium rich sol-gel coatings to withstand thermal stress, while remaining impermeable to corrosive agents for the protection of aerospace alloys. The coating material is developed via polymeric sol-gel synthesis employing 3-(trimethoxysilyl)propylmethacrylate (MAPTMS) and niobium ethoxide precursors as a source of silicon and niobium, respectively. The beneficial effect of niobium inclusion within coating was characterised spectroscopically, calorimetrically and electrochemically. The thermal cycling effects of the coating were studied using microscopic and accelerated test methods. Electrochemical tests showed that corrosion current of the material was 2 orders lower in magnitude …

Crystallisation And Phase Transition Characteristics Of Sol-Gel-Synthesized Zinc Titanates, Suresh Pillai, Michael Seery, Nicholas Nolan

Articles

No abstract provided.

Mechanisms Of Adsorption Of Copper And Silver Ions On Carbon Materials In An Open Circuit, Mikhail M. Goldin

Faculty Publications and Presentations

No abstract provided.

Effective Numbers Of Electrons As A Criterion Of Carbon Suitability As A Hemosorbent, Mogely Khubutiya, Boris Grafov, Mikhail M. Goldin, Alexei Davydov, Vladimir Kolesnikov, Mark Goldin

Faculty Publications and Presentations

The number of medical applications of electrochemistry has grown in recent years due to the increased applications of electrochemical concepts to various systems of the organism. This includes electrochemically controlled hemosorption detoxification, where the removal of toxicants is controlled by changing the potential of the hemosorbent. It is important to avoid Faradaic processes in the course of hemosorption, which can lead to the addition of electrochemically modified toxicants to blood. The probability of their occurrence should depend on the open-circuit potential of the activated carbon. In order to elucidate the identification of Faradaic reactions, a model system was investigated. The …

Supramolecular Organization Of Nanoparticles, Brenda M. Porta Linnell

Open Access Theses & Dissertations

The study of supramolecular structures with nano-architectures has become an active area of research in recent years. They have the potential to generate functional materials with applications in medicine and emerging technologies. In this dissertation, the supramolecular organization of gold nanoparticles (AuNP) and other nano-scale structures such as discrete styrene-based polymers was investigated. The synthesis and characterization of metal-mediated AuNPs systems using pendant ligands on the AuNP such as 11-diethylenetriamine-undecane-1-thiol, 11-Mercapto-undecanoic acid [2-(2-amino-ethylamino)-ethyl]-amide, Bis(11-oxo-nicotinic acid, undecine)disulfide, and 11-mercaptoundecanoic acid, and using Cu(II) to mediate the formation of supramolecular AuNP systems with sizes of 200 nm ¡V 3 fÃ?m, are …

Antioxidant Assay: The Dpph Method, Justin Rushing

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Effects On Ion Exchange By A Binary Liquid-Liquid Mixture Near The Critical Point, Jonathon Savoy

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Encapsulation And Release Of Small Molecules From Polymeric Micelles, Monica Boatwright

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Corahue Fluo-Chase Kit Revamped, David Jackson

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Water Quality Monitoring Of The Indiana Dunes National Lakeshore Great Marsh Complex, Evan Beyers, Jacob Yablonowski, Jonathan Schoer

Symposium on Research and Creative Expression (SORCE)

The Great Marsh complex of the Indiana Dunes National Lakeshore was drained extensively by humans, beginning in the late 1800’s to provide land for farming and residences. Since 1998, 500 acres of the Great Marsh complex have been undergoing restoration in an attempt to return them to their pre-developed conditions. To assess the success of the ongoing restoration on water quality, 15 different parameters used to assess water quality are being measured. Data collected from June 2007 through July 2011 indicates that the water quality is typical of that for a wetlands in this region, and that the Great Marsh …

Baseline Data Analysis Of The Throgren Basin Retrofit, Erin Argyilan, Jennifer Birchfield, Tom Goyne, Nicole Grabos, Caitlin Soley, Jennifer Wunsch

Symposium on Research and Creative Expression (SORCE)

The Thorgren Basin, located in Valparaiso, IN, was created as a component of the stormwater management system for the city. The basin’s primary function is to collect stormwater from two separate regions of the Salt Creek Watershed after large storm events, that is then discharged through a single outlet. In its current state the basin has limited infiltration capabilities due to a lack of vegetation and pervious surfaces. The Save the Dunes Conservation Fund, a local non-profit group, provided a cost share opportunity to naturalize Thorngren basin. The goal of the summer 2011 project was to create a monitoring strategy …