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2016

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Articles 156781 - 156810 of 159452

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Square Wave Voltammetric Determination Of Valproic Acid In Pharmaceutical Preparations, Ebru Türköz Acar, Ati̇ye Nur Onar Jan 2016

Square Wave Voltammetric Determination Of Valproic Acid In Pharmaceutical Preparations, Ebru Türköz Acar, Ati̇ye Nur Onar

Turkish Journal of Chemistry

The electrochemical behavior of valproic acid (VAL) was investigated using square wave voltammetry, cyclic voltammetry, and sampled direct current polarography and a new square wave voltammetric method was developed for determination of VAL in pharmaceutical preparations. VAL showed two reduction peaks at about --0.2 V and --0.8 V vs. Ag/AgCl 3 M KCl with a hanging mercury drop electrode in 0.05 M pH 3.3 Britton--Robinson (BR) buffer. These peaks were named peak I and peak II, respectively. The types of limiting current of both peaks were determined as diffusion controlled based on cyclic voltammetry studies. A linear calibration graph was …

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Durability Of Carbon/Conducting Polymer Composite Supported Pt Catalysts Prepared By Supercritical Carbon Dioxide Deposition, Gamze Bozkurt, Fulya Memi̇oğlu, Ayşe Bayrakçeken Yurtcan Jan 2016

Durability Of Carbon/Conducting Polymer Composite Supported Pt Catalysts Prepared By Supercritical Carbon Dioxide Deposition, Gamze Bozkurt, Fulya Memi̇oğlu, Ayşe Bayrakçeken Yurtcan

Turkish Journal of Chemistry

Polypyrrole (PPy)/carbon (C) composites were synthesized by oxidative chemical polymerization and used as support material for Pt nanoparticles. PPy/C supported Pt nanoparticles were prepared by using a promising catalyst preparation method, supercritical carbon dioxide (scCO$_{2})$ deposition. The prepared materials were characterized by using BET, TGA, XRD, and TEM techniques. Cyclic voltammetry was used in order to determine the electrocatalytic activity of the prepared catalyst for hydrogen oxidation and oxygen reduction reactions that occur in proton exchange membrane fuel cells (PEMFCs). The Pt loading obtained over the composite material was around 10{\%}. TEM results showed highly dispersed and small nanoparticles over …

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Sentiment Classification Using Negation As A Proxy For Negative Sentiment, Bruno Ohana, Brendan Tierney, Sarah Jane Delany Jan 2016

Sentiment Classification Using Negation As A Proxy For Negative Sentiment, Bruno Ohana, Brendan Tierney, Sarah Jane Delany

Conference papers

We explore the relationship between negated text and neg- ative sentiment in the task of sentiment classification. We propose a novel adjustment factor based on negation occur- rences as a proxy for negative sentiment that can be applied to lexicon-based classifiers equipped with a negation detec- tion pre-processing step. We performed an experiment on a multi-domain customer reviews dataset obtaining accuracy improvements over a baseline, and we further improved our results using out-of-domain data to calibrate the adjustment factor. We see future work possibilities in exploring nega- tion detection refinements, and expanding the experiment to a broader spectrum of opinionated …

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Voltammetric Determination Of Famotidine On A Disposable Pencil Graphite Electrode, Iulia Gabriela David, Dana Elena Popa, Andreea-Alexandra Calin, Mihaela Buleandra, Emilia-Elena Iorgulescu Jan 2016

Voltammetric Determination Of Famotidine On A Disposable Pencil Graphite Electrode, Iulia Gabriela David, Dana Elena Popa, Andreea-Alexandra Calin, Mihaela Buleandra, Emilia-Elena Iorgulescu

Turkish Journal of Chemistry

The present paper describes the use of a disposable pencil graphite electrode (PGE) for the voltammetric determination of famotidine. Cyclic voltammetric studies using different supporting electrolytes emphasized an irreversible oxidation of famotidine on the PGE. The electrode process is diffusion-controlled and pH-dependent. Differential pulse voltammetry (DPV) in phosphate buffer solution of pH 6.81 was employed for famotidine's quantitative determination. The anodic peak current of famotidine varies linearly with the analyte concentration in the range 4.72 $\times $ 10$^{-7}$--4.95 $\times $ 10$^{-4}$ M. Detection and quantification limits were 1.51 $\times $ 10$^{-7}$ M and 5.04 $\times $ 10$^{-7}$ M famotidine, respectively. …

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Adsorptive Features Of Polyacrylamide--Aluminosilicate Composites For Methylene Blue, Demet Baybaş, Ulvi̇ Ulusoy Jan 2016

Adsorptive Features Of Polyacrylamide--Aluminosilicate Composites For Methylene Blue, Demet Baybaş, Ulvi̇ Ulusoy

Turkish Journal of Chemistry

Polyacrylamide--montmorillonite (PAAm-Mt) and polyacrylamide--clinoptilolite (PAAm-Z) composites were prepared by cross-linked polymerization of acrylamide in dispersions of Mt and Z. The composites were characterized by FT-IR, SEM, XRD, CEC, and PZC analysis. The adsorptive features of PAAm-Mt and PAAm-Z for methylene blue (MB) were investigated by their relevance to initial dye concentration, temperature, contact time, PZC, and pH. The monolayer adsorption capacities were 0.14 and 0.08 mol kg$^{-1}$ for PAAm-Z and PAAm-Mt, respectively. The changes in pH of MB solution had an insignificant influence on their adsorption capacities. The values of enthalpy and entropy changes were positive ($\Delta $H$_{PAAm-Mt}$ = 7.6 …

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Liquid State $^{15}$N Nmr Studies Of $^{15}$N Isotope Labeled Phthalocyanines, Armağan Atsay, Ahmet Gül, Makbule Koçak Jan 2016

Liquid State $^{15}$N Nmr Studies Of $^{15}$N Isotope Labeled Phthalocyanines, Armağan Atsay, Ahmet Gül, Makbule Koçak

Turkish Journal of Chemistry

$^{15}$N labeled soluble metallo- and metal-free phthalocyanines are described for the first time. The complexes were synthesized starting from phthalic anhydride derivatives using 98{\%} $^{15}$N enriched urea. The effects of the substitution pattern, aggregation, and coordinated metal on $^{15}$N chemical shifts in liquid state NMR were studied.

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A Convenient Route For The Synthesis Of New Thiadiazoles, Abdelwahed Sayed, Yasser Zaki, Emad Aish Jan 2016

A Convenient Route For The Synthesis Of New Thiadiazoles, Abdelwahed Sayed, Yasser Zaki, Emad Aish

Turkish Journal of Chemistry

The present work describes the preparation of new thiadiazoles through a simple intramolecular reaction of mono- and bis-hydrazonoyl halides with methyl hydrogen phenyl carbonimidodithioate or methyl-2-arylidene hydrazinecarbodithioate. The synthetic method involves nucleophilic substitution followed by intramolecular cyclization reactions mediated by evolution of methanethiol. The structures of the title compounds were elucidated by elemental analyses, and FTIR, MS and NMR spectra.

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Wittig--Horner Reagents: Powerful Tools In The Synthesis Of 5-And 6-Heterocyclic Compounds; Shedding Light On Their Application In Pharmaceutical Chemistry, Rizk Elsayed Khidre, Wafaa Mahmoud Abdou Jan 2016

Wittig--Horner Reagents: Powerful Tools In The Synthesis Of 5-And 6-Heterocyclic Compounds; Shedding Light On Their Application In Pharmaceutical Chemistry, Rizk Elsayed Khidre, Wafaa Mahmoud Abdou

Turkish Journal of Chemistry

This paper reviews literature over 25 years' activity on phosphoryl carbanion reagents and shows that these compounds are powerful tools in organic chemistry. The main target of this review is to outline some of the reactive peculiarities that make this class of compounds powerful tools in the synthesis of 5- and 6-heterocyclic compounds and/or substituted heterocycle phosphor esters. The importance of these latter compounds in pharmacology is also discussed.

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Synthetic Approaches Towards The Synthesis Of Beta-Blockers (Betaxolol, Metoprolol, Sotalol, And Timolol), Furqan Ahmad Saddique, Ameer Fawad Zahoor, Muhammmad Yousaf, Muhammmad Irfan, Matloob Ahmad, Asim Mansha, Zulfiqar Ali Khan, Syed Ali Raza Naqvi Jan 2016

Synthetic Approaches Towards The Synthesis Of Beta-Blockers (Betaxolol, Metoprolol, Sotalol, And Timolol), Furqan Ahmad Saddique, Ameer Fawad Zahoor, Muhammmad Yousaf, Muhammmad Irfan, Matloob Ahmad, Asim Mansha, Zulfiqar Ali Khan, Syed Ali Raza Naqvi

Turkish Journal of Chemistry

Numerous efficient synthetic methodologies have been elaborated for the synthesis of $\beta $-blockers since the introduction of propranolol (a beta-blocker) in 1968. In this review, focus is placed on the more concise asymmetric and bioenzymatic synthetic approaches attempted towards the synthesis of beta-blockers (betaxolol, metoprolol, sotalol, and timolol).

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Immobilization Of Laccase Onto A Porous Nanocomposite: Application For Textile Dye Degradation, Sedef İlk, Deni̇z Demi̇rcan, Semran Sağlam, Necdet Sağlam, Zakir M. O. Rzayev Jan 2016

Immobilization Of Laccase Onto A Porous Nanocomposite: Application For Textile Dye Degradation, Sedef İlk, Deni̇z Demi̇rcan, Semran Sağlam, Necdet Sağlam, Zakir M. O. Rzayev

Turkish Journal of Chemistry

Poly(MA-\textit{alt}-MVE)-$g$-PLA/ODA-MMT nanocomposite was prepared by self-catalytic interlamellar graft copolymerization of L-lactic acid (LA) onto poly(maleic anhydride-\textit{alt}-methyl vinyl ether) copolymer in the presence of octadecyl amine-montmorillonite (ODA-MMT) organoclay. FTIR, $^{1}$H ($^{13}$C) NMR, XRD, and SEM-TEM were utilized for characterizing the resultant nanocomposite. Laccase from \textit{Trametes versicolor} was immobilized onto the prepared nanocomposite by adsorption or covalent coupling. Decolorization of Reactive Red 3 from aqueous solution by laccase immobilized on the nanocomposite was studied in different conditions (pH, temperature, dye concentration, and reaction time) to investigate the decolorization activity with repeated use and storage. The results indicated that more than 77{\%} of …

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The Role Of N-Heterocyclic Carbene Substituents On Ruthenium(Ii) Complexes In The Catalytic Transfer Hydrogenation Of Acetophenone, Muhammet Emi̇n Günay, Gülcan Gençay Çoğaşlioğlu Jan 2016

The Role Of N-Heterocyclic Carbene Substituents On Ruthenium(Ii) Complexes In The Catalytic Transfer Hydrogenation Of Acetophenone, Muhammet Emi̇n Günay, Gülcan Gençay Çoğaşlioğlu

Turkish Journal of Chemistry

The novel ruthenium(II) complexes [RuCl$_{2}$(NHC)($p$-cymene)], \textbf{3a}--\textbf{e}, containing 1-alkyl-3-benzylimidazol-2-ylidene ligands were prepared. All synthesized compounds were characterized by NMR spectroscopy and elemental analyses. Ru(II)-NHC complexes were tested as catalysts for the transfer hydrogenation of acetophenone, showing modest to high activity in this reaction. The results revealed that efficiencies depend on the substituents of the benzene ring of the benzyl on the N atom of the NHC ring.

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Enhanced Delivery Of Epirubicin By Polyoxometalate-Based Magnetic Nanocarriers: Controlled Drug Loading And Ph-Sensitive Drug Release, Ezzat Rafiee, Nasibeh Rahpeyma Jan 2016

Enhanced Delivery Of Epirubicin By Polyoxometalate-Based Magnetic Nanocarriers: Controlled Drug Loading And Ph-Sensitive Drug Release, Ezzat Rafiee, Nasibeh Rahpeyma

Turkish Journal of Chemistry

A series of polyoxometalate-based magnetic nanoparticles were developed as novel carriers for anticancer drugs. Characterization of the nanoparticles was done by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), wavelength dispersive X-ray (WDX), and laser particle size analyzer. Epirubicin (EPI) was selected as a model drug. EPI loading efficiency, EPI loading content, and EPI release profiles were studied. Drug loading was controlled using acid-base titration since H$^{+}$ was released during the loading process. Based on these investigations, an efficient EPI delivery system was introduced. It showed high EPI-loading capacity (35.2 wt.{\%}) and high EPI loading …

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Oxidative Dehydrogenation Of Propane Over V$_{2}$O$_{5}$ And K$_{2}$O-V$_{2}$O$_{5}$ Impregnated Mgal$_{2}$O$_{4}$Catalysts, Serkan Naci̇ Koç, Kübra Dayioğlu, Hasan Özdemi̇r Jan 2016

Oxidative Dehydrogenation Of Propane Over V$_{2}$O$_{5}$ And K$_{2}$O-V$_{2}$O$_{5}$ Impregnated Mgal$_{2}$O$_{4}$Catalysts, Serkan Naci̇ Koç, Kübra Dayioğlu, Hasan Özdemi̇r

Turkish Journal of Chemistry

V$_{2}$O$_{5}$ and K$_{2}$O-V$_{2}$O$_{5}$ impregnated MgAl$_{2}$O$_{4}$ catalysts were prepared and tested for the oxidative dehydrogenation of propane. The as-synthesized catalysts were characterized by using the XRD, BET, NH$_{3}$-TPD, TPR, and XPS methods. The catalytic tests were performed in a fixed bed tubular quartz reactor system between 450 and 550 $^{\circ}$C. It was observed that the conversion of propane increased but hydrocarbon selectivity decreased with increasing temperature over the V$_{2}$O$_{5}$/MgAl$_{2}$O$_{4}$ catalysts. The BET surface area values and surface acidities decreased upon potassium addition for the K-V$_{2}$O$_{5}$/MgAl$_{2}$O$_{4}$ catalysts, which resulted in a drastic drop in the conversion values obtained. The propylene and total …

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Investigation Of Long-Term Water Absorption Behavior Of Carbon Fabric Reinforced Epoxy Composites Containing Hydrophobic Nanosilica, Nurten Eki̇n, Mehmet Gali̇p İçduygu, Ahmet Gültek Jan 2016

Investigation Of Long-Term Water Absorption Behavior Of Carbon Fabric Reinforced Epoxy Composites Containing Hydrophobic Nanosilica, Nurten Eki̇n, Mehmet Gali̇p İçduygu, Ahmet Gültek

Turkish Journal of Chemistry

hydrophobic filler containing epoxy matrix composites was investigated by keeping them in distilled water for 9 months. Aerosil R812 (8 nm) and Aerosil R972 (12 nm) were utilized at 3{\%} and 5{\%} w/w filler to resin ratio and the resin/filler mixture was combined with 12-ply carbon fabric to get 15 $\times $ 15 cm samples. Samples were molded under a hot press and for each sample 50 test samples obtained by cutting them with a water jet. The obtained samples were characterized by TG, FTIR, and SEM. The effect of water absorption was evaluated by measuring percentage water absorption and …

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Polybrominated Methoxy- And Hydroxynaphthalenes, Kiymet Berki̇l Akar, Osman Çakmak, Tuncay Tunç Jan 2016

Polybrominated Methoxy- And Hydroxynaphthalenes, Kiymet Berki̇l Akar, Osman Çakmak, Tuncay Tunç

Turkish Journal of Chemistry

Regio- and stereoselective synthesis are described for convenient preparation of hydroxy- and methoxynaphthalenes starting from naphthalene (\textbf{1}). \textit{cis,cis,trans}-2,3,5,8-Tetrabromo-4-methoxy-1,2,3,4-tetrahydronaphthalen-1-ol (\textbf{6}), \textit{cis,cis,trans}-2,3,5,8-tetrabromo-1,4-dimethoxy-1,2,3,4-tetrahydronaphthalene (\textbf{7}), and \textit{cis,cis,cis}-2,3,5,8-tetrabromo-1,4-dimethoxy-1,2,3,4-tetrahydronaphthalene (\textbf{8}) were obtained with silver-induced substitution of \textit{trans,cis,trans}-1,2,3,4, 5,8-hexabromo-1,2,3,4-tetrahydronaphthalene (\textbf{3}). Base-promoted aromatization of dimethoxides \textbf{7} and \textbf{8} afforded 3,5,8-tribromo-1-methoxynaphthalene (\textbf{9}) and 2,5,8-tribromo-1-methoxynaphthalene (\textbf{10}). The reaction of \textbf{6 }with sodium methoxide formed compounds \textbf{10 }and 3,5,8-tribromonaphthalen-1-ol (\textbf{16}). Bromination of \textbf{9} and\textbf{ 16} with Br$_{2}$ in dichloromethane at room temperature produced 2,3,5,8-tetrabromo-1-methoxynaphthalene (\textbf{14}) and 2,3,4,5,8-pentabromonaphthalen-1-ol (\textbf{18}), respectively, while compound \textbf{10} did not react in the same conditions. Pyridine-induced elimination of hexabromide \textbf{3} afforded 1,4,6\textbf{-}tribromnaphthalene (\textbf{21}) in 99{\%} yield and …

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Heterogeneous Fenton-Like Degradation Of Acid Red 17 Using Fe-Impregnated Nanoporous Clinoptilolite: Artificial Neural Network Modeling And Phytotoxicological Studies, Alireza Khataee, Mehrangiz Fathinia, Soghra Bozorg Jan 2016

Heterogeneous Fenton-Like Degradation Of Acid Red 17 Using Fe-Impregnated Nanoporous Clinoptilolite: Artificial Neural Network Modeling And Phytotoxicological Studies, Alireza Khataee, Mehrangiz Fathinia, Soghra Bozorg

Turkish Journal of Chemistry

Heterogeneous Fenton-like removal of Acid Red 17 (AR17) from aqueous solution was investigated. Fe-impregnated nanoporous clinoptilolite (Fe-NP-Clin) was prepared by an impregnation method and used as a catalyst. A complete characterization including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), inductively coupled plasma (ICP), and Brunauer--Emmett--Teller (BET) analyses was done to describe the physical and chemical properties of NP-Clin and Fe-NP-Clin samples. The effects of five operational parameters, i.e. solution pH, H$_{2}$O$_{2}$ dosage, catalyst loading, AR17 concentration, and reaction time, on the removal efficiency of AR17 were studied. For the first time, an artificial neural network …

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Impregnation Of Different Ionic Liquids Onto Cationic Starch And Their Comparison In The Extraction Of Th(Iv), Eli̇f Ant Bursali, Serap Seyhan Bozkurt, Mürüvvet Yurdakoç Jan 2016

Impregnation Of Different Ionic Liquids Onto Cationic Starch And Their Comparison In The Extraction Of Th(Iv), Eli̇f Ant Bursali, Serap Seyhan Bozkurt, Mürüvvet Yurdakoç

Turkish Journal of Chemistry

Cationic starch (CS) was prepared by using epichlorohydrin (EPI) and 3-chloro-2-hydroxypropyltrimethy- lammonium chloride (CHPTMA) and ionic liquids (ILs) having different anionic groups [1-butyl-3-methyl imidazolium tetrafluoroborate (BMI$^{+}$BF$_{4}^{-})$, 1-butyl-3-methyl imidazolium bromide (BMI$^{+}$Br$^{-})$, 1-butyl-3-methyl imidazolium hexafluorophosphate (BMI$^{+}$PF$_{6}^{-})$, and 1-butyl-3-methyl imidazolium bis-[(trifluoromethyl)sulfonyl]imide (BMI$^{+}$ [(TF)$_{2}$N]$^{-})$] were impregnated onto CS. Thorium(IV) ions were preconcentrated by using IL impregnated CS. The effects of ILs were investigated for extraction of Th(IV) by CS and the results were compared. Th(IV) was preconcentrated with approximately 73{\%} sorption capacity by CS and increased up to 98{\%}--100{\%} for IL impregnated sorbents at pH 7.0. The sorption capacities of Th(IV) were 0.453 mmol …

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Suppression Of Interfering Ions By Using Ionic Liquid And Micelle Moieties In Spectrofluorimetric Analysis Of Manganese, Özlem Öter, Müge Aydin, Kadri̇ye Erteki̇n Jan 2016

Suppression Of Interfering Ions By Using Ionic Liquid And Micelle Moieties In Spectrofluorimetric Analysis Of Manganese, Özlem Öter, Müge Aydin, Kadri̇ye Erteki̇n

Turkish Journal of Chemistry

Eosin-Y exhibits high affinity and emission based spectral response to most of the major ions in water samples. In the present study we performed selective spectrofluorimetric analysis of manganese with eosin-Y in the presence of potential interferents. We employed green chemistry reagents, ionic liquids (ILs) and two different micelles, to suppress the effect of conventional cations and anions on the response of eosin-Y. The experimental data revealed that different test moieties caused enhanced analytical response to Mn$^{2+}$. The highest analytical signal of eosin-Y was obtained in the presence of Triton X-100 at a concentration of 2.0 $\times $ 10$^{-3}$ mol …

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New Antimicrobial Biscembrane Hydrocarbon And Cembranoid Diterpenes From The Soft Coral Sarcophyton Trocheliophorum, Muhammad Zubair, Walied Alarif, Khalid Al-Footy, Mohamed Ph, Magda Ali, Salim Basaif, Sultan Al-Lihaibi, Seif-Eldin Ayyad Jan 2016

New Antimicrobial Biscembrane Hydrocarbon And Cembranoid Diterpenes From The Soft Coral Sarcophyton Trocheliophorum, Muhammad Zubair, Walied Alarif, Khalid Al-Footy, Mohamed Ph, Magda Ali, Salim Basaif, Sultan Al-Lihaibi, Seif-Eldin Ayyad

Turkish Journal of Chemistry

A new tetracyclic biscembrane hydrocarbon, trocheliane (1), along with two new cembranoid diterpenes, sarcotrocheldiol A (2) and B (3), and the known diterpene cembrene-C (4), were isolated from the Red Sea soft coral Sarcophyton trocheliophorum. The structures and relative stereochemistry of the compounds were elucidated by interpretation of MS, 1 D NMR, and 2 D NMR experiments. The sensitivity of some pathogenic bacteria used as test organisms to the new compounds 1-3 was determined. 1 showed appreciable antimicrobial activity with the diameter of inhibition zones ranging from 11 to 18 mm. 1 was active against the two multidrug resistant bacteria …

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Synthesis And Evaluation Of Novel $N,N'$-Disubstituted Benzimidazolium Bromides Salts As Antitumor Agents, Hasan Küçükbay, Akin Mumcu, Suat Teki̇n, Süleyman Sandal Jan 2016

Synthesis And Evaluation Of Novel $N,N'$-Disubstituted Benzimidazolium Bromides Salts As Antitumor Agents, Hasan Küçükbay, Akin Mumcu, Suat Teki̇n, Süleyman Sandal

Turkish Journal of Chemistry

Novel benzimidazolium bromides salts having (4-methoxyphenyl)ethyl, (phthalimide-2-yl)methyl, 4-nitro- benzyl, 2-phenylethyl, penthyl, or allyl groups were synthesized and their characterizations were conducted by $^{1}$H and $^{13}$C NMR and IR spectroscopic methods, and microanalysis. In vitro antitumor activities of the novel benzimidazole compounds (1-7) were determined by using ovarian (A2780) and prostate (PC-3) cancer cell lines. Antitumor properties of all compounds were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. A time-dependent cell viability assay for the tested benzimidazole compounds was performed and the IC$_{50}$ values of the compounds were calculated after treatment for 24 and 48 h. Our results indicate that the tested …

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Photocatalysis Of Formaldehyde In The Aqueous Phase Over Zno/Diatomite Nanocomposite, Reza Darvishi Cheshmeh Soltani, Alireza Khataee, Masumeh Mashayekhi, Mahdi Safari Jan 2016

Photocatalysis Of Formaldehyde In The Aqueous Phase Over Zno/Diatomite Nanocomposite, Reza Darvishi Cheshmeh Soltani, Alireza Khataee, Masumeh Mashayekhi, Mahdi Safari

Turkish Journal of Chemistry

In the present study, ZnO nanostructures were synthesized and immobilized on the surface of diatomite via a simple sonochemical method for the photocatalytic degradation of formaldehyde in the aqueous phase. The characterization of as-prepared ZnO/diatomite nanocomposite was carried out by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The photocatalysis of formaldehyde was favored at neutral pH. At a ZnO to diatomite ratio of 0.3, increasing the photocatalyst dosage from 0.2 to 1.5 g/L resulted in increasing the photocatalytic removal of formaldehyde from 37.51% to 88.05%. At a formaldehyde concentration of 100 mg/L, …

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Synthesis And Application Of Polyvinylimidazole-Based Bronsted Acidic Ionic Liquid Grafted Silica As An Efficient Heterogeneous Catalyst In The Preparation Of Quinoxaline Derivatives, Bahman Tamami, Alireza Sardarian, Elaheh Ataollahi Jan 2016

Synthesis And Application Of Polyvinylimidazole-Based Bronsted Acidic Ionic Liquid Grafted Silica As An Efficient Heterogeneous Catalyst In The Preparation Of Quinoxaline Derivatives, Bahman Tamami, Alireza Sardarian, Elaheh Ataollahi

Turkish Journal of Chemistry

Two types of polymer-grafted silica based on polyvinylimidazole Bronsted acidic ionic liquids were prepared and used as new heterogeneous catalysts for the preparation of pharmaceutically important quinoxaline derivatives. These catalysts were characterized by thermogravimetric analysis, FT-IR spectroscopy, and titration. They could be recycled without considerable loss in their catalytic activity. High efficiency of the catalysts along with short reaction times, high yields, easy purification, recyclability, and simple procedure are among the advantages of these catalytic systems.

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Visible Light Photocatalysis Of A Textile Dye Over Zno Nanostructures Covered On Natural Diatomite, Reza Darvishi Cheshmeh Soltani, Zohreh Haghighat Jan 2016

Visible Light Photocatalysis Of A Textile Dye Over Zno Nanostructures Covered On Natural Diatomite, Reza Darvishi Cheshmeh Soltani, Zohreh Haghighat

Turkish Journal of Chemistry

In the present study, ZnO nanostructures were ultrasonically synthesized and immobilized on the surface of diatomite and used for visible light photocatalysis of Acid Red 88 (AR88) in the aqueous phase. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were employed for characterization of the samples. The process was optimized via response surface methodology (RSM) on the basis of central composite design (CCD). Based on numerical optimization, for the maximized color removal of 96% the initial dye concentration, the catalyst dosage, the reaction time, and the initial pH were 13 mg/L, 1.5 g/L, 85 min, and 4, respectively. The …

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Ecofriendly One-Pot Synthesis And Antiviral Evaluation Of Novel Pyrazolyl Pyrazolines Of Medicinal Interest, Sobhi Gomha, Magda Abdalla, Mohamad Abd El-Aziz, Nany Serag Jan 2016

Ecofriendly One-Pot Synthesis And Antiviral Evaluation Of Novel Pyrazolyl Pyrazolines Of Medicinal Interest, Sobhi Gomha, Magda Abdalla, Mohamad Abd El-Aziz, Nany Serag

Turkish Journal of Chemistry

Ethyl 3-acetyl-1,5-diphenyl-1$H$-pyrazole-4-carboxylate reacts with a variety of arylaldehydes by grinding method in the presence of a catalytic amount of sodium hydroxide at ambient temperature to give the respective chalcones. The latter compounds react also by grinding method with nitrogen nucleophiles such as hydrazine hydrate, phenylhydrazine, and thiosemicarbazide to afford the corresponding pyrazol-3-yl pyrazolines. A series of 6-pyrazolylpyrimidine-2-thione derivatives were prepared by reaction of the above chalcones with thiourea by grinding method in the presence of a catalytic amount of sodium hydroxide at room temperature. In addition, 7-pyrazolylpyridopyrimidine-3-thione was prepared by reaction of chalcone with 6-aminothiouracil. All the newly synthesized compounds …

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Comparative Density Functional Study Of Antioxidative Activity Of The Hydroxybenzoic Acids And Their Anions, Zoran Markovic, Jelena Djorovic, Jasmina M. Dimitric Markovic, Radomir Biocanin, Dragan Amic Jan 2016

Comparative Density Functional Study Of Antioxidative Activity Of The Hydroxybenzoic Acids And Their Anions, Zoran Markovic, Jelena Djorovic, Jasmina M. Dimitric Markovic, Radomir Biocanin, Dragan Amic

Turkish Journal of Chemistry

Hydroxybenzoic acids (HBAs) and their anions play an important role in the food and pharmaceutical industries because of their antioxidant activity. In this study, we examined the mechanisms of the free radical scavenging action of HBAs and their anions using density functional theory (DFT) methods. Reaction enthalpies related to the mechanisms of free radical scavenging by the investigated species were calculated by DFT methods in water, DMSO, pentylethanoate, and benzene. Hydrogen atom transfer (HAT) is a preferred reaction pathway in benzene, while sequential proton loss electron transfer (SPLET) is a predominant reaction pathway in polar solvents, water, and DMSO for …

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Prostereoisomerism And Biological Activity: Possible Implications For Drug Design, Sosale Chandrasekhar Jan 2016

Prostereoisomerism And Biological Activity: Possible Implications For Drug Design, Sosale Chandrasekhar

Turkish Journal of Chemistry

Prostereoisomerism (PIM), representing a subgroup within the achiral class of molecules, is manifested in a chiral environment. Although this is regardless of the orientation of the prostereoisomeric (PIC) molecule, PIM is manifested most emphatically in relation to a chiral surface (`two-dimensional chirality'). Then PIM is tantamount to `de facto chirality' as attachment of the PIC molecule to the surface leads to diastereomeric possibilities (cf. Ogston's hypothesis). Furthermore, the formation of host--guest complexes requires a steric complementarity between the component molecules. The fact that the weak dispersive forces involved therein require an optimum distance implies a `snugness of fit' criterion. This …

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The Mediatory Activity Of Meso-Tetraphenylporphyrin Iron(Iii) Complex Immobilized In Nafion Film On A Pt Electrode In The Oxidation Of 1,2- And 1,4-Hydroquinones, Slawomir Domagala, Slawomira Skrzypek, Michal Cichomski, Andrzej Leniart Jan 2016

The Mediatory Activity Of Meso-Tetraphenylporphyrin Iron(Iii) Complex Immobilized In Nafion Film On A Pt Electrode In The Oxidation Of 1,2- And 1,4-Hydroquinones, Slawomir Domagala, Slawomira Skrzypek, Michal Cichomski, Andrzej Leniart

Turkish Journal of Chemistry

This paper presents the results of an investigation of the properties of a modified platinum electrode with meso-tetraphenylporphyrin iron(III) complex immobilized in Nafion film and its catalytic activity in the electrochemical oxidation of selected hydroquinone and catechol derivatives. The redox activity of iron complexes of porphyrins was characterized in aqueous solutions of perchloric acid by means of cyclic voltammetry and differential pulse voltammetry. Both the increase in the anodic peak currents of the investigated compounds during oxidation on the platinum electrode modified with meso-tetraphenylporphyrin iron(III) complex immobilized in Nafion film (FeTPhP/Nafion/Pt) and the considerable decrease in the cathodic peak currents …

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Understanding The Everyday Designer In Organisations, Ciaran O'Leary, Fredrick Mtenzi, Claire Mcavinia Jan 2016

Understanding The Everyday Designer In Organisations, Ciaran O'Leary, Fredrick Mtenzi, Claire Mcavinia

Conference papers

This paper builds upon the existing concept of an everyday designer as a non-expert designer who carries out design activities using available resources in a given environment. It does so by examining the design activities undertaken by non-expert, informal, designers in organisations who make use of the formal and informal technology already in use in organisations while designing to direct, influence, change or transform the practices of people in the organisation. These people represent a cohort of designers who are given little attention in the literature on information systems, despite their central role in the formation of practice and enactment …

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Characterization Of An Al$^{3+}$-Selective Fluorescent Probe Based On A Benzoyl Hydrazine Derivative And Its Application In Cell Imaging, Yuxiang Ji, Chunwei Yu, Shaobai Wen, Jun Zhang Jan 2016

Characterization Of An Al$^{3+}$-Selective Fluorescent Probe Based On A Benzoyl Hydrazine Derivative And Its Application In Cell Imaging, Yuxiang Ji, Chunwei Yu, Shaobai Wen, Jun Zhang

Turkish Journal of Chemistry

A fluorescent probe based on benzoyl hydrazine was synthesized and characterized as an Al$^{3+}$-selective fluorescent probe. This probe showed good selectivity towards Al$^{3+\, }$compared to other common ions. Under optimized experimental conditions, the probe exhibited a linear dynamic response for Al$^{3+}$ from 5.0 $\times $ 10$^{-7}$ to 4.5 $\times $ 10$^{-6}$ M with a detection limit of 1.3 $\times $ 10$^{-7}$ M in ethanol-water solution (9:1, v:v, pH 6.8, 20 mM HEPES). Furthermore, it was used for imaging of Al$^{3+}$ in living cells with satisfying results.

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Synthesis Of Novel Thiazolylpyrazoline Derivatives And Evaluation Of Their Antimicrobial Activities And Cytotoxicities, Aouatef Tabbi, Zafer Asim Kaplancikli, Dahmane Tebbani, Leyla Yurttaş, Zerri̇n Cantürk, Özlem Atli, Merve Baysal, Gülhan Turan Zitouni Jan 2016

Synthesis Of Novel Thiazolylpyrazoline Derivatives And Evaluation Of Their Antimicrobial Activities And Cytotoxicities, Aouatef Tabbi, Zafer Asim Kaplancikli, Dahmane Tebbani, Leyla Yurttaş, Zerri̇n Cantürk, Özlem Atli, Merve Baysal, Gülhan Turan Zitouni

Turkish Journal of Chemistry

Several novel thiazolylpyrazoline derivatives were synthesized by reacting substituted 3,5-diaryl-1-thiocarba\-moyl-2-pyrazolines with phenacylbromides. The structures of the synthesized compounds were confirmed by IR, $^{1}$H NMR, $^{13}$C NMR, and MS spectral data. Their antimicrobial activities against Staphylococcus aureus(ATCC-25923), Enterococcus faecalis} (ATCC-29212), Enterococcus faecalis (ATCC-51922), Listeria monocytogenes (ATCC-1911), Klebsiella pneumoniae (ATCC-700603), Pseudomonas aeruginosa (ATCC-27853), Escherichia coli (ATCC-35218), Escherichia coli (ATCC-25922), Candida albicans (ATCC-90028), Candida glabrata (ATCC-90030), Candida krusei (ATCC-6258), and Candida parapsilosis (ATCC-22019) were investigated. The compounds were also studied for their cytotoxic effects using a MTT assay. Compound 7c showed the highest antimicrobial activity, possessing the same potential as chloramphenicol against K. …

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