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Articles 11281 - 11310 of 33250

Full-Text Articles in Chemistry

Synthesis And Bioactivity Of Sulfide Derivatives Containing 1,3,4-Oxadiazole And Pyridine, Gang Yu, Shunhong Chen, Feng He, Dexia Luo, Yu Zhang, Jian Wu Jan 2019

Synthesis And Bioactivity Of Sulfide Derivatives Containing 1,3,4-Oxadiazole And Pyridine, Gang Yu, Shunhong Chen, Feng He, Dexia Luo, Yu Zhang, Jian Wu

Turkish Journal of Chemistry

A series of novel sulfide derivatives containing 1,3,4-oxadiazole and pyridine were synthesized, characterized, and tested for their antibacterial activity against tobacco bacterial wilt and rice bacterial blight and for insecticidal activity toward diamondback moth. The results showed that some compounds had good insecticidal and bactericidal activity, e.g., the activities of compounds 6e and 6g-6j toward tobacco bacterial wilt were much better than those of commercial thiodiazole-copper, and some of the synthesized compounds possessed good insecticidal activity against Plutella xylostella. Compounds 6d, 6h, 6j, 6l, 6p, 6r, and 6p displayed over 93% activity at 500 mg L$^{-1}$.

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Targeting Human Telomeric Dna With Azacyanines, Ayça Küçükakdağ Doğu, Özgül Persi̇l Çeti̇nkol Jan 2019

Targeting Human Telomeric Dna With Azacyanines, Ayça Küçükakdağ Doğu, Özgül Persi̇l Çeti̇nkol

Turkish Journal of Chemistry

Small molecules targeting telomeric DNA or its interactions with telomerase have been an active area of cancer research. In the present study, we investigated the interactions of six benzimidazole compounds, called azacyanines, differing from each other in alkyl chain length and branching in the benzimidazole ring (azamethyl, azaethyl, azapropyl, azaisopropyl, azabutyl, and azaisobutyl) with human telomeric DNA (tel24) in 1:1 and 1:6 ratio (tel24:azacyanine) using UV-Vis, circular dichroism (CD), and fluorescence spectroscopy. All the compounds were binding to tel24 as indicated by the formation of the weak induced CD band between 320 nm and 360 nm. A substantial red shift …

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Optical Characterization Of Salt-Induced Swelling Behavior Of Poly($N$-Isopropylacrylamide) Terpolymer Hydrogel Layers, İlke Anaç, Anil Bozdoğan Jan 2019

Optical Characterization Of Salt-Induced Swelling Behavior Of Poly($N$-Isopropylacrylamide) Terpolymer Hydrogel Layers, İlke Anaç, Anil Bozdoğan

Turkish Journal of Chemistry

This study reports for the first time the effect of different sodium halide salts (NaClO$_{4}$, NaI, and Na$_{2}$CO$_{3})$ in the low concentration range (in the range of 10$^{-7}$-1 M) on the swelling behavior of photo-crosslinked, surface-immobilized poly($N$-isopropyl acrylamide) (PNIPAAm) terpolymer layers. PNIPAAm terpolymer (consisting of $N$-isopropylacrylamide, methacrylic acid, and 4-methacryloxybenzophenone) was synthesized via free radical polymerization. The PNIPAAm terpolymer layers were prepared on gold substrates via spin coating and crosslinked and surface attached via UV radiation. The swelling behavior of the layers in monovalent (NaClO$_{4}$ and NaI) and divalent (Na$_{2}$CO$_{3})$ solutions was monitored by surface plasmon/optical waveguide spectroscopy. The terpolymer …

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Molecular Dynamics Simulations Of Adsorption Of Long Pyrene-Peg Chains On A Thin Carbon Nanotube, Peli̇n Deni̇z Akkuş, Ayşe Özge Kürkçüoğlu Levi̇tas Jan 2019

Molecular Dynamics Simulations Of Adsorption Of Long Pyrene-Peg Chains On A Thin Carbon Nanotube, Peli̇n Deni̇z Akkuş, Ayşe Özge Kürkçüoğlu Levi̇tas

Turkish Journal of Chemistry

Carbon nanotubes have emerged as highly promising theranostic agents due to their unique structural/physical features, high surface area, and high drug-loading capacity. The high cytotoxicity of carbon nanotubes can be eliminated by noncovalent coating using hydrophilic polymers. We investigated the adsorption of long pyrene functionalized polyethylene glycol (PEG) chains, PEG$_{2000}$ and PEG$_{5000}$, on a single-walled carbon nanotube (SWNT) from a crowded solution. Full-atom molecular dynamics simulations in explicit water were used to mimic the experimental conditions of noncovalent PEGylation with a stoichiometry of one SWNT to ten pyrene-PEG. Although the diffusional behavior of the pyrene molecules still attached to the …

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Acetyl- And Butyrylcholinesterase Inhibitory Activity Of Selected Photochemically Synthesized Polycycles, Ivana Sagud, Irena Skoric, Dragana Vuk, Ana Ratkovic, Franko Burcul Jan 2019

Acetyl- And Butyrylcholinesterase Inhibitory Activity Of Selected Photochemically Synthesized Polycycles, Ivana Sagud, Irena Skoric, Dragana Vuk, Ana Ratkovic, Franko Burcul

Turkish Journal of Chemistry

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the main cause of dementia in the elderly population. Since the treatment of AD has been associated with the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), their inhibitors remain the main focus of AD investigations. In this study we evaluated cholinesterase inhibitory activity of 14 bicyclo[3.2.1]octene/octadiene derivatives and naturally occurring sesquiterpene alcohol cedrol. These 14 compounds have been efficiently and ecologically prepared by a photochemical approach in batch photochemical reactors. Various compounds with the bicyclo[3.2.1]octene skeleton have already been successfully evaluated for treatment of central nervous system disorders and AD. Among …

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Reduced Graphene Oxide Supported Tin Oxide-Boron Oxide Flexible Paper Anodes For Li-Ion Batteries, Hi̇lal Köse, Şeyma Dombaycioğlu, Hatem Akbulut, Ali̇ Osman Aydin Jan 2019

Reduced Graphene Oxide Supported Tin Oxide-Boron Oxide Flexible Paper Anodes For Li-Ion Batteries, Hi̇lal Köse, Şeyma Dombaycioğlu, Hatem Akbulut, Ali̇ Osman Aydin

Turkish Journal of Chemistry

Freestanding tin oxide-boron oxide/reduced graphene oxide (SnO$_{2}$-B$_{2}$O$_{3}$/rGO) nanocomposite anode was produced for Li-ion cells. This binder-free flexible paper anode structure was fabricated by combining SnO$_{2}$-B$_{2}$O$_{3}$ composite and graphene oxide which were synthesized through the sol-gel method and Hummers' method, respectively. Field emission gun scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectrometer, Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction were utilized to characterize anode materials. The Williamson-Hall (W-H) analysis was applied using XRD data to determine crystal size and strain of the lattice. Electrochemical tests, cyclic voltammetry, and electrochemical impedance spectroscopy measurements were performed to determine …

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Anticancer And Antiangiogenesis Activities Of Novel Synthesized 2-Substituted Benzimidazoles Molecules, Adem Güner, Eli̇fsu Polatli, Tamer Akkan, Hakan Bektaş, Canan Albay Jan 2019

Anticancer And Antiangiogenesis Activities Of Novel Synthesized 2-Substituted Benzimidazoles Molecules, Adem Güner, Eli̇fsu Polatli, Tamer Akkan, Hakan Bektaş, Canan Albay

Turkish Journal of Chemistry

In this study, novel 2-substituted benzimidazoles molecules having triazole, thiadiazole, and oxadiazole rings were synthesized and were evaluated by anticancer, antioxidant/oxidant status, genotoxicity, and antiangiogenesis assays. Anticancer activity of the compounds was determined by MTT (0.5, 5, and 50 $\mu $g/mL) and lactate dehydrogenase (LDH) release assays against human prostate and breast cancer cells. Oxidative status of cells was elicited by total oxidative stress and total antioxidant capacity methods. Chick chorioallantoic membrane assay was used to evaluate the antiangiogenic activity. Genotoxicity was evaluated by the sister chromatid exchange (SCE) and micronucleus (MN) tests in lymphocyte cultured human blood. Our results …

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Ionic Liquid-Based Graphene Oxide-Coated Fiber For Headspace-Solid Phase Microextraction Of Polycyclic Aromatic Hydrocarbons In Water Samples, Peli̇n Erdem, Paniz Tashakkori, Melek Merdi̇van, Serap Seyhan Bozkurt Jan 2019

Ionic Liquid-Based Graphene Oxide-Coated Fiber For Headspace-Solid Phase Microextraction Of Polycyclic Aromatic Hydrocarbons In Water Samples, Peli̇n Erdem, Paniz Tashakkori, Melek Merdi̇van, Serap Seyhan Bozkurt

Turkish Journal of Chemistry

Ionic liquid (IL) containing amino and vinyl terminated imidazolium cation and bis[(trifluoromethyl)sulfonyl] imide anion-functionalized graphene oxide (GO) coating material was prepared and coated on a stainless steel wire by a sol-gel technique for headspace-solid phase microextraction (HS-SPME). Its extraction performance was checked by HS-SPME of polycyclic aromatic hydrocarbons (PAHs) coupled to gas chromatography with mass spectrometry (GC-MS). The extraction capability of the IL-functionalized GO-coated fiber was comparable with that of the commercial fibers of polydimethylsiloxane (PDMS) and polydimethylsiloxane/carboxen/divinylbenzene (PDMS/CAR/DVB). Under the optimized conditions, such as extraction temperature, extraction time, and salting-out, the proposed HS-SPME-GC-MS method presented a wide working range …

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Glucose Oxidase Immobilized Biofuel Cell Flow Channel Geometry Analysis By Cfd Simulations, Sali̇h Obut, Tahsi̇n Bahar Jan 2019

Glucose Oxidase Immobilized Biofuel Cell Flow Channel Geometry Analysis By Cfd Simulations, Sali̇h Obut, Tahsi̇n Bahar

Turkish Journal of Chemistry

Glucose oxidase was covalently immobilized to a porous electrode, which was developed by using ferrocene functionalized polyethyleneimine, multiwall carbon nanotubes, and carbon cloth for biofuel cell applications in our recent studies. The kinetics parameters (i.e. k$_{M}$, V$_{max})$ and other parameters required for the modeling study were determined experimentally. Fuel cell flow channel geometry was analyzed by a computational fluid dynamics modeling approach. Substrate flow rate and mass transfer for each proposed channel type were considered in the simulations. The results showed that serpentine type flow channels are advantageous over pin type or parallel flow channels to acquire sufficient performance from …

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Synthesis And Characterization Of Novel Mussel-Inspired Benzoxazines By Thiol-Benzoxazine Chemistry, Mustafa Arslan Jan 2019

Synthesis And Characterization Of Novel Mussel-Inspired Benzoxazines By Thiol-Benzoxazine Chemistry, Mustafa Arslan

Turkish Journal of Chemistry

A catechol-based benzoxazine copolymer is reported via a new approach using an oxazine-thiol reaction. The main chain benzoxazine precursor was obtained via the classic benzoxazine synthesis methodology using the raw chemicals catechol, formaldehyde, and 4,7,10-trioxa-1,13-tridecanediamine. The countercomponent was synthesized from poly(ethylene glycol) methyl ether via the Fischer esterification reaction. The obtained reactive catechol-based benzoxazine was then reacted in mild conditions with polymeric thiol precursor to obtain a copolymer structure. The precursors and the resulting structure were characterized by thermal and spectral analyses using DSC, TGA, FT-IR,$^{\, 1}$H NMR, and GPC. Film formation was also demonstrated with unreacted oxazine ring units …

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Stability Improvement By Crosslinking Of Previously Immobilized Glucose Oxidase On Carbon Nanotube-Based Bioanode, Tahsi̇n Bahar Jan 2019

Stability Improvement By Crosslinking Of Previously Immobilized Glucose Oxidase On Carbon Nanotube-Based Bioanode, Tahsi̇n Bahar

Turkish Journal of Chemistry

Bioanode stability with glucose oxidase was enhanced significantly by covalent crosslinking without substantial enzymatic activity and affinity loss. Initially, glucose oxidase was immobilized by aldehyde groups on the electrode that was developed using ferrocenecarboxaldehyde, polyethyleneimine, multiwall carbon nanotubes, and carbon cloth for biofuel cell applications. The glucose oxidase half-life was extended by more than 4 times, from 27.2 to 124.7 h, after the electrode was crosslinked. Enzymatic kinetic parameters were determined for the crosslinked enzyme and they were compared to the noncrosslinked immobilized enzyme parameters on the electrode. The apparent substrate affinity of the crosslinked enzyme electrode was decreased (i.e. …

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Synthesis Of N-Heterocyclic Molecules And Their Applicability Towards Ion Sensing: Polymeric Chemosensors, Aikohi M. Ugboya Jan 2019

Synthesis Of N-Heterocyclic Molecules And Their Applicability Towards Ion Sensing: Polymeric Chemosensors, Aikohi M. Ugboya

College of Graduate Studies: Theses & Dissertations

Critical to biological and environmental processes are anions because often times their relative concentration in our body can be an indicator of one’s well-being. Therefore, highly sensitive and cost-efficient methods for ions recognition is necessary for human health. In recent times, polymeric chemosensors have become a vital tool for sensing ions because of its higher sensitivity and good mechanical properties compared to their monomeric counterparts. These sensors are designed to produce a measurable response in the presence of a targeted ion such as an electrochemical or optical signal. The unique structure and the photophysical properties of the 1,2,3-triazole core coupled …

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Hydrogen Storage In Formic Acid As A Renewable Energy Source Using Heterogeneous Catalysis, Obaid Aldosari Jan 2019

Hydrogen Storage In Formic Acid As A Renewable Energy Source Using Heterogeneous Catalysis, Obaid Aldosari

Turkish Journal of Chemistry

One of the most vital chemicals, which is not only found naturally but can also be synthesized in the laboratory, is formic acid (FA). FA is a key byproduct of several second-generation biorefinery processes as well, and it is used in several pharmaceutical and industrial applications. Recently, another significant use of FA that is taking the lead is as a form of fuel. This could either involve reformation, as a possible form of chemical hydrogen storage, or be done without reformation in the form of FA fuel cells, in particular because FA fuel cells are much more effective than other …

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Amperometric Urea Biosensor Based On Immobilized Urease On Polypyrrole And Macroporous Polypyrrole Modified Pt Electrode, Maliheh Hosseinian, Ghasem Najafpour, Ahmad Rahimpour Jan 2019

Amperometric Urea Biosensor Based On Immobilized Urease On Polypyrrole And Macroporous Polypyrrole Modified Pt Electrode, Maliheh Hosseinian, Ghasem Najafpour, Ahmad Rahimpour

Turkish Journal of Chemistry

Biosensing of urea by a biosensor as a direct detection method at ambient temperature and pressure instead of chromatography leads to a significant reduction in processing costs. Amperometric biosensors based on urease immobilization on macroporous polypyrrole (MPPy) and pyrrole on the surface of a Pt electrode were developed. Applying cyclic voltammetry (CV), we demonstrated the synthesis of MPPy using monodispersed polystyrene spheres (460 nm) as a template. CV and chronoamperometric studies were conducted to evaluate the electrochemical current of the modified electrodes. For the electrode with polypyrrole (PPy), the biosensor response was linear in the range of 1.67--8.32 mM (R$^{2}$ …

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Antioxidant Properties Of Water-Soluble Phthalocyanines Containing Quinoline 5-Sulfonic Acid Groups, Armağan Günsel, Esma Hande Alici, Ahmet Turgut Bi̇lgi̇çli̇, Gülnur Arabaci, Meryem Ni̇lüfer Yaraşir Jan 2019

Antioxidant Properties Of Water-Soluble Phthalocyanines Containing Quinoline 5-Sulfonic Acid Groups, Armağan Günsel, Esma Hande Alici, Ahmet Turgut Bi̇lgi̇çli̇, Gülnur Arabaci, Meryem Ni̇lüfer Yaraşir

Turkish Journal of Chemistry

In the present study, the antioxidant properties of peripherally and nonperipherally water-soluble tetra (quinoline 5-sulfonic acid) substituted metal-free (1,2), Zn(II) (3, 4), Co(II) (5, 6), and Mn(III)Cl (7, 8) phthalocyanine (Pc) derivatives were reported. In order to determine the antioxidant properties of the Pc compounds, three different commonly known antioxidant methods were used: DPPH ($\alpha $,$\alpha $-diphenyl-$\beta $-picrylhydrazyl) radical scavenging, ferrous ion chelating, and reducing power assays. Compound \textbf{6} showed the best DPPH activity among the other tested compounds except for the standards. The ferrous ion chelating IC$_{50\, }$value of compound 7 was nearly as good as that of the …

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Detection Of Lard Contamination In Five Different Edible Oils By Ft-Ir Spectroscopy Using A Partial Least Squares Calibration Model, Fazeelah Munir, Syed Ghulam Musharraf, Syed Tufail Hussain Sherazi, Muhammad Imran Malik, Muhmmad Iqbal Bhanger Jan 2019

Detection Of Lard Contamination In Five Different Edible Oils By Ft-Ir Spectroscopy Using A Partial Least Squares Calibration Model, Fazeelah Munir, Syed Ghulam Musharraf, Syed Tufail Hussain Sherazi, Muhammad Imran Malik, Muhmmad Iqbal Bhanger

Turkish Journal of Chemistry

Lard is defined as animal fat acquired from the adipose tissue of pigs and is not permitted for human consumption or external use by certain religions such as Islam and Judaism. Due to its low-cost availability for commercial use, it is often mixed with other vegetable oils mistakenly or deliberately and causes loss of consumer trust; hence, its detection in food products is essential. Consumers tend to know the authenticity of commercially available edible oils. However, edible oils are subjected to adulteration risks with lard, which breaches consumer rights. In the present study, we designed a transmission Fourier transform infrared …

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Synthesis Of Smz Derivatives And Investigation Of Effects On Germination, Root, And Plant Growth Of \Textit{Arabidopsis Thaliana} L., Tuğba Güngör, Ferah Cömert Önder, Fati̇h Sezer, Aslihan Özbi̇len, Kemal Meli̇h Taşkin, Mehmet Ay Jan 2019

Synthesis Of Smz Derivatives And Investigation Of Effects On Germination, Root, And Plant Growth Of \Textit{Arabidopsis Thaliana} L., Tuğba Güngör, Ferah Cömert Önder, Fati̇h Sezer, Aslihan Özbi̇len, Kemal Meli̇h Taşkin, Mehmet Ay

Turkish Journal of Chemistry

A series of sulfonamide derivatives were synthesized by reactions with various functional groups containing benzenesulfonyl chlorides and aniline derivatives under different substitution reaction conditions. The structures of SMZ derivatives were confirmed with melting point, FT-IR, $^{1}$H NMR, $^{13}$C NMR, and LC-MS/MS techniques. In order to investigate the cytotoxic effects of these derivatives, we used a model plant species. The synthesized compounds (S1-S5) and sulfamethazine (SMZ) as a positive control were applied to Arabidopsis thaliana seeds. Our results indicated that S3 and S4 induced shorter roots and lower wet weight in plants. Plants treated with S2 and S5 showed no growth …

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Novel Voltammetric Investigation Of Dipyridamole At A Disposable Pencil Graphite Electrode, Iulia Gabriela David, Lorelei Iordache, Dana Elena Popa, Mihaela Buleandra, Victor David, Emilia-Elena Iorgulescu Jan 2019

Novel Voltammetric Investigation Of Dipyridamole At A Disposable Pencil Graphite Electrode, Iulia Gabriela David, Lorelei Iordache, Dana Elena Popa, Mihaela Buleandra, Victor David, Emilia-Elena Iorgulescu

Turkish Journal of Chemistry

The present paper describes the voltammetric analysis of dipyridamole (DIP) at a cheap, disposable pencil graphite electrode (PGE). The working conditions were optimized with regard to the electrode material and the supporting electrolyte. Cyclic voltammetric investigations emphasized that DIP is irreversibly oxidized at the PGE. The electrode process is pH-dependent and controlled by both diffusion and adsorption. For DIP quantitative determination a differential pulse voltammetric (DPV) method in phosphate buffer solution pH 7.00 was developed. DIP's oxidation peak current varied linearly with the analyte concentration, presenting two linear ranges, namely 5.00 $\times $ 10$^{-7}$-2.50 $\times $ 10$^{-5}$ M and 2.50 …

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$N$-Acylazole Mediated Stereoselective And Regioselective Synthesis Of $N$-Substituted Azole Acrylonitriles, Osman Aydin, Şule Kökten, Hakan Ünver, İlhami̇ Çeli̇k Jan 2019

$N$-Acylazole Mediated Stereoselective And Regioselective Synthesis Of $N$-Substituted Azole Acrylonitriles, Osman Aydin, Şule Kökten, Hakan Ünver, İlhami̇ Çeli̇k

Turkish Journal of Chemistry

Regio- and stereoselective synthesis of $N$-substituted azole acrylonitriles has been achieved smoothly in $N,N$-dimethylformamide (DMF) in the presence of potassium carbonate (K$_{2}$CO$_{3})$ as a base catalyst. $N$-Substituted azole acrylonitriles were obtained in moderate to good yields (39%-87%) with a one-pot reaction between readily available $N$-acetylazoles and Baylis-Hillman nitriles. The structural determinations were accomplished by NOESY $^{1}$H NMR and X-ray crystallography.

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On The Azo Dyes Derived From Benzoic And Cinnamic Acids Used As Photosensitizers In Dye-Sensitized Solar Cells, Luka Matovic, Nikola Tasic, Nemanja Trisovic, Jelena Ladarevic, Vesna Vitnik, Zeljko Vitnik, Branimir Grgur, Dusan Mijin Jan 2019

On The Azo Dyes Derived From Benzoic And Cinnamic Acids Used As Photosensitizers In Dye-Sensitized Solar Cells, Luka Matovic, Nikola Tasic, Nemanja Trisovic, Jelena Ladarevic, Vesna Vitnik, Zeljko Vitnik, Branimir Grgur, Dusan Mijin

Turkish Journal of Chemistry

In order to get a better insight into the relationship between molecular structure and photovoltaic performance, six monoazo dye molecules containing benzoic and cinnamic acid moieties were synthesized and their photovoltaic properties were studied. Three of them have not been previously used in solar cells. Spectroscopic measurements of the investigated compounds coupled with theoretical calculations were performed. Short-circuit current density, open-circuit voltage, and fill-factor were determined. It was found that a larger amount of short-circuit current density will be generated if the HOMO--LUMO energy gap is lower, determined by the stability of the molecule and the electronic effect of the …

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Amino-Functionalized Mesostructured Cellular Foam Silica: A Highly Efficient And Recyclable Catalyst In The Knoevenagel Condensation Reaction, Dong Hao, Hongyuan Yang, Tengfei Zhang, Qing Liu Jan 2019

Amino-Functionalized Mesostructured Cellular Foam Silica: A Highly Efficient And Recyclable Catalyst In The Knoevenagel Condensation Reaction, Dong Hao, Hongyuan Yang, Tengfei Zhang, Qing Liu

Turkish Journal of Chemistry

Mesostructured cellular foam silica was functionalized by an amino group (MCF-NH$_{2})$ using the postsynthesis grafting method and utilized as a recyclable catalyst for the Knoevenagel reaction to afford $\alpha $, $\beta $-unsaturated compounds. The catalyst was systematically characterized by various analyses such as nitrogen adsorption, X-ray diffraction, Fourier transform infrared spectrophotometry, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and Hammett indicator method. The results showed that MCF-NH$_{2}$ catalyst was successfully prepared with a high surface area of 215 m$^{2}$ g$^{-1}$ and a large pore volume of 1.37 cm$^{3}$ g$^{-1}$. Compared with the nonfunctionalized MCF sample, the window and cell …

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A Novel Silver(I)-Selective Pvc Membrane Sensor And Its Potentiometric Applications, Ömer Işildak, Ni̇hal Deli̇gönül, Oğuz Özbek Jan 2019

A Novel Silver(I)-Selective Pvc Membrane Sensor And Its Potentiometric Applications, Ömer Işildak, Ni̇hal Deli̇gönül, Oğuz Özbek

Turkish Journal of Chemistry

Silver(I)-selective sensors were prepared from a solid-state contact polyvinyl chloride (PVC) membrane. ($Z)$-2-(2-((3-(2-hydroxyphenyl)-5-(p-tolyl)-1$H$-pyrrol-2-yl)imino)-5-(p-tolyl)-2$H$-pyrrol-3-yl)phenol was synthesized as an ionophore molecule and embedded in the silver(I)-selective PVC membrane composition. The optimum membrane composition was determined as 2.5% ionophore, 61.7% bis-(2-ethylhexyl)sebacate, 1.0% potassium tetrakis (p-chlorophenyl) borate, and 34.8% PVC. The developed sensor exhibited a linear potential change $E$ = 67.42 (-log [Ag$^{+}$]) $+$ 1152.9 and $R^{2}$ = 0.9960) in the varying concentration range of 1.0 $\times $ 10$^{-1}$ to 1.0 $\times $ 10$^{-5}$ mol L$^{-1}$ silver ions. This sensor shows a detection limit of 7.3 $\times $ 10$^{-7}$ mol L$^{-1}$. The proposed sensor …

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Determination Of N-Acetylcysteine In The Presence Of Ciprofloxacin Or Levofloxacin In Microparticulate Dry Powder Inhalers, Yağmur Akdağ Çayli, Selma Şahi̇n, Emi̇rhan Nemutlu, Levent Öner Jan 2019

Determination Of N-Acetylcysteine In The Presence Of Ciprofloxacin Or Levofloxacin In Microparticulate Dry Powder Inhalers, Yağmur Akdağ Çayli, Selma Şahi̇n, Emi̇rhan Nemutlu, Levent Öner

Turkish Journal of Chemistry

A fast and easy method was validated for simultaneous determination of ciprofloxacin hydrochloride monohydrate (CP), levofloxacin hemihydrate (LV), and N-acetylcysteine (NAC) in samples. The analysis was performed on a C$_{18}$ column (250 x 4.6 mm, 5 μm) (Inertsil ODS-3V) using an isocratic elution method with a mobile phase composed of 25 mM KH$_{2}$PO$_{4}$ (pH 3.0) and methanol (72:28, v/v) at a flow rate of 1 mL/min. UV detection was performed at 214 nm for NAC and 293 nm for CP and LV. The method was validated for linearity, accuracy, precision (repeatability and reproducibility), specificity, sensitivity, and stability. The calibration study …

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Qualitative And Quantitative Determination Of The Effective Components Of The Plants In Different Herbal Slimming Products In Turkey By Hplc, Benan Dursunoğlu, Hafi̇ze Yuca, Sefa Gözcü, Bi̇lal Yilmaz, Zühal Güvenalp Jan 2019

Qualitative And Quantitative Determination Of The Effective Components Of The Plants In Different Herbal Slimming Products In Turkey By Hplc, Benan Dursunoğlu, Hafi̇ze Yuca, Sefa Gözcü, Bi̇lal Yilmaz, Zühal Güvenalp

Turkish Journal of Chemistry

Obesity is a serious disease that can be due to genetic and environmental reasons and is defined by the World Health Organization as abnormal or excessive fat accumulation that may impair health. There is an increasing trend towards herbal slimming products in obesity treatment. The quality control analysis of these products is important for public health. In this study, new, simple, and sensitive high performance liquid chromatography methods were developed for qualitative and quantitative determination of arbutin, hydroquinone, ursolic acid, chlorogenic acid, epigallocatechin gallate, epigallocatechin, epicatechin gallate, and catechin in eleven herbal slimming products in Turkey containing Camellia sinensis, Ilex …

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Enhanced Uptake Capacities And Isosteric Heats Of Co$_{2}$ And Ch$_{4}$ Adsorption On Spent Coffee Ground Activated Carbons Loaded With Metal Ions, Çi̇sem Kirbiyik, Burak Zafer Büyükbekar, Mahmut Kuş, Mustafa Ersöz Jan 2019

Enhanced Uptake Capacities And Isosteric Heats Of Co$_{2}$ And Ch$_{4}$ Adsorption On Spent Coffee Ground Activated Carbons Loaded With Metal Ions, Çi̇sem Kirbiyik, Burak Zafer Büyükbekar, Mahmut Kuş, Mustafa Ersöz

Turkish Journal of Chemistry

Low-cost activated carbon (AC) samples obtained from waste coffee grounds were used for CO$_{2}$ and CH$_{4}$ adsorption. ACs were prepared by chemical activation and carbonized at three different temperatures. AC carbonized at 800 $^{\circ}$C showed a relatively high surface area (582.92 m$^{2}$ g$^{-1})$ and high adsorption capacities of 2.6 mmol g$^{-1}$ and 1.1 mmol g$^{-1}$ at 25 $^{\circ}$C for CO$_{2}$ and CH$_{4}$, respectively. Adsorbent samples were prepared by loading of Fe$^{3+}$ metal ions onto ACs and their adsorption capacities were compared with those of nonloaded ACs. As expected, the loading of Fe$^{3+}$ metal ions increased the adsorption capacities at all …

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Alpha-Pyrone Glycosides From Scutellaria Salviifolia Benth, Zeynep Doğan, Kan'ichiro Ishiuchi, Toshiaki Makino, İclal Saraçoğlu Jan 2019

Alpha-Pyrone Glycosides From Scutellaria Salviifolia Benth, Zeynep Doğan, Kan'ichiro Ishiuchi, Toshiaki Makino, İclal Saraçoğlu

Turkish Journal of Chemistry

Scutellaria salviifolia Benth. is an endemic species growing in Turkey that belongs to the family Lamiaceae. As a result of a phytochemical study on the aerial parts of S. salviifolia Benth., two new and 10 known compounds were isolated from the aqueous fraction of methanolic extract. The new compounds are methyl-$\alpha $-pyrone glucosides, 3,4-dihydroxy-6-methylpyran-2-one 3-$O$-$\beta $-glucopyranoside (=scusalvioside A, 1), and 3,4-dihydroxy-6-methylpyran-2-one 3-$O$-$\beta $-(6$'$-$O$-$E$-caffeoyl) glucopyranoside (=scusalvioside B, 2) with new skeletal structures. Along with them, 3 phloroglucinol glucosides [phlorin (3), tadehaginoside (4), and 6$^{\prime \prime} $-$O$-$Z$-$p$-coumaroyl phloroglucinol-1-$O$-$\beta $-glucopyranoside (5)], 6 flavonoids [apigenin (6), apigenin 5-$O$-$\beta $-glucopyranoside (7), isoschaftoside (8), luteolin 7-$O$-$\beta …

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Synthesis, Characterization, And Nonlinear Optical Properties Of Some New Series Of S-(5-Aryl-1,3,4-Oxadiazol-2-Yl) 2-Chloroethanethioate Derivatives, Zahra Dono Ghezelbash, Hamideh Motiei, Miri Mahmoody, Karim Akbari Delmaghani Jan 2019

Synthesis, Characterization, And Nonlinear Optical Properties Of Some New Series Of S-(5-Aryl-1,3,4-Oxadiazol-2-Yl) 2-Chloroethanethioate Derivatives, Zahra Dono Ghezelbash, Hamideh Motiei, Miri Mahmoody, Karim Akbari Delmaghani

Turkish Journal of Chemistry

In the present investigation, some novel S-(5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate (3a-3e) derivatives were synthesized and their impact on optical properties was studied. They have also been characterized by elemental analysis and various spectroscopic methods including FTIR, $^{1}$H NMR, $^{13}$C NMR, and UV-Vis techniques. The nonlinear refractive indexes of 3a-3e were also measured in dichloromethane via Z-scan method using a continuous wave diode-pumped laser at 532 nm wavelength. The nonlinear refractive coefficient of compounds was obtained from ${10}^{11}\, \, {m}^{{2}}{/W}$ order. Regarding the appropriate nonlinearity of these compounds, they could be considered good candidates for biooptical and photonic applications. All the synthesized compounds (3a-3e) …

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Bisbenzoxazole Derivatives Had An Antiinflammatory Effect On In Vitro Stimulated Macrophages, Furkan Ayaz, Rusmeenee Kheeree, Qadar Ahmed Isse, Ronak Haj Ersan, Özteki̇n Algül Jan 2019

Bisbenzoxazole Derivatives Had An Antiinflammatory Effect On In Vitro Stimulated Macrophages, Furkan Ayaz, Rusmeenee Kheeree, Qadar Ahmed Isse, Ronak Haj Ersan, Özteki̇n Algül

Turkish Journal of Chemistry

Benzoxazoles are DNA base bioisosteres and studies suggest that their derivatives have antiproliferative activities. Based on their antiproliferative activities they have been mostly studied as new generation anticancer drugs. In our study we exploited their antiproliferative effect, aiming to delineate bisbenzoxazole derivatives' (RHE 231 and RHE 238) potential antiinflammatory effect on mouse macrophages that are activated in vitro through danger signal LPS stimulation. RAW 267.4 mammalian macrophages were activated in the presence of our derivatives with or without danger mimic E. coli derived LPS. We present data that support the strong antiinflammatory activity of the bisbenzoxazole derivatives RHE 231 and …

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A Theoretical Investigation On The Activation Of Small Molecules By A Disilenide: A Dft Prediction, Cem Burak Yildiz, Akin Azi̇zoğlu Jan 2019

A Theoretical Investigation On The Activation Of Small Molecules By A Disilenide: A Dft Prediction, Cem Burak Yildiz, Akin Azi̇zoğlu

Turkish Journal of Chemistry

Herein, we proposed several mechanistic scenarios for activation of small molecules (NH$_{3}$, CO$_{2}$, CS$_{2}$, H$_{2}$, CH$_{4}$, N$_{2}$, and N$_{2}$O) by a disilicon analogue of a vinyl anion (1H) using density functional theory (DFT) calculations. The DFT results established that all the possible reactions to yield a variety of potential products have an exergonic nature except for the activation of N$_{2}$ with the obtained overall energy of $\Delta $G = 33.6 kcal mol$^{-1}$. Moreover, the highest exergonic character was $\Delta $G = $-$95.8 kcal mol$^{-1}$ for N$_{2}$O. Therefore, the findings reveal that 1H can be considered a suitable candidate for activation …

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Synthesis And Spectroscopic Characterization Of New Phthalocyanine Derivatives: Application As Photocatalysts For The Degradation Of Orange G, Yusuf Yilmaz, Kayode Sanusi Jan 2019

Synthesis And Spectroscopic Characterization Of New Phthalocyanine Derivatives: Application As Photocatalysts For The Degradation Of Orange G, Yusuf Yilmaz, Kayode Sanusi

Turkish Journal of Chemistry

New derivatives of 2(3),9(10),16(17),23(24)-tetrakis-(6-methylpyridin-2-yloxy)phthalocyanine (Pc) (2b, 2c, and 2d) were synthesized and their structures were characterized by elemental analysis, IR, $^{1}$H NMR, and high-resolution mass spectrometry. The spectral results were in line with the proposed structures. The photodegradation of Orange G (OG) dye in DMSO by the Pc derivatives was investigated. The compounds showed relatively high photodegradation rates that increased with increasing size of the central atoms. The Pc photodegradation rates showed fair correlation with the singlet oxygen generation efficiencies (${\Phi }_{{\Delta }})$. The observed rate constants were higher than the values already reported for other Pcs in the literature …

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