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Articles 1261 - 1290 of 1559
Full-Text Articles in Chemistry
Extraction Of Heavy Metal Complexes From A Biofilm Colony For Biomonitoring The Pollution, Sedat Sürdem, Haci Mehmet Doğan
Extraction Of Heavy Metal Complexes From A Biofilm Colony For Biomonitoring The Pollution, Sedat Sürdem, Haci Mehmet Doğan
Turkish Journal of Chemistry
An extraction method was tested for biomonitoring the biofilm samples containing heavy metals. The fractionation of metal complexes was performed via C-18-HPLC-ICP-MS and MALDI-MS, respectively. The extraction power of some reagents was determined for the heavy metal extraction from biofilm samples collected in Erdemli coast in the Mediterranean Sea. The ammonium acetate solution giving the highest extraction results was found as a suitable extraction reagent. The concentration and pH of the ammonium acetate solution were optimized and found as 1 M and 5, respectively. The chromatograms of metal complexes with the C-18-HPLC-ICP-MS system were taken to determine the effect of …
Synthesis And Liquid Crystalline Properties Of New Triazine-Based $\Pi $-Conjugated Macromolecules With Chiral Side Groups, Ni̇hat Akkurt, Mohammed Hadi Ali Al-Jumaili, Hale Ocak, Fati̇h Çakar, Lokman Torun
Synthesis And Liquid Crystalline Properties Of New Triazine-Based $\Pi $-Conjugated Macromolecules With Chiral Side Groups, Ni̇hat Akkurt, Mohammed Hadi Ali Al-Jumaili, Hale Ocak, Fati̇h Çakar, Lokman Torun
Turkish Journal of Chemistry
In this study, we reported the synthesis of a new tribranched macromolecule liquid crystal with triazine in the centre. The central triazine core is bonded via sequences of Sonigashira coupling to 3 triazine unites through acetylenic bridges. The triazines at the periphery are substituted with 2 chiral citronellyloxy side groups. The salt of the resulting star-shaped macromolecule, which was oily at room temperature, with 4-dodecyloxybenzoic acid at 1:1 ratio exhibited a Smectic C (SmC) mesophase. The liquid crystalline properties of organic salt were investigated using DSC (differential scanning calorimetry) and POM (polarizing optical microscopy).
Synthesis, Characterization And Crystal Structures Of Platinum(Ii) Saccharinate Complexes With 1,5-Cyclooctadiene, Ceyda İçsel
Synthesis, Characterization And Crystal Structures Of Platinum(Ii) Saccharinate Complexes With 1,5-Cyclooctadiene, Ceyda İçsel
Turkish Journal of Chemistry
Two new platinum(II) complexes, namely [PtCl(sac)(COD)] (1) and [Pt(sac)$_{2}$(COD)] (2) (sac $=$ saccharinate and COD $=$ 1,5-cyclooctadiene), were synthesized and characterized by elemental analysis, IR, NMR, ESI-MS spectroscopic and thermal analysis (TG/DTA) methods. The platinum(II) complexes were prepared from the reaction of [PtCl$_{2}$(COD)] with Na(sac) • 2H$_{2}$O. The addition of the sac ligand resulted in the replacement of 1 and 2 chlorido ligands in [PtCl$_{2}$(COD)] to yield 1 and 2, respectively. The structures of the complexes were determined by single crystal X-ray diffraction and showed a distorted square planar coordination geometry around platinum(II). COD acted as a $\pi $-donor ligand, …
Preparation Of Rapid (Chain-Stopped) Alkyds By Incorporation Of Gum Rosin And Investigation Of Coating Properties, Cemi̇l Dizman, Eli̇f Ozman
Preparation Of Rapid (Chain-Stopped) Alkyds By Incorporation Of Gum Rosin And Investigation Of Coating Properties, Cemi̇l Dizman, Eli̇f Ozman
Turkish Journal of Chemistry
In this study, the synthesis, characterization, and properties of a short oil length chain--stopped(rapid) alkyd resin is investigated. Gum rosin modified alkyd resin (RA-GR) was prepared using soybean oil, phthalic anhydride, glycerin and gum rosin acid. An alkyd modified with benzoic acid (RA-BA) was also prepared for comparison. FTIR analyses and GPC measurements of the alkyds were used for characterization. Other properties such as the viscosity, acid value, and solid content of the final resins were determined. Separately, the synthesized resins were used in paint formulations without any changes in other parameters such as filler, airdrying agents, solvents, etc. Paints …
Characterization, Mechanical, And Antibacterial Properties Of Nanofibers Derived From Olive Leaf, Fumitory, And Terebinth Extracts, Ni̇lşen Sünter Eroğlu, Suat Canoğlu, Meti̇n Yüksek
Characterization, Mechanical, And Antibacterial Properties Of Nanofibers Derived From Olive Leaf, Fumitory, And Terebinth Extracts, Ni̇lşen Sünter Eroğlu, Suat Canoğlu, Meti̇n Yüksek
Turkish Journal of Chemistry
In this study, nanofiber structures were obtained with convenient polymers (PVA [polyvinyl alcohol] and PCL [poly º-caprolactone]) derived from the herbal extracts of olive leaves, fumitory, and terebinth plants. Optimum nanofiber structures were identified by measuring viscosity and conductivity values and performing morphological analysis, characterization, and mechanical tests of the prepared solutions. The potential use for wound healing at the most efficient level was determined as a result of antibacterial analysis of the structures obtained. APT (PVA/terebinth) and BFO (PCL/fumitory) nanofibers had the thinnest diameter range and the highest strength values. In terms of the determination of antibacterial effects, nanofiber …
Fluorescent Sensing Platform For Low-Cost Detection Of Cu$^{\Mathbf{2+}}$ By Coumarin Derivative: Dft Calculation And Practical Application In Herbal And Black Tea Samples, Tahi̇r Savran, Abdurrahman Karagöz, Şükri̇ye Ni̇han Karuk Elmas, Duygu Aydin, Furkan Özen, Kenan Koran, Fatma Nur Arslan, Ahmet Orhan Görgülü, İbrahi̇m Yilmaz
Fluorescent Sensing Platform For Low-Cost Detection Of Cu$^{\Mathbf{2+}}$ By Coumarin Derivative: Dft Calculation And Practical Application In Herbal And Black Tea Samples, Tahi̇r Savran, Abdurrahman Karagöz, Şükri̇ye Ni̇han Karuk Elmas, Duygu Aydin, Furkan Özen, Kenan Koran, Fatma Nur Arslan, Ahmet Orhan Görgülü, İbrahi̇m Yilmaz
Turkish Journal of Chemistry
A fluorogenic probe based on a coumarin-derivative for Cu$^{2+}$ sensing in CH$_{3}$CN/H$_{2}$O media (v/v, 95/5, 5.0 \textmu M) was developed and applied in real samples. 3-(4-chlorophenyl)-6,7-dihydroxy-coumarin (MCPC) probe was obtained by synthetic methodologies and identified by spectral techniques. The probe MCPC showed remarkable changes with a ``turn-off'' fluorogenic sensing approach for the monitoring of Cu$^{2+}$ at 456 nm under an excitation wavelength of 366 nm. The response time of the probe MCPC was founded as only 1 min. The detection limit of the probe MCPC was recorded to be 1.47 nM. The binding constant and possible stoichiometric ratio (1:1) values …
Effect Of Mg Doping On Morphology, Photocatalytic Activity And Related Biological Properties Of Zn$_{\Mathbf{1-X}}$ Mg$_{X}$ O Nanoparticles, Bestenur Yalçin, Doğan Akcan, İbrahi̇m Ertuğrul Yalçin, Mehmet Can Alphan, Kenan Şentürk, İbrahi̇m İlker Özyi̇ği̇t, Lütfi̇ Arda
Effect Of Mg Doping On Morphology, Photocatalytic Activity And Related Biological Properties Of Zn$_{\Mathbf{1-X}}$ Mg$_{X}$ O Nanoparticles, Bestenur Yalçin, Doğan Akcan, İbrahi̇m Ertuğrul Yalçin, Mehmet Can Alphan, Kenan Şentürk, İbrahi̇m İlker Özyi̇ği̇t, Lütfi̇ Arda
Turkish Journal of Chemistry
The objective of this study is to synthesize ZnO and Mg doped ZnO (Zn$_{1-x}$Mg$_{x}$O) nanoparticles via the sol-gel method, and characterize their structures and to investigate their biological properties such as antibacterial activity and hemolytic potential.Nanoparticles (NPs) were synthesized by the sol-gel method using zinc acetate dihydrate (Zn(CH$_{3}$COO)$_{2}$.2H$_{2}$O) and magnesium acetate tetrahydrate (Mg(CH$_{3}$COO)$_{2}$.4H$_{2}$O) as precursors. Methanol and monoethanolamine were used as solvent and sol stabilizer, respectively. Structural and morphological characterizations of Zn$_{1-x}$Mg$_{x}$O nanoparticles were studied by using XRD and SEM-EDX, respectively. Photocatalytic activities of ZnO and selected Mg-doped ZnO (Zn$_{1-x}$Mg$_{x}$O) nanoparticles were investigated by degradation of methylene blue (MeB). Results …
A Road Map To Assess Critical Materials Content In Boron Industrial Wastes Usingsustainable Micro-X-Ray Fluorescence And Total Reflection X-Ray Fluorescenceinstrumentation, İbrahi̇m Kula, Christian Gutsche, Yunus Erdoğan, Andreas Fittschen, Ursula Elisabeth Adriane Fittschen
A Road Map To Assess Critical Materials Content In Boron Industrial Wastes Usingsustainable Micro-X-Ray Fluorescence And Total Reflection X-Ray Fluorescenceinstrumentation, İbrahi̇m Kula, Christian Gutsche, Yunus Erdoğan, Andreas Fittschen, Ursula Elisabeth Adriane Fittschen
Turkish Journal of Chemistry
Turkey is the leading country in the world in terms of boron production and sale. Increasing boron production goes along with an increasing generation of boron wastes. The pollution of the soil and the air around the waste piles, as well as the occupation of several square kilometers of ground, are major environmental problems. It is, therefore, very important to make use of the wastes to both protect the environment and create revenue. This work presenteda road map for fast screening of boron waste for critical elements followed by determination of the elements using small footprint low power instrumentation. The …
A Novel Molecular Imprinting Polymer For The Selective Adsorptionof D-Arabinitol From Spiked Urine, Yuni Retnaningtyas, Ganden Supriyanto, Ni Nyoman Tri Puspaningsih, Roedi Irawan, Siswandono Siswodihardjo
A Novel Molecular Imprinting Polymer For The Selective Adsorptionof D-Arabinitol From Spiked Urine, Yuni Retnaningtyas, Ganden Supriyanto, Ni Nyoman Tri Puspaningsih, Roedi Irawan, Siswandono Siswodihardjo
Turkish Journal of Chemistry
In this research, molecular imprinting polymers (MIPs) for D-arabinitol were synthesized using a bulk polymerization method through a noncovalent approach. The MIPs were prepared by using D-arabinitol as a template, acrylamide as a functional monomer, ethylene glycol dimethacrylateas cross-linker, benzoyl peroxide as an initiator and dimethyl sulfoxideas a porogen. MIPS was synthesized in several formulas with a different molar ratio of template to functional monomers and cross-linker. Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) were used to characterize the MIPs produced. A batch rebinding assay was used to test the binding efficiency of each formula. Batch rebinding test …
Design, Synthesis, And Spasmolytic Activity Of Thiophene-Based Derivatives Via Suzukicross-Coupling Reaction Of 5-Bromothiophene-2-Carboxylic Acid: Their Structural Andcomputational Studies, Nasir Rasool, Hafiz Mansoor Ikram, Ammara Rashid, Nazia Afzal, Muhammad Ali Hashmi, Muhammad Naeem Khan, Ayesha Khan, Imran Imran, Hafiz Muhammad Abdur Rahman, Syed Adnan Ali Shah
Design, Synthesis, And Spasmolytic Activity Of Thiophene-Based Derivatives Via Suzukicross-Coupling Reaction Of 5-Bromothiophene-2-Carboxylic Acid: Their Structural Andcomputational Studies, Nasir Rasool, Hafiz Mansoor Ikram, Ammara Rashid, Nazia Afzal, Muhammad Ali Hashmi, Muhammad Naeem Khan, Ayesha Khan, Imran Imran, Hafiz Muhammad Abdur Rahman, Syed Adnan Ali Shah
Turkish Journal of Chemistry
In the current research work, a facile synthesis of a series of novel thiophene-based derivatives of 5-bromothiophene-2- carboxylic acid (1) have been synthesized. All analogs (5a-5e, 10a-10f) were obtained from the coupling reaction of 5-bromothiophene- 2-carboxylic acid (1) and different arylboronic acids with moderate-to-good yields under controlled and optimal conditions. The structures of the newly synthesized compounds were characterized through spectral analysis and their spasmolytic activity, and most of the compounds exhibited potentially good spasmolytic effect. Among the synthesized analogs, compound phenethyl 5-(3,4-dichlorophenyl)thiophene-2-carboxylate (10d) particular showed an excellent spasmolytic effect with an EC$_{50}$ value of 1.26. All of the compounds …
Characterization And Kinetics Analysis Of The Thermal Decomposition Of The Humic Substance From Hazelnut Husk, Fatma Kara, Duygu Adigüzel, Ufuk Atmaca, Murat Çeli̇k, Jale Nakti̇yok
Characterization And Kinetics Analysis Of The Thermal Decomposition Of The Humic Substance From Hazelnut Husk, Fatma Kara, Duygu Adigüzel, Ufuk Atmaca, Murat Çeli̇k, Jale Nakti̇yok
Turkish Journal of Chemistry
A humic substance was obtained from hazelnut husk using an alkali extraction. The chemical and morphological structure of the humic matter was characterized via elemental analysis, Fourier transform infrared spectrometry (FTIR), nuclear magnetic resonance, Brunauer-Emmet-Teller (BET) analysis, scanning electron microscopy (SEM), and thermogravimetric-FTIR (TG-FTIR). In addition, thermal analysis measurements TG analysis-differential thermogravimetry/differential scanning calorimetry (TGA-DTG/ DSC) were performed under dynamic air conditions to better determine the origin, physical and chemical structure, and decomposition process of the humic matter. The Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods were used to calculate the kinetic parameters of the high-temperature decomposition process. It was observed …
Newly Synthesized Peripherally Octa-Substituted Zinc Phthalocyanines Carrying Halogenterminated Phenoxy-Phenoxy Moiety: Comparative Photochemical And Photophysicalfeatures, Erkan Kirbaç, Ali̇ Erdoğmuş
Newly Synthesized Peripherally Octa-Substituted Zinc Phthalocyanines Carrying Halogenterminated Phenoxy-Phenoxy Moiety: Comparative Photochemical And Photophysicalfeatures, Erkan Kirbaç, Ali̇ Erdoğmuş
Turkish Journal of Chemistry
This study reports the 3 new phthalonitrile derivatives, namely 4, 5 Bis-[4-(4-bromophenoxy) phenoxy] phthalonitrile (1), 4,5 Bis-[4-(4-chlorophenoxy) phenoxy]phthalonitrile (2), and 4, 5 Bis[4-(4-fluorophenoxy) phenoxy] phthalonitrile (3). Their octasubstituted zinc phthalocyanines (4, 5, 6) are reported for the first time in this study. The resulting compounds were characterized by utilizing some spectroscopic methods, such as UV-Vis, 1HNMR, FT-IR spectroscopy, as well as mass spectraand elemental analysis. To show photosynthesizer's potential, emission (FF), singlet oxygen (1O2), and photodegradation quantum yields (ΦΔ, Φd) of octaperipherally phthalocyanines (Pcs) were performed in the solutions, such as biocompatible solvent DMSO (dimethyl sulfoxide) as well as DMF …
N‑Linked Glycosylation Prevents Deamidation Of Glycopeptide And Glycoprotein, Joshua Zhu, Ding Liu, Vy P. Tran, Zhigang Wu, Kuan Jiang, He Zhu, Jiabin Zhang, Christopher Gibbons, Bingzhong Xue, Hang Shi, Peng George Wang
N‑Linked Glycosylation Prevents Deamidation Of Glycopeptide And Glycoprotein, Joshua Zhu, Ding Liu, Vy P. Tran, Zhigang Wu, Kuan Jiang, He Zhu, Jiabin Zhang, Christopher Gibbons, Bingzhong Xue, Hang Shi, Peng George Wang
Faculty Work Comprehensive List
Deamidation has been recognized as a common spontaneous pathway of protein degradation and a prevalent concern in the pharmaceutical industry; deamidation caused the reduction of protein/peptide drug efficacy and shelf life in several cases. More importantly, deamidation of physiological proteins is related to several human diseases and considered a "timer" for the diseases. N-linked glycosylation has a variety of significant biological functions, and it interestingly occurs right on the deamidation site-asparagine. It has been perceived that N-glycosylation could prevent deamidation, but experimental support is still lacking for clearly understanding the role of N-glycosylation on deamidation. Our results presented that deamidation …
Aldol Condensations And Nitrile Aldol Reactions Mediated By Trimethylsilyl Trifluoromethanesulfonate, Samuel R. Bottum
Aldol Condensations And Nitrile Aldol Reactions Mediated By Trimethylsilyl Trifluoromethanesulfonate, Samuel R. Bottum
Honors Theses
In the presence of excess trimethylsilyl trifluoromethanesulfonate (TMSOTf), ketones and esters undergo aldol addition and dehydration to yield chalcones and cinnamates. This one-pot reaction proceeds through in situ enol silane formation, avoiding the need to pre-form and purify the nucleophile in the Mukaiyama aldol reaction. The stoichiometry of the TMSOTf controls whether the reaction proceeds with simple addition or addition-dehydration. When (trimethylsilyl) acetonitrile is stirred with an aldehyde and TMSOTf, nitrile aldol addition is observed.
Design Of New Ruthenium Complexes For Photoactivated Chemotherapy, Lindsey Paul
Design Of New Ruthenium Complexes For Photoactivated Chemotherapy, Lindsey Paul
Honors Theses
Photoactivated chemotherapy (PACT) offers a targeted approach to cancer treatment through selective drug activation. Substitutionally labile ruthenium-based prodrugs undergo ligand-loss when irradiated, producing an unbound ligand and a Ru-aqua complex. We report the synthesis and cytotoxicity of several new ruthenium-centered complexes and their irradiation products for use in PACT. A series of complexes were synthesized in order to study the effects of structural differences on cell viability. Cell viability was tested on T47D human breast cancer cells in the presence of compound to determine cytotoxicity and dose-response. While neither the Rucomplexes nor their ligands demonstrated cytotoxicity, their Ru-aqua dissociation complexes …
Novel Bodipy-Bridged Cyclotriphosphazenes, Hande Eserci̇, Ezel Öztürk, Eli̇f Okutan
Novel Bodipy-Bridged Cyclotriphosphazenes, Hande Eserci̇, Ezel Öztürk, Eli̇f Okutan
Turkish Journal of Chemistry
Three new 2-component unsubstituted (4P), diiodo- (5P), and dibromo- (6P) distyryl-BODIPY-bridged cyclotriphosphazene dimers were designed and synthesized. The newly synthesized BODIPY-cyclotriphosphazene systems were characterized by $^{1}$H, $^{13}$C, and $^{31}$P NMR spectroscopy. The photophysical properties of the distryl-BODIPYs (4-6) and BODIPY-cyclotriphosphazene dyads (4P-6P) were studied by UV-Vis absorption and fluorescence emission spectroscopy. In these derivatives, the bino-type cyclotriphosphazene derivative bearing unsubstituted BODIPY unit 4 P exhibited high fluorescence and no singlet oxygen generation due to the lack of spin converter. The attachment of heavy atoms (iodine and bromine) enabled the production of singlet oxygen. The bino-type BODIPY-cyclotriphosphazenes (5P and 6P) were …
Multiwall Carbon Nanotube-Supported Molybdenum Catalysts For Ammonia Decomposition Reaction Under Microwave Effect, Meli̇h Güler, Di̇lek Varişli
Multiwall Carbon Nanotube-Supported Molybdenum Catalysts For Ammonia Decomposition Reaction Under Microwave Effect, Meli̇h Güler, Di̇lek Varişli
Turkish Journal of Chemistry
In this study, microwave-assisted ammonia decomposition reaction was investigated over molybdenum incorporated catalysts. Due to the selective, volumetric, and noncontact heating properties of the microwave system, higher conversion values could be achieved at relatively lower reaction temperatures, which is important for on-site COx-free hydrogen production. Multiwall carbon nanotube-supported molybdenum catalysts were prepared following the impregnation procedure with different metal loading (3.5%-12.5% wt%), and inductively coupled plasma, nitrogen physisorption, X-ray diffraction, and transmission electron microscopic techniques were employed to characterize the fresh and used samples. Reaction experiments were performed under the flow of pure ammonia with a gas hourly space velocity …
Proline-Based Organocatalyst-Mediated Asymmetric Aldol Reaction Of Acetone With Substituted Aromatic Aldehydes: An Experimental And Theoretical Study, Nevi̇n Arslan, Selami̇ Ercan, Necmetti̇n Pi̇ri̇nççi̇oğlu
Proline-Based Organocatalyst-Mediated Asymmetric Aldol Reaction Of Acetone With Substituted Aromatic Aldehydes: An Experimental And Theoretical Study, Nevi̇n Arslan, Selami̇ Ercan, Necmetti̇n Pi̇ri̇nççi̇oğlu
Turkish Journal of Chemistry
This work involves a facile synthesis of three (S)-proline-based organocatalysts with C$_{2}$ symmetry and their effects in enantioselective aldol reaction of acetone with substituted aromatic aldehydes. Moderate enantioselectivities (up to 61% ee) were obtained depending on the nature of the substituents on the aryl ring. Computational calculations at HF/6-31 + G(d) level were employed to underline the enantioselectivity imposed by all the organocatalysts. Higher calculations at B3LYP/6-311 ++ G(d,p) scrf=(solvent=dichloromethane)//B3LYP/6-31 + G(d) levels of theory were also performed for the aldol reaction of acetone with benzaldehyde and 4-nitrobenzaldehyde catalyzed by 1. The computationaloutcomeswereconsistentwiththoseproducedbyexperimentalresultsandtheywerevaluabletoelucidate the mechanism for the observed stereoselectivity.
Preparation And Catalytic Evaluation Of Au/ Γ-Al2o3nanoparticles For The Conversion Of 4-Nitrophenol To 4-Aminophenol By Spectrophotometric Metho, Farhat Saira, Naveeda Firdous, Rumana Qureshi, Ayesha Ihsan
Preparation And Catalytic Evaluation Of Au/ Γ-Al2o3nanoparticles For The Conversion Of 4-Nitrophenol To 4-Aminophenol By Spectrophotometric Metho, Farhat Saira, Naveeda Firdous, Rumana Qureshi, Ayesha Ihsan
Turkish Journal of Chemistry
A set of catalysts having gold nanoparticles deposited on γ-Al$_{2}$O$_{3}$ ( Au/ γ-Al2O3) with lowest effective amount of gold content were prepared by successive impregnation and hydrogen reduction method. The structural featuresof prepared catalysts were analysed byX-ray diffraction(XRD), N2 physisorption, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR). The catalytic activity was evaluated for the reduction of an organic pollutant 4-nitrophenol (4NP) to 4-aminophenol (4AP) by spectrophotometric analysis. Supported catalyst presented excellent catalytic ability to convert 4NP to 4AP in the presence of sodium borohydride (SBH) due to synergistic effect of Au NPs and mesoporous γ-Al$_{2}$O$_{3}$ support. The reduction …
Box-Behnken Design For Removal Of Uranium(Vi) From Aqueous Solution Using Poly(Ethylene Glycol) Based Dicationic Ionic Liquid Impregnated Chitosan, Süleyman İnan, Taşkin Mumcu, Serap Seyhan Bozkurt
Box-Behnken Design For Removal Of Uranium(Vi) From Aqueous Solution Using Poly(Ethylene Glycol) Based Dicationic Ionic Liquid Impregnated Chitosan, Süleyman İnan, Taşkin Mumcu, Serap Seyhan Bozkurt
Turkish Journal of Chemistry
Poly(ethylene glycol) bis(methylimidazolium) di[bis(trifluoromethylsulfonyl)imide] was synthesized as an ionic liquid and impregnated onto chitosan. The removal of uranium(VI) ions from aqueous solution was investigated with batch sorption tests using ionic liquid impregnated chitosan. Response surface methodology based on 3 level Box-Behnken design was applied to analyze the effect of initial pH (4-6), initial concentration (20-60 mg L$^{-1})$, contact time (15-105 min), and temperature (30-50 $^{\circ}$C C) on the uptake capacity of uranium(VI). Main effect of initial concentration, quadratic effect of contact time, and dual effect of initial pH and contact time were found statistically significant based on analysis of variance …
New Protocols For The Synthesis Of 5-Amino-7-(4-Phenyl)-4,7-Dihydro-[1,2,4]Triazolo[1,5-A]Pyrimidine-6-Carboxylate Esters Using An Efficient Additive, Nader Ghaffari Khaligh, Taraneh Mihankah, Salam Titinchi, Zohreh Shahnavaz, Mohd Rafie Johan
New Protocols For The Synthesis Of 5-Amino-7-(4-Phenyl)-4,7-Dihydro-[1,2,4]Triazolo[1,5-A]Pyrimidine-6-Carboxylate Esters Using An Efficient Additive, Nader Ghaffari Khaligh, Taraneh Mihankah, Salam Titinchi, Zohreh Shahnavaz, Mohd Rafie Johan
Turkish Journal of Chemistry
This work introduces a new additive named 4,4'-trimethylenedipiperidine for the practical and ecofriendly preparation of ethyl 5-amino-7-(4-phenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-$a$]pyrimidine-6-carboxylate derivatives. This chemical is commercially available and easy to handle. It also possesses a low melting point and a broad liquid range temperature, high thermal stability, and good solubility in water. Based on green chemistry principles, the reaction was performed in a) a mixture of green solvents i.e. water and ethanol (1:1 v/v) at reflux temperature, and b) the additive was liquefied at 65 $^{\circ}$C and the reaction was conducted in the liquid state of the additive. High yields of the desired triazolo-pyrimidines …
A Novel Proton-Exchange Porous Silicon Membrane Production Method For \Textmu Dmfcs, Meltem Gör Bölen, Tevhi̇t Karacali
A Novel Proton-Exchange Porous Silicon Membrane Production Method For \Textmu Dmfcs, Meltem Gör Bölen, Tevhi̇t Karacali
Turkish Journal of Chemistry
This study introduces a new production method to use as a porous silicon-based proton exchange membrane for μDMFCs. In this respect, EIS, fuel crossover test, and fuel cell performance test at the μDMFC sample cell are performed at room temperature on a porous silicon-based membrane that was produced for passive mode μDMFC as a proton exchange membrane. The reason for performing the fuel crossover test is to ensure the silicon opened pores along the silicon wafer and to examine the fuel permeability of the membrane. The fuel crossover test shows that the fuel cell provides energy for about 60 min …
Water Management Improvement In Pem Fuel Cells Via Addition Of Pdms Or Aptespolymers To The Catalyst Layer, Hande Ungan, Ayşe Bayrakçeken Yurtcan
Water Management Improvement In Pem Fuel Cells Via Addition Of Pdms Or Aptespolymers To The Catalyst Layer, Hande Ungan, Ayşe Bayrakçeken Yurtcan
Turkish Journal of Chemistry
Water management is one of the obstacles in the development and commercialization of proton exchange membrane fuel cells (PEMFCs). Sufficient humidification of the membrane directly affects the PEM fuel cell performance. Therefore, 2 different hydrophobic polymers, polydimethylsiloxane (PDMS) and (3-Aminopropyl) triethoxysilane (APTES), were tested at different percentages (5, 10, and 20 wt.%) in the catalyst layer. The solution was loaded onto the surface of a 25 BC gas diffusion layer (GDL) via the spraying method. The performance of the obtained fuel cells was compared with the performance of the commercial catalyst. Characterizations of each surface, including different amounts of PDMS …
Preparation Of Different Thin Film Catalysts By Direct Current Magnetron Sputtering Forhydrogen Generation, Gamze Bozkurt, Abdulkadi̇r Özer, Ayşe Bayrakçeken Yurtcan
Preparation Of Different Thin Film Catalysts By Direct Current Magnetron Sputtering Forhydrogen Generation, Gamze Bozkurt, Abdulkadi̇r Özer, Ayşe Bayrakçeken Yurtcan
Turkish Journal of Chemistry
In this study, thin films of Co, Ni, Pd, and Pt were prepared on Co$_{3}$O$_{4}$ support material in pellet form using the direct current (DC) magnetron sputtering method for use as catalysts for hydrogen generation from NaBH4.Characterization of the catalysts was carried out using X-ray diffraction (XRD), scanning electronic microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). According to cross-sectional SEM images, catalyst thicknesses were observed in the range of approximately 115.3-495.8 nm. The particle sizes were approximately 25.0, 21.4, 33.9, and 9.5 nm for Ni-Co$_{3}$O$_{4}$, Co-Co$_{3}$O$_{4}$, Pd-Co$_{3}$O$_{4}$, and Pt-Co$_{3}$O$_{4}$ catalysts, respectively. The increase in NaOH initial concentration provides an increase …
Magnetite Nanoparticles-Based Hydroxyl Radical Scavenging Activity Assay Ofantioxidants Using N, N-Dimethyl-P-Phenylenediamine Probe, Zi̇ya Can, Büşra Keski̇n, Ayşem Arda, Erol Erçağ, Mustafa Reşat Apak
Magnetite Nanoparticles-Based Hydroxyl Radical Scavenging Activity Assay Ofantioxidants Using N, N-Dimethyl-P-Phenylenediamine Probe, Zi̇ya Can, Büşra Keski̇n, Ayşem Arda, Erol Erçağ, Mustafa Reşat Apak
Turkish Journal of Chemistry
Excessive amounts of reactive oxygen species (ROS), unless counterbalanced by antioxidants, can cause cellular damage under oxidative stress conditions; therefore, antioxidative defenses against ROS must be measured. With the development of nanotechnology, nanoparticles have found numerous applications in science, health, and industries. Magnetite nanoparticles (Fe$_{3}$O$_{4}$:MNPs) have attracted attention because of their peroxidase-like activity. In this study, hydroxyl radicals (?OH) generated by MNPs-catalyzed degradation of H$_{2}$O$_{2}$ converted the N,N-dimethyl-p-phenylenediamine (DMPD) probe into its colored DMPD$^{•+}$ radical cation, which gave an absorbance maximum at λ = 553 nm. In the presence of antioxidants, $^{•}$OH was partly scavenged by antioxidants and produced less …
Mathematical Modeling Of A Continuous-Flow Packed-Bed Reactor With Immobilizedlipase For Kinetic Resolution Of (R,S)-2-Pentanol, Asli Soyer Malyemez, Abdulwahap Giwa, Emi̇ne Bayraktar, Ülkü Mehmetoğlu
Mathematical Modeling Of A Continuous-Flow Packed-Bed Reactor With Immobilizedlipase For Kinetic Resolution Of (R,S)-2-Pentanol, Asli Soyer Malyemez, Abdulwahap Giwa, Emi̇ne Bayraktar, Ülkü Mehmetoğlu
Turkish Journal of Chemistry
In this study, the kinetic resolution of (R,S)-2-pentanol via transesterification to achieve S-2-pentanol, a key intermediate required in the synthesis of anti-Alzheimer drugs, was investigated in continuous-flow packed-bed reactors. The effects of residence time, substrate concentration, and operation time of the enzyme were investigated. Under steady state conditions, 50% conversion and enantiomeric excess of the substrate (ee$_{S}$)>99% were achieved at a residence time of 0.04 min. Productivity of the continuous-flow process (1.341 mmol/min/g)was about 4 times higher than that of the corresponding batch process (0.363 mmol/min/g). In addition, the mathematical modeling of the packed-bed reactor was conductedusing an axial …
Innovational Combination Of Hetero-Bifunctional N-Peg Quinoline Scaffolds Derivatives With Improved Anticancer Activity Against Breast And Colon Cancer Cell Lines And P-Glycoprotein, Cytochrome P450 Enzyme Activity Prediction, Mahesh Gaidhane, Ajay Ghatole, Kushal Lanjewar, Kishor Hatzade
Innovational Combination Of Hetero-Bifunctional N-Peg Quinoline Scaffolds Derivatives With Improved Anticancer Activity Against Breast And Colon Cancer Cell Lines And P-Glycoprotein, Cytochrome P450 Enzyme Activity Prediction, Mahesh Gaidhane, Ajay Ghatole, Kushal Lanjewar, Kishor Hatzade
Turkish Journal of Chemistry
Polyethylene glycol (PEG) is a polymer that is widely used as a carrier for drug delivery systems (DDS). A library of N-PEGylated quinoline derivatives of PEG molecular weight 200 was prepared rapidly after the activation of PEGs using maleic anhydride. Quinoline with a polymer backbone is essential as new material. PEG is a water-soluble nonionic polymer approved by food and drug organizations for medicine applications. Because of its nontoxic grapheme, it is widely utilized in numerous biochemical, cosmetic, pharmaceutical, and industrialized applications. The modern SwissADME is a web tool that stretches free admittance to a pool of hasty, yet solid, …
Effect Of Ph On Lipid Oxidation Of Red Onion Skin Extracts Treated With Washed Tilapia (Oreochromis Niloticus) Muscle Model Systems, Senem Güner, Yavuz Yağiz, Zeynal Topalcengi̇z, Hordur G. Kristinsson, George Baker, Paul Sarnoski, Bruce A. Welt, Amarat Simonne, Maurice M. Marshall
Effect Of Ph On Lipid Oxidation Of Red Onion Skin Extracts Treated With Washed Tilapia (Oreochromis Niloticus) Muscle Model Systems, Senem Güner, Yavuz Yağiz, Zeynal Topalcengi̇z, Hordur G. Kristinsson, George Baker, Paul Sarnoski, Bruce A. Welt, Amarat Simonne, Maurice M. Marshall
Turkish Journal of Chemistry
The aim of the study was to investigate the effect of pH on the lipid oxidation of red onion skin extracts (ROSEs) treated with washed tilapia muscle model systems (WTMS). Minced and buffered washed samples were prepared at pH 6.3 and 6.8. The WTMS were treated with2 different concentrations of red onion skin prior to storage for 5 days. Lipid oxidation was investigated via peroxide values (PVs), thiobarbituric acid reactive substances (TBARS), and the formation of volatile compounds. Fatty acid profiles of the samples were also identified. The ROSEs were able to significantly suppress the PV (~71%) and TBARS (~42%) …
Synthesis And Electrochemical Properties Of Copper(Ii), Manganese(Iii) Phthalocyanines Bearing Chalcone Groups At Peripheral Or Nonperipheral Positions, Hüseyi̇n Baş, Nuran Kahri̇man, Zekeri̇ya Biyiklioğlu
Synthesis And Electrochemical Properties Of Copper(Ii), Manganese(Iii) Phthalocyanines Bearing Chalcone Groups At Peripheral Or Nonperipheral Positions, Hüseyi̇n Baş, Nuran Kahri̇man, Zekeri̇ya Biyiklioğlu
Turkish Journal of Chemistry
In this study, new chalcone compound 1, new phthalonitrile derivatives 2 and 3, new copper(II), manganese(III) phthalocyanines bearing chalcone groups at peripheral or nonperipheral positions were synthesized. Electrochemistry of tetra-(4- {(2E)-3-[2-fluoro-4-(trifluoromethyl)phenyl]prop-2-enoyl}phenoxy) substituted Co(II)Pc and Mn(III)Pcs were studied with cyclic voltammetry (CV) to determine the redox properties of the phthalocyanines. According to the results, while the CuPcs 2a and 3a showed two Pc based reduction reactions and one Pc based oxidation reaction, MnPcs 2b and 3b gave two metal-based reduction reactions. All the redox processes are shifted toward positive potentials as a result of the increased electron-withdrawing ability of the trifluoromethyl …
Comparison Of Antioxidant Capacities And Antioxidant Components Of Commercial Bitter Melon (Momordica Charantia L.) Products, Esi̇n Akyüz, Sercan Türkoğlu, Kevser Sözgen Başkan, Esma Tütem, Mustafa Reşat Apak
Comparison Of Antioxidant Capacities And Antioxidant Components Of Commercial Bitter Melon (Momordica Charantia L.) Products, Esi̇n Akyüz, Sercan Türkoğlu, Kevser Sözgen Başkan, Esma Tütem, Mustafa Reşat Apak
Turkish Journal of Chemistry
In this study, the total phenolic contents and total antioxidant capacities of some commercial bitter melon products (powder, packaged powder, capsule, paste in olive oil), and of unripe and ripe fruits were determined by spectrophotometric and chromatographic methods. The total antioxidant capacities of unripe and ripe bitter melon samples, determined by using the CUPRAC (cupric reducing antioxidant capacity assay) and ABTS (2,2'-Azinobis-(3-Ethylbenzthiazolin-6-Sulfonic Acid)/HRP (horseradish peroxidase) methods, were 42.5 and 36.3 μmol TRE (Trolox equivalent) g-1, and 8.7 and 7.0 μmol TRE g-1, respectively. The TAC (total antioxidant capacity) order of the studied samples using the same 2 methods were determined …