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2020

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Articles 14491 - 14520 of 15207

Full-Text Articles in Physical Sciences and Mathematics

Flowerlike Hybrid Horseradish Peroxidase Nanobiocatalyst For The Polymerization Of Guaiacol, Ersen Göktürk Jan 2020

Flowerlike Hybrid Horseradish Peroxidase Nanobiocatalyst For The Polymerization Of Guaiacol, Ersen Göktürk

Turkish Journal of Chemistry

In this study, the catalytic activity and stability of flowerlike hybrid horseradish peroxidase (HRP) nanobiocatalyst (HRP-Cu$^{2+}$) obtained from Cu$^{2+}$ ions and HRP enzyme in the polymerization reaction of guaiacol were analyzed. We demonstrated that HRP-Cu$^{2+}$ and hydrogen peroxide (H$_{2}$O$_{2}$) initiator showed significantly increased catalytic activity and stability on the polymerization of guaiacol compared to that of free HRP enzyme. Poly(guaiacol) was observed with quite high yields (88%) and molecular weights (38,000 g/mol) under pH 7.4 phosphate-buffered saline (PBS) conditions at 60 °C with 5 weight% of HRP-Cu$^{2+}$ loading. HRP-Cu$^{2+}$ also shows very high thermal stability and works even at 70 …

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Determination Of Blood Glucose Parameter From Human Blood Serum By Using A Quartzcrystal Microbalance Sensor Coated With Phthalocyanines Compounds, Evi̇n Şahi̇n Sadik, Hamdi̇ Meli̇h Saraoğlu, İlke Gürol, Mehmet Ali̇ Ebeoğlu, Fatma Emel Koçak Jan 2020

Determination Of Blood Glucose Parameter From Human Blood Serum By Using A Quartzcrystal Microbalance Sensor Coated With Phthalocyanines Compounds, Evi̇n Şahi̇n Sadik, Hamdi̇ Meli̇h Saraoğlu, İlke Gürol, Mehmet Ali̇ Ebeoğlu, Fatma Emel Koçak

Turkish Journal of Chemistry

Determining the blood glucose level is important for the prevention and treatment of diabetes mellitus. We developed a sensor system using Quartz Crystal Microbalance (QCM) to determine the blood glucose level from human blood serum. This study consists of two experimental stages: artificial glucose/pure water solution tests and human blood serum tests. In the first stage of the study, the QCM sensor with the highest performance was identified using artificial glucose solution concentrations. In the second stage of the study, human blood serum measurements were performed using QCM to determine blood glucose levels. QCM sensors were coated with phthalocyanines (Pcs) …

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Preparation Of Different Thin Film Catalysts By Direct Current Magnetron Sputtering Forhydrogen Generation, Gamze Bozkurt, Abdulkadi̇r Özer, Ayşe Bayrakçeken Yurtcan Jan 2020

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 …

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Artificial Intelligence-Based Models For The Qualitative And Quantitative Prediction Of Aphytochemical Compound Using Hplc Method, Abdullahi Garba Usman, Seli̇n Işik, Sani Isah Abba, Fi̇li̇z Meri̇çli̇ Jan 2020

Artificial Intelligence-Based Models For The Qualitative And Quantitative Prediction Of Aphytochemical Compound Using Hplc Method, Abdullahi Garba Usman, Seli̇n Işik, Sani Isah Abba, Fi̇li̇z Meri̇çli̇

Turkish Journal of Chemistry

Isoquercitrin is a flavonoid chemical compound that can be extracted from different plant species such as Mangifera indica (mango), Rheum nobile, Annona squamosal, Camellia sinensis (tea), and coriander (Coriandrum sativum L.). It possesses various biological activities such as the prevention of thromboembolism and has anticancer, antiinflammatory, and antifatigue activities. Therefore, there is a critical need to elucidate and predict the qualitative and quantitative properties of this phytochemical compound using the high performance liquid chromatography (HPLC) technique. In this paper, three different nonlinear models including artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and support vector machine (SVM),in addition to …

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The Production Of Enantiomerically Pure 1-Phenylethanol By Enzymatic Kineticresolution Method Using Response Surface Methodology, Ayşe Bozan, Rahi̇me Songür, Ülkü Mehmetoğlu Jan 2020

The Production Of Enantiomerically Pure 1-Phenylethanol By Enzymatic Kineticresolution Method Using Response Surface Methodology, Ayşe Bozan, Rahi̇me Songür, Ülkü Mehmetoğlu

Turkish Journal of Chemistry

As the enantiomers of 1-phenylethanol are valuable intermediates in several industries, the lipase catalyzed kinetic resolution of (R,S) -1-phenylethanol is a relevant research topic. In this study, the goal was to determine the optimum reaction parameters to produce enantiomerically pure 1-phenylethanol by lipase (Novozyme 435) catalyzed kinetic resolution using response surface methodology (RSM). Reactions were performed with 40-400 mM (R,S)-1-phenylethanol, 120-1200 mM vinyl acetate and 2-22 mg/ mL biocatalyst concentrations (BC$_{L}$), at 20-60 °C and with a stirring rate of 50-400 rpm for 5-120 min. The samples were analyzed using high performance liquid chromatography (HPLC) with a Chiralcel OB column. …

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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 Jan 2020

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 …

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Application Of Synthesized Copper Nanoparticles Using Aqueous Extract Ofziziphus Mauritiana L. Leaves As A Colorimetric Sensor For The Detection Of Ag$^{+}$, Roomia Memon, Ayaz Ali Memon, Syed Tufail Hussain Sherazi, Siraj Uddin, Aamna Balouch, Muhammad Raza Shah, Sarfaraz Ahmed Mahesar, Kauser Rajar, Muhammad Hassan Agheem Jan 2020

Application Of Synthesized Copper Nanoparticles Using Aqueous Extract Ofziziphus Mauritiana L. Leaves As A Colorimetric Sensor For The Detection Of Ag$^{+}$, Roomia Memon, Ayaz Ali Memon, Syed Tufail Hussain Sherazi, Siraj Uddin, Aamna Balouch, Muhammad Raza Shah, Sarfaraz Ahmed Mahesar, Kauser Rajar, Muhammad Hassan Agheem

Turkish Journal of Chemistry

The presented work demonstrates the preparation of copper nanoparticles (CuNPs) via aqueous leaves extract of Ziziphus mauritiana L. (Zm) using hydrazine as a reducing agent. Various parameters such as volume of extract, concentration of hydrazine hydrate, concentration of copper chloride, and pH of the solution were optimized to obtain Ziziphus mauritiana L. leaves extract derived copper nanoparticles (Zm-CuNPs). Brownish red color was initial indication of the formation of Zm-CuNPs while it was confirmed by surface plasmon resonance (SPR) band at wavelength of 584 nm using ultraviolet-visible (UV-vis) spectroscopy. Synthesized Zm-CuNPs were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron …

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An Efficient Approach For The Synthesis Of Novel Methyl Sulfones In Acetic Acid Mediumand Evaluation Of Antimicrobial Activity, Gollapudi Ravi Kumar, Chandra Rao Dasireddy, Ravi Varala, Vijay Kotra, Hari Babu Bollikolla Jan 2020

An Efficient Approach For The Synthesis Of Novel Methyl Sulfones In Acetic Acid Mediumand Evaluation Of Antimicrobial Activity, Gollapudi Ravi Kumar, Chandra Rao Dasireddy, Ravi Varala, Vijay Kotra, Hari Babu Bollikolla

Turkish Journal of Chemistry

A series of nine methyl sulphones (3a-3i) starting from the aldehydes (1a-1i) were synthesized in two consecutive steps. In the first step, preparation of allyl alcohols (2a-2i) from their corresponding aldehydes by the reaction of sodium borohydride in methanol at room temperature is reported. Finally, methyl sulphones are synthesized by condensing sodium methyl sulfinates with allyl alcohols in the presence of BF$_{3}$.Et$_{2}$O in acetic acid medium at room temperature for about 2-3 h. The reaction conditions are simple, yields are high (85%-95%), and the products were obtained with good purity. All the synthesized compounds were characterized by their $^{1}$H, $^{13}$C …

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Synthesis, Characterization And Evaluation Of Antidengue Activity Of Enantiomeric Schiffbases Derived From S-Substituted Dithiocarbazate, Maqsood Maryam, Sang Loon Tan, Karen Ann Crouse, Mohamed Ibrahim Mohamed Tahir, Hui Yee Chee Jan 2020

Synthesis, Characterization And Evaluation Of Antidengue Activity Of Enantiomeric Schiffbases Derived From S-Substituted Dithiocarbazate, Maqsood Maryam, Sang Loon Tan, Karen Ann Crouse, Mohamed Ibrahim Mohamed Tahir, Hui Yee Chee

Turkish Journal of Chemistry

A series of Schiff bases have been successfully synthesized through the acid-catalyzed condensation of S-substituted dithiocarbazates and three enantiomerically pure monoterpenes, (1R)-(+)-camphor, (1S)-(-)-camphor, (1R)-(-)-camphorquinone, (1S)- (+)-camphorquinone, (R)-(-)-carvone and (S)-(+)-carvone. Spectroscopic results revealed that the Schiff bases containing camphor or carvone likely adopted an E-configuration along the characteristic imine bond while those containing camphorquinone assumed a Z-configuration. The antidengue potential of these compounds was evaluated based on DENV 2 caused cytopathic effect (CPE) reduction-based in vitro evaluation. The compounds were validated through secondary foci forming unit reduction assay (FFURA). Compounds were also tested for their cytotoxicity against Vero cells. The compounds …

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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 Jan 2020

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 …

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Synthesis And Structural Analysis Of Nonstoichiometric Ternary Fulleride K1.5ba0.25csc60, Havva Esma Okur Kutay Jan 2020

Synthesis And Structural Analysis Of Nonstoichiometric Ternary Fulleride K1.5ba0.25csc60, Havva Esma Okur Kutay

Turkish Journal of Chemistry

The existence of cation-vacancy sites in fullerides might lead to long-range ordering and generate a new vacancy-ordered superstructure. The purpose of this work is to search whether or not long-range ordering of vacant tetrahedral sites, namely superstructure emerges in nonstoichiometric K1.5Ba0.25CsC60 fulleride. Therefore, K1.5Ba0.25CsC60 with cation-vacancy sites is synthesized using a precursor method to avoid inadequate stoichiometry control and formation of impurity phases within the target composition. For this purpose, first, phase-pure K6C60, Ba6C60 and Cs6C60 precursors are synthesized. Stoichiometric quantities of these precursors are used for further reaction with C60 to afford K1.5Ba0.25CsC60. Rietveld analysis of the high-resolution synchrotron …

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Synthesis And Characterization Of Hexagonal Boron Nitride Used For Comparison Of Removal Of Anionic And Cationic Hazardous Azo-Dye: Kinetics And Equilibrium Studies, Tuba Tarhan Jan 2020

Synthesis And Characterization Of Hexagonal Boron Nitride Used For Comparison Of Removal Of Anionic And Cationic Hazardous Azo-Dye: Kinetics And Equilibrium Studies, Tuba Tarhan

Turkish Journal of Chemistry

The purpose of this study was to compare the adsorption behavior of cationic and anionic dyes onto a hexagonal boron nitride (hBN) nanostructure that was rich in a negative charge. Herein, the hBN nanostructure was synthesized using boric acid as a precursor material. The characteristic peaks of the hBN nanostructure were performed using Fourier transform infrared (FT-IR) and Raman spectroscopies. The morphology and the particle size of hBN nanostructure were determined by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). During the studies, various essential adsorption parameters were investigated, such as the initial dye concentration, pH of the dye …

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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 Jan 2020

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, …

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Catalytic Activity Of Novel Thermoplastic/Cellulose-Au Nanocomposites Prepared By Cryomilling, Joanna Kwiczak Yigitbasi Jan 2020

Catalytic Activity Of Novel Thermoplastic/Cellulose-Au Nanocomposites Prepared By Cryomilling, Joanna Kwiczak Yigitbasi

Turkish Journal of Chemistry

Due to environmental concerns, increasing attention has been focused on the application and preparation of biobased polymers and their blends. In this study, cellulose, the most spread biopolymer on Earth, was used in the preparation of novel cotton/polypropylene- Au and cotton/polyethylene-Au nanocomposites via a green mechanochemical approach. First, mechanoradicals were generated by ball milling of the cotton and thermoplastics under cryo conditions, and then, these radicals were used in the reduction of Au ions to Au nanoparticles (Au NPs). Nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The application of mechanochemistry in …

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Effective Synthesis Of Bicyclodienes Via Palladium-Catalyzed Asymmetric Allylic Alkylationand Ruthenium-Catalyzed Cycloisomerization, Ni̇zam Havare Jan 2020

Effective Synthesis Of Bicyclodienes Via Palladium-Catalyzed Asymmetric Allylic Alkylationand Ruthenium-Catalyzed Cycloisomerization, Ni̇zam Havare

Turkish Journal of Chemistry

[n.3.0]Bicycles (n = 3-6) can be synthesized using palladium-catalyzed asymmetric allylic alkylation followed by rutheniumcatalyzed cycloisomerization. New types of triarylphosphino-1,2-diaminooxazoline ligands show the same high levels of enantioselectivity observed with Trost ligand when employed in Pd-catalyzed allylic alkylation reactions. The enyne products of these allylic alkylation reactions were further elaborated using a Ru-catalyzed redox isomerization process, for which a mechanism is proposed.

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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 Jan 2020

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%) …

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Chemical Composition, And Antibacterial And Antioxidant Activities Of Essential Oils From Laggera Tomentosa Sch. Bip. Ex Oliv. Et Hiern (Asteraceae), Tokuma Getahun, Vinit Sharma, Deepak Kumar, Neeraj Gupta Jan 2020

Chemical Composition, And Antibacterial And Antioxidant Activities Of Essential Oils From Laggera Tomentosa Sch. Bip. Ex Oliv. Et Hiern (Asteraceae), Tokuma Getahun, Vinit Sharma, Deepak Kumar, Neeraj Gupta

Turkish Journal of Chemistry

Laggera tomentosa Sch. Bip. ex Oliv. et Hiern (Asteraceae), an endemic Ethiopian medicinal plant, is traditionally used to treat various ailments. Previously, the chemical constituents of the essential oil (EO) of its leaves and inflorescence were documented. However, no data about the chemical compositions of other parts of the EOs of the plant have been reported to date. Moreover, there are no previous biological activity reports on any parts of the EOs of this plant. Thus, in this study, the EOs were isolated from the stem bark and roots of this plant by hydrodistillation and analyzed using gas chromatography-mass spectrometry …

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Synthesis And Electrochemical Properties Of Copper(Ii), Manganese(Iii) Phthalocyanines Bearing Chalcone Groups At Peripheral Or Nonperipheral Positions, Hüseyi̇n Baş, Nuran Kahri̇man, Zekeri̇ya Biyiklioğlu Jan 2020

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 …

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Newly Synthesized Peripherally Octa-Substituted Zinc Phthalocyanines Carrying Halogenterminated Phenoxy-Phenoxy Moiety: Comparative Photochemical And Photophysicalfeatures, Erkan Kirbaç, Ali̇ Erdoğmuş Jan 2020

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 …

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Evaluation Of Carbonic Anhydrase And Paraoxonase Inhibition Activities And Molecular Docking Studies Of Highly Water-Soluble Sulfonated Phthalocyanines, Emre Güzel, Fati̇h Sönmez, Sultan Erkan, Kübra Çikrikci, Adem Ergün, Nahi̇t Gençer, Oktay Arslan, Makbule Koçak Jan 2020

Evaluation Of Carbonic Anhydrase And Paraoxonase Inhibition Activities And Molecular Docking Studies Of Highly Water-Soluble Sulfonated Phthalocyanines, Emre Güzel, Fati̇h Sönmez, Sultan Erkan, Kübra Çikrikci, Adem Ergün, Nahi̇t Gençer, Oktay Arslan, Makbule Koçak

Turkish Journal of Chemistry

The investigation of carbonic anhydrase and paraoxonase enzyme inhibition properties of water-soluble zinc and gallium phthalocyanine complexes (1 and 2) are reported for the first time. The binding of p-sulfonylphenoxy moieties to the phthalocyanine structure favors excellent solubilities in water, as well as providing an inhibition effect on carbonic anhydrase (CA) I and II isoenzymes and paraoxonase (PON1) enzyme. According to biological activity results, both complexes inhibited hCA I, hCA II, and PON1. Whereas 1 and 2 showed moderate hCA I and hCA II (off-target cytosolic isoforms) inhibitory activity (Ki values of 26.09 μM and 43.11 μM for hCA I …

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Computational And Biological Studies Of Novel Thiazolyl Coumarin Derivatives Synthesized Through Suzuki Coupling, Shaista Parveen, Saima Kalsoom, Rifhat Bibi, Ambreen Asghar, Abdul Hameed, Waqar Ahmed, Abbas Hassan Jan 2020

Computational And Biological Studies Of Novel Thiazolyl Coumarin Derivatives Synthesized Through Suzuki Coupling, Shaista Parveen, Saima Kalsoom, Rifhat Bibi, Ambreen Asghar, Abdul Hameed, Waqar Ahmed, Abbas Hassan

Turkish Journal of Chemistry

The current investigation presents the synthesis, computational molecular-docking and biological activity studies of arylated thiazole coumarins. Aryl substituted thiazolyl coumarin derivatives were synthesized via Suzuki cross-coupling reaction. A detailed reaction condition optimization revealed that the Pd-PEPPSI-IPent precatalyst in only 2 mol% loading resulted in the desired product with high yield. The aim of this study was to examine the antimicrobial behavior of thiazole coumarin derivatives through in vitro and in silico studies. All the compounds showed activity against both antibacterial strains, Staphylococcus aureus and Escherichia coli, except 5d. Similarly, the compounds 5a, 5b, and 5d were found to be active …

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Synthesis And Molecular Docking Studies Of Quinoline Derivatives As Hiv Non-Nucleoside Reverse Transcriptase Inhibitors, Nivedita Bhardwaj, Diksha Choudhary, Akashdeep Pathania, Somesh Baranwal, Pradeep Kumar Jan 2020

Synthesis And Molecular Docking Studies Of Quinoline Derivatives As Hiv Non-Nucleoside Reverse Transcriptase Inhibitors, Nivedita Bhardwaj, Diksha Choudhary, Akashdeep Pathania, Somesh Baranwal, Pradeep Kumar

Turkish Journal of Chemistry

Quinoline moiety is an important scaffold in the field of drug discovery and drug development, with a wide range of pharmacological activities. Quinoline derivatives are potent inhibitors for reverse transcriptase, which is responsible for the conversion of single-stranded viral RNA into double-stranded viral DNA.In the present study, we have designed and synthesized 2 series, namely pyrazoline and pyrimidine containing quinoline derivatives as non nucleoside reverse transcriptase inhibitors (NNRTIs). Eleven compounds were synthesized and characterized by 1H and 13C NMR and mass spectrophotometry. The synthesized compounds were also docked on an HIV reverse transcriptase binding site (PDB: 4I2P); most of these …

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Blue Tio2 Nanotube Arrays As Semimetallic Materials With Enhanced Photoelectrochemical Activity Towards Water Splitting, Naeimeh Sadat Peighambardoust, Umut Aydemir Jan 2020

Blue Tio2 Nanotube Arrays As Semimetallic Materials With Enhanced Photoelectrochemical Activity Towards Water Splitting, Naeimeh Sadat Peighambardoust, Umut Aydemir

Turkish Journal of Chemistry

In the past years there has been a great interest in self-doped TiO2 nanotubes (blue TiO2 nanotubes) compared to undoped ones owing to their high carrier density and conductivity. In this study, blue TiO2 nanotubes are investigated as photoanode materials for photoelectrochemical water splitting. Blue TiO2 nanotubes were fabricated with enhanced photoresponse behavior through electrochemical cathodic polarization on undoped and annealed TiO2 nanotubes. The annealing temperature of undoped TiO2 nanotubes was tuned before cathodic polarization, revealing that annealing at 500 °C improved the photoresponse of the nanotubes significantly. Further optimization of the blue TiO2 nanotubes was achieved by adjusting the …

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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 Jan 2020

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 …

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Structural Insights Of Two Novel N-Acetyl-Glucosaminidase Enzymes Through In Silico Methods, Ari̇f Sercan Şahutoğlu, Hati̇ce Duman, Steven Alex Frese, Sercan Karav Jan 2020

Structural Insights Of Two Novel N-Acetyl-Glucosaminidase Enzymes Through In Silico Methods, Ari̇f Sercan Şahutoğlu, Hati̇ce Duman, Steven Alex Frese, Sercan Karav

Turkish Journal of Chemistry

EndoBI-1 and EndoBI-2 are two endo-β-N-acetylglucosaminidase isoenzymes that cleave N-N'-diacetylchitobiosyl moieties found in various types of native N-glycans. These N-glycans are indigestible by human infants and adults due to the lack of responsible glycosyl hydrolases and they act as selective prebiotics for a probiotic microorganism, Bifidobacterium longum subsp. infantis, in the large intestine. The selectivity and the thermostability of EndoBI-1 and EndoBI-2 suggest that these enzymes may be useful for many scientific and industrial applications. In this study, the growing numbers of homologous sequences in different databases were exploited in a comparative approach to investigate structural properties of EndoBI-1 and …

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Highly Luminescent Water-Dispersed Silicon Quantum Dots For Fluorometric Determination Of Oxytetracycline In Milk Samples, Hayri̇ye Eda Şatana Kara, Burak Demi̇rhan, Buket Er Demi̇rhan Jan 2020

Highly Luminescent Water-Dispersed Silicon Quantum Dots For Fluorometric Determination Of Oxytetracycline In Milk Samples, Hayri̇ye Eda Şatana Kara, Burak Demi̇rhan, Buket Er Demi̇rhan

Turkish Journal of Chemistry

A fluorescent probe based on silicon quantum dots (SiQDs) was developed for the selective and sensitive detection of oxytetracycline (OTC) via the inner filter effect (IFE). The water-soluble fluorescent SiQD was synthesized based on the reaction of 3-Aminopropyltriethoxysilane (APTES) and sodium citrate as precursors by the one-pot hydrothermal process. The strong fluorescence emission of quantum dots (QDs) was obtained at 440 nm when excited at 350 nm and OTC had a broad absorption band between 200 and 400 nm. The excitation spectrum of SiQDs was completely overlapped with the absorption spectrum of OTC. The light at an excitation wavelength of …

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Fabrication And Characterization Of Boric Acid-Crosslinked Ethyl Cellulose And Polyvinyl Alcohol Films As Potential Drug Release Systems For Topical Drug Delivery, Nasrin Aliasgharlou, Farzin Asghari Sana, Saba Khoshbakht, Pezhman Zolfaghari, Hamed Charkhian Jan 2020

Fabrication And Characterization Of Boric Acid-Crosslinked Ethyl Cellulose And Polyvinyl Alcohol Films As Potential Drug Release Systems For Topical Drug Delivery, Nasrin Aliasgharlou, Farzin Asghari Sana, Saba Khoshbakht, Pezhman Zolfaghari, Hamed Charkhian

Turkish Journal of Chemistry

In this study, boric acid (BA) is employed as a crosslinking agent to improve the characteristics of two commonly used polymeric films, ethyl cellulose (EC) and polyvinyl alcohol (PVA), for topical drug delivery applications. The developed films are characterized by FTIR spectroscopy and SEM analysis. The results show that the surfaces of the prepared films are even and transparent, except for the BA-modified EC sample. The initial cumulative release for erythromycin (EM) is found to be 0.30 and 0.36 mg/mL for EC and PVA films, which drops to 0.25 and 0.20 mg/mL after BA crosslinking, respectively, after 1 h at …

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Synthesis, Antioxidant And Antimicrobial Properties Of Novel Pyridyl-Carbonyl Thiazoles As Dendrodoine Analogs, Zafer Şahi̇n, Sevde Nur Bi̇lteki̇n, Leyla Yurttaş, Şeref Demi̇rayak Jan 2020

Synthesis, Antioxidant And Antimicrobial Properties Of Novel Pyridyl-Carbonyl Thiazoles As Dendrodoine Analogs, Zafer Şahi̇n, Sevde Nur Bi̇lteki̇n, Leyla Yurttaş, Şeref Demi̇rayak

Turkish Journal of Chemistry

Marine compound dendrodoine was first obtained from tunicate species (Dendrodo grossularia). It has a five-membered ring, namely, it is a heterocycle thiadiazole, which is found rarely in natural sources. Following its biological activities, novel analogs have been investigated recently. Synthesis of the analogs for this study is realized with uncommon thiazole closure, including methylene-carbonyl condensation. Structures are elucidated by NMR (1H, 13C) and HRMS spectrums. As an alkaloid derivative, antioxidant properties were evaluated with DPPH and FRAP assays and antimicrobial effect with microdilution method. Among the series, 3bc-3cf showed higher antioxidant activity than those having 3 or 4-pyridyl substituents. There …

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Active Seismic Studies In Lemon Creek Valley Glacier, Juneau, Alaska: Characterization Of Subglacial Sediments To Understand Glacier Dynamics, Lucia Fernanda Gonzalez Jan 2020

Active Seismic Studies In Lemon Creek Valley Glacier, Juneau, Alaska: Characterization Of Subglacial Sediments To Understand Glacier Dynamics, Lucia Fernanda Gonzalez

Open Access Theses & Dissertations

Deformation and flow properties of subglacial sediments as well as the presence and volume of water at the ice/bed interface strongly influence glacier dynamics. Studies of Lemon Creek Glacier, a small temperate valley glacier in the Juneau Icefield, near Juneau, Alaska, have shown that the glacier is rapidly retreating, with a negative mass balance every year since 1957. However, the bed topography and properties of subglacial sediments at the base of Lemon Creek Glacier remained unknown until now. In this project, we process and interpret ~1-km-long NW-SE trending active-source seismic reflection profiles collected during June and July 2017 near the …

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Residual Control Chart For Binary Response With Multicollinearity Covariates By Neural Network Model, Jong-Min Kim, Ning Wang, Yumin Liu, Kayoung Park Jan 2020

Residual Control Chart For Binary Response With Multicollinearity Covariates By Neural Network Model, Jong-Min Kim, Ning Wang, Yumin Liu, Kayoung Park

Mathematics & Statistics Faculty Publications

Quality control studies have dealt with symmetrical data having the same shape with respect to left and right. In this research, we propose the residual (r) control chart for binary asymmetrical (non-symmetric) data with multicollinearity between input variables via combining principal component analysis (PCA), functional PCA (FPCA) and the generalized linear model with probit and logit link functions, and neural network regression model. The motivation in this research is that the proposed control chart method can deal with both high-dimensional correlated multivariate data and high frequency functional multivariate data by neural network model and FPCA. We show that the neural …

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