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Articles 1441 - 1470 of 2628
Full-Text Articles in Physical Sciences and Mathematics
Properties Of The Mixed Adsorption Layer: Neutral Detergent-Tetramethylthiourea At Interface Electrode/Solution, Jolanta Nieszporek, Dorota Sienko, Dorota Gugala-Fekner, Malgorzata Klin
Properties Of The Mixed Adsorption Layer: Neutral Detergent-Tetramethylthiourea At Interface Electrode/Solution, Jolanta Nieszporek, Dorota Sienko, Dorota Gugala-Fekner, Malgorzata Klin
Turkish Journal of Chemistry
The mixed adsorption layers of tetramethylthiourea and a neutral detergent formed at the electrode surface in 1 M NaClO_4 are described in this paper. The systems were characterized by the measurement of differential capacity, zero charge potential, and surface tension at the same potential. The data were analyzed to obtain the surface pressure and relative surface excess of tetramethylthiourea as a function of electrode charge and bulk concentration of the studied compounds. The values of the lateral interaction parameters, obtained in the presence and in the absence of decanoyl-N-methylglucamide (C_{17}H_{35}NO_6), change differently depending on the isotherm used, but \Delta G° …
Efficient One-Pot Alkylation Of Imines Using Nanosilver Iodide In Aqueous Media, Javad Safaei Ghomi, Ahmad Kakavand-Qalenoei, Mohammad Ali Ghasemzadeh, Masoud Salavati-Niasari
Efficient One-Pot Alkylation Of Imines Using Nanosilver Iodide In Aqueous Media, Javad Safaei Ghomi, Ahmad Kakavand-Qalenoei, Mohammad Ali Ghasemzadeh, Masoud Salavati-Niasari
Turkish Journal of Chemistry
An efficient ecofriendly method for the alkylation reaction of various imines is described by a simple one-pot reaction of aldehydes, amines and alkyl iodides in the presence of AgI nanoparticles in aqueous media. Silver iodide nanoparticles mediated an enhanced rate and facility of reaction and showed high influence in the green synthesis of some amine derivatives. Moreover, this nanoparticle increased the yields of products and decreased the reaction times in all cases. The heterogeneous mediator was fully characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and FT-IR experimental techniques.
Synthesis Of 3-Pyrroline-2-Ones From Amino Acids And An Aryl Amine, Nezi̇re Saygili, Cemi̇l Aydoğan
Synthesis Of 3-Pyrroline-2-Ones From Amino Acids And An Aryl Amine, Nezi̇re Saygili, Cemi̇l Aydoğan
Turkish Journal of Chemistry
The conversion of the amino group of amino dicarboxylicacid esters and an aryl amine into N-substituted pyrrolinone derivatives with dimethoxydihydrofurane is described. The conversion also occurs with serine methylester but it decomposes very quickly.
A Novel Soluble Phthalocyanine Capable Of Binding Four Boronic Esters, Şennur Özçeli̇k, Gülnur Keser Karaoğlan, Gülşah Gümrükçü, Ahmet Gül
A Novel Soluble Phthalocyanine Capable Of Binding Four Boronic Esters, Şennur Özçeli̇k, Gülnur Keser Karaoğlan, Gülşah Gümrükçü, Ahmet Gül
Turkish Journal of Chemistry
A novel Zn phthalocyanine bearing 4 salicylideniminophenyloxy substituents on peripheral positions was synthesized from the reaction of 4-aminophenoxy substituted phthalocyanine and salicylaldehyde. The condensation reaction of salicylidene Schiff base groups and benzeneboronic acid produced a new phthalocyanine carrying benzeneboronic acid ester derivatives as substituents. Ethoxy groups were bound to boronic acid as a second ligand. The presence of B-N bond interactions enhanced the stability of this boronated phthalocyanine derivative, which exhibited sufficient air stability during the purification and characterization processes. The novel compounds were characterized by using elemental analysis, IR, ^1H-NMR, ^{11}B-NMR, ^{13}C-NMR, UV-Vis and MALDI-TOF MS spectral data.
Evaluation Of A Wide Rim Phosphorylated Calix[4]Arene's Properties As A Sensory Molecule In An Er(Iii)-Pvc Membrane Sensor, Abbas Ali Zamani, Massoumeh Parinejad, Fataneh Jamali, Mohammad Reza Yaftian, Dominique Matt
Evaluation Of A Wide Rim Phosphorylated Calix[4]Arene's Properties As A Sensory Molecule In An Er(Iii)-Pvc Membrane Sensor, Abbas Ali Zamani, Massoumeh Parinejad, Fataneh Jamali, Mohammad Reza Yaftian, Dominique Matt
Turkish Journal of Chemistry
This study concerns the evaluation of ionophoric properties of a functionalized calix[4]arene, named 5,17-bis(diphenylphosphinoyl)- 25,26,27,28-tetrapropoxycalix[4]arene (Calix), by its application as a sensing material in an erbium(III)-PVC membrane potentiometric sensor. A membrane formed by 30% PVC, 65% dioctyl phthalate (DOP) as plasticizing solvent mediator, 2% sodium tetraphenyl borate (NaTPB) as ion excluder, and 3% of Calix as ionophore shows the best performance of the sensor. The prepared sensor presents a nearly Nernstian response (a slope of 20.0 \pm 0.5 mV/decade) over a concentration range of 1 \times 10^{-7}--1 \times 10^{-3} M of erbium ions, with a limit of detection of 3.8 …
Preparation, Morphology, And Thermomechanical Properties Of Coal Ash/Polyethylene Oxide Composites, Khalid Saeed, Muhmmad Ishaq, Muhmmad Ilyas
Preparation, Morphology, And Thermomechanical Properties Of Coal Ash/Polyethylene Oxide Composites, Khalid Saeed, Muhmmad Ishaq, Muhmmad Ilyas
Turkish Journal of Chemistry
Coal ash/polyethylene oxide (ash/PEO) composite films were prepared by the solution casting technique. Scanning electron microscopy (SEM) micrographs indicated that the ash particles were dispersed and embedded well within the polymer matrix. The size of the ash particles in the PEO matrix was less than 3 \mu m. The polarized optical microscopic (POM) analyses revealed that the pure PEO, upon crystallization, showed distinct crystalline spherulites of a considerable size. The size of the spherulites was decreased by the incorporation of ash particles into the polymer matrix, which might be due to the nucleation role of ash in ash/PEO composite, and …
Kinetic Spectrophotometric Determination Of Trace Copper(Ii) Ions By Their Catalytic Effect On The Reduction Of Brilliant Cresyl Blue By Ascorbic Acid, Hali̇l İbrahi̇m Ulusoy, Ramazan Gürkan, Mehmet Akçay
Kinetic Spectrophotometric Determination Of Trace Copper(Ii) Ions By Their Catalytic Effect On The Reduction Of Brilliant Cresyl Blue By Ascorbic Acid, Hali̇l İbrahi̇m Ulusoy, Ramazan Gürkan, Mehmet Akçay
Turkish Journal of Chemistry
In the present study, a novel catalytic-kinetic spectrophotometric method was developed for the determination of trace amounts of copper. It is based on the catalytic effect of Cu(II) on the reduction of brilliant cresyl blue (BCB) by ascorbic acid in pH 5.0 acetate buffer medium. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of BCB at 624 nm. The operating conditions regarding concentration of reagents, pH, time, and temperature were established and optimized in detail. The working curve was linear in the concentration range of 0.1-5.0 \mu g L^{-1}. The maximum percentage error and standard deviation for …
Synthesis And Spectrophotometric Determination Of Acidity Constants Of 2,3,4,6'-Tetrahydroxy-3'-Sulfoazobenzene And Their Use In Determination Of Aluminum, Tufan Güray, Cemi̇l Öğreti̇r, Tevfi̇k Gedi̇kbey, Abu Ali̇ Hüseyi̇nli̇
Synthesis And Spectrophotometric Determination Of Acidity Constants Of 2,3,4,6'-Tetrahydroxy-3'-Sulfoazobenzene And Their Use In Determination Of Aluminum, Tufan Güray, Cemi̇l Öğreti̇r, Tevfi̇k Gedi̇kbey, Abu Ali̇ Hüseyi̇nli̇
Turkish Journal of Chemistry
A novel azo derivative, 2,3,4,6'-tetrahydroxy-3'-sulfoazobenzene (THSA), was synthesized by using pyrogallol. The acid dissociation constants, or K_a values, of THSA were determined by the UV-visible spectroscopic technique. The protonation and deprotonation behaviors of the title molecule were studied from the super basic to the super acid region (i.e. 10 N NaOH to 98% H_2SO_4), including the pH region. A selective and sensitive UV-visible spectrophotometric method was devised for determination of aluminum by using this ligand. The developed method was successfully applied to an alunite mineral and to pharmaceutical preparations for the determination of aluminum.
Determination Of Stability Constants Of 5-(2-Hydroxybenzylidene)-2-Thioxodihydropyrimidine-4,6(1h,5h)-Dione With Copper(Ii) And Mercury(Ii) Ions, Morteza Bahram, Nader Noroozi Pesyan, Abdolhossein Naseri, Masomeh Tasbihforosh
Determination Of Stability Constants Of 5-(2-Hydroxybenzylidene)-2-Thioxodihydropyrimidine-4,6(1h,5h)-Dione With Copper(Ii) And Mercury(Ii) Ions, Morteza Bahram, Nader Noroozi Pesyan, Abdolhossein Naseri, Masomeh Tasbihforosh
Turkish Journal of Chemistry
In this work, a hard model chemometric method was used to determine the stability constants of copper(II) and mercury(II) complexes with the newly synthesized ligand 5-(2-hydroxybenzylidene)- 2-thioxodihydropyrimidine-4,6(1H,5H)-dione in acetonitrile by UV-Vis spectrophotometry. The ligand forms stable complexes with both metal cations. The protonation constants of the ligand were also measured in an ethanol-water (1:1) mixture.
Synthesis And Anti-Helicobacter Pylori Activity Of (4-Nitro-1-Imidazolylmethyl)-1,2,4-Triazoles, 1,3,4-Thiadiazoles, And 1,3,4-Oxadiazoles, Asal Fallah-Tafti, Tahmineh Akbarzadeh, Parastoo Saniee, Farideh Siavoshi, Abbas Shafiee, Alireza Foroumadi
Synthesis And Anti-Helicobacter Pylori Activity Of (4-Nitro-1-Imidazolylmethyl)-1,2,4-Triazoles, 1,3,4-Thiadiazoles, And 1,3,4-Oxadiazoles, Asal Fallah-Tafti, Tahmineh Akbarzadeh, Parastoo Saniee, Farideh Siavoshi, Abbas Shafiee, Alireza Foroumadi
Turkish Journal of Chemistry
A series of [(4-nitro-1H-imidazol-1-yl)methyl]-1,2,4- triazoles and 1,3,4-thiadiazoles were prepared and evaluated for their activity against sensitive and resistant H. pylori strains. Study of the structure-activity relationship of these series of compounds indicated that the type of nitroimidazole moiety and the pendent group on the heteroaryl analog dramatically impact the anti-H. pylori activity. In triazole series, compound 5d, containing a 4-methyl phenyl group on the triazole ring, was the most potent compound tested against both metronidazole-sensitive and -resistant strains at a concentration of 8 \mu g.
Synthesis, Characterization, And Biological Activity Studies Of (E)-N'-((Thiophen-2-Yl)Methylene)Benzofuran-2-Carbohydrazide And Its Metal(Ii) Complexes, Madappa B. Halli, Vijayalaxmi B. Patil, Sumathi R. Bevinamarada
Synthesis, Characterization, And Biological Activity Studies Of (E)-N'-((Thiophen-2-Yl)Methylene)Benzofuran-2-Carbohydrazide And Its Metal(Ii) Complexes, Madappa B. Halli, Vijayalaxmi B. Patil, Sumathi R. Bevinamarada
Turkish Journal of Chemistry
Metal complexes of the type MLX_2, where M = Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II), and X = Cl and L = TMBC, Schiff base derived from the condensation of benzofuran-2-carbohydrazide with thiophene-2-aldehyde were synthesized. The structure of the complexes was proposed in light of analytical, IR, UV-Vis, ^1H-NMR, FAB-MS, ESR spectral data, and magnetic studies. The complexes were soluble in DMF and DMSO. The measured molar conductance values indicated that the complexes were nonelectrolytic in nature. On the basis of these studies, 6 coordinated octahedral polymeric structures were assigned to the Co(II), Ni(II), and Cu(II) complexes, and 4 …
Voltammetric Behavior Of Indole-3-Acetic Acid And Kinetin At Pencil-Lead Graphite Electrode And Their Simultaneous Determination In The Presence Of Anionic Surfactant, Yavuz Yardim, Zühre Şentürk
Voltammetric Behavior Of Indole-3-Acetic Acid And Kinetin At Pencil-Lead Graphite Electrode And Their Simultaneous Determination In The Presence Of Anionic Surfactant, Yavuz Yardim, Zühre Şentürk
Turkish Journal of Chemistry
A method was developed for the simultaneous determination of indole-3-acetic acid (IAA) and kinetin, based on the oxidation of both phytohormones at a pencil-lead graphite electrode. The electrochemical behaviors were examined by cyclic, linear sweep, and square-wave voltammetry in the pH range of 2-12. In Britton-Robinson buffer solution (pH 6), the oxidation peaks of IAA and kinetin are well separated by square-wave voltammetry. By adding an anionic surfactant (sodium dodecylsulfate) in a concentration of 50 \mu M, the sensitivity of kinetin was increased significantly without reducing the resolution. The detection limits were 0.14 and 0.11 \mu M (24.53 and 23.67 …
Stable Ester And Amide Conjugates Of Some Nsaids As Analgesic And Antiinflammatory Compounds With Improved Biological Activity, Meci̇t Orhan Uludağ, Burcu Çalişkan Ergün, Duygu Asli Alkan, Ni̇lüfer Ercan, Güler Yağmur Özkan, Erden Banoğlu
Stable Ester And Amide Conjugates Of Some Nsaids As Analgesic And Antiinflammatory Compounds With Improved Biological Activity, Meci̇t Orhan Uludağ, Burcu Çalişkan Ergün, Duygu Asli Alkan, Ni̇lüfer Ercan, Güler Yağmur Özkan, Erden Banoğlu
Turkish Journal of Chemistry
A set of ester and amide derivatives of some acidic NSAIDs, including ibuprofen, ketoprofen, and mefenamic acid (1-3), were synthesized and evaluated for their in vivo analgesic and antiinflammatory activity using the p-benzoquinone-induced writhing test and the carrageenan-induced paw edema model, respectively. Among the synthesized compounds, ester derivatives of ketoprofen showed especially potent analgesic and antiinflammatory activity as compared to the parent drug. In vitro chemical stability studies revealed that ester and amide derivatives were chemically stable in simulated gastric (pH 1.2) and intestinal fluids (pH 6.8). In 80\% human plasma, the ester derivatives were found to be relatively stable …
Simultaneous Determination Of Dopamine, Uric Acid, And Folic Acid By A Modified Tio_2 Nanoparticles Carbon Paste Electrode, Mohammad Mazloum Ardakani, Mohammad Ali Sheikhmohseni, Hadi Beitollahi, Ali Benvidi, Hossein Naeimi
Simultaneous Determination Of Dopamine, Uric Acid, And Folic Acid By A Modified Tio_2 Nanoparticles Carbon Paste Electrode, Mohammad Mazloum Ardakani, Mohammad Ali Sheikhmohseni, Hadi Beitollahi, Ali Benvidi, Hossein Naeimi
Turkish Journal of Chemistry
The electrochemical behavior of dopamine (DA) was studied at the surface of a 2,2-[1,2 buthanediylbis(nit- riloethylidyne)]-bis-hydroquinone/TiO_2 nanoparticles modified carbon paste electrode (BQTMCPE) in aqueous media using voltammetric and chronoamperometric techniques. It was found that under optimum conditions (pH 8.0), the oxidation of DA at the surface of such an electrode occurred at about 220 mV lower than that of an unmodified carbon paste electrode (CPE). Using differential pulse voltammetry (DPV), a highly selective and simultaneous determination of DA, uric acid (UA), and folic acid (FA) was explored at the modified electrode. DPV peak currents of DA, UA, and FA increased …
Bromination Of 2,3-Dihydrobenzobarrelene And Synthesis Of Its Mono- And Dibromide Derivatives: Unexpected Wagner-Meerwein Rearrangement On Silica Gel, Selçuk Eşsi̇z, Mehmet Emi̇n Şengül, Ertan Şahi̇n, Ari̇f Daştan
Bromination Of 2,3-Dihydrobenzobarrelene And Synthesis Of Its Mono- And Dibromide Derivatives: Unexpected Wagner-Meerwein Rearrangement On Silica Gel, Selçuk Eşsi̇z, Mehmet Emi̇n Şengül, Ertan Şahi̇n, Ari̇f Daştan
Turkish Journal of Chemistry
The bromination reaction of dihydrobenzobarrelene under different conditions was studied. The bromination reaction of dihydrobenzobarrelene with molecular bromine gave only a Wagner-Meerwein rearrangement product by aryl and alkyl migration. Its high-temperature bromination reaction resulted in the formation of normal addition products besides rearrangement products. The bromination reaction of the alkene with 1,2- dibromotetrachloroethane (DBTCE) gave a non-rearrangement product as the sole product. The synthesis and bromination reaction of 2-bromodihydrobenzobarrelene was also studied. An unexpected Wagner-Meerwein rearrangement was observed on silica gel during the column chromatography of isomeric tribromides. Herein, we report the results of the synthesis, and the X-ray crystal …
Constituents Of Plantago Major Subsp. Intermedia With Antioxidant And Anticholinesterase Capacities, Ufuk Kolak, Mehmet Boğa, Emi̇ne Akalin Uruşak, Ayhan Ulubelen
Constituents Of Plantago Major Subsp. Intermedia With Antioxidant And Anticholinesterase Capacities, Ufuk Kolak, Mehmet Boğa, Emi̇ne Akalin Uruşak, Ayhan Ulubelen
Turkish Journal of Chemistry
The methanol extract of Plantago major subsp. intermedia (Gilib.) Lange afforded 4 known compounds, namely isomartynoside (1), 10-hydroxymajoroside (2), \beta -sitosterol (3), and ursolic acid (4). Their structures were established by spectroscopic methods. After determination of the total phenolic and flavonoid contents of the methanol extract, the antioxidant potentials of the crude extract and isolated compounds 1-4 were determined by \beta -carotene bleaching, DPPH free radical and ABTS cation radical scavenging, and cupric reducing antioxidant capacity methods. The methanol extract, rich in phenolic contents, indicated the same DPPH free radical scavenging activity (72\% inhibition) as a standard compound, butylated hydroxytoluene, …
Chemistry Of Dibenzobarallene, Moustafa A. Gouda, Moged A. Berghot, Khaled M. Elattar, Abd El Galil M. Khalil
Chemistry Of Dibenzobarallene, Moustafa A. Gouda, Moged A. Berghot, Khaled M. Elattar, Abd El Galil M. Khalil
Turkish Journal of Chemistry
This review represents a systematic and comprehensive survey of the methods of syntheses and chemical reactivity of dibenzobarallene. This compound is an important intermediate for the synthesis of useful and novel heterocycle systems.
Synthesis Of Starch-G-Poly(Acrylic Acid-Co-2-Hydroxy Ethyl Methacrylate) As A Potential Ph-Sensitive Hydrogel-Based Drug Delivery System, Mohammad Sadeghi
Synthesis Of Starch-G-Poly(Acrylic Acid-Co-2-Hydroxy Ethyl Methacrylate) As A Potential Ph-Sensitive Hydrogel-Based Drug Delivery System, Mohammad Sadeghi
Turkish Journal of Chemistry
The present work focused on the design of a drug delivery system (DDS) based on pH-sensitive hydrogel. The hydrogels were prepared via graft copolymerization of mixtures of acrylic acid (AA) and 2-hydroxy ethyl methacrylate (HEMA) onto starch backbones by a free radical polymerization technique. Sodium bicarbonate (NaHCO_3) was added to function as a foaming agent under acidic conditions, rendering the hydrogels to be porous. The porous structure of the hydrogel was essential in this system to yield a large surface area so that 5-fluorouracil (5-FU) release could be facilitated. The hydrogel, thus prepared, possessed a porous structure as determined by …
Electrochemical Impedance Spectroscopy Study On Intercalation And Anomalous Diffusion Of Alcl_4^- Ions Into Graphite In Basic Molten Salt, Ali Ehsani, Mohammad Ghasem Mahjani, Majid Jafarian
Electrochemical Impedance Spectroscopy Study On Intercalation And Anomalous Diffusion Of Alcl_4^- Ions Into Graphite In Basic Molten Salt, Ali Ehsani, Mohammad Ghasem Mahjani, Majid Jafarian
Turkish Journal of Chemistry
Electrochemical impedance spectroscopy (EIS) was employed to investigate diffusion of AlCl_4^- ions in basic (AlCl_3-NaCl-KCl) molten salt. Nyquist plots in different DC offset potentials showed finite and restricted aluminum ion diffusion due to insertion and blocking in the graphite electrode. The general Warburg, open Warburg, and short Warburg impedance in the complex Nyquist plot of this system showed the anomalous diffusion behavior of the ions in the graphite electrode. The diffusion coefficient of the AlCl_4^- ions was calculated from the slope of the Warburg line in a totally blocking film in the graphite electrode and was found to be 2.8 …
Studies On The Mechanism Of Phosphazene Ring-Opening Polymerization (Rop), Selen Bi̇lge
Studies On The Mechanism Of Phosphazene Ring-Opening Polymerization (Rop), Selen Bi̇lge
Turkish Journal of Chemistry
In this study, the ring-opening polymerization (ROP) of cyclic trimer N_3P_3Cl_6 catalyzed by [Et_3Si(N_3 P_3Cl_6)][CHB_{11}H_5Br_6] (3) obtained from the reaction of N_3P_3Cl_6 (1) and Et_3Si(CHB_{11}H_5Br_6) (2) at room temperature was investigated. This provided a unique opportunity to explore the polymerization mechanism. The coordinatively unsaturated cation [N_3P_3Cl_5]^+ is responsible for the ROP of N_3P_3Cl_6, and is formed by the intramolecular elimination of Et_3SiCl from 3. The detection of Et_3SiCl by ^1H-NMR as the catalysis proceeded offers new evidence for the formation of [N_3P_3Cl_5]^+. The progress of the catalysis was followed using ^{31} P-NMR and revealed the build-up of a polymer. Cyclic …
Synthesis And Characterization Of A New Methacrylic Glycomonomer, Liliana Marinela Stefan, Ana Maria Pana, Mihai Cosmin Pascariu, Eugen Sisu, Geza Bandur, Lucian Mircea Rusnac
Synthesis And Characterization Of A New Methacrylic Glycomonomer, Liliana Marinela Stefan, Ana Maria Pana, Mihai Cosmin Pascariu, Eugen Sisu, Geza Bandur, Lucian Mircea Rusnac
Turkish Journal of Chemistry
The carbohydrate containing monomer 3-O-(2'-hydroxy-3'- methacryloyloxypropyl)-1,2:5,6-di-O-isopropylidene-\alpha -D-glucofuranose was easily prepared from D-glucose and methacrylic acid in 4 steps. The structure of the new methacrylic monomer was confirmed using FTIR, NMR (including ^1H-NMR, ^{13}C-NMR, COSY, HMQC and HMBC), and HPLC-MS. This work is part of our group's effort to obtain new polymers based on renewable resources with enhanced biodegradability and biocompatibility.
Polyphenolic Compounds From Geranium Purpureum Vill. Growing In Turkey, Di̇dem Şöhretoğlu, Mahmut Koray Sakar, Olov Sterner
Polyphenolic Compounds From Geranium Purpureum Vill. Growing In Turkey, Di̇dem Şöhretoğlu, Mahmut Koray Sakar, Olov Sterner
Turkish Journal of Chemistry
Two new flavonol derivatives, Geranioside A (kaempferol 3-[3-(\alpha-rhamnopyranosyl)-4-oxy-5-hydroxy-6-methyl-3,4-dihyropyran-2H- 2-pyranoside]) (1) and Geranioside B (quercetin 3-[3-(\alpha-rhamnopyranosyl)- 4-oxy-5-hydroxy-6-methyl-3,4-dihyropyran-2H-2-pyranoside]) (2), along with 5 known flavonols (quercetin (3), kaempferol (4), quercetin 4'-O-\beta -glucopyranoside (5), quercetin 3-O-\beta -glucopyranoside (6), and kaemferol-3-O-\beta -glucopyranoside (7)), a gallic acid derivative (methyl gallate (8)), and a hydrolysable tannin (pusilagin (9)), were isolated from the aerial parts of Geranium purpureum. The structures of the isolated compounds were elucidated on the basis of UV, IR, and 1D- and 2D-NMR experiments as well as TOF-MS.
Power Of Inhibition Activity Screening And 3d Molecular Modeling Approaches In Hdac 8 Inhibitor Design, Gamze Bora Tatar, Tenzi̇le Deni̇z Tokluman, Kemal Yelekçi̇, Hayat Yurter
Power Of Inhibition Activity Screening And 3d Molecular Modeling Approaches In Hdac 8 Inhibitor Design, Gamze Bora Tatar, Tenzi̇le Deni̇z Tokluman, Kemal Yelekçi̇, Hayat Yurter
Turkish Journal of Chemistry
In-vitro inhibition activity screening and in-silico 3D molecular modeling approaches are important tools for design and development of specific histone deacetylase (HDAC) inhibitors. The objective of this study was to investigate the consistency between these 2 approaches. The HDAC 8 inhibition activities of 8 randomly selected different carboxylic acid derivatives were screened and in-vitro experimental results were compared with in-silico molecular modeling calculations. This study demonstrated that there is no sole gold standard technique for inhibitor design, and it was concluded that a combination of molecular modeling and activity screening assays will ensure more comprehensive and dependable results.
Arsenic And Antimony Determination In Refined And Unrefined Table Salts By Means Of Hydride Generation Atomic Absorption Spectrometry--Comparison Of Sample Decomposition And Determination Methods, Nur Aksuner, Vedi̇a Nüket Ti̇rtom, Emür Henden
Arsenic And Antimony Determination In Refined And Unrefined Table Salts By Means Of Hydride Generation Atomic Absorption Spectrometry--Comparison Of Sample Decomposition And Determination Methods, Nur Aksuner, Vedi̇a Nüket Ti̇rtom, Emür Henden
Turkish Journal of Chemistry
An evaluation was made of different digestion methods for the determination of arsenic and antimony in table salt samples prior to hydride generation atomic absorption spectrometric analysis. Microwave acid digestion, classical wet digestion, dry ashing, and fusion were applied to the decomposition of salt samples and optimum conditions were investigated. Samples were decomposed by changing heating time, digestion techniques, and the amount and composition of acid, and then the concentrations of arsenic and antimony in an unrefined salt sample were measured. It is concluded that microwave acid digestion decomposes salt samples with a very short heating time and with small …
Facile And Convenient Synthesis Of Pyrimidine, 4h-3,1-Benzoxazin-4-One, Pyrazolo[5,1-B]Quinazoline, Pyrido[1,2-A]Quinazoline, And Chromeno[3' ,4' :4,5]Pyrido[1,2-A]Quinazoline Derivatives, Yousry A. Ammar, Samir Bondock, Abdallah G. El-Sehmi, Mohamed S.A El_Gaby, Ahmed M. Fouda, Hamdy Kh. Thabet
Facile And Convenient Synthesis Of Pyrimidine, 4h-3,1-Benzoxazin-4-One, Pyrazolo[5,1-B]Quinazoline, Pyrido[1,2-A]Quinazoline, And Chromeno[3' ,4' :4,5]Pyrido[1,2-A]Quinazoline Derivatives, Yousry A. Ammar, Samir Bondock, Abdallah G. El-Sehmi, Mohamed S.A El_Gaby, Ahmed M. Fouda, Hamdy Kh. Thabet
Turkish Journal of Chemistry
A convenient synthesis of a series of pyrimidine, 4H-3,1-benzoxazin-4-one, pyrazolo[5,1-b]quinazoline, pyrido[1,2-a]quinazoline, and chromeno[3' ,4' :4,5]pyrido[1,2-a]quinazoline derivatives, via the reactions of versatile and readily accessible methyl 2-(2-cyanoacetamido)benzoate (1) with the appropriate reagents, is described here.
Enantioselective Complexation Of Chiral Lariat Crown Ethers And Chiral Primary Alkylammonium Perchlorates, Mehmet Zafer Köylü, Tarik Aral, Mehmet Karakaplan, Şafak Özhan Kocakaya, Hali̇l Hoşgören
Enantioselective Complexation Of Chiral Lariat Crown Ethers And Chiral Primary Alkylammonium Perchlorates, Mehmet Zafer Köylü, Tarik Aral, Mehmet Karakaplan, Şafak Özhan Kocakaya, Hali̇l Hoşgören
Turkish Journal of Chemistry
In order to investigate the enantiomeric recognition abilities toward 2 chiral alkylammonium perchlorates (AmI, AmII) by ^1H-NMR titration method in CDCl_3, 4 chiral lariat ethers 8-11 with a (p-methoxyphenoxy) methyl flexible side arm were used. The most effective enantiomeric recognition was obtained by LCEs 9 and 11 toward AmII, by K_R/K_S 6.58 and K_S/K_R 6.63, respectively. The effect of macroring size, subunit of macroring, and side arm appeared to have strong influence on the binding ability of these alkylammonium ions.
Polarographic Determination Of Anticancer Drug Vitamin K_3 With Direct And Indirect Methods/Application To Serum And K_3 Injection Solution, Ümmi̇han Taşkoparan Yilmaz, Güler Somer
Polarographic Determination Of Anticancer Drug Vitamin K_3 With Direct And Indirect Methods/Application To Serum And K_3 Injection Solution, Ümmi̇han Taşkoparan Yilmaz, Güler Somer
Turkish Journal of Chemistry
In this work, direct and indirect methods for determination of vitamin K_3 were developed using differential pulse polarography. The reaction between sulfite and the quinone (Q) form of vitamin K_3 was used for indirect determination, since the sulfite peak at -0.7 V is sharp and very reproducible in 0.1 M HAc NaAc (pH = 5.5). It was found that at pH 4.5-5.5, this reaction was quantitative and very fast when the temperature was 45 °C. For its direct determination, on the other hand, vitamin K_3 was standardized by the indirect method using standard sulfite as the reducing agent. The calibration …
Synthesis And Spectral Characterization Of A Decavanadate/Chitosan Complex, Violeta Dimitrova Kassabova Zhetcheva, Lilyana Parvanova Pavlova
Synthesis And Spectral Characterization Of A Decavanadate/Chitosan Complex, Violeta Dimitrova Kassabova Zhetcheva, Lilyana Parvanova Pavlova
Turkish Journal of Chemistry
A decavanadate/chitosan complex was synthesized by crosslinking chitosan with decavanadate anions at a pH of 3. The materials were characterized by Fourier transformed infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), absorption spectroscopy (UV-Vis), and transmission electron microscopy (TEM). The spectroscopic results indicated that the decavanadate/chitosan complex was successfully obtained as result of an ionic crosslinking of the chitosan with decavanadate anions.
Stability Study Of Passive Film On Copper Surface As A Function Of Anodic Potential, Amtul Naseer, Athar Yaseen Khan
Stability Study Of Passive Film On Copper Surface As A Function Of Anodic Potential, Amtul Naseer, Athar Yaseen Khan
Turkish Journal of Chemistry
Results for passive film formation and breakdown on copper disk electrodes in buffer solutions, pH 9.2 and 8.5, were reported earlier. The present studies were carried out in a buffer solution, pH 8.0, and together these studies make good material for understanding the effect of pH changes on film texture as a function of potential. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to examine passive film and the variations it went through upon being treated potentiostatically in the range of -0.3 to 0.9 V. On the basis of equivalent circuits used for modeling impedance data in this …
Synthesis And Characterization Of Novel Benzovesamicol Analogs, Thaer Assaad
Synthesis And Characterization Of Novel Benzovesamicol Analogs, Thaer Assaad
Turkish Journal of Chemistry
Three new racemic vesamicol analogs were successfully prepared in good yields and high purity. All compounds were characterized by both IR and NMR spectroscopy. Compounds (\pm)-5 and (\pm)-6 showed a moderate lipophilicity compared with reference compounds IBVM and DRC140, respectively. However, the lipophilicity of DRC140 and (\pm)-9 showed very similar behaviors.