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Articles 1531 - 1560 of 2720
Full-Text Articles in Chemistry
Chemical And Biotransformation Of Gelomulide F: A Rare Diterpene Lactone, Humaira Yasmeen Gondal, Muhammad Iqbal Choudhary
Chemical And Biotransformation Of Gelomulide F: A Rare Diterpene Lactone, Humaira Yasmeen Gondal, Muhammad Iqbal Choudhary
Turkish Journal of Chemistry
Chemical and biotransformations of a rare diterpene lactone, Gelomulide F (1), from the cytotoxic extract of leaves of Suregada multiflora were studied. Fermentation of compound 1 with Sachromyces cerevisiae transformed it to Gelomulide D (2) and E (3), whereas its treatment with 2N KOH yielded Gelomulide D (2). In addition, a novel compound (4) was obtained by its diastereo and chemoselective reduction with NaBH_4. All of these compounds were characterized on the basis of extensive ^1H-NMR, ^{13}C-NMR, 2D NMR, and mass spectral analyses.
Bifunctionalized Linked Bis-Spiro[Furo[2,3-D]Pyrimidine-6,5'- Pyrimidine]2,2',4,4',6'(3h,3'H,5h)-Pentaones Derived From One-Pot Reaction Of (Thio)Barbituric Acids With Aromatic Dialdehydes And Brcn In The Presence Of Et_3n, Nader Noroozi Pesyan, Mohammad Jalilzadeh
Bifunctionalized Linked Bis-Spiro[Furo[2,3-D]Pyrimidine-6,5'- Pyrimidine]2,2',4,4',6'(3h,3'H,5h)-Pentaones Derived From One-Pot Reaction Of (Thio)Barbituric Acids With Aromatic Dialdehydes And Brcn In The Presence Of Et_3n, Nader Noroozi Pesyan, Mohammad Jalilzadeh
Turkish Journal of Chemistry
Reaction of pyrimidine-(1H,3H,5H)-2,4,6-trione (barbituric acid), 1,3-dimethyl pyrimidine-(1H,3H,5H)-2,4,6-trione (1,3-dimethyl barbituric acid), and 1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H)- dione (1,3-diethyl thiobarbituric acid) with cyanogen bromide and aromatic dialdehydes in the presence of triethylamine leads to the selective and efficient formation of a novel class of bifunctionalized stable heterocyclic bis-spiro[furo[2,3-d]pyrimidine-6,5'-pyrimidine] 2,2',4,4',6'(3H,3'H,5H)pentaones and their sulfur analogues, which are dimeric forms of barbiturate linked by a phenyl ring. A proposed mechanism was suggested for the formation of the products. The reaction of phthalaldehyde with BrCN and (thio)barbituric acids resulted in only monofunctionalized spiro[furo[2,3-d]pyrimidine-6,5'- pyrimidine]2,2',4,4',6'(3H,3'H,5H)pentaones, while isophthalaldehyde and terphthalaldehyde resulted in the bifunctionalized form.
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.
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 …
Synthesis And Biological Activity Of 5-Substituted-2-Amino-1,3,4-Oxadiazole Derivatives, Sanjeev Kumar
Synthesis And Biological Activity Of 5-Substituted-2-Amino-1,3,4-Oxadiazole Derivatives, Sanjeev Kumar
Turkish Journal of Chemistry
Electrical energy offers numerous benefits for performing synthesis, including increased reaction rates, enhanced yields, and cleaner chemistries. 5-Substituted-2-amino-1,3,4-oxadiazoles were synthesized directly from the semicarbazone at a platinum electrode under controlled potential electrolysis in an undivided cell assembly in acetonitrile. The compounds were screened for antibacterial and antifungal activity against Staphylococcus aureus, Klebsiella pneumoniae, Pellicularia salmonicolor, and Macrophomina phaseolina.
Antimicrobial Activity And Volatile Constituents Of The Flower, Leaf, And Stem Of Paeonia Daurica Grown In Turkey, Gonca Tosun, Nuran Kahri̇man, Canan Albay, Şengül Alpay Karaoğlu, Nuretti̇n Yayli
Antimicrobial Activity And Volatile Constituents Of The Flower, Leaf, And Stem Of Paeonia Daurica Grown In Turkey, Gonca Tosun, Nuran Kahri̇man, Canan Albay, Şengül Alpay Karaoğlu, Nuretti̇n Yayli
Turkish Journal of Chemistry
The volatile constituents of the essential oils from the flower, leaf, and stem of Paeonia daurica Andrews were analyzed by GC and GC-MS. A total of 74 compounds were identified, constituting over 95.0%, 80.8%, and 98.2% of the oil composition of the flower, leaf, and stem of P. daurica, respectively. Aldehydes were shown to be the main group of constituents of the flower and stem parts, at 39.1% and 79.8%, respectively. However, the major group in the leaf oil was found to be oxygenated monoterpenes (43.5%). Salicylaldehyde (20.7% and 79.5%) was the major component of the flower and stem oils …
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 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.
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.
E)--2--Acetyl--4--(4--Methoxyphenyldiazenyl) Phenol: X--Ray And Dft--Calculated Structure, Serap Yazici, Çi̇ğdem Albayrak, İsmai̇l Erdem Gümrükçüoğlu, İsmet Şenel, Orhan Büyükgüngör
E)--2--Acetyl--4--(4--Methoxyphenyldiazenyl) Phenol: X--Ray And Dft--Calculated Structure, Serap Yazici, Çi̇ğdem Albayrak, İsmai̇l Erdem Gümrükçüoğlu, İsmet Şenel, Orhan Büyükgüngör
Turkish Journal of Chemistry
The crystal structure of the title compound, (E)-2-acetyl-4-(4-methoxyphenyldiazenyl) phenol, displays a trans configuration of the azo moiety as found for other azo (diazene) derivatives. The aromatic mean planes are nearly coplanar and the dihedral angle between the 2 aromatic rings is 3.04(8)°. The molecules, with strong intramolecular O--H...O hydrogen bonding, are linked by weak van der Waals interactions in the 3-dimensional network. The molecular geometry, determined using X-ray diffraction techniques, was also calculated with the density functional theory (DFT), employing the hybrid exchange-correlation functional B3LYP. Experimental and theoretical IR spectra of the compound were also calculated for comparison. The results …
Electrocatalytic Oxidation Of Ethanol On Various Metal Ad-Layer Modified Au(111) Electrodes In Alkaline Solution, Zekerya Dursun, Şükri̇ye Ulubay Karabi̇beroğlu, Buket Gelmez, Aydan Başaran
Electrocatalytic Oxidation Of Ethanol On Various Metal Ad-Layer Modified Au(111) Electrodes In Alkaline Solution, Zekerya Dursun, Şükri̇ye Ulubay Karabi̇beroğlu, Buket Gelmez, Aydan Başaran
Turkish Journal of Chemistry
Ethanol oxidation was studied on single-crystal Au(111) electrodes that were modified by platinum, palladium, and cadmium metal ad-layers. The metal ad-layer modification was carried out by the underpotential deposition process, in which controlled amounts of Pt, Pd, and Cd were electrodeposited onto the substrate as submonolayer or monolayer coverage. The activity of the metal ad-layer modified Au(111) electrodes toward ethanol oxidation was studied in alkaline media, and recorded voltammograms were compared to those of bare single crystal Au(111) and polycrystalline gold and platinum disk electrodes. In terms of the desired shift in reduction potential and increased current density, the best …
Tridentate Ligands Derived From L-Tert-Leucine For The Cu(Ii) Mediated Asymmetric Henry Reaction, Nesli̇han Korkmaz, Demet Astley, Stephen Thomas Astley
Tridentate Ligands Derived From L-Tert-Leucine For The Cu(Ii) Mediated Asymmetric Henry Reaction, Nesli̇han Korkmaz, Demet Astley, Stephen Thomas Astley
Turkish Journal of Chemistry
Chiral tridentate Schiff base ligands were prepared from L-tert-Leucine and used as catalysts in the asymmetric Henry reaction in the presence of Cu(II) ions. Moderate enantiomeric excesses (up to 66%) and yields (up to 76%) of the desired \beta-nitroalcohols were obtained.
Zno Nanoflake Arrays Prepared Via Anodization And Their Performance In The Photodegradation Of Methyl Orange, Huey-Shya Goh, Rohana Adnan, Muhammad Akhyar Farrukh
Zno Nanoflake Arrays Prepared Via Anodization And Their Performance In The Photodegradation Of Methyl Orange, Huey-Shya Goh, Rohana Adnan, Muhammad Akhyar Farrukh
Turkish Journal of Chemistry
In the present work, anodization of zinc foil was investigated in a mixed electrolyte of ammonium sulfate and sodium hydroxide under the influence of different anodization times and concentrations of the electrolyte while the temperature and voltage were kept constant. The ZnO nanoflake arrays formed on Zn foil were characterized using a field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX) analysis, and X-ray diffraction (XRD). The size of the nanoflakes increased as the anodization time increased, while increasing the concentration of (NH_4)_2SO_4 increased the dissolution of the nanoflakes. Upon stirring, the nanoflakes that formed were more uniform …
Microwave Synthesis Of Some New Antimicrobial And Antiproliferative Butenamides And Pyrrolidine-2,5-Diones, Shadia Mahmoud Abdallah, Halima Aly Hefny
Microwave Synthesis Of Some New Antimicrobial And Antiproliferative Butenamides And Pyrrolidine-2,5-Diones, Shadia Mahmoud Abdallah, Halima Aly Hefny
Turkish Journal of Chemistry
Microwave irradiation, comparable to conventional thermal heating, proves to be a convenient method in assisting the synthesis of some butenamides, pyrrolidine-2,5-diones, and their benzenesulfonamido derivatives, which are known to have biological activities and wide medical and industrial applications. Both procedures were used to compare their efficiency in synthesizing butenamides and pyrrolidine-2,5-diones (2-25), which have important and wide applications, from condensation of \alpha,\beta-unsaturated anhydride (1) with the corresponding amines. Some of the products showed biological or cytotoxic (antiproliferative) activity.
Qsar And Docking Studies Of Inhibition Activity Of 5,6-Dihydro 11-Alkylbenzo[\Alpha]Carbazole Derivatives Against Estrogen Receptor, Tuğba Taşkin, Fatma Sevi̇n
Qsar And Docking Studies Of Inhibition Activity Of 5,6-Dihydro 11-Alkylbenzo[\Alpha]Carbazole Derivatives Against Estrogen Receptor, Tuğba Taşkin, Fatma Sevi̇n
Turkish Journal of Chemistry
In the present study, QSAR and docking studies were applied to understand the nature of 5,6-dihydro 11-alkylbenzo[\alpha]carbazole derivatives and to investigate the interactions of homolog series with binding sites on selected a-chains of human estrogen receptors (hER). The best QSAR model was selected, having the correlation coefficient r = 0.924, squared correlation coefficient r^2 = 0.854, standard deviation s = 0.357, and cross-validated squared correlation coefficient Q^2 = 0.755. The QSAR model indicated that the descriptors E-HOMO and heat of formation play an important role in human estrogen receptor inhibitor activities. A docking study was also utilized to visualize the …
In Silico Design Of Novel And Highly Selective Lysine-Specific Histone Demethylase Inhibitors, Ebru Demet Akdoğan, Burak Erman, Kemal Yelekçi̇
In Silico Design Of Novel And Highly Selective Lysine-Specific Histone Demethylase Inhibitors, Ebru Demet Akdoğan, Burak Erman, Kemal Yelekçi̇
Turkish Journal of Chemistry
Histone lysine-specific demethylase (LSD1) is involved in a wide range of epigenetic processes and plays important roles in gene silencing, DNA transcription, DNA replication, DNA repair, and heterochromatin formation. Its active site shows a resemblance to those of 2 homologous enzymes, monamine oxidase A and B (MAO-A and MAO-B.) In the present work, starting from suitable scaffolds and generating thousands of structures from them, 10 potential inhibitors were obtained with structural and physicochemical properties selectively suitable for inhibiting LSD1. iLib Diverse software was used to generate the diverse structures and 3 docking tools, CDOCKER, GOLD, and AutoDock, were used to …
Synthesis And Antimicrobial Activities Of Some Bridged Bis-Benzimidazole Derivatives, Hasan Küçükbay, Ülkü Yilmaz, Ni̇hat Şi̇reci̇, Ayşe Ni̇lay Güvenç
Synthesis And Antimicrobial Activities Of Some Bridged Bis-Benzimidazole Derivatives, Hasan Küçükbay, Ülkü Yilmaz, Ni̇hat Şi̇reci̇, Ayşe Ni̇lay Güvenç
Turkish Journal of Chemistry
Some bis-benzimidazoles derivatives bearing allyl, crotyl, cinammyl, furfuryl, and thenyl groups were synthesized and their in vitro antimicrobial activity determined against gram-positive and gram-negative bacteria, and fungi by disk-diffusion method. The structures of all new compounds were identified by ^1H-NMR, ^{13}C-NMR, and FT-IR spectroscopic techniques and elemental analysis. All the compounds synthesized in this work were examined for their in vitro antimicrobial activities against gram-positive (Staphylococcus aureus and Bacillus megaterium) and gram-negative bacteria (Klebsiella pneumoniae and Escherichia coli), and the yeasts like fungi (Candida globrata and Candida tropicalis). Compared to the reference substances, Cefozine and nystatin, most of the compounds …
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 …
Solidified Floating Organic Drop Microextraction And Spectrophotometric Determination Of Vanadium In Water Samples, Shayessteh Dadfarnia, Ali Mohammad Haji Shabani, Akram Mirshamsi
Solidified Floating Organic Drop Microextraction And Spectrophotometric Determination Of Vanadium In Water Samples, Shayessteh Dadfarnia, Ali Mohammad Haji Shabani, Akram Mirshamsi
Turkish Journal of Chemistry
Solidified floating organic drop microextraction (SFODME) was used as a sample preparation method prior to spectrophotometric determination of trace amounts of vanadium in water samples. 8-Hydroxyquinoline (oxine) was used as the chelating agent. The main parameters affecting the performance of SFODME, such as pH, concentration of oxine, extraction time, sample and organic phase volume, extraction temperature, and the nature of the organic solvent, were optimized. Under the optimized conditions, an enhancement factor of 38, detection limit of 0.97 \mu g L^{-1}, and good relative standard deviation of \pm 3.9% at 10 \mu g L^{-1} were obtained. The method was successfully …
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 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.
Preparation And Characterization Of A Series Of Thiourea Derivatives As Phase Change Materials For Thermal Energy Storage, Cemi̇l Alkan, Yusuf Tek, Derya Kahraman
Preparation And Characterization Of A Series Of Thiourea Derivatives As Phase Change Materials For Thermal Energy Storage, Cemi̇l Alkan, Yusuf Tek, Derya Kahraman
Turkish Journal of Chemistry
A series of solid-liquid phase change materials, thiourea derivatives, were prepared via condensation of thiourea with the respective carboxyl chlorides (lauroyl chloride, myristoyl chloride, and palmitoyl chloride) and were then characterized by using FT-IR, ^1H-NMR, differential scanning calorimetry (DSC), and thermogravimetric (TG) analysis. The thiourea derivatives (1,3-didodecanoyl thiourea, 1,3-ditetradecanoyl thiourea, and 1,3-dihexadecanoyl thiourea) were structurally symmetric and had long alkyl groups to crystallize. Thermal analysis by DSC and spectroscopic investigation by FT-IR spectroscopy were performed on the samples before and after thermal cycling tests to determine thermal reliability. The maximum latent heats of melting and freezing of the thiourea derivatives …
Remediation Of Various Naturally Oxygenated Volatile Organic Compounds (O-Vocs) By Mn- And Cr-Supported \Gamma -Al_2o_3 Nanocatalysts, Dariush Salari, Aligholi Niaei, Seyed Ali Hosseini, Reza Leshzadeh, Hosein Afshary
Remediation Of Various Naturally Oxygenated Volatile Organic Compounds (O-Vocs) By Mn- And Cr-Supported \Gamma -Al_2o_3 Nanocatalysts, Dariush Salari, Aligholi Niaei, Seyed Ali Hosseini, Reza Leshzadeh, Hosein Afshary
Turkish Journal of Chemistry
The catalytic combustions of different naturally oxygenated volatile organic compounds (ethyl acetate, isopropanol, methyl ethyl ketone (MEK), and benzyl alcohol) alone and in binary mixtures were investigated over pure \gamma -Al_2O_3, Mn/\gamma -Al_2O_3, and Cr/\gamma -Al_2O_3. The catalysts were prepared by the wet impregnation method and were characterized using XRD, ICP-AES, SEM, and BET. Mn/\gamma -Al_2O_3 showed higher activity than others in combustion of the O-VOCs, whereas complete conversion of isopropanol (the most reactive O-VOC) occurred at 350 °C and 400 °C on Mn/\gamma -Al_2O_3 and Cr/\gamma -Al_2O_3, respectively. The following order was found for reactivity of organic compounds in …
Simultaneous Determination Of Trace Sn(Ii) And Sn(Iv) Using Differential Pulse Polarography And Application, Güler Somer, Ülkü Ünal
Simultaneous Determination Of Trace Sn(Ii) And Sn(Iv) Using Differential Pulse Polarography And Application, Güler Somer, Ülkü Ünal
Turkish Journal of Chemistry
A new method was established for the simultaneous determination of Sn(II) and Sn(IV) using differential pulse polarography (DPP). Among several electrolytes, 0.1 M NaOH in the presence of 0.1 M KNO_3 was found to be the most suitable one. In this medium, Sn(II) had 2 peaks, at -0.74 and -1.17 V, which were sharp and very sensitive. Sn(IV), on the other hand, had a very small peak at -0.92 V when its concentration was higher than 4.0 \times 10^{-4} M. Thus, it was decided to determine Sn(IV) after reduction into Sn(II). In the presence of both Sn(II) and Sn(IV), Sn(II) …
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 …
Synthesis And Characterisation Of Tris(2,4-Dinitrophenoxo)Monooxovanadium(V) And Its Complex Salts, Neeraj Sharma, Reena Sharma, Meena Kumari, Subhash Chaudhry
Synthesis And Characterisation Of Tris(2,4-Dinitrophenoxo)Monooxovanadium(V) And Its Complex Salts, Neeraj Sharma, Reena Sharma, Meena Kumari, Subhash Chaudhry
Turkish Journal of Chemistry
The monooxovanadium(V) complex of composition [VO(OC_6H_3(NO_2)_2-2,4)_3] (I) was synthesized by the reaction of VOCl_3 with Me_3SiOC_6H_3(NO_2)_2-2,4 in toluene and characterised by elemental analyses, molar conductance, and IR, ^1H- and ^{13}C-NMR, and mass spectral studies. The reactions of (I) with alkali metal 2,4-dinitrophenoxides [MOC_6H_3(NO_2)_2-2,4] (M = Li, Na, K) yield complex salts of composition M[VO(OC_6H_3(NO_2)_2-2,4]_4 authenticated by physicochemical and IR spectral studies. Thermal behaviour of complexes was studied by TG and DTA techniques. The molecular modelling calculations of the parent complex and its complex salts were performed to visualise the probable geometry around vanadium metal, which, coupled with spectroscopic evidence, suggests …