Chemistry Commons^™

Modeling And Optimizing Microwave-Assisted Extraction Of Antioxidant Compounds From Marigold Calendula Officinalis L. Using Response Surface Methodology, Burcu Bekdeşer

Turkish Journal of Chemistry

Calendula officinalis L. is a commercially important plant that finds application in the treatment of various diseases in traditional medicine. The total antioxidant capacity, radical scavenging activity, and total phenolic content of marigold extracts were investigated by Folin, CUPRAC, and DPPH assays, respectively. The optimum operating conditions of microwave-assisted extraction (MAE) including temperature, extraction time, solvent-to-solid ratio, and solvent concentration were ascertained by employing response surface methodology (RSM). The solvent (ethanol) concentration was the most significant operating factor among all responses of MAE. At the optimum extraction conditions, the maximum yield of total phenolic content, total antioxidant capacity, and radical …

Investigation Of The Effects Of Some Water-Soluble Vitamins On Glutathione Reductase Enzyme Purified From Bovine Liver, Mehmet Riza Kivanç, Vedat Türkoğlu

Turkish Journal of Chemistry

Glutathione reductase (GR, EC 1.8.1.7) is an antioxidant enzyme and is involved in the reducing reaction of oxidized glutathione. Glutathione and reduced glutathione are very crucial for micro- and macroorganisms because of their barrier function against radicals. Therefore, the aim of this article was to purify GR and evaluate the relationship between purified GR and vitamins. GR was purified from bovine liver using 2',5'-ADP Sepharose 4B column materials. To check the purity of each subunit of the enzyme, SDS-PAGE electrophoresis was performed and each one was 55 kDa. Afterwards, specific activity and purified ratio for the enzyme were calculated as …

One-Pot Synthesis Of Quinazolin-4(3$H$)-Ones And 2,3-Dihydroquinazolin-4(1$H$)-Ones Utilizing $N$-(2-Aminobenzoyl)Benzotriazoles, İlbi̇lge Merve Şenol, İlhami̇ Çeli̇k, İlker Avan

Turkish Journal of Chemistry

A convenient and efficient method has emerged for the one-pot synthesis of substituted quinazolin-4(3$H)$-ones and nonaromatic alkaloids. 2-Substituted quinazolin-4(3H)-ones, 2,3-disubstituted quinazolin-4(3$H)$-ones, and 2,3-dihydroquinazolin-4(1$H)$-ones were obtained at yields of 46% to 95% by a one-pot reaction of $N$-(2-aminobenzoyl) benzotriazoles with amines and orthoesters or aldehydes under catalyst-free conditions.

Evaluation Of The Enrichment And Amplification Effect Of Pentachlorobenzene With Lower Bioconcentration In The Food Chain Before And After Modification, Ruihao Sun, Meijin Du, Yu Li

Turkish Journal of Chemistry

In this paper, in order to construct a 3D quantitative structure--activity relationship (QSAR) model with the chlorobenzene (CB) molecular structure parameter as an independent variable and the octanol-water partition coefficient ($K_{OW})$ as a dependent variable, 9 kinds of CB molecules were used as training sets and 3 kinds of CB molecules were used as test sets. We adopted the QSAR module in the Sybyl-X2.0 software from the Tripos Corporation (USA). The molecular modification of the pentachlorobenzene molecule with low bioconcentration was carried out by combining a three-dimensional contour map and fractional factorial design. The results showed that the toxicity, migration, …

The Solvatochromism And Electronic Structure Of (E)-2-(2-Hydroxystyryl)Quinolin-8-Ol, Ayşegül Gümüş, Yadi̇gar Gülseven Sidir, İsa Sidir, Selçuk Gümüş

Turkish Journal of Chemistry

The (E)-2-(2-hydroxystyryl)quinolin-8-ol (abbreviated as HSQ) molecule was synthesized and characterized. The ESIPT, solvatochromism properties, electronic structure, and ground and excited electric dipole moments of this molecule were measured using absorption and fluorescence spectra recorded in 13 different solvents. Its electronic structure via electronic transitions was investigated to find the quantitative values of solvatochromism properties by LSER calculations. The ESIPT mechanism was clarified; ground and excited dipole moments were determined using solvatochromic shift methods. The DFT (B3LYP)/6-311$++$G(d,p) method and basis set with potential energy surface (PES) calculations of proton transfer were used to explain the ESIPT mechanism. NBO analysis, NLO properties, …

Design, Synthesis, And Antitumor Evaluation Of Novel Methylene Moiety-Tethered Tetrahydroquinoline Derivatives, Esaam Hamied Ahmed Hanashalshahaby, Canan Ünaleroğlu, Ayşe Ak Can, Alp Özgün, Bora Gari̇pcan

Turkish Journal of Chemistry

Novel methylene-tethered tetrahydroquinolines (THQs) and cyclopenta[$b$]pyridines were synthesized by one-pot multicomponent reactions of Mannich bases, enolizable ketones, and NH$_{4}$OAc in water by an environmentally friendly K-10 montmorillonite clay-catalyzed reaction. The cytotoxic activities of 1-(2-methyl-8-methylene-5,6,7,8-tetrahydroquinolin-3-yl)ethanone (9a), ethyl 2-methyl-8-methylene-5,6,7,8-tetrahydroquinoline-3 carboxylate (9b), and 1-(2-methyl-7-methylene-6,7-dihydro-5$H$-cyclopenta[$b$]pyridin-3-yl)ethanone (11a) were tested against rat glioblastoma (C6), human breast cancer (MCF-7), prostate cancer (PC3), neuroblastoma (SH-SY5Y), and mouse fibroblast (L929) cell lines in a concentration-dependent (50-300 μM) and time-dependent (24-72 h) manner and expressed as IC$_{50\, }$values. The results showed that compound 9a induced the lowest IC$_{50\, }$values in all cell lines ranging from 111 ± 1.1 μM to …

Synthesis And Catalytic Activity Of Ionic Palladium \Textit{N}-Heterocyclic Carbene Complexes, Sedat Yaşar, Mi̇tat Akkoç, Namik Özdemi̇r, İsmai̇l Özdemi̇r

Turkish Journal of Chemistry

The synthesis of 3 benzimidazole-based ionic Pd(II)-NHC complexes (NHC:$N$-heterocyclic carbene) is presented. The structures of the complexes are as follows: [NHC-PdBr$_{3}$]$^{-}$[NHC]$^{+}$. The ionic palladium(II)-NHC complexes were synthesized in high yields and were fully characterized by nuclear magnetic resonance spectroscopy, X-ray diffraction, LC-MS/MS, and elemental analysis. These complexes have been identified as active catalysts in Suzuki-Miyaura reactions in a solution of 2-propanol and water at room temperature for different aryl bromides.

Step-By-Step Optimization Of The Hilic Method For Simultaneous Determination Of Abacavir, Lamivudine, And Zidovudine From Dosage Form, Cem Erkmen, Mehmet Gümüştaş, Si̇bel Ayşil Özkan, Bengi̇ Uslu

Turkish Journal of Chemistry

Combined therapy for HIV treatment shows superior efficacy in comparison to single therapy. Furthermore, the separation and determination of the combined dosage forms hold a significant place in the pharmaceutical industry. Not only reverse phase high-performance liquid chromatography (HPLC) but also hydrophilic interaction liquid chromatography (HILIC) can be used for these purposes. Contrary to conventional RP systems, HILIC may be an alternative for the analysis of polar substances. The aim of this study was the step-by-step development of a simple, rapid, and reliable method for the simultaneous determination of antiviral compounds from their marketed formulation (Trizivir). In order to achieve …

Synthesis, Characterization, And Investigation Of Singlet Oxygen, Dna Interaction, And Topoisomerase I Inhibition Properties Of Novel Zinc(Ii) Phthalocyanine, Ümi̇t Demi̇rbaş

Turkish Journal of Chemistry

In this work, phthalonitrile (3) and zinc(II) phthalocyanine (4) were prepared. To determine the photodynamic therapy potential of compound 4, singlet oxygen quantum yield, DNA binding and cleavage, and topoisomerase I inhibition experiments were performed. The singlet oxygen quantum yield value of compound 4 was found higher than that of the standard unsubstituted zinc(II) phthalocyanine compound (Std-ZnPc). The binding experiments showed that compound 4 interacted with ct-DNA strongly via nonintercalation mode. pBR322 plasmid DNA cleavage activity of the compound was investigated using agarose gel electrophoresis. The results showed that the compound 4 had important DNA cleavage activity. The E. coli …

Aqueous Two-Phase Extraction Technique Based On Magnetic Ionic Liquid-Nonionic Surfactant For Phenolic Acids In Grape, Apple, Pear, And Banana, Taşkin Mumcu, Serap Seyhan Bozkurt

Turkish Journal of Chemistry

An aqueous two-phase extraction system was constituted using magnetic ionic liquid-nonionic surfactant for phenolic acids and the developed method was applied to apple, grape, pear, and banana samples. Ionic liquids based on imidazolium containing butyl, allyl, and benzyl groups were used for extraction. The parameters influencing the extraction efficiency such as volume of ionic liquids, type and amount of surfactant and salt, ultrasound extraction time, temperature, and sample pH were optimized. The extraction efficiencies of ionic liquids were compared for phenolic acids under optimized conditions. Limits of detection and limits of quantification were in the range of 1.34-1.56 μg L$^{-1\, …

Synthesis Of Hofmann-Type Zn(H$_2$O)$_2$Ni(Cn)$_4$.Ng (G = Water And 1,4-Dioxane) Clathrates And The Determination Of Their Structural Properties By Various Spectroscopic Methods, Zeki̇ Kartal, Onur Şahi̇n, Abdülkeri̇m Yavuz

Turkish Journal of Chemistry

Two new 2-dimensional cyanide-bridged coordination polymers [Zn(H$_{2}$O)$_{2}$Ni(CN)$_{4}$ 6(H$_{2}$O) and Zn(H$_{2}$O)$_{2}$ Ni(CN)$_{4}$ 3(C$_{4}$H$_{8}$O$_{2})$], which were similar to Hofmann-type clathrates, were synthesized based on [Ni(CN)$_{4}$]$^{2-}$ and Zn$^{2+}$ as building blocks. These substances were synthesized as compounds in crystalline form. Thes tructures of the crystalline compounds were characterized via their spectral analyses. General information about the structures of the newly obtained Hofmann-type clathrates was obtained from their vibration spectra by considering significant changes in the vibration peaks of the cyanide group, water ligand molecule, and guest molecules (water and 1,4-dioxane). The thermal behavior of the Hofmann-type clathrates was investigated in the range of …

Dispersive Liquid-Liquid Microextraction Of Parabens From Pharmaceuticals And Personal Care Products Prior To Their Determination Using Hplc-Dad, Malek Hassan, Usama Alshana, Nusret Ertaş

Turkish Journal of Chemistry

Dispersive liquid--liquid microextraction followed by a back-extraction step was combined with HPLC-DAD for the determination of four parabens (i.e. methyl-, ethyl-, propyl-, and butylparaben). Optimum extraction conditions were found as follows: 225 $\mu $L of chloroform, 0.75 mL of ethanol, 7.5 mL of aqueous solution and within an extraction time of 15 s. Back-extraction into 100 $\mu $L of 50 mM sodium hydroxide solution within 20 s resulted in a reversed-phase HPLC-compatible extract. The analytes were separated at 20 $^{\circ}$C using methanol (A) and water (B), 40:60 (A:B, v/v) as the mobile phase, a flow rate of 1.0 mL min$^{-1}$ …

Surface Modification Of Polyvinyl Chloride By Polyacrylic Acid Graftas A Polyelectrolyte Membrane Using Ar Plasma, Alaa Fahmy, Mouhamed Abu-Saied, Nasser Morgan, Walid Qutop, Hassan Abdelbary, Tarek Salama

Turkish Journal of Chemistry

This work reports the synthesis and properties of a new membrane based on polyvinyl chloride (PVC) grafting with polyacrylic acid (PAA) using argon (Ar) plasma. The membranes of PVC were synthesized by solution-casting method, where PAA was deposited as an ultrathin film onto PVC using dielectric barrier discharge at atmospheric pressure with Ar gas. The surface characteristics and chemical composition of the modified membranes were analyzed by water contact angle, scanning electron microscopy, and Fourier transform infrared spectroscopy. Moreover, the electrochemical properties of the membrane were investigated via ion exchange capacity for the purpose of using it as a polyelectrolyte …

An Ultrasensitive Electrochemical Immunosensor Platform Based On Disposable Ito Electrode Modified By 3-Cptms For Early Detection Of Parathyroid Hormone, İnci̇ Uludağ, Mustafa Kemal Sezgi̇ntürk

Turkish Journal of Chemistry

Parathyroid hormone (PTH) is a polypeptide containing 84 amino acids secreted by cells of the parathyroid glands. Imbalances of parathyroid levels cause medical problems such as osteoporosis, mental disorders, pancreatitis, kidney stones, cancer, and other symptoms. In this study, we aimed to design an ultrasensitive electrochemical immunosensor for PTH detection. Indium tin oxide (ITO) was used as an electrode for electrochemical impedance spectroscopy (EIS) measurements. ITO sheets were modified by using 3-cyanopropyltrimethoxysilane (3-CPTMS) self-assembled monolayers (SAMs) for immobilizing the anti-PTH antibody via covalent interactions. Cyclic voltammetry (CV) and EIS methods were applied to characterize immobilization steps. Therefore, 1% was selected …

Synthesis And Characterization Of Unsaturated Diacyl And Alkyl-Acyl Piperazine Derivatives, Sai̇t Sari, Seda Ünalan, Mehmet Yilmaz

Turkish Journal of Chemistry

The aim of this study is to obtain new unsaturated piperazine compounds by the reactions of piperazine (1a) and piperazine derivatives (1b-1d) with acylation reactive groups (a-2j). Methacryloyl piperazine (1b) was synthesized from the reaction of methacrylic anhydride with piperazine (1a). Acyl chlorides (2b-2d) were prepared from the reaction of thionyl chloride with carboxylic acids (3a-3c) obtained as a result of the reaction with malonic acid and suitable aldehyde (5-methylfuran-2-carbaldehyde for 3a, cinnamaldehyde for 3b, and thiophene-2-carbaldehyde for 3c), respectively, by literature methods. Acyl chlorides 2ed and 2f }were obtained from the reaction of commercially purchased carboxylic acids 3d and …

The Role Of Diazacrown Ether In The Enhancement Of The Biological Activity Of Silver Nanoparticles, Sarvinaz Hajiyeva, Ulviyya Hasanova, Zarema Gakhramanova, Aygun Israyilova, Khudaverdi Ganbarov, Eldar Gasimov, Fuad Rzayev, Goncha Eyvazova, Alakbar Huseynzada, Gunel Aliyeva, Ilaha Hasanova, Abel Maharramov

Turkish Journal of Chemistry

The nanostructuring of hydroxyl-substituted diazacrown-ether (DC) by silver nanoparticles was obtained by green synthesis method in order to increase the antibacterial activity of silver nanoparticles. The synthesized DC, nanoparticles, and nanosupramolecular complex (Ag@DC) were studied by TEM, powder-XRD, and NMR, IR, and UV spectroscopy methods. The Ag@DC nanostructures were uniform and their sizes ranged from 8 to 18 nm. IR and UV spectra revealed the noncovalent formation of the nanosupramolecular complex. The antibacterial activities of the prepared active agents were investigated on gram-positive and gram-negative bacteria by twofold microdilution method. Ultrastructural study by TEM was performed on \textit{E. coli} BDU12 …

Mass Spectrometry Analysis Of Contaminants Of Emerging Concern: Nanoparticles, Algal Toxins, And Cyanotoxins In Natural Waters And Their Potential Health Impacts, Ariel R. Donovan

Doctoral Dissertations

“The analysis of contaminants of emerging concern is critical to protecting environmental health. In the presented dissertation, two groups of contaminants of emerging concern were assessed using mass spectrometry methods: nanoparticles and algal and cyanotoxins.

Analysis of metal oxide nanoparticles in environmental matrices has been a challenging issue, as most traditional methods require complicated sample preparation methods or that can alter or destroy the nanoparticles in the system. Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) methods were used to detect metal oxide nanoparticles in surface waters and their removal through drinking water treatment simulations while retaining all information regarding …

Conformational Communication Mediates The Reset Step In T6a Biosynthesis, Amit Luthra, Naduni Paranagama, William Swinehart, Susan Bayooz, Phuc Phan, Vanessa Quach, Jamie M. Schiffer, Boguslaw Stec, Dirk Iwata-Reuyl, Manal A. Swairjo

Chemistry Faculty Publications and Presentations

The universally conserved N 6-threonylcarbamoylade nosine (t 6 A) modification of tRNA is essential for translational fidelity. In bacteria, t 6 A biosynthesis starts with the TsaC/TsaC2-catalyzed synthesis of the intermediate threonylcarbamoyl adenylate (TC-AMP), followed by transfer of the threonylcarbamoyl (TC) moiety to adenine-37 of tRNA by the TC-transfer complex comprised of TsaB, TsaD and TsaE sub-units and possessing an ATPase activity required for multi-turnover of the t 6 A cycle. We report a 2.5-˚ A crystal structure of the T. maritima TC-transfer complex (TmTsaB 2 D 2 E 2) bound to Mg 2+-ATP in the AT-Pase site, and substrate …

Catalytic Hydrogenation Of Furfural And Furfuryl Alcohol To Fuel Additives And Value-Added Chemicals, Obaid Aldosari, Hamed Alshammari, Mosaed Alhumaimess, Ibrahim Wawata

Turkish Journal of Chemistry

The selective hydrogenation of furfural and furfuryl alcohol at different temperatures has been studied using several catalysts. The effect of various reaction conditions (pressure, catalyst amount, and solvent) was studied. We have shown that Pd/TiO$_{2}$ catalysts can be very effective for the synthesis of 2-methylfuran at room temperature. Using octane as a solvent, the solvent effectiveness was investigated and showed actively high selectivity towards 2-methylfuran and furfuryl alcohol, but there were many byproducts that were still noticed. Although adding Ru to the Pd/TiO$_{2}$ catalyst contributed to reducing the catalytic activity, this addition improved the selectivity to 2-methylfuran and furfuryl alcohol …

Preparation And Physicochemical Characterization Of Zinc Oxide/Sodium Cellulose Composite For Food Packaging, Sherif Mohamed Abdel Salam Keshk, Mohamed Saad Hamdy

Turkish Journal of Chemistry

Zinc oxide/sodium cellulose composite with different ZnO loadings was prepared for the first time. The crystal structures of cellulose, sodium cellulose, and ZnO/sodium cellulose composite were characterized by FT-IR, XRD, XPS, SEM, and EDX. ZnO/sodium cellulose showed a similar XRD pattern to that of cellulose II. The XPS spectrum emphasized the presence of Zn$^{2+}$ and Na$^{+\, }$ ions in the prepared composite. Additionally, the SEM analysis showed the growth of ZnO crystals on the sodium cellulose surface. UV-Vis spectrometry of the ZnO/sodium cellulose spectrum showed a distinguished absorption band at 360 nm that was attributed to the presence of ZnO …

An Insight Into The Therapeutic Potential Of Piperazine-Based Anticancer Agents, Kamran Walayat, Noor Ul Amin Mohsin, Sana Aslam, Matloob Ahmad

Turkish Journal of Chemistry

The piperazine ring system is among the medicinally important nitrogen-containing heterocyclic ring systems and is exploited for the synthesis of various drug molecules. A number of FDA-approved anticancer drugs contain piperazine rings and thus it is considered as an attractive scaffold having extraordinary potential for the development of new anticancer agents. In recent decades there has been an alarming increase in the number of people suffering from cancerous diseases all over the world, which resulted in an extraordinary increase in research reports on new anticancer drug candidates. The aim of this article is to highlight the structural parameters imparting anticancer …

Efficient Synthesis And Antifungal Investigation Of Nucleosides' Quaternary Ammonium Salt Derivatives, Barbara Dmochowska, Lucyna Pellowska-Januszek, Justyna Samaszko-Fiertek, Rafal Slusarz, Roland Wakiec, Janusz Madaj

Turkish Journal of Chemistry

Quaternary ammonium salts are a group of compounds with diverse biological properties, the most important of which are their antiviral, antibacterial, and antifungal activities. The quaternization reactions of 5'-$O$-tosyl derivatives of uridine and thymidine with triethylamine, trimethylamine, 4-($N$,$N$-dimethylamino)pyridine, 2-methylpyridine, and pyridine are described in this article. Two of the synthesized compounds are exceptional because they are first of this type that demonstrate concentration-dependent antifungal in vitro activity against two species of the genus Candida in minimal YNB-SG medium. The experimental results have been extended by adding full atom molecular dynamics simulations and substrates and products energies evaluation.

Plasma O$_{2}$ Modifies The Structure Of Synthetic Zeolite-A To Improve The Removal Of Cadmium Ions From Aqueous Solutions, Alaa Fahmy, Ahmed Elzaref, Hanan Youssef, Hassan Shehata, Magdy Wassel, Jörg Friedrich, Fabienne Poncin-Epaillard, Dominique Debarnot

Turkish Journal of Chemistry

The present study addresses the removal of cadmium ions (Cd(II)) from aqueous solutions at a pH of 7.5 using zeolite-A activated by exposure to oxygen plasma. The activation process was performed over a wide range of plasma powers (10, 20, 30, and 40 W) and exposure times (30 to 360 s). Oxygen plasma cannot chemically modify zeolite to a considerable extent, but it can clean the surface, open blocked pores, and induce the formation of additional OH groups via exposure to humidity in ambient air. Therefore, Cd$^{+2}$ ion removal is increased by approximately 10% with the plasma treatments. Infrared-attenuated total …

Effect Of Polyvinyl Alcohol/Chitosan Blend Ratios On Morphological, Optical, And Thermal Properties Of Electrospun Nanofibers, Gökhan Açik, Musa Kamaci, Burak Özata, Cahi̇de Eli̇f Özen Cansoy

Turkish Journal of Chemistry

In this study, the electrospinning method was used to prepare polyvinyl alcohol (PVA)/chitosan (CS) blend nanofibers from their solutions. The effect of blend ratios (PVA/CS: 1%, 3%, 5%, and 7% (w/w)), applied voltage, and flow rate on the morphological, optical, and thermal properties of electrospun nanofibers were investigated by scanning electron microscopy (SEM), fluorescence and UV-Vis spectroscopies, and thermogravimetric analysis (TGA), respectively. Fourier transform infrared spectroscopy analysis indicated the existence of related functional groups of both PVA and CS in the electrospun fibers. During the electrospinning process, the maximum possible ratio of CS was 7% (w/w). SEM images indicated that …

An Evaluation Of The Adsorption Dynamics Of Phosphate Ions Onto Fe(Ii)-Montmorillonites, Dawei Qin, Shuhua Chang, Min Qiao, Xiaotong Yuan, Wei Liu, Gang Liu

Turkish Journal of Chemistry

Fe(II)-montmorillonites (Fe(II)-MMTs) were prepared by mixing solutions of Fe(II) and montmorillonite at pH 3.5. Two different Fe(II)-MMTs were prepared and the ferrous iron contents were 40 mg/L and 80 mg/L. All samples were characterized by XRD, FT-IR, TGA, DSC, and nitrogen adsorption. By nitrogen adsorption, the pore size can be obtained in the pore diameter curve with average pore widths of 6.67 nm, 9.96 nm, and 17.07 nm, respectively. The removal rate of phosphate increased rapidly during the first 40 min, in which Fe(II)-MMT (1) and Fe(II)-MMT (2) were stronger adsorption systems than MMT. The maximum adsorption was 48.38 mg/g …

Comparative Study Of Solvent Extraction Of Molybdenum By Various Extractants, Abdoul Rachid Chaibou Yacouba, Salmana Laouali Ibrahim, Ibrahim Natatou

Turkish Journal of Chemistry

Solvent extraction of molybdenum from various acid media by Alamine 336, Aliquat 336, TOPO, and DEHPA in kerosene was studied. The extraction efficiency of molybdenum by diisobutyl ketone (DIBK), the effects of various parameters like diluents, mineral acids, extractant concentration, and applications of these extractants on molybdenum extraction contained in the uranium-bearing ore solutions were investigated. DIBK used as solvent can indeed extract the molybdenum without adding any extractants in the range of 20-50 mg/L. Molybdenum was extracted by Aliquat 336 in all mineral acids at more than 90%. On the basis of slope analysis, the compositions of the extracted …

Synthesis, Characterization, And Kinetic Studies Of Multifunctionalized Mesoporous Silica For Adsorption Of Zinc, Ali̇me Çitak

Turkish Journal of Chemistry

The aim of this study is to evaluate the utilization of bifunctional mesoporous silica with a platinum and propylsulfonic acid group (Pt/SBA15-PrSO$_{3}$H) as an adsorbent for the removal of Zn(II) ions from aqueous solutions. The SBA15-functionalized organosulfonic acid material was synthesized with a one-step cocondensation synthesis route. The second step was Pt loading during reduction and deposition into the aqueous suspension of the bifunctional mesoporous silica synthesized by an aqueous solution of formaldehyde as the reducing agent. The propylsulfonic acid and platinum functionalized mesoporous silica were characterized by BET, thermogravimetric analysis, and X-ray diffraction methods. The adsorption properties and thermodynamic …

Synthesis Of Highly Active Crystalline Carbon Nitride Prepared In Various Salt Melts For Photocatalytic Degradation Of Phenol, Mohd Hayrie Mohd Hatta, Hendrik Oktendy Lintang, Siew Ling Lee, Leny Yuliati

Turkish Journal of Chemistry

Crystallinity could have a decisive influence on photocatalytic performance. In this study, the synthesis of crystalline carbon nitride (CN) was studied via an ionic melt polycondensation of urea precursor in the presence of various salt melts, which were KCl-LiCl, KCl-NaCl, and KCl-ZnCl$_{2}$. While all the salt melts helped to improve the optical properties of the CN, only KCl-LiCl salt melt could form crystalline CN as evidenced by its X-ray diffraction pattern. Furthermore, the specific surface area of CN (72 m$^{2}$/g) was maintained when using KCl-LiCl (73 m$^{2}$/g), but it was decreased in the presence of KCl-NaCl (22 m$^{2}$/g) or KCl-ZnCl$_{2}$ …

Naphthoxazoles And Heterobenzoxazoles: Cholinesterase Inhibition And Antioxidant Activity, Ivana Sagud, Irena Skoric, Franko Burcul

Turkish Journal of Chemistry

Finding novel cholinesterase inhibitors that would be able to cross the blood--brain barrier, have favorable pharmacokinetic parameters, and reduce hepatotoxicity along with other side effects has been the main focus of investigations dealing with Alzheimer disease. In this study we evaluated cholinesterase inhibitory and antioxidant activity of seven oxazole derivatives. These compounds have been efficiently and sustainably prepared by photochemical electrocyclization reaction. Various naphthoxazoles have been previously investigated as potential antibacterial, antituberculosis, and anticancer agents. They have also been tested for antioxidant activity, but never for cholinesterase inhibitory activity. Among the tested oxazole derivatives, fused heterobenzoxazole compounds with pyridine and …

1,2-Dibromotetrachloroethane: An Efficient Reagent For Many Transformations By Modified Appel Reaction, Selçuk Eşsi̇z, Ari̇f Daştan

Turkish Journal of Chemistry

An efficient and facile method has been developed for the synthesis of alkyl bromides from various alcohols under mild conditions using a triphenylphosphine (PPh$_{3})$/1,2-dibromotetrachloroethane (DBTCE) complex in excellent yields and very short time (5 min). This method can also be applied for the transformation of chiral alcohols to their corresponding bromides in very high enantiomeric excess. The PPh$_{3}$/DBTCE complex is also successfully applied to ring-opening reactions of cyclic ethers in mild conditions. Esterification, amidation, and formation of acid anhydrides under very mild experimental conditions are also successfully accomplished by following a modification of the Appel reaction protocol in this work.