An Efficient Catalyst for Aldol Condensation Reactions | Author : Yusuf HASSAN, Rosa KLEIN, Prof.Dr. Perry T KAYE | Abstract | Full Text | Abstract :A New manganese complex was synthesised around S,S-1,2-diaminocyclohexane linked ketopinic acid scaffold, and successfully utilised as catalyst in the aldol condensation reactions of benzaldehyde with various aliphatic ketones to obtain products with excellent yield of >99%. |
| EASY SYNTHESIS OF 3,4-DIHYDROPYRIMIDIN -2-(1H)-ONES USING PHOSPHATE FERTILIZERS MAP, DAP AND TSP AS EFFICIENT CATALYSTS | Author : Sarra SIBOUS, Said BOUKHRIS, Rachida GHAILANE, Nouzha HABBADI, Amina HASSIKOU, Abdelaziz SOUIZI | Abstract | Full Text | Abstract :A simple, efficient and green procedure has been developed for the synthesis of dihydropyrimidinones (Products of Biginelli) using phosphate fertilizers (mono-ammonium phosphate (MAP), di-ammonium phosphate (DAP) and triple super phosphate (TSP)) as catalyst. The one-step reaction involved the three compounds, which are registered aromatic aldehydes, dicarbonyl compounds and the urea/thiourea. This new method provides some advantages such as obtaining excellent yields (98%), as well as the short duration of the reaction, which may attain 2 min. These catalytic heterogeneous systems present also the advantage of being easily recycled. |
| BORON AND MOLYBDENUM CONTENTS OF VERBASCUM OLYMPICUM BOISS. GROWING AROUND AN ABANDONED TUNGSTEN MINE: A CASE STUDY FOR ECOLOGICAL PROBLEM SOLVING | Author : Ümran SEVEN ERDEMIR | Abstract | Full Text | Abstract :This study evaluates the competitive or complementary effects of Cd, Cu, Fe, Mn, Mo, Pb, Zn, and W to B levels of Verbascum olympicum Boiss. (Scrophulariaceae) that is one of the main endemic species spread in disturbed areas of abandoned Etibank tungsten mine work at Uludag Mountain (Bursa, Turkey). Samples were harvested from the unpolluted and polluted areas of mine work. Inductively coupled plasma-mass spectrometry was used to determine the levels of selected elements from leaves and soils of V. olympicum. Classical open wet and Kjeldahl digestions were applied to the samples. Accuracy was evaluated using two kinds of certified reference materials. Complementary behaviors of B and Mo were found in leaves of this species rather than its soils that may help to adaptation properties of this species on the destroyed area. |
| Synthesis of Novel Diarylethenes Bearing Naphthalimide Moiety and Photochromic Fluorescence Behaviors | Author : Ersin ORHAN | Abstract | Full Text | Abstract :The objective of the research was to synthesise new photo switchable photochromic fluorescence compounds. Starting from N-butyl-4-bromo-3-iodo-1,8-naphthalimide new compounds: 3,4-Bis(2-phenyl-5-methyl-4-thiazolyl)-N-butyl-1,8-naphthalimide 1O and 3,4-Bis(3,5-dimethyl-4-isoxazolyl)-N-butyl-1,8-naphthalimide 2O were prepared via two step Suzuki coupling reaction of aryl boronic acid and esters, and their photochromic fluorescence properties were investigated. Although all prepared bisaryl naphthlimides were fluorescence due to the naphthlimide moiety, among them photochrome 1O displayed photochromism. On exposure to ultraviolet light, the photochrome 1O showed a pale yellow to blue-green colour change due to the formation of ring closed form 1C, which reversed to the ring opened form 1O on exposure to visible light. Conversion ratio and quantum efficiency (from O to C form) for 1O were also determined.
Additionally, a solvent effect on the fluorescence properties of 1O and 2O was investigated. Increase of solvent polarity results in a red shift (to longer wavelengths) of the fluorescence emissions. |
| Using Natural Stone Pumice in Van Region on Adsorption of Some Textile Dyes | Author : Ali Riza KUL, Veysel BENEK, Ahmet SELÇUK, Nilgün ONURSAL | Abstract | Full Text | Abstract :Toxic effect of textile dyes their increasing quantities in air, soil and water environments, because of growing of industrial actives, they must be taken into consideration since they harm to environment. We come across textile dyes in natural wetlands as result of uncontrolled industrial wasted. Textile dyes that can accumulate easily in their environments may show toxic effects.
Pumice, accruing as result of volcanic events and durable against chemical factors, is a rock that has porous structure. Pumices have a porous structure because of sudden cooling of the rock and sudden leaving of gases a result of volcanic events. Thanks to these pores, pumices heat and sound insulation are quite high. The most distinctive feature of pumice from other rocks is that it has different colors and there is not crystal water in its porous structure.
Adsorption studies are applied with Van Pumice at pH = 6, the adsorption mechanism and changing metal concentration. As result of these researches, it has been found that there are different adsorption movements at pH 6 between textile dyes and Van Pumice. The result of this study shows that the Pumice found in Lake Van gives a better fit for the Langmuir Isotherm (model) and the amount of adsorption increases with the temperature.
It is thereby concluded that the Pumice located in Lake Van is a recommended adsorbent for filtering the used textile dye in aqueous medium.
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| Determination of Cd(II) Ions by using Cyclodextrin Based Polymeric Fluorescence Sensor | Author : Soner ÇUBUK, Özge YILMAZ, Ece KÖK YETIMOGLU, Memet Vezir KAHRAMAN | Abstract | Full Text | Abstract :In this study, Cd (II) ion was determined using a cyclodextrin-based polymeric fluorescence sensor prepared by UV-curing technique. The effects of several parameters such as pH, time, coexisting ions on the fluorescence intensity were also examined. The excitation and emission wavelengths were found to be 374 nm and 422 nm, respectively. The measurement range was in the range of 4.45x10-9 mol L-1 to 4.45x10-8 mol L-1 for Cd(II) ions and the detection limit was calculated as 6.23´10-10 mol L-1. In addition, sensor membrane was selective which was not influenced by common coexisting metal ions. The concentrations of the foreign ions such as Pb(II), Co(III), Ag(I), Zn(II), Cu(II), Cr(III) are 1000-fold higher than Cd(II) ions. Besides the prepared polymeric fluorescence sensor was successfully implemented to the determination of Cd(II)ions in biscuit and tap water samples. |
| CSA-Catalyzed Three-component Synthesis of Fused Polycyclic Pyrazolo[4,3-e]pyridines Under Ultrasonic Irradiation and Their Antioxidant Activity | Author : Emel PELIT | Abstract | Full Text | Abstract :New fused pyrazolo[4,3-e]pyridines were obtained by multi-component reaction of 1,3-dimethyl-1H-pyrazol-5-amine or 3-phenyl-1H-pyrazol-5-amine, aromatic aldehydes and indan-1,3-dione in the presence of camphor-10-sulfonic acid (CSA) as an effective catalyst under ultrasound promoted conditions. The antioxidant activity of the pyrazolopyridine compounds 4b, 5c, 5e, 7a, 7b and 7c were determined. |
| Synthesis and Characterization of Novel Aromatic Substituted ?- and d-Ketoxime Esters | Author : Belma HASDEMIR | Abstract | Full Text | Abstract :By starting their corresponding keto esters 1a-j, aryl-, substituted aryl- and heteroaryl-containing ?- and d-oximes 2a-2j (ten in total) were obtained. Proton nuclear magnetic resonance spectroscopy, carbon nuclear magnetic resonance spectroscopy, fourier transform infrared spectroscopy, mass spectrometry and elemental analyses were applied to the synthesized compounds for elucidating their structures and to find the (E)/(Z) isomerizations. |
| Fluorescence Sensor for the Determination of Boron | Author : Soner ÇUBUK, Mirgül KOSIF, Ece KÖK YETIMOGLU, Memet Vezir KAHRAMAN | Abstract | Full Text | Abstract :This study reports the preparation and characterization of a new polymeric fluorescence sensor for the determination of boron. The sensor was prepared by the UV-curing of Glucosyloxyethyl methacrylate (GOEM), 1,6-Hexandiol diacrylate (HDDA), hydroxyethylmethacrylate (HEMA) and 2,2’-dimethoxy-2-phenylacetophenone (DMPA) was used as the photoinitiator. The features of the sensor performance including sensitivity, response time, pH effect, stability and matrix interferences were studied. The excitation and emission wavelengths of the fluorescence sensor were 378 and 423 nm, respectively. With the prepared fluorescence sensor, the optimum pH value for the boron solution was determined as pH 6.0, and the optimum analysis time was selected as 45 seconds. The linear response range under the optimized conditions was found to be 9.25 × 10-7 mol L-1 and 9.25 × 10-6 mol L-1. The limit of detection (LOD) was 2.90 × 10-8 mol L-1 and the limit of quantification (LOQ) was 9.66 10-8 mol L-1 (n=7) with 1.2% relative standard deviation. In addition, boron could be selectively detected by the prepared polymeric sensor even in the presence of foreign ions. The prepared sensor was also successfully applied to real environmental water samples. |
| Chemical investigation and antioxidant activity of fractions of Lannea humilis (Oliv.) Engl. | Author : Jonathan ACHIKA, Racheal AYO, Adebayo OYEWALE, Dama JAMES | Abstract | Full Text | Abstract :The assessment of secondary metabolites shows the availability of steroids, terpenes, glycosides, saponins, tannins, flavonoids, alkaloids, and carbohydrate in the extracts of the stem bark of Lannea humilis. Steroids and terpenes were available in the hexane, ethyl acetate and methanol fraction, while tannins, flavonoids and alkaloids were available in the ethyl acetate and methanol extract. Carbohydrate and saponins were available just in the methanol division. The antioxidant activity of these plant extracts demonstrated a dose-dependent increment. The ethyl acetate extract displayed most noteworthy antioxidant activity of 98% at 240 µg/ml, followed by the hexane extract which had a percentage antioxidant activity of 92 % at 240 µg/ml. The methanol extract demonstrated percentage antioxidant activity of 71 % at 240 µg/ml. These results demonstrated that this plant can be used as a good antioxidant. |
| Theoretical Investigation of Corrosion Inhibition of Iron Metal by Some Benzothiazole Derivatives: A Monte Carlo Study | Author : Nail ALTUNAY, Savas KAYA | Abstract | Full Text | Abstract :It is important to note that atomistic modeling and simulations are becoming increasingly popular in the field of corrosion inhibition of metal surfaces. In this work, we investigated the adsorption properties and corrosion inhibition efficiencies of some benzothiazole derivatives (ABT, TCHBT, TSCBT) against the corrosion of iron metal using molecular dynamics simulation approach. It is important to note that adsorption and binding energies calculated considering adsorption processes on Fe metal surface of aforementioned inhibitor molecules are in good agreement with experimental data reported earlier. |
| A versatile water soluble ball-type phthalocyanine as potential antiproliferative drug: the interaction with G-quadruplex formed from Tel 21 and cMYC | Author : Efkan BAGDA, Esra BAGDA, Ebru YABAS | Abstract | Full Text | Abstract :G-quadruplexes are biologically important DNA conformations exist generally in guanine rich segments of DNA, such as telomere and proto-oncogene.
The formation of these secondary structures is thought to inhibit the expression of certain genes, such as the inhibition of telomerase. The inhibition of telomerase and suppression of a specific gene expression are important approaches for interruption of cancer cells proliferation. In the present study, the effect of a versatile water soluble ball-type phthalocyanine on G-quadruplex formation and stabilization was investigated to demonstrate its potential usage in cancer chemotherapy. Two important guanine rich oligomers, cMYC and Tel 21 were used as G-quadruplex former sequence. To the best of our knowledge, this is the first study about the interaction of a ball-type phthalocyanine; with G-quadruplex structures. The interactions of the compound; with G-quadruplex molecules were monitored spectrophotometrically. The structural differentiations of G-quadruplex after binding were investigated; with circular dichroism spectrophotometry. The replacement ability of the molecule; with a known DNA binding molecule, ethidium bromide, was clarified fluorometrically. The Stern-Volmer studies were conducted for determination of the quenching mechanism. The strong interaction of the molecules -ball-type phthalocyanine; with oligomer- showed us the potential usage of these drug conjugates for targeted photodynamic therapy in the future. |
| Novel Straight-chained Sulfanyl Members of Arylamino-1,4-naphthoquinones: Synthesis and Characterization | Author : Nilufer BAYRAK | Abstract | Full Text | Abstract :The aim of this paper is to describe the synthesis and characterization of new members of straight-chained sulfanyl derivatives of arylamino-1,4-naphthoquinones. 2-(4-(trifluoromethyl)phenylamino)-3-chloronaphthalene-1,4-dione (3a) and 2-(3-(trifluoromethyl)phenylamino)-3-chloronaphthalene-1,4-dione (3b) compounds which prepared by means of nucleophilic substitution reactions between 2,3-dichloro-1,4-naphthoquinone (1) and arylamines containing trifluoro group at meta and para positions (2a, 2b) were used as building blocks for straight-chained sulfanyl arylamino-1,4-naphthoquinones. The structures of all the novel compounds (5a-f) were established by spectroscopic evidence including IR, 1H NMR, 13C NMR, and MS data.
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| Determination of bisphenol A in plastic bottle packaging beverage samples using ultrasonic-assisted extraction and flame atomic absorption spectrometr | Author : Emre YILDIRIM, Nail ALTUNAY, Ramazan GÜRKAN | Abstract | Full Text | Abstract :In this work, a versatile and simple ultrasound-assisted extraction (UAE) procedure, which provides high separation efficiency for bisphenol A, was developed for its indirect determination in beverages in contact with plastic containers by flame atomic absorption spectrometry (FAAS). The method is based on charge transfer reaction, in which bisphenol A reacts with Cu(II) in alkaline tartrate solutions of pH 8.0 to produce Cu(I), which reacts with ion-pairing reagent, promethazine being a phenothiazine derivative (PMZ), in presence of cetyltrimethylammonium bromide (CTAB). For the indirect determination of bisphenol A using FAAS, the signal change of Cu(II) was investigated in detail depending on bisphenol A concentration. At optimal conditions, the analytical features of the method were obtained as follows; linear ranges of 1.5-100 µg L-1 for direct aqueous calibration solutions and 3-125 µg L-1 for matrix matched calibration solutions;the limits of detection and quantification of 0.47 and 1.56 µg L-1; sensitivity enhancement and preconcentration factors of 135 and 150, respectively. The validity of method was tested by repeatability/reproducibility precision studies using standard addition method. As the last, the method was successfully applied to determination of bisphenol A in selected samples. |
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