Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- 1 (98)
- 2 (82)
- Synthesis (60)
- Adsorption (52)
- Antimicrobial activity (47)
-
- 3 (44)
- Phthalocyanine (34)
- Antibacterial activity (29)
- Cytotoxicity (27)
- Molecular docking (26)
- Preconcentration (26)
- Palladium (25)
- Voltammetry (25)
- Cyclic voltammetry (24)
- Copper (23)
- Fluorescence (23)
- Schiff base (23)
- Lamiaceae (22)
- Spectrophotometry (22)
- Antioxidant activity (19)
- DFT (19)
- Kinetics (19)
- Chitosan (18)
- Nanoparticles (18)
- Cadmium (17)
- Antioxidant (16)
- Electrospinning (16)
- Photocatalysis (16)
- 4-triazole (15)
- Antimicrobial (15)
- Publication Year
Articles 2161 - 2190 of 2628
Full-Text Articles in Physical Sciences and Mathematics
6-O-\Alpha-L-Rhamnopyranosylcatalpol Derivative Iridoids From Verbascum Cilicicum, İ. İrem Tatli, Zeli̇ha Ş. Akdemi̇r, Erdal Bedi̇r, Ikhlas A. Khan
6-O-\Alpha-L-Rhamnopyranosylcatalpol Derivative Iridoids From Verbascum Cilicicum, İ. İrem Tatli, Zeli̇ha Ş. Akdemi̇r, Erdal Bedi̇r, Ikhlas A. Khan
Turkish Journal of Chemistry
From the aerial parts of Verbascum cilicicum Boiss., 6 iridoid glycosides, namely catalpol (1), verbaspinoside [= 6-O-(2'' -O-trans-cinnamoyl)-\alpha-L-rhamnopyranosylcatalpol] (2), 6-O-(3''-O-trans-cinna\-moyl)-\alpha-L-rhamnopyranosylcatalpol (3), 6-O-(4''-O-trans-cinnamoyl)-\alpha -L-rhamnopyranosylcatalpol (4), saccatoside [= 6-O-(2''-O-trans-p-coumaroyl)-\alpha-L-rhamnopyranosylcatalpol] (5), and 6-O-(3''-O-trans-p-coumaroyl)-\alpha-L-rhamnopyranosylcatalpol (6), were isolated. The structures of the compounds were elucidated by means of 1 and 2 dimensional (DQF-COSY, HMQC and HMBC) NMR techniques and LC-ESIMS.
Plasticiser Effect On Water Vapour Permeability Properties Of Locust Bean Gum--Based Edible Films, Özgür Altan Bozdemi̇r, Mehmet Tutaş
Plasticiser Effect On Water Vapour Permeability Properties Of Locust Bean Gum--Based Edible Films, Özgür Altan Bozdemi̇r, Mehmet Tutaş
Turkish Journal of Chemistry
The barrier properties of edible films prepared from polysaccharide polymer (locust bean gum) and various plasticisers (glycerol, propylene glycol, sorbitol, and polyethylene glycol 200) together with hydrophobic modifiers (stearopten and beeswax) were examined. It was determined that the films containing polyethylene glycol 200 (PEG 200) and sorbitol have the lowest water vapour permeability values and the films containing glycerol have the highest WVP values. It was found that the most reasonable of the studied plasticisers was PEG 200. Polysaccharide--based edible films have higher WVP values than those of lipid-- and protein--based edible films. In order to reduce the WVP of …
Photochemical Reactions Of \Alpha-Terpinene And Acenaphthene Under Concentrated Sunlight, Nesi̇be Avcibaşi, Siddik İçli̇, Andrew Gilbert
Photochemical Reactions Of \Alpha-Terpinene And Acenaphthene Under Concentrated Sunlight, Nesi̇be Avcibaşi, Siddik İçli̇, Andrew Gilbert
Turkish Journal of Chemistry
\alpha-Terpinene was successfully dehydrogenated to p-cymene in photocatalytic reaction with benzophenone and cupric ions under 40 suns concentrated sunlight irradiation, proving that photodehydrogenation reactions may be employed for the synthesis of fine chemicals under sunlight. Acenaphthene dehydrogenation under concentrated sunlight resulted in the minor formation of acenaphthylene and the quantitative formation of acenaphthenone when the solution was aerated. Stable benzylic-type radical intermediates are thought to lower the yield of dehydrogenation reactions.
Purification And Partial Characterization Of Catalase From Chicken Erythrocytes And The Effect Of Various Inhibitors On Enzyme Activity, Tüli̇n Aydemi̇r, Kevser Kuru
Purification And Partial Characterization Of Catalase From Chicken Erythrocytes And The Effect Of Various Inhibitors On Enzyme Activity, Tüli̇n Aydemi̇r, Kevser Kuru
Turkish Journal of Chemistry
Catalase plays a major role in the protection of tissues from the toxic effects of H_{2}O_{2} and partially reduced oxygen species. A nearly 136-fold enzyme purification was obtained from chicken erythrocyte by acetone precipitation, ethanol-chloroform treatment, CM-cellulose and Sephadex G-200 chromatography. The specific activity of purified enzyme was 42,556 U/mg. The molecular weight of the native chicken erythrocyte catalase was estimated at 240 kDa by gel filtration. SDS-gel electrophoresis results indicated that chicken erythrocyte catalase consists of four apparently identical subunits, with a molecular weight of around 57.5 kDa. The optical spectrum of the purified enzyme shows a Soret band …
A Novel Silver Recovery Method From Waste Photographic Films With Naoh Stripping, Nuri̇ Naki̇boğlu, Duygu Toscali, Gürel Ni̇sli̇
A Novel Silver Recovery Method From Waste Photographic Films With Naoh Stripping, Nuri̇ Naki̇boğlu, Duygu Toscali, Gürel Ni̇sli̇
Turkish Journal of Chemistry
A novel, simple, fast, cheap and pollution-free method was developed for recovering the silver from waste X-ray photographic films with NaOH stripping. The method has a number of advantages because it obviates the need for burning, oxidizing, electrolysis or purifying steps. Moreover, all experiments were carried out in the same flask, unlike other techniques. Silver recovery conditions were optimized and silver a purity level of 99\% was recovered. The metal impurities (Al, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Sn) in the recovered silver were determined using the ICP-MS method. The results were compared with results in …
Studies On The Mechanism Of Base-Catalyzed Decomposition Of Bicyclic Endoperoxides, Ebru Mete, Ramazan Altundaş, Hasan Seçen, Meti̇n Balci
Studies On The Mechanism Of Base-Catalyzed Decomposition Of Bicyclic Endoperoxides, Ebru Mete, Ramazan Altundaş, Hasan Seçen, Meti̇n Balci
Turkish Journal of Chemistry
Kinetic studies were performed to clarify the Kornblum-Delamare reaction mechanism of bicyclic endoperoxides. Ascaridol and 1,4-diphenyl-2,3-dioxa-bicyclo[2.2.2]oct-5-ene, not having \alpha -protons, did not provide any reaction with bases. Reaction with different bases has revealed that reaction rates for the base-catalyzed decomposition of 2,3-dioxa-bicyclo[2.2.2]oct-5-ene depend strongly on the base strength. The stronger the base used, the faster the conversion rate. Reaction rate values k of endoperoxides with different skeletons were also studied with NEt_{3}. It has been noted that the strength of the base plays the dominant role in determining the rate of the reactions.
The Kinetic Study Of The Chemical Oscillating System Of 1,3-Propanediol/Acetone As The Organic Substrate, Shi-Gang Shen, Caiqin Yang, Han-Wen Sun, Jin-Huan Shan, Ying Liu
The Kinetic Study Of The Chemical Oscillating System Of 1,3-Propanediol/Acetone As The Organic Substrate, Shi-Gang Shen, Caiqin Yang, Han-Wen Sun, Jin-Huan Shan, Ying Liu
Turkish Journal of Chemistry
This work was primarily an experimental investigation of the bromate oscillator using 1,3-propanediol and acetone as the mixed organic substrates. The empirical equation of the induction period and oscillating period with the concentrations of the reactants and temperature were obtained. The oscillating characteristic and possible oscillation mechanism were studied.
A Study On The Fatty Acid Composition Of Fish Liver Oil From Two Marine Fish, Eusphyra Blochii And Carcharhinus Bleekeri, Zafar S. Saify, Shamim Akhtar, Khalid Mohammed Khan, Shahnaz Perveen, Syed Abdul Majid Ayattollahi, Sohail Hassan, M. Arif, Syed Moazzam Haider, Faheem Ahmad, Sazada Siddiqui, Mohammeda Zarrar Khan
A Study On The Fatty Acid Composition Of Fish Liver Oil From Two Marine Fish, Eusphyra Blochii And Carcharhinus Bleekeri, Zafar S. Saify, Shamim Akhtar, Khalid Mohammed Khan, Shahnaz Perveen, Syed Abdul Majid Ayattollahi, Sohail Hassan, M. Arif, Syed Moazzam Haider, Faheem Ahmad, Sazada Siddiqui, Mohammeda Zarrar Khan
Turkish Journal of Chemistry
Two species of shark found in the coastal waters Karachi (Pakistan) were studied, Eusphyra blochii (winghead snark) and Carcharhinus bleekeri (sandbar shark) for their liver oil fatty acid composition. Since liver has high lipid content and traditionally the liver oil of these species been used to relieve muscular pain and arthritis in Pakistan this study was conducted. The isolation, identification and characterization of these fatty acids were carried out by gas liquid chromatography (GLC) and a combination of the thin layer chromatography (TLC)-GLC technique. A large variation was observed between winghead shark liver oil and sandbar shark liver oil. Twenty-five …
Crystal Structure Of Cis-Bis(N,N-Dimethyl-N'-Benzoylthioureato)Palladium(Ii), Göktürk Avşar, Hakan Arslan, Hans-Jurgen Haupt, Nevzat Külcü
Crystal Structure Of Cis-Bis(N,N-Dimethyl-N'-Benzoylthioureato)Palladium(Ii), Göktürk Avşar, Hakan Arslan, Hans-Jurgen Haupt, Nevzat Külcü
Turkish Journal of Chemistry
In this study cis-bis(N,N-dimethyl-N'-benzoylthioureato) palladium(II) is synthesised and the crystal structure is determined by X-ray diffraction methods. It crystallises in the space group P2_{1}/c, with a = 11.943(1) Å, b = 11.713(1) Å, c = 15.345(1) Å, \beta = 93.90(1)°, and D_{calc} = 1.616 g cm^{-1} for Z = 4. The Pd(II) atom is in a four-coordinate geometry consisting of two thiocarbonyl S and two carbonyl O atoms from two ligand groups. The Pd-S and Pd-O bond lengths are 2.2313(6) and 2.0211(16) Å, respectively.
Iridoid And Phenylpropanoid Glycosides From Phlomis Samia, P. Monocephala And P. Carica, Funda Nuray Yalçin, Tayfun Ersöz, Pinar Akbay, İhsan Çaliş, Ali̇ Arslan Dönmez, Otto Sticher
Iridoid And Phenylpropanoid Glycosides From Phlomis Samia, P. Monocephala And P. Carica, Funda Nuray Yalçin, Tayfun Ersöz, Pinar Akbay, İhsan Çaliş, Ali̇ Arslan Dönmez, Otto Sticher
Turkish Journal of Chemistry
From the aerial parts of Phlomis samia an iridoid glucoside, shanzhiside methylester (1), and three phenylethanoid glycosides, martynoside (2), 4''-O-acetylmartynoside (3) and samioside (4), were isolated. From the overground parts of P. monocephala two iridoid glucosides, lamiide (5) and ipolamiide (6), as well as three phenylethanoid glycosides, verbascoside (= acteoside) (7), forsythoside B (8), alyssonoside (9), and one lignan glucoside, syringaresinol 4'-O-\beta -D-glucopyranoside (10), were isolated. From the aerial parts of P. carica one phenylethanoid glycoside, verbascoside (= acteoside) (7) and three phenylpropanoid monomeric glucosides, syringin (11), dihydrosyringin (12) and coniferin (13), were isolated. The structures of the isolated compounds …
Application Of A Three-Stage Sequential Extraction Procedure For The Determination Of Extractable Metal Contents In Highway Soils, Şeri̇fe Tokalioğlu, Şenol Kartal, Gökhan Bi̇rol
Application Of A Three-Stage Sequential Extraction Procedure For The Determination Of Extractable Metal Contents In Highway Soils, Şeri̇fe Tokalioğlu, Şenol Kartal, Gökhan Bi̇rol
Turkish Journal of Chemistry
A sequential extraction procedure, a three-step protocol proposed by the Standards, Measurements and Testing programme (SM & T--formerly BCR) of the European Union, was applied to soil samples for the determination of metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn). This procedure provides measurements of extractable metals from media such as acetic acid (0.11 mol L^{-1}), hydroxylammonium chloride (0.1 mol L^{-1}) and hydrogen peroxide (8.8 mol L^{-1}) plus ammonium acetate (1 mol L^{ - 1}), which are exchangeable, reducible and oxidisable metals, respectively. Analyses were carried out using flame atomic absorption spectrometry (FAAS). The results obtained from …
Aluminum Fractionation In The Water Of Karakaya Dam Lake (Malatya, Turkey), F. Zehra Küçükbay, Mustafa Demi̇r
Aluminum Fractionation In The Water Of Karakaya Dam Lake (Malatya, Turkey), F. Zehra Küçükbay, Mustafa Demi̇r
Turkish Journal of Chemistry
A method was developed for the determination of trace amounts of Al species in water samples using the amberlite type XAD-4 resin. For this purpose, total dissolved Al, organically bonded Al and particulate Al in water samples taken from Karakaya dam lake (Malatya, Turkey) were determined by flame atomic absorption spectroscopy (FAAS) or graphite furnace atomic absorption spectroscopy (GFAAS) after an enrichment procedure. The total dissolved Al in the water samples was determined using 8-hydroxyquinoline as complexing reagent at pH 8 and amberlite type XAD-4 resins for the enrichment. The organically bonded Al species in the water samples were destroyed …
Purification And Characterization Of Glucose 6-Phosphate Dehydrogenase From Sheep Liver, Vedat Türkoğlu, Si̇nan Aldemi̇r, Mehmet Çi̇ftçi̇
Purification And Characterization Of Glucose 6-Phosphate Dehydrogenase From Sheep Liver, Vedat Türkoğlu, Si̇nan Aldemi̇r, Mehmet Çi̇ftçi̇
Turkish Journal of Chemistry
Glucose 6-phosphate dehydrogenase (D-glucose 6-phosphate: NADP^{+} oxidoreductase, EC 1.1.1.49; G6PD) was purified from sheep liver by a simple and rapid method. The purification process consisted of two steps: preparation of the homogenate, and 2', 5'-adenosine diphosphate (ADP) Sepharose 4B affinity chromatography. Through the use of these two consecutive steps, the enzyme was purified with a yield of 35.6% and 1,920 fold, having the specific activity of 11.2 enzyme units (EU/mg protein). A K_{M} of 0.176 mM and a V_{\max} of 0.0179 EU/ml were obtained for G6-P, and 0.0194 mM and 0.0223 EU/ml for NADP^{+}. Enzymatic activity was measured spectrophotometrically according …
Preparation And Characterization Of Conducting Polybutadiene/ Polythiophene Composites, Senem Kiralp, Zuhal Küçükyavuz, Atef F. Qasrawi
Preparation And Characterization Of Conducting Polybutadiene/ Polythiophene Composites, Senem Kiralp, Zuhal Küçükyavuz, Atef F. Qasrawi
Turkish Journal of Chemistry
Conductive composite films of cis-1,4-polybutadiene (PBD) with polythiophene (PTh) were prepared electrochemically. Thiophene was polymerized on PBD-coated platinium electrodes. The composites with different PTh percentages showed conductivity in the order of 10^{-3} (\Omega cm)^{-1}. The characterization of the films was performed using FTIR, scanning electron microscope and differential scanning calorimetry techniques. In order to understand the dominant transport mechanism, the temperature dependence of conductivity was investigated.
Some Polyamidoxime Derivatives And Their Metal Complexes, Fatma Kari̇pci̇n, İbrahi̇m Karataş, Hali̇l İsmet Uçan
Some Polyamidoxime Derivatives And Their Metal Complexes, Fatma Kari̇pci̇n, İbrahi̇m Karataş, Hali̇l İsmet Uçan
Turkish Journal of Chemistry
In this paper the synthesis of six polyamidoximes from their corresponding diamines with 4,4'-methylenebis (phenylglyoxylohydroximoyl chloride) and 4,4'-methylenebis(chlorophenylgly-oxime) is presented. The average molecular weights of these organic polymers were determined. In addition, the complexes of 4,4'-methylenebis (phenylglyoxylohydroximoyl chloride) with Ni(II), Co(II) and Cu(II) salts were prepared. The structures of these compounds were identified by IR or ^{1}H NMR spectral data, elemental analyses, magnetic measurements and thermal analysis.
Synthesis Of New 4-(5-Chloro-2-Oxo-3h-Benzoxazol-3-Yl)Butanamide Derivatives And Their Analgesic And Anti-Inflammatory Properties, H. Ozan Gülcan, Serdar Ünlü, Erden Banoğlu, M. Fethi̇ Şahi̇n, Esra Küpeli̇, Erdem Yeşi̇lada
Synthesis Of New 4-(5-Chloro-2-Oxo-3h-Benzoxazol-3-Yl)Butanamide Derivatives And Their Analgesic And Anti-Inflammatory Properties, H. Ozan Gülcan, Serdar Ünlü, Erden Banoğlu, M. Fethi̇ Şahi̇n, Esra Küpeli̇, Erdem Yeşi̇lada
Turkish Journal of Chemistry
In this preliminary screening study for developing potent analgesic and anti-inflammatory compounds, eight new 4-(5-chloro-2-oxo-3H-benzoxazol-3-yl)butanamide derivatives were synthesized and screened for their analgesic and anti-inflammatory activities as well as gastric ulceration potential in tested animals. Their structures were elucidated by their IR, ^{1}H-NMR and elemental analysis. All of the compounds exhibited high analgesic and anti-inflammatory activities. None of the compounds except compound 2g caused gastric lesions or bleeding in tested animals.
Isolation And Structure Elucidation Of Novel Natural Products From Turkish Lichens, Süheyla Kirmizigül, Ömer Koz, Hüseyi̇n Anil, Siddik İçli̇, Ulvi̇ Zeybek
Isolation And Structure Elucidation Of Novel Natural Products From Turkish Lichens, Süheyla Kirmizigül, Ömer Koz, Hüseyi̇n Anil, Siddik İçli̇, Ulvi̇ Zeybek
Turkish Journal of Chemistry
Three natural products were isolated from three different Turkish lichens. Microbiological investigations were also examined of these lichens. Compound 1 is known as 2-hydroxy-4-methoxy-3,6-dimethyl benzoic acid, and is isolated from Pseudevernia furfuracea for the first time. Compounds 2 and 3 are detected as new compounds and called, 3-acetyl-4-amino-2-chloro-1- (4-hydroxy-2-methoxy- 6-methylphenyl carbonyloxy) benzene and 2-(4-methoxyphenyl)-2-(5-oxo-4-phenyl-2,5- dihydro-2-furaniliden) acetic acid; they were isolated from Evernia prunastri and Letharia vulpina, respectively. All these compounds had different skeletons. Their structures were established by chemical methods and spectroscopic techniques using IR, UV, 1D and 2D NMR and EI and (+) FAB-Mass methods.
Catalytic Spectrophotometric Determination Of Manganese In Some Medicinal Plants And Their Infusions, Kostantin L. Mutaftchiev
Catalytic Spectrophotometric Determination Of Manganese In Some Medicinal Plants And Their Infusions, Kostantin L. Mutaftchiev
Turkish Journal of Chemistry
The catalytic effect of manganese (II) on the oxidation of the dye 1,3-Dimethyl- 2 [4-N (N,N-dimethylamino) phenylazo] imidazolium perchlorate (BR) with potassium periodate in the presence of 1,10-phenanthroline was investigated. The reaction was followed spectrophotometrically by measuring the decrease in the absorbance of the dye at 540 nm. Under optimum conditions (5 \times 10^{-5} mol dm^{-3} BR, 2 \times 10^{-4} mol dm^{-3} potassium periodate, 1 \times 10^{-4} mol dm^{-3} 1,10-phenanthroline, 0.1 mol dm^{-3} buffer -- pH 3.0, 70 °C, 5 min) manganese (II) in the range 0.1--4.5 ng cm^{-3} can be determined by the fixed-time method with a detection limit …
Study On Papain Immobilization On A Macroporous Polymer Carrier, Liang Ding, Zihua Yao, Tong Li, Qiang Yue, Jia Chai
Study On Papain Immobilization On A Macroporous Polymer Carrier, Liang Ding, Zihua Yao, Tong Li, Qiang Yue, Jia Chai
Turkish Journal of Chemistry
Macroporous resin microbeads of methyl methacrylate-divinyl benzene copolymer were synthesized by radical suspension polymerization of acrolein with divinylbenzene in the presence of a pore-creating agent, petroleum ether. The microbeads had a large specific surface area and large pores covered the entire surface of the resin. This macroporous polymer carrier was aminated by hydrazine hydrate that produced a large number of amino groups on the carrier. Papain was immobilized on the porous polymer carrier by glutaraldehyde cross-linking or diazo-coupling. The factors involved in the activity recovery of the immobilized papain and the enzymic properties of the resulting immobilized papain were studied …
Phenolic, Megastigmane, Nucleotide, Acetophenon And Monoterpene Glycosides From Phlomis Samia And P. Carica, Funda Nuray Yalçin, Tayfun Ersöz, Pinar Akbay, İhsan Çaliş, Ali̇ Arslan Dönmez, Otto Sticher
Phenolic, Megastigmane, Nucleotide, Acetophenon And Monoterpene Glycosides From Phlomis Samia And P. Carica, Funda Nuray Yalçin, Tayfun Ersöz, Pinar Akbay, İhsan Çaliş, Ali̇ Arslan Dönmez, Otto Sticher
Turkish Journal of Chemistry
Phytochemical investigations on the aerial parts of Phlomis samia resulted in the isolation of a simple phenolic glucoside, 2,6-dimethoxy-4-hydroxyphenol-1-O-\beta -D-glucopyranoside (1); a megastigmane glucoside, phlomuroside (=3-hydroxy-5,6-epoxy-\beta -ionol-9-O-\beta -D-glucopyranoside) (2); and a nucleotide glycoside, uridine (3). From the aerial parts of P. carica, the same phenolic glucoside, 2,6-dimethoxy-4-hydroxyphenol-1-O-\beta -D-glucopyranoside (1); as well as an acetophenon glucoside, picein (4); and 2 monoterpenoid glucosides, - betulalbuside A (5) and 1-hydroxylinaloyl-6-O-\beta -D-glucopyranoside (6) - were isolated and identified. The structure elucidation of the isolates was based on spectroscopic evidence.
Application Of Ibx Method For The Synthesis Of Ketones From Carboxylic Acids, H. R. Ferhat Karabulut, Mesut Kaçan, Hasan Özyildirim
Application Of Ibx Method For The Synthesis Of Ketones From Carboxylic Acids, H. R. Ferhat Karabulut, Mesut Kaçan, Hasan Özyildirim
Turkish Journal of Chemistry
Methoxy phenyl propionic acid and some derivatives are converted to ketones using a new method. All classical methods to obtain ketones from carboxylic acids via acid halide consistently gave very low yields and regularly generated intermolecular cyclisation products or polymeric materials. However, high ketones yields are obtained by using the new IBX method.
Neolignan, Flavonoid, Phenylethanoid And Iridoid Glycosides From Phlomis Integrifolia, İclal Saracoğlu, Mehtap Varel, İhsan Çaliş, Ali̇ Arslan Dönmez
Neolignan, Flavonoid, Phenylethanoid And Iridoid Glycosides From Phlomis Integrifolia, İclal Saracoğlu, Mehtap Varel, İhsan Çaliş, Ali̇ Arslan Dönmez
Turkish Journal of Chemistry
From the aerial parts of Phlomis integrifolia Hub.-Mor. (Lamiaceae) were isolated a neolignan glucoside, dehyrodiconiferyl alcohol-4-O-\beta -D-glucopyranoside (1), an ester flavone glycoside, chrysoeriol 7-O-(3''-O-trans-p-coumaroyl)-\beta -D-glucopyranoside (2), four phenylethanoid glycosides, forsythoside B (3), verbascoside (=acteoside) (4), leucosceptoside A (5) and martynoside (6) along with an iridoid glucoside, lamiide (7). The structure elucidation of the isolated compounds was carried out by spectroscopic (UV, IR, 1D- and 2D-NMR) methods. The isolation of neolignan glucoside dehyrodiconiferyl alcohol-4-O-\beta -D-glucopyranoside (1) is reported for the first time from a Phlomis species as well as for the family Lamiaceae.
Effects Of Ozonation On Characteristics Of Aquatic Fulvic Acid, Şermi̇n Gül
Effects Of Ozonation On Characteristics Of Aquatic Fulvic Acid, Şermi̇n Gül
Turkish Journal of Chemistry
Aquatic fulvic acid (FA) treated with ozone was characterized by physical/chemical (dissolved organic carbon-DOC), spectroscopic (UV/VIS, IR, fluorescence), chromatographic (gel permeation chromatography-GPC) methods. The influence of ozonation on the subsequent water treatment process such as flocculation and chlorination was also examined. The DOC concentration of the 20 min ozonated FA samples was reduced only a small amount (5%) whereas the UV absorption reduced to a higher percent (40%). The IR spectra of ozonated samples showed a moderate attenuation of the double band and aromatic character of FA. Ozonation of the FA caused the fluorescence intensities to increase steadily with ozonation …
Novel Method For The Spectrophotometric Determination Of Isoniazid And Ritodrine Hydrochloride, Padmarajaiah Nagaraja, Kallanchira Sunitha, Ramanathapura Vasantha, Hemmige Yathirajan
Novel Method For The Spectrophotometric Determination Of Isoniazid And Ritodrine Hydrochloride, Padmarajaiah Nagaraja, Kallanchira Sunitha, Ramanathapura Vasantha, Hemmige Yathirajan
Turkish Journal of Chemistry
A simple, rapid and sensitive spectrophotometric method for the determination of isoniazid (INH) and ritodrine hydrochloride (RTH) in pure form as well as dosage forms is described. The method is based on the diazotisation of 4,4'-sulphonyldianiline (dapsone, DAP) followed by a coupling reaction with either INH or RTH in sodium hydroxide medium. Beer's law is obeyed in the concentration range of 0.5-20 \mu g ml^{-1} for INH at 440 nm and 0.5-18 \mu g ml^{-1} for RTH at 460 nm. The method is successfully employed for the determination of INH/RTH in pharmaceutical preparations and the results agree favourably with the …
Determination Of The Micropore Structures Of Activated Carbons By Adsorption Of Various Dyestuffs From Aqueous Solution, Fuat Güzel, İlhan Uzun
Determination Of The Micropore Structures Of Activated Carbons By Adsorption Of Various Dyestuffs From Aqueous Solution, Fuat Güzel, İlhan Uzun
Turkish Journal of Chemistry
In this study, some activated carbons prepared from sour cherry pits under various conditions were investigated. For comparison purposes, the commercial activated carbons Merck-2514 and Merck-2184 were used. The nitrogen adsorption isotherms at 77 K were used as reference for comparison, while p-nitrophenol, methylene blue, orange-II and victoria blue adsorptions were determined from aqueous solution at 298 K. It was clear from the specific surface area values obtained that the best activated carbon was obtained by activation for 4 hours following the chemical activation. Its adsorption properties are closer to the levels of the Merck commercial carbons. It was concluded …
Kinetic Spectrophotometric Determination Of Nanogram Levels Of Manganese (Ii) By Azo Dye -- Potassium Periodate -- 1,10-Phenanthroline System, Konstantin L. Mutaftchiev
Kinetic Spectrophotometric Determination Of Nanogram Levels Of Manganese (Ii) By Azo Dye -- Potassium Periodate -- 1,10-Phenanthroline System, Konstantin L. Mutaftchiev
Turkish Journal of Chemistry
The catalytic effect of manganese (II) on the oxidation of 3 - Methyl - 6 - (2 - hydroxyethoxy) - 2 - [2 - methoxy - 4 - N (N,N - diethylamino) phenylazo] benzothiazolium methylsulphate (MHMDPBM), with potassium periodate in the presence of 1,10-phenanthroline in weakly acidic media was studied. The reaction was followed spectrophotometrically by measuring the decrease in the absorbance of the dye at 560 nm. Under the optimum conditions (4x10^{- 5} mol dm^{- 3} MHMDPBM, 4x10^{- 4} mol dm^{- 3} potassium periodate, 1x10^{- 4} mol dm^{- 3} 1,10-phenanthroline, 0.1 mol dm^{- 3} buffer -- pH 3.0, 70^oC, …
Electrochemical Investigation Of 4'-Haloderivatives Of N,N-Dimethyl-4-Aminoazobenzene, Mustafa Uçar, Ali̇ Osman Solak, M. Levent Aksu, Mehmet Toy
Electrochemical Investigation Of 4'-Haloderivatives Of N,N-Dimethyl-4-Aminoazobenzene, Mustafa Uçar, Ali̇ Osman Solak, M. Levent Aksu, Mehmet Toy
Turkish Journal of Chemistry
In this study, the electrochemical behaviour of 4' -halogene-N,N-dimethyl-4-aminoazobenzene derivatives were investigated using various polarographic and voltammetric methods. The peak potentials of these derivatives were observed to shift towards negative values with increase in pH. The standard rate constants were determined with (Laviron technique) or without (Nicholson and Klingler-Kochi techniques) taking the adsorption phenomena into account. The diffusion coefficients were calculated from the cyclic voltammetric data using the method developed by Garrido. The amount of adsorbed substances (surface excess values) and transfer coefficients for the electron transfer were also determined. These compounds can be quantitatively determined between 1 x 10^{-5} …
Iridoid, Phenylethanoid And Monoterpene Glycosides From Phlomis Sieheana, Tayfun Ersöz, Ü. Şebnem Harput, İhsan Çaliş, Ali̇ Arslan Dönmez
Iridoid, Phenylethanoid And Monoterpene Glycosides From Phlomis Sieheana, Tayfun Ersöz, Ü. Şebnem Harput, İhsan Çaliş, Ali̇ Arslan Dönmez
Turkish Journal of Chemistry
From the aerial parts of Phlomis sieheana, an iridoid glucoside, ipolamiide (1), six phenylethanoid glycosides, acteoside (= verbascoside) (2), cis-acteoside (3), \beta-hydroxyacteoside (4), leucosceptoside A (5), martynoside (6), forsythoside B (7), and a monoterpene glycoside, betulalbuside A (8) were isolated and characterized. The structure elucidations of the isolated compounds were established on the basis of spectroscopic evidence.
Determination Of Trace Amounts Of Gold(Iii) Using Ethopropazine Hydrochloride And Isothipendyl Hydrochloride: A Spectrophotometric Study, Mahaveer B. Melwanki, Saraswati̇ P. Masti, Jaldappa Seetharamappa
Determination Of Trace Amounts Of Gold(Iii) Using Ethopropazine Hydrochloride And Isothipendyl Hydrochloride: A Spectrophotometric Study, Mahaveer B. Melwanki, Saraswati̇ P. Masti, Jaldappa Seetharamappa
Turkish Journal of Chemistry
Two simple, sensitive and accurate spectrophotometric methods have been proposed for the determination of micro amounts of gold (III) using ethopropazine hydrochloride (EPH) and isothipendyl hydrochloride (IPH). The methods are based on the oxidation of phenothiazines by gold (III) to give red radical cations having maximum absorption at 513 and at 512 nm with molar absorptivities of 2.0 X 10^{4} and 2.1 X 10^{4} l mol^{ - 1} cm^{ - 1} for EPH and IPH respectively. Beer's law is valid over the concentration range 0.5-14.1 mg l^{ - 1} for EPH and 0.5-14.5 mg l^{ - 1} for IPH. The …
Electron Ionization Mass Spectrometric Studies Of Homalicine Tertraacetate, Dihydrohomalicine Tetraacetate And Related Compounds, Nasim Hasan Rama, Muhammad Tahir Hussain
Electron Ionization Mass Spectrometric Studies Of Homalicine Tertraacetate, Dihydrohomalicine Tetraacetate And Related Compounds, Nasim Hasan Rama, Muhammad Tahir Hussain
Turkish Journal of Chemistry
Electron Ionization mass spectra of homalicine tetraacetate (3), dihydrohomalicine tetraaetate (4) and related compounds (5,6) are described with the help of EIMS. The molecular formulae are further confirmed by HREIMS peak matching of molecular ion peaks exhibited by EIMS.