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- Scrophulariaceae (6)
- 1 (4)
- 2 (4)
- Phenylethanoid glycosides (4)
- Cyclic oxalyl compounds (3)
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- Iridoid glucosides (3)
- 3 (2)
- 4 (2)
- 4-d] Pyridazinone (2)
- 4]triazole (2)
- 5-oxo-[1 (2)
- Antitumor activity (2)
- Preconcentration (2)
- Pyrazole (2)
- Pyrazolo [3 (2)
- Radical scavenging activity (2)
- Spectrophotometry (2)
- 1-(\beta-D-glucopyranosyl)- 8-hydroxy-3 (1)
- 1-naphthaldehyde (1)
- 2'-bipyridine ligand (1)
- 2-(2-quinolylazo)-5-diethylaminoaniline (1)
- 2-Benzothiazolinone (1)
- 2-Benzoxazolinone (1)
- 2-Ethyl-2-oxazoline (1)
- 2-Oxobenzothiazoline (1)
- 2-hydroxyethyl methacrylate (1)
- 3'-dicarboxyl-2 (1)
- 3-Dipolar cycloaddition (1)
- 3-diazepan derivatives (1)
- 3-hydroxy fatty acid derivatives (1)
Articles 31 - 60 of 80
Full-Text Articles in Physical Sciences and Mathematics
Naphthoquinones From The Roots Of Onosma Argentatum Hub.-Mor. (Boraginaceae), Ufuk Özgen, Maksut Coşkun, Cavi̇t Kazaz, Hasan Seçen
Naphthoquinones From The Roots Of Onosma Argentatum Hub.-Mor. (Boraginaceae), Ufuk Özgen, Maksut Coşkun, Cavi̇t Kazaz, Hasan Seçen
Turkish Journal of Chemistry
Onosma argentatum Hub.-Mor. is an endemic species growing in Turkey. In this study, the roots of O. argentatum were extracted with n-hexane-dichloromethane (1:1). The extract was separated on a silica gel column eluting with n-hexane-ethyl acetate by gradient elution. New naphthoquinone compounds (3 known and 1 new) were isolated and their structures were elucidated by spectroscopic methods as deoxyshikonin, acetyl shikonin, 3-hydroxy-isovaleryl shikonin, and 5,8-O-dimethyl acetyl shikonin.
Synthesis And Antinociceptive Activity Of 2-[(2-Oxobenzothiazolin-3-Yl)Methyl]- 5-Aminoalkyl/Aryl-1,3,4-Thiadiazole, Ti̇jen Önkol, Bi̇lge Çakir, M. Fethi̇ Şahi̇n, Engi̇n Yildirim, Kevser Erol
Synthesis And Antinociceptive Activity Of 2-[(2-Oxobenzothiazolin-3-Yl)Methyl]- 5-Aminoalkyl/Aryl-1,3,4-Thiadiazole, Ti̇jen Önkol, Bi̇lge Çakir, M. Fethi̇ Şahi̇n, Engi̇n Yildirim, Kevser Erol
Turkish Journal of Chemistry
Ten 2-[(2-oxobenzothiazolin-3-yl)methyl]-5-aminoalkyl/aryl-1,3,4-thiadiazole derivatives were synthesized. The chemical structures of these compounds were elucidated by their FT-IR and ^1H-NMR spectral data, as well as their elemental analyses. The compounds were tested for antinociceptive activity. Among these compounds, 2-[(2-oxobenzothiazolin-3-yl)methyl]-5-aminomethyl-1,3,4-thiadiazole (5a) was found to be significantly more active than the others and the standards in all the tests.
Thermally Induced Cationic Polymerization Of 2-Ethyl-2-Oxazoline By Benzyl Pyridinium And Anilinium Salts, Hali̇l Ki̇rli̇bal, Yusuf Yağci
Thermally Induced Cationic Polymerization Of 2-Ethyl-2-Oxazoline By Benzyl Pyridinium And Anilinium Salts, Hali̇l Ki̇rli̇bal, Yusuf Yağci
Turkish Journal of Chemistry
N-Benzyl pyridinium (BP), N-benzyl o-cyano pyridinium (BoCP), N-benzyl p-cyanopyridinium (BpCP), N-benzyl N, N-dimethyl anilinium (BDA) and benzyl triphenyl phosphonium (BTP) salts with bromide counter anion, thermal initiators for cationic polymerization, were synthesized and characterized. Their capability to act as initiators for the polymerization of 2-ethyl-2-oxazoline (EOZO) was examined. The postulated mechanism is based on the generation of benzyl bromide by the thermolysis of either BoCP or BDA that reacts with the monomer, EOZO. The polymerization proceeds via an oxazolonium bromide as the propagating end. BP, BoCP and BTP were found to be unreactive towards EOZO.
The Hydrodynamic Properties Of Micelles Formed By Block Copolymers Of Isoprene And Tert-Butylacrylate In N-Octane, Hali̇l İbrahi̇m Ünal, Colin Price
The Hydrodynamic Properties Of Micelles Formed By Block Copolymers Of Isoprene And Tert-Butylacrylate In N-Octane, Hali̇l İbrahi̇m Ünal, Colin Price
Turkish Journal of Chemistry
The hydrodynamic properties of micelles formed by 2 block copolymers of isoprene and tert-butylacrylate in n-octane were investigated by dynamic light scattering (DLS) over a range of temperatures and concentrations using both the cumulants and histogram methods. By means of the histogram method it was possible to determine the average hydrodynamic diameters of both micelles and unassociated-chains in the same solution. It was also used to determine the z-average fraction of unassociated-chains at a particular concentration and temperature, and it provided an alternative route when combined with static light scattering (SLS) for determining the thermodynamics of micellisation. The overall-average diffusion …
Genetic Multivariate Calibration Methods For Near Infrared (Nir) Spectroscopic Determination Of Complex Mixtures, Durmuş Özdemi̇r, Betül Öztürk
Genetic Multivariate Calibration Methods For Near Infrared (Nir) Spectroscopic Determination Of Complex Mixtures, Durmuş Özdemi̇r, Betül Öztürk
Turkish Journal of Chemistry
The simultaneous determination of ternary mixtures of methylene chloride, ethyl acetate, and methanol using near infrared (NIR) spectroscopy and 4 different genetic algorithms based multivariate calibration methods was demonstrated. The 4 genetic multivariate calibration methods are genetic partial least squares (GPLS), genetic regression (GR), genetic classical least squares (GCLS) and genetic inverse least squares (GILS). The sample data set contains the NIR spectra of 63 ternary mixtures and covers the range from 900 to 2000 nm in 2 nm intervals. Of these 63 spectra, 42 were used as the calibration set, and 21 were reserved for the prediction purposes. Several …
Stereoselective Photochemistry Of Methoxy Chalcones In Solution And Their Radical Scavenging Activity, Nuretti̇n Yayli, Osman Üçüncü, Ahmet Yaşar, Yaşar Gök, Murat Küçük, Sevgi̇ Kolayli
Stereoselective Photochemistry Of Methoxy Chalcones In Solution And Their Radical Scavenging Activity, Nuretti̇n Yayli, Osman Üçüncü, Ahmet Yaşar, Yaşar Gök, Murat Küçük, Sevgi̇ Kolayli
Turkish Journal of Chemistry
The photochemical dimerization of 3 known methoxy derivatives of chalcones, (2E)-1-(2-methoxy)phenyl-3-phenylpropen-1-one (1), (2E)-1-(3-methoxy)phenyl-3-phenyl-propen-1-one (2), and (2E)-1-(4-methoxy) phenyl-3-phenylpropen-1-one (3), yielded 3 new \delta -truxinic type dimers in solution: rel-(1\beta ,2\alpha)- di-(2-methoxy)-benzoyl-rel-(3\beta ,4\alpha )-diphenylcyclobutane (4), rel-(1\beta ,2\alpha )-di-(3-methoxy)benzoyl-rel-(3\beta, 4\alpha )-diphenylcyclobutane (5), and rel-(1\beta ,2\alpha)- di-(4-methoxy)benzoyl-rel-(3\beta ,4\alpha )-diphenylcyclobutane (6), stereoselectively. Precursor chalcones showed high superoxide radical scavenging activity although the dimers were inactive.
Electrochemical Detection Of Specific Dna Sequences From Pcr Amplicons On Carbon And Mercury Electrodes Using Meldola's Blue As An Intercalator, Kagan Kerman, Di̇lşat Özkan, Pinar Kara, Hakan Karadeni̇z, Zeynep Özkan, Arzum Erdem, Frantisek Jelen, Mehmet Özsöz
Electrochemical Detection Of Specific Dna Sequences From Pcr Amplicons On Carbon And Mercury Electrodes Using Meldola's Blue As An Intercalator, Kagan Kerman, Di̇lşat Özkan, Pinar Kara, Hakan Karadeni̇z, Zeynep Özkan, Arzum Erdem, Frantisek Jelen, Mehmet Özsöz
Turkish Journal of Chemistry
The electrochemical parameters for 7--dimethyl--amino--1,2-- benzophenoxazinium Meldola's Blue, (MDB) on binding to DNA at both a hanging mercury drop electrode (HMDE) and carbon paste electrode (CPE) are described. MDB, which interacts with immobilized calf thymus DNA, was detected using double stranded DNA modified HMDE or CPE (dsDNA modified HMDE or CPE), bare HMDE or CPE and single stranded DNA modified HMDE or CPE (ssDNA modified HMDE or CPE) in combination with adsorptive transfer stripping voltammetry (AdTSV) techniques and decreased peak currents were observed. The discrimination of dsDNA and ssDNA and detection of hybridization between synthetic oligonucleotides were determined from changes …
Defect Structure And Properties Of Sr-Doped La Cr O_{3-\Delta}, Mahmoud Omari, Ilhem Chadli, Salah Belaidi
Defect Structure And Properties Of Sr-Doped La Cr O_{3-\Delta}, Mahmoud Omari, Ilhem Chadli, Salah Belaidi
Turkish Journal of Chemistry
A defect chemical model for the behavior of acceptor-doped LaCrO_3 as a function of oxygen pressure is proposed. This is considered within the regime that corresponds to oxygen deficit oxygen. The mathematical approach allows us to calculate the oxygen partial pressure dependant properties of La_{1-x} Sr_x Cr O_{3-\delta} in the range 0.10 \le x \le 0.30. The results show that the conductivity was independent of pO_2 and was proportional to the dopant concentration at high pO_2. Therefore, under reducing conditions, the conductivity decreased exponentially with decreasing pO_2 and asymptotically approached a pO_2^{1/4} relationship. Stability regimes and compensation mechanisms at various …
Purification And Characterization Of Pear (Pyrus Communis) Polyphenol Oxidase, Emi̇ne Zi̇yan, Şule Pekyardimci
Purification And Characterization Of Pear (Pyrus Communis) Polyphenol Oxidase, Emi̇ne Zi̇yan, Şule Pekyardimci
Turkish Journal of Chemistry
Three isoenzymes of polyphenol oxidase (PPO) were isolated from a local pear variety (Ankara Armutu) through ammonium sulfate precipitation, dialysis and gel filtration. The sample obtained from dialysis after ammonium sulfate precipitation was used for characterization of the partially purified enzyme. Optimum pH values of PPO were 8.2 for pyrogallol, 7.2 for 4-methylcatechol, 7.0 for catechol, 5.6 for D-tyrosine, 5.0 for p-cresol and 4.8 for L-dopa. The optimum temperature of PPO was 35 °C with 4-methylcatechol. Catechol was oxidized more rapidly than the other substrates; however, 4-methylcatechol, chlorogenic acid and caffeic acid were also good substrates. The effect of 6 …
Synthesis Of Novel 4-Alkylidene- And 4-Alkylamino-5-Oxo-4,5-Dihydro-[1,2,4] Triazole Derivatives And Investigation Of Their Antitumor Activities, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu
Synthesis Of Novel 4-Alkylidene- And 4-Alkylamino-5-Oxo-4,5-Dihydro-[1,2,4] Triazole Derivatives And Investigation Of Their Antitumor Activities, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu
Turkish Journal of Chemistry
A series of novel 3-alkyl-4-cyclohexylmethylenamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (6a-e) and 3-alkyl-4-hexylidenamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (7b-e) were synthesized from the reaction of corresponding 3-alkyl-4-amino-5-oxo-4,5-dihydro-[1,2,4]triazoles (1) with cyclohexancarboxaldehyde and capronaldehyde. The acetylation of compounds 6e and 7b resulted in the formation of 1-acetyl-4- cyclohexylmethylenamino-5-oxo-3-(p-tolyl)-4,5-dihydro-[1,2,4]triazole (10) and 3-benzyl-4-hexylidenamino-5-oxo-4,5-dihydro-[1,2,4]triazole (11). 3-Alkyl-4-cyclohexylmethylamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (8a-e) and 3-alkyl-4-hexylamino-5-oxo-4,5-dihydro-[1,2,4]triazoles (9b-e) were obtained from the selective reduction of compounds 6a-e and 7b-e with NaBH_4. The in vitro antitumor activity of some selected compounds was screened by the National Cancer Institute (USA) against several human tumor cell lines, and compounds 8c, 9d and 11c were found to be active.
Rapid Complexometric Determination Of Mercury(Ii) Using Glutathione As A Selective Demasking Reagent, Prakash Shetty, A. Nithyananda Shetty
Rapid Complexometric Determination Of Mercury(Ii) Using Glutathione As A Selective Demasking Reagent, Prakash Shetty, A. Nithyananda Shetty
Turkish Journal of Chemistry
A simple, rapid and selective complexometric method is proposed for the determination of mercury(II) in the presence of associated metal ions. Mercury(II) is first complexed with an excess of EDTA and the surplus EDTA is titrated against standard zinc sulphate solution at pH 5-6 using xylenol orange indicator. Glutathione is then added to displace EDTA from the Hg-EDTA complex quantitatively and the EDTA released is back titrated against a standard zinc sulphate solution as before. The method works well in the range 4 to 80 mg of mercury with a relative error of less than 0.30% and a coefficient of …
Direct Dyes Derived From 4,4'-Diaminobenzanilide Synthesis, Characterization And Toxicity Evaluation Of A Disazo Symmetric Direct Dye, Georgeta Maria Simu, Sergiu Adrian Chicu, Nicole Morin, Walter Schmidt, Eugen Şişu
Direct Dyes Derived From 4,4'-Diaminobenzanilide Synthesis, Characterization And Toxicity Evaluation Of A Disazo Symmetric Direct Dye, Georgeta Maria Simu, Sergiu Adrian Chicu, Nicole Morin, Walter Schmidt, Eugen Şişu
Turkish Journal of Chemistry
The synthesis of a new symmetric disazo direct dye containing the non--carcinogenic 4,4'-diaminobenzanilide as the middle component and salicylic acid as the coupling component is presented. The synthesized dye is an analog of the benzidine based dye C. I. Direct Yellow 1 (C. I. 22,250) and was analyzed by thin layer chromatography (TLC), electronic spectra (VIS) and mass spectroscopy (FAB-MS). The coloristic and fastness properties of the synthesized dye were determined and compared with those of C. I. Direct Yellow 1. The toxicities of the dye and of its precursors were evaluated by biological tests, using the process of metamorphosis …
Electrorheological Properties Of Suspensions Prepared From Poly(Li-Tert-Butyl Methacrylate) Ionomer, Mustafa Yavuz, Hali̇l İbrahi̇m Ünal
Electrorheological Properties Of Suspensions Prepared From Poly(Li-Tert-Butyl Methacrylate) Ionomer, Mustafa Yavuz, Hali̇l İbrahi̇m Ünal
Turkish Journal of Chemistry
The synthesis, characterisation and partial hydrolysis of poly(tert-butylmethacrylate), (PTBMA), and the electrorheological (ER) properties of its suspensions were investigated. The polymer was synthesised by radical polymerisation and partially hydrolysed by para-toluenesulphonic acid monohydrate (PTSA.H_2O), and then converted to a lithium salt (PTBMA-Li) by washing with a LiOH_{(aq)} solution. From particle size measurements, the average particle size of PTBMA-Li was determined to be 74 \mu m. Colloidal suspensions of ionomer were prepared in various insulating oils [silicone oil (SO), mineral oil (MO), threeoctylthreemellitate (TOTM) and dioctylphatalete (DOP)] at a series of concentrations (c = 5-33 m/m, %). The sedimentation stabilities of …
Study On The Solid Phase Extraction And Spectrophotometric Determination Of Cobalt With 2-(2-Quinolylazo)-5-Diethylaminoaniline, Qiufen Hu, Guangyu Yang, Xuechang Dong, Jiayuan Yin
Study On The Solid Phase Extraction And Spectrophotometric Determination Of Cobalt With 2-(2-Quinolylazo)-5-Diethylaminoaniline, Qiufen Hu, Guangyu Yang, Xuechang Dong, Jiayuan Yin
Turkish Journal of Chemistry
A sensitive, selective and rapid method for the determination of cobalt based on the rapid reaction of cobalt(II) with QADEAA and the solid phase extraction of the Co(II)-QADEAA chelate with C_{18} membrane disks was developed. In the presence of pH = 5.5 buffer solution and cetyl trimethylammonium bromide (CTMAB) medium, QADEAA reacts with cobalt to form a violet complex with a molar ratio of 1:2 (cobalt to QADEAA). This chelate was enriched by the solid phase extraction with C_{18} membrane disks. An enrichment factor of 50 was obtained by elution of the chelate from the disks with a minimal amount …
Neolignan And Phenylethanoid Glycosides From Verbascum Salviifolium Boiss, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan
Neolignan And Phenylethanoid Glycosides From Verbascum Salviifolium Boiss, Zeli̇ha Ş. Akdemi̇r, İ. İrem Tatli, Erdal Bedi̇r, Ikhlas A. Khan
Turkish Journal of Chemistry
From the aerial parts of Verbascum salviifolium Boiss., 2 neolignan glucosides, dehydrodiconiferyl alcohol-9'-O-\beta -D-glucopyranoside (1) and dehydrodiconiferyl alcohol-9-O-\beta- D-glucopyranoside (2), along with 5 phenylethanoid glycosides, acteoside (= verbascoside) (3), \beta -hydroxyacteoside (4), forsythoside B (5), angoroside A (6) and martynoside (7), were isolated. The structure elucidation of the isolated compounds was established on the basis of spectroscopic evidence. Compounds 1-7 demonstrated scavenging properties toward the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in TLC autographic and spectroscopic assays.
Preparation, Spectroscopic Studies And Biological Activity Of Mono-Organotin(Iv) Derivatives Of Non-Steroidal Anti-Inflammatory Drugs, Azra Jalal, Saira Shahzadi, Khadiji Shahid, Saqib Ali, Amin Badshah, Mohammad Mazhar, Khalid Mohammed Khan
Preparation, Spectroscopic Studies And Biological Activity Of Mono-Organotin(Iv) Derivatives Of Non-Steroidal Anti-Inflammatory Drugs, Azra Jalal, Saira Shahzadi, Khadiji Shahid, Saqib Ali, Amin Badshah, Mohammad Mazhar, Khalid Mohammed Khan
Turkish Journal of Chemistry
A set of 14 mono-organotin(IV) derivatives of general formulae n-BuSnClL_2 and n-BuSnL_3, where `L' are various non-steroidal anti-inflammatory drugs (NSAIDs), were synthesized and structurally characterized by vibrational, ^1H, ^{13}C and ^{119}Sn spectroscopies and mass spectrometry to propose their structure. Biological activity data (antibacterial, antifungal and cytotoxicity) of the synthesized complexes were compared with the precursors to establish the significance of the complexes.
Synthesis And Characterization Of Block Copolymers Using Polysiloxane Based Macroazoinitiator, Sennur Deni̇z, Ni̇l Baran, Mesut Akgün, Nalan A. Akgün, Sali̇h Di̇nçer
Synthesis And Characterization Of Block Copolymers Using Polysiloxane Based Macroazoinitiator, Sennur Deni̇z, Ni̇l Baran, Mesut Akgün, Nalan A. Akgün, Sali̇h Di̇nçer
Turkish Journal of Chemistry
Poly(dimethylsiloxane-b-styrene) (PDMS-b-PSt) and poly(dimethylsiloxane-b-methyl methacrylate) (PDMS-b-PMMA) block copolymers containing siloxane segments were studied by the radical polymerizations of vinyl monomers such as styrene (St) and methyl methacrylate (MMA) using polydimethylsiloxane based macroazoinitiator (PDM-MAI) in solution. PDM-MAI was synthesized by reacting hydroxy-terminated polydimethylsiloxane (PDMS) and 4,4'-azobis (4-cyanopentanoyl chloride) (ACPC) having a thermodegradable azo-linkage. The polycondensation reaction between PDMS and ACPC (2:1, molar ratio) was carried out at room temperature. The polymerizations of St and MMA initiated by PDM-MAI were investigated using different PDM-MAI concentrations (1, 5, 10, and 15 wt. %) for various reaction times with a methyl ethyl ketone (MEK)/ …
The Crystal And Molecular Structure Of 1-(2-Chloro-Benzoyl)-3-P-Tolyl-Thiourea, Hakan Arslan, Ulrich Flörke, Nevzat Külcü
The Crystal And Molecular Structure Of 1-(2-Chloro-Benzoyl)-3-P-Tolyl-Thiourea, Hakan Arslan, Ulrich Flörke, Nevzat Külcü
Turkish Journal of Chemistry
1-(2-Chloro-benzoyl)-3-p-tolyl-thiourea was synthesized and characterized by elemental analysis and IR spectroscopy. The crystal and molecular structure of the title compound was determined from single-crystal X-ray diffraction data. It crystalizes in the triclinic space group P-1, with a = 7.9942(9) Å, b = 9.531(1) Å, c = 11.075(1) Å, \alpha = 97.235(2) °, \beta = 111.099(2) °, and \gamma = 106.105(2) °.
Synthesis And Antitumor Activities Of Some New 4-(1-Naphthylidenamino)- And 4-(1-Naphthylmethylamino)-1,2,4-Triazol-5-One Derivatives, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu
Synthesis And Antitumor Activities Of Some New 4-(1-Naphthylidenamino)- And 4-(1-Naphthylmethylamino)-1,2,4-Triazol-5-One Derivatives, Nesli̇han Demi̇rbaş, Reyhan Uğurluoğlu
Turkish Journal of Chemistry
A series of 4-(1-naphthylidenamino)-1,2,4-triazol-5-one derivatives (3a-e) were synthesized by condensation of corresponding 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones with 1-naphthaldehyde. Acetylation and alkylation of these compounds gave 4a-e and 5a-e, respectively. Sodium borohydride reduction of 1-naphthylidenamino derivatives afforded naphthylmethylamino derivatives, which were subsequently acetylated. Depending on the duration of the acetylation, mono or bis acetamide derivatives were obtained. The in vitro antitumor activities of some selected compounds were screened and compounds 3e, 5c, 6e and 9c} were found to be active.
Synthesis, Spectral And Thermal Properties Of Some Penta-Coordinated Complexes Of Oxovanadium(Iv) Derived From Thiosemicarbazones Of 4-Aminoantipyrine, Ram K. Agarwal, Surendra Prasad, Neetu Gahlot
Synthesis, Spectral And Thermal Properties Of Some Penta-Coordinated Complexes Of Oxovanadium(Iv) Derived From Thiosemicarbazones Of 4-Aminoantipyrine, Ram K. Agarwal, Surendra Prasad, Neetu Gahlot
Turkish Journal of Chemistry
The paper reports the synthesis of crystalline oxovanadium(IV), VO^{2+}, complexes of thiosemicarbazones, i.e. 4[N-(4'-nitrobenzalidene)amino]antipyrine thiosemicarbazone (4'-NO_2BAAPTS) and 4[N-(furan-2'-aldimine)amino]antipyrine thiosemicarbazone (FFAAPTS) with general composition VOX_2L (X = Cl, Br, I, NO_3 or NCS) and VO(ClO_4)_2(L)H_2O (L = 4'-NO_2BAAPTS or FFAAPTS). All the complexes were characterized by elemental analyses, molar mass, molar conductance, magnetic susceptibility, infrared and electronic spectra. In all the complexes, both the thiosemicarbazones behave as neutral tridentate (N, N, S) ligands. The thermal properties of the representative complexes are also reported. The most probable geometry of the complexes is proposed.
An Atropisomeric Chiral 2,2'-Bipyridyl-3,3'-Dicarboxylic Acid And Corresponding Platinum(Ii) Complex, Abdurrahman Şengül
An Atropisomeric Chiral 2,2'-Bipyridyl-3,3'-Dicarboxylic Acid And Corresponding Platinum(Ii) Complex, Abdurrahman Şengül
Turkish Journal of Chemistry
2,2'-Bipyridyl-3,3'-dicarboxylic acid (H_2BDC) spontaneously resolves on crystallization from water, giving monohydrated crystals of the space group P2_12_12_1. In any individual crystal, all the atropisomeric-skewed molecules are of one hand; however, on dissolution in water, optical activity is lost. Strong hydrogen bonding leads to a helical structure, via O--H ... N links, and 3 further strong bonds between water and carboxylate groups produce a framework structure. The pK_a values measured for H_2BDC (3.18 \pm 0.04 and 4.59 \pm 0.02 at 20 \pm 1 °C, in dilute aqueous solution) agree with the zwitterionic form. The reaction of H_2BDC with potassium tetrachloroplatinate(II) in …
Bromination Of Tricyclo[7.2.1.0^{2,7}]Dodeca-2,4,6,10-Tetraene Derivatives: Electronic And Neighboring Group Effects On Bromination, Ari̇f Daştan
Turkish Journal of Chemistry
The bromination reaction of tricyclo[7.2.1.0^{2,7}]dodeca-2,4,6,10-tetraene derivatives was studied. The bromination of 9 gave only rearranged products 12 and 13, while the bromination of 8 with molecular bromine formed both rearranged 12 and non-rearranged products 15 and 16. The possible role of a substituent in the rearrangements was examined. All compounds were characterized properly, in particular by NMR spectra and chemical transformation.
X-Ray Diffraction Study Of The Changes Induced During The Thermal Degradation Of Poly (Methyl Methacrylate) And Poly (Methacryloyl Chloride), Rizwan Hussain, Din Mohammad
X-Ray Diffraction Study Of The Changes Induced During The Thermal Degradation Of Poly (Methyl Methacrylate) And Poly (Methacryloyl Chloride), Rizwan Hussain, Din Mohammad
Turkish Journal of Chemistry
Poly (methyl methacrylate) -- PMMA -- and poly (methacryloyl chloride) -- PMACl -- were synthesized by free radical solution polymerization. The thermal stabilities of these polymers were determined with the help of thermogravimetry and differential thermal analysis. The structural changes in these materials at different temperatures (90, 140, 220 and 410 °C) were studied by X-ray diffraction. These studies indicate that PMACl is less amorphous than PMMA due to the presence of bulky chloride groups
Phenylpropanoid Glycosides From Linum Olympicum (Linaceae), Belma Konuklugi̇l, Özlem Bahadir
Phenylpropanoid Glycosides From Linum Olympicum (Linaceae), Belma Konuklugi̇l, Özlem Bahadir
Turkish Journal of Chemistry
The lignan content of Linum olympicum Boiss. was investigated by HPLC and GC-MS in comparison with standards, and 2 phenylpropanoid glycosides, syringin (1) and coniferin (2), were isolated from the aerial parts. Identification of the 2 compounds was achieved by comparison with standards using TLC and HPLC and the structures of the isolated compounds were established by UV and ^1H-NMR analysis.
Acylated Flavone Glycosides From Veronica Pectinata Var. Glandulosa And V. Persica, İclal Saracoğlu, Ü. Şebnem Harput, Yukio Ogihara
Acylated Flavone Glycosides From Veronica Pectinata Var. Glandulosa And V. Persica, İclal Saracoğlu, Ü. Şebnem Harput, Yukio Ogihara
Turkish Journal of Chemistry
This study deals with the isolation of a new acylated 5,6,7,3',4'-pentahydroxy-flavone glycoside (1) and 3 known allose-containing acylated flavone glycosides (2-4) as well as a known flavone aglycone (5) from the aerial parts of Veronica pectinata var. glandulosa and V. persica. The structures of the isolated compounds were determined to be 3' -hydroxy-4'-O-methylscutellarein-7-O-[2''-O-\alpha -L-rhamnopyranosyl-3''-O-(6''''-O-acetyl-\beta -D-glucopyranosyl)]-\beta- D-glucopyranoside, named sarachoside (1), 4' -O-methylisoscutellarein-7-O-2''- O-(6''' -O-acetyl-\beta -D-allopyranosyl)-\beta -D-glucopyranoside (2), isos\-cutellarein-7-O-2''-O-(6'''-O-acetyl-\beta-D-allopyranosyl)-\beta- D-glucopyranoside (3), 3'-hydroxy-4'-O-methy\-lisoscutellarein-7-O-2'' -O-(6'''-O-acetyl-\beta -D-allopyranosyl)-\beta -D-glucopyranoside (4) and 5,4'-dihydroxy-6,7,3' -trimethoxyflavone, named circilineol (5) by extensive 1-D and 2D-NMR spectroscopy. Sarachoside (1) exhibited potent radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.
Methoxyflavonoids From Pinaropappus Roseus, Ü. Şebnem Harput, İclal Saracoğlu, Yukio Ogihara
Methoxyflavonoids From Pinaropappus Roseus, Ü. Şebnem Harput, İclal Saracoğlu, Yukio Ogihara
Turkish Journal of Chemistry
Three rare methoxyflavonoids, rhamnazin 3-O-rutinoside (1), rhamnocitrin 3-O-rutinoside (2) and isorhamnetin 3-O-rutinoside (3), were isolated from the methanolic extract of Pinaropappus roseus together with 2 well-known flavonoids, quercetin 3-O-rutinoside (=rutin) (4) and kaempferol 3-O-rutinoside (5). The structures of the isolated compounds were elucidated on the basis of UV, 1D and 2D NMR and FAB-Mass spectral analysis. Free radical scavenging activities of the isolated compounds were also demonstrated. This is the first report on the chemical composition of the genus Pinaropappus.
Secondary Metabolites From Phlomis Kotschyana, Ü. Şebnem Harput, İclal Saracoğlu, İhsan Çaliş, Ali̇ Arslan Dönmez, Akito Nagatsu
Secondary Metabolites From Phlomis Kotschyana, Ü. Şebnem Harput, İclal Saracoğlu, İhsan Çaliş, Ali̇ Arslan Dönmez, Akito Nagatsu
Turkish Journal of Chemistry
A lignan glycoside, syringaresinol-4',4''-O-di-\beta -D-glucopyranoside (1) (=liriodendrin), 4 phenylethanoid glycosides, acteoside (2), isoacteoside (3), forsythoside B (4) and leucosceptoside B (5), a caffeic acid ester, chlorogenic acid (6) and 2 iridoid glucosides, lamiide (7) and auroside (8), were isolated from the methanolic extracts of the aerial parts of Phlomis kotschyana along with an acetophenone glycoside, 4-hydroxyacetophenone 4-O-[6'-O-\beta -D-apiofuranosyl]-\beta -D-glucopyranoside (9). The structures of the isolated compounds were identified on the basis of spectroscopic (UV, IR, 1D- and 2D-NMR, and FAB-MS) methods.
Synthesis And Reactivity Of Tetrahydroimidazo [1,5-B][1,2,4]Oxadiazol- 2(1h)-Thiones, Necdet Coşkun, Fatma Ti̇rli̇ Tat
Synthesis And Reactivity Of Tetrahydroimidazo [1,5-B][1,2,4]Oxadiazol- 2(1h)-Thiones, Necdet Coşkun, Fatma Ti̇rli̇ Tat
Turkish Journal of Chemistry
1,3-Dipolar cycloaddition of imidazoline 3-oxides 1 with methylisothiocyanate proceeds regio- and diastereoselectively to give tetrahydroimidazo[1,5-b][1,2,4]oxadiazol-2(1H)-thiones 3 in high yields. The cis configuration of the adducts was proved by our double cis elimination test as well as by NOESY experiments. Adducts 3a-c undergo ring opening at reflux in acetonitrile to give imidazoles while 3d-e undergo retro dipolar cycloaddition to give the starting nitrones 1d-e. The imidazooxadiazol-2-thiones 3a-e were treated with concentrated HCl in ethanol at 50 °C to give the corresponding 4H-[1,2,4]oxadiazole-5-thione only in cases in which the substituent at C-6 is an aryl.
New Adsorbents From Ti(Opr^{N})_{4} By The Sol-Gel Process: Synthesis, Characterization And Application For Removing Some Heavy Metal Ions From Aqueous Solution, Funda Sayilkan, Hi̇kmet Sayilkan, Sema Erdemoğlu, Şadi̇ye Şener, Murat Akarsu
New Adsorbents From Ti(Opr^{N})_{4} By The Sol-Gel Process: Synthesis, Characterization And Application For Removing Some Heavy Metal Ions From Aqueous Solution, Funda Sayilkan, Hi̇kmet Sayilkan, Sema Erdemoğlu, Şadi̇ye Şener, Murat Akarsu
Turkish Journal of Chemistry
New adsorbents were synthesized by the sol-gel process from the product of a hydrolysis reaction and its coated form of titanium(IV)-n-propoxide for removing some heavy metal ions from aqueous solution. Titanium(IV)-n-propoxide was uncatalyst hydrolyzed with different amounts of water at room temperature and was found to react in a 1:1.6 ratio (mole of Ti:mole of H_{2}O). It was found that the condensation following the hydrolysis reaction was alcohol condensation. The hydrolysis-condensation product was characterized in detail by GC, Karl-Fischer coulometric titrator, NIR-spectroscopy, FT-IR spectroscopy, TG-DTA and elemental analysis. The hydrolysis-condensation product of titanium(IV)-n-propoxide was calcinated at 900 °C after drying …
Synthesis And Antimicrobial Activity Of Some Pyridyl And Naphthyl Substituted 1,2,4-Triazole And 1,3,4-Thiadiazole Derivatives, Khosrow Zamani, Khalil Faghihi, Taraneh Tofighi, Mohammad Reza Shariatzadeh
Synthesis And Antimicrobial Activity Of Some Pyridyl And Naphthyl Substituted 1,2,4-Triazole And 1,3,4-Thiadiazole Derivatives, Khosrow Zamani, Khalil Faghihi, Taraneh Tofighi, Mohammad Reza Shariatzadeh
Turkish Journal of Chemistry
Synthesis of new 1,2,4-tri and 1,3,4-thiadiazoles, bearing isomeric pyridyl and 1-naphthyl is reported using 1,4-disubstituted thiosemicarbazides in alkaline and acidic media, respectively. The methylthio and benzylthio derivatives of the synthesized triazoles are also reported. All of the synthesized compounds were characterized by their FT-IR, ^{1}H-NMR and mass spectral data. The antibacterial studies of some of the synthesized compounds against S. aureus} and E. coli} as MIC values are reported. None of them have important antibacterial activities.