Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- 1 (6)
- Synthesis (5)
- 2 (4)
- Antibacterial activity (3)
- Cyclic voltammetry (3)
-
- Phthalocyanine (3)
- 3 (2)
- Activated carbon (2)
- Adsorption (2)
- Antioxidant activity (2)
- Antitumor activity (2)
- Benzimidazole (2)
- Benzotriazole (2)
- Bioanode (2)
- Bioconcentration (2)
- CH$_{4}$ adsorption (2)
- Catalysis (2)
- Characterization (2)
- Coumarin (2)
- Differential pulse voltammetry (2)
- Enzyme immobilization (2)
- Flavonoids (2)
- Glucose oxidase (2)
- Graphene oxide (2)
- Green chemistry (2)
- HPLC (2)
- High-performance liquid chromatography (2)
- Hydroxyapatite (2)
- Intercalation (2)
- Ionic liquid (2)
Articles 121 - 134 of 134
Full-Text Articles in Physical Sciences and Mathematics
Amperometric Urea Biosensor Based On Immobilized Urease On Polypyrrole And Macroporous Polypyrrole Modified Pt Electrode, Maliheh Hosseinian, Ghasem Najafpour, Ahmad Rahimpour
Amperometric Urea Biosensor Based On Immobilized Urease On Polypyrrole And Macroporous Polypyrrole Modified Pt Electrode, Maliheh Hosseinian, Ghasem Najafpour, Ahmad Rahimpour
Turkish Journal of Chemistry
Biosensing of urea by a biosensor as a direct detection method at ambient temperature and pressure instead of chromatography leads to a significant reduction in processing costs. Amperometric biosensors based on urease immobilization on macroporous polypyrrole (MPPy) and pyrrole on the surface of a Pt electrode were developed. Applying cyclic voltammetry (CV), we demonstrated the synthesis of MPPy using monodispersed polystyrene spheres (460 nm) as a template. CV and chronoamperometric studies were conducted to evaluate the electrochemical current of the modified electrodes. For the electrode with polypyrrole (PPy), the biosensor response was linear in the range of 1.67--8.32 mM (R$^{2}$ …
A Novel Silver(I)-Selective Pvc Membrane Sensor And Its Potentiometric Applications, Ömer Işildak, Ni̇hal Deli̇gönül, Oğuz Özbek
A Novel Silver(I)-Selective Pvc Membrane Sensor And Its Potentiometric Applications, Ömer Işildak, Ni̇hal Deli̇gönül, Oğuz Özbek
Turkish Journal of Chemistry
Silver(I)-selective sensors were prepared from a solid-state contact polyvinyl chloride (PVC) membrane. ($Z)$-2-(2-((3-(2-hydroxyphenyl)-5-(p-tolyl)-1$H$-pyrrol-2-yl)imino)-5-(p-tolyl)-2$H$-pyrrol-3-yl)phenol was synthesized as an ionophore molecule and embedded in the silver(I)-selective PVC membrane composition. The optimum membrane composition was determined as 2.5% ionophore, 61.7% bis-(2-ethylhexyl)sebacate, 1.0% potassium tetrakis (p-chlorophenyl) borate, and 34.8% PVC. The developed sensor exhibited a linear potential change $E$ = 67.42 (-log [Ag$^{+}$]) $+$ 1152.9 and $R^{2}$ = 0.9960) in the varying concentration range of 1.0 $\times $ 10$^{-1}$ to 1.0 $\times $ 10$^{-5}$ mol L$^{-1}$ silver ions. This sensor shows a detection limit of 7.3 $\times $ 10$^{-7}$ mol L$^{-1}$. The proposed sensor …
Acetyl- And Butyrylcholinesterase Inhibitory Activity Of Selected Photochemically Synthesized Polycycles, Ivana Sagud, Irena Skoric, Dragana Vuk, Ana Ratkovic, Franko Burcul
Acetyl- And Butyrylcholinesterase Inhibitory Activity Of Selected Photochemically Synthesized Polycycles, Ivana Sagud, Irena Skoric, Dragana Vuk, Ana Ratkovic, Franko Burcul
Turkish Journal of Chemistry
Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the main cause of dementia in the elderly population. Since the treatment of AD has been associated with the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), their inhibitors remain the main focus of AD investigations. In this study we evaluated cholinesterase inhibitory activity of 14 bicyclo[3.2.1]octene/octadiene derivatives and naturally occurring sesquiterpene alcohol cedrol. These 14 compounds have been efficiently and ecologically prepared by a photochemical approach in batch photochemical reactors. Various compounds with the bicyclo[3.2.1]octene skeleton have already been successfully evaluated for treatment of central nervous system disorders and AD. Among …
Amino-Functionalized Mesostructured Cellular Foam Silica: A Highly Efficient And Recyclable Catalyst In The Knoevenagel Condensation Reaction, Dong Hao, Hongyuan Yang, Tengfei Zhang, Qing Liu
Amino-Functionalized Mesostructured Cellular Foam Silica: A Highly Efficient And Recyclable Catalyst In The Knoevenagel Condensation Reaction, Dong Hao, Hongyuan Yang, Tengfei Zhang, Qing Liu
Turkish Journal of Chemistry
Mesostructured cellular foam silica was functionalized by an amino group (MCF-NH$_{2})$ using the postsynthesis grafting method and utilized as a recyclable catalyst for the Knoevenagel reaction to afford $\alpha $, $\beta $-unsaturated compounds. The catalyst was systematically characterized by various analyses such as nitrogen adsorption, X-ray diffraction, Fourier transform infrared spectrophotometry, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and Hammett indicator method. The results showed that MCF-NH$_{2}$ catalyst was successfully prepared with a high surface area of 215 m$^{2}$ g$^{-1}$ and a large pore volume of 1.37 cm$^{3}$ g$^{-1}$. Compared with the nonfunctionalized MCF sample, the window and cell …
Magnetic Solid-Phase Extraction Based On Coriolus Versicolor-Immobilized $\Gamma $-Fe$_{2}$O$_{3}$ Nanoparticles For Preconcentration And Determination Of Al(Iii) In Water And Food Samples, Sadi̇n Özdemi̇r, Mustafa Serkan Yalçin, Ersi̇n Kilinç, Mustafa Soylak
Magnetic Solid-Phase Extraction Based On Coriolus Versicolor-Immobilized $\Gamma $-Fe$_{2}$O$_{3}$ Nanoparticles For Preconcentration And Determination Of Al(Iii) In Water And Food Samples, Sadi̇n Özdemi̇r, Mustafa Serkan Yalçin, Ersi̇n Kilinç, Mustafa Soylak
Turkish Journal of Chemistry
A method for preconcentration of Al(III) prior to its determination by inductively coupled plasma-optical emission spectrometry (ICP-OES) was developed because the sensitivity of ICP-OES is insufficient for trace-level measurement of Al(III). The method is based on the use of Coriolus versicolor}-immobilized $\gamma $-Fe$_{2}$O$_{3}$ magnetic nanoparticles as a solid phase sorbent. The best experimental conditions were found as pH 6.0, 2.0 mL/min flow rate, 100 mg amount of C. versicoloron 150 mg of $\gamma $-Fe$_{2}$O$_{3}$ nanoparticles, and 500 mL of sample volume. The Al(III) absorbed on biosorbent was eluted with 5.0 mL of 1.0 mol/L HCl. Limit of detection, limit of …
Design, Synthesis, Biological Evaluation And Molecular Docking Of Novel Molecules To Parp-1 Enzyme, Fati̇h Tok, Bedi̇a Kaymakçioğlu, Recep İlhan, Si̇nem Yilmaz, Petek Ballar Kirmizibayrak, Tuğba Taşkin Tok
Design, Synthesis, Biological Evaluation And Molecular Docking Of Novel Molecules To Parp-1 Enzyme, Fati̇h Tok, Bedi̇a Kaymakçioğlu, Recep İlhan, Si̇nem Yilmaz, Petek Ballar Kirmizibayrak, Tuğba Taşkin Tok
Turkish Journal of Chemistry
Poly (ADP-ribose) polymerase (PARP) enzyme catalyzes the transfer of ADP-ribose into target proteins. Therefore, PARP is responsible for DNA repair, cell proliferation, and cell death. In this study, potential PARP enzyme inhibitors were designed and synthesized. The synthesized compounds were elucidated by Fourier-transform infrared spectroscopy, $^{1}$H NMR, $^{13}$C NMR, heteronuclear single-quantum correlation, and mass spectrometry, and their purity was checked via thin-layer chromatography, high-performance liquid chromatography, and elemental analysis. A total of 63 newly synthesized compounds were screened in terms of PARP inhibition by cellular PARylation assay in the HeLa cell line. It was found that 19 compounds significantly inhibited …
In Silico And In Vitro Evaluation Of The Biological Activity Of Some Organic Sulfur-Containing Compounds, Victoria Osipova, Maria Polovinkina, Anastasia Osipova, Yulia Gracheva, Andrey Okhlobystin
In Silico And In Vitro Evaluation Of The Biological Activity Of Some Organic Sulfur-Containing Compounds, Victoria Osipova, Maria Polovinkina, Anastasia Osipova, Yulia Gracheva, Andrey Okhlobystin
Turkish Journal of Chemistry
It was predicted, using the Prediction of Activity Spectra for Substances online software, that organic sulfur-containing compounds 2,6-di-tert-butyl-4-mercaptophenol (1), 2,6-di-tert-butyl-4-(3-mercaptopropyl)phenol (2), bis-3-[3,5-di-tert-butyl-4-hydroxyphenyl)propyl] sulfide (3), bis(3,5-di-tert- butyl-4-hydroxyphenyl) disulfide (4), diphenyl disulfide (5), dibenzyl disulfide (6), dibutyl disulfide (7), di-tert-butyl disulfide (8), diallyl disulfide (9), and methyl propyl trisulfide (10) could possess antioxidant activity and act as active scavengers of oxygen metabolites. The antiradical activity of these species was analyzed and it was shown that they were able to react with electrochemically generated the superoxide anion radical. The rate constants for reactions of 1-10 with the superoxide anion radical were calculated. The …
Electrochemical Responses Of Flexible Graphite In H$_2$So$_4$, Mehmet Suha Yazici
Electrochemical Responses Of Flexible Graphite In H$_2$So$_4$, Mehmet Suha Yazici
Turkish Journal of Chemistry
Asymmetric capacitors are gaining attention due to their hybrid nature with higher power and energy density compared to individual batteries or capacitors. Electrochemical and structural characteristics of flexible graphite in 40% H$_{2}$SO$_{4\, }$electrolyte are investigated using electrochemical and microscopy techniques. There is a correlation between intercalation of electrolyte and the enlargement of interlayer spacing and electrochemical response. Conditions favoring planar orientation are electrochemically less active and more stable in such corrosive electrolytes. There are response variations between plain and resin-impregnated flexible graphite samples. The reaction peak seems to be reversible for resin impregnated samples while plain samples show continuous intercalation. …
Acetylene-Bridged Triazine Π-Conjugated Structures: Synthesis And Liquid Crystalline Properties, Ni̇hat Akkurt, Mohammed Hadi Ali Al-Jumaili, Belkiz Bi̇lgi̇n Eran, Hale Ocak, Lokman Torun
Acetylene-Bridged Triazine Π-Conjugated Structures: Synthesis And Liquid Crystalline Properties, Ni̇hat Akkurt, Mohammed Hadi Ali Al-Jumaili, Belkiz Bi̇lgi̇n Eran, Hale Ocak, Lokman Torun
Turkish Journal of Chemistry
We report the synthesis and liquid crystalline properties of a new type of tribranched compound built up from triazine as the central core and electron-rich triazine rings as peripheral groups. An equimolar mixture of the star-shaped compound based on the 1,3,5-triazine core with 4-dodecyloxybenzoic acid produced an organic salt exhibiting a columnar mesophase with a dendritic growing texture at low temperatures. The liquid crystalline properties of the triazine-based compound and organic salt were investigated by differential scanning calorimetry and polarizing optical microscopy.
The Solvatochromism And Electronic Structure Of (E)-2-(2-Hydroxystyryl)Quinolin-8-Ol, Ayşegül Gümüş, Yadi̇gar Gülseven Sidir, İsa Sidir, Selçuk Gümüş
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, …
Stability Improvement By Crosslinking Of Previously Immobilized Glucose Oxidase On Carbon Nanotube-Based Bioanode, Tahsi̇n Bahar
Stability Improvement By Crosslinking Of Previously Immobilized Glucose Oxidase On Carbon Nanotube-Based Bioanode, Tahsi̇n Bahar
Turkish Journal of Chemistry
Bioanode stability with glucose oxidase was enhanced significantly by covalent crosslinking without substantial enzymatic activity and affinity loss. Initially, glucose oxidase was immobilized by aldehyde groups on the electrode that was developed using ferrocenecarboxaldehyde, polyethyleneimine, multiwall carbon nanotubes, and carbon cloth for biofuel cell applications. The glucose oxidase half-life was extended by more than 4 times, from 27.2 to 124.7 h, after the electrode was crosslinked. Enzymatic kinetic parameters were determined for the crosslinked enzyme and they were compared to the noncrosslinked immobilized enzyme parameters on the electrode. The apparent substrate affinity of the crosslinked enzyme electrode was decreased (i.e. …
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
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 …
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
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.
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
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 …