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Analytical approaches for clarification of DNA-double decker phthalocyanine binding mechanism: As an alternative anticancer chemotherapeutic
(PERGAMON-ELSEVIER SCIENCE LTD, 2017) Bagda, Esra; Yabas, Ebru; Bagda, Efican
In the present study a novel water soluble double-decker phthalocyanine was synthesized and calf thymus DNA interaction of the synthesized double-decker phthalocyanine was investigated. 5-(3-pyridyl)-1,3,4-oxadiazole substituted phthalonitrile 1 was prepared by a nucleophilic displacement reaction of 4-nitrophthalonitrile with 5-(3-pyridyl)-1,3,4-oxadiazole-2-thiol. Lutetium(III) double-decker phthalocyanine 2 was prepared by cyclotetramerization of compound 1. Water soluble lutetium(III) double-decker phthalocyanine 3 was prepared with quaternarization of compound 2. The synthesized double-decker phthalocyanine and calf thymus DNA interaction was investigated with UV-vis titrimetric methods, gel electrophoresis, and viscosity measurements. The fluorometric ethidium bromide replacement assay was conducted to clarify the binding mode of water soluble double-decker phthalocyanine. The thermodynamic parameters for interaction, K, Delta G(0), Delta H-0 and Delta S-0 were calculated between the temperature ranges of 25 degrees C-75 degrees C. To the best of our knowledge, this is the first study about a double-decker phthalocyanine and DNA interaction. (C) 2016 Published by Elsevier B.V.
Antioxidant activities of the new tetrasubstituted metal-free, Zn(II) and Co(II) monophthalocyanines
(WORLD SCI PUBL CO INC, 2018) Soylemez, Nazli; Yabas, Ebru; Bolukbasi, Serap Sahin; Sulu, Mustafa
4-[(4'-(Tert-butyl) phenoxy) phenoxy] phthalonitrile 1 has been prepared by the reaction of 4-(4-nitrophenoxy) phthalonitrile with 4-tertiarylbutylphenole. 4-((4'-tert-butyl) phenoxy) phenoxy tetrasubstituted metal-free 2, zinc(II) 3 and cobalt(II) 4 phthalocyanines have been prepared by tetramerization of compound 1. The synthesized phthalocyanines showed high solubility in common organic solvents such as CHCl3. All compounds were characterized by elemental analysis and H-1-NMR, C-13-NMR, UV-vis, IR spectra. Aggregation behaviors of these compounds have been investigated in different solvents (CHCl3, THF, DMF and DMSO) and different concentrations in CHCl3. The in vitro antioxidant activities of phthalocyanine compounds 2, 3 and 4 were evaluated in a series of assays involving DPPH radicals, hydroxyl radicals, superoxide radicals, singlet oxygen and hydrogen peroxide. Antioxidant activity of compound 2 was found to be higher than that of compounds 3 and 4.
Circular dichroism spectroscopic investigation of double-decker phthalocyanine with G-Quadruplex as promising telomerase inhibitor
(ELSEVIER SCIENCE BV, 2017) Bagda, Efkan; Bagda, Esra; Yabas, Ebru
In the present study, interaction of a double-decker phthalocyanine with two G-quadruplex DNA, Tel 21 and cMYC, was investigated. To the best of our knowledge, this is the first study about G-quadruplex-double decker phthalocyanine interaction. The spectrophotometric titration method was used for binding constant calculations. From the binding constants, it can be said that double-decker phthalocyanine more likely to bind Tel 21 rather than cMYC. The conformational changes upon binding were monitored via circular dichroism spectroscopy. The ethidium bromide replacement assay was investigated spectrofluorometrically. (C) 2016 Published by Elsevier B.V.
Electrical and electrochemical properties of double-decker Lu(III) and Eu(III) phthalocyanines with four imidazoles and N-alkylated imidazoles
(PERGAMON-ELSEVIER SCIENCE LTD, 2012) Yabas, Ebru; Sulu, Mustafa; Dumludag, Fatih; Ozkaya, Ali Riza; Salih, Bekir; Bekaroglu, Ozer
Imidazole tetrasubstituted double-decker Lu(III) (2) and Eu(III) (3) phthalocyanines have been synthesized by heating 4[(4,5-diphenyl-1H-imidazole)-2-yl-thio]phthalonitrile (1) with Lu(OAc)(3)center dot nH(2)O or Eu(OAc)(3)center dot nH(2)O in n-hexanol in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, respectively. N-alkylated imidazole tetrasubstituted double-decker Lu(III) (4) and Eu(III) (5) phthalocyanines have been synthesized by the reaction of compounds 2 and 3 with hexyl bromide, in DMF in the presence of K2CO3, respectively. The new compounds were obtained in sufficient purity after successive washing with different solvents and were characterized by elemental analysis and H-1 NMR, UV-Vis, IR, MALDI-TOF mass and electron spin resonance spectra. Electrical measurements of the 2-5 performed in a vacuum (<2 x 10(-3) mbar) in the dark between the temperatures of 295 and 523 K suggest that their films show semi-conductor behavior. It was found that, in general, sigma(d.c.) (4) > sigma(d.c.) (2) in the temperature range 295-458 K, and sigma(d.c). (5) > sigma(d.c.) (3) in the measured temperature range. Depressed semi-circles with different radii at high temperatures in impedance spectra measurements indicated deviation from the Debye dispersion relation. The redox behaviors of the compounds were also investigated by voltammetry and in situ spectroelectrochemistry in dimethylsulfoxide with tetrabutylammonium perchlorate. (c) 2012 Elsevier Ltd. All rights reserved.
Feasibility of tetracycline, a common antibiotic, as chelating agent for spectrophotometric determination of UO22+ after cloud point extraction
(SPRINGER, 2014) Bagda, Esra; Yabas, Ebru; Karakus, Nihat
A cloud point extraction (CPE) procedure was presented for the preconcentration of UO22+ ion in different water samples. Tetracycline (TC) is the second most widely used antibiotics in the world and is used as chelating agent. To the best of our knowledge, this is the first work that an antibiotic is used as a chelating agent for CPE of UO22+. Besides, the use of TC as complexing agent provides excellent chelating features. TC molecule has large numbers of functional groups (adjacent hydroxyl oxygen atoms and cyclohexanone oxygen atoms, amide groups) which can form stable complex with UO22+. After complexation with TC, UO22+ ions were quantitatively recovered in Triton X-100 after cooling in the ice bath. 3.0 mL of acetate buffer was added to the surfactant-rich phase prior to its analysis by UV-Vis spectrophotometer. The influence of analytical parameters including pH, buffer volume, TC, Triton X-100 concentrations, bath temperature, incubation time were optimized. The effect of the matrix ions on the recovery of UO22+ ions was investigated. The limit of detection was 0.0746 mu g mL(-1) along with enrichment factor of 14.3 with a R. S. D. of 3.6 %. The proposed procedure was applied to the analysis of various environmental water samples. On the other hand, the electronic distribution of TC molecule is investigated with their frontier molecular orbital density distributions.
Imidazole octasubstituted novel mono and double-decker phthalocyanines: Synthesis, characterization, electrical and gas sensing properties
(PERGAMON-ELSEVIER SCIENCE LTD, 2018) Yabas, Ebru; Sulu, Mustafa; Dumludag, Fatih; Salih, B.; Bekaroglu, Ozer
Imidazole disubstituted phthalonitrile (1) was prepared by the reaction of 4,5-dichlorophthalonitrile with 4,5-diphenyl-1H-imidazolethiole. Imidazole octasubstituted metal free (2), zinc(II) (3), cobalt(II) (4) monophthalocyanines and lutetium(III) (5) and europium(III) (6) double-decker phthalocyanines were prepared by cyclotetramerization of compound 1. The new compounds were characterized by H-1 NMR, C-13 NMR, UV-vis, IR, MALDI-TOF mass, ESR spectra and elemental analysis. Dc and ac conductivity and gas sensing properties (at room temperature) of the compounds of 2-6 were studied between the temperatures of 295-523 K. Ac conductivity values of the films were measured in the frequency region of 40 Hz-100 kHz. The films were tested for the vapors of toluene, ethanol, THF, n-hexane, chloroform and xylene. DC conductivity results revealed that the compounds 2-6 show a semiconductor behavior. Results of ac measurements show dominant conduction mechanism can be modeled depending on temperature and frequency. The best sensitivity values were obtained for the xylene vapors. The sensor 3 showed best sensitivity among the other sensors for xylene vapor. Response times of the sensors were also determined. (C) 2018 Elsevier Ltd. All rights reserved.
Improved thermoelectric properties by copolymerization of conducting with insulating monomers on carbon nanotubes
(Elsevier Science Sa, 2024) Erden, Fuat; Danaci, Ilhan; Oner, M. Rasit; Yabas, Ebru; Ozbay, Salih
In the present work, development of carbon nanotube (CNT)/poly(conducting-co-insulating monomer) structures was proposed to improve the thermoelectric (TE) performance in CNT/polyaniline (PANI) composites. To check the validity of this idea, we prepared multiwalled carbon nanotube (MWNT)/poly(aniline- co -acrylonitrile) composites by in-situ inverted emulsion copolymerization, and applied secondary doping with camphorsulfonic acid in m-cresol medium prior to the investigation of TE properties. The samples were characterized by FT-IR, UV -Vis, 1 H NMR, DSC, GPC, CHNS elemental analysis, intrinsic viscosity, SEM, XRD, electrical resistance, Seebeck coefficient, thickness, and Hall measurements. We report that nitrile groups were hydrolyzed during the polymerization reactions to provide a polymer structure exhibiting aniline, acrylamide, acrylic acid, and glutarimide groups. Further, the poly(aniline- co -acrylonitrile) that prepared in the present work were random copolymers. Importantly, we found that 30 % MWNT/70 % poly(90ANI- co -10AN) composite exhibited a 63 % higher power factor ( PF ) of 5.48 mu W/mK 2 ( a : 225 S/cm, S : 15.6 mu V/K) at 35 degrees C than that of 30 % MWNT/70 % PANI, which exhibited a PF of about 3.37 mu W/mK 2 ( a : 238 S/cm, S : 11.9 mu V/K). This was ascribed to the decrease of carrier concentration together with the increase of carrier mobility in the 30 % MWNT/70 % poly(90ANI- co10AN) composite as compared to the 30 % MWNT/70 % PANI.
Lu, Sm, and Y-based double-decker phthalocyanines with enhanced photodynamic therapy performance
(Pergamon-Elsevier Science Ltd, 2024) Zeki, Ketrin; Yabas, Ebru; Erden, Fuat; Salih, Bekir; Canlica, Mevlude
This paper focuses on the preparation of 3,5-di-tert-butylphenoxy substituted Lu, Sm, and Y-based double-decker phthalocyanines (Pcs), and investigation of their PDT properties. Briefly, 1,8,15,22-tetra-(3,5-di-tert-butylphenoxy) bisphthalocyanine derivatives (denoted LuPc2-3, SmPc2-4, YPc2-5) were synthesized by a two-step process. First, metal-free 1,8,15,22-tetra-(3,5-di-tert-butylphenoxy)phthalocyanine was prepared by tetramerization of 3,5-di-tert-butylphenoxy phthalonitrile, which is followed by reaction of different lanthanide salts with 1,8,15,22-tetra-(3,5-di-tert-butylphenoxy)bisphthalocyanine. The resultant double-decker Pcs were characterized in detail by UV-Vis, FT-IR, 1H NMR, fluorescence spectroscopy, MALDI-TOF MS, and elemental analysis. Strikingly, we report that double-decker phthalocyanines are not only photostable, but also exhibit relatively high singlet oxygen quantum yields of 0.96 (LuPc2-3), 0.91 (SmPc2-4) 0.87 (YPc2-5) and in THF.
New cobalt phthalocyanine-graphene oxide hybrid nanomaterial prepared by strong ?-? interactions
(Springer, 2022) Yabas, Ebru
In this study, a novel hybrid nanomaterial was obtained by interaction of cobalt phthalocyanine (CoPc) derivative on the surface of graphene oxide (GO) producing a CoPc-GO supermolecular system in which interaction is occurred by the pi-pi stacking. The CoPc-GO hybrid was prepared in a much shorter time than the examples in the literature, and it was observed that this nanomaterial was quite stable at room conditions and during dilution. The obtained hybrid nanomaterial was analyzed by scanning electron microscopy (SEM) and spectroscopic methods. Spectroscopic measurements indicate that immediate intermolecular interactions are occurring during the mixing of GO and CoPc. SEM studies show that CoPc successfully interacts with GO. Significant color changes were also observed by the addition of GO solutions at different concentrations on the CoPc solution. Also, we determined the optical band gap of the CoPc-GO nanohybrid using UV-Vis spectroscopy technique. It was also determined that the stable CoPc-GO hybrid, which can be prepared very quickly and easily, has the potential to be used in optoelectronic applications.
Novel re duce d graphene oxide/zinc phthalocyanine and re duce d graphene oxide/cobalt phthalocyanine hybrids as high sensitivity room temperature volatile organic compound gas sensors
(Elsevier, 2023) Yabas, Ebru; Bicer, Emre; Altindal, Ahmet
In this work, novel 4-pyridynyl-oxadiazole tetrasubstituted zinc and cobalt phthalocyanine compounds were synthesized and characterized by UV-vis, Fluorescence spectroscopy, and SEM. Then these com-pounds were mixed with reduced graphene oxide. As a result of the interaction of these newly syn-thesized phthalocyanines with reduced graphene oxide (rGO), rGO/ZnPc and rGO/CoPc hybrids were ob-tained. The measurement results confirm that the prepared non-covalent rGO/ZnPc and rGO/CoPc hybrid structures are formed by strong pi-pi interaction. A comparative study of the sensor response of rGO and non-covalently functionalized with zinc and cobalt phthalocyanines (rGO/ZnPc, and rGO/CoPc) hybrids to five different volatile organic compound vapors, ammonia, acetone, ethanol, methanol and butanol is car-ried out. The response of the sensors increases with respect to ammonia concentrations ranging from 30 to 210 ppm. The response time for 120 ppm ammonia vapor were approximately 250s, 230s and 190s for rGO, rGO/ZnPc, and rGO/CoPc based sensors, respectively. Also, we have conducted selectivity exper-iments with the aformentioned vapors, thus, studies have indicated that functionalization of rGO with ZnPc results in a 43-fold improvement in sensor response towards ammonia vapors. (c) 2022 Elsevier B.V. All rights reserved.
Photodynamic activity of cationic ball-type zinc phthalocyanine in cell culture experiments with MCF-7 and MG63 cancer cells
(World Scientific Publ Co Pte Ltd, 2024) Soylu, Sinan; Bagda, Efkan; Altun, Ahmet; Bagda, Esra; Kurt, Atilla; Erden, Fuat; Yabas, Ebru
Effective binding of cationic ball-type zinc phthalocyanine (BT-Pc) to G-quadruplex (G4) DNA molecules has already been demonstrated previously. This motivated us to investigate the PDT performance of BT-Pc in cell culture studies. Accordingly, the present work involves the application of BT-Pc to breast (MCF-7) and osteosarcoma (MG63) cancer cells, and also to healthy fibroblast cells (L929). Cell lines (CL) were irradiated at 640 nm wavelength, and the photodynamic activity was evaluated. The results show that cytotoxicity was significantly stronger in MCF-7 cells than in both L929 and MG63 cells (p < 0.05) in the absence of IPL irradiation. Also, we report that the application of l IPL provided significant photodynamic activity in MCF-7 and MG63 cells (p < 0.05). These results further suggest that BT-Pc might become a promising photosensitizer for future clinical trials.
Synthesis of (2R,3S)-2-(3,4-Dihydroxy phenyl)chroman-3,5,7-triol Derivative Boron Compounds: Antioxidant, Enzyme, Antimicrobial, and Antibiofilm Activities
(Wiley-V C H Verlag Gmbh, 2025) Pasa, Salih; Atlan, Metin; Temel, Hamdi; Ertas, Abdulselam; Yabas, Ebru; Dincer, Emine
(2R,3S)-2-(3,4-dihydroxyphenyl)chroman-3,5,7-triol compound corresponds to catechin, which is from the flavanol class of flavonoids and has many pharmacological effects such as anticarcinogenic, antioxidant, dermatological, antihypertensive, antiviral, antimutagenic, antidiabetic. The aim of this study is to investigate novel drug candidates for several human diseases composed of catechin and boronic acid derivatives. Catechin was modified by various types of boronic acid compounds. In the derivatization experiment, phenyl boronic acid, 6-methoxy naphthalene boronic acid, 1,4-phenyl diboronic acid, 3-formyl phenyl boronic acid, and 4-methoxy-3-formyl phenyl boronic acid, 4-methoxy phenyl boronic acid were firstly used to modify catechin. The newly obtained compounds were structurally elucidated by 1H NMR, 13C NMR, FTIR, and LC-MS spectral techniques. All novel derivatives were examined for antioxidant (with particular methods such as ABTS, DPPH, and CUPRAC), enzyme, and antibiofilm activities. Most compounds were determined to be more active or effective than those standard compounds. Among all derivatives, CB-2 showed the highest inhibition of enzymes and the highest antioxidant activities. Biological results revealed that the boronic-modified compounds could be designed as potential antioxidants, enzymes, antimicrobials, and antibiofilm agents.
Synthesis, characterization and investigation of electrical and electrochemical properties of imidazole substituted phthalocyanines
(ELSEVIER SCIENCE SA, 2011) Yabas, Ebru; Sulu, Mustafa; Saydam, Sinan; Dumludag, Fatih; Salih, Bekir; Bekaroglu, Ozer
Compound 1 has been synthesized by the reaction of 4-nitrophthalonitrile and 4,5-diphenyl-1H-imidazolethiole in DMSO in the presence of K2CO3. Compound 2 has been synthesized by heating compound 1 with metallic lithium in pentanol and hydrolyzed with hydrochloric acid (10%) and then neutralized with ammonia solution. Compound 3 and 4 have been synthesized by heating 1 with ZnCl2 or CoCl2 in DMF in the presence of 1,8-diazabicyclo[5.4.0] undec-7-ene (DBU), respectively. The new compounds were obtained in sufficient purity after successive washing with different solvents and were characterized by elemental analysis, H-1 NMR, C-13 NMR, UV-vis, IR and mass spectra. We also studied aggregation behavior, electrochemical and electrical properties of these phthalocyanines. Direct current (dc) and alternating current (ac) conductivity (40-100 kHz) measurements of films of 2, 3 and 4 were performed in the temperature range of 295-523 K. Impedance spectra (IS) of the 2, 3 and 4 were also studied. The conduction processes were discussed. Temperature dependence of dc conductivity of the films revealed that 2, 3 and 4 show a semiconductor behavior. Results of ac measurements showed that, conduction processes of the films of the complex consisted of different mechanisms depending on temperature and frequency. (C) 2010 Elsevier B.V. All rights reserved.
The new metal-free, zinc, magnesium, indium ball-type phthalocyanines and their hybrids with graphene oxide: Synthesis, investigation of photophysical, photochemical properties and theoretical studies
(Elsevier Science Sa, 2025) Zeki, Ketrin; Asrak, Sueda; Yabas, Fatma Nur; Cevik, Nergis; Yabas, Ebru; Khene, Samson; Salih, Bekir
In this study, four ball-type phthalocyanines (BTPc-H2-4, BTPc-Zn-5, BTPc-Mg-6, BTPc-In-7) were synthesized from 3,3 ',((3,5-di-tert-butyl-1,2-phenylene)bis(oxy)diphthalonitrile in a single reaction step. Non-covalent balltype phthalocyanine (BTPc)-graphene oxide (GO) hybrids (BTPc-GO) were prepared by simple sonication method. The structures were confirmed by elemental analysis, ultraviolet-visible (UV-Vis), fourier-transform infrared (FT-IR), proton nuclear magnetic resonance (1H NMR), MALDI-TOF MS spectroscopies, elemental analysis and scanning electron microscope (SEM). The photophysical and photochemical properties of ball-type phthalocyanines were investigated in dimethyl sulfoxide (DMSO) and tetrahydrofuran (THF). In this way, the contribution of solution polarity to these properties was compared. The contribution of GO was examined by examining the singlet oxygen quantum yields of BTPc-GO hybrids in DMSO. In addition, the structural properties of ball-type phthalocyanines were examined through theoretical studies and the effect of structural properties on experimentally determined band gaps was examined. Interestingly, we also report that ball-type thalocyanines are both photostable and exhibit extremely high singlet oxygen quantum yields. In addition, we can state that hybrids of these compounds with GO also show the ability to increase the singlet oxygen quantum yield, depending on the degree of interaction.
Two-Photon Absorption Response of Functionalized BODIPY Dyes in Near-IR Region by Tuning Conjugation Length and Meso-Substituents
(Amer Chemical Soc, 2023) Yildiz, Elif Akhuseyin; Unlu, Bekir Asilcan; Karatay, Ahmet; Bozkurt, Yasemin; Ozler, Muhammed Emre; Sozmen, Fazli; Yabas, Ebru
BODIPY dyes substituted by phenol or -COOMe unitsat themeso-position (C8) with and without a distyryl group including a methoxymoiety at the -C3 and -C5 positions of the BODIPY have been synthesizedto analyze the photophysical properties. To clarify the ground-stateinteraction, absorption and emission features were investigated inthe THF environment. Extending the & pi;-conjugation with the methoxymoiety at -C3 and -C5 positions of BODIPY leads to a spectral shiftingof the absorption maxima toward red by 120 nm. In addition, attachingthe -COOMe unit at the meso-position of the BODIPY structureincreases nonradiative molecular relaxation as compared to compoundspossessing phenol substituents at the same position. We have investigatedthe effect of phenol and a -COOMe group and & pi;-extendedconjugation length with a methoxy moiety on the properties of two-photonabsorption (TPA) and electron transfer dynamics by performing open-aperture(OA) Z-scan and femtosecond transient absorption spectroscopy measurements,respectively. The synthesized BODIPY compounds with the distyryl groupincluding the methoxy unit show TPA character due to the longer conjugationlength and therefore intramolecular charge transfer ability. Basedon the OA Z-scan experiments upon photoexcitation with 800 nm pulsedlaser light, TPA cross-section values were obtained as 74 and 81 GMfor the compounds possessing phenol and -COOMe units at themeso-position of BODIPY treated by distyryl group with methoxy moieties,respectively. Additionally, optical and electronic properties werecalculated theoretically by using the DFT method.
The water soluble ball-type phthalocyanine as new potential anticancer drugs
(ELSEVIER SCI LTD, 2015) Yabas, Ebru; Bagda, Efkan; Bagda, Esra
Compound 1 has been prepared by the reaction of 4-nitrophthalonitrile with triethanolamine. Compound 3 has been synthesized with quaternarization of compound 2 which prepared by cyclotetramerization of compound 1. The synthesized compounds have been characterized by elemental analysis, H-1 NMR, UV Vis, IR and MALDI-TOF MS spectral data. The interaction of compound 3 with calf thymus DNA was investigated spectrophotometrically. The phthalocyanine-DNA binding mechanism as well as the thermodynamic properties of binding was studied. The thermal denaturation profile, gel electrophoresis studies and the viscosity experiments were also conducted to clarify the mechanism. The replacement of ethidium bromide with phthalocyanine was monitored flourometrically to verify the binding mode. The Stern Volmer plot has nonlinear characteristic that implies both collisions of molecules and formation of ground state complexes which causes the fluorescence quenching. The experimental results indicate that the synthesized ball type water soluble phthalocyanine binds to calf thymus DNA via mainly intercalation. (C) 2015 Elsevier Ltd. All rights reserved.

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