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Öğe Anti-genotoxic Effects of Schiff bases and their Mn(III) Complexes Containing L-Aspartic acid and L-Phenylalanine(Gazi Univ, 2018) Özkan, Elvan Hasanoğlu; Kızıl, Hamit Emre; Şakıyan, İffet; Nartop, Dilek; Sarı, Nurşen; Ağar, GülerayThe purpose of the research was to evaluate the genotoxic and anti-genotoxic properties of Schiff bases and their Mn (III) complexes containing L-aspartic acid, and L-phenylalanine. The anti-genotoxic properties of four compounds in human lymphocytes cells were investigated by sister chromatid exchanges (SCEs) test system against aflatoxin Bi (AFBi). The results showed that compounds have strong anti-genotoxic properties.Öğe Characterization of magnetic Fe3O4@SiO(2)nanoparticles with fluorescent properties for potential multipurpose imaging and theranostic applications(Springer, 2020) Kurnaz Yetim, Nurdan; Kursun Baysak, Fatma; Koc, Mumin Mehmet; Nartop, DilekFe(3)O(4)magnetic nanoparticles (MNPs) were produced using hydrothermal synthesis and coated with tetraethyl orthosilicate (TEOS) where Fe3O4@SiO(2)MNPs with fluorescent properties were obtained. Structural characterization of the nanoparticles was performed using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Structural investigations confirmed that nanoparticles were in core@shell form. Chemical characterizations were performed using Fourier-transform infrared spectroscopy and energy-dispersive X-ray spectroscopy. Chemical investigations confirm that TEOS coating was successfully formed SiO(2)shells on Fe(3)O(4)nanoparticles. Magnetic characterizations revealed that nanoparticles show superparamagnetic properties which make them a suitable candidate for magnetic hyperthermia and magnetic resonance imaging (MRI) applications. Increased thickness of SiO(2)shell in nanoparticle structure results in decreased magnetic saturation values. Fluorescence properties of the nanoparticles were confirmed using fluorescence spectroscopy. Increased SiO(2)shell thickness results in increased fluorescent intensity. It was confirmed that Fe3O4@SiO(2)nanoparticle has the potential to be used in medical applications such as MRI, fluorescence imaging and magnetic hyperthermia, and so on.Öğe Ensuring traceability of organophosphate pesticides (OPs) through enzyme immobilized spheres(Springer, 2021) Hasanoglu ozkan, Elvan; Kurnaz Yetim, Nurdan; Nartop, Dilek; Sari, NursenCurrently, pesticide residues increasingly lead to health problems. Acetylcholinesterase enzyme (AChE) plays a role in detoxification processes due to their ability to scavenge organophosphates. Thus, this enzyme has been selected for the detection of pesticides. Herein, this study describes the preparation and application of appropriate new immobilized spheres that could be used for the detection of organophosphorus pesticide residues. That is a simple colorimetric enzymatic assay for the practical discovery of N-(Mercaptomethyl) phthalimide S-(O, O-dimethylphosphorodithioate) from organophosphorus pesticides (OPs) widely used in the treatment of sugar beet, apple, nut, corn, and tobacco. The process is based on the immobilization of acetylcholinesterase onto tryptophan FMPS-Trp, (FMPS-Trp)Pd(II), and (FMPS-Trp)Pt(II) functionalized spheres. Spectroscopic and microscopic techniques were used in the characterization of the spheres where scanning electron microscopy (SEM) is an essential tool. The (FMPS-Trp)Pt(II)-AChE showed a good affinity to acetylthiocholine chloride (ATCl) and was found to have the ability to catalyze the hydrolysis of ATCl with an apparent Michaelis-Menten constant value of 288 mM. The developed colorimetric process showed good qualitative analytical performance for Phosmet (OPs) detection as low as 10(-7) M. [GRAPHICS] .Öğe Enzyme immobilization on polymeric microspheres containing Schiff base for detection of organophosphate and carbamate insecticides(Elsevier, 2020) Nartop, Dilek; Yetim, Nurdan Kurnaz; Ozkan, Elvan Hasanoglu; Sari, NursenIn this study, polymeric microsphere including Schiff base TrisPS-pyr and TrisPS-pyr-Pt(II) were obtained by condensation reaction for improve the enzymatic properties of acetylcholinesterase (AChE) and detect harmful insects. Structures of the synthesized compounds were characterized by spectroscopic methods such as FT-IR, UV-Vis, SEM-EDX, GPC. Acetylcholinesterase enzyme was immobilized to these new polymeric microspheres and their properties such as activity, reusability and storage stability were investigated. In addition, the qualitative determination of carbamate [2,3-dihydro-2,2-dimethyl-7-benzofuranol N-methylcarbamate (carbofuran), 4-methylthio-3,5-xylyl methylcarbamate (methiocarb) and S-methyl-N- (methylcarbamoyl oxy) thioacetamide (methomyl)] and organophosphate [diethyl (dimethyl thiophosphoryl) succinate (malathion), O, S-dimethyl phosphoramidothioate acetyl (acephate) and chlorpyrifos methyl] insecticides by the immobilized enzyme was performed. The reason for the selection of these pesticides is because they are widely used to combat pests of agricultural products (hazelnut, corn, sugar beet, apple and tobacco) which are grown in our region. (C) 2019 Elsevier B.V. All rights reserved.Öğe Evulation of Antimutagenic Activity of Ni(II) Complexes with Unsymmetric Schiff Bases(2020) Nartop, Dilek; Özkan, Elvan Hasanoğlu; Kızıl, Hamit Emre; Ağar, Güleray; Sarı, NurşenIn this work, Ni(II) complexes with unsymmetric Schiff bases (NiL1, NiL2, NiL3, NiL4) were prepared by a twostage method reported by one of us recently for investigate antimutagenic properties. Sodium azide-inducedantimutagenic effect in lymphocytes was determined by sister chromatid exchange (SCE) and micronucleus (MN)methods. It has been determined that the synthesized compounds have antimutagenic properties and reduce themutagenicity caused by sodium azide (NaN3) which is used as a positive control.Öğe Magnetic dendrimer-encapsulated metal nanoparticles (Au, Ag): effect of dendrimerization on catalytic reduction of 4-nitrophenol(Springer, 2022) Yetim, Nurdan Kurnaz; Koç, Mümin Mehmet; Nartop, DilekMagnetic nanoparticles (MNPs) and nanocomposites can be used in different applications including catalysis reactions and applications. Magnetic nanocomposites can be reused and magnetically filtrated after catalysis reaction. For this purpose, Fe3O4 MNPs were produced using the co-precipitation technique. Fe3O4 MNPs were coated with SiO2 shell, APTES and G2 PAMAM dendrimers and lastly doped with Au and Ag nanoparticles (Fe3O4@G2/Au/Ag) which has been examined for the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH4 as a model reaction. Physical structures of the nanocomposites were characterized using SEM and TEM which illustrate that nanoparticles were in composite form. Chemical composition of nanostructures was confirmed using EDX and FTIR. Magnetic characteristics were checked using VSM. Dendrimerization and Au and Ag nanoparticle doping on catalytic and magnetic properties were deeply assessed. PAMAM dendrimer coating on Fe3O4 nanoparticles results in a slightly decreased magnetic saturation value and in the reaction rate of 4-NP reduction. Au and Ag embedding in PAMAM dendrimers slightly increases the reaction rate while reducing the overall magnetic saturation values of nanocomposites. [GRAPHICS] .Öğe New Antimicrobial Polymeric Microspheres Containing Azomethine(Springer, 2022) Ülke, Eyüp; Özkan, Elvan Hasanoğlu; Nartop, Dilek; Ogutcu, HaticeHerein, new polymeric microspheres containing azomethine (PS-OPA, PS-OPA-Pt, PS-OPA-Ni, PS-OPA-Mn and PS- OPA-Cu) were synthesized and investigated by elemental analysis, FT-IR, SEM-EDX, TGA-DTA, UV-Vis, GPC and magnetic susceptibility. Antibacterial and antifungal activities of the synthesized polymeric microspheres were evaluated against pathogenic bacteria (Staphylococcus epidermidis ATCC12228, Bacillus cereus RSKK863, Staphylococcus aureus ATCC25923, Enterobacter aerogenes, Pseudomonas aeroginosa sp., Klebsiella pneumonia ATCC27853, Salmonella type H NCTC9018394, Proteus vulgaris RSKK96026, Escherichia coli ATCC1280) and yeast (Candida albicans Y-1200-NIH) by the well-diffusion method for potential biomedical applications. It was determined that polymeric microspheres exhibited higher inhibition effect against B. cereus, E. aerogenes, P. aeruginosa, P. vulgaris and showed higher antifungal activity than standard nystatin. [GRAPHICS] .Öğe Novel polymeric microspheres: Synthesis, enzyme immobilization, antimutagenic activity, and antimicrobial evaluation against pathogenic microorganisms(John Wiley and Sons Inc., 2020) Nartop, Dilek; Demirel, Birtane; Güleç, Murat; Özkan, Elvan Hasanoğlu; Yetim, Nurdan Kurnaz; Sarı, Nurşen; Ağar, GülerayNew polymeric microspheres containing azomethine (1a-1c and 2a-2c) were synthesized by condensation to compare the enzymatic properties of the enzyme glucose oxidase (GOx) and to investigate antimutagenic and antimicrobial activities. The polymeric microspheres were characterized by elemental analysis, infrared spectra (FT-IR), proton nuclear magnetic resonance spectra, thermal gravimetric analysis, and scanning electron microscopy analysis. The catalytic activity of the glucose oxidase enzyme follows Michaelis-Menten kinetics. Influence of temperature, reusability, and storage capacity of the free and immobilized glucose oxidase enzyme were investigated. It is determined that immobilized enzymes exhibit good storage stability and reusability. After immobilization of GOx in polymeric supports, the thermal stability of the enzyme increased and the maximum reaction rate (Vmax) decreased. The activity of the immobilized enzymes was preserved even after 5 months. The antibacterial and antifungal activity of the polymeric microspheres were evaluated by well-diffusion method against some selected pathogenic microorganisms. The antimutagenic properties of all compounds were also examined against sodium azide in human lymphocyte cells by micronuclei and sister chromatid exchange tests. © 2019 Wiley Periodicals, Inc.Öğe Qualitative enzymatic detection of organophosphate and carbamate insecticides(Taylor & Francis Inc, 2020) Nartop, Dilek; Hasanoglu Ozkan, Elvan; Yetim, Nurdan Kurnaz; Sari, NursenIn this study, new polymers containing amides (TrisPS-Ntaa, andTrisPS-Ntaa-Fc) were synthesized by condensation reaction for qualitative identification of insecticides. The synthesized polymers, including amides were investigated by infrared spectroscopy (IR), scanning electron microscopy-energy dispersion X- ray spectrometry (SEM-EDX), and gel permeation chromatography (GPC). Then, acetylcholinesterase enzyme (AChE) was covalently immobilized on these polymers to improve properties (including activity, reusability, and storage stability). Accordingly, organophosphate (malathion, acephate, chlorpyrifos methyl) and carbamate (carbofuran, methiocarb, methomyl), which are used to prevent harmful organisms in some agricultural products were enzymatically determined based on their inhibitory activity on AChE.Öğe Synthesis and characterization of Au and Bi2O3 decorated Fe3O4@PAMAM dendrimer nanocomposites for medical applications(Springer Heidelberg, 2021) Kurnaz Yetim, Nurdan; Kursun Baysak, Fatma; Koc, Mumin Mehmet; Nartop, DilekFe3O4 magnetic nanoparticles were produced and covered with TEOS and APTES which were known to reduce the toxic properties of nanoparticles. Nanoparticles were functionalized second-generation PAMAM dendrimers and doped with Au and Bi2O3 nanoparticles where Fe3O4@G2/Au/Bi2O3 nanocomposites were obtained for potential multimodal imaging applications. Physicals structures of the nanocomposites were characterized using SEM and TEM which illustrate that nanoparticles were in composite form. Chemical composition of nanostructures was confirmed using EDX and FTIR. Magnetic characteristics were checked using VSM. It was seen that nanoparticles have superparamagnetic properties which indicate that nanocomposites have potential to be used in MRI and magnetic hyperthermia applications. X-ray imaging properties were confirmed using X-ray imaging and CT imaging. It was confirmed that doping nanoparticles with Au and Bi2O3 nanoparticles significantly enhanced the X-ray tomography contrast enhancement properties which illustrate the theranostic properties of the nanocomposites.Öğe Synthesis and characterization of novel polystyrene-silica composites containing azomethine(Elsevier, 2021) Nartop, Dilek; Kazak, CigdemHerein, four novel polystyrene / silica composites containing azomethine (Si-PSNO2, Si-PSH, Si-PSCl, Si-PSCH3) were reported. For this purpose, polymers including azomethine (PSNO2, PSH, PSCl, PSCH3), one of which is novel (PSNO2) were obtained from condensation reaction between 4-benzyloxybenzaldehyde with 2-aminophenol and its derivatives. Then, these polymers were immobilized on 3-chloropropyl functionalized silica gel to obtain polymer / silica composites. The structures of novel composites were characterized by various spectroscopic techniques (IR, GPC, TG-DTA, SEM-EDX, EA, ICP-MS, optical profilometer). (C) 2020 Elsevier B.V. All rights reserved.Öğe Synthesis and in Vitro Antimicrobial Evaluation of Novel Potent Bioactive Heterocyclic Compounds(Taylor & Francis Ltd, 2023) Macit, Ahsen Zeynep; Hasanoglu Ozkan, Elvan; Ogutcu, Hatice; Nartop, DilekIn the present work, the antibacterial and antifungal properties of six new heterocyclic Schiff bases (HSb1, HSb2, HSb3, HSb4, HSb5, HSb6) were evaluated as potential bioactive compounds against the disease-causing pathogenic microorganisms (S.epidermidis, S.aureus, B.cereus RSKK863, E.aerogenes, P.aeroginosa sp., K. pneumonia, S. type H, P.vulgaris, E. coli and (C.albicans Y-1200-NIH). The well-diffusion-method was used to determine the antimicrobial activity. For this purpose, heterocyclic Schiff bases were synthesized by condensation reaction of aldehyde derivatives and thiosemicarbazide derivatives. Spectral analysis techniques (organic elemental analysis, FT-IR,H-1-NMR, HRMS, SEM-EDX) were used to characterize the synthesized compounds. It was determined that all the newly synthesized heterocyclic Schiff bases exhibited sound, high or moderate inhibitory effects on the growth of selected different standard antibiotics. [Graphical Abstract]Öğe Synthesis, antimicrobial and antimutagenic effects of novel polymeric-Schiff bases including indol(Elsevier Science Bv, 2019) Nartop, Dilek; Özkan, Elvan Hasanoğlu; Gündem, Mehmet; Çeker, Selçuk; Ağar, Güleray; Öğütcü, Hatice; Sarı, NurşenHerein, the synthesis and characterization of three new polymeric-Schiff bases including indol (L-1, L-2, L-3) were reported. The antibacterial and antifungal activity of all compounds were investigated by the well-diffusion method against some selected microorganisms as potential antimicrobial agents. In addition, the anti-genotoxic properties of these polymeric-Schiff bases were examined against sodium azide in human lymphocyte cells by micronuclei (MN) and sister chromatid exchange (SCE) tests. (C) 2019 Elsevier B.V. All rights reserved.Öğe Synthesis, characterization and investigation of tautomeric, potentiometric and antimicrobial properties of a novel unsymmetric Schiff base and its Fe(III) and Ni(II) complexes(Univ Mohammed Premier Oujda, 2017) Nartop, Dilek; Özdemir, Özlem; Gürkan, PerihanA new unsymmetric Schiff base [(2OH) R-CH=N-(C6H4)-CH=N-R'(2OH) R=phenyl, R' = naphthyl] with its Fe(III) and Ni(II) complexes were synthesized by a two step method. Diimine Schiff base and its complexes were characterized by elemental analysis, mass spectra, IR, H-1/C-13-NMR spectra, TGA analysis, electronic and magnetic measurements. The phenol-imine and keto-amine tautomerism of the unsymmetric Schiff base was investigated with NMR techniques and UV-visible spectra in different solvents. Also, the protonation constants of the ligand and the stability constants of its Ni(II) and Fe(III) complexes were determined potentiometrically in 1:1(v/v) ethanol-water mixture at an ionic strength of 0.5 mol.L-1 KCl and at 25.0 +/- 0.1 degrees C. The antifungal, antimicrobial activities and the minimum inhibitory concentration (MIC) values of the compounds were evaluated against Escherichia coli (0157:H7), Micrococcus luteus (NRRLB 4975), Bacillus cereus (RSKK 863) and Candida albicans (ATCC 16231).
