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Öğe Anoxybacillus sp. SO B1-Immobilized Amberlite XAD-16 for Solid-Phase Preconcentration of Cu(II) and Pb(II) and Their Determinations by Flame Atomic Absorption Spectrometry(Taylor & Francis Inc, 2015) Oral, Elif Varhan; Ozdemir, Sadin; Dolak, Ibrahim; Okumus, Veysi; Dundar, Abdurrahman; Ziyadanogullari, Berrin; Aksoy, ZehraA new method for the determination of Cu(II) and Pb(II) by flame atomic absorption spectrometry (FAAS) after preconcentrating on a column containing Anoxybacillus sp. SO B1-immobilized Amberlite XAD-16 was developed. The functional groups of Anoxybacillus sp. SO B1 immobilized on Amberlite XAD-16 were characterized in KBr tablets by Fourier transform infrared (FT-IR) spectrometry. Various parameters such as pH, amount of the adsorbent, eluent type and volume, and flow rate of the sample solution were studied. The optimum pH values of quantitative sorption for Cu(II) and Pb(II) were found to be pH 7.0 and 5.0 and Cu(II) and Pb(II) ions could be quantitatively eluted with 5.0ml of 1.0mol L-1 HCI and 10.0ml of 0.25mol L-1 HNO3, respectively. Recoveries of Cu(II) and Pb(II) were found to be 100.9 +/- 1.57% and 100.3 +/- 0.49% (N = 5), the limits of detection of Cu(II) and Pb(II) in the determination by FAAS (3s, N = 10) were found to be 0.8 and 1.6 mu g L-1, respectively. The proposed enrichment method was applied for metal ion determination from water samples such as two parts of Tigris River water in Diyarbakir and Elazig, Lake of Hazar in Elazig, and tap water in Diyarbakir. Furthermore, the accuracy of the proposed method was verified by studying the analytical recovery and by analyzing certified reference material (NCS-DC 73350 leaves of poplar).Öğe Antioxidant Properties of Cultured Mycelia from Four Pleurotus Species Produced in Submerged Medium(Taylor & Francis Inc, 2013) Dundar, Abdurrahman; Okumus, Veysi; Ozdemir, Sadin; Yildiz, AbdunnasirThe ethanolic extracts of dried cultured mycelia of Pleurotus ostreatus, Pleurotus eryngii, Pleurotus florida, and Pleurotus sajor-caju were analyzed for antioxidant activity in different systems. Tests used are as follows: reducing power, free radical scavenging, superoxide anion radical scavenging, total antioxidant activity, metal chelating activitiy, etc.; total phenolic content was determined. The percentage inhibition of P. ostreatus, P. eryngii, P. florida, and P. sajor-caju at 20 mg/mL concentration on peroxidation in a -carotenelinoleic acid system was 57.19, 60.68, 62.12, and 58.81%, respectively. The reducing power of P. eryngii was higher than the other samples, and its value was 0.86 at 10 mg/mL concentration. P. ostreatus and P. sajor-caju proved to be better at scavenging superoxide anion radicals than the P. eryngii and P. florida. In the scavenging effect of DPPH radical test, P. ostreatus showed the highest activity potential and P. sajor-caju showed the strongest metal chelating capacity.Öğe Application of Half-Sandwich Metal-Phosphinite Compounds to Biological Activities: Determine the energies of the HOMO and LUMO levels(Wiley-V C H Verlag Gmbh, 2023) Meric, Nermin; Rafikova, Khadichakhan; Zazybin, Alexey; Guzel, Remziye; Kayan, Cezmi; Karakas, Duygu Elma; Dundar, AbdurrahmanMononuclear transition metal complexes 1-(furan-2-yl)ethyldiphenyl[dichloro(eta(6)-p-cymene)ruthenium(II)]phosphinite, (2), 1-(furan-2-yl)ethyldiphenyl[dichloro(eta(6)-benzene) ruthenium(II)] phosphinite (3), 1-(furan-2-yl)ethyldipheny[chloro(eta(4)-1,5-cyclooctadiene)rhodium(I)]phosphinite (4), 1-(furan-2-yl)ethyldiphenyl[dichloro (eta(5)pentamethylcyclopentadienyl)iridium (III)] phosphinite (5) were synthesized and characterized by microanalysis, infrared, MS, and NMR spectroscopy. The biological activities of the complexes were also tested. Compounds 2 and 5 were the best complexes at DPPH radical scavenging and reducing power activity at 73.27 % and 0.41 at 200 mu g/mL, respectively. The highest antimicrobial activity exhibited by complex 3 as 14 mm inhibition zone against S. aureus. All of the complexes have cleaved the DNA from the double-strand and exhibited three bands on gel electrophoresis. Moreover, cyclic voltammetry studies of the phosphinite complexes were carried out to determine the energies of the HOMO and LUMO levels as well as to estimate their electrochemical and some electronic properties.Öğe Biosorption of 2,4-d, 2,4-DP, and 2,4-DB from aqueous solution by using thermophilic anoxybacillus flavithermus and analysis by high-performance thin layer chromatography: Equilibrium and kinetic studies(Wiley, 2012) Ozdemir, Sadin; Bekler, Fatma Matpan; Okumus, Veysi; Dundar, Abdurrahman; Kilinc, ErsinIn this study, the potential biosorption characteristics of the thermophilic Anoxybacillus flavithermus (A. flavithermus) was investigated for the removal of the chlorophenoxy acid derivates, namely, 2,4-dichlorophenoxy acetic acid (2,4-D), 2,4-dichlorophenoxy propanoic acid (2,4-DP or dichlorprop), and 2,4-dichlorophenoxy butyric acid (2,4-DB). The experiments were performed for the simultaneous biosorption of the studied pesticides. Optimum biosorption conditions were determined as a function of contact time, pH of the solution, amount of biomass, and initial pesticides concentrations. The concentrations of the pesticides in the remaining solutions were simultaneously analyzed by high performance thin layer chromatography. The optimum parameters were found as pH: 4.0 for biosorption medium, 60 min of contact time, 50 mg of bacteria, and 50 mg L-1 of initial pesticides concentrations. Langmuir and Freundlich models were applied to describe the biosorption isotherm of the pesticides by A. flavithermus as biomass. Biosorption of pesticides on to A. flavithermus showed pseudo first-order rate kinetics at different initial concentration of pesticides and different temperatures. The experimental adsorption data were fitted both the Langmuir and Freundlich adsorption models. Fourier-transform Infrared spectroscopy was used to understand the bonding mechanism of pesticides to biosorbent and surface functionality of the biosorbent The highest pesticide uptake was calculated from Langmuir isotherm and found to be 24.15 mg g-1 for 2,4-D. Among the studied pesticides, 2,4-DP showed difference adsorption behavior. According to in your comments the reason of this that 2,4-DP contain an asymmetric carbon atom, which provide a molecular chirality. (C) 2011 American Institute of Chemical Engineers Environ Prog, 2011Öğe Biosorption of chlorophenoxy acid herbicides from aqueous solution by using low-cost agricultural wastes(Taylor & Francis Inc, 2015) Okumus, Veysi; Celik, K. Serdar; Ozdemir, Sadin; Dundar, Abdurrahman; Kilinc, ErsinThe potential biosorption abilities of apple shell (AS), orange peel (OP), banana peel (BP), and millet waste (MW) as a bio-waste material to remove 2,4-dichlorophenoxy acetic acid (2,4-D), 2,4-dichlorophenoxy propanoic acid (2,4-DP), and 2,4-dichlorophenoxy butyric acid (2,4-DB) from aqueous solution were investigated in batch condition. Optimum biosorption conditions were determined as a function of contact time, pH of the solution, amount of biomass, and initial pesticide concentrations. The concentrations of the pesticides in the remaining solutions were simultaneously determined by high performance thin layer chromatography. Langmuir and Freundlich models were applied to describe the biosorption isotherm of the pesticides by agricultural wastes. The experimental adsorption data were fitted to Langmuir adsorption models (r(2)>0.99). It was found that adsorption of 2,4-DP was higher for all biosorbent. The highest maximum adsorption capacities of 2,4-DP were found as 40.08, 22.71, 33.26, and 45.45mg/g, respectively, for AS, OP, BP, and MW. Maximum adsorption capacity was obtained for 2,4-D as OP>MW>BP>AS, 2,4-DP as MW>AS>BP>OP, and 2,4-DB as OP>AS>BP>MW. From the results, it can be said that MW was an effective biosorbent for removal of 2,4-DP and OP was an effective biosorbent for removal of 2,4-D and 2,4-DB through the studied pesticides. Optimum biosorption conditions were determined as 60min of contact time, 100mg of biomass, AS at pH 6.0, OP at pH 6.0, MW at pH 7.0, and BP at pH 7.0. FT-IR was employed to understand the surface properties of biosorbents. According to the results, agricultural wastes have high adsorption capacity.Öğe Determination of cytotoxic, anticholinesterase, antioxidant and antimicrobial activities of some wild mushroom species(Informa Healthcare, 2016) Dundar, Abdurrahman; Okumus, Veysi; Ozdemir, Sadin; Celik, Kadir Serdar; Boğa, Mehmet; Ozcagli, ErenIn the performed study of methanol extraction of wild edible mushroom species; Agaricus arvensis, Agaricus campestris, Armillaria mellea, Fomes fomentarius, Coprinus micaceus, Coriolus versicolor and Lactarius deliciosus were examined for screening their cytotoxic, anticholinesterase, antioxidant and antimicrobial capacity. Phenolic acid composition of mushrooms was also analysed. L. deliciosus and F. fomentarius were generally showed the highest activities at antioxidant test systems (metal chelating, superoxide anion radical scavenging, total antioxidant, 2,2-diphenyl-1-picrylhydrazyl radical scavenging and reducing power activity tests). The highest activities at antimicrobial activity displayed by A. arvensis and as 18 ± 0.8 against to Staphylococcus aureus. The best IC50 values of mushroom methanol extracts at anticancer activities on HeLa and NRK-52E were 7.09 and 18.23 mg/mL exhibited by C. micaceus and A. campestris, respectively. The highest butyrylcholinesterase activity exhibited by L. deliciosus. Total amount of phenolic acids were found as 1,224.70 mg/kg at L. deliciosus. © 2016 The Author(s). This open access article is distributed under a Creative Commons Attribution (CC-BY) 4.0 license.Öğe Isolation of a thermophilic Anoxybacillus flavithermus sp nov and production of thermostable ?-amylase under solid-state fermentation (SSF)(Bmc, 2012) Ozdemir, Sadin; Matpan, Fatma; Okumus, Veysi; Dundar, Abdurrahman; Ulutas, Mehmet Sefa; Kumru, MertA new bacteria was isolated from hot-spring water of Gazligol, Afyonkarahisar in Turkey. Based on morphological and biochemical tests and 16S rRNA gene sequence analysis, the isolate belonged to the Anoxybacillus flavithermus species which has 99% similarity with the bacterium DNA. The production of alpha-amylase by thermophilic Anoxybacillus flavithermus was investigated under solid-state fermentation by using some agricultural waste as substrates. Solid substrates such as rice husk, banana husk, millet, water melon husk, lentil bran, wheat bran and maize oil cake were studied for enzyme production. Of these, rice husk was proved as the best substrate for alpha-amylase production (1,271 U/mg). The maximum alpha-amylase production was observed as 1,803 U/mg at 72 h, 1,000 mu m particle size, 70% initial moisture content (w/v), and 40% inoculum level (v/w). Among the various nitrogen sources tested, 1% peptone (3,170 U/mg) was found to be the best nitrogen source for alpha-amylase production. As additional carbon sources, 1% starch (2,364 U/mg) enhanced alpha-amylase production. The optimum temperature for the activity of alpha-amylase was found to be 70A degrees C. The enzyme was optimally active at pH 6.0 and stable in the pH range of 6.0-8.0.Öğe Metallo and metal free phthalocyanines bearing (4-(1(4-phenoxyphenyl)-1-phenylethyl)phenol substituents: Synthesis, characterization, aggregation behavior, electronic, antioxidant and antibacterial properties(Elsevier Science Sa, 2014) Agirtas, M. Salih; Guven, M. Emin; Gumus, Selcuk; Ozdemir, Sadin; Dundar, AbdurrahmanAs starting material the phthalonitrile derivative bearing (4-(1(4-phenoxyphenyl)-1-phenylethyl)phenol substituents at peripheral position was prepared by a nucleophilic displacement reaction. Cyclotetramerization of 4-(4-(1-(4-hydroxyyphenyl)-1-phenylethyl)phenoxy)phthalonitrile derivative in the presence of corresponding metal salts gave the new metallophthalocyanines. Metal free phthalocyanine was obtained from the reaction of 4-(4-(1-(4-hydroxyyphenyl)-1-phenylethyl)phenoxy)phthalonitrile units. The novel compounds have been characterized by using various spectroscopic data. The aggregation investigations carried out in different concentrations indicate that 4-(4-(1-(4-hydroxyyphenyl)-1-phenylethyl)phenoxy)phthalocyanine compounds do not have any aggregation behavior for the concentration range of 10(-4)-10(-5) M in tetrahydrofuran. The antioxidant activities of novel compounds were analyzed through radical scavenging ability of 1,1-dipheny1-2-picrylhydrazyl, chelating ability to ferrous ions and reducing power. In addition to these, the antibacterial activities of compounds were investigated. Moreover, the ground-state geometries of the complexes were optimized using B3LYP/6-31G(d,p) level of density functional theory in order to predict the three-dimensional geometries and electronic structure. (C) 2014 Elsevier B.V. All rights reserved.Öğe Metallo Phthalocyanines bearing 2-Isopropyl-6-methylpyrimidin-4-yloxy Substituents: Synthesis, Characterization, Aggregation Behavior, Antioxidant and Antibacterial Activity, and Electronic Properties(Wiley-V C H Verlag Gmbh, 2014) Agirtas, M. Salih; Dede, Emrah; Gumus, Selcuk; Dundar, Abdurrahman; Okumus, VeysiA novel phthalonitrile derivative bearing 2-isopropyl-6-methylpyrimidin-4-yloxy substituents at peripheral positions was synthesized by a nucleophilic substitution reaction. Metallophthalocyanines were obtained from the reaction of the novel phthalonitrile with metal Zn, Cu, Co, and Ni salts. The characterization of the compounds was performed using elemental analysis as well as UV/Vis, FT-IR, and H-1-NMR spectroscopy. The aggregation behaviors of phthalocyanine complexes were also investigated. These metallophthalocyanines do not show any aggregation behavior between 10 (4)-10 (6) M concentration range in THF. The antioxidant activities of the synthesized compounds were evaluated using three different tests: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, metal chelating activity, and reducing power assays. All the compounds exhibited various antioxidant activities. In addition, antimicrobial activity of the compounds was tested over four gram positive and two gram negative bacteria. Moreover, the ground-state geometries of the complexes were optimized using density functional theory (DFT) methods at B3LYP/6-31G(d,p) level in order to obtain information about the 3D arrangements and electronic structure.Öğe Mononuclear Complexes Based on Pyrimidine Ring Azo Schiff-Base Ligand: Synthesis, Characterization, Antioxidant, Antibacterial, and Thermal Investigations(Wiley-V C H Verlag Gmbh, 2014) Gulcan, Mehmet; Ozdemir, Sadin; Dundar, Abdurrahman; Ispir, Esin; Kurtoglu, MukerremSix transition metal(II) complexes with the heterocyclic ligand HL (1), [CuL2]center dot H2O (2), [NiL2]center dot 3H(2)O (3), [CoL2]center dot 3H(2)O (4), [MnL2]center dot 3H(2)O (5), [ZnL2]center dot 2H(2)O (6), [PdLOAc]center dot H2O (7) [HL = 5-benzoyl-1-((E)-(2-hydroxy-5-((E)-phenyldiazenyl)benzylidene)amino)-4-phenylpyrimidin-2(1H)-one] were synthesized. The features of the azo Schiff bases were assigned from microanalytical, spectroscopic (IR, UV/Vis., H-1- and C-13 NMR, API-ES mass), magnetic, and molar conductivity measurements at room temperature as well as thermal analysis. The electronic absorption spectroscopy and magnetic susceptibility measurements of the complexes indicate square pyramidal arrangement for Pd-II and octahedral environment for all the other complexes. The azo Schiff base HL acts as a monobasic tridentate ligand, which commonly coordinates through the oxygen atoms of the phenol OH and the pyrimidine one group, and the nitrogen atom of the azomethine group. The thermal behaviors of the ligand and its metal complexes were studied using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The metal complexes proved to be more thermally stable than the ligand; they decomposed at 10-30 degrees C higher temperatures. Antioxidant properties of the ligand and its metal complexes (DPPH free radical scavenging, ferrous chelating and reducing power activities) were tested. Antimicrobial activities were studied with gram-positive bacteria, which included Bacillus subtilis and Staphylococcus aureus, whereas Escherichia coli and Pseudomonas aeruginosa represented gram negative bacteria.Öğe Novel Cobalt(II), Zinc(II) Phthalocyanines Bearing Discrete Substituents: Synthesis, Characterization, Aggregation Behavior, Electrochemical Properties, and Antioxidant Activity(Taylor & Francis Inc, 2014) Agirtas, M. Salih; Cabir, Beyza; Dundar, Abdurrahman; Okumus, Veysi; Ceyhan, GokhanA new phthalonitrile derivative bearing 3,4,5-trimethoxy- benzyloxy and chloro-substituents at peripheral position was prepared by a nucleophilic displacement reaction. Cyclotetramerization of phthalonitrile derivative in dimethylsulfoxide (DMSO) gave the metallophthalocyanines. Novel Co(II), Zn(II) phthalocyanines (Pcs) were obtained from the reaction 4-[(3,4,5-trimethoxybenzyloxy]-5-chlorophthalonitrile and metal salts. The novel compounds have been characterized by using elemental analysis, UV-Vis, FTIR, H-1-NMR spectral data. The aggregation behaviors of Co(II), Zn(II) Pcs were also investigated. These metallophthalocyanines do not show any aggregation behavior between 1.2 x 10(-5) and 4.0 x 10(-6) M concentration range in DMF. The antioxidant activities of Pcs were investigated antioxidant assays such as free radical scavenging ability of 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and ferrous ion chelating ability. Furthermore, the redox properties of the Pcs complexes were investigated by using cyclic voltammetry.Öğe Pleurotus eryngii immobilized Amberlite XAD-16 as a abstract insert solid-phase biosorbent for preconcentrations of Cd2+ and Co2+ and their determination by ICP-OES (vol 99, pg 502, 2012)(Elsevier Science Bv, 2013) Ozdemir, Sadin; Okumus, Veysi; Kilinc, Ersin; Bilgetekin, Havin; Dundar, Abdurrahman; Ziyadanogullari, Berrin[Abstract Not Available]Öğe Preconcentration with Bacillus subtilis-Immobilized Amberlite XAD-16: Determination of Cu2+ and Ni2+ in River, Soil, and Vegetable Samples(Taylor & Francis Inc, 2015) Okumus, Veysi; Ozdemir, Sadin; Kilinc, Ersin; Dundar, Abdurrahman; Yuksel, Uyan; Baysal, ZubeydeSolid-phase extraction (SPE) method was developed for the preconcentration of Cu2+ and Ni2+ before their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). Bacillus subtilis-immobilized Amberlite XAD-16 was used as biosorbent. Effects of critical parameters such as pH, flow rate of samples, amount of Amberlite XAD-16 and biosorbent, sample volume, eluent type, and volume and concentration of eluent on column preconcentration of Cu2+ and Ni2+ were optimized. Applicability of the method was validated through the analysis of the certified reference tea sample (NCS ZC73014). Sensitivity of ICP-OES was improved by 36.4-fold for Cu2+ and 38.0-fold for Ni2+ by SPE-ICP-OES method. Limit of quantitation (LOQ) was found to be 0.7 and 1.1ng/ml for Cu2+ and Ni2+, respectively. Concentrations of Cu2+ and Ni2+ were determined by ICP-OES after application of developed method. Relative standard deviations (RSDs) were lower than 4.9% for Cu2+ and 7.9% for Ni2+. The Tigris River that irrigates a large agricultural part of Southeast Turkey is polluted by domestic and industrial wastes. Concentrations of Cu2+ and Ni2+ were determined in water, soil, and some edible vegetables as a biomonitor for heavy metal pollution.Öğe Production and characterization of thermostable ?-amylase from thermophilic Anoxybacillus flavithermus sp nov SO-19(Wiley-V C H Verlag Gmbh, 2016) Ozdemir, Sadin; Okumus, Veysi; Ulutas, Mehmet Sefa; Dundar, Abdurrahman; Akarsubasic, Alper Tunga; Dumontet, StefanoThis study was concerned with isolation and identification of thermophilic bacteria from hot spring in Afyonkarahisar (Gecek) and optimization of a-amylase production, partial purification of alpha-amylase, and characterization of extracellular enzyme from isolated thermophilic strain 19. To characterize and identify the thermophilic isolated bacteria, morphological analysis and biochemistry tests were studied. Besides, for classification 16S rRNA gene, G-C content and DNA-DNA hybridization analysis were performed. These results indicated that strain 19 is a novel species, Anoxybacillus flavithermus sp. nov. The effects of different fermentation conditions, such as incubation time, temperature, and pH, different carbon and nitrogen sources, and surfactants on a-amylase production were investigated. Various parameters such as temperature and temperature stability, pH and pH stability, detergents and surfactants, different starches, and metal ions on influence of enzyme characterization were assayed. About 93, 87, and 81% of the activities were retained after heating the partially purified enzyme solution at 50, 60, and 70 for 240 min, respectively. Enzyme was excessively inhibited by Hg2+ (6%). The enzyme was activated by Co2+ (212%) and Mg2+ (142%). Enzyme degradated 82% of starch content in apple juice at 70 degrees C in 30 min. The molecular weight of enzyme was estimated as 96 kDa.Öğe Selective preconcentration of Lanthanum(III) by Coriolus versicolor immobilised on Amberlite XAD-4 and its determination by ICP-OES(Taylor & Francis Ltd, 2014) Ozdemir, Sadin; Okumus, Veysi; Dundar, Abdurrahman; Celik, Kadir Serdar; Yuksel, Uyan; Kilinc, ErsinCoriolus versicolor, a wood fungus, was immobilised on Amberlite XAD-4 and used as solid-phase biosorbent for preconcentrations of rare earth elements. La(III), Th(IV), U(IV) and Ce(III) were subjected to solid-phase extraction procedure. We observed that La(III) was selectively preconcentrated, while other ions remained in solution at pH 6.0. 5.0mL of 1.0molL(-1) HCl was used to elaute La(III) from column. 250mg of C. versicolor loaded on 1000mg of XAD-4 was optimised as solid-phase matrix. Concentrations of ions in solutions were determined by inductively coupled plasma- optical emission spectrometry (ICP-OES). The calibration plot after preconcentration was linear in the range from 1.0 to 50.0ngmL(-1) for La(III). Limit of detection was found as 0.27ngmL(-1) for La(III) by SPE method. Relative standard deviation was found lower than 6.7% for 1.0ngmL(-1) of La(III) solution (n=10). The sensitivity of ICP-OES was improved by a factor of 46.8. The applicability of the method was validated through the analysis of certified reference samples of tea (NCS ZC-73014) and spinach (NCS ZC-73013).Öğe Solid Phase Extraction Based on the Use of Agaricus arvensis as a Fungal Biomass for the Peconcentrations of Pb and Al Prior to Their Determination in Vegetables by ICP-OES(Atomic Spectroscopy Press Ltd, 2013) Kilinc, Ersin; Dundar, Abdurrahman; Ozdemir, Sadin; Okumus, VeysiA solid phase extraction (SPE) method based on the use of a fungal biomass as sorbent was developed for the preconcentrations of Pb and Al. Agaricus arvensis was immobilized on Amberlite XAD-4 and loaded onto a column. Important parameters such as pH and flow rate of the solution, amount of biosorbent and resin, volume of sample solution, which affect the efficiency of the preconcentration procedure for Pb and Al, were optimized. The effect of possible interfering ions, i.e., Cd2+, Cu2+, Ni2+, Zn2+, Co2+, Na+, K+, Ca2+, Mg2+, and Fe2+, was investigated. Experiments on the repeatability of the solid phase column showed that the same column could be used at least 30 cycles without loss of the biosorption efficiency for the recovery of Pb and Al. The limit of detection (LOD) of Pb and Al was found to be 0.10 ng m(L-1) and 0.03 ng mL(-1), respectively. The sensitivity of ICP-OES improved 39.8-fold for Pb and 39.5-fold for Al. Linearity was obtained in the concentration range of 1.25-50.0 ng mL(-1) for Pb and 0.5-50.0 ng mL(-1) for Al. The relative standard deviation (RSD) of the method under optimum conditions was lower than 8.4% (n=5) for Pb and Al, which was validated through the analysis of certified reference tea and poplar leaves samples. The biosorption capacity of immobilized Agaricus arvensis for Pb and Al was found to be 31.2 mg g(-1) and 45.7 mg g(-1), respectively. The developed method was applied to determine the concentrations of Pb and Al in various edible vegetable samples (cucumber, okra, tomato, beans, aubergine, watermelon, zucchini, pepper, melon, lettuce, roka, purslane, scallion, cress, parsley, cabbage, sugar cane, and basil) grown along the cultivated banks of the Tigris River in Diyarbakir, Turkey.Öğe Synthesis and Characterization of a New Difunctional Ligand and Its Metal Complexes: An Experimental, Theoretical, Cyclic Voltammetric, and Antimicrobial Study(Taylor & Francis Inc, 2015) Baykara, Haci; Ilhan, Salih; Oztomsuk, Abdussamet; Seyitoglu, M. Salih; Levent, Abdulkadir; Okumus, Veysi; Dundar, AbdurrahmanA new difunctional Schiff base ligand and its some metal complexes were synthesized. The compounds were characterized by elemental analysis, H-1-NMR, C-13-NMR, FT-IR, UV-VIS, magnetic susceptibility measurements, molar conductivity measurements, and thermal gravimetric analysis techniques. Additionally, DPPH scavenging, metal chelating and antibacterial activity of compounds were examined via in vitro methods. The lowest DPPH scavenging activity observed by Co(II) as 36.28% and highest was ligand as 52.00%. A cyclic voltammetric study was also carried out to determine redox potentials of the compounds. Some theoretical studies such as H-1-NMR, HOMO-LUMO, and mapped electron density of the ligand were also carried out successfully.Öğe Synthesis and Characterization of Bionanomaterials and Evaluation of Their Antioxidant, Antibacterial, and DNA Cleavage Activities(Wiley-V C H Verlag Gmbh, 2021) Tarhan, Tuba; Dundar, Abdurrahman; Okumus, Veysi; Culha, MustafaIn this study, the hexagonal boron nitride (hBN) (1), poly-levodopa (P-L(DP) (2), P-L(DP) coated hBN (hBN@P(L-DP)) (3), and silver nanoparticles (AgNPs) decorated hBN@P(L-DP) (hBN@P(L-DP)-AgNPs) (4) were synthesized and characterized by multiple spectroscopic techniques. Additionally, their biological properties such as antioxidant, antibacterial, and DNA cleavage activities were determined. It is worth noting that, products 3 and 4 were newly synthesized structures. The antioxidant activities of all the nanomaterials 1, 2, 3, and 4 nanomaterials were investigated using some tests such as DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging and reducing power ability. Among the synthesized nanomaterials, product 2 exhibited the highest radical scavenging (64.8 +/- 1.94 %) and reducing power activity (0.61 +/- 0.017) at a concentration of 200 mg L-1. Product 4 was determined to have antibacterial activity against all three Gram-positive and three Gram-negative test bacteria. In addition, all the nanomaterials were tested for cleavage activity using pBR 322 plasmid DNA, as a result of which it was determined that only product 4 showed the ability of cleavage from both chains of DNA.Öğe SYNTHESIS, CHARACTERIZATION, AGGREGATION BEHAVIOR, ANTIOXIDANT ACTIVITY, AND ANTIBACTERIAL ACTIVITY OF METALLOPHTHALOCYANINES CARRYING FOUR PHTHALONITRILES GROUP(Editura Acad Romane, 2016) Guven, M. Emin; Agirtas, M. Salih; Ozdemir, Sadin; Dundar, AbdurrahmanA novel phthalonitrile derivative and zinc (II), cobalt (II), and cupper (II) phthalocyanines complexes were synthesis and characterized. The novel compounds have been characterized by using various spectroscopic data FTIR, UV/vis, NMR, elemental analysis etc. The aggregation investigations carried out in different concentrations indicate that 4- (4-(1-(4-phenoxypheny1)-1-phenylethyl)phenoxy)phthalonitrile substituted phthalocyanine compounds do not have any aggregation behavior for the concentration range of 10(-4)-10(-5) M in tetrahydrofuran. The antioxidant properties of the phthalonitrile and its phthalocyanine compounds were evaluated in three series of in vitro tests: DPPH free radical scavenging, ferrous ion chelating activity and reducing power. Antimicrobial activities of compounds were investigated.Öğe The Use of Fungal Biomass Agaricus bisporus Immobilized on Amberlite XAD-4 Resin for the Solid-Phase Preconcentration of Thorium(Taylor & Francis Inc, 2014) Ozdemir, Sadin; Okumus, Veysi; Dundar, Abdurrahman; Kilinc, ErsinSolid-phase extraction method was developed for the preconcentration of thorium (Th). Fungal biomass Agaricus bisporus was immobilized to Amberlite XAD-4 as solid-phase sorbent. The critical parameters such as pH of the sample solution, flow rate of the sample, volume of the sample, and the effect of major ions that affect the preconcentration of thorium in this system were evaluated. The optimum pH for the sorption of Th is 6.0, and quantitative elution occurs with 1.0mol L-1HCl. The loading capacity was determined as 0.079mmol g(-1). The optimized method was validated through analysis of the certified reference material of tea leaves (NCS ZC73014) and successfully applied to the determination of Th in a real ore sample with satisfactory results.
