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Öğe Advanced-designed Ru(II) complexes containing phosphinite ligands derived from chiral amino alcohols: Electrochemical behavior, DFT calculations, and biological activity(Elsevier Science Sa, 2025) Meric, Nermin; Isik, Ugur; Dauletbakov, Anuar; Zolotareva, Darya; Zazybin, Alexey; Sever, Mehmet Serif; Okumus, VeysiWe report two phosphinite ligands derived from chiral amino alcohols, and their complexes with ruthenium(II). These compounds were characterized by spectroscopic methods. Then, antimicrobial, antioxidant, and DNA binding activities of the chiral Ru(II)-phosphinite complexes were tested. Complex (1R)-2-{benzyl[(1S)-1(naphthalen-1-yl)ethyl]amino}-1-phenylethyl diphenylphos- phinito[dichloro(eta 6-p-cymene)ruthenium(II)], 7 showed both the highest radical scavenging activity (90.93 +/- 0.98 %) and the highest metal chelating activity (65.45 +/- 1.46 %) at 200.0 mg l-1 concentration. In addition, all of complexes had different rates of binding activity to calf thymus DNA (CT-DNA). Moreover, extensive theoretical and experimental investigations were conducted to gain a more profound understanding of the chemical descriptors and the diverse electronic transitions taking place within the ruthenium complexes, as well as their electrochemical characteristics.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 Half-sandwich ruthenium(II) and iridium(III) complexes of imidazole based phosphinite ligands: antioxidant and antibacterial activities as well as electrochemical properties(Wiley-V C H Verlag Gmbh, 2024) Isik, Ugur; Rafikova, Khadichakhan; Meric, Nermin; Guzel, Remziye; Kerimkulova, Aygul; Akimbek, Arailym; Okumus, VeysiRuthenium(II) and iridium(III) complexes of phosphinites including imidazole moiety were synthesized and characterized by microanalysis, IR, MS, and NMR spectroscopies. Antibacterial activity against Gram-positive and Gram-negative bacterial strains was assessed in all complexes. The highest radical scavenging (72.2 %) was obtained for [3-(3-chloro-2-({[dichloro(eta 6-benzene)ruthenium]diphenylphosphanyl}oxy)propyl)-1-butyl-1H-imidazol-3-ium chloride], 4 at 200 mu g/mL concentration, while [3-(3-chloro-2-({[dichloro(eta 5-pentamethylcyclopentadienyl)-iridium]diphenylphosphanyl}oxy)pro-pyl)-1-butyl-1H-imidazol-3-ium chloride], 6 demonstrated the highest antibacterial activity as 13 mm inhibition zone against E. hirea. Furthermore, optical and electrochemical featured of metal complexes containing imidazole phosphinite were investigated utilizing UV-vis absorption and cyclic voltammetry techniques. Consequently, all complexes can be proposed as metal-based charge convertible phosphinite complexes which may be employed as new generation and synergistic Dye-Sensitized Solar Cell (DSSC) materials. Ruthenium(II) and iridium(III) complexes of phosphinites including imidazole moiety are synthesized and characterized by microanalysis, IR, MS, and NMR spectroscopies. Their antibacterial activity against Gram-positive and Gram-negative bacterial strains is assessed. Furthermore, optical and electrochemical features of the metal complexes are investigated utilizing UV-vis absorption and cyclic voltammetry techniques. imageÖğe In vitro propagation of Diyarbakir watermelons and comparison of direct-seeded and transplanted watermelon(Tubitak Scientific & Technological Research Council Turkey, 2011) Okumus, Veysi; Pirinc, Vedat; Onay, Ahmet; Basaran, DavutA rapid protocol using shoot tip explants for micropropagation of Diyarbakir watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] types Surme, Beyazkis and Karakis was achieved. Shoot tips from 5-day-old in vitro germinated seedlings were cultured on shoot regeneration medium for 3 weeks. The effects of the different concentrations of benzyl adenine (BA) and carbohydrate types on shoot proliferation were examined. The results confirmed that a range of 0.5-1.0 mg/L of BA was almost equally effective in promoting the shoot length of cultures in the 3 genotypes. Sucrose, in the presence of BA, was superior to other carbohydrates for the 3 genotypes studied in terms of the number of proliferated shoots and the average shoot length obtained. The highest percentage of rooting was achieved when medium supplemented with 1.0 mg/L of indole-3-butyric acid (IBA) was used for the 3 genotypes. The highest frequency of acclimatized plantlets for the 3 genotypes was 85%, 85%, and 90%, respectively, in sterile compost, when the shoots of Beyazkis, Karakis, and Surme were rooted in the IBA-supplemented rooting treatments. The Surme genotype produced a significantly higher yield and mean fruit weight than the Beyazkis and Karakis genotypes in both direct-seeded and transplanted watermelons. The main soluble sugar of the experimental types was separated, identified, and quantified using high performance liquid chromatography (H PLC). Fructose was found to be the most abundant sugar and was highly detected in Beyazkis for the seeded watermelon and in Karakis for the transplanted watermelon. This demonstrates that in vitro propagation can be used to produce high quality diploid Diyarbakir watermelon for use in breeding lines.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 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 Pleurotus eryngii immobilized Amberlite XAD-16 as a solid-phase biosorbent for preconcentrations of Cd2+ and Co2+ and their determination by ICP-OES(Elsevier Science Bv, 2012) Ozdemir, Sadin; Okumus, Veysi; Kilinc, Ersin; Bilgetekin, Havin; Dundar, Abdurrahman; Ziyadanogullari, BerrinThis article reports a method that is used for the preconcentration and determination of Cd2+ and Co2+ in vegetables, using Pleurotus eryngii immobilized Amberlite XAD-16 as a solid-phase biosorbent. The concentrations of metals were determined by inductively coupled plasma-optical spectrometry (ICP-OES). Critical parameters, such as the pH of the solution, flow rate, the amount of biosorbent, type and volume of eluent, and the sample volume, that affect the solid-phase extraction (SPE) procedure were optimized. The optimum extraction conditions were determined as being a pH of 6.0 for Cd2+ and of 5.0 for Co2+; a sample flow rate of 2.0 mL min(-1); 200.0 mg of biosorbent; and 5.0 mL of 1.0 mol L-1 HCl as eluent. The capacities of the biosorbent for metal uptake were found to be 11.3 and 9.8 mg g(-1) for Cd2+ and Co2+ ions, respectively. Limit of quantitations (LOQs) were found to be 0.67 and 0.82 ng mL(-1), respectively, for Cd2+ and Co2+. The linear working curves were observed to be in the linear range from 1.0 to 50.0 ng mL(-1), and possessed high correlation coefficients. The use of the SPE method showed 50.7- and 35.7-fold improvements in the sensitivities of ICP-OES. The developed method was successfully applied to NCS ZC-73014 (a certified reference tea sample). Relative standard deviations (RSD) were lower than 5.0%. The Cd2+ and Co2+ concentrations in the different parts (leave, root, stem, and fruit) of purslane, onion, rocket, okra, and aubergine were determined after microwave digestion and solid-phase extraction by P. eryngii immobilized on Amberlite XAD-16. (C) 2012 Elsevier BM. All rights reserved.Öğe Preconcentration of metal ions using microbacteria(Springer Wien, 2013) Ozdemir, Sadin; Okumus, Veysi; Dundar, Abdurrahman; Kilinc, ErsinThis review (160 refs). covers the current state of the art of microbacteria-based sorbents for preconcentration of metal ions at trace levels. We highlight advantages and major challenges of the techniques and discuss future perspectives of both batch and column-based methods. Particular attention is paid to the preconcentration of metal ions using resin-immobilized microbacteria for solid phase extractions. We also discuss detection methods including UV-vis spectrophotometry, FAAS, ICP-OES and ICP-MS. Analytical figures of merit are compared, and examples are given for the application to a variety of samples including food, beverages, alloys, water, soil, and geological samples.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 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 Simultaneous High-Performance Thin-Layer Chromatographic Determination of Indole Acetic Acid, Indole Butyric Acid, and Absisic Acid in in vitro Seedling of Watermelon Exposed to Heavy Metals(Springer Heidelberg, 2012) Kilinc, Ersin; Okumus, Veysi; Duz, M. Zahir; Aydin, FiratA new method based on the use of high-performance thin-layer chromatography (HPTLC) was developed for the simultaneous determination of the plant growth hormones, indole acetic acid, indole butyric acid, and absisic acid in in vitro seedling of watermelon. The measurements were performed at the associate maximum absorption wavelength of hormones. Calibration plots were constructed in the range of 50-600 ng per spot for indole acetic acid, 50-600 ng per spot for indole butyric acid, and 50-600 ng per spot for absisic acid. The limits of quantification (LOQs) determined experimentally were as follows: 10, 10, and 6 ng per spot, respectively, for indole acetic acid, indole butyric acid, and absisic acid. The method was successfully applied to watermelon tissues exposed to Cu2+, Co2+, and Pb2+ for determination of its indole acetic acid, indole butyric acid, and absisic acid concentrations.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 of ionic liquid-based Ru(II)-phosphinite complexes and evaluation of their antioxidant, antibacterial, DNA-binding, and DNA cleavage activities(Springer International Publishing Ag, 2019) Meric, Nermin; Kayan, Cezmi; Rafikova, Khadichakhan; Zazybin, Alexey; Okumus, Veysi; Aydemir, Murat; Durap, FeyyazTwo Ru(II) complexes were synthesized by reaction of phosphinite-functionalized imidazolium salts [(Ph2PO)C7H11N2Cl]Cl (1) and [(Cy2PO)C7H11N2Cl]Cl (2) with 1/2 equivalent of [Ru(eta(6)-p-cymene)(mu-Cl)Cl](2) in anhydrous CH2Cl2 and under argon atmosphere. The complexes were then isolated as analytically pure substances and characterized using multinuclear NMR and infrared spectroscopies and elemental analysis. The Ru(II) compounds were used to study their biological assay. For this purpose, radical scavenging, reducing power, antibacterial activity, DNA binding, and DNA cleavage activity were fully studied. The maximum 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH) scavenging (78.9%) and reducing power were obtained from compound 4 at the concentration of 200 mu g/ml. The compounds were also tested against three Gram-positive and three Gram-negative bacteria, and they were found to be more effective against Gram-positive bacteria. In addition, both compounds showed excellent DNA binding and DNA cleavage activity.Öğe Transition metals of arene derivatives with functionalized ionic liquid: DFT investigation, biological applications and electrochemical behavior of complexes(Elsevier Science Sa, 2022) Rafikova, Khadichakhan; Meric, Nermin; Guzel, Remziye; Arslan, Nevin; Binbay, Nil Ertekin; Kayan, Cezmi; Okumus, VeysiMononuclear transition metal complexes based on ionic liquid have been prepared and characterized in detail. The biological properties of the three complexes were evaluated using radical scavenging activity, reducing power, antibacterial effect, DNA binding and cleavage activity. Among the complexes, [3-[(2R)-2-({[dichloro(eta(6)-benzene)ruthenium]diphenylphosphanyl}oxy)-2-phenylethyl]-1-methyl-1H-imidazol-3-ium chloride] (4), demonstrated the highest radical scavenging (64.7 %) and reducing power activity (0.467) at 200 mu g/ml concentration. The highest zone of inhibition was obtained from [3-[(2R)-2-({[dichloro(eta(6)-p-cymene)ruthenium]diphenyl phosphanyl}oxy)-2-phenylethyl]-1-methyl-1H-imidazol-3-ium chloride] (3), against Bacillus cereus as 14 mm. Furthermore, all complexes were determined to have DNA binding and cleavage activities. Furthermore, theoretical DFT computations have also been carried out for the cationic complexes, to obtain minimum energy configuration of molecules. The effects of the chemical structures of three cationic complexes were also examined in relation to the variable property of electron-donating ligands for ruthenium-based complexes and iridium complex and their potential energy levels in ground and excited states HOMO and LUMO were determined.
