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Öğe Biological assays and theoretical density functional theory calculations of Rh(I), Ir(III), and Ru(II) complexes of chiral phosphinite ligand(Wiley, 2020) Rafikova, Khadichakhan; Binbay, Nil Ertekin; Meriç, Nermin; Kerimkulova, Aygül; Zazybin, Alexey; Binbay, Veysel; Okumuş, Veysi; Kayan, Cezmi; Işık, Uğur; Aydemir, Murat; 0000-0003-1010-9563; 0000-0002-2488-0378; 0000-0001-8028-2244; 0000-0002-6244-9327Four metal complexes, IL-OPPh2-Ru-p-cymene (3), IL-OPPh2-Ru-benzene (4), IL-OPPh2-Ir-Cp* (5), IL-OPPh2-Rh-COD (6), have been evaluated for in vitro antioxidant activity such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and reducing power activity. Maximum scavenging activity (71.43%) was obtained with IL-OPPh2-Ru-p-cymene, whereas IL-OPPh2-Rh-COD showed the highest reducing power ability. The complexes were also studied for their antimicrobial activity against three Gram-positive and three Gram-negative bacteria. In addition, DNA binding of the complexes was evaluated using calf thymus DNA. Both Ru(II) complexes exhibited good DNA-binding activity while the other complexes did not have any activity. Furthermore, ab initio quantum calculations of four complexes were also carried out using density functional theory to better understand their chemical behaviors.Öğe Biological assays, electrochemical behavior, and theoretical DFT calculations of Ru(II) complexes of chiral phosphinite based based on ?-amino alcohols: Transfer hyrogenation of ketones using a HCOOH/Et3N mixture(Elsevier B.V., 2024) Khadichakhan, Rafikova; Meriç, Nermin; Binbay, Nil Ertekin; Okumuş, Veysi; Sever, M. Şerif; Belyankova, Yelizaveta; Aydemir, MuratSynthesis of two phosphinite ligands based on β-amino alcohols, in high yields has been demonstrated. When we treated [Ru(arene)(μ-Cl)Cl]2 {arene:p-cymene,benzene} with chelating phosphinite ligands, we obtained neutral Ru(II)-complexes possessing the general formula [Ru(arene)phosphiniteCl2]. The structure of the ligands and complexes was confirmed using analytical and spectroscopic techniques. The quantum chemical calculations were carried out for the ruthenium complexes at the DFT/CAM-B3LYP level of theory in gas phase. The phosphinite complexes were subjected to cyclic voltammetry studies in order to determine the energies of HOMO and LUMO levels and to estimate their electrochemical and some electronic properties. Organic complex-based memory substrates were immobilized using TiO2-modified ITO electrodes, and the memory functions of phosphinite-based organic complexes were verified by chronoamperometry (CA) and open-circuit potential amperometry (OCPA). In the present study, the antioxidant potentials of ruthenium-based p-cymene and benzene complexes through DPPH radical scavenging, metal chelating, and reducing power activities were also determined. In addition, DNA binding abilities and antimicrobial activities of these complexes against pathogenic bacteria were studied. Finally, the ruthenium complex, (2S)-1-{[(2S)-2-[(diphenylphosphanyl)oxy]propyl][(1R)-1-phenylethyl]amino}propan-2-yldiphenyl phosphinitobis[dichloro(η6-benzene)ruthenium(II)] also catalyzed asymmetric transfer hydrogenation of acetophenone with high conversion (up to 99%) and good enantioselectivity (ee up to 89 %), in the existence of formic acid and triethylamine in dichloromethane medium under air atmosphere.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) Özdemir, Sadin; Bekler, Fatma Matpan; Okumuş, Veysi; Dündar, Abdurrahman; Kılınç, Ersin; 0000-0001-8253-9568; 0000-0001-7384-7358; 0000-0002-5505-2700; 0000-0002-7930-1054; 0000-0001-5223-9919In 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 Citrullus lanatus L. (karpuz) ve Cucumis melo L. (kavun) kabuğu kullanılarak katı-faz fermentasyon tekniği (SSF) ile topraktan izole edilen Bacillus sp.'den alkalin serin proteaz eldesi(2016) Okumuş, Veysi; Agüloğlu Fincan, SemaBu çalışmada Bacillus sp.'den SSF tekniğiyle alkalin serin proteaz üretimi araştırıldı. Bacillus sp.'nin hangi substratta daha iyi proteaz ürettiğini tespit etmek amacıyla karpuz kabuğu, kavun kabuğu, mercimek kabuğu, pirinç kabuğu ve dan kullanıldı. En yüksek enzim üretimi kavun kabuğunda 72 saatlik inkübasyon süresi sonunda görüldü. Enzim üretimi üzerine bazı karbon ve azot kaynaklarının etkisi çalışıldı. Ayrıca enzim aktivitesi üzerine pH, sıcaklık, deterjan, ve ağır metallerin etkisi incelendi. Yapılan inhibisyon çalışmasında PMSF ile inhibe olan enzimin Alkalin Serin Proteaz olduğu tespit edildi Anahtar kelimeler: Bacillus sp.; SSF; alkalin serin proteazÖğe Determination of cytotoxic, anticholinesterase, antioxidant and antimicrobial activities of some wild mushroom species(Informa Healthcare, 2016) Dündar, Abdurrahman; Okumuş, Veysi; Özdemir, Sadin; Çelik, Kadir Serdar; Boğa, Mehmet; Özçağlı, Eren; 0000-0002-5505-2700In 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.Öğe Diyarbakır karpuz genotiplerinin (Citrullus lanatus cv. `Beyazkış', `Karakış' ve `Sürme') mikroçoğaltılması üzerine biyoteknolojik araştırmalar(2016) Okumuş, Veysi; Başaran, DavutBu çalışmada bölgemizi istila eden yabancı hibrit tohumlar yüzünden yok olma tehlikesiyle karşı karşıya bulunan yerel Diyarbakır karpuz genotiplerinin (Citrullus lanatus cv. `Beyazkış', `Karakış' ve `Sürme') hızlı bir şekilde in vitro mikroçoğaltımı için uygun bir protokol geliştirmek ve bu karpuz genotiplerinden tetraploid hatlar elde edilmesi amaçlanmıştır. Mikroçoğaltım için kültüre alınacak olan tohumların yüzey sterilizasyonu, %4'lük NaOCl içinde `Karakış' ve `Sürme'de 10, `Beyazkış'ta 15 dakika boyunca çalkalanarak yapılmış ve tohumlar çimlenme için MS besiyerinde (Murashige and Skoog, 1962) kültüre alınmıştır. Diyarbakır karpuz tiplerinin 5 günlük in vitro fidelerinden, 3 haftalık kültür sonucu sürgün uçları elde edilmiştir. Sürgün proliferasyonu için test edilen sitokininler (BA, kinetin) içerisinde `Sürme' için 0.5 mgl-1; `Karakış' ve `Beyazkış' için 1.0 mgl-1 BA içeren, 7 gl-1 agar ve 30 gl-1 sakkaroz içeren, 1:1 konsantrasyonunda MS besi ortamının en iyi sonucu verdiği saptanmıştır. Ekonomik olarak en fazla öneme sahip olan `Sürme' tipinde sürgün proliferasyonuna, ayrıca beş farklı aminoasit (lösin, metiyonin, triptofan, valin, alanin) ve üç farklı poliaminin (spermin, spermidin, putresin) etkisi incelenmiştir. Çalışma sonucunda `Sürme' tipinde 100 ?M metiyonin ve 50 ?M spermini birlikte içeren besi ortamının sürgün veriminde çok etkili olduğu gözlenmiştir. İn vitro elde edilen sürgünlerin köklendirilme çalışmalarında test edilen oksinler (IBA, IAA ve NAA) içerisinde en iyi köklenmenin, her üç karpuz tipinde de 1.0 mgl-1 IBA içeren MS besiyerinde olduğu saptanmış ve bu ortamdaki sürgünlerden, `Beyazkış'ta % 76, `Karakış'ta % 91 ve `Sürme'de % 95 oranında köklenme elde edilmiştir. İn vitro köklendirilen sürgünler tarlaya başarılı bir şekilde aktarılmıştır. Mikroçoğaltılmış bitkilerden ve direkt tohumdan elde edilmiş karpuzlar ürün verimi ve şeker içeriği yönünden mukayese edilmiş, ancak önemli bir farklılık gözlenmemiştir. Tetraploid karpuz bitkisi elde etmek için hem in vivo hem de in vitro yöntemler denenmiştir. Ploidi seviyesi stoma bekçi hücrelerindeki kloroplastların sayılması ve taze yaprakta toplam DNA miktarının spektrofotometrik olarak tespit edilmesiyle belirlenmiştir. Çalışma sonuçlarına göre tetraploid bitki elde etmek için her üç karpuz tipinde de in vitro yöntemlerin daha iyi sonuç verdiği görülmüştür. Tohumun % 0.03 kolşisinli MS ortamında çimlenmesiyle poliploidi oranı `Sürme'de %27, `Karakış'ta % 23.5, `Beyazkış'ta ise %16.2 olarak gerçekleştirilmiştir. Anahtar kelimeler: Karpuz, in vitro, mikroçoğaltım ve tetraploidÖğe Half-sandwich ruthenium(II) and iridium(III) complexes of imidazole based phosphinite ligands: antioxidant and antibacterial activities as well as electrochemical properties(John Wiley and Sons Inc, 2024) Işık, Uğur; Rafikova, Khadichakhan; Meriç, Nermin; Güzel, Remziye; Kerimkulova, Aygül; Akimbek, Arailym; Okumuş, Veysi; Durap, Feyyaz; Kayan, Cezmi; Aydemir, MuratRuthenium(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(η6-benzene)ruthenium]diphenylphosphanyl}oxy)propyl)-1-butyl-1H-imidazol-3-ium chloride], 4 at 200 μg/mL concentration, while [3-(3-chloro-2-({[dichloro(η5-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.Öğe In vitro propagation of Diyarbakır watermelons and comparison of direct-seeded and transplanted watermelon(2011) Başaran, Davut; Pirinç, Vedat; Onay, Ahmet; Okumuş, VeysiSürgün ucu eksplantları kullanılarak Diyarbakır karpuz tipleri Sürme, Beyazkış ve Karakış’ın mikroçoğaltımı için hızlı bir protokol geliştirilmiştir. İn vitro koşullarda çimlendirilmiş 5 günlük fi delerin sürgün uçları 3 haft a süreyle sürgün rejenerasyon ortamında kültüre alınmıştır. Farklı konsantrasyonlardaki benzil adenin (BA) ve karbonhidrat tiplerinin sürgün proliferasyonuna etkileri test edilmiştir. Sonuçlar her 3 genotipte de 0,5-1,0 mg/L aralığındaki BA ortamında sürgün uzunluklarının hemen hemen eşit olduğunu göstermiş ve BA ortamına sukroz eklenmesiyle ortalama sürgün sayısı ve sürgün uzunluğunun diğer karbonhidratlara göre daha yüksek olduğu tespit edilmiştir. Her 3 genotip için en iyi köklenme ortamının 1.0 mg/L IBA olduğu belirlenmiş ve IBA’da köklendirilen sürgünler Beyazkış ve Karakış için % 85, Sürme için % 90 başarıyla steril komposta aktarılmıştır. Sürme genotipinde hem doğrudan tohumdan hem de aktarılmış fi delerden elde edilen ürün verimi ve ortalama meyve ağırlığı, Beyazkış ve Karakış’tan daha yüksek bulunmuştur. Temel çözünür şekerler HPLC (yüksek performanslı sıvı kromatografi ) ile kantitatif olarak tespit edilmiştir. Beyazkış’ta tohumdan elde edilen ve Karakış’ta aktarılmış fideden elde edilen karpuzda, en çok bulunan şeker fruktoz olarak tespit edilmiştir. Bu sonuçlarla yüksek kaliteli Diyarbakır karpuzunun in vitro çoğaltılabileceği gösterilmiştir.Öğe The obtainment of alkaline serine protease from Bacillus sp. isolated from solid through the solid-state fermentation technique by using rind of the citrullus lanatus L. (watermelon) and cucumis melo L. (melon)(Dicle Üniversitesi Ziya Gökalp Eğitim Fakültesi, 2007) Fincan, Sema Agüloğlu; Okumuş, VeysiBu çalışmada, ekonomik önemi olmayan ve birikerek çevre kirliliğine yol açan karpuz ve kavun kabuğu katı substrat olarak kullanılarak Katı-Faz Fermentasyonu (SSF) yöntemi ile Bacillus sp.’den yüksek miktarda alkalin serin proteaz eldesi amaçlandı. Enzim aktivitesi üzerine pH, sıcaklık, metaller, azot ve karbon kaynakları etkisi incelendi. Yapılan inhibisyon çalışmasında PMSF ile inhibe olan enzimin alkalin serin proteaz olduğu tespit edildi. SSF yöntemi ekstrasellular enzimlerin düşük masrafla, hızlı bir şekilde, bol miktarda ve çevreye zarar vermeden üretilebildiği bir yöntem olduğu için kullanıldı.Öğe Synthesis of cis-1,2-diol-type chiral ligands and their dioxaborinane derivatives: Application for the asymmetric transfer hydrogenation of various ketones and biological evaluation(Wiley, 2020) Kılıç, Ahmet; Balcı, Tuğba Ersayan; Arslan, Nevin; Aydemir, Murat; Durap, Feyyaz; Okumuş, Veysi; Tekin, Recep; 0000-0001-9073-4339; 0000-0003-0899-1948; 0000-0002-4238-5012; 0000-0003-0142-9215; 0000-0002-5505-2700; 0000-0003-4577-4475Two cis-1,2-diol-type chiral ligands (T-1 and T-2) and their tri-coordinated chiral dioxaborinane (T(1-2)B(1-2)) and four-coordinated chiral dioxaborinane adducts with 4-tert-butyl pyridine sustained by N -> B dative bonds (T(1-2)B(1-2)-N) were synthesized and characterized by various spectroscopic techniques such as NMR (H-1, C-13, and B-11), FT-IR and UV-Vis spectroscopy, LC-MS/MS, and elemental analysis. It was suggested that both ferrocene and trifluoromethyl groups played key roles in the catalytic and biological studies because they could tune the solubility of the chiral dioxaborinane complexes and adjust the strength of intermolecular interactions. To assess the biological activities of newly synthesized chiral dioxaborinane compounds, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, reducing power, antibacterial, DNA binding, and DNA cleavage activities were tested. Then, all chiral dioxaborinane complexes were investigated as catalysts for the asymmetric transfer hydrogenation of various ketones under suitable conditions. The results indicated that the chiral dioxaborinane catalysts performed well with high yields.Öğe Well designed iridium-phosphinite complexes: Biological assays, electrochemical behavior and density functional theory calculations(Elsevier B.V., 2024) Khadichakhan Rafikova; Meriç, Nermin; Binbay, Nil Ertekin; Okumuş, Veysi; Erdem, Kemal; Belyankova, Yelizaveta; Güzel, RemziyeMononuclear phosphinite Iridium complexes based on ferrocene group have been prepared and characterized by various spectroscopic techniques. The complexes were subjected to cyclic voltammetry studies in order to determine the energies of HOMO and LUMO levels and to estimate their electrochemical and some electronic properties. Organic complex-based memory substrates were immobilized using TiO2-modified ITO electrodes, and the memory functions of phosphinite-based organic complexes were verified by chronoamperometry (CA) and open-circuit potential amperometry (OCPA). Extensive theoretical and experimental investigations were directed to gain a more profound understanding of the chemical descriptors and the diverse electronic transitions taking place within the iridium complexes, as well as their electrochemical characteristics. The quantum chemical calculations were carried out for the iridium complexes at the DFT/CAM-B3LYP level of theory in the gas phase. Furthermore, the antioxidant, antimicrobial, DNA binding, and DNA cleavage activities of the complexes were tested. Complex 2 exhibited the highest radical scavenging activity (67.5 ± 2.24 %) at 200.0 mg/L concentration. It was observed that the complexes formed an inhibition zone in the range of 8–15 mm against Gram + bacteria and in the range of 0–13 mm against Gram – bacteria. The agarose gel electrophoresis method was used to determine the DNA binding and DNA cleavage activities of the complexes. All of the tested complexes had DNA binding activity; however, complexes 1, 2, and 8 showed better binding activity than the others.
