Browsing by Author "Ozok, Omruye"

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Design of 2-(4 Based Remarkable Organic Catalyst Towards Hydrazine Electrooxidation
(Elsevier Science Sa, 2021) Er, Omer Faruk; Ulas, Berdan; Ozok, Omruye; Kivrak, Arif; Kivrak, Hilal
Herein, 2-(4-(2-pentyllbenzo[ b]thiophen-3-yl)benzylidene)malononitrile (6B) is synthesized by using coupling reactions, electrophilic cyclization reactions, and condensation reactions. Then, these materials are employed as anode catalysts for hydrazine electrooxidation reactions with electrochemical methods such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in 1 M KOH + 0.5 M N2H4 solution on different benzothiophene derivates. 6B catalyst exhibits the best catalytic activity in hydrazine electrooxidation reaction with 3.22 mA cm(-2) (16.72 mA mg(-1) 6B) value. Thus, for the electrodes obtained from 6B, the electrode preparation stage is optimized by the response surface methodology (RSM) and the hydrazine electrooxidation current under optimum conditions is found as 4.95 mA cm(-2). EIS results reveal that 6B modified electrode has the lowest charge transfer resistance. In conclusion, 6B catalyst could be used as anode catalysts in hydrazine fuel cells instead of expensive catalysts such as Pt, Pd, and Au.
Design, Synthesis and Pharmacological Evaluation of Novel Artemisinin-Thymol
(Taylor & Francis Ltd, 2022) Kavak, Emrah; Mutlu, Dogukan; Ozok, Omruye; Arslan, Sevki; Kivrak, Arif
A molecular hybridization of natural products is a new concept in drug discovery and having critical roles to design new molecules with improved biological properties. Hybrid molecules display higher biological activities when compared to the parent drugs. In the present study, two natural products (thymol and artemisinin (ART)) are used for the synthesis of new hybrid thymol-artemisinin. After characterization, the cytotoxic activity of ART-thymol was tested against different cancer cell lines and non-cancerous human cell line. ART-Thymol show the cytotoxic effect with EC50 values 70,96 mu M for HepG2, 97,31 mu M for LnCap, 6,03 mu M for Caco-2, 77,98 mu M for HeLa and 62,28 mu M for HEK293 cells, respectively. Moreover, ART-Thymol was checked for drug-likeness, and the kinase inhibitory activity. ART-Thymol is investigated by using molecular docking. The results of qPCR was indicated CDK2 and P38 were inhibited by ART-Thymol. These results improved that thymol-artemisinin may be new candidates as an anticancer agents. [GRAPHICS] .
Novel 5-(2 [B] Thiophen-3 Based Ovarian Cancer Carbohydrate Antigen 125 Electrochemical Sensor
(Elsevier Science Sa, 2022) Er, Omer Faruk; Kivrak, Hilal; Ozok, Omruye; Kivrak, Arif
Herein, an electrochemical sensor based 5-(2-phenylbenzo [b] thiophen-3-yl)furan-2-carbaldehyde (PTFC) was developed for the detection of cancer antigen 125 (CA125). Measurements were obtained via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV), and square wave voltammetry (SWV) techniques to investigate features of the electrochemical sensor such as concentration effect of CA125, incubation time, scan rate, limit of quantification (LOQ), limit of detection (LOD), and interference effect of structures found in serum. The sensor was found to have a fairly wide linear range as 0.01-100 ng mL(-1) and 100-1000 ng mL(-1). LOQ and LOD values were determined as 0.024015 ng mL(-1) and 0.008005 ng mL(-1) (S/N = 3), respectively. These results showed that the PTFC-based electrode could be a promising electrode for the detection of CA125.
Novel Benzothiophene Based Catalyst With Enhanced Activity for Glucose Electrooxidation
(Pergamon-elsevier Science Ltd, 2020) Ozok, Omruye; Kavak, Emrah; Er, Omer Faruk; Kivrak, Hilal; Kivrak, Arif
Thiophene based heterocyclic compounds plays important roles in organic chemistry due to their unexpected properties. Herein, novel benzothiophene derivatives (6A-F) are synthesized via Sonogashira coupling, iodocyclization reaction, Suzuki-Miyaura coupling and condensation reactions. After characterization of design molecules, their glucose electrooxidation activities are investigated. Electrochemical measurements are performed by cyclic voltammetry, chrono amperometry, and electrochemical impedance spectroscopy in 1 M KOH +0.5 M C6H12O6 solution. This results show that the highest performance organic-based catalysts is obtained as 0.729 mA/cm(2) (3.345 mA/mg) for the 2-(4-(2-pentylbenzo [b] thiophen-3-yl)benzylidene)malononitrile (6B). Furthermore, 6B catalyst is shown long term stability, the best current density value (1.151 mA cm(-2)), and the best transfer resistance load between organic-based catalysts. As a result, it is clear that these benzothiophene derivatives are promising organic based catalyst, an alternative to the expensive Pd and Pt based metal catalyst, for direct glucose fuel cell anode. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
A Novel Electrochemical Sensor for Monitoring Ovarian Cancer Tumor Protein Ca 125 on Benzothiophene Derivative Based Electrodes
(Elsevier Science Sa, 2022) Er, Omer Faruk; Kivrak, Hilal; Ozok, Omruye; Celik, Sebahattin; Kivrak, Arif
COVID-19 crisis affects ovarium cancer patients seriously. Thus, it is vital to diagnose ovarium cancer, one of the most common types of cancer diagnosed and the causes of death of women around the world, at early stages. Herein, 5-(2-phenylbenzo[b]thiophen-3-yl) thiophene-2-carbaldehyde (PTTC)-based sensor is designed to detect CA-125 more precisely and rapidly via electrochemical methods. PTTC, novel benzothiophene derivative, is synthesized by electrophilic cyclization reactions and Pd-catalyst coupling reactions. Then, PTTC is dispersed homogeneously in Nafion solution, and an ink is obtained. This ink is transferred onto the glassy carbon electrode and CA-125 is incubated on this electrode. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy measurements are employed to determine sensitivity and reliability of CA-125 on PTTC based GCE electrode. The effect of CA 125 concentration, incubation time, scan rate studies are performed by CV to determine the optimum conditions. Optimum conditions are found as 3 mu L PTTC loading, 5000 ng/mL CA125 antigen concentration and 30 min incubation time. Linear range of the PTTC based GCE electrode prepared at optimum conditions are obtained by DPV as 1-100 ng/ml.Limit of detection and limit of quantification values were obtained as 0.0096 ng/mL and 0.0288 ng/mL, respectively. Interference and artificial serum results reveal that this electrode is a promising electrode for CA125 antigen determination for the ovarium cancer. PTTC is a novel and unique material for the detection of ovarium cancer antigen CA-125 and promising for CA-125 antigen detection.
Synthesis and Characterization of 4-(2 Thiophen-3 for Carbohydrate Antigen 125 Electrochemical Detection and Molecular Docking Modeling
(Elsevier Science Sa, 2022) Kivrak, Hilal; Er, Omer Faruk; Ozok, Omruye; Celik, Sebahattin; Kivrak, Arif
4-(2-(4-methoxyphenyl)benzo[b]thiophen-3-yl)benzaldehyde (MPBB)-based chemical antibody is developed to detect CA125 (MUC-16) level more effectively via electrochemical methods. Novel MPBB is synthesized by using Pd-catalyst coupling reactions and electrophilic cyclization reactions. New benzothiophene structure is dispersed in Nafion solution and CA125 antigen was incubated on this electrode. Optimum conditions are found as 3 mu L MPBB loading, 30 ng/mL CA125 antigen concentration, and 90 min incubation time. Two distinct linear ranges of the electrode prepared at optimum conditions are determined by DPV as 5-50 ng/ml and 100-500 ng/ml. Limit of detection and limit of quantification values have been obtained as 0.03385 ng/mL and 0.10155 ng/mL, respectively. Interference and artificial serum results reveal that this electrode is a promising electrode for CA125 antigen determination for ovarian cancer. Binding energy is investigated by employing a molecular docking modeling study between CA125 antigen and MPBB. Electrochemical results and molecular docking results revealed that the MPBB is a promising alternative to marketed CA125 immunoassays.
Synthesis of Novel Artesunate-Benzothiophene and Artemisinin-Benzothiophene Derivatives
(Taylor & Francis Ltd, 2022) Ozok, Omruye; Kavak, Emrah; Kivrak, Arif
Natural products are used for the treatment of a variety of diseases for many years. Last decades, design and synthesis of novel biologically active hybrid molecules including natural product is gained big importance due to their unique and new biological properties. In the present study, novel artemisinin-benzothiophene derivatives (12 A-F) are synthesised. Initially, benzothiophene derivatives (4 A-4F) are prepared via the Pd-catalyzed coupling reactions and iodocyclisation reactions. Then, Suzuki-Miyaura coupling reactions were used for the formation of intermediates 6 A-6F (between 64% and 91% yields). Finally, the Steglich esterification reaction between intermediate 6 and artesunate formed the artemisinin-benzothiophene hybrids (9 A-9F) in moderate to excellent yields under very mild reaction conditions. When intermediate 6 was reacted with dihydroartemisinin, product 12 A-12F was also obtained with high yields.