https://hdl.handle.net/20.500.12809/32 2026-04-19T20:49:20Z 2026-04-19T20:49:20Z Casertano, Marcello Genovese, Massimo Santi, Alice Pranzini, Erica Balestri, Francesco Avunduk, Sibel https://hdl.handle.net/20.500.12809/10619 2023-03-27T10:38:29Z 2023-01-01T00:00:00Z

Evidence of Insulin-Sensitizing and Mimetic Activity of the Sesquiterpene Quinone Avarone, a Protein Tyrosine Phosphatase 1B and Aldose Reductase Dual Targeting Agent from the Marine Sponge Dysidea avara Casertano, Marcello; Genovese, Massimo; Santi, Alice; Pranzini, Erica; Balestri, Francesco; Avunduk, Sibel Type 2 diabetes mellitus (T2DM) is a complex disease characterized by impaired glucose homeostasis and serious long-term complications. First-line therapeutic options for T2DM treatment are monodrug therapies, often replaced by multidrug therapies to ensure that non-responding patients maintain target glycemia levels. The use of multitarget drugs instead of mono- or multidrug therapies has been emerging as a main strategy to treat multifactorial diseases, including T2DM. Therefore, modern drug discovery in its early stages aims to identify potential modulators for multiple targets; for this purpose, exploration of the chemical space of natural products represents a powerful tool. Our study demonstrates that avarone, a sesquiterpene quinone obtained from the sponge Dysidea avara, is capable of inhibiting in vitro PTP1B, the main negative regulator of the insulin receptor, while it improves insulin sensitivity, and mitochondria activity in C2C12 cells. We observe that when avarone is administered alone, it acts as an insulin-mimetic agent. In addition, we show that avarone acts as a tight binding inhibitor of aldose reductase (AKR1B1), the enzyme involved in the development of diabetic complications. Overall, avarone could be proposed as a novel natural hit to be developed as a multitarget drug for diabetes and its pathological complications.

2023-01-01T00:00:00Z Vai̇zoğullar, Ali İmran Topkara, Çağla Uğurlu, Mehmet https://hdl.handle.net/20.500.12809/10595 2023-03-15T12:11:42Z 2023-01-01T00:00:00Z

Ternary V-Scheme Ag2WO4/BaO/NiO Heterojunction Photocatalysts: Very Fast Degradation Process for Congo Red under UV-Light Irradiation Vai̇zoğullar, Ali İmran; Topkara, Çağla; Uğurlu, Mehmet With increasing industrial production, pollutants generated in the process of bleaching or dying disperse to the natural water medium. Therefore, an effective photocatalytic material must be prepared for water treatment quickly. In the present study, a novel and effective V-scheme Ag2WO4/BaO/NiO heterostructure photocatalyst with high photocatalytic performance for the degradation of different organic pollutants was designed and formed by a simple precipitation method. Scanning electron microscopy images showed that BaO, NiO, and Ag2WO4/BaO/NiO have a nanopipe, spherical, and nanorod morphology, respectively. X-ray diffraction results indicated that cubic phases were obtained with higher crystallite structure and lower crystallite distortion. The optical properties of the samples exhibited UV-absorption regions with about 3.35, 3.38, and 3.28 eV band gaps for BaO, BaO/NiO, and Ag2WO4/BaO/NiO, respectively. The photocatalytic activity was investigated by the degradation of Congo red under UV-light irradiation. To investigate the photocatalytic mechanism, the photodegradation performance of the catalyst was analyzed with different scavengers such as isopropyl alcohol, ascorbic acid, and potassium iodide (KI), and it was shown that the main active species were •O2- radicals and that OH• radicals have a significant contribution toward the degradation process. Compared to bare BaO and BaO/NiO samples, Ag2WO4/BaO/NiO showed excellent photocatalytic activity and about 41%, 66 and 99% of Congo red photodegraded under UV light within 30 min. The reason for this is that the Ag2WO4/BaO/NiO heterostructure displayed wider contact which promoted more charge-transfer ways to shorten the electron transportation path and increase the inhibition of electron-hole pairs.

2023-01-01T00:00:00Z Vaizoğulları, Ali İmran https://hdl.handle.net/20.500.12809/10518 2023-02-08T06:49:25Z 2023-01-01T00:00:00Z

Ag/La2O3/WO3 p–n heterojunction photocatalyst for clean environmental applications: degradation of oxytetracycline and H2 evaluation from formic acid Vaizoğulları, Ali İmran In the present study, the photocatalytic activities of nanocrystalline new silver-based (Ag) tungsten oxide (WO3) and lanthanum oxide (La2O3) materials prepared using the simple precipitation synthesis technique are studied. As a result of characterizations, the activity of the materials in both photocatalytic hydrogen production and oxytetracycline degradation was investigated. The characterizations of the synthesized materials were made by scanning electron microscope, X-ray diffraction, Raman, UV–diffuse reflectance spectroscopy (UV–DRS), electrochemical properties and X-ray photoelectron spectroscopy analyses. Morphological analyses showed that the materials were in a spherical and polygonal form, and the peaks of the characteristic components were obtained in the structural analysis. In addition, the structures of the materials were elucidated by Raman analysis supported with the X-ray diffraction results. The oxidation values of the components were obtained and compared the other characterization techniques. UV–DRS spectra analysis observed a redshift in the absorbing band edge and lower bandgap energy with 2.94 and 2.56 eV for La2O3 and WO3, respectively. In the hydrogen production reaction from formic acid, the Ag/La2O3/WO3 sample showed a higher production yield than the others. The obtained H2 production yield is 130, 140 and 230 µmol g−1 h−1 for Ag/WO3, Ag/La2O3 and Ag/La2O3/WO3, respectively. In addition, similar results were obtained in the degradation of oxytetracycline. The original part of this study presents a new perspective on which an effective photocatalytic study can be done with this; that can be easily synthesized Ag/La2O3/WO3 and can also play a role in hydrogen production. © 2023, The Author(s) under exclusive licence to Iranian Society of Environmentalists (IRSEN) and Science and Research Branch, Islamic Azad University.

2023-01-01T00:00:00Z Artagan, Öge Vaizoğulları, Ali İmran https://hdl.handle.net/20.500.12809/10215 2022-08-16T06:48:53Z 2022-01-01T00:00:00Z

A NOVEL AND EFFICIENT PHOTOCATALYSIS (ZnO/BENTONITE) FOR DISINFECTION OF Escherichia coli AND Pseudomonas aeruginosa UNDER VISIBLE LIGHT IRRADIATION Artagan, Öge; Vaizoğulları, Ali İmran n the present study, a new composite catalyst which highly active under the visible light was synthesized by immobilizing onto bentonite surface using ZnO materials (ZnO/Bent). For this, a simple in situ participant technique was used. The samples were characterized using SEM, XRD, BET techniques. SEM images possess that ZnO particles have nearly a spherical structure. Bentonite clay was used to increase the surface area of the samples. The obtained BET surface area of the samples shows that the ZnO/Bent catalyst was lower than that of pure Bentonite. The aim of this study was to evaluate the effectiveness of photocatalytic disinfection with ZnO-Bent composite against Escherichia coli and Pseudomonas aeruginosa under visible light. The obtained results show that when E. coli strain was subjected to ZnO-Bent mediated photocatalytic disinfection under solar irradiation, more than 98 % disinfection of the targeted E. coli was achieved within 2 hours and also 100% of P. aeruginosa colonies were inactivated within 4 hours under solar irradiation. A Possible degradation mechanism for ZnO/Bent composite was proposed in this study.

2022-01-01T00:00:00Z