Kadir Turhan

This study focuses on the synthesis of two new bisphenol-based polyimide (PI) sizing agents to improve the fiber–matrix interface of carbon fiber-reinforced poly (ether ether ketone) (CF/PEEK) composites. One of the synthesized polyimides contains bisphenol A (BPA) monomer, while the other has bisphenol S (BPS) monomer. The produced polyimide precursor resins were coated with carbon fibers by thermal imidization. The thermal, thermomechanical, and mechanical properties of the CF/PEEK composites produced by the autoclave process were investigated. According to the mechanical test results, there was a balanced performance between the BPS-containing polyimide-coated composites (CF-PEEK-PI-S) and the BPA-containing polyimide-coated composites (CF-PEEK-PI-A). While tensile strength is 291 MPa and interlaminar shear (ILSS) strength is 119 MPa, the CF-PEEK-PI-A sample showed superior mechanical properties in flexural (92.1 MPa) and compressive strength (54.9 MPa). As a result, it was concluded that bisphenol-based polyimide coatings significantly improve the interfacial interactions in CF/PEEK composites, which have great potential in aerospace, automotive and advanced engineering applications.

. In this study, firstly, benzylidene derivatives were obtained by Knoevenagel condensation using various aryl aldehydes and malononitrile in the presence of ethanol and then these differently substituted benzylidene compounds were substituted with 5-amino-3-methyl-1-phenylpyrazole and 6-amino-1-amino-1-phenylpyrazole, respectively, 3-dimethyluracil and ytterbium(III) trifluoromethane-sulfonate [Yb(OTf)3] or acetic acid catalyzed pyrazolo[3,4-b]pyridine and pyrido[2,3-d]pyrimidine derivatives were synthesized (5a-5i), and the structures of these compounds, which were purified by different methods, were elucidated by spectroscopic methods such as FTIR, 1H-NMR, 13C-NMR and GS-MS. In our study, compounds 3a, 5a and 5c were synthesized for the first time. In addition, Yb(OTf)3, one of the metal catalysts considered environmentally friendly catalysts, was used in this research. The genotoxic and antigenotoxic properties of the synthesized compounds were investigated in vitro using Ames Salmonella/microsome mutagenicity assay in the concentration range of 0.2-1.0 mM/plate. The results revealed that none of the compounds were mutagenic on three different Salmonella typhimurium strains up to the highest tested concentration. Moreover, in our study, 5a, 5e, 5f and 5h showed significant antigenotoxic effects ranging from moderate to strong against mutagen-induced DNA damage at relatively higher doses. KEY WORDS: Prido[2,3-d]pyrimidine, Pyrazolo[3,4-b]pyridine, Heterocyclic compounds, Benzylidene derivatives Bull. Chem. Soc. Ethiop. 2025, 39(6), 1201-1212. DOI: https://dx.doi.org/10.4314/bcse.v39i6.14

Nuclear applications are being increasingly used in various fields, necessitating studies to protect from radiation hazards and their effects. In this study, five different chemical structures of pyrazolo [3,4-b] pyridine derivatives were synthesized. The gamma and neutron radiation protective abilities of these samples were determined and demonstrated their potential use as ingredients in radioprotective drugs. Gamma radiation absorption parameters were calculated both theoretical and experimental. Important attenuation parameters for fast neutrons (4.5 MeV energy radiation) were figured out using the Monte Carlo simulation Geant4 code. Additionally, experimental dose rates were measured for each sample and compared to those of Paraffin and high-density polyethylene, an organic substance. Besides, Ames/Salmonella test system was aimed to detecting genotoxicity features of pyrazolo pyridine derivatives. All results demonstrated that each sample possesses both gamma and neutron radiation attenuation capabilities. It was determined that sample PPC4 (C₂₀H₁₄BrN₅) exhibited the highest gamma radiation attenuation capacity among all samples, while sample PPC2 (C₂₂H₂₀N₆) displayed an excellent neutron stopping capacity. The genotoxic properties of pyrazolo[3,4-b] pyridine derivatives were examined using the Ames/Salmonella test, and as a result, it was determined that these substances did not exhibit genotoxic effects at test doses up to 5 mM. All obtained results indicate that all PPC (pyrazolo[3,4-b] pyridine derivatives) samples do not possess a toxic effect, and they can be utilized as an active substance for the development of a drug or cream with protective properties against both gamma and neutron radiations.

Heterocyclic compounds are found in a variety of drug molecules, and bioactive natural products. 4‐Thiazolidinones (4‐TZDs), which represent an important class of heterocyclic compounds, are of great interest today with their diverse bioactivities. In this study, ten novel 4‐TZD derivatives (C1–C10) were synthesized, characterized by spectroscopic techniques, and their genotoxic, and antigenotoxic properties were investigated in vitro using the Ames Salmonella/microsome mutagenicity assay in the concentration range of 0.2–1.0 mM/plate. The results revealed that none of the compounds were mutagenic on the three different Salmonella typhimurium strains up to the highest concentration tested. Furthermore, in our study, C1, C4, C6, and C9 showed significant, ranging from moderate to strong, antigenotoxic effects against mutagen‐induced DNA damage at relatively higher doses. Among these, C4 had the best potential to inhibit the number of revertant colonies induced by 9‐aminoacridine (9‐AA), with a maximum inhibition rate of 47.9 % for 1.0 mM/plate. As a result, preliminary knowledge about the safety of the use of ten novel synthesized 4‐TZD compounds likely to exhibit many bioactivities was obtained in this study. In addition, the significant in vitro antimutagenic activity of some derivatives increases the importance of studies for the development of new pharmacological agents for cancer prevention.

Five different types of synthesized azadispiro derivatives have been analysed for radiation absorption capacity and determined their potential to be exploited as substances for a drug be developed ...

Purpose: Quinoline is formed by various natural compounds, such as alkaloids from the cinchona plant, which exhibit various biological activities, and is an important building material for the development of new drugs. Quinoline can be used in anti-radiation drug development but radiation interaction properties must be determined. Material and Methods: In this study, six types of synthesized quinoline derivatives were used. Fast neutron removal cross-section, mean free path, half value layer and transmission number were theoretically determined by using GEometry ANd Tracking 4 and FLUktuierende KAskade simulation codes for neutron shielding. Neutron dose absorption rates were determined using the ²⁴¹Am-Be fast neutron source and the Canberra NP series portable BF₃ gas proportional neutron detector. Gamma radiation shielding parameters were determined by using WinXCom and PSY-X/PSD software. Additionally, the genotoxic potentials of the derivatives were assessed by using the Ames/Salmonella bacterial reversion assay. Results and Conclusions: Neutron shielding parameters such as removal cross-section, mean free path, half value layer and transmission number were theoretically determined for fast neutrons. To determine neutron absorption capacity of quinoline derivatives, neutron absorption, experiments were conducted. In addition, gamma radiation shielding parameters were calculated such as the mean free path (MFP), mass attenuation coefficient (μt), half value thickness layer (HVL) and effective atomic number (Zeff) in the energy range of 0.015–15 MeV. The results of the all quinoline derivatives have excellent fast neutron shielding power compared to ordinary concrete. In addition, all quinoline derivatives have been found to have the capacity to attenuate gamma radiation. Moreover, they absorb well in both types of radiation, do not cause secondary radiation, and they are genotoxically safe at the tested concentrations. This study has demonstrated that these products can be used as active ingredients for a drug to be developed against radiation.

In this study, 3,4‐dihydro‐12‐aryl‐1H‐benzo[b]xanthene‐1,6,11‐(2H,12H)trione compounds were obtained through one‐pot condensation of various substituted aromatic aldehydes, 2‐hydroxy‐1,4‐naphthoquinone, and dimedone in the presence of Bi(OTf)₃ as a green and reusable catalyst. The structural characterization of these novel substituted benzo[b]xanthenes was performed by spectroscopic methods, and their inhibitory actions against butyrylcholinesterase (BChE), acetylcholinesterase (AChE), and glutathione S‐transferase (GST) were investigated. GST is an enzyme responsible for removing toxic molecules during Phase II reactions in the detoxification mechanism. The AChE and BChE enzymes, which are called cholinesterases, are among the enzymes that occur especially during dementia such as brain damage or Alzheimer's disease. Inhibition effects of the benzo[b]xanthene derivatives on AChE, BChE, and GST were found at the millimolar level. The best inhibitor for GST is compound 4a (31.18 ± 6.13 mM), for AChE, it is compound 4d (28.16 ± 3.46 mM), and for BChE, it is compound 4f (36.24 ± 3.19 mM). Compound 4a inhibited the dimerization of GST subunits, and compounds 4d and 4f directly inhibited the catalytic activity by interacting with the catalytic active site or a related site of the AChE and BChE enzymes, respectively.

In this study, substituted 1H-pyrazolo[1,2-b]phthalazine-5,10-diones which are considered that may possess biological activity have been obtained via one-pot multi-component cyclocondensation reaction of phthalhydrazide, aromatic aldehydes and malononitrile catalyzed in the presence of Cu(OTf)2 in very good yields and short times. The structures of all these synthesized compounds (4a-f) have been determined and characterized by infrared, nuclear magnetic resonance, mass spectral data, and elemental analysis.

In this study, substituted 2 H-indazolo[2,1- b]phthalazine-1,6,11-triones, that may possess biological activity, have been synthesized via one-pot three-component cyclocondensation reaction of...

In this study, the factors influencing the rate of chemical oxygen demand (COD) of a synthetic waste solutions containing water soluble reactive dye [Reactive Yellow 17 (RY17)] by ozone gas was investigated. The research was conducted using a semi-batch bubble column to take the advantage of the intensive back-mixing that prevails in bubble columns. As a result, the COD of disperse dyestuff wastewater was reduced to 78.58%, and decolorization was remarkable under the basic condition of pH 12, complete each dye degradation occurs in 12 min, ozone consumption goes on for a further 30 min after which time most degradation reaction is completed. Kinetic studies were exhibited that direct ozonation of the aqueous dyes were a pseudo-first-order reaction with respect to the dyes. The apparent rate constant increased with both applied ozone dose and higher pH values, declined logarithmically with the initial dye concentration.