Turkish Journal of Chemistry最新文献

Paclitaxel (Pac) is an important anticancer bioactive compound, and the availability of an accurate and robust analytical method for its quantification is of utmost importance. In this investigation, a novel, direct, and reliable spectrophotometric method has been proposed for the estimation of Pac via a complex formation reaction with osmium (Os). The method was based on the reaction of Pac with Os tetroxide, which produced a yellowish-brown complex. The resulting complex is soluble in water and displays a maximum absorption peak at 482 nm. The reaction conditions, including reactant concentration, pH, temperature, and reaction time, were optimized to obtain the best spectrophotometric response. A thorough method validation study was conducted, demonstrating that the calibration curve is linear over the concentration range of 1.0-55 μg/mL and follows Beer's law, with a molar absorptivity of 3.01 × 10^-4 L/mol^-1.cm^-1. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.0098 and 0.0328 μg/mL, respectively. The recovery values were planned and found to be 98.70%-100.23%. At the same time, the precision values (represented by relative standard deviation percent [RSD%]) were better than 0.81% (in injections) and 1.859% (in biological fluids), depending on the Pac concentration. The suggested method was successfully applied to estimate Pac in a pharmaceutical formulation (as injections) and in spiked biological fluids (serum and urine), with results showing good accuracy and precision compared to the reference method.

Hypochlorous acid (HOCl) is a potent nonradical oxidant involved in various physiological processes, particularly within the human immune system. In this study, we introduce a novel, rapid, and highly efficient fluorometric method for the detection of HOCl. The method utilizes a near-infrared (NIR)-based fluorescent probe, NIR-QBH, which is characterized by its high sensitivity and chemical stability. NIR-QBH, containing olefinic C=C bonds, exhibits strong NIR emission at 660 nm (λ_ex = 618 nm). The detection mechanism relies on the oxidation of the C=C bond in the NIR-QBH structure by HOCl, resulting in the formation of non-fluorescent products. With a detection limit of 0.23 μM, the probe demonstrates a fast response time of 4 min. Glutathione (GSH), an essential biothiol, was employed as a reference HOCl scavenger, and its HOCl scavenging activity was evaluated with an IC₅₀ value of 8.97 μM. Furthermore, the developed fluorometric assay was successfully applied for the detection of HOCl in fetal bovine serum (FBS) and aqueous solutions.

In this study, Pt/WO₃ nanoparticles were synthesized using a simple room-temperature impregnation-reduction method and characterized by advanced techniques including ICP, TEM-EDX, FE-SEM-EDX, and XRD. The ICP-OES analysis confirmed a 1.0 wt. % Pt loading on the WO₃ support. TEM and FE-SEM analyses revealed that the Pt nanoparticles were well dispersed with an average size of approximately 3.7 nm. The XRD patterns showed characteristic WO₃ peaks without any detectable Pt diffraction peaks, indicating the high dispersion of Pt. Electrochemical evaluations demonstrated that the Pt/WO₃ catalyst exhibited outstanding hydrogen evolution reaction (HER) performance, with -27.8 mV vs. RHE onset potential and -37.4 mV overpotential at 10 mA.cm^-2, outperforming bare WO₃. The Tafel slope (b) of 68.6 mV·dec^-1 indicates efficient reaction kinetics following the Volmer-Heyrovsky pathway. The impedance analysis confirmed efficient charge transfer, with a b value of 69.7 mV.dec^-1. The ECSA was calculated as 8.575 cm², highlighting the high surface activity of the catalyst. Stability tests showed minor degradation but retained significant catalytic activity. This work emphasizes the potential of Pt/WO₃ as an environmentally friendly, cost-efficient catalyst with promising applications in HER, providing a scalable and effective approach to hydrogen production.

Climbazole (CBZ) is an antifungal active pharmaceutical ingredient often used in antidandruff products. In this study, the ketone group in the racemic CBZ molecule was reduced to synthesize CBZ-alcohol, named 1-(4-chlorophenoxy)-1-(1H-imidazol-1-yl)-3,3-dimethylbutan-2-ol, and the optimum adsorption conditions were investigated for removing iron(II) (Fe²⁺) ions from wastewater by adsorption from aqueous solutions using the economical and environmentally friendly ultrasonic method. The parameters and levels used in the study were designed using response surface methodology and model equations were derived to optimize the results. The independent variables selected were the initial pH (1, 3, and 5), adsorption time (30, 45, and 60 min), adsorption temperature (40, 60, and 80 °C), and Fe²⁺ ions consumption percentage from the wastewater. Experiments were conducted on a real wastewater sample taken from the Uşak Organized Industrial Zone. Conditions that maximize each dependent variable were specified separately and verification experiments were conducted under these conditions. Maximum Fe²⁺ ion consumption was 91.83%. The R² value of the model was 0.9598. The findings demonstrate that CBZ-alcohol was effective as an adsorbent in Fe²⁺ ion removal from aqueous solution.

Industrial wastewater from sectors such as textiles, printing, and pharmaceuticals contain harmful pollutants, including nonbiodegradable dyes, which pose significant challenges for environmental safety. Neutral red, a cationic dye commonly found in wastewater, obstructs photosynthesis in aquatic ecosystems and carries potential toxicity. Traditional methods of dye removal often prove ineffective due to the chemical stability of these compounds. In this study, oxygen-doped graphitic carbon nitride (O-doped g-C₃N₄) was synthesized as an innovative photocatalyst for the degradation of neutral red dye under visible light. The material was synthesized through a sustainable process involving the calcination of urea, dicyandiamide, and oxalic acid, and its characteristics were evaluated using various techniques, including XRD, FT-IR, UV-Vis spectroscopy, and SEM. Photocatalytic degradation of neutral red was analysed using a custom photoreactor under visible light. The results demonstrated that O-doped g-C₃N₄ exhibited enhanced photocatalytic efficiency compared to pure g-C₃N₄, reducing the recombination of electron-hole pairs and effectively degrading the dye. Adsorption kinetics followed a pseudo-2nd-order model, while adsorption isotherms suggested that the Langmuir model best described the adsorption process, indicating monolayer adsorption. The maximum adsorption capacity of O-doped g-C₃N₄ for neutral red was 9.643 mg g^-1, surpassing pure g-C₃N₄. The photocatalytic performance of OCN-UD was assessed under visible light, revealing a significant degradation efficiency of 86% for neutral red after 60 min, compared to 51% for pure g-C₃N₄. Kinetic studies indicated that the adsorption of neutral red onto OCN-UD primarily followed a pseudo-2nd-order model, demonstrating chemical adsorption processes. The synergistic effects of adsorption and photocatalysis were evident, as the initial adsorption phase concentrated dye molecules near active sites, facilitating efficient photocatalytic degradation through reactive oxygen species generation. This study highlights the potential of O-doped g-C₃N₄ as an efficient, eco-friendly solution for the treatment of dye-laden wastewater.

Since PI3Ks are targeted by a variety of bacterial pathogens, they represent a promising target for host-directed immune therapy and may be beneficial in managing persistent bacterial infections. In the present study, computational studies of 5-(pyridin-4-yl)-1,3,4-thiadiazol-2-amine derivatives for phosphoinositide-3-kinases (PI3Ks) inhibitors were carried out using dock scores, Glide scores, and the MMGBSA dG method, with comparison to standard drugs (ofloxacin and fluconazole). A series of 5-(pyridin-4-yl)-1,3,4-thiadiazol-2-amine derivatives (D1-D17) were synthesized and evaluated for their in vitro antimicrobial activity against both gram-positive and gram-negative bacterial strains, as well as fungal strains, using the tube dilution method. The synthesized compounds were characterized based on their physicochemical properties, and spectral data confirmed consistency with the proposed molecular structures. Docking studies, the MMGBSA analyses, and in vitro antimicrobial activity results indicated that compounds D₄, D₆, D₈, and D₁₂ were the most active against different microbial species and also showed favorable docking results in comparison with the PDB ligand and standard antimicrobial drugs (ofloxacin and fluconazole). This study highlights the potential of these compounds for future in vivo antimicrobial and anticancer investigations.

This study presents a ternary WO₃/α-Fe₂O₃/Bi₂S₃ photoanode system suitable for photoelectrochemical water-splitting applications. WO₃/α-Fe₂O₃ heterojunction is obtained using a hydrothermal approach, while Bi₂S₃ is deposited onto WO₃/α-Fe₂O₃ via the successive ionic layer adsorption and reaction (SILAR) method. The cycle count is adjusted to determine the optimal photocatalytic photoanode. X-ray diffraction analysis confirms different morphologies and phases for the photoelectrodes: WO₃ is deposited as plates with monoclinic phases, α-Fe₂O₃ as nanorods with hexagonal phases, and Bi₂S₃ in the form of nanoparticles (NPs) with orthorhombic phases. Solar light absorption spectra indicate that ternary WO₃/α-Fe₂O₃/Bi₂S₃ photoanodes absorb a larger portion of the solar spectrum and display a large red shift in wavelength compared to binary WO₃/α-Fe₂O₃ photoanodes. Chronoamperometric and electrochemical impedance spectroscopy measurements indicate that the as-prepared WO₃/α-Fe₂O₃/Bi₂S₃ photoanode exhibits notable stability and low charge transfer resistance (R_ct) compared to binary electrodes and pristine WO₃ plates in faradaic photoelectrochemical conversion for the oxygen evolution reaction and S^-2/S² processes. Linear sweep voltammetry studies show that the WO₃/α-Fe₂O₃/Bi₂S₃ photoanode, sensitized with 8 SILAR cycles, achieves the maximum photocurrent density of 5.777 mA.cm^-2 at 1.0 V vs. RHE under 100 mW cm^-2 simulated solar irradiation.

The article presents the results of the interaction conditions of CuCl₂ and As₂S₅ in ethylene glycol and aquatic medium. Besides, the results of the obtained samples' physicochemical properties are given by X-ray diffraction (XRD), differential thermogravimetric (DTG), thermogravimetric (TG), elemental, and scanning electron microscope (SEM) methods. It was found that when ethylene glycol and water are used as a solvent and CuCl₂ and As₂S₅ as the initial components, Cu₃AsS₄ is obtained at a temperature of 323-353 K. According to the results of DTA analysis, it was found that the melting point of obtained samples was 964.4 K contrary to the reactions carried out to obtain Cu₃(AsS₄)₂ compounds both in ethylene glycol and water medium. Elemental analysis of the compounds was carried out, energy-dispersion spectrum, mass, and atomic ratios of copper, arsenic, and sulfur were determined, and the stoichiometric composition of Cu₃AsS₄ was determined. Furthermore, X-ray analysis of the obtained samples confirmed that peaks on the graphs correspond to the standard intensity maxima of the Cu₃AsS₄ compound.

The synthesis of novel heterocyclic compounds, particularly those targeting critical signaling pathways in cancer, represents a promising approach to drug development. In this study, we designed and synthesized a series of thiazole-integrated pyrrolotriazinone derivatives, aiming to combine the antiproliferative properties of thiazole with the PI3K inhibitory activity of pyrrolotriazinones. The PI3K pathway, which plays a critical role in regulating cell growth, proliferation, and survival, is frequently dysregulated in cancer, making it an attractive target for therapeutic intervention. The synthesized derivatives were evaluated for their cytotoxic activities against MCF-7, A549, and HepG2 cancer cell lines. Their effect on PI3K protein levels was assessed to evaluate their potential as PI3K inhibitors. Preliminary results indicate that these thiazole-pyrrolotriazinone hybrids exhibit significant cytotoxic effects and may reduce PI3K protein levels in cancer cells. Furthermore, drug-likeness assessments and pre-ADMET evaluations demonstrated that the compounds exhibited promising characteristics, supporting their potential as viable drug candidates. Overall, this study highlights the potential of these novel compounds in cancer therapy and provides valuable insights into the design of small molecules that can target key regulatory pathways involved in cancer progression.

In the past few years, perovskite solar cells (PSCs) have gained a lot of attention and become a well-known topic in solar studies due to their lower manufacturing costs and improved efficiencies. Previously utilized hole transport materials (HTMs), such as poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] and 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene, are challenging due to their high price, complicated synthesis, limited carrier mobility, and poor device stability. Developing HTMs for PSCs that are inexpensive and high-performance has gained much interest. Currently, many HTMs of organic molecules are used to improve photovoltaic qualities and reduce synthesis costs. Effectively using HTMs is essential for producing the best photovoltaic efficiency in PSCs because they are essential in extracting and transporting charge carriers. Pyrene-based HTMs have excellent device performance, chemical stability, and photovoltaic qualities compared to the other organic moieties. The significant developments made in pyrene-based HTMs over the past five years are reported herein. This review analyzed the relationship between the molecular structure, hole mobility, highest occupied molecular orbital-lowest unoccupied molecular orbital energy levels, power conversion efficiency (PCE), and energy band gap of pyrene-based HTMs. It was revealed that PSC devices fabricated with pyrene-based HTMs have attained a PCE greater than 22%. It is hoped that this review will encourage more researchers to develop HTMs that have good performance, low cost, and high device stability.