Journal of the Iranian Chemical Society最新文献

In the present study, a modified carbon nano-onion and β–cyclodextrin composite was utilized in micro-solid phase extraction of atenolol and metoprolol from human plasma samples. The synthesized sorbent structure and morphology were evaluated. In this method, a proper amount of the sorbent was contacted with the diluted plasma sample under vortexing (to promote the sorbent contact area with the solution). The separated particles by centrifugation were contacted with a proper eluent to desorb the target analytes. After that, the eluent was separated by centrifugation and used during analysis of the analytes by high-performance liquid chromatograph. Several effective extraction parameters such as the sorbent amount, type and elution solvent volume, and extraction time were evaluated and optimized. The validated factors showed that detection and quantification were 0.09 and 0.01 and 0.29 and 0.03 ng mL^–1, for metoprolol and atenolol, respectively. The method precision, considered as relative standard deviation, was ≤ 2.5 and ≤ 3.6% for intra- (n = 5) and inter-day (n = 4) precisions, respectively. The extraction recovery values were obtained 84 and 63% for metoprolol and atenolol, respectively. Lastly, the developed method was utilized successfully on the plasma samples of patients treated with metoprolol and atenolol.

In order to improve the activity of copper (Cu) towards electrolytic reduction of nitrate, thin films of magnesium hydroxide (Mg(OH)₂) were deposited on Cu substrate. For the first time, these films were synthesized by electrochemical deposition in a potassium sulfate bath containing Mg²⁺ at 70 °C. The effect of various experimental parameters, such as deposition time and potential, on the electrocatalytic activity for the nitrate reduction was investigated. Surface analysis techniques (SEM, EDX and XRD) were used to get information on the morphology, the composition and the structure of the deposits. The activity of the modified electrode was studied by cyclic voltammetry, and amperometric method. The modified Mg(OH)₂/Cu sensor exhibited a good electrocatalytic behavior towards the reduction of nitrates with high reproducible reduction peak currents. In addition, the sensor exhibits a linear answer for concentration in nitrate between 0.125 to 7 mM, combined with high sensitivity (24.6 µA mM⁻¹ cm⁻²) and limit of detection (225.35 µM) values. When common interfering molecules were added to the solution, Mg(OH)₂/Cu electrodes have kept their good selectivity. They demonstrated acceptable detection levels for nitrates in tap water.

Luteolin (Lut) is a flavonoid compound with antioxidant, anti-inflammatory and other biological properties. Lut has been used in many fields such as biomedicine and food safety. Therefore, the quantitative measurement of Lut is of great significance. In this study, an electrochemical sensor based on aminated multi-walled carbon (NH₂-MWCNTs), sodium carboxymethylcellulose (CMC), ZIF-67 and chitosan (Chi) is developed for the measurement of Lut. NH₂-MWCNTs are better dispersed by CMC, and NH₂-MWCNTs are cross-linked with ZIF-67, which further improves the response and sensitivity of the electrode to the Lut due to the peroxide-like properties of ZIF-67. The detection limit and linear range of the electrochemical sensor for Lut are 2.1 nM and 0.1–7 μM, respectively. Dandelion is a traditional Chinese medicine plant containing Lut component. The prepared electrochemical sensor is also used to analysis Lut content in various parts of dandelion. The results show that the flowers part of dandelion exhibits the highest concentration of Lut; while, the leaves contain a moderate amount, and the roots are nearly devoid of Lut. These results are consistent with those obtained by ultra-high performance liquid chromatography. The electrochemical sensor has good stability and anti-interference ability, and has good potential application value in drug concentration detection and screening.

Graphical Abstract

To enhance the photogeneration and separation of charge carriers, ZnO/MnO₂ nanocomposites were efficiently synthesized using a simple hydrothermal process and tested as photocatalyst for dye degradation. The samples of ZnO, MnO₂, and ZnO/MnO₂ nanocomposites were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reflection spectroscopy, and photoluminescence spectra (PL). The photocatalytic activity of the ZnO/MnO₂ prepared using 10 mg was significantly higher than that of ZnO or MnO₂, as demonstrated by optical and photoluminescence measurements. In fact, the degradation efficiency of methyl orange (MO) with ZnO/MnO₂ (10 mg) reaching to 98% after 2 h of sunlight irradiation. The enhanced degradation of MO compared with pure ZnO and MnO₂ can be attributed to the high surface area, efficient sunlight absorption, and excellent charge carrier separation of the ZnO/MnO₂ photocatalyst. Density functional theory (DFT) simulations of ZnO and MnO₂ further revealed the electronic origins of the structural properties, showing that the photocatalytic activity is due to the electron transitions between the valence and conduction bands of materials.

Sulfamerazine (4-Amino-N-(4-methylpyrimidin-2-yl) benzenesulfonamide) is a polymorphic molecule crystallizing in three forms: Form I: Pn2₁a polymorph (with three entries in the Cambridge Structural Database CSD), Form II: Pbca polymorph (with two entries in the CSD) and Form III: P2₁/c polymorph with only one entry in the CSD). We have experimentally prepared a novel monoclinic P2₁/c polymorph (Form IV) of the sulfadrug and also obtained crystals of Form II (Pbca polymorph) by following a different synthesis procedure. Both crystals were structurally characterized by single-crystal X-ray diffraction XRD and geometrically optimized by density functional theory DFT. The five crystal structures (1), (3)–(6) of the four mentioned polymorphs were analyzed and discussed in terms of crystal packing, Hirshfeld surface analysis HSA of the intermolecular interactions, voids’ distribution in the crystal packing, their related energies and the resulting underlying topologies. The energy and activity relations of the compounds were also investigated by DFT.

A series of 21 novel compounds based on noscapine were synthesized and investigated as potential anticancer therapeutics. These new compounds were prepared from the N-demethylation of noscapine followed by the three-component A³-coupling of N-nornoscapine as a secondary amine, an aldehyde and a terminal alkyne catalyzed by copper iodide (CuI). Two classes of derivatives were synthesized by applying phenylacetylene and propargyl alcohol as the alkyne moiety. Chemical structures of the products were confirmed by ¹HNMR, ¹³CNMR, and HR-MS. In vitro cytotoxicity of the synthesized derivatives was studied on MCF-7 breast cancer cell line treated with different doses of compounds for 48 h. Compounds 6l, 6n and 6h (IC₅₀ = 18.94, 19.29 and 32.11 µM, respectively) displayed the highest potency compared to that of noscapine (IC₅₀ = 36.38 µM).

Nanoparticles particularly titanium dioxide (TiO₂) have demonstrated remarkable potential in both photocatalytic degradation of the toxic compounds and development of the effective photodynamic therapy (PDT) by harnessing light-induced reactive oxygen species (ROS) generation. In PDT, the choice of appropriate photosensitizers (PSs) and optimal light sources is crucial for the therapeutic efficacy. Pure titanium dioxide has the drawbacks of limited tissue penetration and high cytotoxicity due to the triggered traditional ultraviolet light sources, rapid recombination rate of the electron (e⁻)/hole (h⁺) pairs attributed to their broader band gap energy, and low solubility with high tendency to aggregation in water. Reproducible synthesis and efficiency optimization in ROS generation are also among the challenges. Addressing these challenges, this study focuses on the construction of a novel PDT nanoplatform: design and synthesis of the biocompatible N-doped-TiO₂/FeTCPP (PFNT) by modifying TiO₂ nanoparticles with urea as a safe nitrogen source (NT) to create an efficient type I PS, which expands the optical absorption capacity between 400 and 800 nm due to the facilitated localized nitrogen states within the titanium dioxide band gap, as well as by incorporating iron metalloporphyrin FeTCPP (tetra(4-carboxyphenyl) porphyrin) as an effective type II PS. Upon visible-light irradiation, FeTCPP not only sensitizes singlet oxygen, but also transfers electrons from excited FeTCPP* species to Ti⁴⁺-based N-TiO₂ to afford FeTCPP^•+ ligands and Ti³⁺ centers, thus propagating the production of hydrogen peroxide, superoxide, and hydroxyl radicals. By generating the substantial distinct ROS, significant tumor cell killing was obtained under LED irradiation, particularly in addressing melanoma. This research underscores substantial promise of the designed N‐TiO₂/FeTCPP nanocomposites in advancing the field of PDT-based cancer therapy, paving the way for efficient and targeted treatments.

Complexes of first row transition metals are a promising class of inexpensive catalysts for oxidation reactions. In this work, we studied the influence of covalent immobilization of Mn-porphyrin onto the surface of activated carbon in the green oxidation of various olefins. meso-tetrakis(4-carboxyphenyl)porphyrinatomanganese(III) acetate (MnTCPP) immobilized onto hydroxylated activated carbon (AC-OH). The anchored catalyst was characterized using FTIR, UV–VIS, atomic absorption and EDX spectroscopies. TGA analysis and BET-BJH method were employed to determine thermal behavior and surface properties of complex respectively. Then, catalytic performance of MnTCPP@AC-OH was investigated in the green oxidation of olefins with molecular oxygen and hydrogen peroxide. A comparison between two green oxidants (molecular oxygen and hydrogen peroxide) shows that although more product is obtained with hydrogen peroxide, more recyclability is obtained with molecular oxygen. The separation and recovery of the nanocatalyst was simple, effective and economical in this green oxidation method and the supported catalyst can be reused at least five times without significant loss of activity.

In the current study, we synthesized copper oxide nanostructures (CuO NSs) via a facile hydrothermal procedure. We characterized them with the help of scanning electron microscopy (SEM) and X-ray diffractometry (XRD). SEM study revealed that CuO NSs inherited nanoneedles-based flowering geometry with a porous nature, while XRD proved the crystalline nature of these NSs. When deposited on a glassy carbon electrode (GCE), these nanostructures are displayed as a sensitive sulfite detection tool in the sample matrix. The results showed that sodium hydroxide, with pH 10.0, was the best-supporting electrolyte among all electrolytes studied. The as-prepared sulfite sensor performed well in a linear working range of 10–100 µM sulfite with the low detection limit (LOD) of the amperometry technique used to evaluate the analytical performance of the electrode, such as a limit of 1.12 µM. The developed sensor was highly stable and reproducible, showing a relative standard deviation of 2.17% for 10 cycles. The sensor also exhibited more selectivity for sulfite in the presence of probable interfering species, including cyanide, sulfate, chloride, and nitrate. The findings further proved the CuO/GCE-Nafion-based sensor as a sensitive diagnostic tool for quantifying or monitoring health-hazardous sulfite in the environmental sample matrices.

We have designed a series of 17 new 2-(trifluoromethyl)-1H-benzimidazoles based on alkylation with ethyl chloroacetate. The corresponding ester underwent saponification and hydrazinolysis to afford the corresponding acid and hydrazide, respectively. Hydrazide reacted with aromatic aldehydes and isothiocyanates and gave the corresponding hydrazones and thiosemicarbazide, respectively. The hydrazide and acid derivatives were used to attach an amine; primary and secondary amines via “DCC and azide coupling” methods to finally give a series of N-alkyl-2-(2-(trifluoromethyl)-1H-benzimidazol-1-yl)acetamides with a wide range of lipophilic and hydrophilic features. The most active compound was tested for cytotoxicity against MCF-7 cells using the MTT assay. Some compounds demonstrated activity against two proteins, interacting with key amino acids like the co-crystallized ligands such as compound 7d. Compound 7d exhibited potent cytotoxicity with an IC₅₀ value of 0.51 μM compared to Doxorubicin (IC₅₀ = 2.12 μM).