Journal of the Iranian Chemical Society最新文献

An analytical method is presented for determining the uranium concentration in water samples via energy-dispersive X-ray fluorescence (EDXRF) spectrometry after solid-phase extraction. For the preconcentration procedure, the 1-(-2-thiazolylazo)-2-naphthol (TAN) reagent was used to complex the analyte in the samples. After the percolation of the sample and retention of the complex on a C18 disk, analysis was performed directly on the solid phase via EDXRF. The pH, sample flow rate, and sample volume were analyzed in terms of the uranium extraction. Using a sample volume of 110.0 mL buffered at pH 6.5 and a flow rate of 1.0 mL min⁻¹, an enrichment factor (EF) of 645 was achieved, with a limit of detection of 1.5 μg L⁻¹. The relative standard deviation (RSD, %), calculated from replications of the experiment under recommended conditions (n = 10; 20 μg L⁻¹), was 10%. The results of the analyte addition and recovery tests varied between 98 and 117%. The accuracy of the method was verified via analysis of a water reference material, with no significant difference between the obtained values and the certified values (95% confidence level). The method was applied to groundwater, river water, and tap water samples collected in Caetité, Bahia, Brazil, and the results were compared with those obtained via inductively coupled plasma‒mass spectrometry (ICP‒MS). All the collected samples presented uranium concentrations below the acceptable maximum limit for drinking water samples.

A range of fused heterocyclic compounds are generated utilizing the crucial intermediary 2-cyano-N-(2,5-dioxopyrrolidin-1-yl) acetamide 4. Spectral analysis was executed to support the structures of the newly synthesized compounds, which is expected to have a potential biological activity. The antimicrobial activity of the recently synthesized compounds and their derivatives has been tested against B. subtilis, S. aureus, E. coli, P. aeruginosa, S. typhimurium, C. albicans, and A. niger, as reference antibiotics, ampicillin and mycostatin, were used against test bacteria and fungi, respectively. In general, the novel produced compounds demonstrated a good antibacterial action against the previously indicated pathogens.

A series of twelve conjugates 9a-c, 10a-c, 11a-c, and 12a-c based on naturally occurring neo- and isocryptolepines I and II were synthesized and characterized. The synthetic pathways involved nucleophilic substitution reaction of the preprepared amines 4a-c and 5a-c with 1-(4-bromobutyl)indole derivatives 8a and 8b, respectively, in aprotic solvent under heating. The structures of the synthesized conjugates were elucidated by FTIR, ¹H NMR, ¹³C NMR, and MS spectrometry and showed data consistence with the expected structures. The antiproliferative activity of 9a-c, 10a-c, 11a-c and 12a-c was evaluated against HepG-2 and HCT-116 cancer cell lines using normal cells and reference drug paclitaxel. The screening results revealed that 9b and 9c were the most active conjugates against HepG-2 and HCT-116 cancer cell lines with IC₅₀: 8.49, 9.52, 16.87, 21.75 µM, respectively, using paclitaxel as a reference drug. It is worth noting that 9b and 9c were more selective toward cancer cells versus normal Vero cells. To rationalize the anticancer activity and selectivity of 9b and 9c, we have performed molecular docking study against human topoisomerases I and II for better understanding of their anticancer activities in atomic level. Molecular docking studies revealed that the presence of planar indoloquinoline fused four rings and a flexible side chain pharmacophores together improve DNA-intercalation and inhibition of DNA-Topo isomerases activity.

To investigate the retention mechanism of N-nitrosodiethanolamine (NDELA) in liquid chromatography, the mobile phase composition was changed on five stationary phases including silica, diol, cyano, amino, and zwitterionic. Afterward, temperature, pH, and buffer concentration effects are studied. Results demonstrate a dual hydrophilic interaction liquid chromatography (HILIC)-reversed phase (RP) mechanism for the retention of NDELA. The transition between the HILIC and RP behavior on a different column, “U-turn” points, was observed between 43 and 68% of water in acetonitrile. The depiction of the natural logarithm of retention factor vs. inverse of the absolute temperature was linear for cyano, amino, and zwitterionic columns. In contrast, it was curvature for silica and diol columns. In each column, the positive slopes indicate a negative retention enthalpy, signifying an exothermic process of transferring analytes from the mobile phase to the stationary phases being examined. In the case of buffer pH and concentration, an ammonium acetate solution with a pH of 5.7 and a concentration of 10 mM was selected for further investigation. Finally, the selectivity of this method in optimal conditions for the analysis of NDELA in shampoo has been investigated. According to the well-obtained selectivity of NDELA in shampoo and the advantages of the HILIC method, this method seems to be a suitable alternative to RP methods.

A series of 2-[(2,6-diarylpiperidin-4-yl)hydrazono]-2,3-dihydrothiazoles (25–40) were synthesized by the reaction of respective thiosemicarbazones (9–24) with phenacyl bromide in the presence of sodium acetate-acetic acid buffer and refluxing in ethanol for 12–16 h. The newly synthesized target compounds were characterized by elemental analysis, mass, FT-IR, ¹H and ¹³C NMR spectroscopic methods. A Structure activity relationship study was carried out for the title compounds against a panel of bacterial strains viz Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Bacillus subtilis and Klebsiella pneumonia and the fungal strains Cryptococcus neoformans, Candida albicans, Rhizopus sp, Aspergillus niger and Aspergillus flavus, respectively, using ciprofloxacin and amphotericin-B as standard drugs. These studies proved that compounds 26 and 34 against Staphylococcus aureus, 35 against P. aeruginosa, 38 against B. subtilis, and 27 against K. pneumonia showed maximum inhibitory potency at the lowest concentration (6.25 µg/mL), whereas 26, 34 and 35 against C. neoformans and 26 and 27 against Candida albicans showed beneficial antifungal activity at a minimum concentration (MIC) of 6.25 µg/mL.

A series of 1-(2-amino-2,4,5,6,7,7a-hexahydrobenzo[b]-3-yl)-3-substitued-phenylpropane-1,3-dionederivatives were synthesized using the Gewald synthesis in first step which is followed by Baker−Venkataraman rearrangement to yield title compounds. The FTIR, MS and 1H NMR results of the produced derivatives were validated. The biological potential such as antimicrobial, antioxidant and antimycobacterial activity against a particularly virulent strain of MTB (MTB H37Ra) of the synthesized compounds were examined. Antimicrobial screening outcomes showed that compound S₁₇ turned to be the most effective antibacterial agent against Gram positive bacteria such as Staphylococcus aureus (MIC = 16.87 µM) and Bacillus subtilis (MIC = 9.45 µM) and Gram negative bacteria such as Escherichia coli (MIC = 16.87 µM) and compound S₇ against Salmonella typhi (MIC = 9.74 µM) and compound S₁₆ displayed remarkable antifungal activity toward each Candida albicans and Aspergillus niger (MIC = 15.23 µM). The standard drugs, cefadroxil (antibacterial), have MIC value against S. aureus, B. subtilis, E. coli and S. Typhi are 16.40 µM, 32.80 µM, 16.40 µM and 16.40 µM, respectively, and fluconazole (antifungal) has MIC value 20.40 µM against both the C. albicans and A.niger strain. In comparison with ascorbic acid, a standard drug (IC₅₀ 44.91 µg/mL), compound S₁₀ demonstrated good antioxidant activity, with an IC₅₀ value of 45.29 µg/mL, according to the results of the antioxidant screening. The results of the in vitro antituberculosis screening showed that compound S₂₃ was found to be effective with an MIC value of 78.125 µg/mL. Molecular docking study of an enzymatic active site of “DprE1-decaprenylphosphoryl-β-D-ribose-2′-epimerase” shows a comparable binding mode to the native ligand with better docking score which contributes in understanding and development of models for ligand–protein interactions. Compound S₂₃ showed better docking score of − 8.516 as compared to the Isoniazid with the docking score of − 6.315 which in future will create the fundamental structural framework for MTB inhibition.

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The water splitting activity of (111) TiO₂ monolayer nanosheet and its mono and co-doped forms has been investigated by the periodic density functional theory (DFT) calculations. Upon Zr⁴⁺ mono-doping and even increasing the concentration of Zr⁴⁺ dopant, the band gap of the (111) TiO₂ monolayer becomes wider than that of the corresponding pure monolayer (3.9 eV), which reduces the photocatalytic efficiency. Fortunately, (S²⁻, Se²⁻, and Te²⁻) mono-doping and their increased concentration can effectively decrease the band gap by introducing midgap states above the valence band edge for the relevant monolayers. Moreover, the (Zr⁴⁺-S²⁻), (Zr⁴⁺-Se²⁻), and (Zr⁴⁺-Te²⁻) co-doping leads to a narrowed band gap and enhances the visible-light photoactivity of the (111) TiO₂ monolayer. Among considered monolayers, the Te²⁻-doped and (Zr⁴⁺-Te²⁻) co-doped (111) TiO₂ monolayers are the most desirable photocatalysts for hydrogen generation in this work.

Three new binary acidic deep eutectic solvents (DESs) were derived from tetrabutylammonium bromide (TBAB) as a hydrogen bond acceptor (HBA) coupled with azelaic acid (AzA), benzilic acid (BeA) and boric acid (BoA) as hydrogen bond donors (HBD). In order to draw the complete phase diagram and find the molar ratios in which the DESs are formed, HBA and HBDs were mixed together in the full range of molar ratios and their thermal behavior (by differential scanning calorimetry method) and stability were investigated. The activity coefficient models including Wilson, NRTL and regular solution were applied to correlate the measured solid–liquid equilibrium data. FT–IR and NMR analysis were used to investigate the chemical structures, occurrence the hydrogen bond formation between the DESs constituents and purity of the prepared DESs. Physicochemical properties of these DESs including melting point, density, and speed of sound, conductivity and refractive index were measured at different temperatures. The performance of these new DESs were successfully evaluated for the dissolution of four metal oxides including PbO, CuO, Fe₂O₃ and ZnO and the obtained solubility values were compared with the reported literature data.

Synthesis and properties of tetrahydroxy substituted zinc phthalocyanine is reported. UV–Visible spectrum for the aggregation properties of the compound and fluorescence properties were examined by excitation, emission spectra. This complex was an inhibitor of butyrylcholinesterase (BChE), α-Gly, α-Amy, and acetylcholinesterase (AChE) enzymes for tetra- hydroxy phthalocyaninato zinc (II) 3 with IC50 values of 49.18 μM for α-Amy, 110.85 μM for BChE, 35.13 μM for α-glycosidase and 54.63 μM for AChE, respectively. On the otherside, within the scope of computational study, in vitro activity behavior and states of the related complex, which cannot be explained experimentally, were evaluated at atomic level. The pharmacodynamics properties of the complex (3) were elucidated by molecular docking against four target enzymes, AChE, BChE, α-Gly and α-Amy. After that, its potential drug candidate was investigated based on its pharmacokinetic properties with help of in silico-ADMET analysis. As a result of all the applications, a desired goal in medicinal chemistry was to develop new, reliable and safe cholinesterase and α-glycosidase inhibitors with high efficacy.

Three novel rod-like molecules containing a bisthienylethene as π-conjugate rigid core with a different type of terminal functional atom (H, Cl, Br) were constructed by using Suzuki coupling and Knoevenagel reactions. The effect of the terminal functional atom on self-assembly behaviors in both bulk state and solution states and solid structures was investigated by using differential scanning calorimetry, polarized optical microscopy, small-angle X-ray scattering diffraction, density functional theory calculations and field-emission scanning electron microscopy. The non-halogen substituted compound and chlorinated compound are non-mesogen, whereas the brominated compound can self-assemble into a monotropic single-layer smectic A phase. The non-halogen substituted compound cannot form organogel in the common organic solvents, the chlorinated compound can form yellow-green fluorescent oragnogels in ethyl acetate and acetone, with rod-like morphology and brominated compound can form yellow-green, yellow or orange fluorescent oragnogels in ethyl acetate, acetone, 1,4-dioxane and toluene with sheet-like morphology. In addition, the terminal halogen atom induced great changes in the orderliness of solid morphology. Therefore, tuning terminal halogen atom could well lead to the transition of self-assembly behaviors in bulk state and solution state, which provides a way to obtain different self-assembly materials.