European Journal of Chemistry
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Utilization of mistletoe for the synthesis of copper nanoparticles and its clinical applications
No full textNanoparticles are substances with dimensions smaller than 100 nm. Nowadays, nanoparticles can be synthesized by many methods. Copper nanoparticles (CuNPs) were made using the green synthesis approach, using aqueous extracts of the pine mistletoe plant (Viscum album ssp. austriacum) and CuSO₄ metal salt. The formation of CuNPs was determined both by observing the color change and by the UV-vis method. Especially peaks were observed around the leaf (567 nm), fruit (560 nm), and branch (565 nm). Specific functional groups involved in the formation of CuNPs and the reduction of Cu0 were determined by FT-IR spectroscopy. In addition, SEM and EDS analyses of the synthesized CuNPs show that they are nanosized and their average size is less than 100 nm. In particular, it was determined that the size of fruit-derived CuNPs was the smallest (between 23.21 and 54.63 nm), and all synthesized CuNPs were spherical in shape. In addition, the antioxidant capacities of these plant extracts and CuNPs synthesized from them were investigated. For this purpose, DPPH• and ABTS•+ radical scavenging activities of the samples were determined. The DPPH• radical IC50 value of CuNPs obtained from the aqueous extract of fruit was determined as 151.41 µg/mL, and the ABTS•+ radical IC50 value was 160.43 µg/mL. The antioxidant results were compared with the standard ascorbic acid results. Furthermore, copper nanoparticles obtained from fruit extract were found to have the highest antioxidant activity. Furthermore, the antimicrobial activities of all samples were examined. In particular, the antiquorum activity of CuNPs synthesized from plant parts of V. album was determined for the first time. As a result, it was determined that the copper nanoparticles obtained from these plant parts had superior antioxidant and antimicrobial properties
Fluorinated pyrazolinic thiosemicarbazones: selective synthesis and computational analysis
Full text linkThiosemicarbazones are a class of iminic organosulfur compounds synthesized by condensation reaction between a thiosemicarbazide and an aldehyde or ketone. Such compounds present a wide range of biological activities, either as sole organic compounds or in association with metallic species. The fluorinated pyrazoline cyclic thiosemicarbazones described herein were synthesized from 4,4,4-trifluoro-1-phenyl-1,3-butanedione and three thiosemicarbazides. The reactions resulted in thiosemicarbazones 1, 2, and 3, with 51, 70, and 71% yields, respectively. which were characterized by elemental analysis, FTIR, 1H and 19F{1H} NMR, mass spectrometry and single crystal X-ray diffraction. The spectral data confirm that the thiosemicarbazones are cyclic the both in solid state and solution, as no evidence of ring-chain tautomerism has been observed. Additionally, single-crystal X-ray diffraction studies revealed that the compounds mentioned above crystallized in centrosymmetric space groups, two of them in monoclinic P21/n and the last one in triclinic P . Theoretical free energies of formation were calculated using the DFT methodology, and the results indicate that the ring isomer is significantly more stable than the chain isomer; thus, no ring-chain isomerism is expected to form, in agreement with the experimental data
Computational insights into anti-Zika quinazoline compounds: Density functional theory analysis, spectral properties, and molecular dynamics simulations
Full text linkZika disease, caused by the Zika virus (ZIKV), a mosquito-borne flavivirus, is a leading factor in the emergence and reemergence of serious illnesses. The compounds N-[4-((3-bromo-4-fluorophenyl)amino]-7-methoxyquinazolin-6-yl)-2-butynamide (1), N-[4-((4'-6-difluoro-[1,1'-biphenyl]-3-yl)amino)quinazolin-6-yl]-2-butynamide (2), and N-[4-((3-fluorophenyl) amino)-7-methoxyquinazolin-6-yl]but-2-ynamide (3) have been reported to exhibit anti-ZIKV activity. In this study, we performed geometry optimizations and structural analysis of these compounds using the B3LYP/6-31G** method. On the basis of the optimized geometries, the electronic properties, infrared (IR) assignments, and thermodynamic parameters were evaluated. The results indicate that these molecules maintain robust conformations in their core rings, with notable variations in the conformations of their side chains and functional groups. It was also observed that the rotational temperatures increase as the rotational constants decrease. The evaluated small HOMO-LUMO energy gaps and molecular electrostatic potential maps suggest high chemical reactivity, indicating ease of intramolecular charge transfer within the molecules. Infrared assignments for normal mode vibrations in the range of 400 to 3800 cm-1 were carried out successfully and compared for all three compounds. In addition, to study the structure function, the docking of these molecules along with the control molecule afatinib was performed with the methyltransferase enzyme of the Zika virus. The top-ranked docked complexes were subjected to a molecular dynamics simulation run of 200 ns duration. These theoretical calculations help us to understand how these compounds can interact with enzymes that are involved in the metabolic pathways of the Zika virus
Study of solid residues obtained from the pyrolysis of commercial plastic waste bottles by FTIR and TG methods
Full text linkThe composition of solid residues-products of thermal pyrolysis of plastic waste (polyethylene terephthalate (PET), polypropylene (PP)) at 350-550 °C was studied by Fourier transform infrared spectroscopy (FT-IR) and differential thermal analysis (DTA) methods. On the basis of the transition band (T%) the absorption and Abs parameters were calculated. It was observed that the Abs parameters of the peaks observed in the initial samples appear to change depending on the pyrolysis temperature, with the appearance of new peaks at higher temperatures. It was observed that during the pyrolysis of PET polymer waste, a number of bands with wavenumber 1692, 1670, 1262, 755, 694, and 464 cm-1 occurred at above 450 °C. It would seem that the Abs parameters for the 2923, 1453, and 846 cm-1 peaks observed in the initial samples are equal to zero. It would appear that during the pyrolysis of the PET polymer waste at 550 °C, only three peaks with wavenumbers of 1686, 1062 and 707 cm-1 are observed. Similarly, during the pyrolysis of the PP polymer waste at the same temperature, only one new peak (1092 cm-1) is observed. The solid residues of the pyrolysis processes for the samples taken at 550 °C are calculated and are equal to 13.6 and 0.6%, respectively, for PET and PP. The data shows that solid residues from the pyrolysis of PP wastes have a structure similar to that of charcoal
Enzyme-catalyzed kinetic resolution of spirocyclic secondary amines obtained by ring-closing metathesis, as well as synthesis of cyclopentane[c]pyrrole and -pyridines by the Pauson-Khand reaction
Full text linkAs herein defined; a ring closing metathesis (RCM) reaction of N-anchored homoallylic dienes followed by enzymatic kinetic resolution and ring closing enyne metathesis (RCEM) with an intramolecular Pauson-Khand reaction of N-tethered homopropargylic enynes are described for the first time. RCM afforded azaspirodeca and -undecadiene with 78 and 82% chemical yields, as well as azaspironona and decadienecarboxylates with 65 and 70% chemical yields, respectively. Furthermore, RCEM protocol resulted in conjugated diene 50% chemical yield. Moreover, intramolecular Pauson-Khand reaction is also applied to enynes, which yielded cyclopenta[c]pyrrole-carboxylate as diastereomeric mixtures; besides cyclopenta[c]pyridin-one and cyclopenta[c]pyridin-carboxylate frameworks as single diastereomers. Above all, secondary amines (azaspirodeca and undecadiene) have been efficiently resolved through an enzyme-catalyzed reaction in a moderate ee up to 77 and 20% ee, with their corresponding esters up to 75 and 55% ee, in the presence of CAL-B (being the most effective biocatalyst) and recombinant from Aspergillus oryzae. Both CAL-B and CAL-A-CLEA afforded reverse enantiomeric separation of them for the first time
Green synthesis and structural characterisation of a novel tetraoxadisiladiborocane-bridged thiadiazole oligomer and its transformation into a hydrogen-bonded 1D polymer
Full text linkThis study reports on the synthesis and characterization of novel cyclodiboradisiloxane derivatives. A one-pot 2+2 cyclo-condensation reaction of diphenylsilanediol and phenylboronic acid produced an eight-membered 2,2,4,6,6,8-hexaphenyl-1,3,5,7,2,6,4,8-tetraoxadisiladiborocane (Ph6B2Si2O4) (3). The reaction of compound 3 with 3,5-di-(3-pyridyl)-1,2,4-thiadiazole (L) and phenylboronic acid produced an oligomer (4) and a hydrogen-bonded-induced 1D polymer (5), respectively. Products (4 and 5) have been characterized by melting point, FT-IR spectroscopy, nuclear magnetic resonance, and single-crystal X-ray diffraction. Single-crystal X-ray diffraction revealed triclinic crystal systems with centrosymmetric space group for compounds 4 and 5. On the other hand, the hydrogen-bonded induced 1D polymer [Ph6B2Si2O4]·2L·2[PhB(OH)2] is colourless blocky cocrystals which also crystallized in the triclinic crystal system with a centrosymmetric space group of P-1. These two novel products (4 and 5) exhibit various intermolecular and intramolecular π-π non-covalent interactions and hydrogen bonds in their crystal packing. Compound 4 shows intramolecular non-covalent C-H···π (3.427 Å), C-H···N (2.601 and 2.684 Å), C-H···O (2.360 and 2.684 Å), C-H···S (2.601 Å and 2.701 Å) interactions in its crystal packings. In addition, compound 4 also displays some intermolecular short distance non-covalent interactions in its crystal packing such as π centroid···π centroid (3.805 Å) and C-H17A···π centroid (3.112 Å). On the other hand, the crystal packing of compound 5 also shows intra-molecular non-covalent C-H···π 3.440 Å, C-H···N 2.563 Å, C-H···O 2.654 Å, C-H···S 2.876 Å and H···B 2.939 Å interactions. Furthermore, compound 5 also exhibits short noncovalent intermolecular interactions in its crystal packing such as π···π, (3.362 Å, C14-C3 and 3.243, C11-C37), CH···π (2.587 Å, CH37A···πC38 and 2.452 Å, H7A···O42). The individual molecules of compounds 4 and 5 interact intermolecularly via C-H···N, C-H···O, C-H···S and N-B. Therefore, this study demonstrates the potential for the production of novel materials via the combination of cyclodiboradisiloxane (a Lewis acid) and a nitrogen-, oxygen-, and sulphur-containing ligand (a Lewis bases)
Crystallographic and Hirshfeld surface analysis of 10-(4-chlorophenyldiazenyl)-3-(3-chlorophenyl)-1-methyl-3,5a,6,11b-tetrahydro-5H-benzopyrano[4',3'-4,5]pyrano[2,3-c]pyrazole
Full text linkThe title compound, 10-(4-chlorophenyldiazenyl)-3-(3-chlorophenyl)-1-methyl-3,5a,6,11b-tetrahydro-5H-benzopyrano [4',3'-4,5]pyrano[2,3-c]pyrazole, crystallizes in the triclinic crystal system having the space group P-1 with the following unit cell parameters: a = 7.599(2), b = 11.596(3), c = 12.796(3) Å, α = 90.092(5), β = 94.810(5), γ = 90.583(5)°, Z = 2. The crystal structure was solved by direct methods using single-crystal X-ray diffraction data collected at 100 K and refined by full-matrix least-squares procedures to a final R-value of 0.0636 for 2578 observed reflections. All three phenyl rings A, B, and F are planar. The pyrazole ring E is also planar. Rings C and D are in half-chair conformation with asymmetry parameters: ΔC2(C7a-C11a) = 3.02 and ΔC2(C3a-C11c) = 4.02, respectively. Hirshfeld surface is a 3D boundary around a molecule/crystal structure based on electron density. The Hirshfeld surface analysis revealed dominant H···H (31.0%), H···Cl (26%), and H···C (18%) interactions, contributing to crystal stability and packing efficiency. Molecular docking studies further indicated a strong and stable ligand-enzyme interaction, highlighting its potential for small-molecule inhibitor development
Zinc oxide-catalyzed UV-photodegradation of cyhalothrin: A kinetic analysis
Full text linkIn this study, we present kinetic studies of the photodegradation of cyhalothrin (CyH) under ultraviolet (UV) irradiation and the photocatalytic activity of zinc oxide (ZnO) in UV-assisted photodegradation. CyH in an acetone solvent was periodically exposed to UV254 nm radiation light with a surface power density of 48 W/cm2. The photodegradation experiments were conducted by acquiring periodic wavelength-scan spectroscopic data using a double beam ultraviolet-visible (UV-vis) spectrophotometer and plotting the real-time absorbance data to monitor the reaction coordinate. Under our optimized conditions at room temperature of 26.5 °C, atmospheric pressure of 76.6 mmHg, CyH (5.0 ppm) in the 70% acetone solvent with pH = 6.8 and dose of ZnO (25 ppm) exhibited typical photodegradation efficiencies between 81.9 and 90.3 % within the first 1,200 seconds of UV irradiation. Spectroscopic data showed that the ZnO solution significantly elevated the UV-assisted photodegradation rate of CyH by about 7.03 - 7.18 times more than that of UV-only-mediated CyH photodegradation. The result confirmed and characterized the photocatalytic activity of ZnO. Under the optimized measurement conditions, the rate of the ZnO-catalyzed photodegradation of CyH was found to follow the first-order rate law (RSq. = 0.999)
The role of water and iodine in supramolecular assembly of a 2D coordination of benzimidazole derivate: X-ray crystallography and DFT calculations
Full text linkTo understand the relationships between molecular structure and properties, as well as to validate predictive models, density functional theory (DFT) and experimental characterization of molecules are essential. In this study, we describe the synthesis and crystal structure of the 1,3-dimethyl-3H-benzimidazol-1-ium iodide monohydrate (DBZIW), which crystallizes in a monoclinic system with the space group P21/c, a = 8.9323(4) Å, b = 7.1654(3) Å, c = 17.6425(8) Å, β = 101.432(2)°, V = 1106.78(8) Å3, Z = 4, T = 293(2) K, μ(MoKα) = 2.860 mm-1, Dcalc = 1.753 g/cm3, 9452 reflections measured (4.652° ≤ 2Θ ≤ 55.512°), 2547 unique (Rint = 0.0244, Rsigma = 0.0222) which were used in all calculations. The asymmetric unit comprises a [C9H11N2]+ molecule, an iodine ion (I-), and a water molecule. The B3LYP/6-311++G(d,p) diffuse function was used to optimize the structures of 1,3-dimethyl-3H-benzimidazol-1-ium (DBZ) and 1,3-dimethyl-3H-benzimidazol-1-ium monohydrate (DBZW), while the structures of 1,3-dimethyl-3H-benzimidazol-1-ium iodine (DBZI) and 1,3-dimethyl-3H-benzimidazol-1-ium iodide monohydrate (DBZIW) were optimized using the B3LYP/Def2-TZVP method due to the presence of the iodine ion. These optimizations were performed using Gaussian09 software, and both models accurately predicted the bond lengths, bond angles, and torsion angles of the molecules. Furthermore, DFT calculations were employed to determine the HOMO-LUMO energy levels, energy gap, softness, hardness, and other quantum chemical parameters. A strong intermolecular hydrogen bond interaction, along with the aromatic ring system and the fusion of benzene and imidazole, constitutes a small but highly significant structure that has been confirmed. The O1 atom of the water molecule and the iodine ion (I-) participate in a significant hydrogen bond interaction (O-H···I) within the molecular packing of DBZIW. Furthermore, the network of C-H···O hydrogen bond contacts plays a crucial role in the stability of the structure. Hirshfeld surface analysis was carried out to identify the various hydrogen bonds. The energy frameworks for the compounds were constructed through based on intermolecular interaction energies to know ascertain dominant interaction energy involved contributing to the strength of the packing. Molecular studies indicated that DBZIW had exhibits high binding affinity for thyroid-stimulating hormone receptor (TSHR) protein targets (4QT5)