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RSC Advances May 2024This study presents a description of the catalytic synthesis of indeno[1,2-]indolone derivatives. In this method, initially, a Schiff base compound was synthesized from...
Fabrication and characterization of inorganic-organic hybrid copper ferrite anchored on chitosan Schiff base as a reusable green catalyst for the synthesis of indeno[1,2-]indolone derivatives.
This study presents a description of the catalytic synthesis of indeno[1,2-]indolone derivatives. In this method, initially, a Schiff base compound was synthesized from the reaction of acetylacetone with 2-hydroxyaniline. Then, the prepared Schiff base was immobilized on chelated magnetic copper ferrite nanoparticles with a chitosan surface to design and prepare the CuFeO@CS-SB nanocomposite. Further, the one-pot multi-component cyclization reaction of aniline, dimedone and ninhydrin was conducted using the synthesized nanocomposite as a heterogeneous acid catalyst in water solvent under thermal conditions. In this reaction, the products were obtained in excellent yields and short reaction times, and the catalyst could be recycled and reused six times without any loss in product yields. By conducting FT-IR spectroscopy, H NMR spectroscopy, XRD, FE-SEM, TGA, elemental mapping scanning, EDX and BET analyses, the structure of the nanocatalyst was characterized. In addition, for the identification of organic compounds, FT-IR, H NMR, and C NMR spectroscopies and melting point analysis were used, which confirmed the synthesis of this class of derivatives.
PubMed: 38812959
DOI: 10.1039/d3ra08705k -
RSC Advances May 2024Chromones are well known as fundamental structural elements found in numerous natural compounds and medicinal substances. The Schiff bases of chromones have a much wider... (Review)
Review
Chromones are well known as fundamental structural elements found in numerous natural compounds and medicinal substances. The Schiff bases of chromones have a much wider range of pharmacological applications such as antitumor, antioxidant, anti-HIV, antifungal, anti-inflammatory, and antimicrobial properties. A lot of research has been carried out on chromone-based copper(ii) Schiff-base complexes owing to their role in the organometallic domain and promise as potential bioactive cores. This review article is centered on copper(ii) Schiff-base complexes derived from chromones, highlighting their diverse range of pharmacological applications documented in the past decade, as well as the future research opportunities they offer.
PubMed: 38808245
DOI: 10.1039/d4ra00590b -
Pharmaceuticals (Basel, Switzerland) May 2024In this innovative research, we aim to reveal pyrazole-based Schiff bases as new multi-target agents. In this context, we re-synthesized three sets of pyrazole-based...
Exploring the Potential Biological Activities of Pyrazole-Based Schiff Bases as Anti-Diabetic, Anti-Alzheimer's, Anti-Inflammatory, and Cytotoxic Agents: Studies with Computational Predictions.
In this innovative research, we aim to reveal pyrazole-based Schiff bases as new multi-target agents. In this context, we re-synthesized three sets of pyrazole-based Schiff bases, -, -, and -, to evaluate their biological applications. The data from biological assays (including antioxidant and scavenging activities, anti-diabetes, anti-Alzheimer's, and anti-inflammatory properties) of the pyrazole-based Schiff bases -, -, and - showed that the six pyrazole-based Schiff bases , , , , , and possess the highest biological properties among the compounds evaluated. The cytotoxicity against lung (A549) and colon (Caco-2) human cancer types, as well as normal lung (WI-38) cell lines, was evaluated. The data from the cytotoxicity investigation demonstrated that the three Schiff bases , , and are active against lung (A549) cells, while the two Schiff bases and exhibited the highest cytotoxicity towards colon (Caco-2) cells. Additionally, the enzymatic activities against caspase-3 and Bcl-2 of the six pyrazole-based Schiff bases , , , , , and were evaluated. Furthermore, we assessed the absorption, distribution, metabolism, and toxicity (ADMT) properties of the more potent pyrazole-based Schiff bases. After modifying the structures of the six pyrazole-based Schiff bases, we plan to further extend the studies in the future.
PubMed: 38794225
DOI: 10.3390/ph17050655 -
International Journal of Molecular... May 2024The interactions with calf thymus DNA (CT-DNA) of three Schiff bases formed by the condensation of hesperetin with benzohydrazide (HHSB or LH), isoniazid (HIN or LH), or...
The interactions with calf thymus DNA (CT-DNA) of three Schiff bases formed by the condensation of hesperetin with benzohydrazide (HHSB or LH), isoniazid (HIN or LH), or thiosemicarbazide (HTSC or LH) and their Cu complexes (CuHHSB, CuHIN, and CuHTSC with the general formula [CuLH(AcO)]) were evaluated in aqueous solution both experimentally and theoretically. UV-Vis studies indicate that the ligands and complexes exhibit hypochromism, which suggests helical ordering in the DNA helix. The intrinsic binding constants () of the Cu compounds with CT-DNA, in the range (2.3-9.2) × 10, from CuHTSC to CuHHSB, were higher than other copper-based potential drugs, suggesting that π-π stacking interaction due to the presence of the aromatic rings favors the binding. Thiazole orange (TO) assays confirmed that ligands and Cu complexes displace TO from the DNA binding site, quenching the fluorescence emission. DFT calculations allow for an assessment of the equilibrium between [Cu(LH)(AcO)] and [Cu(LH)(HO)], the tautomer that binds Cu, amido (am) and not imido (im), and the coordination mode of HTSC (O, N, S), instead of (O, N, NH). The docking studies indicate that the intercalative is preferred over the minor groove binding to CT-DNA with the order [Cu(LH)(AcO)] > [Cu(LH)(AcO)] ≈ TO ≈ LH > [Cu(LH)(AcO)], in line with the experimental constants, obtained from the UV-Vis spectroscopy. Moreover, dockings predict that the binding strength of [Cu(LH)(AcO)] is larger than [Cu(LH)(HO)]. Overall, the results suggest that when different enantiomers, tautomers, and donor sets are possible for a metal complex, a computational approach should be recommended to predict the type and strength of binding to DNA and, in general, to macromolecules.
Topics: DNA; Schiff Bases; Hesperidin; Copper; Coordination Complexes; Animals; Cattle; Ligands; Molecular Docking Simulation; Isoniazid; Semicarbazides
PubMed: 38791321
DOI: 10.3390/ijms25105283 -
Biomedicines May 2024Although blood still remains the most commonly utilized medium to detect increased levels of oxidative damage induced by exercise, saliva diagnostics have gained...
Although blood still remains the most commonly utilized medium to detect increased levels of oxidative damage induced by exercise, saliva diagnostics have gained increasing popularity due to their non-invasive nature and athlete-friendly collection process. Given that the contribution of various phases of the menstrual cycle to the levels of oxidative damage may differ, the aim of this study was to evaluate an agreement between salivary and plasmatic levels of lipid peroxidation products in female swimmers in both the follicular (F) and luteal (L) phases of the menstrual cycle at rest and following exercise. Twelve well-trained female swimmers aged 19.6 ± 1.1 years old were examined. We measured diene conjugates (DCs), triene conjugates (TCs), and Schiff bases (SBs) in lipids immediately after their extraction from both saliva and blood plasma. All female swimmers were studied two times each, in the two different phases of one menstrual cycle, before and after high-intensity interval exercise (HIIE). Salivary and plasmatic levels of DCs, TCs, and SBs significantly increased post-exercise compared to pre-exercise, in both the F and L phases. A high positive correlation was observed between the concentrations of DCs, TCs, and SBs in the saliva and blood plasma of participants in the F and L phases, both at rest and following HIIE. Ordinary least products regression analysis indicates that there was no proportional and differential bias in the data. The Bland-Altman method also declares that there was no differential bias, since the line of equality was within the 95% confidence interval of the mean difference between salivary and plasmatic levels of DCs, TCs, and SBs in female swimmers, in both the F and L phases, before and after HIIE. There was also no proportional bias in the Bland-Altman plots. Thus, this is the first study to report a high agreement between the quantifications of DCs, TCs, and SBs in the saliva and blood plasma of female swimmers in both the F and L phases, at rest and following HIIE.
PubMed: 38790968
DOI: 10.3390/biomedicines12051006 -
Nature Communications May 2024Ferroelectric materials, whose electrical polarization can be switched under external stimuli, have been widely used in sensors, data storage, and energy conversion....
Ferroelectric materials, whose electrical polarization can be switched under external stimuli, have been widely used in sensors, data storage, and energy conversion. Molecular orbital breaking can result in switchable structural and physical bistability in ferroelectric materials as traditional spatial symmetry breaking does. Differently, molecular orbital breaking interprets the phase transition mechanism from the perspective of electronics and sheds new light on manipulating the physical properties of ferroelectrics. Here, we synthesize a pair of organosilicon Schiff base ferroelectric crystals, (R)- and (S)-N-(3,5-di-tert-butylbenzylidene)-1-((triphenylsilyl)oxy)ethanamine, which show optically controlled phase transition accompanying the molecular orbital breaking. The molecular orbital breaking is manifested as the breaking and reformation of covalent bonds during the phase transition process, that is, the conversion between C = N and C-O in the enol form and C-N and C = O in the keto form. This process brings about photo-mediated bistability with multiple physical channels such as dielectric, second-harmonic generation, and ferroelectric polarization. This work further explores this newly developed mechanism of ferroelectric phase transition and highlights the significance of photo-mediated ferroelectric materials for photo-controlled smart devices and bio-sensors.
PubMed: 38789426
DOI: 10.1038/s41467-024-48405-y -
Chemical Science May 2024The pursuit of multifunctional electrocatalysts holds significant importance due to their comprehension of material chemistry. Amorphous materials are particularly...
The pursuit of multifunctional electrocatalysts holds significant importance due to their comprehension of material chemistry. Amorphous materials are particularly appealing, yet they pose challenges in terms of rational design due to their structural disorder and thermal instability. Herein, we propose a strategy that entails the tandem (low-temperature/250-350 °C) pyrolysis of molecular clusters, enabling preservation of the local short-range structures of the precursor Schiff base nickel (Ni[2(CHNNiO)]). The temperature-dependent residuals demonstrate exceptional activity and stability for at least three distinct electrocatalytic processes, including the oxygen evolution reaction ( = 197 mV), urea oxidation reaction ( = 1.339 V), and methanol oxidation reaction (1358 mA cm at 0.56 V). Three distinct nickel atom motifs are discovered for three efficient electrocatalytic reactions (Ni1 and Ni1' are preferred for UOR/MOR, while Ni2 is preferred for OER). Our discoveries pave the way for the potential development of multifunctional electrocatalysts through disordered engineering in molecular clusters under tandem pyrolysis.
PubMed: 38784754
DOI: 10.1039/d4sc01696c -
ACS Catalysis May 2024Photoactivated catalysts for the hydrosilylation of alkenes with silanes offer temporal control in manufacturing processes that require silicone curing. We report the...
Photoactivated catalysts for the hydrosilylation of alkenes with silanes offer temporal control in manufacturing processes that require silicone curing. We report the development of a range of air-stable Pt(II) (salicylaldimine)(phenylpyridyl), [Pt(sal)(ppy)], complexes as photoinitiated hydrosilylation catalysts. Some of these catalysts show appreciable latency in thermal catalysis and can also be rapidly (10 s) activated by a LED UV-light source (365 nm), to give systems that selectively couple trimethylvinylsilane and hexamethylsiloxymethylsilane to give the linear hydrosilylation product. Although an undetectable (by NMR spectroscopy) amount of precatalyst is converted to the active form under UV-irradiation in the timescale required to initiate hydrosilylation, clean and reliable kinetics can be measured for these systems that allow for a detailed mechanism to be developed for Pt(sal)(ppy)-based photoactivated hydrosilylation. The suggested mechanism is shown to have close parallels with, but also subtle differences from, those previously proposed for thermally-activated Karstedt-type Pt(0) systems.
PubMed: 38779183
DOI: 10.1021/acscatal.4c01353 -
RSC Advances May 2024In this study, boehmite nanoparticles (B-NPs) were prepared by a simple process and then their surface was modified by (3-aminopropyl)triethoxysilane (3-APTES). The...
A new Schiff base 2-benzoylpyridine-based copper complex on boehmite nanoparticles as a recoverable nanocatalyst for the homoselective synthesis of 5-substituted tetrazoles.
In this study, boehmite nanoparticles (B-NPs) were prepared by a simple process and then their surface was modified by (3-aminopropyl)triethoxysilane (3-APTES). The modified B-NPs (3-APTES@B-NPs) were functionalized by 2-benzoylpyridine Schiff-base ligand toward the immobilization of the Schiff-base 2-benzoylpyridine ligand on the 3-APTES@B-NPs's surface (2BP-Schiff-base@B-NPs). Finally, copper ions were coordinated with the supported Schiff-base ligand on B-NPs toward the formation of the final catalyst (Cu-2BP-Schiff-base@B-NPs). The prepared Cu-2BP-Schiff-base@B-NPs were characterized using FT-IR spectroscopy, BET analysis, XRD, SEM, AAS, TGA, EDX and elemental mapping. Further, Cu-2BP-Schiff-base@B-NPs were applied as a homoselective and recyclable catalyst for the synthesis of a diverse range of 5-substituted tetrazoles in PEG-400 as a green solvent. The main benefits of this protocol are high homoselectivity attributes, short reaction times, high product yields and TOF values, and further addition to the catalyst ability to be recycled at least four times without significantly losing catalytic efficiency.
PubMed: 38769959
DOI: 10.1039/d4ra03139c -
Carbohydrate Polymers Aug 2024The dynamic interplay between cells and their native extracellular matrix (ECM) influences cellular behavior, imposing a challenge in biomaterial design. Dynamic...
The dynamic interplay between cells and their native extracellular matrix (ECM) influences cellular behavior, imposing a challenge in biomaterial design. Dynamic covalent hydrogels are viscoelastic and show self-healing ability, making them a potential scaffold for recapitulating native ECM properties. We aimed to implement kinetically and thermodynamically distinct crosslinkers to prepare self-healing dynamic hydrogels to explore the arising properties and their effects on cellular behavior. To do so, aldehyde-substituted hyaluronic acid (HA) was synthesized to generate imine, hydrazone, and oxime crosslinked dynamic covalent hydrogels. Differences in equilibrium constants of these bonds yielded distinct properties including stiffness, stress relaxation, and self-healing ability. The effects of degree of substitution (DS), polymer concentration, crosslinker to aldehyde ratio, and crosslinker functionality on hydrogel properties were evaluated. The self-healing ability of hydrogels was investigated on samples of the same and different crosslinkers and DS to obtain hydrogels with gradient properties. Subsequently, human dermal fibroblasts were cultured in 2D and 3D to assess the cellular response considering the dynamic properties of the hydrogels. Moreover, assessing cell spreading and morphology on hydrogels having similar modulus but different stress relaxation rates showed the effects of matrix viscoelasticity with higher cell spreading in slower relaxing hydrogels.
Topics: Hyaluronic Acid; Hydrogels; Humans; Fibroblasts; Schiff Bases; Cross-Linking Reagents; Biocompatible Materials; Extracellular Matrix; Cells, Cultured
PubMed: 38763720
DOI: 10.1016/j.carbpol.2024.122173