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In this work, Schiff bases of 4-methoxybenzyl amine and hydrazide derivatives containing succinic (BMSHE), oxalyl (BMOHE), and phenylaceto (BMPHE) have been synthesized and applied for corrosion inhibition of mild steel (MS) in 1.0 M HCl. The synthesized compounds are characterized by Fourier-transform infrared (FTIR) and H1 nuclear magnetic resonance (NMR) spectroscopy. The FTIR and H1 NMR results have confirmed their formation through the presence of functional groups and hydrogen associated with them. Corrosion mitigation examination is done by polarization measurements (PM), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) equipped with energy dispersive X-rays (EDX), and atomic force microscopy (AFM). All inhibitors demonstrated notable efficacy in preventing MS in HCl (BMSHE-88%, BMOHE-84%, and BMPHE-72%). As per corrosion potentials, BMOHE and BMPHE have been found to be mixed types of inhibitors, and BMSHE is noticed as a cathodic inhibitor. The SEM results demonstrated how these hydrazide derivatives prevented corrosion by covering the MS surface. The EDX analysis of the surfaces has revealed that the inhibited MS contains lower amounts of O and Cl, which indicate that the inhibitors prevent MS in HCl. AFM analysis shows that the surfaces of MS in the presence of the inhibitors are damaged less than in their absence, which reveals the same facts as told above. The inhibition of MS by BMSHE, BMOHE, and BMPHE is also explained with a reason after analyzing the results. [ABSTRACT FROM AUTHOR]

Aromatic compounds containing hydroxyl groups in their structure are converted to oligomer or polymer products from the combination of phenoxy-structured radical units in the presence of oxidants such as O2, H2O2 and NaOCl in alkaline or acidic aqueous media. These macromolecule compounds are used in many fields in industry because they contain both phenyl units and different functional groups in their structures. Since the phenyl units in the main chain give rigidity to the structure, the thermal stabilities of these types of polymers are quite good. Schiff base compounds were obtained as a result of the condensation reaction of 4-hydroxy-3-methoxybenzaldehyde, 2-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 5-bromsalicylaldehyde and 2-hydroxy-1-naphthaldehyde compounds with 2,4-diamino-6-phenyl-1,3,5-triazine as amine. Oligo(phenoxy-imine)s were synthesized from Schiff bases by oxidative polycondensation in the presence of O2 oxidant in aqueous alkaline medium. The structural characterizations of Schiff bases and oligo(phenoxy-imine)s were performed by FT-IR, 1H-NMR, 13C-NMR and UV–Vis analyses. Electrochemical band gap ( E g ′ ) values of monomers and oligomers were calculated from CV measurements. The E g ′ values of FMD, FMB, FMM, FMF, FMN, OFMD, P-FMB, OFMM, OFMF and OFMN were calculated to be 2.80, 2.63, 2.52, 2.76, 2.12, 2.57, 2.49, 2.44, 2.51 and 2.07 eV, respectively. Limit oxygen index values of OFMD, P-FMB, OFMM, OFMF and OFMN were calculated to be 33.46%, 38.85%, 38.43%, 44.86% and 23.46%, respectively. Also, the molecular weight distributions, glass transition temperature (Tg) and surface images of oligomers were determined from GPC, DSC and SEM measurements, respectively. [ABSTRACT FROM AUTHOR]

The structural and electronic behavior of thiosemicarbazone (TSC)-based metal complexes of Mn (II), Fe (II), and Ni (II) have been investigated. The synthesized metal complexes were characterized using elemental analysis, magnetic susceptibility, molar conductivity, FTIR, and UV–Vis spectroscopy, the computational path helped with further structural investigation. The solubility test on the TSC and its complexes revealed their solubility in most organic solvents. DFT computational analysis was performed, and quantum reactivity parameters of the octahedral optimized complexes were calculated to describe the reactivity via the stability states of the synthesized complexes. FMOs map was generated to confirm similar findings and MEP analysis was applied to elaborate the important electrophilic and nucleophilic sites on the studied surfaces. Also, other important topological analyses such as electron localization function and reduced density gradient, to establish the favorable noncovalent interactions, were studied. In silico molecular docking approach was studied against the gram-positive bacteria Bacillus cereus to predict the potent inhibition behavior of the studied complexes. The findings summarized the inhibition prediction of the most interactive [NiL2Cl2], then [FeL2Cl2] complexes as confirmed by the binding energy values (− 7.1 kacl/mol and − 6.4 kacl/mol, respectively). Another In silico results, with gram-positive bacteria (S. aureus), estimated similar results of the experimental finding, where [MnL2Cl2] (− 9.2 kcal/mol) is the more effective predicted antibacterial inhibitor. Fluorescence microscopy was used to examine the inhibition of bacterial biofilm, and the DPPH assay was used to measure antioxidant activity, followed by an understanding of the behavior of the current complexes toward free radicals' removal. The findings observed less aggregated bacterial strains covered with the studied complexes leading to less dense biofilm covering. [ABSTRACT FROM AUTHOR]

AbstractThree chlorinated metal complexes [Ni2(HL)2(C2H5OH)2Cl2]·2C2H5OH (complex 1), [Co(HL)(L)] (complex 2), and [Zn2(HL)2(CH3COO)2] (complex 3) derived from 5-chlorosalicylaldehyde and 2-(2-aminophenyl)-1H-benzimidazole Schiff base ligand (H2L). The crystal structures of the three complexes were characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, X-ray single-crystal diffraction, and UV-visible absorption spectrum. The in vitro cytotoxicity of chlorinated ligand and its metal complexes were evaluated on four different tumor cell lines (A-549 lung cancer, SMMC-7721 liver cancer, MDA-MB-231 breast cancer, and CNE-2Z nasopharyngeal carcinoma), and normal ovarian epithelial cell (IOSE 80) was determined by MTT assay. The results indicated that chloro-benzimidazole Schiff base Co (III) complex (complex 2) displayed higher cytotoxicity against MDA-MB-231 cell line than cisplatin, while the cytotoxicity on IOSE 80 was lower than that of cisplatin. The results of further study of MDA-MB-231 cells by complex 2 showed that complex 2 could inhibit MDA-MB-231 cells in the G0/G1 phase, inhibit cell proliferation and migration, promote cell apoptosis, and increase intracellular ROS level. The Western blot analysis demonstrated that complex 2 could increase Bax protein expression and decrease Bcl-2 protein expression in MDA-MB-231 cells. [ABSTRACT FROM AUTHOR]

AbstractOne new sulfoxide-containing Schiff base, (E)-4-chloro-2-((2-(methylsulfinyl phenyl)imino)methyl) phenol (HL) was coordinated with ruthenium and rhodium, affording five ruthenium(II) complexes [RuCl(L)(CO)2] (1), [RuCl(L)(dmso)2] (dmso = dimethylsulfoxide, 2), [RuCl(L)(PPh3)(CH3CN)] (3), [RuCl(L)(CO)(PPh3)] (4), [RuCl(NOS-LH2)(CO)(PPh3)] (5) and one rhodium(IV) complex [RhCl3(L)] (6). Molecular structures of HL and complexes 1–6 were established by single crystal X-ray diffraction analysis. Moreover, the free ligand HL and its complexes 1–6 were characterized by infrared, NMR, UV-vis, and fluorescence spectroscopies, and their electrochemical properties were also investigated. The ruthenium complexes showed good catalytic activity for the cyclopropylation of styrene. [ABSTRACT FROM AUTHOR]

Nickel complexes are a potential candidate for antibacterial and antifungal activity. A new Ni (II) complex, bis(2-methoxy-6-{[(2-methylpropyl)imino]methyl}phenolato)nickel (II) (2), was synthesised by reacting, bis(3-methoxy-salicylaldehyde)nickel (II) (1) with isobutylamine. It was characterised by single crystal X-ray diffraction (ScXRD), UV-Vis, NMR, IR, mass spectrometry, and thermogravimetry (TG) to study its structure and physico-chemical properties. The ScXRD showed a square planar geometry, and monoclinic crystal system with a space group P21/n. The TG analysis revealed its thermal durability pre and post-melting up to 225 oC with a weight loss of only 2%. The optimized molecular structure, energy gap between HOMO and LUMO, and intermolecular interactions were studied by computational methods. The microbial activity evaluation showed significant anti-bacterial activity against E. coli and S. aureus when the concentration exceeded 40 µg/mL, and a prominent anti-fungal activity over C. albicans and C. tropicalis above 30 µg/mL. The values of minimum inhibitory concentration (MIC) for bacteria (MIB) and fungi (MIF) implied its potential to inhibit the growth of microbes. Docking studies revealed that the molecule binds well with proteins such as PDB: 2W9H for Dihydrofolate Reductase of S.aureus as shown by its binding energy of -8.62 kcal.mol− 1. [ABSTRACT FROM AUTHOR]

AbstractThis article presents a new and facile method for the synthesis of Schiff base compounds with a benzimidazole group using a low-cost and reusable calcium aluminate nanophosphorus catalyst (CaAl2O4). This approach avoids harmful solvents and reactants, supporting a more environmentally friendly synthesis process. The catalyst maintained its activity and heterogeneity over four cycles with minimal loss of efficiency. The synthesis process was straightforward and eliminated the need for column chromatography. The Schiff base ligand (HL=(E)-N-((6-(thiophen-2-yl)pyridin-2-yl)methylene)-1H-benzo[d]imidazol-2-amine)) was synthesized by the reaction of 6-(thiophen-2-yl)pyridine-2-carbaldehyde with 1H-benzimidazole-2-amine. Subsequently, metal(II) complexes of Co(II), Ni(II), and Cu(II) were prepared using this ligand. Structural analysis of both the ligand and its metal complexes was carried out using various physicochemical and spectroscopic methods. Ni(II) and Co(II) complexes were found to adopt an octahedral geometry, while the Cu(II) complex exhibited a square-planar structure. Binding studies with calf thymus DNA (CT-DNA) at pH 7.2 were performed using UV-visible spectroscopy, viscosity measurements, and thermal denaturation studies and showed that the metal complexes intercalate into the DNA and produced a distinct binding pattern. Molecular docking simulations with AutoDock Vina provided insights into the interaction of these complexes with the B-DNA dodecamer. Furthermore, the ligand and its metal complexes showed UV-visible photonuclease activity against pUC19 DNA. Agarose gel electrophoresis showed that the metal complexes exhibit photoinduced nuclease activity, confirming their ability to cleave DNA upon exposure to light. [ABSTRACT FROM AUTHOR]

A novel chromone-based Schiff base L was designed and synthesized by condensing an equimolar amount of 3-formyl chromone and 2,4-dinitro phenyl hydrazine. Schiff base L was developed as a potent colorimetric and fluorescent molecular probe to recognize Hg2+ ions over other competitive metal ions. In the presence of Hg2+, Schiff base L displays a naked-eye detectable color change under day and UV365 nm light. Various UV-Vis and fluorescence studies of L were performed in the absence and presence of Hg2+ to determine the sensitivity and the sensing mechanism. With high selectivity and specificity, the detection limit and association constant of L for Hg2+ were estimated at 1.87 µM and 1.234 × 107 M−1, respectively. The developed sensor L was applied to real soil samples for the detection of Hg2+. [ABSTRACT FROM AUTHOR]

This review basically concerned with the application of different Schiff bases (SB) based fluorimetric (turn-off and turn-on) and colorimetric chemosensors for the detection of heavy metal cations particularly Al(III), Fe(III), and Cr(III) ions. Chemosensors based on Schiff bases have exhibited outstanding performance in the detection of different metal cations due to their facile and in-expensive synthesis, and their excellent coordination ability with almost all metal cations and stabilize them in different oxidation states. Moreover, Schiff bases have also been used as antifungal, anticancer, analgesic, anti-inflammatory, antibacterial, antiviral, antioxidant, and antimalarial etc. The Schiff base also can be used as an intermediate for the formation of various heterocyclic compounds. In this review, we have focused on the research work performed on the development of chemosensors (colorimetric and fluorometric) for rapid detection of trivalent metal cations particularly Al(III), Fe(III), and Cr(III) ions using Schiff base as a ligand during 2020-2022. [ABSTRACT FROM AUTHOR]

In this study, we have synthesized a novel Schiff base-centered chemosensor, designated as SB, with the chemical name ((E)-1-(((6-methylbenzo[d]thiazol-2-yl) imino)methyl)naphthalen-2-ol). This chemosensor was structurally characterized by FT-IR, 1H NMR, UV-Vis and fluorescence spectroscopy. After structural characterization the chemosensor SB was subsequently employed for the detection of Cu2+ and Ag+, using fluorescence spectroscopy. The chemosensor SB showed excellent ability to recognize the target metal ions, leading to fluorescence enhancement and color change from yellow to yellowish orange for Cu2+ and yellow to radish for Ag+ ions. The detection capabilities of this chemosensor were impressive, showing excellent selectivity and an exceptionally low detection limit of 0.0016 µM for Cu2+ and 0.00389 µM for Ag+. Most notably, our approach enables the quantitative detection both metal ions in different water and soil samples at trace level. This achievement holds great promise for analytical applications and offers significant contributions to the field of chemical sensing and environmental protection. [ABSTRACT FROM AUTHOR]

The design and development of novel efficient fluorescent chemical sensors for the selective detection of ions is currently of significant importance in supramolecular chemistry. Since zinc is a ubiquitous, indispensable and the second most abundant metal ion in the human body, developing chemosensors that can accurately discriminate between Zn2+ and Cd2+ ions has been a challenge due to their similar properties as they are in the same group of the periodic table. Therefore, a technique to trace and visualize free zinc ions is demanded. In this study, an innovative coumarin-based Schiff base (L) was synthesized and characterized by 1H NMR, 13C NMR and mass spectroscopy. A novel "Turn On" fluorescence chemosensor platform was developed for trace amounts of Zn2+ ions. The fluorescence Job's plot measurement was used to determine the complexation ratio between the probe and Zn2+ ion, which showed a maximum point indicating the formation of a ML2 adduct. Additionally, the geometrical parameters calculated using DFT and TD-DFT calculations were in close agreement with the experimentally observed values. [ABSTRACT FROM AUTHOR]

N4-donor Schiff base copper(II) nanoparticles were easily prepared through surface modification of silica-coated magnetite nanoparticles (Fe3O4@SiO2) with pyrrole 2-carbaldehyde Schiff base and a subsequent reaction with Cu(CH3COO)2.H2O in ethanolic solution. This nanocatalyst was characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and magnetization. Efficient oxidation of alkenes and alcohols was carried out over the Schiff base copper(II) nanoparticles. Catalytic tests showed that the catalyst was particularly effective for the oxidation of α-methyl styrene, norbornene, benzyl alcohol, and benzohydrol. The results showed that acetophenone, 2-norbornanone, benzoic acid, and benzophenone with selectivity values of 88, 100, 100, and 100, respectively, were obtained. The heterogeneous catalyst of N4-donor Schiff base copper(II) offers advantages such as ease of product separation, catalyst recycling, and ease of preparation. Antibacterial tests against two gram-positive and two gram-negative bacterial species found that the bacteria stopped growing in the catalyst medium. HIGHLIGHTS: A novel nanomagnetic heterogeneous catalyst of N4-donor Schiff base copper(II) immobilized on superparamagnetic Fe3O4@SiO2 was Synthesized. Catalyst was characterized by TGA, XRD, FT-IR, TEM, and magnetization. Fe3O4@SiO2@APTMS@PYC@Cu was used as an efficient nanocatalyst for oxidation of alkenes and alcohols. Nano-catalyst antibacterial studies were performed. The catalyst has high catalytic capability, excellent magnetic separately, and reusability. [ABSTRACT FROM AUTHOR]

A simple salicylaldehyde-based Schiff base 2,2'-((1,3-phenylenebis(azanylylidine))bis(methanylylidene))dipehnol (PAMD) was synthesised by condensation reaction between salicylaldehyde and benzene-1,3-diamine (2:1 ratio) and characterised by spectral techniques such as NMR, FTIR and HRMS, followed by investigation for its spectroscopic behaviour towards diverse metal ions using UV and fluorescence studies. PAMD was found to exhibit sensitivity towards Cu2+ only. The receptor PAMD was then explored for its electrochemical behaviour using cyclic voltammetry, which displayed an irreversible anodic peak at 1.00 V due to imine group. Furthermore, PAMD was subjected to differential pulse voltammetry, which exhibited a sensitive response for Cu2+ in the linear range of 0–3.8 μM with lowest detection limit of 0.03 μM. The complexation between PAMD and Cu2+ was also supported by large values of binding constant (1.3 × 105 M−1) and negative free energy change (ΔG∘ = -29.2 kJmol−1) obtained from Benesi–Hildebrand equation. The carbon paste electrode (CPE) modified with PAMD displayed a Nernstian response to Cu2+ in the concentration range from 1.0 × 10−6 to 1.0 × 10−1 M and lowest detection limit of 4.0 × 10−7 M. The PAMD-CPE was successfully applied for determination of Cu2+ content in real samples such as groundwater, soil, and food grains (wheat and rice). [ABSTRACT FROM AUTHOR]

In our previous study, Schiff base (1) complexes derived from 2,3‐diaminophenazine and metal ions Co(II) (2), Ni(II) (3), Cu(II) (4), and Cd(II) (5) were synthesized and characterized, demonstrating a significant biological activity. This study investigates their anticancer potential, specifically against prostate cancer. The complexes exhibited notable reductions in cancer cell viability, with IC50 values of 0.531 μM Ni(II), 0.630 μM Cu(II), and 0.655 μM Co(II), comparable with the standard drug enzalutamide. The Co(II) complex showed the highest efficacy, while Cd(II) displayed the lowest (IC50 = 0.648 μM). The presence of a phenazine ring in these complexes enhances DNA binding, contributing to their anticancer effects. HOMO‐LUMO calculations revealed energy gaps ranging from 2.525 to 3.294 eV, indicating varying reactivity and potential for biological interactions. Molecular docking studies revealed that compound (1) exhibited the highest binding affinity (−9.19 kcal/mol) for the prostate cancer‐related receptor, with significant hydrogen bond interactions. Molecular dynamics simulations over 100 ns demonstrated stable binding, with RMSD values below 1.5 Å, and RMSF analysis provided insights into protein flexibility. ADMET studies revealed favorable drug‐like properties, including good gastrointestinal absorption (> 30%), high blood–brain barrier permeability (LogBBB = 0.64), and high human intestinal absorption (68.47%–88.79%). No inhibition of CYP2D6 was observed, suggesting low risk for drug–drug interactions. These Schiff base‐metal complexes show promising anticancer activity and favorable ADMET profiles, indicating their potential as therapeutic agents for prostate cancer treatment. [ABSTRACT FROM AUTHOR]

Cancer, a leading cause of death globally, necessitates clinical research to develop effective solutions to reduce mortality rates. Currently, scientists are focusing on two prominent topics in cancer treatment: the presence of Sn2+ in cells and the inhibition of the phosphoinositide 3‐kinase enzyme (PI3Kα). In this study, Schiff base‐coupled silane 7a {C26H35N5O6Si (M + H+ = 540.53)} has been synthesized that could detect Sn2+, which in trace amounts can help prevent cancer, and it also inhibits PI3Kα enzyme, thereby preventing the rapid proliferation of cancer cells. The detection limit and binding constant calculated via Fluorescence studies were found to be 3.46 × 10−8 M and 9.4 × 104 M−1, respectively. The value of inhibition constant of silane for PI3Kα enzyme was also found to be 2.52 nM via molecular docking. [ABSTRACT FROM AUTHOR]

The azine‐based bismuth (III) complex [Bi(H2L1)(NO3)3(H2O)2]•H2O(1a) was synthesized by an equivalent reaction between Schiff base and Bi (NO3)3•5H2O using mannitol as an auxiliary agent. During the formation of the complex (1a), the Schiff base containing 3‐methoxy group transformed into 3‐methoxysalicylaldehyde azine and further coordinated with BiIII ion to form a mononuclear BiIII complex (1a). Bismuth (III) ions were unexpectedly found to catalyze the formation of the azines from Schiff bases derived from pyrazinohydrazide, and their formation mechanism was further studied. Theoretical studies of the complex (1a) involving thermodynamic and electronic properties were done using the density functional theory (DFT) B3LYP method. Furthermore, in vitro biological evaluation showed that the antimicrobial and cytotoxic activities of the complex (1a) were much higher than those of free ligands. The obtained MIC and IC50 values of the complex (1a) were almost close to those of the reference drugs. [ABSTRACT FROM AUTHOR]

Schiff bases are introduced as versatile pharmacophores for the design and development of various bioactive compounds. Oxime‐based Schiff base ligands form an important and flexible class of ligands that have attracted attention due to their wide applications in various fields. Here, novel 3‐(2‐hydroxyphenyl‐imino)butan‐2‐one oxime, (HPIO) Schiff base and Zn(II) complexes derived from it, [Zn(bpy)(HPIO)](NO3)2, C1, (bpy = 2,2′‐bipyridine) and [Zn(HPIO)2]Cl2, C2, were synthesized and characterized. Theoretical studies showed that both complexes are reactive and have high pharmacological affinity. Experimental investigations were done to compare some biological properties of the complexes. Antioxidant studies using ·DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) assay presented the following trend: C1 > C2 > HPIO. Considering the importance of the antioxidant enzyme catalase in removing reactive oxygen species (ROS), the binding process of C1/C2 with catalase was evaluated. Kinetic studies showed that C1/C2 can inhibit the catalytic performance of catalase by mixed‐type inhibition mechanism. The C1 and C2 quenched the catalase fluorescence emission with static quenching mechanism. The binding affinity to catalase was higher for C1 than C2 (Kb = 1.51 and 0.89 × 105 M−1 for C1 and C2, respectively at 305 K). In C1/C2 interaction with catalase, which was an exothermic and spontaneous process, hydrogen bonds, van der Waals forces, and hydrophobic interactions played a decisive role and strongly confirmed by molecular docking data. Tracking the structural changes of catalase showed that enzyme undergoes structural changes in the presence of both complexes. [ABSTRACT FROM AUTHOR]

Novel three metal complexes were synthesized starting from the selenated Schiff base 2‐(((4‐(benzylselanyl)phenyl)imino)methyl)‐5‐nitrophenol (BnSeOH) ligand. Elements, spectral data, magnetic moment, molar conductance, and thermal gravimetric investigations were used to confirm their structures, as well as X‐ray diffraction, IR, NMR, and MS spectroscopic techniques. Octahedral geometry was proposed for the Fe (III), Cu (II), and Zn (II) complexes. The anticancer and antimicrobial activities were assessed against various mammalian cells and pathogenic strains. Within this context, the Fe (III) complex and BnSeOH ligand were the most cytotoxic, and their toxicity was more pronounced in the case of HepG2 cells. Likewise, the Fe (III) complex and BnSeOH ligand showed good antimicrobial activity against Candida Albicans, Bacillus subtilis, and Pseudomonas aeruginosa pathogens. Furthermore, the antioxidant properties were also estimated using DPPH and SOD bioassays. Computational analysis revealed the ligand exhibits lower reactivity relative to its metal complexes based on the ΔE gap and η values representing energy gap and hardness. The parameters examined in this study provide valuable insight into the bonding, electronic properties, reactivity, and polarity of the compounds under investigation. The pharmacological and computational findings point to promising activities of complexes. [ABSTRACT FROM AUTHOR]

Herein, a new hybrid inorganic–organic ligand was designed and synthesized to form a series of transition metal (II) complexes as potential substrate towards cytotoxicity studies. The inorganic heterocycle, cyclotriphosphazene (N3P3Cl6, CTP) was chosen as the core unit to synthesize geminal hydrazone Schiff bases as multisite coordination ligand via substitution of six reactive chlorine. Herein, CTP was substituted by nucleophilic reaction at six chlorine atoms that exist on three phosphorus (V) centers of CTP with salicylaldehyde to form hexakis salicylaldehyde derivative. Further, salicylic hydrazide tethered with terminal amine group was condensed with above hexakis salicylaldehyde derivative of CTP at ratio of 1:6 afforded SBCTP ligand. Indeed, a series of M (II) complexes (M = Co, Ni, Mn, Cu and Zn) were obtained from SBCTP ligand with characteristic functional groups to manifest the cytotoxic activity, in order to venture as the active anticancer agent in pharmaceutics. Despite the Schiff base of aromatic rings tend to exhibit inherent cytotoxic properties, the complementary influence of CTP appended with two consecutive salicylic units in SBCTP found to show unique properties. In particular, metal (II) complexes via imine bonds of SBCTP oriented from CTP ring found to reveal essential properties to treat cancerous cells. The above ligand and prospective metal complexes were investigated individually for the cytotoxic activity with normal and cancerous cells at five different concentrations, with/without addition of the above samples into MTT assay. Structural characterization of above samples was conducted by multinuclear NMR, 1H, 13C, and 31P as well as ESI, HRMS, FTIR, EDS, and TGA data. [ABSTRACT FROM AUTHOR]

A new Schiff base ligand, HNMPC, was prepared and reacted with some metal ions, including Cu(II), Ni(II), Co(II), Mn(II), and VO(IV). The infrared, electronic, mass, electron spin resonance, nuclear magnetic resonance, thermal and elemental analysis, molar conductance, and magnetic susceptibility measurements were used to characterize the metal complexes. The HNMPC ligand acts as a monoanionic tridentate ONO donor in all complexes, and the coordinating sites are C=Opyridone, C=N, and the phenolate anion. All metal complexes exhibit octahedral configurations, and the results showed that the metal ion:ligand ratio was 1:2. The molecular structural parameters of the ligand and its metal complexes were determined based on the DFT level implemented in the Gaussian 09 program B3LYP/GENECP method at the 6‐311G(d,p) basis set for C, H, N, and O atoms and the SDD (Stuttgart/Dresden) basis set for the metal atoms. The theoretical data were correlated with the experimental results. Gram‐positive bacteria, Gram‐negative bacteria, yeast, and fungi were used to test the current compounds' antimicrobial activity. Investigating the antitumor activity of the ligand and its complexes against the HepG2 cell lines showed encouraging IC50 values that were on par with those of cisplatin. In order to determine the affinity and binding pattern for the synthesized compounds toward the VEGFR‐2 active site, molecular docking studies were conducted, and the results were correlated with antitumor data. Based on the obtained results, future work aimed to synthesize a new category of Schiff bases and their metal complexes derived from the current aminopyridine derivative with diverse aldehydes and ketones. [ABSTRACT FROM AUTHOR]

Dihydroxy derivative of vanillin-based diaminotriazole core monomer (DTV) has been synthesized using sustainable vanillin (V) and 3,5-diamino-1,2,4-triazole (DT) under appropriate experimental conditions and characterized with a view to develop Schiff base core nitrogen-rich benzoxazines capable of exhibiting excellent optical and anti-microbial properties. The monomer DTV has been subsequently converted into benzoxazines separately using six structurally varied amino compounds, viz. aniline (a), 1-(−2-aminoethyl)piperazine (aep), furfurylamine (ffa), 4-H-1,2,4-triazoal-4-amine (ta), 3-aminopyrazol (apy) and 1-(3-aminopropyl)imidazole (api) with paraformaldehyde through Mannich condensation. The corresponding Schiff base based benzoxazines, viz. DTV-a, DTV-aep, DTV-ffa, DTV-ta, DTV-apy and DTV-api were synthesized and characterized for their molecular structure, thermal stability, optical, hydrophobic and anti-microbial properties using different analytical techniques and methods. Data obtained from different analyses for DTV based benzoxazines can be used for wide range of industrial and engineering applications. [ABSTRACT FROM AUTHOR]

Context: Isatin-Schiff bases have wide applications in chemistry. The π conjugated electronic system and heterocylic structure of these materials make them valuable for use as photosensitized materials. The delocalization of π-electrons throughout the structure causes the UV–vis absorption spectra to shift to longer wavelengths. In this study, the isatin manganese carbonyl complex shifted the UV–vis absorption wavelength to a longer wavelength (vis. 400–700 nm) compared with our previous studies. The isatin derivatives (ISE (3[4-ethyl(phenyl)imino][indoline-2-one]), ISB (3[4-butly(phenyl)imino][indoline-2-one])) and their Mn carbonyl complexes MnISE ((ISE)Mn(CO)3), and, MnISB ((ISB)Mn(CO)3) were investigated via density functional theory (DFT) in different solvent media. The most stable complexes were found in medium polarity THF. The calculated HOMO–LUMO energy gap shows that the charge transfer occurs within the molecule. The HOMO–LUMO energy gap was increased with increasing solvent polarity for all investigated compounds. The smaller energy gap indicates that charge transfer occurs within the Mn(II) complex, in contrast to ISE and ISB, which exhibit larger energy gaps. As a result, the maximum absorption of Mn complexes shifts to the visible region. MnISB has the smallest HOMO–LUMO energy gap in THF. Additionally, the global reactivity parameters indicated that the MnISE complex has the highest electrophilicity index. DFT calculations have also been performed to investigate polarizability and first-order hyperpolarizability of these compounds. In water, the ISE had higher NLO values than the other structures did. These results indicate that all the studied molecules in different solvents could be good candidates for use in photosensitized and nonlinear optical materials. Methods: Geometries were determined at the DFT level via the LANL2DZ basis set for Mn and cc-PVTZ for other atoms in the molecules with the B3LYP functional. The UV–vis absorption spectra and HOMO–LUMO energies of ISE, ISB, and their Mn complexes were calculated by Time-dependent DFT (TDDFT) with CAM-B3LYP using the same basis sets. The UV–vis absorption spectra of ISE were also measured in acetonitrile and compared with the calculated spectra, which were consistent with the experimental results. All calculations were repeated in different solvents with the polarizable continuum model (PCM). [ABSTRACT FROM AUTHOR]

A new Schiff base, paeonol-[1,4-bis(3-aminopropyl)piperazine], was synthesized for the first time by the condensation reaction of paeonol and 1,4-bis(3-aminopropyl)piperazine through solution method. The product was characterized by the methods of melting point, IR, UV-Vis, fluorescence spectrum, 1H NMR, elemental and thermal analysis, and its crystal structure was analyzed by single crystal X-ray diffraction method, which indicated that it belongs to triclinic system, group, a = 6.836(14) Å, b = 7.729(17) Å, c = 12.28(3) Å, α = 87.25(2)°, β = 85.53(2)°, γ = 88.74(2)°. The antioxidant and in vitro antibacterial activities of the product were investigated by DPPH method and agar plate diffusion method, respectively. Moreover, the interaction of the product with biomacromolecule DNA was studied by the electronic spectroscopy and viscosity method. [ABSTRACT FROM AUTHOR]

Cu(II) complexes of three Schiff bases were synthesized and characterized via X-ray diffraction, Fourier transform infrared, and UV–vis spectroscopies. The Schiff bases act as bidentate ligands, chelating Cu(II) ions in seesaw coordination geometry. Changing the substituent types and positions creates various non-covalent interactions within the crystal packings, yielding notable topological differences. GC–MS analysis reveals that Cu(II) complexes induce 1.38%–11.43% efficacy in Suzuki–Miyaura cross-coupling reactions. The biological activity of complexes correlates with substituent type and position in the aromatic ring. The one with ethoxy exhibits antimicrobial effects solely against Candida parapsilosis, while those with fluorine enhance the activity, particularly in the meta position. [ABSTRACT FROM AUTHOR]

The oxidation of 5-HMF to HMFCA is an important yet complex process, as it generates high-value chemical intermediates. Achieving this transformation efficiently requires the development of non-precious, highly active catalysts derived from renewable biomass sources. In this work, we introduce UoM-1 (UoM, University of Mazandaran), a novel cobalt-based metal-organic framework (Co-MOF) synthesized using a simple one-step ultrasonic irradiation method. The synthesis employed the ligand 4,4'-((1E,1'E)-((5-carboxy-1,3-phenylene)bis(azaneylylidene))bis (methaneylylidene))dibenzoic acid (H3bdda). A comprehensive suite of analytical techniques, including FT-IR, EDX, ICP, XRD, TEM, DLS, FESEM, and BET-BJH, was used to confirm the structural integrity of the synthesized material. The catalytic performance of UoM-1 was investigated for the selective conversion of HMF to HMFCA, demonstrating its effectiveness as a low-cost, accessible catalyst. To promote a more sustainable and environmentally friendly approach, the oxidation reactions were performed in deep eutectic solvents, which offer a green, low-energy alternative to traditional solvents. This study shows that the UoM-1 catalyst not only provides an economical solution but also aligns with modern green chemistry principles, making it a highly promising candidate for future catalytic applications. [ABSTRACT FROM AUTHOR]

Multicolor emissive Schiff base lanthanide Poly(methyl methylacrylate) [PMMA] composite films are fabricated for white light generation. Three isostructural lanthanides (III) complexes [EuIII2(L)2(NO3)2(dmf)2 (1), TbIII2(L)2(NO3)2(dmf)2 (2) and GdIII2(L)2(NO3)2(dmf)2 (3)] are synthesized, characterized from the ligand obtained by 1:1 condensation of salicylaldehyde and 2‐(2‐Aminoethoxy)ethanol, H2L. The photoluminescent studies revealed pure blue, green, and red color emissions from GdIIIL, TbIIIL, and EuIIIL complexes, although the central metal centers have identical dodecahedron geometry. Intensified ligand emission  is attested for the blue emitter‐GdIIIL complex while the “antenna effect” is witnessed for green TbIIIL and red EuIIIL complexes. Co‐doping these multicolor luminescent emitters into the PMMA polymer the intensity of luminescence improved. A conscientious combination of red‐EuIIIL with green‐TbIIIL Lanthanide metal Schiff base complexes in a specified concentration, distinct white light is accomplished for the first time with Commission Internationale de I’Éclairage (CIE) values of 0.33, 0.30, very close to the ideal white emitter. The newly developed lanthanide‐Schiff base‐PMMA composite films are transparent and highly desired materials in optoelectronics, microscopy, and sensing. [ABSTRACT FROM AUTHOR]

Reaction of the phenolate or naphthalen‐2‐olate based Schiff base ligands, (E)‐1‐((2‐ethylphenylimino)methyl)phenol (HL1) or (E)‐1‐((2‐ethylphenylimino)methyl)naphthalen‐2‐ol (HL2) with nickel(II) and copper(II) acetate provides the complexes bis[(E)‐1‐((2‐ethylphenylimino)methyl)phenolato‐ĸ2N,O]Ni/Cu(II), [Ni(L1)2] (1) and [Cu(L1)2] (2), or bis[(E)‐1‐((2‐ethylphenylimino)methyl)naphthalen‐2‐olato‐ĸ2N,O]Ni/Cu(II), [Ni(L2)2] (3) and [Cu(L2)2] (4), respectively. Single crystal X‐ray structure determinations for 1, 3 and 4 reveal N2,O2‐metal coordination of two chelating Schiff base ligands in a square‐planar geometry. Powder X‐ray diffractograms confirm the phase purity of the bulk microcrystalline samples. Thermal analyses by differential scanning calorimetry (DSC) and polarized light microscopic (PLM) indicate the copper(II) complexes to exhibit cold crystal (2) and liquid crystal (4) property. Cyclic voltammograms suggest an irreversible electrochemical process with two one electron charge transfer processes in N,N‐dimethylformamide. Variable temperature magnetic measurements at the solid‐state prove the diamagnetic nature of the low‐spin Ni2+ centres in 1 or 3, as expected from the square‐planar coordination geometry with rather strong ligands. The complexes expose medium level of antioxidant activity in methanol. Optimized geometry and excited state property by DFT/TD‐DFT correspond well to the experimental results of the electronic and molecular structure at the ground state. [ABSTRACT FROM AUTHOR]

A green and efficient ultrasound-mediated protocol was developed for the synthesis of a series of novel Schiff bases derived from quinoline-4-one. The synthetic strategy involved the condensation of 4-oxo-1,4-dihydro-quinoline-3-carboxaldehyde with diverse anilines and heteroaryl amines. The synthesized compounds were characterized using spectroscopic techniques. A comprehensive in vitro cytotoxicity evaluation against HCT116 and HT-29 human colon cancer cell lines revealed that several compounds exhibited potent anticancer activity. Notably, compounds 3c and 3e demonstrated superior cytotoxicity compared to the clinical standard doxorubicin. Mechanistic studies indicated that these lead compounds induced apoptosis, necrosis, and cell cycle arrest at G1 and G2 phases. Furthermore, autophagy induction was observed. In silico ADMET predictions support the potential of compounds 3c and 3e as promising anticancer drug candidates. The molecular docking studies revealed that the Schiff bases 3c and 3e displayed good interaction with VEGFR-2 receptor. These findings underscore the quinoline-4-one scaffold as a valuable template for the development of novel antitumor agents. [ABSTRACT FROM AUTHOR]

This research has progressed to an effective detection chemosensor of zinc, aluminum ions and oxytetracycline hydrochloride antibiotic based on the fluorescence technique. A straightforward method utilizing microwave irradiation was employed to synthesize the salen‐type Schiff base ligand N,N′‐bis(salicylaldehyde)4,5‐dichloro‐1,2‐phenylenediamine (H2I), providing a good 70 % yield. In ethanol, the H2I sensor demonstrated remarkable rapidity, selectivity, and sensitivity in detecting zinc ions. The fluorescence spectrum exhibited a 44‐fold substantial enhancement at 522 nm and achieved a low limit of detection (LOD) of 1.47 μM. Furthermore, the H2I probe's emission intensity increased by 124 times when compared to the ligand's ability to detect Al3+ ions at 494 nm with a LOD value of 7.4 μM. Additional research was done using the H2I probe's effective Zn2+ detection capability. The ability to recognize zinc ions in different real water samples demonstrated a recovery rate of 98.67 % to 103.31 %. Interestingly, a naked‐eye visible fluorescence color of H2I solution impregnated filter papers turned colorless into yell ow under UV irradiation by adding Zn2+ ions, renders it suitable for developing a practical zinc ion detection kit test. In particular, the I‐Zn2+ complex effectively quenched the fluorescence toward oxytetracycline hydrochloride (OTC) with a LOD value of 1.49×10−2 μM in DMSO:H2O (6 : 4, v/v). This is a novel and effective procedure for sensing OTC antibiotic by the I‐Zn2+ complex. These findings hold immense potential for the development of dual fluorescent probes, thereby enhancing sensitivity and specificity in identifying metal ions and antibiotics in a wide range of applications. [ABSTRACT FROM AUTHOR]

This study describes the techniques used for the synthesis and characterization of mononuclear, heterocyclic ligated complexes of Zn(II), Mn(II), and Sn(II). A heterocyclic Schiff base derivative, specifically (E)-2-((benzo[b]thiophen-3-yl)methyleneamino)butanoic acid, has been synthesized by the reaction of benzo[b]thiophene-3-carbaldehyde with 2-aminobutanoic acid. This Schiff base has been reacted with different (M)Cl2 to synthesize the respective metal complexes. For these metal ions, Schiff bases have been proven experimentally to form four-coordinate complexes with 1 : 2 (metal : ligand) ratio. The structural changes of the complexes have been investigated using FT-IR, mass, 1H NMR, 13C NMR spectra, and TGA analysis. The antibacterial efficacy of the Schiff base and its complexes has further been assessed and discussed. Significant amounts of antibacterial and antifungal activity of metal(II) complexes against tetracycline and ketoconazole have been identified. [ABSTRACT FROM AUTHOR]

A ligand has been synthesized from 1-(1-methyl-5-(tosylamino)-1H-1,2,3-triazol-4-yl)ethanone and dimethylpyrimidyl hydrazone, and its copper(II), nickel(II), and zinc(II) complexes have been produced and analyzed. The X-ray diffraction analysis shows that the zinc(II) combination with the N3O donor ligand environment has the form of a tetragonal pyramid. The chelate core of the copper(II) complex is structurally identical, as shown by X-ray data. The coordination core of the nickel(II) complex is an octahedron, which is completed by the solvent molecule. Pharmacological evidence of antibacterial activity was obtained for all the substances. The synthetic compounds have been studied and compared to existing antibiotics like chloramphenicol and amphotericin B for their ability to kill bacteria and fungi, respectively. [ABSTRACT FROM AUTHOR]

Two chiral ferrocenylamine alcohols of (R)-[Fe(η5-C5H5){η5-C5H4CH2NHCH(iPr)(CH2OH)}] (1) and (R)-[Fe(η5-C5H5){η5-C5H4CH2NHCH(C6H5)(CH2OH)}] (2) were synthesized by condensation reaction of ferrocenylformaldehyde and chiral aminoalcohols followed by the reduction with sodium borohydride. The crystal structures of the two compounds were determined by single crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic space group P21212 with a = 16.600(8) Å, b = 28.990(14) Å, c = 6.531(3) Å, and Z = 8. Compound 21.13H2O crystallizes in the monoclinic space group I2 with a = 22.671(4) Å, b = 6.2481(10) Å, c = 22.112(4) Å, β = 96.763(12)°, and Z = 8. [ABSTRACT FROM AUTHOR]

New cyclotriphosphazene derivatives featuring amide–Schiff base linkages with a hydrazine bridge and different terminal ends, such as decyl alkyl chains and hydroxy groups, were successfully synthesized and characterized. Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and CHN elemental analysis were used to characterize the structures of these compounds. The formation of hydrazine-bridged cyclotriphosphazene derivatives with amide–Schiff base linkages was confirmed by the FTIR spectra, showing a primary amine band for the amide linkage around ~3300 cm−1 and a band for the Schiff base linkage near ~1595 cm−1. This was further supported by NMR analysis, which displayed an amide proton (H-N-C=O) at ~δ 10.00 ppm and an azomethine proton (H-C=N) within the δ 8.40–8.70 ppm range. The 31P NMR spectra of cyclotriphosphazene compounds display a singlet at ~δ 8.20 ppm, indicating an upfield shift that suggests the complete substitution of all phosphorus atoms with identical side chains. Furthermore, CHN analysis verified the purity of the synthesized compounds, with a percentage error below 2%. The introduction of hydrazine bridges and amide–Schiff base linkages into the cyclotriphosphazene core significantly enriches the molecular structure with diverse functional groups. These modifications not only improve the compound's stability and reactivity, but also expand its potential for a wide range of applications. [ABSTRACT FROM AUTHOR]

Due to the promising characteristics of aminoguanidine Schiff bases, ongoing research focuses on synthesizing and characterizing different compounds of this class to establish structure–property relationships. However, the pronounced alkalinity of the aminoguanidine residue makes isolating its Schiff bases in neutral form challenging. In the reaction of salicylidene-aminoguanidine ([HL]NO3) with a strong base (NaOH), the partially neutralized product of the formula [HL]NO3∙L·H2O was obtained in the form of single crystals. This compound could be considered a cocrystal in which protonated and neutral forms of the Schiff base coexist. Furthermore, the coordinating properties of [HL]NO3 towards zinc and organotin were investigated, and instead of the expected crystals of complex compounds, a novel polymorph of the ligand was obtained. Additionally, the reaction of [HL]NO3, NH4VO3 and salicylaldehyde was carried out to achieve the condensation of the free NH2-group in the aminoguanidinium fragment, targeting a vanadium(V) complex with tetradentate ligand. However, a purely organic compound containing three salicylaldehyde residues and two imine groups, i.e., C21H18N2O3, was isolated. All the obtained compounds were characterized by elemental and spectroscopic analysis, conductometry and SC-XRD analysis. The data were compared to those of similar structures, and the results provide further insight into the properties of these compounds and their future investigation for potential usage. [ABSTRACT FROM AUTHOR]

A novel Schiff base (BSSMO) and its copper complex have been synthesized, and their structure was delineated using single crystal XRD studies. Computational techniques were used to design and evaluate BSSMO‐based luminophores, revealing a significant intramolecular hydrogen bond within the molecule. Understanding ESIPT is crucial for optimizing photophysical and luminophore properties of organic molecules, especially for advancing optoelectronic devices. The study also explored the mechanisms of GSIPT and ESIPT for these BSSMO‐based luminophores using transition state theory, charge distribution, molecular orbital analysis, and quantum theory of atoms in molecules. Results advocated that BSSMO‐L2 exhibits higher absorption compared with BSSMO‐L1 and the same trend is observed in emission spectral studies. However, the intensity of enol emissions in BSSMO‐L2 is lower than that of keto (BSSMO‐L3) emissions and the S1 (Keto form) emission of BSSMO‐L3 shows significantly larger values, making it attractive for optoelectronic devices. The findings offer valuable insights for the development of ESIPT emitters with distinct photophysical properties. The in silico antidiabetic study of BSSMO‐L2 explores the interaction with PPAR‐γ protein, revealing a moderate affinity and stable complex, enhancing its bio‐potential for future applications. The in vitro anticancer study of Cu‐BSSMO‐L2 complex shows a potential anticancer effect through mitochondrial and extrinsic death receptor mediated pathways. These insights contribute to the design of novel benzenesulfonamide‐based bioactive molecules. [ABSTRACT FROM AUTHOR]

The escalating fascination with Schiff bases stems from their versatile applications in medicine, pharmacology, biology, fine organic synthesis, and industrial processes. This minireview seeks to provide an in‐depth exploration of the synthesis of Schiff bases, specifically focusing on their derivation from 3‐aminopropylalkoxysilanes or 3‐aminopropylsilatranes. Additionally, the review delves into the utilization of Schiff bases in crafting metal complexes, unraveling their practical significance in various domains. Spanning from 1995 to 2024, this review is aimed at encapsulating the evolution of knowledge and advancements in the chemistry of Schiff bases during this period. [ABSTRACT FROM AUTHOR]

Novel selenated azomethine ligand (MSeOH) and its Zn(II), Fe(II), and Cu(II) chelates were synthesized. Their chemical structures were confirmed by molar conductivity, thermal analysis, X‐ray diffraction, IR, NMR, and MS spectroscopic techniques. The antitumor and antimicrobial properties were evaluated against various mammalian cells and pathogenic strains. Furthermore, the antioxidant activities were also assessed using DPPH and SOD bioassays. To gain a deeper understanding of the molecular structure and electronic properties of these complexes, a density functional theory (DFT) study was conducted. The parameters examined in this study provide valuable insight into the bonding, electronic properties, reactivity, and polarity of the compounds under investigation. The biological and theoretical results point to promising activities of the selenated ligand and its complexes. [ABSTRACT FROM AUTHOR]

A novel ternary Ni(II) complexes, [Ni(5Clsal‐phe)(phen)(H2O)] (1) and [Ni(5Clsal‐phe)(bpy)(H2O)]CH3OH (2), (Schiff base derived from the condensation of L‐phenylalanine and 5‐chlorosalicylaldehyde, phen: 1,10‐phenanthroline, bpy: 2,2′‐bipyridine) has been synthesized. The structure of the complexes was clarified by CHN analysis, FTIR, electronic absorption spectroscopy, ESI‐MS, and X‐ray single crystal diffraction methods. In biological activity studies, the interactions of the complexes with calf thymus DNA (CT‐DNA) were examined using fluorescence spectroscopy. The results show that the complexes could bind to CT‐DNA via a minor groove mode. The interactions of the complexes with bovine serum albumin (BSA) were investigated using electronic absorption and fluorescence spectroscopy techniques, and the BSA quenching mechanism was found. The radical scavenging activity of the complexes was investigated in comparison with hederacolchiside, taxifoline, hederasaponin, arachidonoyl dopamine, and silychristin used as standard. Molecular docking simulations were employed to investigate the interactions between the complexes and biomolecules such as DNA and BSA. The results revealed that the complexes insert into DNA via the minor groove and bind to BSA at subdomains I and IIA. These interactions are facilitated by conventional hydrogen bonds, van der Waals forces, alkyl, and π‐alkyl interactions. [ABSTRACT FROM AUTHOR]

A Schiff base, 2-((E)-((furan-2-yl)methylimino)methyl)benzofuran-3-ol has been synthesized and assessed using elemental analysis, infrared spectroscopy, nuclear magnetic resonance, mass spectroscopy and thermal analysis (TGA). The complexes' analytical results confirm the synthesis of a 1:2 [M:L] ratio of the formula [ML2], where M corresponds to the ions Cu(II), Ni(II), Zn(II), Mn(II) and L for the deprotonated Schiff base. Metal ions are bidentately coupled to Schiff base via azomethine-N and phenolic-oxygen groups, as inferred from infrared spectra. The disc diffusion technique has been used to test the ligands and their metal chelates for their antibacterial properties against specified microorganisms. [ABSTRACT FROM AUTHOR]

Isoxazole Schiff bases play an important role in medicinal chemistry, pharmacy, coordination chemistry, and industrial chemistry, therefore, finding easier and more reliable procedures for their synthesis is still in process. The present work deals with a single-step condensation reaction between 3-amino-5-methylisoxazole and various aromatic aldehydes to furnish a Schiff base scaffold of isoxazole (including one new compound) with excellent yields in a short time. The procedure is a solvent-free condition using DMEA as a green catalyst. The products were evaluated for their antibacterial efficacy against gram-positive and gram-negative bacteria including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Salmonella abony. The antioxidant activity of the products was tested and the ascorbic acid and quercetin were used as standards. The produced Schiff bases exhibited the ability to scavenge the free radicals from the DPPH. This means that the products can be used as antioxidants. Two of the synthesized compounds were evaluated for their anticancer activity by testing their cytotoxic potency, which showed diminishing toxicity of cell lines against human breast cancer cell lines and gastric adenocarcinoma cell lines. Therefore, the products can be utilized as anticancer agents. [ABSTRACT FROM AUTHOR]

For the first time, functionalized okra gum with multi-aldehyde groups (OG-CHO) and carboxymethyl chitosan (CMCh) is used to create injectable hydrogels (IHs) via Schiff base reaction at 37 °C. Gelation time is optimized based on the ratio of aldehyde groups of OG-CHO to amine groups of CMCh (9 ± 3 to 2 ± 1 min). Physical characteristics such as gel content (84 ± 2) and porosity (66 ± 3) are assessed. The syringeability, injectability, and self-healing properties are evaluated qualitatively and quantitatively using a rheometer. Structural analysis is carried out by FT-IR and 1H-NMR spectroscopy, while surface morphology and pore size (80 ± 5 µm) are examined via SEM. The swelling ratio is studied in the gel state of the IH in phosphate buffer saline (PBS) at varying pH levels of 5.5, 7.4, and 8.5, revealing a decrease in swelling ratio with increasing pH from 5.5 to 7.4 (75 ± 24 to 635 ± 20%), followed by an increase in swelling at pH 8.5 (724 ± 18.5%). Ciprofloxacin is employed as a model drug for release assays, and drug release behavior in gel forms of IH across different wound pH ranges is evaluated. The swelling and drug release behavior is described using the Korsmeyer–Peppas model, which shows non-Fickian diffusion. Furthermore, biocompatibility (cell viability > 90%), antibacterial assay, and in vitro degradation (~ 98%) are also assessed. [ABSTRACT FROM AUTHOR]

Two isostructural mononuclear cadmium(II) and nickel(II) complexes [Cd(HL)2(NCS)2]∙4CH3OH (1) and [Ni(HL)2(NCS)2]∙4CH3OH (2), where HL is the zwitterionic form of the Schiff base 2,4-difluoro-6-[(2-pyrrolidin-1-ylethylimino)methyl]phenol (HL), were prepared and characterized by elemental analysis, infrared and electronic spectroscopy, as well as X-ray single crystal determination. In both complexes the metal atoms are in octahedral coordination. The Schiff base ligands are coordinate to the metal atoms through phenolate oxygen and imino nitrogen. Molecules of the complexes are stabilized by hydrogen bonds. The biological assay indicates that the complexes have good antimicrobial activities on the bacteria strains Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Different Schiff base complexes were prepared by immobilizing three aldehydes (4-Hydroxybenzaldehyde, 2-hydroxybenzaldehyde, and 2-Pyridinecarboxaldehyde) on graphene oxide and were fully characterized using multiple techniques such as FTIR, XRD, TGA, BET, SEM-EDS, and TEM. Then efficient heterogeneous catalysts were checked out in the selective catalytic oxidation of benzylic alcohols. The effects of different parameters, such as reaction time and temperature, were examined to obtain optimum reaction conditions. The solvent-free oxidation reaction of benzylic alcohols showed a conversion above 70% and selectivity higher than 95% in the presence of cobalt (II) Schiff base catalysts using H2O2 as an oxidant after 40 min of reaction. The reusability experiment results specified that the prepared catalysts could maintain high catalytic activity in the oxidation of benzylic alcohols (>80%) and selectivity (>96%) even after being used for three cycles. [ABSTRACT FROM AUTHOR]

Schiff bases possess a range of unique physical, chemical and medicinal properties, which contribute to their potency as biological agents. A Schiff base was synthesized, which consisted of 4-chloro aniline and vanillin. The successful formation of the compound was confirmed by their comparable FTIR, UV–Vis, 1HNMR and 1 3 CNMR spectra. The compound was analyzed using X-ray crystallography, which revealed that it crystallizes in the monoclinic system with the space group P21/c. The Hirshfeld surface analysis revealed valuable information about the intermolecular interactions present in the crystal lattice. The most common contacts observed were between hydrogen and hydrogen, as well as carbon and hydrogen. The obtained fluorescence values of 375 nm and 412 nm at excitation wavelength 322 nm strongly indicated the luminescent nature of the compound. The thermal stability of the compound was assessed through thermogravimetric analysis (TGA). DFT was used to optimize the geometry using the B3LYP/cc-pVDZ basis set. The compound exhibited an energy gap of 2.35 electron volts (eV). According to the analysis of molecular electrostatic potential, C and O atoms were found to be electrophilic. According to Mulliken charge analysis, C atoms possess both positive and negative charges, hydrogen atoms exclusively carry positive charges, and Cl, O and N atoms exclusively carry negative charges. Upon analysis of the molecule, the electron localization function discovered that the atoms of carbon, nitrogen and chlorine exhibited delocalized electron density. Also, the localized orbital locator identified the localized orbital positions in the hydrogen atoms. The reduced density gradient (RDG) maps exhibit a wide range of noncovalent interactions. In comparison to the standard amoxicillin, the synthesized compound demonstrated moderate antimicrobial efficacy against the gram-positive bacteria Klebsiella pneumoniae and the fungi Candida albicans. The compound's concentration-dependent antioxidant and anti-inflammatory properties were demonstrated through in vitro biological evaluation using 2,2-diphenyl-1-picrylhydrazyl and human red blood cell (HRBC) methods. The compound was docked using the proteins 7BYE and 4LEB were chosen from both organisms. The lowest binding attractions obtained were −3.40 kcal/mol for 7BYE and −4.51 kcal/mol for 4LEB. To investigate the stability of the protein–ligand complex, molecular dynamic simulation was employed. The ligands in silico toxicity potentialities were analyzed using seven toxicity models and the results indicated that the ligand is biocompatible. This study presents a comprehensive analysis of a Schiff's base compound, synthesized from vanillic aldehyde and chloro aniline. The research encompasses detailed crystal structure examination, including Hirschfeld surface analysis, providing insights into the compound's molecular interactions. Additionally, the paper explores the compound's potential biological applications through in vitro antimicrobial, antioxidant, and anti-inflammatory assays, complemented by in silico predictions of its biological properties. [ABSTRACT FROM AUTHOR]

Water contamination by hazardous heavy metal ions and organic compounds causes environmental damage towards aquatic species and human health. Thus the evolution of highly selective, affordable, rapid and effective analytical tools for the removal and detection of toxic heavy metal ions and organic compounds in aqueous environments is a challenging objective. Electrochemical detection of metal ions and organic compounds is a very useful and effective method, where modified electrodes with metal nanocomposite particles are used. Materials with high porosity, low-charge transfer resistance and large electroactive area are desirable for electrode modification in order to act as an efficient electrochemical sensor. It has been established that natural polysaccharide-based graft copolymers with acrylic monomers can be efficiently used as 'bio-template' for preparing mono and bimetallic/metal oxide composite nanoparticles for sensing and catalytic applications. This is because of the fact that polysaccharide-based graft copolymers are eco-friendly in nature and have the potential to act as reducing and stabilizing agents. The bio-template-based metal/metal oxide nanocomposites are successfully used for the electrochemical sensing of some heavy metal ions, like Hg2+, Cd2+, Th4+, Zn2+, Pb2+, etc., and toxic phenolic compounds, and also show efficient catalytic application in azo dye degradation and p-nitrophenol reduction. The developed electrochemical sensors are selective, sensitive and effective for the detection of toxic heavy metal ions in real water samples. Here we summarize the various investigations carried out using metal/metal oxide nanocomposite particles (mono and bimetallic) in electrochemical sensing of toxic heavy metal ions and catalytic applications. [ABSTRACT FROM AUTHOR]

ABSTRACT Bayoud disease, which is caused by the fungus Fusarium oxysporum f. sp. albedinis (FOA), is a severe threat to date palm cultivation in North Africa and the Middle East; thus, effective antifungal treatments are urgently required. In response to this, the present study develops, characterizes, and tests imidazo[1,2‐a]pyrimidine–Schiff base derivatives as potential antifungal compounds. A series of these derivatives (labeled IMP‐1 to IMP‐6) was obtained using a facile conventional synthetic route that holds the potential for scalable production. The structures of the samples were characterized using traditional spectroscopic techniques, while IMP‐1 and IMP‐3 were subjected to single‐crystal X‐ray diffraction analysis to verify the structural assignment of the synthesized compounds. Screening analysis of the antifungal activity of the IMPs against FOA demonstrated remarkable inhibition effects, with IC50 values ranging from 4.7 to 2.6 μg/mL. In particular, IMP‐6 demonstrated exceptional potency, with an inhibition rate exceeding 97% at a low concentration of only 16.42 μM, thus outperforming many previously reported antifungal compounds. Homology modeling and molecular docking analysis were also conducted to understand how these novel antifungal agents interact with their target, with the experimental and theoretical approaches producing consistent results. [ABSTRACT FROM AUTHOR]

ABSTRACT Six new complexes of Co(II), Cu(II), and Zn(II) metal were synthesized by microwave‐assisted green method from fluorinated Schiff base ligands. The Schiff base ligands were prepared by the condensation reaction of 4‐(p‐fluorophenyl)‐5‐methyl‐2‐aminothiazole with 4‐methylsalicyldehyde (L1H) and 4‐methoxysalicyldehyde (L2H). FT‐IR, NMR, and HR‐MS spectral data confirm the tridentate nature of ligands in Co(II) and Zn(II) complexes and the bidentate nature in Cu(II) complexes. The elemental analysis and TGA study revealed 1:2 (M:L) stoichiometry in all synthesized metal complexes. Electronic absorption, magnetic susceptibility, and XRD study express the geometry and crystal systems of complexes. The antimicrobial and anticancer analysis of the synthesized ligands and their complexes were achieved. The results indicate that Co(II) and Cu(II) complexes of L2H have greater potency against Gram‐positive bacteria. In contrast, Co(II) and Cu(II) complexes of L1H exhibited greater zone of inhibition against Gram‐negative and fungal strains. Furthermore, among the synthesized ligands and their complexes, the Zn(II) complex of the L2H ligand was found to exhibit potent anticancer activity with IC50 values of 16.18 and 11.10 μM against MDA‐MB‐231 and A549 cell lines compared to other complexes and parent ligands. Molecular docking study against EGFR (PDB: 5XGM) shows strong binding interactions and good binding free energy to support the experimental results. [ABSTRACT FROM AUTHOR]

ABSTRACT This study explores the potential of newly synthesized macrocyclic Schiff base metal complexes containing Zn(II), Cu(II), Ni(II) and Co(II) ions as Topoisomerase IIβ inhibitors. The complexes were derived from the condensation of 2,3‐diamino‐5‐bromopyridine and 2,5‐thiophenedicarboxaldehyde. Their formation was confirmed through various spectroscopic techniques. To gain insights into their structure and potential biological activity, computational modeling was employed. The density functional theory (DFT) was utilized to optimize the molecular geometries of the complexes. Furthermore, in silico docking simulations with the AutoDock Vina and GOLD scoring function investigated their binding interactions with Topoisomerase IIβ, an enzyme critical for cancer cell proliferation. The combined computational analysis revealed promising binding affinities for all complexes, with complex 3b demonstrating the most favorable interaction with the target enzyme having binding energy −8.56 kcal/mol. To validate these in silico predictions, the cytotoxicity of the complexes was evaluated using the established MTT assay. The observed cytotoxicity results complemented the anticipated binding patterns, with Cu(II) complex 3b demonstrating the strongest inhibitory effect on cancer cells with IC50 value 0.04 μM. Additionally, the hemolytic effect of the complexes on human red blood cells (hRBCs) was assessed to determine their biocompatibility. This strong correlation between predicted interactions, observed cytotoxicity, and minimal hemolytic effect highlights the potential of these complexes, particularly 3b, as promising leads for developing novel anticancer drugs targeting Topoisomerase IIβ. Future research will focus on elucidating the detailed mechanism of action of these complexes and exploring their broader pharmacological profile. [ABSTRACT FROM AUTHOR]

A newly developed dual‐functional fluorescence sensing probe (phenylhydrazinyl pyridine) Schiff base (SB) has been designed with good selectivity for distinguishing Mg2+ and Al3+ metal ions in different solvent solutions. SB exhibits quick and visual turn‐on fluorescence enhancement in response to Mg2+ and Al3+ detection. The addition of Mg2+ in ACN–HEPES buffer (1 : 1, v/v, pH 7.2) at (λmax=390 nm) and Al3+ in MeOH–HEPES buffer (1 : 1, v/v, pH 7.2) at (λmax=360 nm) resulted in significant enhancement of fluorescence, up to 7–9 times. These low detection limits of 7.1×10−6 M (7.1 μM) and 5.15×10−7 M (0.51 μM) for Mg2+ and Al3+, respectively, have been achieved by this solvent‐controlled platform. Due to the sensing potential towards Mg2+, the probe was utilized as an imaging material for breast cancer cells. 1H‐NMR studies were utilized to explore SB's sensing mechanism through turn‐on fluorescence. Density functional theory (DFT) calculations were utilized to validate optimized SB and its intricate geometries, which govern the sensing mechanism in the solvent environment. Such a probe has extensive potential applications in bioimaging and the assessment of the quality of wastewater. [ABSTRACT FROM AUTHOR]

Phenol Schiff bases can conveniently be prepared in high yield by the reaction of the appropriate aminophenols and aldehydes in solventless condition. The final target compounds were characterized by FT‐IR, 1HNMR, 13CNMR, and Mass spectroscopy. Microwave assistance reduced the reaction time and solvent, increased the yield, purity, and eased the work up. The compounds were found to possess moderate to good antibacterial activity implying that the synthesized compounds may make excellent candidates for further studies aimed at discovering novel antibacterial agents. In vitro antioxidant qualities of the synthesized Schiff bases are also evaluated. In the tests for reducing power and radical scavenging, all the compounds demonstrated strong antioxidant activity even surpassing that of the positive control, Trolox. [ABSTRACT FROM AUTHOR]