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Diabetic foot ulcers (DFU) are notoriously challenging to heal due to severe infection, excessive inflammation, and difficulty in angiogenesis. In response to these problems, first, a pH/glucose dual‐responsive hydrogel dressing (HPC) is constructed using dual dynamic crosslinking through Schiff base and phenylboronate ester between m‐aminophenylboronic acid and adipic dihydrazide bifunctionalized hyaluronic acid (AHP) and oxidized chondroitin sulfate (OCS). Then, polydopamine‐reduced graphene oxide compounded glycine‐modified fullerene (GPC) with photothermal/photodynamic synergistic antibacterial properties and the drug pirfenidone (PFD) with pro‐angiogenesis and suppress inflammatory are loaded into the above HPC hydrogel. Based on the response of Schiff base/phenylboronate ester to pH/glucose, the HPC/GPC/PFD (HPCG/PFD) hydrogel can accelerate the release of PFD, thereby improving excessive inflammation and angiogenesis in DFU. In addition, dual dynamic crosslinking provided the hydrogel with good on‐demand removal and self‐healing performance, while GPC brought good tissue adhesion, antioxidation, and electrical conductivity to the hydrogel. The rheology, morphology, mechanical properties, swelling, degradation, and biocompatibility of the hydrogel have been well verified. Finally, in the DFU model of rats, this hydrogel can promote wound repair by reducing infection and inflammation, accelerating wound closure, and enhancing epidermal regeneration, collagen deposition, and angiogenesis, showing promoting effect on diabetic wound healing. [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]

ABSTRACT Metal (Co3+, Ni2+, and Pt2+)–centered and noncentered ferrocene–Schiff bases were prepared. They have been structurally characterized by spectroscopic methods, elemental analysis, conductivity, and magnetic moment. Electron spin resonance was used for the characterization of the Co3+‐centered complex. All synthesized compounds showed antibacterial activity against all tested Gram‐positive and Gram‐negative strains, as well as potent antifungal effect against Candida species. Remarkably, these compounds demonstrated greater efficacy against Gram‐positive bacteria than Gram‐negative. Without an additional oxidant or reductant, the compounds exhibited DNA cleavage capability in the dark. The development of synthesized novel chemical compounds having DNA cleavage and antimicrobial activity plays a profound role in the advancement of medical therapeutics. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI) represents a severe neurological condition often coupled with a drastic secondary inflammatory response, which further exacerbates the damage in most cases. Due to their unique electrical and mechanical compatibilities with the spinal cord, the utilization of conductive hydrogels through injection for SCI repair, particularly in scenarios involving non‐uniform and large gaps, has emerged as a promising approach. Herein, leveraging the acidic microenvironment characteristic of acute SCI sites, an injectable conductive hydrogel with pH‐responsive immunoregulation is engineered for SCI repair. Based on the dynamic Schiff base chemistry and covalent photo‐crosslinking, this composite hydrogel, composed of gelatin methacryloyl, oxidized dextran, and MoS2, exhibits adjustable mechanical and conductive properties, enabling a customized match with the natural spinal cord's attributes. Additionally, the incorporation of Wnt5a and its selective release in acidic conditions prompt the immediate suppression of inflammatory factors and enhances neural differentiation and regeneration. In the 2‐mm hemisection mouse SCI model, the optimized conductive hydrogel can effectively bridge the injury gap, establish nerve connections and signal, mitigate inflammatory response, and promoted recovery of mobility. This novel injectable conductive hydrogel system offers a promising advance in therapeutic materials for SCI repair. [ABSTRACT FROM AUTHOR]

ABSTRACT Herein, we report the synthesis of an (E)‐N‐(pyridine‐3‐ylmethylene)pyridine‐2‐amine Schiff base (ENppa) and its Cu (II) complex (Cu‐ENppa) using 2‐aminopyridine (2APy) and pyridine‐3‐carbaldehyde (P3C). This study aimed to investigate the ADMET profiles, electronic features, antibacterial and anticorrosion activities of the synthesized ligand, and its Cu (II) complex. The compounds were characterized using various techniques, including CHN analysis, FT‐IR, 1H and 13C NMR, MALDI‐TOF MS, ICP‐MS, SEM, TGA/DTA, UV–visible spectroscopy, and powder X‐ray diffraction (PXRD). The Cu (II) ion exhibited tetrahedral geometry in the complex by coordinating with two nitrogen atoms, one from an imine group and the other from a pyridine ring. UV–visible spectroscopy and magnetic moment data also supported this geometry. TGA/DTA revealed three stages of decomposition at 141°C°C–255°C, 255°C°C–367°C, and 549°C°C–659°C, with CuO as the final residue. PXRD analysis identified ENppa and Cu‐ENppa as nanocrystallites, with crystallinities of 82% and 49%, respectively. Both compounds were highly effective in inhibiting mild steel corrosion in acidic media, with inhibition efficiencies of 97% and 98%, respective for Cu‐ENppa and ENppa. They also exhibited favorable ADME profiles, indicating potential as drug candidates for in silico ADME studies. The antibacterial activity results demonstrated promising efficacy, with Cu‐ENppa showing higher activity than ENppa. [ABSTRACT FROM AUTHOR]

In this study, new Schiff base derivatives of α‐naphthalene acetic acid containing alkyl phenyl ether fragment have been effectively synthesized through multistep reaction process, characterized by 1H‐NMR and 13C‐NMR spectroscopy. These derivatives have been tested for their in vitro α‐amylase and α‐glucosidase inhibitory activities. In the series, 8 compounds (2j, 2f, 2e, 2m, 2a, 2b, 2l, and 2c) exhibited promising α‐amylase inhibition with IC50 values from 5.38 ± 0.36 to 14.59 ± 0.64 µg/mL. Similarly, in the case of α‐glucosidase inhibitory activity, 10 derivatives (2e, 2f, 2j, 2m, 2b, 2c, 2i, 2d, 2a, and 2l) exhibited excellent activity having IC50 values from 6.96 ± 0.39 to 16.27 ± 0.31 µg/mL, wheras the remaining derivatives exhibited good‐to‐least antidiabetic potential. The ADME properties were calculated for all Schiff base derivatives using Swiss‐ADME web tool. Furthermore, the docking studies identified the binding modes of the compounds. [ABSTRACT FROM AUTHOR]

Current anticancer therapies suffer from issues such as off‐target side effects and the emergence of drug resistance; therefore, the discovery of alternative therapeutic approaches is vital. These can include the development of drugs with different modes of action, and the exploration of new biomolecular targets. For the former, there has been increasing interest in drugs that are activated by an external stimulus (e. g. light irradiation) to generate cytotoxic chemicals such as reactive oxygen species (ROS). For the latter, significant efforts are being directed to explore non‐canonical DNA and RNA structures (e. g. guanine‐quadruplexes), as alternative biomolecular targets. Herein we report the synthesis of a library of 21 new platinum(II)‐Salphen complexes (square planar platinum(II) complexes coordinated to tetradentate O,N,N,O‐Schiff base ligands), and the investigation, for all complexes, of their photophysical and photochemical properties, their interactions with duplex and quadruplex DNA, and their cytotoxicity against HeLa cancer cells both in the dark and upon light irradiation. Thanks to the intrinsic phosphorescence of the platinum(II) complexes, confocal microscopy was used for six of the complexes to determine their cellular permeability and localisation in two cancer cell lines (HeLa and U2OS). Altogether, these studies have allowed us to identify two lead platinum(II) complexes with high guanine‐quadruplex DNA affinity and selectivity, good cell permeability and nuclear localisation, and high cytotoxicity against HeLa cancer cells upon irradiation with no detected cytotoxicity in the dark. [ABSTRACT FROM AUTHOR]

Six Fe(II) complexes with substituted 6‐((quinoline‐8‐ylimino)methyl)phenolates (R2qsal) were synthesized. X‐ray crystal structure determination for [Fe(R2qsal)2], where R=F (1), Cl (2), Br (3), I (4), CF3/H (5), or CN/H (6), revealed mononuclear complexes that crystallize either solvent‐free in case of 1, 5, and 6 or as CH2Cl2 solvates in the case of 2, 3, and 4. Complexes 1–4, which contain π‐donating substituents, exhibit only high‐spin (HS) state, as shown by crystal structure analysis and magnetic measurements. In contrast, complexes 5 and 6, which contain electron‐withdrawing substituents, exist in the low‐spin (LS) state at lower temperatures but exhibit crossover to the HS state above 300 K. Electronic structure calculations show a good correlation between the relative energies of the LS and HS states and the experimentally observed behavior. [ABSTRACT FROM AUTHOR]

Pyrene‐functionalized silicon hybrid porous polymer (TAPPy‐HPP). The hybrid polymer was successfully prepared via a Schiff base reaction using tetra(4‐aminophenyl)pyrene (TAPPy) and tetra(4‐formylphenyl)silane (TFS) as the building blocks.. This hybrid polymer was characterized using IR, solid‐state 13C and 29Si NMR, and elemental analysis. Its morphology was analyzed by PXRD and SEM. Thermal analysis using Thermal analysis using TGA shows that the synthetic polymer has greater thermal stability than its monomers at a temperature of 5 % weight loss (Td5 %) of 392 °C. Although TAPPy‐HPP has a Brunauer‐Emmet‐Teller surface area of 45.4 m2 g−1, it adsorbed dyes with high efficiency, particularly the anionic dye Congo Red (CR), with an adsorption capacity of up to 358 m2 g−1. Moreover, TAPPy‐HPP showed excellent recycling and regenerative properties. This polymer is a promising candidate for a fluorescent chemical sensor for the absorption of dyes due to its exceptional physiochemical stability and intense luminescence. [ABSTRACT FROM AUTHOR]

One of the primary concerns in the development of new chemical reactions pertains to the choice of solvents, many of which can have harmful ecological impacts. Additionally, a major portion of waste generated in the chemical and pharmaceutical industries comes from the solvents employed. The elimination of solvent usage is highly desirable for creation of environmentally friendly chemical processes as it leads to a substantial reduction in waste production. Accordingly, a novel neat reaction was developed for the synthesis of (β‐amino)nitriles as a prominent moiety through a domino process. It involved the use of silylphenyl triflates, Schiff bases, and acetonitrile (CH3CN) in a 1 : 1 : 1 ratio, among which CH3CN served as a starting material rather than a solvent. This reaction was initiated by caesium fluoride (CsF) to form an aryne through 1,2‐elimination followed by sequential 1,2‐addition, proton transfer, and a second 1,2‐addition. Complete conversion was carried out at 25 °C for 1.0 h to give (β‐amino)nitriles in 76–88 % yields. This solvent‐free reaction minimized waste production and reduced costs associated with extra reagents, solvents, and labour. It possesses a compelling E factor and impressive volume productivity. This reaction sets a new benchmark for solvent‐free aryne domino processes in green chemistry advancements. [ABSTRACT FROM AUTHOR]

Four new Ni16 molecular wheels with the general formula [L4Ni16(RCOO)16(H2O)x(MeOH)12‐x] (where H4L=1,4‐bis((E)‐((2'‐hydroxybenzyl)imino)methyl)‐2,3‐naphthalenediol, and R=H or Me) have been isolated and structurally characterised. Complexes C1−C3 (R=Me) were formed using nickel (II) acetate and presented as polymorphs with the same formulation of charged components. The same wheel‐like architecture was observed in C4 (R=H), which was prepared using nickel (II) formate, demonstrating the potential for further versatility of the system. In contrast to similar four‐fold symmetric Ni(II) wheel clusters, measurements of the static magnetic properties of C1 indicated the presence of dominant antiferromagnetic interactions and an S=0 ground state. [ABSTRACT FROM AUTHOR]

The identification of perilous metal ions and the treatment of diseases induced by microorganisms are critical areas requiring attention. We report herein the design and development of an acetylene‐functionalized Schiff base compound 4, using a low‐cost and straightforward approach. This compound 4 exhibits dual functions in the detection of harmful metal ions, particularly Al(III), as well as in the prevention of disorders caused by bacteria, specifically Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis). It was well characterized through the utilization of diverse spectroscopic techniques, such as NMR (1H and 13C), FT‐IR, and mass spectrometry. Furthermore, the complete structure clarification of the Schiff base compound 4 was revealed through the utilization of X‐ray crystallography. The limit of detection (LOD) for Al(III) is 35.5 × 10−8 M, surpassing the WHO drinking water standard of 26.7 µM, underscoring the high sensitivity of compound 4. The antibacterial activity of compound 4 has also been effectively evaluated on Gram‐positive (S. aureus and B. subtilis) bacteria. Furthermore, compound 4 was docked to S. aureus and B. subtilis proteins, which represents outstanding outcomes with binding energies of −7.31 kcal/mol and −7.87 kcal/mol, respectively. The antibacterial activity of the compound 4 in both in vitro and docking studies suggests that it possesses the potential to serve as an antibacterial agent in the future. [ABSTRACT FROM AUTHOR]

In recent developments, graphene quantum dots (GQDs) have emerged as valuable tools for imaging and biosensing. Various modifications on the GQDs with any desired functionality and attachment of organic molecules and/or nanostructures allow tuning their photophysical properties as well as charge transfer dynamics for bioimaging applications. This study focuses on synthesizing and characterizing of polyethyleneimine‐functionalized nitrogen‐doped GQDs (NC1), Schiff base‐ functionalized nitrogen‐doped GQDs (NC2), and silver nanocomposites of these Schiff base‐functionalized nitrogen‐doped GQDs (NC3). We explore their absorption and emission properties to understand their interactions in the ground state. Furthermore, ultrafast transient absorption spectroscopy measurements reveal that the presence of NC3 shortens the excited state lifetime of NC1 due to charge transfer, resulting in reduced fluorescence intensity. Both experimental and DFT results suggest the potential of NC3 for bioimaging and sensing applications, making them promising candidates for phototheranostic purposes. [ABSTRACT FROM AUTHOR]

This study successfully prepared three environmentally friendly Schiff base network (SNW) polymers, SNW‐1, SNW‐2, and SNW‐3, using melamine and aldehyde compounds as raw materials through a microwave‐assisted synthesis method. The SNW materials were applied to catalyze the copolymerization reaction of SO2 and epoxides. Through detailed analysis of the chemical structure and properties of SNW‐1, SNW‐2, and SNW‐3, their catalytic efficiency was thoroughly investigated. Three thermal degradation kinetic models, Flynn–Wall–Ozawa (FWO), Kissinger, and Coats–Redfern, were employed to calculate the kinetic parameters of the thermal degradation of poly(cyclohexene sulfite) (PCS). Potential thermal degradation mechanisms were speculated. Additionally, the Kissinger model accurately described the thermal degradation kinetics features of PCS. Based on experimental results and kinetic analysis, this paper elucidates the potential mechanism of the copolymerization reaction of SO2 and epoxides. The study indicates that microwave‐assisted synthesis exhibits convenience and high efficiency in preparing efficient catalysts, demonstrating significant potential across various application domains. [ABSTRACT FROM AUTHOR]

One of the central focuses in self‐assembly is precisely controlling the self‐assembly pathway so that the target molecules can be produced exclusively. Trans‐1,2‐cyclohexanediamine contains two amino units that form a 60° angle when projected on a plane. This angle naturally favors the formation of triangular products in most cases when trans‐1,2‐cyclohexanediamine is used as a bisamino building block in the synthesis of macrocycles and tubes. Here, we synthesized a slightly bent tetraformyl precursor bearing a central dibenzothiophene moiety, whose 3,7‐positions are functionalized with two m‐phthalaldehyde units. We observed that combining this tetraformyl building block with trans‐1,2‐cyclohexanediamine yielded a quadrangular tube when the concentrations of the precursors were relatively high. Both experimental measurements and theoretical calculations indicate that the formation of this unlikely occurring quadrangular product was driven by the intramolecular C−H⋅⋅⋅π interactions between the dibenzothiophene building blocks within the tube framework. This driving force, however, was disturbed in the triangular tube, a smaller counterpart whose formation was considered previously much more thermodynamically favored. These results improved our fundamental understanding on how to create those products whose syntheses are considered difficult or impossible, by modulating the intramolecular driving forces. [ABSTRACT FROM AUTHOR]

Isatins are extensively researched compounds with diverse applications, particularly as synthetic precursors in pharmaceutical developments. However, their use as optical probes for enantioselective sensing of chiral amines has not been explored to date. Herein, we present a novel chiroptical assay with an optimized isatin that generates strong, red‐shifted circular dichroism (CD) signals at approximately 380 nm upon ketimine formation with chiral amines. The intensity of the induced CD signal increases linearly with the enantiomeric excess of the analyte and thus allows quantitative chirality analysis. The general usefulness of this approach is demonstrated with a broad range of aliphatic and aromatic chiral amines, and by accurate determination of the enantiomeric composition of 10 samples. [ABSTRACT FROM AUTHOR]

In this study, we introduce a novel indole‐containing pyridine‐based Schiff base, (E)‐2‐({[bis(pyridin‐2‐yl)methylidene]hydrazin‐1‐ylidene}methyl)‐1H‐indole, C20H15N5 (2‐DPHI), and its cadmium(II) complex poly[[2‐({[bis(pyridin‐2‐yl)methylidene]hydrazin‐1‐ylidene}methyl)‐1H‐indole]di‐μ‐chlorido‐cadmium(II)], [CdCl2(C20H15N5)]n (pCd2), as potential anticancer agents. The Schiff base was synthesized by reacting dipyridylmethanone hydrazone with indole‐2‐formaldehyde, while the cadmium complex was prepared by combining CdCl2 and 2‐DPHI in methanol at room temperature. Both compounds were evaluated for their cytotoxicity against three human cancer cell lines (A375, A549 and HeLa) and a normal cell line (HFF‐1). The ligand 2‐DPHI exhibited notable antitumour activity, with an IC50 value of 12.22 µM against A375 and 15.17 µM against A549 after 48 h, while the pCd2 complex showed an even stronger inhibition of A375 cells, with an IC50 value of 4.88 µM, outperforming both 2‐DPHI and CdCl2. Both compounds demonstrated lower toxicity towards normal cells compared to cancer cells. The structures of 2‐DPHI and pCd2 were fully characterized using single‐crystal X‐ray diffraction, elemental analysis, high‐resolution mass spectrometry and FT–IR, 1H NMR, 13C NMR and UV–Vis spectroscopy. [ABSTRACT FROM AUTHOR]

Three dinuclear zinc(II) acetate complexes of the general formula [Zn{Ln}(AcO)]2, namely, di‐μ‐acetato‐κ4O:O′‐bis[({2‐[(pyridin‐2‐ylmethylidene)amino]phenyl}sulfanido‐κ3N,N′,S)zinc(II)], [Zn2(C12H9N2S)2(C2H3O2)2] (n = 1), 4, μ‐acetato‐1:2κ2O:O′‐acetato‐2κO‐[μ‐(2‐{[1‐(pyridin‐2‐yl)ethylidene]amino}phenyl)sulfanido‐1κS:2κ3N,N′,S][(2‐{[1‐(pyridin‐2‐yl)ethylidene]amino}phenyl)sulfanido‐1κ3N,N′,S]dizinc(II), [Zn2(C13H11N2S)2(C2H3O2)2] (n = 2), 5, and μ‐acetato‐1:2κ2O:O′‐acetato‐2κO‐[μ‐(2‐{[phenyl(pyridin‐2‐yl)methylidene]amino}phenyl)sulfanido‐1κS:2κ3N,N′,S][(2‐{[phenyl(pyridin‐2‐yl)methylidene]amino}phenyl)sulfanido‐1κ3N,N′,S]dizinc(II)–bis(2‐aminophenyl) disulfide (2/1), [Zn2(C18H13N2S)2(C2H3O2)2]·0.5C12H12N2S2 (n = 3), 6·0.5(2‐APS)2, were obtained from the reaction of 2‐R‐(pyridin‐2‐yl)benzothiazoline precursors (R = H, 1; R = Me, 2; R = Ph, 3) with zinc acetate dihydrate in a 1:1 ratio. All the complexes crystallized as dinuclear species and complex 6 cocrystallized with one molecule of bis(2‐aminophenyl) disulfide (2‐APS)2. The anionic Schiff base ligands {Ln}− displayed a κ2N,κS‐tridentate coordination mode with the formation of two five‐membered chelate rings. In 4, 5 and 6·0.5(2‐APS)2, both ZnII ions are pentacoordinated and the coordination sphere of 4 was different with respect to those in 5 and 6·0.5(2‐APS)2. For 4, the X‐ray diffraction study showed a dinuclear complex containing two bridging acetate ligands linked to both ZnII ions. For 5 and 6·0.5(2‐APS)2, the dinuclear complexes displayed one bridging acetate ligand linked to both ZnII ions, where the first ZnII ion includes a dative bond with one S atom from an adjacent anionic Schiff base {Ln}−, while the second ZnII ion is coordinated to one terminal acetate ligand. In each dinuclear complex, the geometry is the same for both ZnII metal centres. The local geometry of the ZnII cation in 4 is halfway between trigonal bipyramidal and square pyramidal local geometries; in 5 and 6, the local geometries are described as distorted square pyramidal. Hirshfeld surface analysis of 5 and 6 showed the predominance of H...H interactions, as well as the contribution of C—H...C, C—H...O and C—H...S noncovalent interactions to the cohesion of the crystalline network of the ZnII complexes. [ABSTRACT FROM AUTHOR]

The current investigation involved the synthesis and detailed characterization of novel mixed‐ligand complexes of Mn(II) (MnDPPNPH) and Cu(II) (CuDPPNPH). These complexes incorporate 2,6‐di(1H‐pyrazol‐1‐yl)pyridine (DPP) and a Schiff base derived from 2‐hydroxy naphthaldehyde (NPH). The synthesized complexes revealed a stoichiometric ratio of 1:1:1 (metal:DPP:NPH), indicative of an octahedral coordination geometry around the Mn(II) and Cu(II) centers, as represented by the chemical formula [M (DPP)(NPH)(Cl)]. To elucidate their structural and electronic properties, theoretical calculations were performed. These calculations facilitated the optimization of the geometrical structures and provided insights into the molecular orbital characteristics of the complexes. The MnDPPNPH and CuDPPNPH complexes demonstrated potential phenoxazinone synthase mimicking activity by catalyzing aerial coupling of o‐aminophenol (OAPh) to form phenoxazine‐2‐one (phenox). The mimicking activity of these complexes was quantitatively assessed using Michaelis–Menten enzymatic kinetics. Various enzyme kinetics plots were employed to determine several kinetic parameters, including the specificity constant and turnover number (kcat), which are crucial for understanding the efficiency of the catalytic cycles. Remarkably, the synthesized MnDPPNPH and CuDPPNPH complexes exhibited significantly higher turnover numbers (kcat) compared to previously reported complexes. This finding suggests that these new complexes possess superior catalytic activity, highlighting their potential as effective catalysts for reactions mimicking the function of phenoxazinone synthase. [ABSTRACT FROM AUTHOR]

Novel compounds with pharmacological activity were synthesized from Pd(II), Fe(III), Cr(III), Ni(II), and Cu(II) ions with 1‐cyclopropyl‐6‐fluoro‐4‐(2‐hydroxy‐phenylimino)‐7‐piperazin‐1‐yl‐1,4‐dihydro‐quinoline‐3‐carboxylic acid (CFAP). The ligand's NH and OH groups allowed it to interact with the metals as a neutral tridentate. The investigated novel compounds were described using 1H and 13C NMR spectra, FT‐IR spectrums, TGA and UV–Vis (conductance of molecules), and CHN‐analysis. Additionally, the pH profile of the CFAP complexes indicated great stability, and the complexes' stability constant was discovered in the solution. To extract important properties for CFAP and its complexes, computational research was used, CFAPCu, CFAPCr, CFAPNi, and CFAPFe have octahedral geometry, while CFAPPd has square planar geometry. To investigate the molecular geometry, density functional theory calculations (DFT) were carried out. The molar ratio and continuous fluctuation data confirmed that the (M:L) ratio was (1:1). In vitro tests were conducted to evaluate Schiff base's antimicrobial action ligand and its metal chelates against fungal and bacterial infections. The findings showed that the antimicrobial efficacy is as follows: When CFAPPd is compared to fluconazol and ofloxacin as reference medications, it is the highly inhibitor complex. The novel CFAP ligand and its complexes were investigated for In vitro carcinogenic potential against Hep‐G2, MCF‐7, and HCT‐116 cell lines. As compared to the medication vinblastine, the results once again demonstrated that CFAPPd is the most active agent. Moreover, the complexes demnstrated strong reactivity in capturing free radicals when their antioxidant activity was investigated. Viscosity, spectral investigations, and gel electrophoreses were used to identify the interaction between metal chelates and DNA. Every examined compound is shown to be an enthusiastic DNA binder by viscosity and spectrophotometric titration investigations. The heightened hydrophobic and electrostatic interactions between aromatic rings could be the cause of this. Ultimately, these compounds could be regarded as promising bioactive substances. [ABSTRACT FROM AUTHOR]

Salamo‐type ligand H2L was designed and synthesized and reacted with Cu (II) and Zn (II) acetate, respectively, to obtain two binuclear Cu (II) and Zn (II) complexes: [Cu2(L)2]·2CH3OH (1) and [Zn2(L)2] (2) having the same coordination number but distinct geometries. Complex 1 is a Cu (II) complex containing two crystalline ethanol molecules, where two Cu (II) atoms are surrounded by two utterly deprotonated (L)2− parts, forming slightly twisted tetragonal pyramidal configurations of pentacoordinate. In complex 2, two utterly deprotonated (L)2− parts surround two Zn (II) atoms, forming pentadentate twisted triangular bipyramidal configurations. The complexes were elucidated via IR analyses and ultraviolet spectroscopy. Using DFT theoretical calculation, MEPs, IRI, and Hirshfeld surface analysis to investigate further the molecular interactions and reaction sites. Ultimately, the fluorescence characteristics of H2L and its complexes 1 and 2 were discussed. [ABSTRACT FROM AUTHOR]

This study investigates organotin (IV) complexes derived from the recently synthesized quinazoline Schiff base ligand (L). The research involves synthesizing and characterizing these complexes, including elemental analysis, UV–visible, FT‐IR, mass spectra, and conductometric measurements. Advanced studies such as density functional theory (DFT) are employed to gain insights into the stable electronic configuration. Specifically, the study explores the proposed geometry, revealing a distorted octahedral structure for the complexes. The findings contribute as critical molecular characteristics of these newly synthesized complexes, paving the way for potential applications in diverse fields, including medicinal chemistry. Through an investigation into the antimicrobial properties, the efficacy of the synthesized compounds was assessed against a diverse range of bacterial and fungal strains. Remarkably, the complexes demonstrated significant antimicrobial activities, showing potential applications in combating various microbial infections. In an extended exploration of their medical utility, the compounds were examined for their antibiotic properties against Helicobacter pylori. The Schiff base and its metal complexes emerged as promising antibiotics with notable efficacy against H. pylori, suggesting their potential in addressing infections associated with this bacterium. Furthermore, the antitumor potential of the synthesized complexes was investigated, focusing on their impact on MCF‐7 (Breast carcinoma) cells. The organotin (IV) Schiff base complexes in this research showed remarkable efficacy, evidenced by their notably low IC50 values (9, 10, 11 μg/mL) in comparison with cisplatin. In addition to their potent antitumor effects, these complexes exhibited reduced cytotoxicity toward normal cells (VERO cells) compared with cisplatin. The investigation extends to molecular docking, where this approach aims to elucidate their interactions with specific protein structures, including (2JFZ, 1SC7, and 6W41). The primary objective is to clarify the potential properties of these compounds, focusing on their antibiotic efficacy, anti‐H. pylori activity, antitumor potential, and anti‐COVID‐19 properties. [ABSTRACT FROM AUTHOR]

Three new Zn(II) Schiff base complexes, [ZnLCl2] (1), [ZnLBr2] (2) and [ZnL(SCN)2] (3), have been synthesized by adding Zn(II) salts of chloride and bromide to a compartmental ligand with NNO donor prepared through the simple condensation of pyridine‐2‐carboxaldehyde and a substituted aniline. The complexes have been identified using standard physicochemical methods, and their solid‐state structures have been determined through single‐crystal X‐ray analysis. The phosphatase‐like activity of all three complexes has been investigated using 4‐NPP as the model substrate in a DMSO/water medium. Complex 1 exhibits the highest level of phosphatase activity. The reactivity trend shows that complex 1 > complex 2 > complex 3. A plausible mechanism and the causes underlying the activity trend have been explored through DFT study, ESI‐mass spectra and 31P experiments. Complex 1 shows promising potential for use in gene‐targeted therapeutics due to its remarkable performance in DNA digestion. The excellent DNA cleavage result of complex 1 has led to the investigation of its molecular docking interaction with the liver cancer 2 receptor to study its anti‐liver cancer activity. Furthermore, in vitro anticancer activity of complex 1 also shows excellent antiproliferative activity against hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) is a biodegradable aliphatic polyester of significant interest. Owing to its traits, PLA stands out as one of the most widely used polymers in various fields. Nevertheless, environmental conditions, such as heat, UV light, and humidity have negative impacts on the polymer's performance as a result of the accelerating aging process. In this study, we present a novel acceptor–donor (AD) Schiff base molecule that demonstrates significant UV stabilization when incorporated into the polymer's matrix. The stabilization effect of the AD molecule was studied by using the weight loss method and tracking the functional group indices of CO (ICO) and OH (IOH) that emerge because of polymer degradation after irradiation with UV light for 300 h. The films' structures were studied by scanning electronic microscopy (SEM), atomic force microscope (AFM), and energy‐dispersive x‐ray spectroscopy (EDX) to evaluate the stabilization enhancement of AD moiety. The results exhibit a significant decrease in weight loss for blended PLA, in contrast to blank PLA. The weight loss percentage reduced from 2.5 for blank PLA to less than 0.7 for blended PLA. Furthermore, ICO and IOH indices witness a remarkable reduction which verifies the improved photodegradation resulting from AD moiety. The suggested method involves the efficient absorption of UV radiation produced during photo‐degradation by the AD molecule, which then emits this light as visible blue light without causing any damage to PLA film's chemical structure. Our results demonstrate the adaptability of AD molecules as PLA photo‐stabilizers and point to their wider significance for sustainable material applications. This work advances the stability of PLA films and provides opportunities for the creation of novel stabilization techniques based on organic electrical principles. Future studies may examine the multipurpose uses of the AD molecule in sensor materials and other contexts. Highlights: Presenting a novel acceptor–donor Schiff base as a phot stabilizer of PLA.Using the weight loss method and tracking the functional group indices to test the degradation.A significant decrease in weight loss for blended PLA, in contrast to blank PLA.The Schiff base absorbing UV light, excited electrons from ground state to excited state.They return to the ground state and produce bright blue light.These movement of electrons cause no damage to the PLA polymer chains. [ABSTRACT FROM AUTHOR]

Background: This study reports the preparation of 2‐hydroxy‐3‐(4‐(((2‐((2‐(((E)‐4‐(2‐hydroxy‐3‐(trimethylammonio)propoxy)‐3‐methoxybenzylidene)amino)ethyl)amino)ethyl)imino)methyl)‐2‐methoxyphenoxy)‐N,N,N‐trimethylpropan‐1‐aminium (HYM/QA). The adsorbent was employed to extract and concentrate vanadium from its solutions and boiler ash samples. Results: The impact of initial dosage, pH, reaction time and temperature on the sorption behavior of V(V) was examined. Under optimal conditions (pH 5, 0.08 g dose, 45 min at room temperature), a sorption capacity of 392.25 mg g−1 was achieved. The uptake of V(V) on HYM/QA was effectively reversed using 1 mol L−1 NaOH, regenerating the material. After six cycles of sorption and elution, the sorption capability remained at 91.4% of its initial value. The efficiency and selectivity of HYM/QA toward V5+ ions were assessed using the separation factor parameter, revealing limited interference from heavy metals such as Mn2+, Cr3+, Pb2+, Si4+, Al3+, NO32−, HCO3− and Zn2+. The uptake process of HYM/QA for V(V) conformed to the Langmuir and Dubinin–Radushkevich isotherm models and the pseudo‐second‐order kinetic model. HYM/QA was characterized by infrared, Brunauer–Emmett–Teller surface area, 1H NMR, 13C NMR and gas chromatography–mass spectrometry analyses, confirming successful preparation. Thermodynamic assessments suggested that the sorption process is endothermic, spontaneous and becoming more favorable with rising temperature. Conclusion: The optimized conditions were used to adsorb vanadium from boiler ash samples, and the obtained vanadium pentaoxide was analyzed and confirmed using various tools, demonstrating the material's effectiveness for vanadium extraction. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

ABSTRACT The current study involved production, comprehensive structural analysis, and physicochemical characterizing of two distinctive complexes namely, Cu(TBH) and Zn(TBH); TBH donor ligand: N′‐(1‐(3,6‐dihydro‐4‐hydroxy‐2,6‐dioxo‐2H‐1,3‐thiazin‐5‐yl)ethylidene)‐2‐hydroxybenzohydrazide) using a wide range of analytical methods, including elemental analysis, UV–Vis, FT‐IR, and 1HNMR spectrometry, molar conductivity and magnetic susceptibility measurements, and thermal analysis. According to the findings, chelation can occur through O, N, and O donor atoms of monoanionic chelator for generating mono‐nuclear chelates with tetrahedral geometry for Cu (II) and octahedral geometry for Zn (II). The anticarcinogenic ability of TBH chelator and its coordinated compounds against human liver cancer (HepG‐2) was investigated. The Cu(TBH) complex was found to have selective and promising anticancer activity against a liver cancer cell line, with lower IC50 (liver carcinoma cell line) and higher IC50 (normal human cell line) values than other produced compounds and standard drugs. Utilizing DFT computations, the molecular structures of the TBH and its complexes were verified, offering a detailed understanding of their quantum chemical characteristics. A quantitative structure–activity relationship (QSAR) model, which illustrates the association between DFT‐computed descriptors and biological activities pIC50, was also created using multiple linear regression (MLR) on the synthesized compounds as anticancer medicines. Additionally, there are no issues with the produced compounds' oral bioavailability according to (ROF) Lipinski's rule of five. Furthermore, docking studies of the synthesized TBH chelator and its chelates with CDK2 kinase have been performed to validate the biological findings. According to our findings, the novel Cu(TBH) nanodrug exhibits considerable cytotoxic activity, prompting further study into its pharmacological profile and exploring its potential in drug development. [ABSTRACT FROM AUTHOR]

ABSTRACT This article explains the synthesis of three Schiff base Cu(II) complexes derived from 3‐hydroxybenzaldehyde and ethylenediamine using three distinct copper anionic salts, and it explores the effects of those salts on the properties of the complexes. Elemental analysis, electronic spectra, FT‐IR, ESR, molar conductance, magnetic measurement, thermogravimetric analysis and PXRD were used to characterize the compounds. The anionic salt has been demonstrated to exhibit distinctive characteristics on Gram‐positive and Gram‐negative bacteria in terms of structure, DNA binding, cell viability, DNA breakage and activity. Furthermore, this ligand L1 and its derivatives indicated positive antifungal efficacy against Aspergillus niger and Trichophyton tonsurans. The study elucidates the manner in which distinct anion salts impacted the properties of complexes and their antifungal, anticancer and antibacterial outcomes. [ABSTRACT FROM AUTHOR]

ABSTRACT This research focused on the design and comprehensive characterization of two novel transition metal complexes derived from the symmetrical Schiff base 2‐[(2‐chloroquinolin‐3‐yl)methylidene]aminobenzenethiol (CQAT), coordinated with nickel(II) (NiCQAT) and copper(II) (CuCQAT) ions. The structural elucidation of these complexes was achieved through a range of advanced analytical techniques. Thermal analysis revealed the stability and decomposition patterns of the complexes, supporting the identification of their coordination geometries. The collective data indicated that both NiCQAT and CuCQAT complexes adopt octahedral coordination, with the specific formulas [Ni(CQAT)2(H2O)2] and [Cu(CQAT)2(H2O)2], respectively. To complement the experimental findings, density functional theory (DFT) calculations were employed. These theoretical calculations confirmed the proposed molecular structures and provided detailed insights into key quantum chemical parameters, such as HOMO–LUMO energies, molecular orbitals, and electronic distributions, which are crucial for understanding the complexes' reactivity and stability. Furthermore, extensive in vitro biological evaluations were conducted to assess the anti‐inflammatory and antioxidant properties of the synthesized complexes. These assays demonstrated that both NiCQAT and CuCQAT exhibited significantly enhanced bioactivity compared to the free CQAT ligand, suggesting a synergistic effect of metal coordination on the ligand's biological efficacy. To further explore the mode of action, molecular docking studies were performed targeting two key proteins—human cyclooxygenase‐2 (PDB ID: 5IKT) and human peroxiredoxin 2 (PDB ID: 5IJT). The docking simulations provided valuable insights into the binding affinities, interaction energies, and key amino acid residues involved in the binding process, offering a molecular‐level understanding of their potential biological mechanisms. The findings from these multidisciplinary studies highlight the therapeutic potential of CQAT and its nickel and copper complexes, positioning them as promising candidates for further development in the field of medicinal chemistry. [ABSTRACT FROM AUTHOR]

Biopotent hybrid diorganotin(IV) complexes, derived from salicylaldehyde Schiff bases having general formula R2SnL, where LH = (OH)C6H4HC: NCR′(R″)CHR‴OH] [where R = Me or Bu], were logically designed, generated, and characterized using spectroscopic techniques, single‐crystal X‐ray investigations, and DFT studies. Different diorganotin(IV) complexes were synthesized because of interaction between diorganotin(IV) dichloride and sodium salts of Schiff bases of salicylaldehyde ligand in anhydrous refluxing THF at 1:1 and 1:2 molar ratio (Product A and B). The chelating property of Schiff bases replaces organo group from diorganotin(IV) dichloride. It creates an O2SnL type of complex when diorganotin(IV) dichloride and ligand interact in 1:2 ratio, which is this study's most fascinating aspect. The characterization of these complexes is aided by physicochemical and spectroscopic investigations, including IR and NMR (1H, 13C, and 119Sn). Single‐crystal X‐ray investigations, mass spectrum studies, and DFT investigations suggest the dimeric structure of these compounds. These diorganotin(IV) complexes have a dimeric structure containing hexacoordinated central tin atom. Two µ2─O atoms bridge the gap between two Sn(IV) atoms in the dimeric dimethyltin(IV) complexes. The DPPH assay results for radical scavenging activity and IC50 values demonstrate the antioxidative potential of diorganotin(IV). [ABSTRACT FROM AUTHOR]

The utilization of biologically active metal complexes in medicine is gaining recognition as an alternative approach to traditional biologically active organic molecules, which often exhibit undesirable side effects. This study focuses on the synthesis and characterization of a Co(II) complex derived from the (E)‐2‐((2‐hydroxybenzylidene)amino)‐5‐methylbenzonitrile ligand system (HL) and cobalt(II) acetate tetrahydrate in a dichloromethane/methanol solution. A comprehensive characterization strategy was employed, involving proton and carbon nuclear magnetic resonance, infrared, electronic spectra, PXRD, SEM‐EDX, and mass spectroscopies, as well as elemental analysis (CHN and Co), TGA, and molar conductance, to confirm the chemical structures of the ligand and its complex. The infrared spectral data revealed the ligand as a bidentate ligand, chelating the Co(II) ion through the oxygen and nitrogen atoms of the phenolate and imine groups. Additionally, PXRD and SEM analyses indicated crystalline and amorphous properties for the ligand and complex, respectively. Assessment of antimicrobial potential using a modified disc diffusion method, with streptomycin as the positive control, demonstrated the complex's enhanced antibacterial activity compared to the ligand against all tested bacteria, showing a concentration‐dependent response. Similarly, antioxidant studies revealed promising results, with the complex exhibiting superior DPPH radical scavenging activity (IC50 values: ligand 64.5 μg.mL−1, complex 43.1 μg.mL−1). Theoretical analysis through DFT calculations and molecular docking provided insights into the electronic properties and binding affinity of the ligand and complex, supporting the experimental findings and affirming the biological activities exhibited by the compounds. Overall, this research showcases the synthesis, characterization, and biological evaluation of a promising Co(II) complex, highlighting its potential as an effective antimicrobial and antioxidant agent. [ABSTRACT FROM AUTHOR]

Efficient and selective fluorescence sensors based on katiragum dialdehyde‐ amino acid Schiff's base is developed for fluorometric sensing to detect vanillin, Cu2+ ions and 4‐nitrophenol (4NP) in their aqueous solution. Two Schiff bases namely katiragum dialdehyde‐ arginine (KGDR) and katiragum dialdehyde‐ tryptophan (KGDT) are developed in the author's laboratory between which KGDR can detect vanillin with a detection limit of 60.29 nM whereas KGDT can detect both Cu2+ ion and 4NP with a detection limit of 72.6 nM and 97.83 nM respectively. KGDR and KGDT show significant quantum yields of 0.47 % and 0.25 % compared to a standard known substance fluorescein (0.97 %). The detection limit of vanillin, Cu2+ ions and 4NP are lower than other reported sensors. The developed Schiff base KGDR and KGDT show excellent recovery percentage and relative standard deviation (RSD) values in real sample analysis. [ABSTRACT FROM AUTHOR]

Compound 4, a Schiff base‐containing pyrimidine moiety, was synthesized from the reaction of N‐amino pyrimidine derivative with 4‐fluorobenzaldehyde. The molecular and crystallographic structure of 4 was determined by the SC‐XRD method. According to these results, compound 4 crystallized in the triclinic P‐1 space group, and the stability of its crystal structure was ensured through intermolecular C−H⋅⋅⋅π and π⋅⋅⋅π interactions. In addition to the antibacterial effects of the molecule on some Gram‐positive and Gram‐negative bacteria, the inhibition of biofilm formation in P. aeruginosa PAO1 and the production of violacein pigment in Chromobacterium violaceum (C. violaceum) 12472 were studied. The results demonstrated that compound 4 had strong effectiveness in preventing the formation of biofilms produced by PAO1 with an inhibition rate of 69 %. Extensive theoretical calculation studies of molecule have been conducted and the molecular structure of 4 has been optimized in the ground state using density functional theory (DFT). The investigated compound's frontier molecular orbitals, chemical parameters, and molecular electrostatic potential surfaces were examined. Molecular docking studies were performed to explain the binding interaction 4 with the high inhibitory effect against C. violaceum phenylalanine hydroxylase D139A (PDB ID: 4Q3Y), D139E (PDB ID: 4Q3W), D139K (PDB ID: 4Q3Z), and D139N (PDB ID: 4Q3X) mutations. [ABSTRACT FROM AUTHOR]

This work focuses on the rapid synthesis of Schiff bases with green protocols, where P2CA (Pyridine‐2‐carboxylic acid) is utilized as a catalyst. The condensation reaction of aldehydes and anilines, facilitated by P2CA, resulted in the production of Schiff bases in good to excellent yield within a remarkably short time of up to 15 min. The electronic effect of the various substituents on aldehyde and aniline, in combination with the catalytic effect of P2CA, accelerated the reactions under mild conditions. The reusability of the catalyst was thoroughly examined, and the catalyst was characterized over every cycle. Importantly, this approach is not only green and sustainable, but also cost‐effective, harmless, and environmentally friendly, thanks to the affordability and benign nature of P2CA. [ABSTRACT FROM AUTHOR]

Ambroxol hydrochloride is a pharmaceutical compound that is primarily used to treat respiratory disorders characterized by excessive mucus production. It is a mucolytic agent used in treating various respiratory conditions, including bronchitis, asthma, COPD (Chronic Obstructive Pulmonary Disease), and cystic fibrosis. The standard industrial‐scale synthesis involves Schiff's base formation followed by reduction; this method is widely adopted due to its efficiency and cost‐effectiveness. Apart from this, various patented methodologies have emerged recently, along with novel therapeutic applications, where it is used for treating Parkinson's and Alzheimer's diseases, including anti‐inflammatory and antioxidant properties. These findings open new avenues for its use in various medical treatments. The current review aims to assess the industrial scale processes in the current market, examine its pharmacological action, and explore recently evaluated therapeutic applications, offering a comprehensive overview of its potential in modern medicine. [ABSTRACT FROM AUTHOR]

Polysaccharide‐based hydrogels are promising for biomedical applications such as drug delivery owing to their biocompatibility, biodegradability, and bioactivities. In particular, there is a need for hydrogels with injectability for minimally invasive therapies and controlled sustained release for sustained drug effect. Hydrogels made from carboxymethyl chitosan (CMC) and tannic acid (TA) (CMC‐TA) contain dynamic covalent bonds owing to autoxidation between CMC and TA, and interact with proteins via TA, elucidation of the detailed mechanism of dynamic covalent bonding in CMC‐TA hydrogels will facilitate stable loading and zero‐order release of proteins. Herein, the physical properties of oxidized CMC‐TA (Oxi‐CMC‐TA) prepared for the encapsulation and sustained release of proteins are explored. Following incubation at 37 °C for 24 h, CMC‐TA undergoes secondary crosslinking by autoxidation to produce Oxi‐CMC‐TA. Notably, CMC‐TA is viscoelastic and shear‐thinning, allowing for injection and 3D bioprinting. Indeed, CMC‐TA can be 3D‐printed with green fluorescent protein (GFP) encapsulated in its matrix. Oxi‐CMC‐TA also exhibits an affinity for protein owing to its gallol groups, enabling Oxi‐CMC‐TA to collect GFP in aqueous solutions against a concentration gradient. Moreover, Oxi‐CMC‐TA releases GFP over 15 days. Injectable, 3D‐printable, protein‐collecting, and zero‐order sustained‐releasing Oxi‐CMC‐TA has the potential to make a significant contribution to drug delivery. [ABSTRACT FROM AUTHOR]

ABSTRACT The novel Schiff base, (Z)‐2‐(1‐((3‐methylpyridin‐2‐yl)imino)ethyl)phenol (HL), was synthesized by reacting 1‐(2‐hydroxyphenyl)ethanone with 3‐methylpyridin‐2‐amine. Metal complexes [M (L)n (H2O)2] (M = Co and Cu, n = 2) were synthesized and characterized utilizing various analytical techniques including UV–visible spectroscopy, FTIR, elemental analysis, molar conductance, 1H NMR, thermal analysis, and magnetic moment measurement. The findings indicated that the Co+2 and Cu+2 complexes exhibited octahedral geometries. In vitro biological activity testing was conducted to evaluate the antimicrobial potential of the complexes against Bacillus subtilis (B. subtilis) and Escherichia coli (E. coli) bacteria strains. Similarly, molecular docking was conducted to elucidate the interactions between the active sites of protein–metal complexes and dihydrofolate reductase as well as ferrochelatase. [ABSTRACT FROM AUTHOR]

Despite the continued dominance of detrimental formaldehyde‐based binders in the wood reconstituted products, there is a growing push to develop more environmentally friendly alternatives. Cellulose‐based biomass adhesives have been extensively researched and documented. However, their industrial application is limited due to inadequate water resistance and suboptimal coating ability. In this study, a cellulose‐derived wood binder with a hyperbranched entangling structure was synthesized by covalently cross‐linking branched polyethylenimine and oxycellulose through Schiff base formation. The dry/wet bonding strength of the prepared plywood was 2.07 and 1.52 MPa, respectively, exhibiting a remarkable increase and breakthrough compared to that of pure oxidized cellulose binder. This can be attributed to the formation of a water‐resistant Schiff base tangle network, which enhances the toughness of the adhesive. Notably, the pure cellulose adhesive tends to agglomerate on the wood surface, whereas the hyperbranched modified cellulose adhesive exhibits a more uniform coating ability. This study further demonstrates the reliable potential of tangle structures based on Schiff base reactions in the development of biomass‐based adhesives. Highlights: A high bonding strength cellulose‐based wood adhesive was prepared.The Schiff base reactions have been used to construct cross‐linked structures.The cross‐linked network structure provides excellent water resistance.The cured cellulose‐based adhesive has excellent dry/wet bonding strength. [ABSTRACT FROM AUTHOR]

The anthracene‐appended Schiff base N1‐(anthracene‐9‐methylene)benzene‐1,2‐diamine and its Cu(II) complex has been synthesized and anchored on MCM‐41 support (MCM@CP@AnL@Cu 1). The synthesized catalyst was characterized by various analytical techniques including single crystal X‐ray. Malononitrile, 1,3‐dione, and aromatic aldehydes with various substituents were used in one‐pot, three‐component synthesis of 2‐amino‐3‐cyano‐4H‐pyran/chromene derivatives using above catalyst 1. All the products of the catalytic reaction were characterized by 1H and 13C NMR spectra. We have also proposed a probable reaction mechanism involved in the catalytic reaction. The present catalyst has several advantages like works in mild reaction conditions, that is, at 80 °C, gives higher yields up to 97%, has thermal stability up to 295 °C, and can be reused up to 5 cycles. The immobilized material did not show any considerable leaching or deterioration throughout the catalytic reactions, confirming that it possesses a practical benefit over homogeneous catalysis. The MCM@CP@AnL@Cu (1) is believed to be a good solid heterogeneous catalyst and meets the need of green chemistry for sustainable environment. To the best of our knowledge, this is first example of anthracene‐based Cu (II)‐Schiff base complexes immobilized on modified MCM‐41 surfaces for the multicomponent synthesis of 4H‐pyrans. [ABSTRACT FROM AUTHOR]

Levodopa, a widely prescribed drug in Parkinson's disease treatment, stands as the foremost prodrug of dopamine. An affordable self‐testing kit is utilized to monitor levodopa content in anti‐parkinson drugs in human serum. A photoluminescent trinuclear Zn(II) complex [Zn3(L)2(κ1‐OAc)2(κ2‐OAc)2] has been synthesized, which cleaves into mononuclear ZC in aqueous solution. ZC was found to detect L‐Dopa in Tris‐HCl buffer, exhibiting a moderate decrease in PL‐emission. The real‐life utility of the ZC probe is limited, for its lower sensitivity (LOD 35.3 μM) and separation challenges. Therefore, an interface between homogeneous and heterogeneous supports has been explored, leading to the strategic development of NGOZC, where ZC was grafted onto NGOQD (Graphene oxide quantum dots). This material enables naked‐ eye detection under both ambient and UV light with color change from bright cyan to green, followed by dark. The nitrogen doping effect was investigated by several comparative investigations involving the synthesis of ZC‐grafted GOQD, leading to enhanced quenching performance. Steady‐state and time‐resolved fluorescence titration study, morphological analysis, and computational calculations have been performed to get insights into the sensing mechanism. To the best of our knowledge, this as‐synthesized NGOZC (LOD 1.78 nM) represents a promising strategy and platform for applications in biosensors, especially for Parkinson's and Alzheimer's diseases. [ABSTRACT FROM AUTHOR]

This study investigates the creation of multifunctional scaffolds based on alginate dialdehyde (ADA) and gelatin (GEL) incorporating ferulic acid (FA), a phytotherapeutic agent with diverse pharmacological properties, and human platelet lysate (HPL). The multimaterial hydrogels were characterized in terms of degradation/swelling behavior showing that HPL decelerates the degradation process of ADA‐GEL hydrogels in absence of FA. A FA release study confirmed that the presence of HPL does not affect the FA release ability of ADA‐GEL hydrogel. A trinitrobenzenesulfonic acid (TNBS) assay confirmed no influence of HPL on the Schiff's base formation. The addition of HPL was shown to lead to a decrease in stiffness, mechanical stability, and viscosity of ADA‐GEL‐HPL inks. This effect was also observed for ADA‐GEL‐HPL inks when investigating their three‐dimensional (3D) printing ability. Cytocompatibility tests and a 3D bioprinting study confirmed the beneficial impact of the addition of HPL on MC3T3‐E1 cells. Moreover, an antibacterial effect provided by the addition of FA was confirmed while the incorporation of HPL led to higher VEGF‐A expression by MC3T3‐E1 cells. Overall, the addition of HPL and FA to ADA‐GEL hydrogel results in a promising ink, which has potential for future biofabrication applications. [ABSTRACT FROM AUTHOR]

Hydrogel have been widely used to promote skin tissue regeneration and accelerate wound healing. The development of injectable hydrogels with multi‐functional integration is a priority, especially with antibacterial properties and cytocompatibility. Here, we reported a simple, and versatile method to fabricate a functional hydrogel with potential for wound dressing applications. The dopamine‐grafted gelatin (GT‐DA) and oxidized dextran (oxyglucan, ODex) were synthesized, and dipotassium glycyrrhizinate (DG) was in situ incorporated to fabricate the composite hydrogels (GDO) through the Schiff base reaction. SEM images revealed that hydrogel has a porous structure. By increasing the ratio of GT‐DA to ODex from 1 to 4, the storage modulus (G') and hydrogel network stability nearly doubled, reaching 900 Pa and 220% strain, respectively. The enhancement in mechanical properties could be attributed to the higher cross‐linking density resulting from increased Schiff base bonds in the GDO hydrogels. Furthermore, the GDO hydrogel exhibited antioxidant activity and antibacterial effects on Escherichia coli and Staphylococcus aureus. Moreover, the hydrogel demonstrated cytocompatibility after culturing with human umbilical vein endothelial cells (HUVECs). The results proved that the fabricated GDO hydrogels have the potential to be used as wound dressings. [ABSTRACT FROM AUTHOR]

ABSTRACT 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]

In order to improve the solubility of metallated monomers and product crystallinity, metal–covalent organic frameworks (MCOFs) are commonly prepared via high‐temperature sol‐vothermal synthesis. However, it hampers the direct extraction of crystallization evolution information. Exploring facile room‐temperature strategies for both synthesizing MCOFs and exploiting the crystallinity mechanism is extremely desired. Herein, by a novel single‐phase synthetic strategy, three MCOFs with different microstructure is rapidly prepared based on the Schiff base reaction between planarity‐tunable C3v monomers and metallated monomers at room temperature. Based on detailed time‐dependent experiments and theoretical calculations, it is found that there is a planarity‐tuned and competitive growth relationship between disordered structures and crystal nucleus for the first time. The high planarity of monomers boosts the formation of crystal nucleus and rapid growth, suppressing the forming of amorphous structures. In addition, the microenvironment effect on selective photocatalytic coupling of benzylamine (BA) is investigated. The strong donor‐acceptor (D‐A) MCOF exhibits efficient photocatalytic activity with a high conversion rate of 99% and high selectivity of 99% in 5 h under the 520 nm light irradiation. This work opens a new pathway to scalable and efficient synthesis of highly crystalline MCOFs. [ABSTRACT FROM AUTHOR]

Polymer membranes of a copolymer ligand (L) coordinated to tetra‐coordinated N,N'‐ethylene bis(salicylideneiminato) cobalt(II) at the fifth coordinating site of the center cobalt(II), Co(II)S‐L, are prepared to measure colorimetrically the color changes in response to rapid reversible oxygen binding simultaneously with slow oxidation under moist conditions to yield Co(III)S‐L. The chromaticity point observed in CIELAB is the endpoint of the vector sum of the unit vectors for Co(II)S‐L, O2‐Co(II)S‐L, and Co(III)S‐L, scaled by their respective abundance ratios: (1 − m)(1 − n), m(1 − n), and n, where m is the ratio of O2‐Co(II)S‐L to the sum of Co(II)S‐L and O2‐Co(II)S‐L and n is the ratio of Co(III)S‐L to the total of the three cobalt complexes. The observed limited area in CIELAB as a stoichiometric Euclidean space is supported by the following two different reaction processes of the polymer membranes: an oxygen‐binding reaction under several different partial pressures of oxygen supplied to the membranes in a short period, during which oxidation of the cobalt(II) complexes is negligible, and an oxidation reaction over a long period at a constant partial pressure of oxygen. The chromaticity points in both processes progress linearly in three different two‐dimensional coordinates: a*b*, a*L*, and b*L*. [ABSTRACT FROM AUTHOR]

We report the synthesis, structure, and characterization of two novel neptunyl complexes (NpO2L1 and NpO2L2) constructed from phenylene‐substituted benzyl ester bis(pyrrole)phenylenediamine (named "pyrrophen") ligands. In both cases, the neptunium center exists in the +6 oxidation state,. As our specific interest is in exploring the chemistry of neptunium compounds containing the linear neptunyl ion (NpO22+) through equatorially coordinating the metal by multidentate organic ligands, we have identified the differences that are likely to cause discrepancy between the two complexes by examining the ions and their coordinative environments through single‐crystal X‐ray crystallography, diffuse reflectance, and Raman spectroscopy. This is the first time pyrrophen has been utilized in Np chemistry and demonstrates a new platform to study 5 f electron participation and coordination. [ABSTRACT FROM AUTHOR]

In this work, we unveil a novel synthesis of bench stable Ni (II) complexes supported by tetradentate Schiff‐base ligands and the complexes were devoid of any phosphine or phosphine‐based ligand. These Ni‐complexes were successfully applied for the dehydrogenation of secondary alcohols for ketone and ketazine syntheses. Secondary alcohols with different functional groups were well tolerated during catalytic cycle. Moreover, we successfully extended this protocol for the synthesis of biologically significant ketones and ketazines. On the basis of various control experiments, probable reaction pathway was proposed, and an acceptorless alcohol dehydrogenation mechanism was suggested. [ABSTRACT FROM AUTHOR]

In this study, novel Schiff base, PTIEO and PABHP were synthesized using Phenyl Glyoxal as a major constituent and their structures were elucidated through modern spectroscopic techniques. Antioxidant assays were performed using DPPH and ABTS assays. Further, PTIEO and PABHP were subjected to in vitro biological evaluations against ESKAP pathogens. This investigation revealed significant antibacterial activity of both compounds, with MIC below 64 μg mL−1 against Staphylococcus aureus and 64 μg mL−1 against Acinetobacter baummanii. In molecular docking studies, PTIEO shows enhanced binding energy with Acinetobacter baumannii bacterial protein Diaminopimelate epimerase at −7.45 Kcal mol−1, while PABHP exhibited −8.32 Kcal mol−1 binding energy with NADH‐dependent enoyl‐ACP reductase. Additionally, PTIEO and PABHP demonstrated good binding energy with Sortase‐A of Staphylococcus aureus at −7.59 Kcal mol−1 and −8.75 Kcal mol−1, respectively. Moreover, antifungal capabilities of these compounds were evaluated against pathogenic fungi Candida Albicans, Candida Parapsilosis, and Candida tropicalis, highlighting their broad‐spectrum antimicrobial properties. Moreover, PABHP displayed cytotoxicity with an IC50 value of 23.50 μg mL−1, suggesting its safer administration. ADMET calculations were also performed to demonstrate their effectiveness. Overall, these experiments attribute to the significant therapeutic behavior of Schiff bases as comprehensive biomedical agents. [ABSTRACT FROM AUTHOR]

Malaria, a persistent and ancient adversary, continues to impact vast regions worldwide, afflicting millions and severely affecting human health and well‐being. Recently, despite significant progress in combating this parasitic disease, malaria remains a major global health concern, especially in areas with limited resources and vulnerable populations. Consequently, identifying and developing effective agents to combat malaria and its associated dysfunctions is essential therefore the two new Schiff base ligands incorporated Co(II), Ni(II), Cu(II) and Zn(II) ions were synthesized and thoroughly characterized. The synthesized compounds were assessed for in vitro anti‐malarial and antimicrobial efficacy, compounds (9, 10) demonstrated highest potential with IC50=1.08±0.09 to 1.18±0.04 μM against P. falciparum and MIC=0.0058 μmol/mL against C. albicans and E. coli, respectively. The complexes (5, 6) were effectively reduce mitigate oxidative stress with lowest IC50 value of 2.69±0.12 to 2.87±0.09 μM. Moreover, the biological findings were reinforced by a molecular docking investigation involving the potential compounds (2, 7–10) against dihydroorotate dehydrogenase and sterol 14‐alpha demethylase proteins which exposed complex's excellent biological response than their parent ligands. ADMET profiling was used to confirm the compounds' oral drug‐like features. This research offers promising prospects for future multi‐functional drug innovations targeting malaria, pathogenic infections, and oxidative stress. [ABSTRACT FROM AUTHOR]

The regeneration of hypoxia‐impaired chronic tissue defects has long been challenging, mainly due to the inefficiency of oxygenation and the limited biological activity of existing oxygen delivery systems in regulating dynamic tissue regeneration process. Herein, a novel polyphenol‐copper coordination strategy to fabricate bioactive superoxide dismutase‐catalase self‐cascade nanozymes (SalB‐CuNCs) is reported, which can serve as an in situ oxygenator and induce angiogenesis simultaneously. The copper‐phenolic hydroxyl coordination structure in SalB‐CuNCs plays a critical role in promoting the enzyme‐like cascade reaction via catechol‐mediated Cu valence state transition and substrate capture mechanism. Furthermore, after incorporating SalB‐CuNCs into a Schiff base hydrogel (COC@SalB‐Cu), the resulting system exhibits outstanding antioxidant and robust oxygenation effect in mitigating the hypoxic microenvironment. Benefiting from the intrinsic angiogenic activity of SalB and copper, COC@SalB‐Cu hydrogel can induce a more complete tube formation by up‐regulating the expression level of vascular endothelial growth factor (VEGF), platelet‐endothelial cell adhesion molecule‐1 (CD31), and endothelial nitric oxide synthase (eNOS). In vivo experiments further demonstrate that the COC@SalB‐Cu hydrogel can significantly restore the oxygen and blood supply, leading to fast tissue regeneration. The present strategy holds enormous promise for the treatment of hypoxia‐related chronic tissue defects and vascular injury in the field of regenerative medicine. [ABSTRACT FROM AUTHOR]

ABSTRACT 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]