Polyhydroquinoline is a privileged scaffold consisting of a 1,4-dihydropyridine moiety, which exhibits several pharmacological activities. The multicomponent approach for the synthesis of polyhydroquinolines involves a one-pot four-component condensation reaction of aldehyde, dimedone, ethylacetoacetate or ethylcyanoacetate and ammonium acetate. It involves protocols using various catalytic systems such as nanoparticles, organocatalysts, ionic liquids and inorganic materials. Biological functions as well as applications in other fields have increased interest in synthetic chemists towards the development of newer protocols for the construction of polyhydroquinolines. In this connection, an attempt has been made to summarize the recent methodologies for the synthesis of polyhydroquinolines in one article. The insights developed from this review will expand ideas of chemists for newer green synthetic strategies towards multicomponent synthesis of polyhydroquinolines.
Hypertension is a major cause of cardiovascular morbidity and mortality worldwide, necessitating the search for safe and effective therapeutic alternatives. Moringa oleifera Lam., a medicinal plant rich in bioactive phytochemicals, is traditionally used in cardiovascular management, but its effects under normotensive conditions remain insufficiently defined. This study evaluated the acute and sub-acute cardiovascular effects of M. oleifera leaf extract in normotensive rats. Wistar rats of both sexes received oral doses of 100, 200, or 400 mg/kg extract, while controls received acacia solution. Acute responses were assessed at 0, 1, 2, 4, and 8 h, and sub-acute effects over 28 days. Blood pressure, pulse rate, and mean arterial pressure were measured non-invasively. Cardiac tissues were examined histologically using haematoxylin and eosin staining. The extract produced mild, time- and dose-dependent cardiovascular modulation without statistically significant changes or sustained hypotension. Cardiac histoarchitecture remained largely preserved, with only mild, non-progressive vascular changes at higher doses. These findings indicate a favourable cardiovascular safety profile and support further evaluation in hypertensive models.
Anaemia remains a major public health challenge, often associated with oxidative stress and impaired erythropoiesis. This study investigated the in vivo antioxidant and hematinic potential of aqueous leaf extract of Moringa oleifera in phenylhydrazine-induced anaemic Wistar rats. Anaemia was induced using phenylhydrazine to generate oxidative damage and hemolysis, after which experimental animals were treated with graded doses of M. oleifera aqueous extract. Hematological parameters including packed cell volume, hemoglobin concentration, red blood cell count, and related indices were assessed to evaluate hematinic activity. In addition, antioxidant status was determined by measuring markers such as superoxide dismutase, catalase, reduced glutathione, and malondialdehyde levels. Results showed that treatment with M. oleifera extract significantly improved hematological indices and restored antioxidant enzyme activities while reducing lipid peroxidation in a dose-dependent manner when compared with untreated anaemic controls. These effects suggest enhanced erythropoietic activity and protection against oxidative stress. The findings demonstrate that aqueous extract of Moringa oleifera possesses notable antioxidant and hematinic properties, supporting its traditional use in the management of anaemia and oxidative stress-related conditions.
In this study, a new azo reagent, 4-((6-methoxybenzo[d]thiazol-2-yl) diazenyl)-3-hydroxy-2-naphthaldehyde (4-MTDHN), was synthesized and identified using UV-Vis, FTIR, 1H-NMR, and mass spectrometry. It was subsequently coupled with nickel ions to form an ion-pair complex, which was extracted using the cloud point extraction (CPE) method. The [Ni–(4-MTDHN)] structure was examined using the Job method; the molar ratio was found to be 1 : 1. The experimental parameters, like pH, the 4-MTDHN concentration, surfactant, metal ions, heating duration, and temperature, were optimized. Also, the thermodynamic parameters of the CPE were determined: ΔHex = +0.164 kJ mol–1, ΔGex = –68.819 kJ mol–1, and ΔSex = +195.421 J mol–1 K–1. An endothermic process is indicated by this method. The good analytical figures were obtained, such as a limit of detection (LOD) of 0.02 µg L–1, a limit of quantification (LOQ) of 0.86 µg L–1, a preconcentration factor (PF) of 12.5, an enrichment factor (EF) of 43.82, and an RSD of 0.017
Ethidium bromide is extensively used as a fluorescent marker in biotechnology and molecular biology laboratories. Due to its mutagenic and carcinogenic properties, effluents containing ethidium bromide represent a significant environmental concern and require appropriate treatment prior to disposal. In the present study, the photocatalytic degradation of ethidium bromide using iron(III) oxide (Fe2O3) as a photocatalyst was investigated to assess its effectiveness and environmental safety. Photocatalytic experiments were conducted under controlled irradiation conditions, and the degradation process was monitored through spectroscopic analysis. The results indicate a noticeable reduction in the concentration of ethidium bromide during photocatalytic treatment. However, further examination of the treated effluent revealed the formation of degradation products that exhibit higher toxicity than the parent dye. This observation suggests that photocatalytic discoloration does not necessarily correspond to complete mineralization or detoxification of the compound. An environmental risk assessment was performed to evaluate the suitability of Fe2O3-assisted photocatalysis as a treatment strategy for laboratory waste containing ethidium bromide. The assessment demonstrates that although the photocatalytic process facilitates partial degradation of the dye, the persistence and potential harmful effects of the resulting intermediates limit its applicability as a standalone treatment method. The presence of toxic transformation products highlights the need for caution when relying solely on photocatalytic approaches for hazardous dye removal. Overall, the study concludes that Fe2O3-mediated photocatalytic treatment alone is insufficient to ensure the environmental safety of ethidium bromide–containing laboratory effluents. The process should be supplemented with appropriate tertiary treatment techniques to achieve effective detoxification prior to discharge into the environment.
The advancement of nanotechnology has revolutionized cancer therapy, with iron oxide (Fe3O4) nanoparticles emerging as a pivotal platform for magnetically targeted drug delivery. This review critically examines the functionalization and biomedical applications of Fe3O4 nanoparticles, focusing on their design, targeting capabilities, and therapeutic potential. Surface engineering strategies—including polymer coatings, silica shells, and ligand conjugation—enhance nanoparticle stability and facilitate functional modifications in biological environments. Magnetic targeting enables precise accumulation at tumor sites under external fields, improving therapeutic efficacy while minimizing off-target toxicity. The conjugation of Fe3O4 nanoparticles with anticancer biomolecules such as chemotherapeutic drugs, small interfering RNA (siRNA), and therapeutic proteins achieves synergistic and site-specific treatment effects. Both in vitro and in vivo studies are evaluated to highlight their efficiency in cellular uptake, biodistribution, and tumor suppression. Safety and biocompatibility are addressed, emphasizing strategies to mitigate adverse effects and potential toxicities. Despite their promise, challenges—including nanoparticle aggregation, immunogenicity, and clinical translation – remain. The review concludes by identifying future directions, including multifunctional platforms, stimuli-responsive release systems, and integration with diagnostic modalities, aimed at advancing Fe3O4-based nanocarriers toward clinical application.
2-Aminopyridine-3-carbonitrile derivatives exhibit high reactivity and can be used as building blocks for further modification and creation of more functionalized derivatives. The main reactions are associated either with reactions of the amino group: alkylation, acylation, condensation and diazotization; or with reactions of the nitrile group: reduction, hydrolysis, addition of nucleophilic reagents. The presence of several reaction centers in the 2-aminopyridine-3-carbonitrile molecule allows the production of condensed derivatives. This review covers the works available from 1978 to 2023, revealing the possibilities of using substituted 2-aminopyridine-3-carbonitriles in organic synthesis.
An Erratum to this paper has been published: https://doi.org/10.1134/S2634827626220010
Liquid emulsions and gas-liquid mixtures are actively used in industrial applications requiring efficient heat and mass transfer. During metalworking, cutting tools are often cooled using special liquid emulsions. During electrochemical treatment of metals, heat is released, and gas bubbles and sludge are removed from the treatment area using an electrolyte stream. Modeling physical processes helps to better understand their essence, especially if the model and the actual process have similar characteristics. Simple models describe fundamental physical phenomena and are expressed through dimensionless similarity criteria based on theoretical assumptions and empirical data. The Labuntsov theory of advanced boiling of a homoge neous liquid at a solid wall was used to analyze the boiling of emulsions of liquids with a low-boiling dispersed phase. The calculated dependence obtained for the emulsion was compared with experimental data reported. The results of the study showed that heat transfer in the emulsion depends on the concentration of the dispersed phase and occurs in two modes with different mechanisms of bubble boiling. The data obtained are in good agreement with the results of measurements of the heat flux density during boiling of water-oil emulsions. Numerical methods and specialized software for computational fluid dynamics are used to solve such problems, which makes it possible to optimize the operation of various devices and systems.
Benzimidazole is a recognized nitrogenous heterocycle renowned for its many pharmacological and biological properties. In medicinal chemistry, its core structure is a privileged scaffold, and many of its derivatives have promising therapeutic applications. This review presents a comprehensive analysis of biological activities, physicochemical characteristics, and synthetic approaches of benzimidazole and its derivatives. The study also highlights the utility of these substances in ongoing drug discovery initiatives. Both conventional and current synthetic approaches, including eco-friendly and green chemistry approaches, were covered in a thorough literature review. Benzimidazole’s physicochemical characteristics were evaluated in order to determine how it affected biological activity. A range of pharmacological profiles from published experimental studies was analyzed. Several traditional and environmentally friendly synthetic pathways for benzimidazole derivatives have been established. These compounds display a broad spectrum of biological activity, encompassing antibacterial, antiviral, antiulcer, anticonvulsant, antiprotozoal, and anticancer effects. Important structural characteristics that affect their pharmacokinetics and bioactivity are revealed by the physicochemical analysis. Benzimidazole is still a useful building block for the creation of new medicinal substances. It is a major focus in therapeutic chemistry due to its broad biological properties, chemical stability, and ease of synthetic accessibility. The present state and prospects for benzimidazole-based drug design and development are discussed in this review.
The emergence of multidrug resistance and the urgent need for new therapeutic agents have driven the development of novel heterocyclic scaffolds with broad-spectrum bioactivity. In this study, a series of imidazo[1,2-a]pyrimidine–Schiff base hybrids were synthesized through a multi-step protocol starting from 2-acetylthiophene. The synthesized compounds were structurally characterized using 1H NMR, 13C NMR, FTIR, and mass spectrometry. Biological screening demonstrated that several derivatives exhibited promising antimicrobial, antifungal, antimalarial, and antitubercular activities. Among them, five compounds emerged as the most active candidates, one of them showed potent antifungal and antimalarial efficacy, while another one displayed notable antitubercular activity. Antimalarial assays revealed sub-micromolar IC50 values (0.62–0.70 µg/mL) for the most active compounds, highlighting their strong inhibitory potential against Plasmodium falciparum. To complement the experimental studies, molecular docking was performed against the target protein (PDB ID: 1KZN) using AutoDock Vina. Two compounds with docking scores –8.5 kcal/mol–8.1 kcal/mol showed the highest binding affinities, supported by extensive hydrophobic interactions with key residues (ARG A:76, GLU A:50, THR A:165, ILE A:78). The docking results correlated well with experimental activity, providing mechanistic insight into the potential modes of action. Overall, the integrated biological and computational findings highlight this imidazo[1,2-a]pyrimidine–Schiff base series as promising scaffolds for the development of new antimicrobial, antifungal, antimalarial, and antitubercular agents. These results provide a strong foundation for further structural optimization, ADMET profiling, and in vivo validation of the most active candidates.
Polyhydroquinoline structural scaffolds, N-containing heterocyclic compounds, are of significant interest in both organic chemistry and medicinal biology, notably as the core structure in calcium channel blockers – a crucial class of drugs for treating cardiovascular and Alzheimer’s diseases. In recent years, the development of catalysts for their synthesis has advanced rapidly. Within this field, catalyst recovery and reusability have become central research priorities, driving the exploration of efficient strategies for facile catalyst separation from reaction media. Such methods present a sustainable alternative to traditional separation techniques that are often time-consuming and resource intensive. This review focuses on the synthesis, surface modification, and catalytic applications of nanoparticles and other advanced catalysts in the preparation of polyhydroquinoline derivatives.
Intumescent (thermally expanding) coatings are among the most effective, technologically advanced, and aesthetically viable solutions for fireproofing steel and wooden structures. When exposed to fire, these coatings undergo a series of complex chemical transformations, culminating in the formation of a low-thermal-conductivity charred foam layer. This process is driven by the thermo-oxidative degradation of a carefully engineered formulation. In addition to typical components—such as blowing agents and char-forming compounds—the polymeric binder is critical. It serves a dual role: first, as the medium facilitating the thermo-oxidative reactions, and second, as the structural matrix for the expanded char formed during initial intumescence. To regulate decomposition and supress active combustion, flame retardants are integrated into the formulation. This review examines the fundamental operating principles of fire-protective intumescent coatings and surveys the range of binders and flame retardants employed in their compositions.
Nanomedicine has emerged as a powerful strategy in cancer therapy, enabling targeted drug delivery, enhanced imaging, and improved therapeutic indices through nanoscale engineering. Despite these advantages, increasing evidence highlights unintended biological effects associated with nanoparticle exposure that raise important safety concerns. This review critically examines the adverse consequences of nanomedicine in oncology, with emphasis on mechanistic pathways underlying nanotoxicity. Key processes discussed include oxidative stress generation, mitochondrial dysfunction, lysosomal membrane permeabilization, immune activation, genotoxicity, and dysregulation of redox-sensitive signalling pathways such as NF-κB and MAPKs. The influence of nanoparticle physicochemical properties—composition, size, surface chemistry, and biodistribution—on toxicological outcomes is also evaluated. By integrating findings from in vitro and in vivo studies, this review highlights the dualistic nature of nanomedicine, where therapeutic efficacy may coexist with off-target toxicity and long-term biological risks. Understanding these mechanisms is critical for the rational design of safer nanomaterials and for advancing the responsible clinical translation of nanomedicine-based cancer therapies.
The transition to a circular economy necessitates sustainable analytical methods for valorizing agricultural waste, yet the quantification of silica in biomass remains hampered by matrix interferences and the environmental burden of conventional techniques. Herein, we introduce a novel merging-zone flow injection analysis (M-FIA) system for the green and rapid quantification of silica in rice husk. The method innovatively integrates molybdenum blue chemistry with synchronized standard addition, enabling real-time correction of phosphate interference without toxic masking agents. Systematically optimized via design of experiments, the method achieves a low detection limit of 2 μg mL–1, excellent precision (RSD < 1.2
In recent years, there has been a tremendous increase in environmental pollution, so this paper has been conveying the synthesis, mechanism and different applications of the degradation of organic pollutants with the use of inorganic metal oxide nanomaterials which show different properties and many methods have been discussed for the degradation of the wastewater treatment. These nanomaterials provide an alternative sustainable approach for the treatment of wastewater contaminated with organic pollutants, especially for pharmaceutical waste. The proposed review articles provide the latest data on the use of inorganic metal and metal oxide nanomaterial in the treatment of wastewater contaminated with pharmaceutical waste which is very useful for the researcher to develop new strategies for the formulation of new particles and their applications in this field.
This review summarizes recent advances in the synthesis and application of quantum dots (QDs) for the corrosion protection of metallic materials and for corrosion monitoring. Particular attention is paid to the dual functionality of these nanomaterials as effective corrosion inhibitors and as highly sensitive fluorescent sensors capable of early detection of corrosion processes. The mechanisms of the inhibitive action of QDs in acidic and saline media are discussed, including adsorption, formation of protective films, and blocking of anodic and cathodic reactions. Data on the influence of chemical composition, particle size, and type of doping (N-, S-, and P-doped dots, carbon dots (CDs)) on inhibition efficiency—reaching up to 97
Cycloalkylphenols are widely used as raw materials in the production of various industrial products, such as surfactants, detergents, phenolic resins, polymer additives, and lubricants. The current global demand for these organic compounds is estimated to be approximately 400 000 t/year. Given their significant importance in practical applications, the development of effective and environmentally friendly methods for synthesizing cycloalkylphenols, the use of efficient catalysts in these reactions, and the determination of optimal conditions for carrying out these processes are urgent tasks in the fields of petrochemistry and organic synthesis at this stage. In the presented work, we review the results of studies in the field of cycloalkylation of phenols and their derivatives, and we also present the findings from our own research.
Based on quantum chemical calculations using DFT model chemistries at the M06/TZVP, B3PW91/TZVP, and OPBE/TZVP levels, we have demonstrated the potential existence of (666)macrotricyclic complexes, each containing a doubly deprotonated form of subphthalocyanine (H2SPc) in the inner coordination sphere with a metal-to-ligand ratio M(II) : SPc2– = 1 : 1. The main geometric parameters of the molecular structures of these coordination compounds are presented, revealing that the chelate MN3 unit adopts a trigonal-pyramidal geometry with a substantial deviation from coplanarity (in most cases, exceeding 90°). The 6-membered metal chelate and 5-membered non-chelate rings in these complexes are also non-planar, although their deviations from coplanarity are considerably smaller, not surpassing 20° and 5°, respectively. Furthermore, the complexes can be divided into two groups. In the first group (M = Ti, V, Mn, Co, Ni, Cu, Zn) all M–N bond lengths, bond angles (NMN) in the chelate unit MN3, and non-valence angles between the coordinated nitrogen atoms are virtually up identical. In contrast, the second group (M = Cr, Fe) exhibits noticeable differences in these parameters. Good agreement between the structural data obtained using the three above-mentioned DFT method variants is established, both qualitatively and quantitatively. NBO analysis data for these complexes are presented; it is noted that according to each of the DFT methods used, the ground state of each of the complexes under consideration has the same spin multiplicity as the ground state of the corresponding central ion M(II). The standard thermodynamic parameters of formation (standard enthalpy ΔfH0, entropy S_f^0 , and Gibbs energy ΔfG0) for these metal macrocyclic compounds were also calculated.
Triphenylbismuth dicarboxylate Ph3Bi[OC(O)C6H3F2-2,3]2 was synthesized by an oxidative addition reaction between triphenylbismuth and 2,3-difluorobenzoic acid in the presence of tert-butyl hydroperoxide in diethyl ether. The compound was identified by IR spectroscopy and X-ray diffraction analysis. According to X-ray diffraction data, the bismuth atoms in the crystals of the compound [C32H21O4F4Bi, FW is 754.47; triclinic system, space group P 1̅ ; cell parameters: a = 9.023(4) Å, b = 11.208(4) Å, c = 14.784(6) Å; α = 70.166(13)°, β = 86.68(3)°, γ = 82.698(14)°; V = 1394.9(10) Å3; crystal size 0.36 × 0.14 × 0.09 mm; index ranges –15 ≤ h ≤ 15, –18 ≤ k ≤ 19, –25 ≤ l ≤ 25; total reflections 91 795; independent reflections 14 244; Rint 0.0426; GOOF 1.010; R1 = 0.0315, wR2 = 0.0613; residual electron density 1.12/–0.91 e/Å3] have a distorted trigonal bipyramidal coordination with the oxygen atoms of the carboxylate ligands in axial positions (the axial angle is 172.19(6)°). The sum of the CBiC bond angles in the equatorial plane is 359.92(9)°. The Bi–O distances are 2.291(2) and 2.250(2) Å, the Bi–C bond lengths vary in the range 2.193(3)–2.216(2) Å. The bismuth atom deviates from of the equatorial plane [C3] by 0.033 Å. In the structure of the compound, Bi⋅⋅⋅O(=C) intramolecular contacts are observed, which is significantly less than the sum of the van der Waals radii of Bi and O atoms (3.9 Å). The spatial crystal structure of the compound is formed due to the presence of hydrogen bonds such as H⋅⋅⋅O(=C), H⋅⋅⋅F, and CH⋅⋅⋅π interactions. Atomic coordinates, bond lengths, and bond angles have been deposited in the Cambridge Crystallographic Data Center (CCDC no. 1981641; deposit@ccdc.cam.ac.uk; https://www.ccdc.cam.ac.uk ).
