Introduction: Encapsulated metal oxide nanocomposites actively engaged in heterocy-clic transformations represent a potent and adaptable notion in catalysis. The facile derivatization of metal oxide nanocomposites by surface modification has popularized them as versatile catalysts for domino heterocyclization. Methods: With the emergence of multicomponent domino reactions (MDRs) as frontier synthetic tools for medicinally relevant heterocycles, optimally satisfying one-step syntheses is the domain of current research. Result: The search for a suitable catalyst for the domino multiple bond-forming synthesis of me-dicinal heterocyclic scaffolds has become a central evolving theme. In particular, metal oxide nano-composites have drawn considerable attention as viable catalytic alternatives to conventional ma-terials because of their facile adaptability in stabilizing functional cores or activating surfaces. Discussion: This review discusses the catalytic potential of derivatized metal oxide nanocompo-sites immobilized into or supported on various materials (metals, inorganic and organic nanocom-posites, etc.) for domino heterocyclization. Conclusion: This review highlights how the encapsulation of moieties on the surface of metal oxide nanoparticles has improved their catalytic recovery and reusability, as well as product yield, espe-cially in domino synthesis. Furthermore, this review summarizes the domino synthesis of hetero-cycles with privileged medicinal scaffolds. The present review provides new insights into designing domino protocols that utilize metal oxide nanocomposites as vital catalysts for drug discovery at the industrial level.

Introduction: The imidazo[2,1-b]thiazole core structure has gained significant attention due to its biological activity in various bioactive compounds. Its derivatives exhibit antibacterial, anticancer, and anti-inflammatory properties. Based on an extensive literature review, the synthesis of novel imidazo[2,1-b]thiazole derivatives was undertaken to explore their antibacterial potential against resistant bacterial strains. Methods: The synthesis of the imidazo[2,1-b]thiazole derivatives was performed in three steps: Step 1: The reaction of 5-methylthiazol-2-amine with phenacyl bromide led to the formation of 2-methyl-6-phenylimidazo[2,1-b]thiazole. Step 2: This intermediate was then treated with N-bromo-succinimide (NBS) to form 5-bromo-2-methyl-6-phenylimidazo[2,1-b]thiazole. Step 3: The final derivatives, 5-bromo-2-methyl-6-phenylimidazo[2,1-b]thiazol-5-amine, were synthesized by fur-ther functionalization. The compounds were characterized using TLC, FTIR, 1H NMR, and ESI-MS. Their antibacterial activity was evaluated against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Candida albicans, and Aspergillus niger. Results: The derivatives 6a, 6b, 6i, and 6o exhibited strong antibacterial activity, especially against P. aeruginosa and S. aureus, with zones of inhibition comparable to ciprofloxacin. Compounds 6a, 6b, 6j, 6l, and 6o also showed potent activity against E. coli and B. subtilis. Conversely, compounds 6c, 6e, 6i, 6j, 6l, 6n, along with 6o, showed highly potent antifungal properties against C. albicans and A. niger. Discussion: The synthesized imidazo[2,1-b]thiazole derivatives demonstrated significant antibac-terial and antifungal activity, notably against resistant pathogens, showing promise as alternative therapies. However, the lack of in vivo and mechanistic investigations restricts findings, requiring more study for clinical confirmation. Conclusion: The synthesized imidazo[2,1-b]thiazole derivatives exhibited significant antibacterial properties, making them promising candidates for further development as antibacterial agents.

Background: Heterocyclic compounds emerged promising choice in drug discovery and clinical research. Among various heterocycles, 5-aryl-1,2,4-triazolidine-3-thione and 1,2,4-tri-azospiro-3-thione derivatives also showed important biological applications. Hence, organic chem-ists are striving to develop various catalytic routes for the construction of these derivatives. Method: The present work describes the eco-friendly synthesis of 5-aryl-1,2,4-triazolidine-3-thione (3a-o) and 1,2,4-triazospiro-3-thione (5p-u) via one-pot Multi-Component Reactions (MCRs) of substituted aromatic/heteroaromatic aldehyde, isatine and thiosemicarbazide in the presence of or-ganocatalysts Glutamic acid (Glu) under microwave irradiation. Additionally, the homogeneity of the selected compounds was confirmed through various spectroscopic techniques such as FT-IR, 1H- 13C-NMR, and LC-MS. Further, the drug-likeness was evaluated using SwissADME software and the anti-microbial activity of the selected derivatives were tested. Results: The reaction exhibits good tolerance towards various substituted aromatic/heteroaromatic aldehydes, isatine, and thiosemicarbazide, resulting in high yields of product isolation (86–92%). The computational ADMET properties of the prepared derivatives were evaluated for their drug-like properties, along with an assessment of Lipinski’s Rule of Five. Selected derivatives were also tested for their antimicrobial properties, showing comparable activities. Conclusion: Overall, this work describes a greener method synthesis of 5-aryl-1,2,4-triazolidine-3-thione derivatives (3a-o) and 1,2,4-triazospiro-3-thione derivatives (5p-u). The catalysts used are biodegradable, environmentally friendly organocatalysts that align with green chemistry principles. The reaction is accelerated by microwave irradiation in the presence of ethanol. The developed method is simple, allowing for easy separation of the catalyst using hot ethanol and enabling recy-cling up to three times without affecting product isolation. The developed protocol offers ad-vantages such as accessibility, cost-effectiveness, rapid reactions, mild atom economy, and elimi-nation of hazardous solvents and catalysts usage. Selected derivatives were screened for antimicro-bial activity, evaluated computationally for drug-likeness in silico, and adhered to Lipinski’s rule of five.

Background: Peroxidases are heme-containing oxidoreductase enzymes that have the potential to oxidise a wide range of organic and inorganic substances in the presence of hydrogen peroxide. Peroxidase has the capability to bioremediate various toxic and carcinogenic phenolic and nonphenolic compounds, various pollutants, and polychlorinated hydrocarbons. Different types of organic and inorganic chemicals change the rate of enzyme-catalysed reactions binding with enzyme or enzyme-substrate complex. Enzyme activators increase enzyme activity, while enzyme inhibitors decrease it. Enzyme inhibition involves either complete or partial prevention of the en-zymes' rate of reaction. We can use enzyme inhibitors to treat a variety of pathological disorders. Nowadays, enzyme inhibitors have become extremely beneficial compounds in our daily lives. They are commonly employed to cure diseases. Heavy metals, persistent inorganic chemical con-stituents, act as a form of poison to the enzyme’s reactivity. High amounts of heavy metals, such as Mn2+, Zn2+, and Fe2+, are poisonous even though they are crucial for plant physiology. Peroxidase production and activation are triggered by an excess of heavy metals as a defence system to scav-enge the hydrogen peroxide molecules produced by metal toxicity. The binding of some heavy metals with peroxidase alters the active site’s conformations and reduces the enzyme activity even at low concentrations. Due to the presence of metal ions changing the enzyme’s reactivity and the broad application of peroxidases, it is necessary to study peroxidase activity in the presence of heavy metals. Objective: The aim of this work was to study the enzyme activity in the presence of different heavy metal ions, such as Sr2+, Pb2+, Bi2+, Hg2+, Sn2+, Cd2+, Zn2+, Ni2+ Mo6+, etc. It also studied the nature of inhibition of peroxidase activity from radish sources in the presence of these metal ions. Methods: The effect of heavy metal ions on the activity of peroxidase was studied by means of a direct spectrophotometric assay that monitors at 470 nm with the decrease of tetraguaiacol for-mation from guaiacol in the presence of H2O2 and metal ions with time. The nature of inhibition was studied by comparing the control experiment and the experiment with the addition of two dif-ferent metal ion concentrations for the formation of tetraguaiacol at 470 nm from guaiacol in the presence of hydrogen peroxidase. Results: From this study, we have found that the metal ions like Mo6+, La2+, and Sr2+ inhibited the peroxidase enzyme very strongly, whereas the ions like Bi2+ and Cd2+ inhibited a bit weakly. The order of the inhibitory effect on radish peroxidase activity in the presence of different heavy metal ions was Pb2+ > Sr2+ > Hg2+ > Cd2+ > Bi2+=Sn2+ > Mo6+ > Zn2+ > Ni2+. The nature of inhibition on radish peroxidase activity of the Zn2+, Ni2+, and Sr2+ ions was found to be competitive; Cd2+, Pb2+, Hg2+, and Bi2+ ions were uncompetitive; and Sn2+ and Mo6+ ions were non-competitive. Conclusion: In this study, the response of the peroxidase to various heavy metal ions like divalent Cd2+, Bi2+, Hg2+, Sn2+, Pb2+, Cd2+, Zn2+, and Ni2+) and hexavalent Mo6+ was studied, and it was found that these heavy metal ions significantly inhibited the radish peroxidase activity. With a rise in the concentration of Sr2+, Pb2+, Bi2+, Hg2+, Sn2+, Cd2+, Zn2+, Ni2+ and Mo6+ ions, the radish pe-roxidase slowly lost its activity. These inhibitors bound to the radish peroxidase active sites and prevented the substrates from binding, and thus, they lost their tendency for binding substrates.

Introduction: This paper presents the synthesis, spectroscopic characterization, and computational modeling of 4-Bromoquinoline-2-carboxaldehyde (4-BQCA), an effective therapeutic compound. 4-BQCA, a quinoline derivative, has drawn interest because of its distinct chemical structure and its medical uses. Method: The chemical was produced with excellent yield and purity using a simple, repeatable reaction route. Density functional theory (DFT) studies were carried out to learn more about the compound's molecular characteristics, including its electronic structure, bonding, and stability. The structure and functional groups found in 4-BQCA were verified by spectroscopic investigation, which included UV-Vis, FT-IR, NMR, and mass spectrometry. Result: The compound's stability and advantageous electrical characteristics are highlighted by the results of both computational and experimental methods, indicating that it may find application in medication design and development. Conclusion: These results offer a starting point for further investigations into the biological activity and therapeutic effectiveness of 4-BQCA, indicating that it is a viable option for more study in pharmaceutical applications.

Introduction: Aromatization of dithioacetal derivatives is essential for the synthesis of bioactive compounds and drug design, playing a key role in pharmaceuticals, agrochemicals, and materials science. This study explores the synthesis and catalytic application of Cu2O nano hollow arrays in ring-expansion aromatization reactions of cyclic dithioacetal derivatives obtained from cyclohexanones. Methods: By using Cu2O nano hollow arrays prepared through molecular templates and a simple hydrothermal process, the electrophilicity of N-bromosaccharin was enhanced, allowing for efficient and selective production of aromatic compounds with yields ranging from 63-96%. Copper acetate is transformed into Cu2O nano hollow arrays in aqueous media, with polyvinylpyrrolidone acting as a capping agent and (+)-L-tartaric acid as a structure-directing surfactant and multidentate ligand. Results: The synthesized Cu2O nano hollow arrays were characterized using transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy-dispersive Xray spectroscopy (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) to verify their morphology, structure, and composition. Conclusion: This method not only offers a cost-effective and environmentally friendly approach to synthesizing Cu2O with unique nano hollow structures, but also demonstrates their efficacy as catalysts in organic synthesis, particularly in the rarely reported ring-expansion aromatization of cyclic dithioacetal derivatives of cyclohexanone, emphasizing their broader applicability in materials science and catalysis.

Background: The oxidation of aromatic primary alcohols is pivotal in organic synthesis, converting accessible starting materials into valuable intermediates. Traditional methods often rely on chromium-based reagents, which are hazardous and environmentally problematic. Ionic liquids, particularly those based on imidazolium cations, offer an attractive alternative due to their unique solvent properties and chemical stability. However, their application in oxidation reactions has been limited by challenges such as selectivity and efficiency. Recent advancements have focused on integrating chromium complexes into imidazolium ionic liquids to harness their catalytic potential. Understanding the catalytic efficiency and mechanistic insights of chromium-functionalized imidazolium di-cationic ionic liquids in alcohol oxidation is crucial for developing sustainable and efficient synthetic methodologies aiming to mitigate environmental impact and improve synthetic efficiency in organic chemistry. Objectives: The aim of this study was to synthesize, characterize, and explore the catalytic efficiency and mechanism of chromium-functionalized imidazolium di-cationic ionic liquids in the oxidation of aromatic primary alcohols. Methods: The oxidation of benzyl alcohol was optimized by varying solvent and temperature parameters. Initially, benzyl alcohol was subjected to oxidation in different solvents: water, DMF, ACN, chloroform, 1,2-dichloroethane, and DMSO at room temperature. Solvent effects were evaluated, with DMF, ACN, and DMSO yielding approximately 80% conversion to the desired aldehyde. Interestingly, DCE did not yield the desired aldehyde. CHCl3 emerged as the optimal solvent, achieving a high yield of 94% in minimal reaction time. Temperature optimization revealed that at room temperature, the reaction required 40 minutes to reach 94% yield. Increasing the temperature to 60 °C reduced the reaction time to 10 minutes while maintaining a high yield of 98%. Thus, 60 °C was identified as the optimal temperature for maximizing both yield and reaction speed. The methodological adjustments of solvent and temperature parameters provided crucial insights for optimizing the oxidation of benzyl alcohol using chromium-functionalized imidazolium di-cationic ionic liquid. Results: Reactions at room temperature required longer times and yielded lower product amounts compared to reactions conducted at higher temperatures. Importantly, no over-oxidation to carboxylic acids was observed. Electron-donating groups on aromatic alcohol substrates led to higher yields of aldehydes in shorter times. Conversely, substrates with electron-withdrawing groups showed reduced yields (84% to 92%) over extended periods. Primary aliphatic alcohols exhibited lower yields even with prolonged reaction times, while secondary alcohols yielded fewer oxidation products. Recycling [DIL]2+[Cr2O7]2- for four cycles showed decreased yields over successive uses, highlighting its potential for continuous catalytic use in alcohol oxidation. Conclusion: In this study, imidazolium-based Di-cationic ionic liquid [DIL]2+[Cr2O7]2- was synthesized, and its ionic liquid properties were demonstrated using TGA and DSC. Our developed catalyst efficiently converts primary aromatic alcohols to aldehydes using [DIL]2+[Cr2O7]2- or [DIL]2+[Cr2O7]2-/H5IO6, offering solvent-free rapid oxidation, catalyst recyclability for up to four cycles, and facile catalyst recovery. In comparison to other available oxidants, the developed protocol has a superior yield, ease of workup, ease of handling, and low hygroscopicity.

Background: Oxidation with peroxides plays an important role in dopamine catabolism, the disruption of which is responsible for the development of neurodegenerative diseases, including Parkinson';s disease. However, the mechanism of dopamine oxidation with peroxides has not been studied in detail, indicating the need to develop the kinetic patterns of the model reaction between dopamine hydrochloride and potassium peroxodisulfate. Objective: This article aims to establish the kinetic patterns of dopamine hydrochloride oxidation in the presence of potassium peroxodisulfate using the conductometry method to monitor the reaction rate. Methods: Conversion monitoring of dopamine hydrochloride and potassium peroxodisulfate was conducted by conductometry, which demonstrated high efficiency and was in good agreement with results independently obtained by potentiometry and UV spectroscopy. Results: The use of conductometry to monitor the current concentration of dopamine during its oxidation in the presence of peroxodisulfate anion is described for the first time. It was found that the activation energy of dopamine hydrochloride oxidation by potassium peroxodisulfate is approximately 60 kJ mol¹, and the reaction proceeds through a highly ordered transition state with an activation entropy of –127 J mol¹ K¹, under the first-order kinetic law. Conclusion: It is shown that dopamine acts as an activator of peroxide breakdown and can potentially serve as a source of radicals for the development of oxidative stress, which is one of the causes of neurodegenerative diseases, such as Parkinson';s disease. To explain the first order of the reaction and the small value of the pre-exponential factor, an assumption was made about the intermediate formation of charge-transfer complexes between dopamine and the peroxodisulfate anion, as well as about the pronounced hydration of the transition state formed when these reagents approach each other.

Background: Drug-resistant microorganisms are a major concern, particularly as more strains develop resistance to various antimicrobial agents. Some microbes are currently immune to all antibiotics. Consequently, it is imperative to develop novel drugs that maintain their effective-ness. The benzimidazole nucleus can be found in a wide variety of heterocyclic compounds in na-ture. Numerous investigations have been conducted on the physiological effects of molecules con-taining this moiety. Method: Some more recent benzimidazole analogues were synthesized through the synthetic stages of o-phenylene diamine with 6-bromo-3,4-dihydro-2H-chroman-2-carboxylic acid, followed by various electrophiles, in the search for new antibacterial and antifungal compounds with improved efficacy. 1H NMR, IR, and mass spectral data were used to determine the structures of these recently synthesized compounds. For their antibacterial and antifungal activities, all the produced com-pounds were tested. Besides their biological activities, these newly synthesized compounds were also docked into the active pocket of Dihydrofolate Reductase and Sterol 14-alpha demethylase to predict their binding modes concerning antibacterial and antifungal activities, respectively. More-over, these predictions would be utilized for the exploration of the mechanism of action on selected enzyme subunits. objective: Find out significant antimicrobial agents Result: Synthesis of 2-(6-bromochroman-2-yl)-1H-benzo[d]imidazole (4a-4y) derivatives was done using the classical Philipins condition. Spectral analysis revealed their structures. Amongst the synthesized scaffolds (4a-4y), target compounds 4r and 4w were active when compared with ciprofloxacin. Compound 4j was found to be highly active compared to clotrimazole. Ligands 4w and 4e exhibited better binding energy on Dihydro Folate Reductase and Sterol 14-alpha demethyl-ase (-7.1899 kcal/mol and -8.72613 kcal/mol) enzymes, respectively. Conclusion: The current investigation may have shown that the produced compounds differ from one another, regardless of their structure or observable biological activity. In the quest for a new group of antibacterial and antifungal molecules, these compounds may be useful to society.