Search Results (1,361)

The growing demand for sustainable and efficient synthetic methodologies has brought nanocatalysis to the forefront of modern organic chemistry, particularly in the construction of heterocyclic compounds through multicomponent reactions (MCRs). Among various nanocatalysts, calcium oxide nanoparticles (CaO NPs) have gained significant attention because of their strong basicity, thermal stability, low toxicity, and cost-effectiveness. This review provides a comprehensive account of the recent strategies using CaO NPs as heterogeneous catalysts for the green synthesis of nitrogen- and oxygen-containing heterocycles through MCRs. Key reactions such as Biginelli, Hantzsch, and pyran annulations are discussed in detail, with emphasis on atom economy, reaction conditions, product yields, and catalyst reusability. In many instances, CaO NPs have enabled solvent-free or aqueous protocols with high efficiency and reduced reaction times, often under mild conditions. Mechanistic aspects are analyzed to highlight the catalytic role of surface basic sites in facilitating condensation and cyclization steps. The performance of CaO NPs is also compared with other oxide nanocatalysts, showcasing their benefits from green metrics evaluation like E-factor and turnover frequency. Despite significant progress, challenges remain in areas such as asymmetric catalysis, industrial scalability, and catalytic stability under continuous use. To address these gaps, future directions involving doped CaO nanomaterials, hybrid composites, and mechanochemical approaches are proposed. This review aims to provide a focused and critical perspective on CaO NP-catalyzed MCRs, offering insights that may guide further innovations in sustainable heterocyclic synthesis. Full article

Natural Deep Eutectic Solvents (NADES) were synthesized from food-grade components and evaluated as green extractants for the simultaneous recovery and liquid chromatography coupled to quadrupole-Orbitrap mass spectrometry (LC–Q-Orbitrap-MS) analysis of biopesticide residues in a complex matrix like honey. Conventional solid–liquid extraction (SLE) was applied, initially using choline chloride-2,3-butanediol (1:4, molar ratio) as the NADES extractant solvent, before systematically evaluating other NADES formulations. Extraction parameters, such as time (10 min, 20 min, and 30 min), technique (rotary mixing vs. sonication), and NADES composition, namely lactic acid–glucose–water (LGH, 5:1:9, molar ratio), lactic acid–glycerol–water (LGLH, 1:1:3, molar ratio), urea–glycerol–water (UGLH, 1:1:2, molar ratio), and choline chloride–2,3-butanediol (ChClBt, 1:4, molar ratio), were systematically optimized. Rotating agitation for 10 min yielded the highest overall recoveries and was therefore selected as the optimal extraction time. Rotary shaking was chosen over sonication due to its superior performance across both simple and complex matrices. Among the NADES tested, UGLH proved to be the most effective composition for the honey matrix. The analytical method was validated for the honey matrix. Linearity showed excellent performance across the tested concentration range, with R² values above 0.95 for all analytes. Matrix effects were within ±20% for nearly half of the compounds, while a few exhibited moderate matrix enhancement. Recoveries ranged from 50.1% to 120.5% at 500 µg/kg and 1000 µg/kg, demonstrating acceptable extraction performance. Intra-day and inter-day precision showed relative standard deviations (RSDs) below 20% for most analytes. Limits of quantification (LOQs) were established at 500 µg/kg for eight compounds based on recovery and precision criteria. These results confirm the suitability of the proposed NADES-based method for sensitive and reliable analysis of biopesticide residues in honey. When compared to conventional extraction methods, the proposed NADES-based protocol proved to be a greener alternative, achieving the highest AGREEprep score due to its use of non-toxic solvents, lower waste generation, and overall sustainability. Full article

This research provides a comprehensive evaluation of the phytochemical composition, antioxidant potential, and biological properties of four plant species with longstanding use in ethnobotanical traditions: Calendula officinalis, Mentha × piperita, Urtica dioica, and Juglans regia. Plant extracts were obtained using a range of solvent systems and subsequently analyzed for their content of total polyphenols, flavonoids, and phenolic acids. Ultra-high-performance liquid chromatography coupled with mass spectrometry (UHPLC-MS) enabled the accurate identification and quantification of major polyphenolic constituents. The antioxidant capacity was assessed through a series of in vitro assays, and elemental analysis was conducted to determine microelement content. To evaluate potential ecological implications, acute toxicity was tested using Daphnia magna, while phytotoxic effects were also examined. The results demonstrate pronounced antioxidant activity along with notable biocidal and soil-enhancing properties. These findings underscore the potential of such plant-based formulations as sustainable alternatives to conventional agrochemicals and highlight the relevance of integrating traditional botanical knowledge with modern strategies for enhancing soil quality, crop performance, and environmental sustainability. Full article

The paper presents the effect of an organic solvent on the efficiency of vapor condensation from pyrolysis processes applied to agricultural waste, with the intention of optimizing the trapping procedure for more volatile components. Therefore, the effect of the use of acetone in the vapor trapping system on the yield and composition of liquid fractions (bio-oils) obtained from the pyrolysis of selected agricultural waste, including corn, tomato, and tobacco, was investigated. The focus was placed on evaluating how solvents influence the quality, yield, and composition of bio-oil, as well as whether they are necessary in the pyrolysis process. Acetone, a polar solvent with low human toxicity and the possibility of regeneration after pyrolysis, was selected for bio-oil condensation due to its effectiveness in dissolving polar compounds formed during the pyrolysis of lignocellulosic biomass. Pyrolysis was conducted at 400 and 500 °C for 30 min, to collect light and heavy fractions, which were subsequently analyzed to assess acetone’s influence. The results showed that acetone positively affected corn bio-oil yield (from 44.57% without acetone to 52.13% with acetone) and improved quality by reducing moisture (from 61.82% to 12.83%) and oxygen content (from 86.50% to 47.10%). An increase in calorific value was also observed in both corn varieties, while the effect was minimal in tobacco and nearly negligible in tomato. The obtained parameter values indicated that satisfactory results can also be achieved without the use of a solvent, representing a step toward simplified pyrolysis. GC-MS analysis confirmed that phenols and their derivatives were the dominant compounds, while FTIR analysis verified the presence of functional groups of the identified compounds. Increasing the temperature generally increased both the yield and calorific value of most samples. Light and heavy fractions were separated during condensation to improve collection efficiency and enable better quality control. Although this step adds complexity and potential contamination risks, it allows more effective utilization of the fractions. These results provide a valuable foundation for optimizing the valorization of agricultural waste through pyrolysis-based biofuel production. Full article

The inhibition mechanism and binding properties of four phenolic acids (ferulic acid (FA), p-coumaric acid (CA), gallic acid (GA), and protocatechuic acid (PA)) on xanthine oxidase (XOD) were investigated. All four phenolic acids acted via a mixed inhibition pattern, mainly influencing the hydrophobic regions and secondary conformation of XOD through hydrophobic bonding and hydrophobic association. Molecular dynamics simulations exhibited that the complexes of XOD with FA and CA revealed smaller radii of gyration (Rg) and solvent-accessible surface areas (SASA), along with lower variability in root-mean-square deviation (RMSD) and root-mean-square fluctuation (RMSF), collectively indicating greater structural stability. FA, CA, and PA significantly reduced uric acid (UA) concentration in the 25–100 μM range. Although GA only reduced UA levels in cell models at 25 μM, this effect was likely due to its larger polar surface area, which limits cellular uptake. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) evaluation suggested that these phenolic acids have potential for development. Full article

The search for bioactive compounds against chronic diseases such as cancer and diabetes includes curcuminoids as promising scaffolds. Here, we report the synthesis of a family of curcuminoid analogue compounds with an extended unsaturated central chain, as follows: difluoroboron complex 1, the enolised curcuminoid 2, and its homoleptic copper complex 3, in moderate to good yields (68–90%). Additionally, their β-cyclodextrin (BCD) association complexes, 4 and 5, were prepared through a mechanochemical method and characterised by spectroscopic techniques. Complete ¹H and ¹³C NMR assignments and NOESY correlations revealed unique solvent effects on the conformational disposition of compound 2, while the copper complex 3 displayed the highest extinction coefficient (1.20 × 10⁵ M⁻¹·cm⁻¹). Furthermore, the authentication of the polymorph of 1 and the new crystal structures of 2 and 3, determined by single-crystal X-ray analysis, were highlighted. Although the copper complex 3 initially exhibited the lowest a-glucosidase inhibitory activity (IC₅₀ > 100 µM), it showed a significant increase (IC₅₀ = 36.27 µM) upon association with BCD, reaching values comparable to the free ligand (IC₅₀ = 45.63 µM). Compounds 1–5 were non-toxic to healthy cells (COS-7), but compound 5 stands out as a promising candidate against this metabolic condition. Full article

The growing need for environmentally friendly separation processes has motivated the search for alternative solvents to petroleum-derived chemicals for the recovery of biosynthesized products. Although effective, conventional petroleum-based solvents pose major environmental and sustainability concerns, including pollution, ecotoxicity, human health risks, and high costs and energy demands for recycling. Consequently, current research and industrial practice increasingly focus on their replacement with safer and more sustainable alternatives. This study investigates the use of natural oils (i.e., grapeseed, sweet almond, and flaxseed oils) as renewable, biodegradable, and non-toxic diluents in reactive extraction systems for the separation of 7-aminocephalosporanic acid (7-ACA). The combination of these oils with tri-n-octylamine (TOA) as extractant enabled high extraction efficiencies, exceeding 50%. The system comprising 120 g/L tri-n-octylamine in grapeseed oil, an aqueous phase pH of 4.5, a contact time of 1 min, and a temperature of 25 °C resulted in a 7-ACA extraction efficiency of 63.4%. Slope analysis suggests that complex formation likely involves approximately one molecule each of tri-n-octylamine and 7-ACA, although the apparent order of the amine is reduced in systems using natural oils. This study highlights the potential of natural oil-based reactive extraction as a scalable and environmentally friendly method for 7-ACA separation, aligning with the principles of green chemistry and environmental biotechnology. Full article

Alkanna tinctoria (L.) Tausch is a valuable medicinal plant known for its root-derived hydroxynaphthoquinone enantiomers, alkannin/shikonin (A/S), which exhibit significant pharmaceutical and cosmeceutical potential. However, its limited natural distribution and overharvesting pose conservation challenges, necessitating sustainable cultivation and extraction strategies. The application of Natural Deep Eutectic Solvents (NaDESs) has garnered significant attention as sustainable alternatives to conventional solvents. However, their toxicity in living plant systems remains largely unexplored. This study presents the successful establishment of an ex situ hydroponic cultivation system using the nutrient film technique (NFT) to grow A. tinctoria under greenhouse conditions. The system promoted plant acclimatization, vigorous root development, and initial production of A/S derivatives. In parallel, the toxicity evaluation of a bio-based NaDES, LeG_5_20 (levulinic acid–glucose, 5:1, with 20% water), applied as a circulating medium, was assessed. Physiological stress responses of the plants to NaDES circulation were assessed through non-destructive measurements, including stomatal resistance, photosynthetic and transpiration rates, and sub-stomatal CO₂ concentration. Short-term (24 min) exposure to NaDES showed no significant adverse effects, while longer exposures (4–8 h) induced marked stress symptoms and loss of leaf area. These findings demonstrate the feasibility of integrating green hydroponic systems with eco-friendly extraction solvents and provide a framework for further optimization of plant age, solvent exposure time, and system design to enable sustainable metabolite recovery without plant destruction. Full article

Despite the widespread use of dithiocarbamate fungicides such as maneb, mancozeb, metiram, propineb, thiram, and ziram detected, according to EU legislation, via common degradation product carbon disulfide (CS₂), recent and comprehensive reviews on analytical methods for their determination in plant-based foods are lacking. Given the well-documented toxicity shown by the experimental model for these pesticides, including neurotoxicity and endocrine disruption, harmonized and reliable analytical protocols are crucial for food safety monitoring and regulatory compliance. Dithiocarbamates, beyond CS₂ release, have been associated with immunotoxicity, thyroid dysfunction, and potential carcinogenicity, raising further concern regarding chronic dietary exposure. Their metabolites may disrupt enzymatic activity and oxidative balance, enhancing systemic toxicity. Early methods, had limited sensitivity, poor reproducibility, and relied on hazardous solvents, reducing practical value. Although later advancements improved detection limits, modern procedures, including those proposed by the European Union Reference Laboratory (EURL), still show limitations. The EURL-recommended protocol involves acid hydrolysis using concentrated HCl, extraction with isooctane, heating to 85 °C, and rapid ice-bath cooling, which poses environmental concerns. Recovery efficiency remains inconsistent in some cases, and reproducibility within commodity groups is poor. This review discusses the status of methods for determining dithiocarbamates as individual compounds and via CS₂ moiety. Full article

This study developed a gas chromatography–tandem mass spectrometry (GC-MS/MS) method for detecting dinotefuran residues in fruits and vegetables. The modified extraction procedure employed solvent conversion for GC-MS/MS compatibility, achieving a linear range of 0.001–2.0 mg/kg (r² > 0.999), a LOD of 0.003 mg/kg, and a LOQ of 0.01 mg/kg. Recovery rates ranged from 88.2% to 104.5% (RSD: 3.5–5.8%). The analysis of 18 commercial samples from Weifang, China, revealed the highest residues in nectarines (0.12 mg/kg) and lowest residues in cucumbers (0.02 mg/kg), with the dietary exposure risk assessment indicating hazard quotients well below safety thresholds. The literature review showed that dinotefuran has a shorter soil half-life (10–30 days) than most neonicotinoids, a low adsorption coefficient (Koc 30–50), high leaching potential, and significant toxicity to pollinators (LD₅₀ = 0.023 μg/bee). The validated method provides reliable detection across diverse matrices, while the environmental behavior analysis highlights the need for the careful management of dinotefuran applications to minimize ecological impacts despite its favorable degradation profile compared to other neonicotinoids. Full article

With the rapid industrialization, excessive reliance on fossil fuels has resulted in energy crises and environmental pollution, driving the search for sustainable alternatives. Biomass-derived resources have emerged as promising candidates to replace fossil-based feedstocks. Among these, furfural (FF) serves as a key platform molecule that can be catalytically hydrogenated to various high-value chemicals, with furfuryl alcohol (FA) representing one of the most valuable products. Currently, Cr-based catalysts remain predominant for the selective hydrogenation of FF to FA. However, the severe environmental toxicity of Cr necessitates urgent development of alternative Cr-free catalytic systems. This study systematically reviews recent advances in FF hydrogenation to FA, providing an in-depth discussion of reaction mechanisms, including adsorption configurations, solvent effects, and side reactions, as well as a comprehensive analysis of structure–activity relationships, involving active metal, support, promoter, and preparation methods. Furthermore, we evaluate the application of the advanced characterization techniques for monitoring the reaction processes. Finally, we propose the future research directions: (1) designing efficient and stable non-noble metal catalysts and (2) elucidating reaction mechanisms via the combined in situ characterization and theoretical calculations. These efforts would facilitate the academic understanding and industrial implementation of the FF-to-FA conversion process. Full article

Carbon dioxide (CO₂) capture using alkanolamines remains the most mature technology, yet faces challenges including solvent loss, high regeneration energy and equipment corrosion. Ionic liquids (ILs) are proposed as alternatives, but their high viscosity and production costs hinder industrial use. Thus, blending ILs with amines offers a promising approach. This work presents new experimental data for aqueous blends of 1-butyl-3-methylimidazolium hydrogen sulfate, $\left[\mathrm{B}\mathrm{m}\mathrm{i}{\mathrm{m}}^{+}\right]\left[\mathrm{H}\mathrm{S}{\mathrm{O}}_4^{-}\right],$ with 2-amino-2-methyl-1-propanol (AMP) and 3-(methylamino)propylamine (MAPA) and for choline glycine, $\left[\mathrm{C}{\mathrm{h}}^{+}\right]\left[\mathrm{G}\mathrm{l}{\mathrm{y}}^{-}\right]$, with AMP, modeled using the modified Kent–Eisenberg approach. It was shown that substituting a portion of the amine with $\left[\mathrm{B}\mathrm{m}\mathrm{i}{\mathrm{m}}^{+}\right]\left[\mathrm{H}\mathrm{S}{\mathrm{O}}_4^{-}\right]$ reduces CO₂ uptake per mole of amine due to the lower solution’s basicity, despite the added sites for physical absorption. In contrast, the replacement of an amine portion with $\left[\mathrm{C}{\mathrm{h}}^{+}\right]\left[\mathrm{G}\mathrm{l}{\mathrm{y}}^{-}\right]$ enhances both physical and chemical interactions, leading to increased CO₂ solubility per mole of amine. Finally, replacing a small portion of water with $\left[\mathrm{C}{\mathrm{h}}^{+}\right]\left[\mathrm{G}\mathrm{l}{\mathrm{y}}^{-}\right]$ does not significantly alter the bulk CO₂ solubility (moles of CO₂ per kg of solvent) but lowers the solvent’s vapor pressure. Given the non-toxic nature of $\left[\mathrm{C}{\mathrm{h}}^{+}\right]\left[\mathrm{G}\mathrm{l}{\mathrm{y}}^{-}\right]$, the resulting solvent poses no added environmental risk. Model predictions agree well with experimental data (deviations of 2.0–11.6%) and indicate low unreacted amine content at CO₂ partial pressures of 1–10 kPa for carbamate-forming amines, i.e., $\left[\mathrm{G}\mathrm{l}{\mathrm{y}}^{-}\right]$, and MAPA. Consequently, at higher CO₂ partial pressures, the solubility increases due to carbamate hydrolysis and molecular CO₂ dissolution. Full article

The main objective of the study was to choose the best salicylic acid-based monomers through in silico research to improve the antibacterial effects of dental prostheses, refine the synthesis process of such monomers, and examine their antibacterial and antifungal properties in vitro, forecast the long-term stability in an oral biological environment using molecular docking software and synthesizing new copolymers. Based on their strong antibacterial activity and low toxicity compared to other derivatives, the allyl ester of salicylic acid (AESA) and the allyl ester of acetylsalicylic acid (AEASA) were chosen as the study objects. Salicylic and acetylsalicylic acids were esterified with allyl alcohol and allyl bromide in a variety of solvents and temperatures to synthesize AESA and AEASA. The optimal conditions were identified with a yield of 78%. IR spectroscopy was used to confirm the chemical structure of synthesized molecules. In the presence of peroxybenzoyl, the regularities of the polymerization process between the obtained monomer and oligoethylene macromonomer (PEMM) were examined. To obtain new antibacterial oligomers containing a salicylic group and to study their physico-chemical properties, a technology for obtaining the copolymers of AESA with PEMM was developed, and their physical, mechanical, and antimicrobial properties were studied. Full article

A novel process for the synthesis of binder-free, porous nickel/polythiophene-functionalized sulfur (Ni/S-PTh) composite cathodes for lithium–sulfur (Li–S) batteries is introduced in this paper. Initially, a polyvinyl butyl polymer scaffold is 3D printed, then coated with a graphite-based conducting layer, and, finally, it is pulse-plated for nickel deposition to produce a high-surface-area, mechanically stable current collector. S-PTh particles are afterwards co-deposited into the Ni matrix through composite electrodeposition. After the dissolution of the polymer template, the resulting self-standing electrodes still maintain porous structure with uniform sulfur distribution and a distinct transition between the dense Ni layer and the Ni/S-PTh composite layer. Electrochemical characterization of the Ni/S-PTh composite cathodes by galvanostatic cycling at C/10 rate results in an initial specific discharge capacity of ~1120 mAh·g⁻¹ and a specific capacity of ~910 mAh·g⁻¹ after 200 cycles, resulting in a high capacity retention of ~81 %. For our novel approach, no steps at high temperatures or toxic solvents are involved and the need for polymer binders and conductive additives is avoided. These results demonstrate the potential of composite electrodeposition in combination with 3D printing for producing sustainable, high-performance sulfur cathodes with tunable architecture. Full article

This study reports a dual green strategy for obtaining and stabilizing phytocomplexes from Sango radish and kale microgreens. Phytochemicals were isolated through supramolecular extraction, which generated an upper amphiphilic phase and a lower aqueous phase, enabling the recovery of both hydrophilic and lipophilic molecules without toxic solvents. The resulting phytocomplexes were encapsulated in nutriosomes, phospholipid vesicles enriched with the soluble dextrin Nutriose^® FM06, and compared with conventional liposomes. The vesicles displayed mean diameters ≤ 110 nm, polydispersity indices < 0.11, and zeta potentials around −40 mV. Retention of antioxidant activity reached up to 99%. Freeze-dried formulations maintained acceptable physicochemical properties and microbiological safety, while storage studies confirmed stability over six months. In vitro release tests showed a gradual release of phenolics and carotenoids, and simulated digestion experiments indicated that nutriosomes preserved up to 20% more antioxidant capacity than liposomes in the intestinal phase. These results demonstrate an environmentally responsible strategy to prepare phytocomplex-rich vesicles with improved stability and bioaccessibility. Further biological and in vivo studies are needed to substantiate potential nutritional or health-related benefits. Full article