Search Results (284)

Nutgall tree anthracnose, caused primarily by Colletotrichum species, acts as a primary bottleneck restricting the sustainable development of the Rhus chinensis industry. Developing green biocontrol strategies by screening molecular targets for novel fungicides is highly imperative. A strain designated as Serratia plymuthica WF63 was isolated from healthy R. chinensis tissues. The strain exhibited broad-spectrum antifungal activity and multiple plant growth-promoting (PGP) traits, including the production of protease, cellulase, and indole-3-acetic acid (IAA). In vivo experiments revealed that S. plymuthica strain WF63 achieved a biocontrol efficacy of over 50% against anthracnose pathogens (Colletotrichum nymphaeae and C. fioriniae) and demonstrated significant plant growth-promoting effects. Gas chromatography–mass spectrometry (GC-MS) analysis, combined with in vitro toxicity validation of pure compounds, identified hexahydro-2H-pyrido [1,2-a]pyrazin-3(4H)-one as a core antifungal component in the fermentation broth, with a half maximal effective concentration $\left(E{C}_{50}\right)$ of 133.88 mg·L⁻¹ against the target pathogen. These findings not only highlight S. plymuthica strain WF63 as a promising antifungal biological agent but also suggest that the specific nitrogen-containing heterocyclic compound may serve as a candidate scaffold for further fungicide optimization, pending comprehensive ecotoxicological evaluation. Full article

Quinoline derivatives constitute a privileged class of nitrogen-containing heterocycles with extensive applications in medicinal chemistry, agrochemicals, materials science, and functional organic materials. Owing to their broad biological and industrial relevance, the development of efficient, selective, and sustainable synthetic methodologies for quinoline construction remains an active area of research. This review provides a comprehensive overview of recent advances in quinoline synthesis, with particular emphasis on catalytic strategies aligned with the principles of green and sustainable chemistry. Classical transformations, including the Friedländer, Skraup, and Povarov reactions, are revisited in the context of modern catalytic developments that improve reaction efficiency, substrate scope, selectivity, and environmental compatibility. Special attention is devoted to homogeneous and heterogeneous catalytic systems based on both platinum-group and earth-abundant transition metals, highlighting the growing importance of borrowing-hydrogen and acceptorless dehydrogenative coupling methodologies. Recent progress in nanocatalysis, photocatalysis, multicomponent reactions, ionic-liquid-mediated transformations, and metal-free protocols is also critically discussed. Furthermore, solvent-free processes, microwave-assisted synthesis, and recyclable catalytic systems are examined as practical approaches toward minimizing waste generation and energy consumption. Mechanistic aspects, catalytic design principles, substrate limitations, and sustainability metrics are evaluated throughout the review to provide a critical perspective on current methodologies. Collectively, the advances summarized herein demonstrate the rapid evolution of quinoline synthesis toward more atom-economical, environmentally benign, and operationally efficient processes, while also identifying future opportunities for the development of next-generation catalytic platforms for quinoline-based heterocycle construction. Full article

This study evaluated how a lemon essential oil–rutin–chitosan coating (CS-LEO/NE-R), prepared from a 5:95 (v/v) lemon essential oil/rutin-containing nanoemulsion and a chitosan solution containing 1.5% chitosan, 1% acetic acid, and 5% glycerol, combined with controlled freezing-point storage preserves seasoned white snakehead fillets. Compared with controlled freezing-point storage alone, the combined treatment significantly inhibited oxidation, volatile nitrogen accumulation, texture softening, and microbial growth. On Day 10, the coating group recorded a total viable count of 4.98 log CFU/g, which was below the national limit (5 log CFU/g), whereas the control group went beyond this limit by Day 7. This extended the microbiological and physicochemical acceptability period by approximately 3 days under the present experimental conditions. Untargeted metabolomics revealed 2267 metabolites, and the differentially abundant ones mainly comprised amino acids, heterocyclic compounds, aldehydes, ketones, and esters. KEGG enrichment suggested that changes in linoleic acid metabolism, terpenoid related annotations, the actin cytoskeleton, and the phospholipase D signaling pathway were associated with delayed quality deterioration. This work provides a theoretical basis for the composite biopreservation of aquatic products. Full article

A series of substituted pyrrolo[2,3-d]pyrimidines was designed, synthesized, and evaluated in vitro against two protozoan parasites: Plasmodium falciparum and Trypanosoma brucei brucei. Pharmacological studies revealed antiprotozoal activity with IC₅₀ values in the submicromolar to micromolar range. Additionally, the in vitro cytotoxicity of these new compounds was assessed using human HepG2 cells. Among them, the pyrrolopyrimidine derivative 1d emerged as the most potent antimalarial compound, exhibiting a selectivity index (SI) of 600.81 against the P. falciparum chloroquine-resistant W2 strain. For the chloroquine-sensitive 3D7 strain, the most notable selectivity index (SI) was observed for pyrrolo[2,3-d]pyrimidine 1c, with a value of approximately 123. Furthermore, compound 1b demonstrated the most interesting activity against Trypanosoma brucei brucei, with an SI of 39.52, marking it as a promising trypanocidal agent. FRET melting assays confirmed that these nitrogen-containing heterocyclic compounds bind to telomeric G-quadruplexes in P. falciparum and Trypanosoma. However, no clear correlation was found between G-quadruplex binding and antiparasitic activity or selectivity, suggesting that G-quadruplex targeting is unlikely to be the main mechanism underlying cytotoxicity. Full article

Nitrogen-containing molecules are fundamental components of astrobiology and play a key role in planetary environments. These species are particularly important because they may serve as key precursors to prebiotic molecules and contribute to chemical complexity. Reactions involving the highly reactive species methylidyne (CH) play a key role in complex organic formation in astrochemical environments, yet their interactions with nitriles such as acetonitrile (CH₃CN) remain relatively unexplored. In this work, we investigate the reaction network of CH + CH₃CN using high-level quantum-chemical calculations with RRKM and microcanonical transition-state theories to characterize the relative energies of reactants, intermediates, transition states, and products to identify the most favorable reaction pathways. Our results reveal that the most energetically favorable reaction channels proceed via barrierless CH addition to the triple CN bond and three-membered ring opening or CH insertion into a C-H bond, followed by a hydrogen elimination to form acrylonitrile (C₂H₃CN). This route highlights an efficient pathway toward a molecule of astrobiological interest. Acrylonitrile is particularly significant due to its stability and dual functional groups, which enable molecular growth complexity, both in planetary atmospheres and on surfaces, under astrochemical conditions. In addition to acrylonitrile, we identified a few other competing channels leading to an isonitrile species, which emphasizes a previously unexplored aspect of isomerization chemistry in the atmospheric planetary science. These isonitrile products, while less abundant, provide insight to the diversity of nitrogen-containing molecules that may form in environments such as Titan’s atmosphere or the interstellar medium. In these environments, acrylonitrile may serve as a reactive precursor that facilitates cyclization and molecular growth, which enables the formation of nitrogen-containing polycyclic aromatic molecules and N-heterocycles. This, in turn, contributes to the emergence of larger, more complex organic species relevant to prebiotic chemistry and potential origin of life in our solar system. Full article

This study investigated the application of six machine learning regression algorithms such as Random Forest, CatBoost, K-Nearest Neighbours, XGBoost, LightGBM, and Gradient Boosting, paired with Molecular ACCess System (MACCS) key fingerprints for the quantitative prediction of aromatase (CYP19A1) inhibitory potency, expressed as pIC₅₀. A dataset of 187 compounds was assembled from the ChEMBL database (version 33, Target ID: CHEMBL1978) following by systematic data curation workflow encompassing duplicate removal, pIC₅₀ transformation, and activity-based filtering. Model performance was rigorously evaluated using an 80/20 stratified train/test split, 5-fold cross-validation, and Y-randomisation testing to ensure unbiased assessment of predictive generalisation. Feature selection via CatBoost permutation importance on the held-out test set identified the top 20 predictive MACCS keys from an initial 166-bit space, substantially reducing dimensionality and improving generalisation across all models. Among the algorithms evaluated, CatBoost trained on the top 20 features achieved the strongest test-set performance (R² = 0.693, RMSE = 0.794, MAE = 0.659) with the most stable cross-validation R² (0.062 ± 0.304), outperforming all other algorithms. Y-randomisation testing returned an empirical p-value of <0.01, confirming that model performance reflects genuine structure–activity relationships rather than statistical chance. Permutation importance and SHAP analysis identified nitrogen-containing heterocyclic fragments (MACCS_41, MACCS_145) and halide-bearing substructures (MACCS_109) as the primary structural determinants of aromatase inhibitory potency, consistent with established CYP19A1 pharmacophoric requirements. Application of the model to ten representative plasticizers demonstrated that the refined applicability domain (h* = 0.423) accommodated eight of the ten compounds, enabling reliable potency predictions across phthalate esters and bisphenol analogues. These findings establish a transparent and reproducible QSAR framework for first-tier endocrine disruption risk screening of plasticizers and highlight the importance of permutation-based feature selection and applicability domain assessment in QSAR model development. Full article

Miconazole is a commonly used imidazole antifungal drug with a broad spectrum of activity against Candida strains and other microorganisms. However, its poor solubility and low bioavailability have limited its use to topical infections. To overcome this limitation through the use of cocrystalization techniques, the present work focuses on the relatively less explored class of heterocyclic carboxylic acid coformers, containing two nitrogen atoms in the ring, aimed at developing alternative multicomponent forms of miconazole. Five new forms of miconazole were subjected to in-depth structural analysis, including an evaluation of the effect of hydrate formation. Furthermore, layered motifs in the supramolecular crystal architectures were subjected to qualitative and quantitative surface analysis using CSD-Particle. All new forms of miconazole were also characterized by FT-IR spectroscopy and thermogravimetric analysis. Water solubility was identified as the most important physicochemical property, and significant improvements were obtained for four of the five salts studied. Notably, the newly synthesized miconazole salts with heterocyclic (di)carboxylic acids exhibited high antifungal activity. The tested compounds effectively inhibited the growth of C. albicans and C. parapsilosis at concentrations several times lower than the parent drug and also showed activity against the important C. auris strain. Therefore, the obtained salts may constitute attractive alternatives to currently used antifungal therapies. Full article

In recent years, Marine Natural Products (MNPs) have emerged as a significant source for anticancer drug discovery, as many natural products can offer structural diversity, unique mechanisms of action, and relatively low toxicity. This article provides a systematic review of MNPs with reported anticancer activities from 2020 to 2024. These compounds are classified into seven major categories: terpenoids, alkaloids, sterols, polyketides, peptides and proteins, polysaccharides, and macrolides. For each category, we elaborate on the marine sources, structural identification, in vitro anticancer activity, and preliminary structure–activity relationships. We found that sponges and marine-derived fungi are the most abundant sources of highly active compounds. Furthermore, knowledge graph-based analysis reveals that oxygen- and nitrogen-containing heterocycles constitute the core pharmacophores, and target prediction further indicates that MNPs exert anticancer effects through coordinated modulation of a multi-target network involving kinases, proteasomes, and nuclear receptors. This review contributes significantly to a deeper understanding of recent advances (2020–2024) in MNPs and provides critical guidance for promoting the development of innovative anticancer drugs derived from marine resources. Full article

Cancers are intricate and multifactorial diseases. Despite progress in medicine, there are still some obstacles in their treatment due to drug resistance, the toxicity of combination therapy and lack of drug selectivity toward cancer cells. The solution to this may be multi-target directed ligands (MTDLs), which have gained more and more popularity over the years. This review presents a comprehensive overview of novel potential multi-targeted derivatives of nitrogen-containing heterocycles, as imidazole, pyrazole, 1,2,3-triazole and 1,2,4-triazole. The review gathers the selected literature from 2006 to 2026. The analysis focuses on the potency of the inhibitory activity of selected molecules against a variety of molecular targets, as well as on their interactions with protein binding sites. Additionally, the structure-activity relationship (SAR) studies within the collected series are included. The discussion may contribute to the development of new multi-target anticancer agents. Full article

A novel nitrogen-containing heterocyclic compound, 4-(6-Chloropyridin-3-yl)-6-cyclopropylpyrimidin-2-amine, was designed and synthesized using 6-chloropyridin-3-aldehyde and cyclopropyl methyl ketone as starting materials. The structure of the target compound was characterized by ¹H NMR, ¹³C NMR and HRMS, and the spectral data were consistent with the expected structure, confirming the correctness of the product. Full article

A heteroatom-rich pyridine-based adsorbent (Pyridine PC) was synthesized through a multicomponent strategy and structurally confirmed by ¹H/¹³C NMR spectroscopy and mass spectrometry. To further enhance adsorption activity and surface reactivity, waste-derived CuO nanoparticles were immobilized onto the porous heterocyclic framework, generating a sustainable CuO@Pyridine PC hybrid nanocomposite. Batch adsorption experiments demonstrate highly efficient removal of malachite green (MG) dye and Cd(II) ions from aqueous solutions. Kinetic analysis reveals that adsorption follows the pseudo-second-order model, while equilibrium data are best described by the Freundlich isotherm, indicating adsorption on heterogeneous surfaces. Thermodynamic parameters confirm that the adsorption processes are spontaneous and exothermic. Surface and structural characterization using SEM/EDX, elemental mapping analysis and FT-IR before and after adsorption verifies strong pollutant binding and highlights the role of nitrogen- and oxygen-containing functional groups as dominant interaction sites. BET measurements show that CuO incorporation increases surface area and pore volume, while zeta potential analysis indicates excellent colloidal stability of the composite in aqueous media. Consequently, the CuO-modified sorbent exhibits enhanced adsorption capacities, increasing from 169.8 to 176.13 mg g⁻¹ for MG and from 276.5 to 368 mg g⁻¹ for Cd(II). The adsorbent demonstrated effective pollutant removal from real wastewater. The adsorption mechanism involves synergistic interactions between functional groups in the Pyridine PC matrix and CuO nanoparticles, providing enhanced active binding sites. Full article

The co-pyrolysis of Chlorella vulgaris (CV) and Eucalyptus branches (EP) offers a promising strategy to enhance bio-oil yield, improve resource utilization efficiency, and alleviate environmental pressures. In this study, the microwave-assisted co-pyrolysis of CV and EP at a mass ratio of 2:1 was investigated, focusing on the catalytic performance of Ni-X (X = Mg, Cu, Fe) bimetallic modified HZSM-5 zeolites. The effects of these catalysts on pyrolysis characteristics, product distribution, and bio-oil composition were systematically evaluated. Experimental results showed that the 15% Ni-Cu/HZSM-5 catalyst exhibited the best catalytic performance, achieving the highest bio-oil yield of 16.83%; it also elevated the R_m to 0.0687 wt.%/s and reduced T_s to 2084 s. Composition analysis revealed that Ni-Cu/HZSM-5 significantly promoted the formation of hydrocarbons, increasing their relative content from 11.59% (C2E1 Group) to 28.92%, while effectively suppressing the formation of nitrogen-containing compounds, reducing their content by 5.05%. Based on these results, a possible reaction pathway is proposed in which the Ni-Cu/HZSM-5 catalyst may enhance heteroatom removal through hydrodeoxygenation (HDO) at the Ni-Cu sites, followed by cracking and aromatization at the HZSM-5 acid sites. This effect may be complemented by preferential adsorption of oxygenated intermediates over nitrogen-containing species, which could help suppress the formation of nitrogenous heterocycles. This work provides theoretical guidance for the application of bimetallic zeolite catalysts in microalgae/lignocellulose co-pyrolysis, alongside a viable pathway for valorizing Eucalyptus by-products to produce high-quality bio-oil. Full article

Understanding the adsorption mechanisms of anions onto functional monomers is crucial for various applications in environmental remediation and chemical separation. In this study, we investigated the interactions of ReO₄⁻, Cl⁻, SO₄²⁻, and F⁻ with several organic functional monomers featuring aliphatic chains, cyclic saturated or unsaturated rings, and NH/NH₂ functional groups through density functional theory calculations. Employing a rigorous multilevel optimization strategy, we explored the geometric and energetic features of their complexes, focusing on hydrogen bonding and anion–heterocycle interactions. Our results highlight the strong affinity of ReO₄⁻, Cl⁻, SO₄²⁻ for amine-type functional monomers, while also revealing the distinct interaction patterns of F⁻ with aromatic rings containing nitrogen. This comprehensive analysis elucidates diverse binding mechanisms, providing insights into designing effective adsorbents for selective anion capture. Full article

The synthesis of nitrogen-containing heterocycles remains a subject of significant interest due to their applications in medicinal chemistry and materials science. This paper describes the preparation of imidazo[1,2-a]pyridine using a catalytic system consisting of the deep eutectic solvent (DES) choline chloride (ChCl)–tartaric acid (1:2) and I₂ by reaction between 2-aminopyridines and chalcones (1,3-diphenylprop-2-en-1-ones). The proposed mechanism suggests the activation of the chalcone carbonyl by the DES, enhancing the polarization of the conjugated system which suffers electrophilic addition by I₂ to the C=C bond. The resulting intermediate undergoes a nucleophilic attack by 2-aminopyridine followed by cyclization and iodine-promoted oxidation and aromatization to yield the corresponding imidazo[1,2-a]pyridine products. The role of the DES is crucial, as it facilitates carbonyl activation through hydrogen bond interactions, stabilizes reactive intermediates, and promotes protonation–deprotonation steps, thereby eliminating the need for metal catalysts or toxic organic solvents. Theoretical calculations at the PM6 level of theory suggest that the DES acts as a catalyst in this reaction, due to the nature of its components enabling the development of more sustainable synthetic strategies. Full article

Tricholoma terreum, a mushroom rich in bioactive compounds, exhibits notable antioxidant and anticancer properties. Despite its traditional use, its effects on breast cancer metabolism remain underexplored. Here, we conducted comprehensive phytochemical and volatile organic compound profiling of T. terreum extracts and evaluated their cytotoxicity against MCF-7 breast cancer cells. Using SPME–GC–MS and HPLC, we identified a complex chemical matrix dominated by organic acids (acetic acid, 43.85%) and nitrogen-containing heterocyclics (2-acetylpyridine, 15.19%), alongside significant phenolic acids such as gallic acid and syringic acid. Biological assays indicated that the ethanol extract showed notable cytotoxic effects, reducing MCF-7 cell viability to 3.64% after 72 h, while higher viability was preserved in healthy CCD-1072sk fibroblast cells. Using cell viability assays, flow cytometry, and gene expression analysis, we found that ethanol extracts selectively reduced cancer cell viability, induced G0/G1 cell cycle arrest (71.92%), and promoted apoptosis. Mechanistically, treatment downregulated key nucleotide biosynthesis genes (DHFR, TK1) and the glycolytic enzyme gene (ENO1), while upregulating the oxidative stress response gene SLC7A11 (18.32-fold), suggesting disruption of cancer metabolic pathways. These findings reveal a metabolic reprogramming effect of T. terreum extracts, highlighting their potential as metabolism-targeted agents in breast cancer therapy. Further studies are warranted to validate these effects in vivo and isolate active constituents. Full article