Compounds, Volume 6, Issue 3 (September 2026) – 18 articles

Cyclic trimetaphosphate (cTmp) has been used as a prebiotically plausible compound to generate chemically activated nucleoside 5′-phosphates. While cTmp is mainly available as a trisodium salt, some experiments benefit from different cations. This study describes a simple procedure for exchanging the sodium with potassium in solution and isolating the K₃cTmp via ethanol precipitation, involving materials and equipment available in most biochemistry and molecular biology laboratories. Repeating the solution exchange and precipitation cycle four times allowed conversion of Na₃cTmp, with more than 99% ion exchange efficiency, into K₃cTmp, with an overall yield of 92%. This method has advantages over the usually used ion exchange chromatography and may be especially useful to prebiotic chemists working on cyclic trimetaphosphate. Analogous solution/precipitation ion exchange cycles could also be useful for ion exchange procedures of other compounds. Full article

Capsicum chinense Jacq. is an economically important chili pepper species characterized by a high capsaicinoid content, which contributes to its growing relevance in the food, pharmaceutical, and agricultural sectors. Although the chemistry and biological properties of capsaicinoids have been extensively investigated, available information remains fragmented, and no review has comprehensively integrated their botanical aspects, chemistry, biosynthesis, and insecticidal potential. This review provides an integrated overview of the major capsaicinoids of C. chinense, particularly capsaicin, dihydrocapsaicin, and nordihydrocapsaicin, focusing on their chemical composition, biosynthetic pathways, structure–activity relationships, and insecticidal properties and mechanisms. Particular emphasis is placed on the relationship between chemical structure and biological activity, as well as on the role of capsaicinoids as natural defense compounds and their insecticidal potential. Current evidence indicates that capsaicinoids exhibit insecticidal, repellent, and antifeedant activities through multiple mechanisms, including membrane disruption, oxidative stress induction, and interference with ion transport and neuronal signaling. Despite these promising findings, further field validation, methodological standardization, and optimized formulations are required. Overall, this review integrates the currently dispersed evidence on C. chinense capsaicinoids and highlights their potential as bioactive compounds for the development of more sustainable botanical insecticides. Full article

Kalanchoe delagoensis is a Crassulacean acid metabolism (CAM) succulent plant native to Madagascar that has spread as an aggressive invader across subtropical and Mediterranean regions. Research on this species has focused almost entirely on its cardiotoxic bufadienolides, leaving its phenolic fraction largely unexplored. Here, we profiled the phenolics of dried K. delagoensis leaves by reversed-phase liquid chromatography coupled with UV-Vis detection and electrospray ionisation high-resolution mass spectrometry (RPLC-ESI-HRMS). Two flavonoid diglycosides produced the most intense signals and were tentatively annotated by MS/MS analyses as quercetin and kaempferol deoxyhexoside-pentosides; the former shares the formula and fragmentation of quercetin 3-O-arabinopyranosyl-rhamnopyranoside (QAR), the chemical marker of the congeneric K. pinnata. The remaining MS/MS supported features form a single combinatorial family of flavonol glycosides on kaempferol, quercetin, and myricetin cores decorated with pentose, deoxyhexose, hexose, and hexuronic-acid units. Minor flavonol glycosides and mono- and digalloyl hexoses were also detected, and a malvidin-hexoside was putatively identified as a candidate contributor to the reddish leaf tint of the more sun-exposed leaves, supported by its absorption maximum at 520 nm and characteristic MS/MS spectrum. Folin-reactive compounds reached 47.0 ± 0.8 mg gallic acid equivalents per gram of dry leaf. These results extend the chemistry of K. delagoensis well beyond its bufadienolides, within the limits of a single clonal genotype and a single harvest. Full article

Powder X-ray diffraction (XRD) was used to determine the crystal structure of sodium chloride (NaCl) powder and to evaluate the accuracy with which a simple laboratory diffraction dataset can recover the crystallographic parameters of a well-known ionic solid. The diffraction profile collected over the angular interval 20° ≤ 2θ ≤ 90° contains nine indexed reflections at approximately 27.4°, 31.7°, 45.5°, 53.9°, 56.5°, 66.3°, 73.1°, 75.4°, and 84.1°. The sequence of squared-sine ratios, when referenced to the first reflection, is consistent with the allowed reflections of a face-centered cubic lattice. The observed indexing sequence is assigned to the (111), (200), (220), (311), (222), (400), (331), (420), and (422) reflections of the rock-salt structure. From Bragg analysis and the cubic interplanar-spacing relation, the average lattice parameter was determined as a = 5.642 ± 0.004 Å, in excellent agreement with the accepted value of approximately 5.640 Å for NaCl at ambient conditions. Peak broadening was further used to estimate an apparent Scherrer crystallite size of about 41.6 nm. This value should be interpreted as an XRD coherence length rather than as a direct particle size, because instrumental broadening and microstrain were not independently deconvoluted. A structure-factor and Lorentz–polarization analysis was used to rationalize the intensity hierarchy of the diffraction peaks and to explain why odd allowed reflections are weak but observable in NaCl owing to the difference between the Na⁺ and Cl⁻ scattering factors. The contribution of this work is methodological and educational: it reconstructs a transparent workflow connecting peak fitting, indexing, lattice-constant evaluation, crystallite-size estimation, and intensity interpretation within one coherent analysis. The incorporation of data-driven whole-pattern analysis significantly enhances structural validation, providing improved accuracy in lattice-parameter determination and a more reliable interpretation of crystallite size and microstrain effects. Full article

The novel complex [Fe^III(HL)(L)]·2dmf (1) was successfully synthesized by reacting iron chloride with dimethylformamide solution of the Schiff base ligand (H₂L). The ligand was prepared in situ through the condensation of 5-bromo-salicylaldehyde and benzhydrazide. The compound 1 was investigated by single crystal X-ray diffraction, IR spectroscopy, CASSCF/NEVPT2 and DFT theoretical calculations, revealing the high-spin (S = 5/2) state of Fe(III). The Hirshfeld Atom Refinement (HAR) of the crystal structure confirmed the sextet ground spin state of 1 through the comparison of R-factors and Hirshfeld deformation maps of the structures refined assuming high, indeterminate (S = 3/2) and low (S = 1/2) ground spin states. A series of basis sets and DFT functionals was screened, indicating that in most cases the combinations allow the correct determination of the ground state of 1. The def2-SVP double-zeta basis set combined with the GGA (Generalized Gradient Approximation) functional such as PBE or BP86 was found to be a sufficiently precise low-cost computational level. While further investigation is necessary, the results of the work tentatively suggest that the HAR could be successfully used for determination of the ground spin state of Fe(III) complexes even in the case of regular quality X-ray structures. Full article

We present a first-principles investigation of the layered ternary manganese tellurides ${\mathrm{MgMnTe}}_2$, ${\mathrm{Mg}}_3{\mathrm{MnTe}}_4$, and ${\mathrm{MgMn}}_3{\mathrm{Te}}_4$ using density functional theory with GGA and meta-GGA functionals. The optimized tetragonal structures (space group No. 115) satisfy the Born elastic stability criteria, with the structural derivatives exhibiting enhanced ductility. Unlike analogous alkali-based half-metals, these systems emerge as ferromagnetic semiconductors featuring substantial energy gaps in both spin channels. The calculated total spin magnetic moments are strict integers ($5 {\mathrm{\mu }}_{\mathrm{B}}$ for ${\mathrm{MgMnTe}}_2$ and ${\mathrm{Mg}}_3{\mathrm{MnTe}}_4$; $15 {\mathrm{\mu }}_{\mathrm{B}}$ for ${\mathrm{MgMn}}_3{\mathrm{Te}}_4$), driven predominantly by localized Mn d-states. Although advanced meta-GGA functionals modulate the magnitude of the predicted band gaps, the overarching electronic topology and magnetic character remain highly consistent. Ultimately, their calculated elastic response and intrinsic ferromagnetic semiconducting behavior identify these phases as candidates for further theoretical and experimental investigation for spintronic applications. Full article

Alzheimer’s disease (AD) is a complex neurodegenerative condition marked by a gradual decline in cognitive abilities, a reduction in acetylcholine (ACh) levels, and the accumulation of β-amyloid (Aβ) plaques. In a healthy brain, approximately 80% of ACh is broken down by acetylcholinesterase (AChE). Meanwhile, butyrylcholinesterase (BChE) serves a supportive function, gaining significance as AChE activity diminishes during the progression of Alzheimer’s disease. Modern therapeutic approaches focus on creating dual inhibitors of AChE and BChE that also aim to diminish Aβ-amyloidogenesis through interactions with the peripheral anionic site (PAS). This study combined fragment-based molecular design (CReM), AI-assisted retrosynthetic feasibility assessment, and in silico evaluation (docking, molecular dynamics, and ADMET profiling) to identify novel Donepezil derivatives as potential dual AChE/BChE inhibitors. A series of 10,000 derivatives were developed through computational methods and carefully assessed based on stringent drug-likeness, synthetic accessibility, and medicinal chemistry standards. This was succeeded by comprehensive ADMET profiling. Nine candidates were identified with predicted CNS pharmacokinetics, adequate toxicological profiles and reduced cytochrome P450 liabilities. Molecular docking yielded improved predicted binding affinities relative to Donepezil. Several derivatives, particularly D4 and D5, showed dual-site binding poses spanning both the catalytic gorge and the PAS. MD simulations indicated the stability of these poses over 100 ns. These computational results suggest that the proposed derivatives may preserve or improve upon Donepezil’s pharmacokinetic profile while offering potentially balanced AChE/BChE inhibition and anti-amyloidogenic activity, pending experimental validation. Full article

4-(2-Nitrobenzoyl)isoxazoles are readily available from 3,5-disubstituted 4-iodoisoxazoles through iodine–lithium exchange and trapping with 2-nitrobenzaldeyde, followed by Jones oxidation of the obtained secondary alcohols. Reductive ring transformation by means of treatment with iron in acetic acid gives 2-substituted 3-acyl-4-quinolones. The mechanism of the cyclization reaction was elucidated by using appropriately substituted isoxazole building blocks and 2D NMR investigation of the products. In contrast, catalytic hydrogenation leaves the isoxazole ring untouched, whereas reduction with NaBH₄/NiCl₂ gives 2-substituted 3-acylquinolines in an unprecedented reductive ring transformation. Full article

One of the most promising absorber materials for solar applications is copper zinc tin sulfide/selenide (CZTS), which has good optical properties and basic elements that are readily available, affordable, and environmentally acceptable. This study examines how pulse timing and current density affect the electrodeposition of Cu₂ZnSnS₄/Cu₂ZnSn(S,Se)₄ (CZTS/CZTSSe) thin films from a diluted electrolyte, including deposition quality, film configuration, elemental composition, crystallinity, and photovoltaic performance. It evaluates the impact of these factors on device performance, film properties, layer’s compactness, surface homogeneity, microcrack-free morphology, compositional homogeneity, crystallinity, and suitability for solar device manufacturing. Using a pulsed-current technique, CZTS precursor layers were electrodeposited in a low-concentration solution with periodic changes in current density of roughly 5.3–5.9 mA/cm² and pulse-on/off durations of 50/50, 100/100, and 250/250 ms. The deposited precursors were then added to fully built CZTS-based solar cell topologies after sulphurization or selenization. Structural characteristics were analyzed using X-ray diffraction (XRD), and composition and elemental distribution were assessed using energy-dispersive X-ray spectroscopy (EDS). Measurements of transmittance and reflectance were used to evaluate optical properties relevant to photovoltaic performance. In contrast to films deposited at higher current densities and longer off-times, moderate current densities combined with short off-times yield dense, microcrack-free films with improved crystallinity and near-stoichiometric Cu/(Zn + Sn), Zn/Sn, and chalcogen/metal ratios. Additionally, absorber layers with appropriate optical band gaps and improved device performance are produced by these optimized pulse parameters. Overall, the study shows that controlling pulse parameters in diluted electrolytes is a useful tactic for improving the quality of CZTS films and developing low-cost, solution-based fabrication techniques for high-performance CZTS solar cells. Full article

Ammonia (NH₃) is a compelling carbon-free hydrogen carrier. Its catalytic decomposition to produce a hydrogen/nitrogen (H₂/N₂) gas stream is central to the “NH₃-H₂” clean energy cycle, provided that residual NH₃ is removed to fuel-cell-grade purity downstream. This review integrates advances from the past five years across four major catalytic NH₃ decomposition pathways, encompassing conventional thermocatalysis, plasma-catalytic, photo(thermal), and electrically driven catalysis, within a unified mechanistic and practical framework, distinguishing it from existing single-pathway reviews. Noble metal catalysts, particularly Ru-based systems, achieve superior low-temperature activity through support engineering, promoter effects, and active-site construction. However, our analysis reveals that non-noble metal (Fe, Co, Ni) catalysts and their alloys, nitrides, and carbides have made substantial progress, with certain Co-based and bimetallic systems approaching Ru-level performance via interfacial oxygen vacancy engineering and electronic structure modulation. Emerging non-thermal routes effectively overcome thermodynamic barriers, enabling operation at temperatures 200–300 °C below conventional thermal requirements, though each faces distinct challenges in energy efficiency, stability, and scalability. Key challenges remaining across all pathways to practical implementation, including residual NH₃ removal and H₂ purification, catalyst deactivation and stability, heat management and energy efficiency, start-up/shut-down dynamics, as well as system integration and economics, are critically assessed. This review provides theoretical guidance and practical recommendations for developing scalable, low-temperature NH₃ decomposition technologies. Full article

Capsaicin, the main pungent capsaicinoid of Capsicum species, is often described as either an antioxidant or a pro-oxidant compound. This binary view is useful but does not fully explain its effects on cellular redox homeostasis. The response to capsaicin depends on dose, exposure time, cell type, metabolic state, mitochondrial function, antioxidant capacity, and TRPV1 expression. Capsaicin can modulate reactive oxygen species (ROS) production through TRPV1-dependent calcium signaling, but also through TRPV1-independent effects on plasma and mitochondrial membranes. These mechanisms influence mitochondrial bioenergetics, membrane potential, lipid peroxidation, and redox-sensitive signaling. Moderate ROS formation may support adaptive responses, including Nrf2 activation, mitochondrial quality control, and cellular stress tolerance. In contrast, persistent or excessive ROS accumulation may promote mitochondrial dysfunction, apoptosis, and oxidative cell death. Evidence for capsaicin-associated ferroptosis is emerging, particularly through changes in lipid peroxidation, glutathione availability, GPX4 activity, and SLC7A11 expression or activity, but remains incomplete in many models. This review summarizes current evidence on capsaicin-mediated ROS regulation, mitochondrial stress, TRPV1-dependent and TRPV1-independent mechanisms, ferroptosis-related pathways, and methodological challenges in oxidative stress assessment. Full article

The aim of this study was to determine the phenolic compound profile, antioxidant activity, antiproliferative activity, and toxicity of B. hindsiana. Ethanolic extractions of B. hindsiana leaves and stems were performed. The content of phenolic compounds was determined by the Folin–Ciocalteu method, while the phenolic compound profile was determined by UPLC-DAD. The antioxidant activity was evaluated using the DPPH, ABTS, ORAC, and FRAP methods. Antiproliferative activity was determined by the MTT method against HeLa, A549, and ARPE-19 cell lines. Acute toxicity was determined in Artemia salina. The results showed that the B. hindsiana leaf extract had the highest concentration of phenolic compounds, with quercetin-3-β-glucoside, rutin, and chlorogenic acid being the major compounds. Regarding antioxidant activity, the leaf extract showed a greater capacity (p < 0.05) to stabilize free radicals and reduce metals. For antiproliferative activity, the leaf extract also showed a greater capacity (p < 0.05) to inhibit the proliferation cancer cell lines. Finally, the B. hindsiana extracts presented an LC₅₀ value greater than 100 µg/mL in A. salina. Overall, the B. hindsiana extracts show promising biological potential, which may be associated with the phenolic compounds present, with low toxicity. This research is the first study reporting the phenolic compound profile and the leaf and stem biological activities from B. hindsiana. Full article

The genus Cynara is native to the Mediterranean region and is widely used in food and traditional medicine worldwide. Cynara is characterized by its diverse phytochemical composition, with sesquiterpene lactones, a subclass of terpenoids, being particularly distinctive. These compounds are naturally synthesized as defense mechanisms against herbivores and pathogens while acting as allelochemicals. The sesquiterpene lactones found in Cynara exhibit potential anticancer, anti-inflammatory, and antimicrobial activities. They also possess significant phytotoxic activity, making them promising natural bioherbicides for agricultural applications. The effective exploitation of these compounds requires the use of appropriate extraction solvents and techniques. Compared with conventional solvents and extraction methods, green solvents, including ionic liquids and deep eutectic solvents, together with modern extraction techniques, particularly ultrasound-assisted extraction, supercritical fluid extraction, and Naviglio extraction, have proven highly effective for their recovery. In addition, the application of elicitation strategies, such as salt stress, shading, hormones, and microbial biostimulants, has emerged as a promising approach for enhancing the production of these compounds during cultivation. Therefore, this review highlights Cynara as a valuable source of sesquiterpene lactones with broad applications in medicine and agriculture and provides guidance on technical approaches relevant to their extraction and the enhancement of their production. Full article

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder characterized by hyperandrogenism, insulin resistance, oxidative stress, and chronic low-grade inflammation, while conventional therapies are often limited by adverse effects and suboptimal adherence. This narrative review aims to evaluate the chemical composition and mechanistic effects of bioactive compounds derived from Allium species in the context of PCOS. A comprehensive analysis of the literature was performed, focusing on organosulfur compounds and polyphenols, with emphasis on their structure, reactivity, transformation pathways, and biological activity, integrating findings from preclinical and clinical studies. The evidence indicates that key compounds, including allicin, ajoene, and diallyl sulfides, exert biological effects through modulation of redox balance, inhibition of inflammation-related signaling, and regulation of insulin signaling pathways, while also influencing steroidogenesis and androgen synthesis. Polyphenolic compounds contribute primarily through antioxidant mechanisms related to their structural features. However, the current evidence remains limited by the scarcity of large-scale, long-term human clinical trials, particularly in women with PCOS, which restricts definitive conclusions regarding clinical efficacy, optimal dosing, safety, and long-term therapeutic applicability. Overall, Allium species represent a promising source of multitarget bioactive compounds for PCOS management, and understanding the chemical basis of their activity is essential for optimizing their therapeutic potential and guiding future research. Full article

Chamaecrista nigricans (Vahl) Greene leaves are investigated for their bioactive potential. Extracts were prepared using solvents of varying polarity to obtain a diverse range of compounds. The biological effectiveness of the extracts was analyzed against pathogens. Methanol extract showed antimicrobial activity. The methanol extract was subsequently partitioned with solvents of increasing polarity to obtain different fractions. Among these, the separated chloroform fraction was selected for further isolation. The separated chloroform fraction was subjected to column chromatography and visualized through thin-layer chromatography. Emodin was isolated and characterized by spectral analysis and compared with theoretical calculations using Gaussian software. Biological assessment was carried out using molecular docking. Among the cancer proteins, PDB ID: 7AH1 has a favourable binding energy (−3.42 kcal/mol) compared to other proteins. Emodin satisfies all criteria in ADMET profiling, supporting its potential as a promising candidate for further drug discovery. Full article

Zinc oxide (ZnO) nanoparticles are semiconductor nanomaterials widely used in biomedical, environmental, and catalytic applications due to their unique physicochemical properties. However, their increasing environmental release has raised concerns regarding potential toxicity in aquatic ecosystems. In this study, pure ZnO, 1% Au-modified ZnO, and 5% Au-modified ZnO nanoparticles were synthesized via a reflux-assisted method to evaluate the effects of Au incorporation on morphology, crystallinity, optical behavior, surface chemistry, and ecotoxicological responses, using Artemia salina as a marine bioindicator. Structural characterization was performed using high-resolution transmission electron microscopy (HRTEM), electron diffraction, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and energy-dispersive X ray spectroscopy (EDS) elemental mapping, while optical and surface analyses were conducted using UV–Vis and Fourier-transform infrared (FT-IR) spectroscopy. Although Au-rich domains were identified, the available data do not allow definitive determination of whether Au is incorporated into the ZnO lattice or present as surface-associated metallic Au. Increasing Au content promoted greater nanoparticle agglomeration and broader particle size distributions while preserving the hexagonal wurtzite ZnO crystalline structure. UV-Vis and FT-IR analyses demonstrated that Au modification altered the optical response and surface chemical environment of the nanoparticles. Toxicological evaluations revealed concentration- and time-dependent toxicity. Pure ZnO nanoparticles exhibited LC₅₀ values of 531.25 ppm after 24 h and 65.15 ppm after 48 h exposure. In contrast, 1% Au-modified ZnO nanoparticles showed reduced toxicity, whereas 5% Au-modified ZnO nanoparticles exhibited increased toxicity after prolonged exposure. These findings demonstrate that Au modification significantly influences the physicochemical properties and biological interactions of ZnO nanoparticles. Full article

Electrochemical methods for the direct reduction of alkyl esters have been understudied but provide a potential advantage for addressing specific waste streams given that such strategies often require only a minimal chemical profile. One such waste stream that could benefit from electrochemical remediation is poly(vinyl chloride) (PVC) plastics. PVC recycling often faces challenges due to the complexity of such waste. Solvent-based recycling methods pose several advantages for addressing post-use PVC; however, such methods are complicated by the high amounts of toxic legacy plasticizers (ortho-phthalates) present in PVC. A potential solution to addressing such phthalates is to address them electrochemically, coupled with recovery of the resulting valuable products. Presented herein is an optimized electrochemical method for ester activation that is leveraged to separate and recover the aromatic and alkyl components of ortho-phthalate plasticizers. The resulting aliphatic alcohols may be reused to prepare other non-toxic plasticizers. This electro-degradation method is demonstrated on six phthalates that have been identified to pose health concerns in addition to plasticizers recovered from commercial samples of PVC. Full article