Compounds

Aged green tea leaves, particularly from Shan Tuyet trees, represent an underutilized source of catechins—key antioxidant compounds with known health benefits. This study aims to optimize and compare three green extraction methods—Hot Water Extraction (HWE), Ultrasound-Assisted Extraction (UAE), and Ethanol–Water Extraction (EthE)—for catechin recovery from mature tea leaves. A Box–Behnken design (BBD) under Response Surface Methodology (RSM) was used to evaluate the effects of different extraction conditions. Total catechin content was quantified by HPLC, and antioxidant activities were measured using DPPH, FRAP, ORAC, and cellular antioxidant activity (CAA) assays. Results showed that while UAE and HWE produced total catechin yields of 206.0 mg/g and 202.0 mg/g, respectively, their biological efficacy was profoundly different. HWE, operating at a higher temperature (82 °C), induced significant thermal degradation, evidenced by high levels of catechin epimerization (EGCG/GCG ratio = 3.62) and hydrolysis. This loss of structural integrity resulted in the lowest cellular antioxidant activity (CAA) of 98.3 µmol QE/g. In contrast, the optimized UAE process (78 °C, 55 min, 290 W) preserved catechin stereochemistry (EGCG/GCG ratio = 9.86), yielding the highest CAA (185.2 µmol QE/g). These findings demonstrate that UAE acts as the optimal green strategy for producing high-yield, functionally superior extracts from mature tea leaves. Full article

Biofouling by mussels is responsible for serious economic losses worldwide. In Argentina, Limnoperna fortunei (Dunker, 1857) and Brachidontes rodriguezii (d’Orbigny, 1842) are common and abundant bivalve species of great interest, inhabiting freshwater and marine coasts, respectively. Both species are considered fouling pests for coastal industrial facilities that use untreated water as part of their processes. To chemically control mussel biofouling, it is necessary to find efficient and environmentally friendly non-biocidal compounds. In this work, we report the antifouling activity of three phenolic compounds (hydroquinone, resorcinol, and catechol) and their respective acetylated derivatives against L. fortunei and B. rodriguezii mussels. Classic ecotoxicity tests with Artemia salina were also performed. Acetylated phenolic compounds were synthesized in the laboratory by sustainable chemistry procedures. Results revealed the importance of hydroquinone, resorcinol, and catechol and their diacetylated derivatives for preventing the settlement of both these mussels, in a non-biocide way. Ecotoxicity bioassays revealed that these compounds were not toxic, with the exception of resorcinol. We propose the incorporation of these compounds in solution into closed circuits and water sprinkler anti-fire systems to prevent the settlement of L. fortunei and their inclusion in antifouling paints to prevent the settlement of B. rodriguezii. These results highlight a new friendly alternative for controlling mussels. Full article

Nucleobases play diverse structural and functional roles in biological systems. Understanding the fundamental properties of nucleobases is important for their applications as chemical probes of nucleic acid function. As the nucleobases are modified to tune their fluorescence or binding properties, their physical properties such as pK_a may also change. Unlike the canonical nucleobases, modified nucleobases are less well understood in terms of their acid-base properties. Previously, theoretical pK_a values of canonical, naturally modified, and aza-/deaza-modified nucleobases were determined. In this study, the theoretical pK_a values for 25 different fluorescent modified nucleobases (55 total pK_a values) were calculated by using an ab initio quantum mechanical method employing the B3LYP density functional with 6-31+G(d,p) basis set along with an implicit–explicit solvation model. The results of these computations are compared to known experimental pK_a values. The ability to estimate theoretical pK_a values will be beneficial for further development and applications of fluorescent nucleobases. Full article

Organophosphate pesticides are among the most persistent and toxic contaminants in aquatic environments, requiring effective strategies for detection and remediation. In this work, density functional theory (DFT) calculations were employed to investigate the adsorption of nine representative organophosphates (glyphosate, malathion, diazinon, azinphos-methyl, fenitrothion, parathion-methyl, disulfoton, tokuthion, and ethoprophos) on mercaptobenzothiazole disulfide (MBTS) and MBTS-functionalized graphene (G–MBTS). All simulations were performed in aqueous solution using the SMD solvation model with dispersion corrections and counterpoise correction for basis set superposition error. MBTS alone displayed a range of affinities, suggesting potential selectivity across the organophosphates, with adsorption energies ranging from 0.27 to 1.05 eV, malathion being the strongest binder and glyphosate the weakest. Anchoring of MBTS to graphene was found to be highly favorable (1.26 eV), but the key advantage is producing stable adsorption platforms that promote planar orientations and $\pi$–$\pi$/dispersive interactions. But the key advantage is not stronger binding but the tuning of interfacial electronic properties: all G–MBTS–OP complexes show uniform, narrow HOMO-LUMO gaps (∼0.79 eV) and systematically larger charge redistribution. These features are expected to enhance electrochemical readout even when adsorption strength was comparable or slightly lower (0.47–0.88 eV) relative to MBTS alone. A Quantum Theory of Atoms in Molecules (QTAIM) analysis of the G–MBTS–malathion complex revealed a dual stabilization mechanism: multiple weak C–H⋯$\pi$ interactions with graphene combined with stronger S⋯O and hydrogen-bonding interactions with MBTS. These results advance the molecular-level understanding of pesticide–surface interactions and highlight MBTS-functionalized graphene as a promising platform for the selective detection of organophosphates in water. Full article

Boron-dipyrromethene (BODIPY) has attracted extensive research attention in recent years due to its excellent photophysical properties, good chemical stability, and structural tunability, demonstrating broad application in fields such as fluorescence imaging, electroluminescence, biosensing and medical diagnostics. Researchers have extensively studied the synthesis, properties, and applications of BODIPY derivatives. This review summarizes five synthetic methods for the BODIPY core, with comparative analysis of their respective advantages, limitations and applicable scopes, aiming to provide valuable references for the future design and synthesis of BODIPY derivatives. Full article

Low-crystalline hydroxyapatite was synthesized from an aqueous solution of calcium chloride (CaCl₂)_, and a mixed-anionic (HPO₄²⁻ и CO₃²⁻) aqueous solution prepared from potassium hydrophosphate trihydrate (K₂HPO₄ 3Н₂О), and potassium carbonate (K₂CO₃). The interaction of K₂CO₃ and K₂HPO₄ salts during synthesis from a mixed-anionic solution in the reaction zone without additional regulation provided the pH level necessary for the synthesis of hydroxyapatite. For comparison, as references, powders were also synthesized from an aqueous solution of CaCl₂ and from aqueous solutions of either K₂HPO₄ or K₂CO₃. The phase composition of the powder synthesized from aqueous solutions of CaCl₂ and K₂HPO₄ included brushite (CaНРО₄·2H₂O). The phase composition of the powder synthesized from aqueous solutions of CaCl₂ and K₂CO₃ included calcite (CaCO₃). The phase composition of all synthesized powders contained potassium chloride (sylvine, KCl), as a reaction by-product. After heat treatment at 1000 °C of the powder containing low-crystalline hydroxyapatite and KCl, powder of chlorapatite (Са₁₀(РО₄)₆Cl₂) was obtained. After heat treatment of a powder containing brushite (CaНРО₄·2H₂O) and KCl at 800 and 1000 °C, a powder with the phase composition including β-calcium pyrophosphate (β-Ca₂P₂O₇), β-calcium orthophosphate (β-Ca₃(PO₄)₂), and potassium-calcium pyrophosphate (K₂CaP₂O₇) was obtained. Heat treatment of calcite (CaCO₃) powder at 800 °C, as expected, led to the formation of calcium oxide (CaO). Synthesized powders, including biocompatible minerals such as hydroxyapatite, chlorapatite, brushite, monetite, calcium pyrophosphate, calcium potassium pyrophosphate, tricalcium phosphate, and calcite, can be used for the creation of biocompatible inorganic materials or composite materials with a biocompatible polymer matrix. The potassium chloride present in the synthesized powders can act as one of the precursors of biocompatible minerals, such as chlorapatite or calcium potassium pyrophosphate, or it can be treated as a removable inorganic porogen. Full article

Glycine receptors (GlyRs) are essential for inhibitory neurotransmission in the central nervous system (CNS) and represent promising targets against neurological disorders. Several indole alkaloids from Gelsemium species have been shown to modulate GlyRs. Notably, the anxiolytic and analgesic properties of certain Gelsemium alkaloids appear to depend on GlyR modulation. However, prior studies have focused on only a few indole alkaloids, leaving the activity of other Gelsemium compound classes unexplored. This study employed an integrative in silico approach to investigate the interactions between GlyR α1 and α3 subtypes and 162 structurally diverse Gelsemium compounds. Physicochemical, pharmacokinetic, and toxicological analyses identified compounds with favorable bioavailability in the CNS. Molecular docking revealed that indolic alkaloids bind the GlyR orthosteric site with profiles comparable to the reference Gelsemium compound, gelsemine. Molecular dynamics simulations confirmed the stability and conformational integrity of selected ligand-receptor complexes. Overall, novel potential GlyR modulators were identified, with several compounds showing a promising selectivity profile towards GlyR α1 and α3 subtypes. These findings further support the therapeutic potential of Gelsemium alkaloids and provide a foundation for further pharmacological and toxicological validation. Full article

An analysis was conducted to investigate how reaction system turbulence affects the butadiene-isoprene copolymerization in the presence of the TiCl₄ + Al(i-Bu)₃ catalytic system. A model was developed, which integrates CFD simulations of TiCl₄ + Al(i-Bu)₃ particle breakage based on population balance equations with the kinetic modeling of the butadiene-isoprene copolymerization. It was established that an increase in turbulent kinetic energy leads to a reduction in catalyst particle size, an increase in active site concentration, an acceleration of the copolymerization process, and a decrease in the average molecular weights of the copolymer. Furthermore, catalytic activity correlates with both the average and maximum values of turbulent kinetic energy in the reaction system, whereas the effect of the average residence time of catalytic particles under turbulent conditions is insignificant. Based on these results, recommendations were provided for optimizing the impact of reaction system turbulence on TiCl₄ + Al(i-Bu)₃ particles to enhance the butadiene-isoprene copolymerization rate and achieve precise control over the molecular weight characteristics of the copolymer. The findings of this study can be applied to optimize the synthesis technology of the cis-1,4 butadiene-isoprene copolymer, which is used in the production of frost-resistant rubber. Full article

Hancornia speciosa Gomes (H. speciosa) is present in several regions of Brazil. It is a plant traditionally used in the treatment of various diseases. This study aims to provide a comprehensive overview of scientific publications and patents related to H. speciosa, emphasizing its primary applications and potential utility. For scientific prospection, an extensive search for relevant publications was carried out in the Scopus database. For technological prospection, the Instituto Nacional de Propriedade Intelectual (INPI) and World Intellectual Property Organization (WIPO) databases were utilized. Research on H. speciosa spans across multiple domains, including agronomy, gastronomy, technology, and pharmaceuticals, revealing the identification of numerous pharmacologically interesting compounds, such as rutin, chlorogenic acid, bornesitol, and various triterpenes, such as Lupeol, α- and β-amyrin, and their respective acetates. Regarding patents, there is a notable emphasis on gastronomic applications, with only a limited number of patents dedicated to technological and health-related areas. The increasing interest in H. speciosa is evident from the various studies investigating the biological properties of its compounds, such as anti-inflammatory, antihypertensive, and antidiabetic actions. Additionally, there is significant potential for further exploration and advancement of research in the pharmaceutical and technological sectors. Full article

The present work is aimed at shedding light on the evolution of surface chemistry of a commercial activated carbon (AC) support during the preparation of supported metal oxide (MO) catalysts by the conventional wet impregnation method. Particular attention is paid to the chemical changes of oxygen-containing surface functionalities across three preparation stages of impregnation, oven-drying, and thermal treatment. AC was impregnated with aqueous solutions of several MO precursors (Al(NO₃)₃, Fe(NO₃)₃, Zn(NO₃)₂, SnCl₂, and Na₂WO₄) at 80 °C for 5 h, oven-dried at 120 °C for 24 h, and heat-treated at 200 °C and 850 °C for 2 h under an inert atmosphere. The surface chemistry of the resulting catalyst samples, classified in three series by the thermal treatment, was mainly studied by FT-IR spectroscopy, complemented by elemental analysis and pH of the point of zero charge (pH_pzc) measurements. During impregnation, phenolic hydroxyl and carboxylic acid groups were predominantly formed by wet oxidation of chromene, 2-pyrone, and ether-type structures found in the pristine AC. The extent of these oxidations correlated with the oxidising power of the precursor solutions. As expected, thermal treatment at 850 °C brought about markedly stronger chemical changes, with most of the above oxygen functionalities decomposing and forming less acidic structures, such as 4-pyrone groups, metal carboxylates, and C-O-M atomic groupings. All these surface chemical modifications result in a lowering of the strong basicity of the raw carbon support (pH_pzc ≈ 10.5), thus leading to pH_pzc values for the catalysts widely ranging from 1.6 to 9.7. Full article

Neurodegenerative diseases, including Alzheimer’s disease (AD), represent one of the main global health challenges. Cannabis sativa synthesizes spermidine-type alkaloids, whose potential biological activities have been little studied. This study aimed to isolate bioactive alkaloids from an alkaloid-enriched extract (AEE) of C. sativa roots throughout a bioguided approach using conventional chromatographic techniques based on AChE and BuChE inhibitory activities. A qualitative and semiquantitative analysis by UPLC-ESI-MS/MS as well as molecular modeling simulations were performed. In addition, predictive in silico analyses were conducted to assess toxicity properties. The alkaloids cannabisativine (CS) and anhydrocannabisativine (ACS) were isolated, and showed highly selective BuChE inhibitory activity. The molecular modeling study revealed a conserved interaction profile across both alkaloids, indicating the amino acids TRP82, GLU197, TYR440, and HIS438 as the major contributors involved in the complex formation. Finally, CS and ACS exhibited low in silico predictive toxicity values. In conclusion, CS and ACS alkaloids emerge as new selective BuChE inhibitors with therapeutic potential that deserves the attention from the field of pharmacology in neurodegenerative disease research. Additionally, this approach promotes innovation and environmental sustainability through the use of C. sativa roots. Full article

Covalent organic framework (COF) membranes are eminent candidates in filtration and separation applications due to their high porosity, ordered pore size, versatile molecular structure, inherent mechanical properties, and excellent stability. However, large-scale COF membranes suffer from several issues, including stacking and crystal defects, which negatively impact their rejection performance. In this study, a continuous thin film of porphyrinic-based COF (i.e., COF-TCPP (Fe)) with various thicknesses was fabricated on a PVDF support layer via a vacuum-assisted interfacial polymerization method. The composite membranes were then characterized, and their filtration and dye/salt separation performance were evaluated using a dead-end filtration cell. The results showed that the rejection efficiencies of Congo red and acid fuchsin for the optimal proposed membrane were 99.5% and 95.8%, respectively. In comparison, the corresponding values for the pristine membrane were 73.3% and 62.8%. The results also showed that with an increase in the COF loading concentration during synthesis, the membrane flux decreased, while the rejection efficiency increased. This study proposes a simple and effective method to mitigate the large-scale issues of COF-based membranes and to enhance the separation performance of existing polymeric membranes. Full article

Heyang Fragrance, a traditional incense dating back to the Eastern Han Dynasty (25–220 AD), was recently inscribed on China’s national list of intangible cultural heritage. This study aimed to systematically analyze three variants of Heyang Fragrance (Aicao, Qinqiang, and Jianjia) through integrated methodologies including electronic nose analysis, headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS), and antimicrobial activity assays. We selected Escherichia coli, Bacillus subtilis, and Candida glabrata for the antimicrobial activity assays. Comparative analysis revealed significant compositional differences between pre- and post-combustion volatile profiles. Upon ignition, sensor response values increased by 50–100% relative to baseline measurements, with sulfides, terpenes, and short-chain alkanes emerging as dominant components. Qinqiang demonstrated the highest odor activity values (OAVs), particularly through carvacrol (OAV = 6676.60) and eugenol (OAV = 2720.84), which collectively contributed to its complex aromatic characteristics. Antimicrobial assessments revealed concentration-dependent efficacy, with Qinqiang exhibiting broad antimicrobial activity against Escherichia coli (11.33 mm inhibition zone) and Bacillus subtilis (15.00 mm), while Jianjia showed maximal effectiveness against Bacillus subtilis (17.67 mm). These findings underscore the dual significance of Heyang Fragrance in cultural conservation and its prospective applications in aroma therapeutic and antimicrobial contexts. Full article

The advancement of catalytic materials is critical to improving the performance, reducing the cost and enhancing the sustainability of Proton Exchange Membrane (PEM) fuel cells and electrolyzers. Although Platinum Group Metal (PGM)-based electrocatalysts exhibit high electrochemical activity, their limited availability and the environmentally intensive extraction pose significant challenges. This study aims to demonstrate the direct reuse of recycled impure platinum (Pt) precursors for the synthesis of effective Pt/C electrocatalysts as a viable step toward circular hydrogen economy implementation. A low-cost and eco-friendly chlorine-based hydrometallurgical method was successfully employed to recycle over 99% of Pt from End-of-Life (EoL) Membrane Electrode Assemblies (MEAs), with an industrial perspective. Recycled metal precursor was used without purification to synthesize Pt/C electrocatalyst via a scalable and sustainable method. The catalyst was structurally and chemically characterized, and their electrochemical performance towards the Oxygen Reduction Reaction (ORR) was conducted under conditions simulating real operating environments. The recycled-metal-derived catalyst demonstrated comparable activity toward ORR (170 A/gPt) relative to a commercial catalyst, indicating its potential as viable alternative to conventional PGM-based catalysts. By integrating energy-efficient recycling with advanced material design, this work supports the development of cost-effective and green solutions for clean energy technologies aligned with a circular hydrogen economy model. Full article

Amomyrtus luma (A. luma), a native Chilean tree species, produces fruits containing 1–3 non-edible seeds, which are typically discarded as waste during processing. This study evaluated the fatty acid composition and bioactive properties of A. luma seed oil obtained through maceration, ultrasound extraction, and Soxhlet extraction, using hexane as the extraction solvent. Fatty acid methyl esters (FAMEs) were quantified using gas chromatography-flame ionization detection (GC–FID), revealing that linoleic acid was the most abundant (79.79–80.09%), followed by oleic acid (8.89–9.18%) and palmitic acid (7.29–7.40%), with no significant differences (p < 0.05) among extraction methods. However, extraction conditions significantly influenced the concentration of bioactive compounds, including total phenolics, flavonoids, tannins, lycopene, carotenoids, and antioxidant capacity, as determined through DPPH and FRAP assays. A strong correlation was observed between polyphenol content and antioxidant activity, particularly in maceration and ultrasound extraction, whereas Soxhlet extraction favored tocopherols and carotenoids due to the thermal degradation of polyphenols. Soxhlet extraction yielded the highest oil recovery, while ultrasound extraction preserved the highest levels of bioactive compounds and antioxidant capacity. No antimicrobial activity was detected against Staphylococcus aureus and Escherichia coli. These findings underscore the key role of extraction methods in determining the nutritional and functional quality of A. luma seed oil. Given its high unsaturated fatty acid content and bioactive potential, A. luma seed oil represents a promising ingredient for cosmetic and pharmaceutical applications, while contributing to waste valorization and sustainable resource utilization. Full article

Neglected diseases significantly impact the world, and there is a lack of effective treatments, requiring therapeutic alternatives. Thus, the study of the phytochemical and schistosomicidal activity evaluation of Copaifera oblongifolia leaves’ crude extract was conducted. The quercitrin (1) and afzelin (2) were isolated from the crude extract. In the in vitro schistosomicidal activity test, the isolated compounds demonstrated promising results, with 75% mortality at a concentration of 12.5 µM after 72 h. Molecular docking calculations indicated that compounds 1 and 2 could potentially interact with the amino acids of the FAD binding site in the TGR enzyme, a crucial enzyme for the survival of Schistosoma mansoni. These interactions could have binding energies comparable to praziquantel, a preferred drug for treating schistosomiasis. Therefore, in silico and in vitro investigations are crucial for developing new studies that can reveal the antiparasitic potential of compounds of plant origin. Full article

Edible mushrooms are well-known for their culinary and nutritional values. Additionally, they serve as a natural source of polyphenols, a group of bioactive compounds that significantly treat diseases associated with oxidative stress. The polyphenolic profile of mushrooms mainly consists of phenolic acids and flavonoids, whose chemical properties have attracted the attention of both the food and pharmaceutical industries. Consequently, methods for extracting polyphenols from mushrooms encompass conventional techniques (maceration and Soxhlet extraction) as well as innovative or green methods (ultrasound-assisted extraction, microwave-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, enzyme-assisted extraction, and pulsed electric field extraction). Nonetheless, extraction with pressurized liquids and supercritical fluids is considered the most suitable method, as they function in a gentle and selective manner, preserving the integrity of the phenolic compounds. The use of mushroom-derived phenolic compounds in food and pharmaceutical formulations continues to face challenges concerning the safety of these extracts, as they might contain unwanted substances. Future applications should incorporate purification systems to yield highly pure extracts, thereby creating safe polyphenol carriers (for food and pharmaceutical products) for consumers. Full article

An important property of arylboronic acids, particularly when considering their use in medicinal chemistry, is their pK_a in aqueous solution. The results of computational determination of absolute pK_as of arylboronic acids can be very disappointing in comparison to available experimental results, particularly in the case of large substituents. In this paper, the main origin of this problem is identified. It is shown that in order to obtain accurate pK_a values for arylboronic acids from computational quantum chemistry, it is necessary to consider the effect of different possible conformations of the hydroxyl groups in the acid and its conjugate base together with the low-energy conformations of their substituents. An improved practical procedure for the computational determination of the pK_as of arylboronic acids is proposed and applied to a set of recently synthesized arylboronic acids, yielding consistent results. Full article