Crown Ether–Magnesium Ion Complexes: A Reliable Theoretical Estimation of Host–Guest Interaction and Binding Energies in a Solvent

Metal ion detection is of paramount importance for health monitoring. The host should properly accommodate the desired ion and be selective with respect to other potential guests, which makes devising ion sensors a demanding task. Recently (Phys. Chem. Chem. Phys. 2023, 25, 32656), we suggested a procedure for a computational design of crown ethers that can capture magnesium ions. In the present contribution we apply the same approach to search for Mg2+ trap with thiophene units, in accord with proposed hosts for Na+ and K+ ions (Adv. Funct. Mater. 2016, 26, 514). Additionally, we present a procedure based on the combination of Density Functional Theory based Molecular Dynamics and the Interacting Quantum Fragments methodology for determination of host–guest interaction and binding energies in a model with a large number of explicit solvent molecules. The presented strategy could be applied for identification of the right host for an arbitrary guest

Enhancing functional properties of fruit juices with highly active xylanase from Aspergillus tubingensis FAT35

BACKGROUND The growing consumer demand for functional fruit juices has emphasized the need for targeted enzyme applications in juice processing. Among these, xylanase has emerged as a critical enzyme for improving the extraction and quality of juices from xylan-rich fruits. However, despite its potential, xylanase remains insufficiently characterized for functional juice production, and further evaluation is necessary. RESULTS In the present study, a screening assay identified Aspergillus tubingensis FAT35 as the most efficient xylanase-producing isolate among a set of fungal strains. Solid-state fermentation using agro-industrial residues was optimized, resulting in high-yield enzyme production: 550 U mL−1, which corresponds to 2333 U g−1. The enzyme exhibited high xylanase activity with negligible pectinase and cellulase side activities. Application of the xylanase to orange and pineapple juices significantly improved juice yield (17% and 3%), sugar content (22% and 39%) and clarity (2% and 22%). Furthermore, treated juices showed enhanced antioxidant and antimicrobial activities. These functional improvements were attributed to the formation of the prebiotic oligosaccharide xylotetraose (X4), indicating added health value. CONCLUSION The optimized xylanase from A. tubingensis FAT35 demonstrates strong potential for use in the fruit juice industry. Its ability to enhance both technological parameters and bioactive properties of juices highlights its role in the development of functional beverages and underscores the importance of further testing and application of xylanases in food biotechnology. © 2025 Society of Chemical Industry

III International Conference on Noncovalent Interactions (ICNI-III)

This virtual collection of Reviews, Concepts and Research Articles in Chemistry Europe journals (Chem. Eur. J., Eur. J. Inorg. Chem., Eur. J. Org. Chem., ChemCatChem, ChemPlusChem and ChemPhysChem) highlights the latest developments in the field of weak interactions. The Collection includes contributions from participants of ICNI-III (17-21 June 2024, Belgrade, Serbia) and from other researchers in this exciting are of research

The Content of Flavanols in Wood Waste Extracts from Serbian Cooperage

The ageing of alcoholic beverages in contact with wood has a long tradition in Serbia. Oak is most commonly used in cooperage, but other types of wood such as black locust, cherry and mulberry are also used. The cooperage industry generates large quantities of wood by- products, which can be utilised as a valuable source of phenolic compounds with high antioxidant and antimicrobial activity. Among them, flavanols are of particular interest due to their protective role in wood and their potential applications in the food industry. Cherry wood is already known as a rich source of flavanols, including catechin, epicatechin, and procyanidins [1]. However, to our knowledge, limited data is available on the content of flavanols in other wood species used in cooperage. The aim of this study was to analyse the content of flavanols in wood waste extracts from different species used in Serbian cooperage. Identification and quantification were carried out using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). A total of six flavanols were detected, including catechin, (-)-epicatechin, (-)-epicatechin-gallate, (-)-catechin gallate, (-)-gallocatechin and (-)-epigallocatechin-gallate. Each species had a characteristic profile, with different dominant compounds observed. The richest sources of flavanols were black locust and Myrobalan plum, while the lowest content of flavanols was observed in oak samples. An exceptionally high content of (-)-epicatechin was found in black locust, (-)-catechin gallate in Myrobalan plum and catechin in wild cherry. White mulberry contained (-)-catechin gallate as the only compound, though in lower concentrations than Myrobalan plum. All oak samples contained (-)-epicatechin gallate as the dominant flavanol. These results highlight the species-specific flavanol profiles and suggest that wood by-products from cooperage could be further valorised as a natural source of bioactive compounds

Izolovanje i karakterizacija imunoglobulina G iz zečijeg seruma

Imunoglobulin G je glikoprotein molekulske mase od 150 kDa i predstavlja najzastupljeniju klasu antitela u krvi sisara i ima važnu funkciju u imunom odgovoru. Dosadašnja istraživanja su se intenzivno bavila optimizacijom metoda za izolovanje IgG, uključujući hromatografske tehnike poput hromatografije sa proteinom A i G, jonoizmenjivačke hromatografije i multimodalne hromatografije. Prema dosadašnjim studijama, razvoj brzih i visoko specifičnih metoda prečišćavanja omogućava efikasnije dobijanje IgG –a za dijagnostičke i terapijske primene. Ipak, izazovi i dalje postoje u pogledu očuvanja stabilnosti i funkcionalnosti molekula tokom procesa izolovanja. Cilj ovog rada bio je prečišćavanje antigen-specifičnog imunoglobulina G (IgG) iz seruma zečeva imunizovanih proteinom kikirikija, Ara h 2, jednim od glavnih alergena kikirikija. IgG je prečišćena primenom afinitetne hromatografije zasnovane na interakciji sa proteinom G, koji specifično vezuje Fc fragment imunoglobulina G. Prečišćeni IgG je analiziran elektroforetski (SDS-PAGE) radi provere čistoće i prisustva teških i lakih lanaca IgG-a, nakon čega je proverena i njihova specifičnost u imunološkim testovima poput Western blot-a i ELISA testa. Na osnovu dobijenih rezultata utvrđeno je da afinitetna hromatografija sa proteinom G pokazuje visoku efikasnost prilikom izolovanja antitela iz seruma zečeva. Provera specifičnosti, ELISAom i Western blot-om, ukazuje da izolovani IgG specifično prepoznaje alergen kikirikija Ara h 2

Biomarker composition and origin of Miocene pale lignites in China and Serbia | 中国−塞尔维亚中新世浅色褐煤生物标志化合物组成及其成因

Pale lignites are widely distributed in Cenozoic lignite basins around the world, but their origin is still controversial. Identifying their organic matter composition and formation mechanism is of great significance for reconstructing paleoclimate changes and clean and low-carbon utilization of lignite resources. Taking the Miocene pale lignite from Kolubara Basin in Serbia and Mile Basin in Yunnan, China as the research objects, organic geochemical methods, such as Soxhlet extraction, column chromatography separation and gas chromatography-mass spectrometry, were used to qualitatively and quantitatively analyze biomarker compounds in aliphatic and aromatic hydrocarbons to explore the differences in vegetation composition, microbial degradation and sedimentary environment during the coalification process of light and dark lignites. The results show that the pale lignite in Mile Basin has a high content of long-chain n-alkanes (up to 82.5%), showing a significant contribution from leaf waxes of terrestrial higher plants (mainly angiosperms), accompanied by a lower aquatic plant indicator value (Paq of 0.16) and a higher plant leaf wax index (Pwax of 0.86), indicating that its coal-forming environment was relatively dry and accompanied by strong microbial degradation; while the dark lignite has an increased proportion of medium-chain and short-chain n-alkanes, indicating that the input of aquatic plants and lower organisms was enhanced during the sedimentation process in Mile Basin. Both the pale and dark lignite in Kolubara are mainly contributed by gymnosperms. Content of diterpenoids in their aliphatic hydrocarbons is extremely high (87.3% for pale and 82.5% for dark), and the relative mass fraction ratio of diterpenoids to diterpenoids + triterpenoids is close to 1, reflecting the predominance of conifers in the peatland. At the same time, the higher relative mass fraction ratio of C31(R)hopane to total hopane and C30 hop-17(21)-ene to C30αβhopane reveal that Kolubara lignites were formed under relatively oxidative, acidic and low thermal evolution conditions. In addition, perylene and higher CWDI values indicate that pale lignite in two basins was subjected to stronger degradation, which is consistent with the higher content of hopane. By comparing the differences between Cenozoic pale and dark lignite, it is clarified that the sedimentary environment is the main controlling color change of lignite

Liquid chromatography in determination of pharmacokinetic properties of compounds in drug discovery process

Liquid chromatography plays a pivotal role in the determination of pharmacokinetic properties during drug discovery, particularly through the evaluation of lipophilicity. This parameter is essential in drug development, significantly influencing pharmacokinetic and pharmacodynamic behavior of potential drugs. It affects membrane permeability, solubility, distribution, and interaction with biological targets, making it a central focus in the early stages of drug design. Poor lipophilicity-related characteristics are often associated with drug failures, inefficacy, toxicity, and increased development costs. Experimental and computational methods, such as chromatographic techniques and theoretical calculations, are vital for accurately determining lipophilicity. These approaches enable the simulation of biological processes, providing insights into how lipophilicity impacts ADME (absorption, distribution, metabolism, and excretion) properties and supporting the optimization of drug candidates. In silico tools further enhance the efficiency of ADME evaluations, reducing the risk of pharmacokinetic-related failures and streamlining the drug discovery process

Fast and selective protein modification with iron-substituted polyoxometalates via a radical pathway

Oxidative modifications of proteins are crucial post-translational modifications that profoundly impact their structure, function, and turnover. Developing chemical methods that selectively induce oxidative protein modifications and cleavage would significantly facilitate elucidation of these oxidative processes, benefiting our understanding of disease mechanisms, identifying novel therapeutic targets, and advancing biotechnological applications. In this work, we demonstrate that all-inorganic discrete polyoxometalate (POM) clusters stabilize redox active metal centers such as Fe(III) and Mn(III) under physiological pH and temperature (pH = 7.5, 37 °C), enabling the generation of reactive oxygen species (ROS) under mild aqueous conditions. Specifically, we show that catalytic amounts of the iron-substituted POM K7[FeIII(α2-P2W17O61)(H2O)] (FeIIIWD), in the presence of ascorbate (Asc), rapidly induce selective oxidation and cleavage of hen egg-white lysozyme (HEWL) in four narrow regions of the protein sequence. The protein cleavage sites are all located near the interaction sites of MIIIWD (M = Mn or Fe) catalysts with the protein surface. In contrast, the manganese-substituted POM K7[MnIII(α2-P2W17O61)(H2O)] (MnIIIWD) shows no similar catalytic activity, pointing towards a different radical mechanism. These findings highlight the potential of well-tailored inorganic clusters to facilitate selective catalytic processes, enabling iron to target specific regions of a protein sequence without relying on coordination sites on the protein surface, while offering flexibility in reaction conditions

Liquid chromatography in determination of pharmacokinetic properties of compounds in drug discovery process

Liquid chromatography plays a pivotal role in the determination of pharmacokinetic properties during drug discovery, particularly through the evaluation of lipophilicity. This parameter is essential in drug development, significantly influencing pharmacokinetic and pharmacodynamic behavior of potential drugs. It affects membrane permeability, solubility, distribution, and interaction with biological targets, making it a central focus in the early stages of drug design. Poor lipophilicity-related characteristics are often associated with drug failures, inefficacy, toxicity, and increased development costs. Experimental and computational methods, such as chromatographic techniques and theoretical calculations, are vital for accurately determining lipophilicity. These approaches enable the simulation of biological processes, providing insights into how lipophilicity impacts ADME (absorption, distribution, metabolism, and excretion) properties and supporting the optimization of drug candidates. In silico tools further enhance the efficiency of ADME evaluations, reducing the risk of pharmacokineticrelated failures and streamlining the drug discovery process