AppliedChem, Volume 5, Issue 4 (December 2025) – 9 articles

The presence of 2-methylisoborneol (2-MIB) in water is a critical global concern due to its low threshold and resistance to conventional processes. In the present study, activated carbon/alginate (AC/alginate) composite beads were synthesized via ionic gelation method for the removal of 2-MIB from aqueous solution. The physicochemical characteristics of the adsorbent were determined using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques. The effects of contact time, solution pH, initial 2-MIB concentration and adsorbent dose on adsorption were examined. Over 95% of 2-MIB removal was obtained under optimum conditions within 360 min. The adsorption equilibrium was well described by Langmuir (R² = 0.97) and Freundlich (R² = 0.96) models suggesting that 2-MIB adsorption involves both monolayer and multilayer adsorption. Kinetic modeling revealed that the pseudo-first order model showed strong fits to the experimental data, indicating the role of surface adsorption in controlling the rate of adsorption. The adsorbent demonstrated reasonable stability, retaining 59% removal efficiency after four adsorption–desorption cycles, highlighting its potential for repeated application in water treatment. Overall, the AC/alginate composite beads were found to be promising for the effective elimination of 2-MIB from water. Full article

In today’s chemistry, greener and more energy-efficient ways of making new materials are becoming increasingly important. In this work, two types of (3-aminopropyl) triethoxysilane-grafted silica were synthesized using a one-pot method with two different porogens: Pluronic P123 and cetyltrimethylammonium bromide, and then modified with silver nanoparticles. Both syntheses produced amorphous silica with crystalline silver. EDX and EDX elemental mapping confirmed that the modification with silver nanoparticles was successful, and an even distribution of silver on the silica surface with an average silver load of around 16% was determined. After silver nanoparticle modification, silica synthesized using cetyltrimethylammonium bromide as a porogen was mesoporous, whereas silica synthesis using Pluronic P123 as a porogen yielded a nonporous product. The synthesized silicas exhibited surface areas of 345 ± 2 and 8.80 ± 0.05 m²/g for samples prepared using cetyltrimethylammonium bromide and Pluronic P123 as porogens, respectively, and both silicas were stable below 250 °C. Full article

Type 2 diabetes mellitus (T2DM) is a growing global health challenge, expected to affect over 600 million people by 2045. The discovery of new antidiabetic agents remains resource-intensive, motivating the use of machine learning (ML) for virtual screening based on molecular structure. In this study, we developed a predictive pipeline integrating two distinct descriptor types: high-dimensional numerical features from the Mordred library (>1800 2D/3D descriptors) and categorical ontological annotations from the ClassyFire and ChEBI systems. These encode hierarchical chemical classifications and functional group labels. The dataset included 45 active compounds and thousands of inactive molecules, depending on the descriptor system. To address class imbalance, we applied SMOTE and created balanced training and test sets while preserving independent validation sets. Thirteen ML models—including regression, SVM, naive Bayes, decision trees, ensemble methods, and others—were trained using stratified 12-fold cross-validation and evaluated across training, test, and validation. Ridge Regression showed the best generalization (MCC = 0.814), with Gradient Boosting following (MCC = 0.570). Feature importance analysis highlighted the complementary nature of the descriptors: Ridge Regression emphasized ClassyFire taxonomies such as CHEMONTID:0000229 and CHEBI:35622, while Mordred-based models (e.g., Random Forest) prioritized structural and electronic features like MAXsssCH and ETA_dEpsilon_D. This study is the first to systematically integrate and compare structural and ontological descriptors for antidiabetic compound prediction. The framework offers a scalable and interpretable approach to virtual screening and can be extended to other therapeutic domains to accelerate early-stage drug discovery. Full article

“Lumblija” is a Croatian autochthonous sweet bread which recently obtained a European Protected Geographical Indication (PGI) label. The peculiarity of “Lumblija” is the use of ingredients such as concentrated grape must, rose or herbal brandy, and various herbs and spices, mostly produced and collected in the area of the island of Korčula. To the author’s knowledge, the volatile compounds of “Lumblija” have not been investigated till now. The aim of this study was to characterise the volatile compounds responsible for the distinctive aroma of the traditional sweet bread “Lumblija”, which is widely appreciated for its unique sensory properties. Four samples of “Lumblija” were investigated. Headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry analysis (HS-SPME/GC-MS) was applied for volatile compound characterisation of “Lumblija” samples. A total of 50 volatile compounds were identified in the “Lumblija” samples. Volatile compounds belong to different chemical classes: terpenes, phenylpropanoids, alcohols, aldehydes, esters, ketones, aromatic hydrocarbons, and carboxylic acids. Among them, terpenes and phenylpropanoids were the most numerous and the most abundant volatile compounds. Most differences in the volatile compound profile of “Lumblija” samples can be attributed to some specific ingredients such as spices. The results of this study could be useful to establish a volatile compound profile of “Lumblija”, which could serve as an indicator of the authenticity and quality of this autochthonous bakery product. Full article

Electrospun fibers serve as a medium for the targeted release of active compounds, facilitating the desired therapeutic effects in drug administration. The point of this study was to find the best conditions for making electrospun fibers from cellulose acetate (CA) and poly(ε-caprolactone) (PCL), mixed with pure oxyresveratrol extract from Artrocarpus lakoocha Roxberg (Moraceae). Additionally, the study focused on evaluating the antioxidant properties, antityrosinase activity, and freeze–thaw stability of the resulting fibers. We incorporated a concentration of oxyresveratrol at 0.1% w/w into various mass ratios of CA/PCL blended fiber sheets (1:0, 3:1, 1:1, 1:3), utilizing mixed solvents of acetone/DMF (2:1% v/v) and chloroform/DMF (9:1% v/v) for preparation. The fiber sheets displayed a continuous and uniform structure, with fiber diameters ranging from 300 to 1000 nanometers. We investigated the release kinetics of oxyresveratrol from the fibrous substrates using the total immersion technique, specifically in phosphate-buffered saline at a pH of 7.4. The results showed that the fiber sheet with a 3:1 w/w ratio of CA to PCL and a 0.1 w/w loading of oxyresveratrol showed the most significant release of oxyresveratrol at the 2 h mark, and it continued to release consistently at this peak value for up to 24 h. The antioxidant and anti-tyrosinase properties of oxyresveratrol in fiber sheets were more stable than those of free oxyresveratrol at the same concentrations. The fiber sheet presents a promising avenue for a user-friendly transdermal patch application. Full article

This study examined the impact of five grapevine rootstocks (R110, 140Ru, 3309C, 41B, and FERCAL) on must composition, nitrogen status, and sensory attributes of Vitis vinifera L. cv. Assyrtiko wines. Vines were grown under uniform vineyard conditions, and microvinifications were conducted consistently across treatments. Rootstock genotype significantly influenced Baumé, density, titratable acidity, pH, and yeast-assimilable nitrogen (YAN). Musts from R110 contained the highest YAN (226.80 ± 0.99 mg/L) and intermediate Baumé (12.5°), whereas 140Ru exhibited the lowest YAN (132.60 ± 0.46 mg/L) and Baumé (11.7°). Wines from R110 contained the highest tannin concentration (0.375 g/L), while FERCAL produced the highest ethanol content (13.1% vol). Sensory evaluation revealed significant rootstock effects on color intensity, aroma intensity, aroma complexity, balance, and overall quality, with R110 and 3309C receiving the highest scores. The findings demonstrate that rootstock selection may affect the chemical and sensory profile of Assyrtiko wines, providing a practical tool for optimizing wine style and quality across diverse viticultural environments. Further research is needed to confirm these findings and explore extra parameters and novel rootstock–scion interactions. Full article

The genetic material in living systems is mainly stored in DNA molecules, which in turn play a dominant biological role in relation to the coding and transfer of genetic information, the biosynthesis of proteins and RNA and the packaging and regulation of DNA expression and accessibility. These features, strictly dictated by the three-dimensional structure of DNA, are governed by non-covalent chemical interactions that drive the folding process of these biological macromolecules. The Main Mechanical Forces (MMFs) approach is a recently formulated calculation method, based on the accurate prediction of structural features of biomolecules through an in-depth assessment of the interplay between specific non-covalent chemical interactions and related mechanical forces developed during the folding process. By adopting the MMFs method in the context of nucleic acids, we report here the results obtained in terms of predicting three-dimensional DNA oligomer tertiary structures. To this end, we have developed tailored nucleic acid-specific equations, enabling to predict the torsion angles (with a relevant level of agreement with experimental values) of the phosphate-sugar backbone of the three model molecules A-, B- and Z- DNA used in this study. To increase the validity of this methodology, we have conducted RMSD measurements, indicating that there is a weak but rather acceptable match between the calculated vs. predicted A-DNA structure, whereas the prediction of the BII-DNA and Z-DNA tertiary structures was fully correct. Full article

Hydrogen-bond-like M···H–C interactions in square-planar d⁸ metal complexes have recently gained attention as structure-directing elements and design motifs in asymmetric catalysis. In this study, we explore these weak interactions not as static features, but as key modulators of molecular motion. We synthesized four cis-[N,N′-pentamethylenebis(iminomethylazolato)]M(II) (M = Pt, Pd), including iminomethyl-2-imidazole, iminomethyl-5-imidazole, and iminomethylpyrrolato Pt(II) complexes and an iminomethylpyrrolato Pd(II) analog. All complexes display reversible flipping of the alkylene bridge across the coordination plane, with the M···H–C interaction alternately engaging from above or below. This dynamic motion was characterized by variable-temperature ¹H NMR spectroscopy, revealing activation parameters for the flipping process. X-ray crystallography confirmed geometries consistent with hydrogen-bond-like interactions, while NBO analysis based on DFT calculations provided insight into their electronic nature. Interestingly, although Pt and Pd display comparable M···H–C distances, solvent effects dominate the flipping kinetics over metal identity. These findings highlight the role of hydrogen-bond-like M···H–C interactions not only in structural stabilization, but also in regulating conformational dynamics. Full article

Water contamination by heavy metals, particularly lead, derived from industrialization, climate change, and urbanization, represents a critical risk to human health and the environment. Several agricultural biomass residues have demonstrated efficacy as contaminant adsorbents. In this context, the study aimed to evaluate the potential of sugarcane tip (ST) waste biomass treated by hydrothermal carbonization (HTC) to produce hydrochar as an adsorbent material for Pb²⁺ in aqueous solutions. Samples were synthesized from the waste biomass at temperatures of 180 °C, 215 °C, and 250 °C, with a constant pressure of 6 MPa. Aqueous solutions of Pb²⁺ were prepared at concentrations of 10, 25, 50, 75, and 100 mg/L. Each solution was stirred at 1 g of hydrochar at 150 rpm, 25 °C, and pH 5 for 15 to 120 min. The solutions were filtered and stored at 4 °C for flame atomic absorption spectrophotometry analysis. In all cases, equilibrium was reached rapidly—within 15 min or less—as indicated by the stabilization of q_t values over time. At an initial concentration of 100 mg L⁻¹, the highest equilibrium uptake was observed for the hydrochar synthesized at ST HTC 180 °C (4.90 mg g⁻¹), followed by 4.58 mg g⁻¹ and 4.52 mg g⁻¹ for ST HTC 215 °C and ST HTC 250 °C, respectively. For the ST HTC 180 °C, the Sips model provided the best correlation with the experimental data, exhibiting a high maximum capacity (q_max = 240.8 mg g⁻¹; K_s = 0.007; n = 1.09; R² = 0.975), which reinforces the heterogeneous nature of the material’s surface. Hydrothermal synthesis increased the amount of acidic active sites in the ST HTC 180 °C material from 1.3950 to 3.8543 meq g⁻¹, which may influence the electrical charge of the Pb²⁺ adsorption process. HTC-treated sugarcane tip biomass represents a promising alternative for the synthesis of adsorbent materials, contributing to water remediation and promoting the circular economy by sustainably utilizing agricultural waste. Full article