Molecules

13 pages, 2774 KB

Open AccessArticle

Asymmetric Mannich Reaction of α-(2-Nitrophenylsulfenyl)imino Acetamide: A Cyclization-Driven Process

by Tsubasa Inokuma, Maki Miyamoto, Kazuki Okada, Genki Nagai and Ken-ichi Yamada

Molecules 2026, 31(3), 449; https://doi.org/10.3390/molecules31030449 - 27 Jan 2026

An enantioselective Mannich reaction of 2-(2-nitrophenylsulfenylimino)acetamide is described. Under the optimized conditions using proline, triethylamine, and diarylthiourea additives, the initially formed Mannich adduct undergoes irreversible cyclization to afford cyclic hemiaminal products in 21–58% yield, with diastereomeric ratios ranging from 53:47 to 83:17. Enantioselectivity [...] Read more.

An enantioselective Mannich reaction of 2-(2-nitrophenylsulfenylimino)acetamide is described. Under the optimized conditions using proline, triethylamine, and diarylthiourea additives, the initially formed Mannich adduct undergoes irreversible cyclization to afford cyclic hemiaminal products in 21–58% yield, with diastereomeric ratios ranging from 53:47 to 83:17. Enantioselectivity reaches up to 97% ee. The presence of N–H functionality of the substrate is crucial for this cyclization; in its absence, the Mannich adduct undergoes facile decomposition. Subsequent reduction in this intermediate efficiently furnished the corresponding homoserine derivative. Full article

(This article belongs to the Section Organic Chemistry)

► Show Figures

Figure 1

40 pages, 1108 KB

Open AccessReview

Advances in Catalysis Using N-Heterocyclic Carbene Platinum Complexes

by Anna Smoczyńska, Sylwia Ostrowska and Cezary Pietraszuk

Molecules 2026, 31(3), 448; https://doi.org/10.3390/molecules31030448 - 27 Jan 2026

Abstract

Apart from in hydrosilylation, platinum has traditionally played a limited role in homogeneous catalysis due to its high thermodynamic stability and lower intrinsic reactivity compared to other group 10 metals. However, the emergence of N-heterocyclic carbene (NHC) ligands has substantially broadened the catalytic [...] Read more.

Apart from in hydrosilylation, platinum has traditionally played a limited role in homogeneous catalysis due to its high thermodynamic stability and lower intrinsic reactivity compared to other group 10 metals. However, the emergence of N-heterocyclic carbene (NHC) ligands has substantially broadened the catalytic profile of transition metals by enabling access to new mechanistic pathways and enhancing robustness under demanding conditions. This review summarizes advances in Pt–NHC catalysis reported between 2010 and 2025. These transformations encompass hydrosilylation of amides and CO₂, hydroboration and diboration, hydroamination, alkyne hydration, hydrogenation, selective alkyne dimerization, Suzuki–Miyaura coupling, arene C–H borylation, and cycloisomerization reactions, in which NHC ligands enhance bond activation, control regio- and stereoselectivity, and stabilize reactive Pt intermediates, including chiral architectures, enabling high enantioselectivity. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules: Recent Advances in Organometallic Chemistry)

17 pages, 4297 KB

Open AccessArticle

Synthesis of Lignin-Derived Hierarchical Porous Carbon via Hydrothermal–Phosphoric Acid Synergistic Activation for Enhanced Adsorption of Tetracycline

by Xin Li, Yipeng Li, Yuhan Li, Mengyu Zhang and Jundong Zhu

Molecules 2026, 31(3), 447; https://doi.org/10.3390/molecules31030447 - 27 Jan 2026

Abstract

Tetracycline is a low-cost broad-spectrum antibiotic and widely used in medicine and aquaculture. Its residues are usually released into the environment through wastewater, which may lead to the spread of antibiotic resistance genes and pose ecological risks. To address this environmental issue, a [...] Read more.

Tetracycline is a low-cost broad-spectrum antibiotic and widely used in medicine and aquaculture. Its residues are usually released into the environment through wastewater, which may lead to the spread of antibiotic resistance genes and pose ecological risks. To address this environmental issue, a hierarchical lignin-derived porous carbon (LPHC) was synthesized using renewable biomass lignin as the precursor through a combined phosphoric acid-activated hydrothermal pretreatment. The resulting LPHC was used to effectively remove tetracycline from aqueous solutions. Characterization results indicated that LPHC had a high specific surface area (1157.25 m²·g⁻¹), a well-developed micro-mesoporous structure, and abundant surface oxygen-containing functional groups, which enhanced its interaction with target pollutants. Adsorption experiments showed that LPHC exhibited excellent adsorption performance for tetracycline, with a maximum adsorption capacity of 219.81 mg·g⁻¹. The adsorption process conformed to the Langmuir isotherm model, indicating that monolayer chemical adsorption was dominant. Mechanism analysis further confirmed that the adsorption process was controlled by multiple synergistic interactions, including pore filling, π-π electron donor–acceptor interactions, hydrogen bonding, and electrostatic attraction. This work proposes a feasible strategy to convert waste biomass into high-performance and environmentally friendly adsorbents, which provides technical feasibility for sustainable water purification technologies. Full article

(This article belongs to the Section Applied Chemistry)

► Show Figures

Figure 1

27 pages, 5905 KB

Open AccessArticle

Development of a Series of Tanshinone Derivatives Through Scaffold Hopping for Treating Non-Small-Cell Lung Cancer (NSCLC)

by Lan-Xin Zhou, Zheng-Yu Shu, Heng Li, Hui Zhong, Dou-Nan Xu, Lei Tang, Chu-Jiao Hu, Cheng Luo and Huan Xiong

Molecules 2026, 31(3), 446; https://doi.org/10.3390/molecules31030446 - 27 Jan 2026

Abstract

Non-small-cell lung cancer (NSCLC) is one of the most prevalent cancer types and accounts for the majority of cancer-related deaths worldwide. Tanshinone and its derivatives exhibit diverse biological activities, and their prominent antitumor potential has been well documented. In this study, we rationally [...] Read more.

Non-small-cell lung cancer (NSCLC) is one of the most prevalent cancer types and accounts for the majority of cancer-related deaths worldwide. Tanshinone and its derivatives exhibit diverse biological activities, and their prominent antitumor potential has been well documented. In this study, we rationally designed a series of tanshinone derivatives with a scaffold-hopping strategy. Thirty-five tanshinone derivatives were synthesized, and their cytotoxic activities against the NSCLC cell lines A549 and H838 were investigated. Concurrently, their safety profile was assessed in BEAS-2B cells. The results showed that compounds S2-1, S2-4, and S2-8 exhibited superior inhibitory activity against A549 cells compared with the positive control, β-lapachone. Meanwhile, compounds S2-1, S2-3, S2-4, S2-8, S2-13, and S2-14 exhibited similar or increased antiproliferation activity against H838 cells. Compounds S2-4 (0.58 ± 0.07 μM) and S2-8 (0.42 ± 0.04 μM) demonstrated the greatest potency towards H838 cells; compounds S2-13 (1.28 ± 0.13 μM) and S2-14 (1.80 ± 0.24 μM) exhibited potent and selective activity towards H838 cells. Molecular docking studies of S2-4/NLRP3 and S2-14/STAT3, combined with the structure–activity relationship (SAR) analysis, indicated that the benzofuran core containing an ortho-quinone, along with an amide linkage and a 1,2,3-triazole group introduced at the C-2 position of the furan ring, is an effective chemical scaffold for enhancing the anti-NSCLC activity of tanshinone derivatives. Full article

(This article belongs to the Special Issue Antitumor Bioactive Compounds: Synthesis, Extraction and Evaluation)

► Show Figures

Graphical abstract

20 pages, 1382 KB

Open AccessArticle

Leachability and Chemical Profiles of Per- and Polyfluoroalkyl Substances in Electronic Waste Components: Targeted and Non-Targeted Analysis

by Joshua O. Ocheje, Yelena Katsenovich, Berrin Tansel, Craig P. Dufresne and Natalia Quinete

Molecules 2026, 31(3), 445; https://doi.org/10.3390/molecules31030445 - 27 Jan 2026

Abstract

Electronic waste (e-waste) is a growing solid waste stream with largely undisclosed and poorly characterized fluorinated constituents. We evaluated per- and polyfluoroalkyl substances (PFAS) leachability from four e-waste components (phone screens, phone plastics, capacitors, and Lithium-ion batteries) using a 30-day deionized water leaching [...] Read more.

Electronic waste (e-waste) is a growing solid waste stream with largely undisclosed and poorly characterized fluorinated constituents. We evaluated per- and polyfluoroalkyl substances (PFAS) leachability from four e-waste components (phone screens, phone plastics, capacitors, and Lithium-ion batteries) using a 30-day deionized water leaching test. PFAS were extracted by solid-phase extraction using weak anion exchange (WAX) cartridges and analyzed with a liquid chromatography triple-quadrupole mass spectrometer. In addition, the PFAS chemical profiles of e-waste components were characterized by non-targeted analysis. Leachable sums of detected PFAS (∑PFAS) were highest in phone screens (1739–1932 ng·kg⁻¹) and phone plastics (1575–2197 ng·kg⁻¹) and an order of magnitude lower in Lithium-ion batteries (148–158 ng·kg⁻¹) and capacitors (147–243 ng·kg⁻¹). Short-chain perfluoroalkyl acids (PFAAs) (e.g., PFBA, PFHxA) and legacy acids (e.g., PFOA, PFNA) were more prevalent in phone screens/plastics, whereas capacitors and batteries showed mixed sulfonate/carboxylate patterns (PFOS, PFHxS, and 6:2 FTS). Although capacitors and Lithium-ion batteries contained essential PFAS with high hazard potential at trace levels, phone screens and phone plastics pose a greater risk per mass due to higher ∑PFAS levels and larger volumes. Non-targeted analysis using Orbitrap Astral revealed CF₂/CF₂O homologous trends (confidence levels 2–3) with corroborating targeted findings. These findings highlight the need for PFAS-free alternatives, the disclosure of fluorinated additives, and stronger end-of-life management strategies to prevent PFAS releases from e-waste. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Green Chemistry)

► Show Figures

Figure 1

19 pages, 1145 KB

Open AccessReview

Red Blood Cells in Normal and Pathological States: Redox Reactions of Hemoglobin

by Krzysztof Gwozdzinski, Anna Pieniazek and Lukasz Gwozdzinski

Molecules 2026, 31(3), 444; https://doi.org/10.3390/molecules31030444 - 27 Jan 2026

Abstract

Red blood cells (RBCs) play a key role in vascular origin pathologies such as nephropathy, retinopathy, and neuropathy. Altered RBCs also occur in the case of hereditary spherocytosis, hemoglobinopathies, sickle cell disease, thalassemia and hemolytic anemia. The consequence of damage to the cell [...] Read more.

Red blood cells (RBCs) play a key role in vascular origin pathologies such as nephropathy, retinopathy, and neuropathy. Altered RBCs also occur in the case of hereditary spherocytosis, hemoglobinopathies, sickle cell disease, thalassemia and hemolytic anemia. The consequence of damage to the cell membrane and cytoskeleton are changes in RBC deformability, which play an important role in microcirculation. In turn, oxidative changes in hemoglobin lead to impaired oxygen transport to cells and tissues and, consequently, to ischemia and hypoxia. In this review, we discuss the structure of normal and pathological RBCs, including, more broadly, red blood cells occurring in type 2 diabetes. We present factors that play a major role in RBC damage in this pathology. Finally, we characterize the participation of hemoglobin and heme in the induction of oxidative damage to biological material, including RBCs. Full article

(This article belongs to the Special Issue Advances in European Medicinal Chemistry)

► Show Figures

Figure 1

31 pages, 9124 KB

Open AccessFeature PaperArticle

Active Polysaccharide Films Incorporating Cannabis sativa Flower Extract for Extending the Shelf Life of Freeze-Dried Berries

by Renata Dobrucka, Elżbieta Studzińska-Sroka, Magdalena Paczkowska-Walendowska, Judyta Cielecka-Piontek, Małgorzata Gumienna, Małgorzata Lasik-Kurdyś and Marcin Szymański

Molecules 2026, 31(3), 443; https://doi.org/10.3390/molecules31030443 - 27 Jan 2026

Abstract

In this study, films based on polysaccharides with C. sativa flower extract were prepared for selected freeze-dried fruits: raspberry (Rubus idaeus L.) and blueberry (Vaccinium corymbosum L.). The extract used affected the barrier and mechanical properties of the film. The elongation [...] Read more.

In this study, films based on polysaccharides with C. sativa flower extract were prepared for selected freeze-dried fruits: raspberry (Rubus idaeus L.) and blueberry (Vaccinium corymbosum L.). The extract used affected the barrier and mechanical properties of the film. The elongation values of the film ranged from 32.5 ± 8.6 [%] (for sample 0) to 44.8 ± 8.2 [%] (for sample 4.0 F). The addition of the extract resulted in an increase in polyphenol content, proportional to the quantity of extract used. Spearman’s rank correlation analysis showed particularly strong correlations between colour indices (L*, a*, b*) and parameters describing antioxidant activity. The use of C. sativa flower extract in the polysaccharide matrix reduced the degradation of bioactive compounds during the storage of packaged fruit. In all cases of stored raspberries, a decrease in the number of moulds and yeasts was observed after 2 and 8 weeks. The greatest reduction in moulds and yeasts was recorded for the 4.0 F film (from 0.86 to 0.64 log cfu/g). In the case of blueberries, the total number of bacteria before storage was 2.52 log cfu/g, while after 8 weeks of storage in 4.0 F, this number significantly decreased to 2.28 log cfu/g. As in the case of raspberries, a reduction in mould and yeast was observed, with concentrations falling from an initial value of 0.89 to 0.67 log cfu/g after 8 weeks of storage at 4.0 F. Full article

(This article belongs to the Special Issue Development of Active Bio-Packaging Films for Food Industry with Natural Bioactive Compounds)

► Show Figures

Figure 1

13 pages, 971 KB

Open AccessArticle

Impact of Thymidine Loop Modifications on Telomeric G-Quadruplex Catalytic Systems for Asymmetric Sulfoxidation

by Claudia Finamore, Carmen Festa, Daniela Benigno, Carla Aliberti, Rosa Barbato, Simona De Marino, Aldo Galeone, Veronica Esposito and Antonella Virgilio

Molecules 2026, 31(3), 442; https://doi.org/10.3390/molecules31030442 - 27 Jan 2026

Abstract

G-quadruplex (G4) DNA structures have recently emerged as promising chiral scaffolds for enantioselective catalysis. This study investigates how thymidine loop modifications influence the catalytic performance of the telomeric G4 sequence HT21 in the asymmetric sulfoxidation of thioanisole. To this end, several singly or [...] Read more.

G-quadruplex (G4) DNA structures have recently emerged as promising chiral scaffolds for enantioselective catalysis. This study investigates how thymidine loop modifications influence the catalytic performance of the telomeric G4 sequence HT21 in the asymmetric sulfoxidation of thioanisole. To this end, several singly or doubly modified HT21 derivatives were synthesized by using β-L-2′-deoxythymidine, 5-hydroxymethyl-2′-deoxyuridine, and 5-bromo-2′-deoxyuridine instead of a T residue, or β-L-2′-deoxyadonesine instead of an A residue, in specific positions within the TTA loops. The catalytic activity of these analogues was evaluated in the Cu(II)-mediated oxidation of thioanisole using hydrogen peroxide as oxidant. All modified sequences maintained complete substrate conversion, but their enantioselectivities varied markedly. Whereas the highest enantiomeric excess (84% ee) had previously been achieved with the HT21 analogue bearing a β-L-2′-deoxyadenosine in the first loop, the thymidine-based modifications, either alone or in combination, resulted in lower ee values, suggesting that loop alterations critically affect the chiral microenvironment, not all loop positions are functionally equivalent, and single substitutions within the same loop can result in different enantioselectivities. These findings highlight new insights on how individual loop residues contribute to asymmetric induction and offer further details for tuning G4-based catalytic scaffolds. Full article

15 pages, 2049 KB

Open AccessArticle

Rapid Authentication of Flowers of Panax ginseng and Panax notoginseng Using High-Resolution Melting (HRM) Analysis

by Menghu Wang, Wenpei Li, Yafeng Zuo, Qianqian Jiang, Jincai Li, Wenhai Zhang and Xiangsong Meng

Molecules 2026, 31(3), 441; https://doi.org/10.3390/molecules31030441 - 27 Jan 2026

Abstract

The flowers of Panax ginseng C. A. Mey. (PG) and Panax notoginseng (Burkill) F. H. Chen ex C. H. Chow (PN) are morphologically indistinguishable after drying, leading to prevalent adulteration that compromises product quality and consumer safety. To address this issue, we developed [...] Read more.

The flowers of Panax ginseng C. A. Mey. (PG) and Panax notoginseng (Burkill) F. H. Chen ex C. H. Chow (PN) are morphologically indistinguishable after drying, leading to prevalent adulteration that compromises product quality and consumer safety. To address this issue, we developed a rapid, closed-tube molecular authentication method based on high-resolution melting (HRM) analysis. Species-specific primer pairs were designed to target the conserved ITS and rbcL-accD regions, with PNG-2 selected as the optimal candidate owing to its stable genotyping performance and moderate GC content. Our results established GC content, rather than amplicon length, as the primary determinant of the melting temperature (Tm). Notably, the experimentally measured Tm values were consistently 0.7–1.5 °C higher than theoretical predictions, a discrepancy attributable to the stabilizing effect of the saturated fluorescent dye. To ensure maximum diagnostic reliability, the HRM results were cross-validated through a three-tier system comprising ITS2 phylogenetic analysis, agarose gel electrophoresis, and Sanger sequencing. The practical utility and matrix robustness of the assay were further verified using a diversified validation cohort of 30 commercial samples, including 24 floral batches and 6 root-derived products (root slices and ultramicro powders). The HRM profiles demonstrated 100% concordance with DNA barcoding results, effectively identifying mislabeled products across different botanical matrices and processing forms. This methodology, which can be completed within 3 h, provides a significantly more cost-effective and rapid alternative to traditional sequencing-based methods for large-scale market surveillance and industrial quality control. Full article

► Show Figures

Graphical abstract

18 pages, 19109 KB

Open AccessReview

Artificial Intelligence for Perovskite Additive Engineering: From Molecular Screening to Autonomous Discovery

by Xin-De Wang, Zhi-Rui Chen, Wen-Kao Li, Peng-Jie Guo, Cheng Mu, Ze-Feng Gao and Zhong-Yi Lu

Molecules 2026, 31(3), 440; https://doi.org/10.3390/molecules31030440 - 27 Jan 2026

Abstract

Additive engineering plays a crucial role in enhancing the performance of perovskite solar cells (PSCs), yet identifying suitable additives within the vast chemical space remains a significant challenge. This paper describes a paradigm shift in additive discovery from trial-and-error methods to AI-driven approaches. [...] Read more.

Additive engineering plays a crucial role in enhancing the performance of perovskite solar cells (PSCs), yet identifying suitable additives within the vast chemical space remains a significant challenge. This paper describes a paradigm shift in additive discovery from trial-and-error methods to AI-driven approaches. We first establish the physicochemical foundations of additive engineering and the descriptors commonly employed in machine learning algorithms. Next, we discuss intelligent process optimization, highlighting how active learning algorithms effectively tune complex precursor formulations with minimal experimental iterations. Additionally, we explore the role of AI in mechanism elucidation and the potential prospects of generative models in the field of additives. Finally, we emphasize the emerging trend of integrating large language models with autonomous laboratories for closed-loop autonomous discovery, offering a promising pathway to accelerate the commercialization of PSCs. Full article

(This article belongs to the Special Issue Featured Review Papers in Applied Chemistry)

► Show Figures

Figure 1

21 pages, 2972 KB

Open AccessArticle

Synthesis, Antimicrobial Activity and Cytotoxicity of Novel (Piperidin-4-yl)adamantane-1-carboxylate N-Substituted Derivatives

by Kaldybay D. Praliyev, Gulmira S. Akhmetova, Ulzhalgas B. Issayeva, Samir A. Ross, Manas T. Omyrzakov, Ilya S. Korotetskiy, Ardak B. Jumagaziyeva, Aigul E. Malmakova, Tulegen M. Seilkhanov, Ubaidilla M. Datkhayev, Lyudmila N. Ivanova, Zhanar A. Iskakbayeva, Olzhas T. Seilkhanov and Natalya V. Zubenko

Molecules 2026, 31(3), 439; https://doi.org/10.3390/molecules31030439 - 27 Jan 2026

Abstract

The cyclic adamantane framework possesses unique properties such as bulkiness, symmetry, and high lipophilicity. Research aimed at discovering new pharmaceutical agents within the adamantane series continues. In the present work, a targeted modification was carried out to combine two pharmacophore fragments—adamantane and piperidine—within [...] Read more.

The cyclic adamantane framework possesses unique properties such as bulkiness, symmetry, and high lipophilicity. Research aimed at discovering new pharmaceutical agents within the adamantane series continues. In the present work, a targeted modification was carried out to combine two pharmacophore fragments—adamantane and piperidine—within a single molecule. Based on a series of N-substituted piperidin-4-ones, the corresponding secondary alcohols were obtained by reduction with sodium borohydride in isopropanol and subsequent acylation of these alcohols with adamantane carbonyl chloride yielded the corresponding adamantane-carboxylate esters. The structure of the synthesized compounds was studied by NMR methods, including COSY (¹H-¹H), HMQC (¹H-¹³C) and HMBC (¹H-¹³C) techniques. The values of chemical shifts, multiplicities, and integrated intensities of ¹H and ¹³C signals in one-dimensional NMR spectra were determined. The results of COSY (¹H-¹H), HMQC (¹H-¹³C), and HMBC (¹H-¹³C) revealed homo- and heteronuclear interactions, confirming the structure of the studied compounds. The cytotoxic activities of the synthesized compounds were studied. It was found that the synthesized substituted piperidines bearing an adamantane fragment exhibit in vitro antimicrobial and antifungal activity against museum microbial strains (Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 6538-P, Candida albicans ATCC 10231, Cryptococcus neoformans) and demonstrate significant advantages over the reference drugs used in clinical practice, such as fluconazole and ampicillin. These compounds are therefore recommended for further in-depth studies. Full article

► Show Figures

Figure 1

19 pages, 2313 KB

Open AccessArticle

Development of a High-Throughput UHPLC-DMS-MS/MS Method for Targeted Quantitation of Pertinent Phospholipid Classes in Colon Cancer

by Miriam Wimmer, Olivia I. Coleman, Adam Sorbie, Dirk Haller, Veronika Somoza and Andreas Dunkel

Molecules 2026, 31(3), 438; https://doi.org/10.3390/molecules31030438 - 27 Jan 2026

Abstract

Phospholipids are essential membrane constituents that regulate diverse cellular processes, yet most current workflows rely on relative quantification using high-resolution LC–MS. We developed and validated a highly selective targeted method that couples liquid chromatography with differential mobility spectrometry and tandem mass spectrometry (LC–DMS–MS/MS), [...] Read more.

Phospholipids are essential membrane constituents that regulate diverse cellular processes, yet most current workflows rely on relative quantification using high-resolution LC–MS. We developed and validated a highly selective targeted method that couples liquid chromatography with differential mobility spectrometry and tandem mass spectrometry (LC–DMS–MS/MS), providing enhanced selectivity and reduced background noise. The assay quantifies 63 phospholipid species across four classes, achieving excellent recoveries and limits of quantification in the low ng per mg tissue range. Applied to tissues from a colon cancer study in mice, the method enabled the absolute quantification of 47 species, 22 of which were significantly increased in tumor tissue versus adjacent non-tumor tissue. While phosphatidylcholines were the most abundant class overall, the largest fold changes were observed in long-chain phosphatidylglycerol and phosphatidylethanolamine species. LC–DMS–MS/MS thus offers a robust, selective platform for absolute phospholipid quantification and for detecting disease-associated lipid remodeling. Full article

(This article belongs to the Section Analytical Chemistry)

► Show Figures

Figure 1

28 pages, 3392 KB

Open AccessArticle

Hydrothermal Conversion of Wastewater Treatment Sands into Dual-Phase FAU/LTA Zeolite: Structural Insights and Performance in Methylene Blue Adsorption

by Diana Guaya, María José Jara and José Luis Cortina

Molecules 2026, 31(3), 437; https://doi.org/10.3390/molecules31030437 - 27 Jan 2026

Abstract

This study presents a sustainable valorization strategy for wastewater treatment plant (WWTP) residual sands through their hydrothermal conversion into a dual-phase FAU/LTA zeolite and evaluates its adsorption performance toward methylene blue (MB) as a model cationic contaminant. The synthesized material (ZEO-RS) exhibited a [...] Read more.

This study presents a sustainable valorization strategy for wastewater treatment plant (WWTP) residual sands through their hydrothermal conversion into a dual-phase FAU/LTA zeolite and evaluates its adsorption performance toward methylene blue (MB) as a model cationic contaminant. The synthesized material (ZEO-RS) exhibited a low Si/Al ratio (~1.7), well-developed FAU supercages with minor LTA domains, and high structural integrity, as confirmed by XRD, FTIR, XRF, SEM and PZC analyses. ZEO-RS demonstrated rapid adsorption kinetics, reaching approximately 92% of equilibrium uptake within 30 min and following a pseudo-second-order kinetic model (k₂= 2.73 g·mg⁻¹·h⁻¹). Equilibrium data were best described by the Langmuir isotherm, yielding a maximum adsorption capacity of 34.2 mg·g⁻¹ at 20 °C, with favorable separation factors (0 < r_L < 1), while Freundlich fitting indicated moderate surface heterogeneity. Thermodynamic analysis revealed that MB adsorption is spontaneous (ΔG° = −11.98 to −12.56 kJ·mol⁻¹), mildly endothermic (ΔH° = +5.26 kJ·mol⁻¹), and entropy-driven (ΔS° = +0.059 kJ·mol⁻¹·K⁻¹). FTIR evidence, combined with pH-dependent behavior, indicates that adsorption proceeds via synergistic electrostatic attraction, pore confinement within FAU domains, and partial ion-exchange interactions. Desorption efficiencies conducted under mild acidic, neutral, and alkaline conditions resulted in low MB release (1–8%), indicating strong dye retention and high framework stability. Overall, the results demonstrate that WWTP residual sands are an effective and scalable low-cost precursor for producing zeolitic adsorbents, supporting their potential application in sustainable water purification and circular-economy-based wastewater treatment strategies. Full article

(This article belongs to the Special Issue Design, Synthesis, and Application of Zeolite Materials)

► Show Figures

Figure 1

21 pages, 1661 KB

Open AccessArticle

Impact of Selected Metal Oxides on the Thermodynamics of Solid Rocket Propellant Combustion

by Kinga Janowska, Sylwia Waśkiewicz, Paweł Skóra, Lukasz Hawelek, Piotr Prasuła, Tomasz Jarosz and Agnieszka Stolarczyk

Molecules 2026, 31(3), 436; https://doi.org/10.3390/molecules31030436 - 27 Jan 2026

Abstract

A series of catalytic oxides (Fe₂O₃, CuO, ZnO, and Cu₂O) were investigated as prospective additives shaping the thermal features of a model solid rocket propellant (SRP) formulation utilising ammonium nitrate as the oxidising agent. An extensive investigation [...] Read more.

A series of catalytic oxides (Fe₂O₃, CuO, ZnO, and Cu₂O) were investigated as prospective additives shaping the thermal features of a model solid rocket propellant (SRP) formulation utilising ammonium nitrate as the oxidising agent. An extensive investigation of the thermal behaviour (DSC and ignition/explosion temperature studies) of the model and catalyst-bearing SRP formulations was conducted, providing insights into both the thermodynamics and mechanism of combustion of these systems. XRD analysis of post-combustion residues was used to validate the mechanistic claims, as well as to provide information about the behaviour of copper oxides in the SRP system. In addition, the linear combustion velocity was experimentally determined, and the power output was estimated from density, linear combustion velocity and DSC data, in order to assess the potential motor performance of the tested formulations. The obtained results show that the utilisation of metal oxides significantly improves the combustion performance of ammonium nitrate-based SRP formulations relative to the unmodified ammonium nitrate-based propellants. Full article

(This article belongs to the Special Issue Advances in Energetic Materials and Associated Detection Methods)

► Show Figures

Graphical abstract

13 pages, 1063 KB

Open AccessArticle

Radiation-Induced Synthesis of a Minocycline-Derived Polycyclic Scaffold with Anti-Inflammatory and Antibacterial Effects

by Gyeong Han Jeong, Hanui Lee, Tae Hoon Kim, Byung Yeoup Chung, Seung Sik Lee and Hyoung-Woo Bai

Molecules 2026, 31(3), 435; https://doi.org/10.3390/molecules31030435 - 27 Jan 2026

Abstract

Radiation is widely used as a powerful tool for inducing molecular transformation and expanding chemical diversity; however, its application in clinically relevant antibiotics remains limited. Minocycline (1), a clinically used tetracycline antibiotic, was subjected to gamma irradiation at doses of up [...] Read more.

Radiation is widely used as a powerful tool for inducing molecular transformation and expanding chemical diversity; however, its application in clinically relevant antibiotics remains limited. Minocycline (1), a clinically used tetracycline antibiotic, was subjected to gamma irradiation at doses of up to 30 kGy, resulting in the formation of a previously unreported radiation-induced derivative, minocyclinosin A (2). The structure of the newly generated compound was elucidated by comprehensive spectroscopic analyses, including one- and two-dimensional nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry, which revealed extensive A-ring cleavage, degradation, and recyclization to form a unique cyclopenta[b]anthracene-type tetracycline scaffold. Biological evaluation revealed that minocyclinosin A exhibited enhanced anti-inflammatory activity by suppressing lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages, while maintaining antibacterial activity against skin inflammation-associated Staphylococcus species. High-performance liquid chromatography further demonstrated a clear dose-dependent molecular conversion, with irradiation at 30 kGy affording minocyclinosin A as the major product with a conversion efficiency of approximately 78.3%. Full article

(This article belongs to the Special Issue Design, Synthesis and Biological Evaluation of Medicinal Potential Compounds—2nd Edition)

► Show Figures

Figure 1

1 pages, 126 KB

Open AccessCorrection

Correction: Irfan et al. Recent Advances in MXene-Based Composites for Their Efficiency in the Degradation of Antibiotics and Water Splitting. Molecules 2025, 30, 3712

by Syed Irfan, Sadaf Bashir Khan, Sheikha Lardhi and S. AlFaify

Molecules 2026, 31(3), 434; https://doi.org/10.3390/molecules31030434 - 27 Jan 2026

Abstract

References [...] Full article

(This article belongs to the Section Photochemistry)

12 pages, 1258 KB

Open AccessArticle

Water Molecule(s) Inside the Selectivity Filter of Aquaporin 1: A DFT Study

by Silvia Angelova, Luis Manuel Frutos, Nikoleta Kircheva, Yulian Zagranyarski, Obis D. Castaño and Todor Dudev

Molecules 2026, 31(3), 433; https://doi.org/10.3390/molecules31030433 - 27 Jan 2026

Abstract

Aquaporin 1 (AQP1) is a transmembrane protein that acts as a highly selective channel for the rapid passage of water across cell membranes, driven by osmotic gradients. The narrowest part of the water channel pore—the selectivity filter (SF)—plays a key role in ensuring [...] Read more.

Aquaporin 1 (AQP1) is a transmembrane protein that acts as a highly selective channel for the rapid passage of water across cell membranes, driven by osmotic gradients. The narrowest part of the water channel pore—the selectivity filter (SF)—plays a key role in ensuring selective and efficient water transport. In this study, density functional theory (DFT) at the M062X/6-311+G(d,p) level was used to identify the preferred position of the water molecule(s) inside the SF and to elucidate the forces that lead to its displacement during permeation. A systematic scan along the pore axis identified a well-defined energy minimum where a single water molecule was optimally stabilized by hydrogen bonds with SF residues. A second water molecule was introduced to study how the incoming water affects the translocation of the first water molecule. The resulting energy and force profiles reveal that the approaching water molecule gradually pushes the bound water forward, ultimately occupying its favorable binding site. These results provide an atomistic description of the positioning and displacement of water molecules in SF and offer a quantitative view of the fundamental interactions that govern water transport in AQPs. Full article

(This article belongs to the Section Computational and Theoretical Chemistry)

► Show Figures

Figure 1

27 pages, 6194 KB

Open AccessReview

Biochar Innovations for Organic Pollutant Remediation in Contaminated Soils

by Pengfei Li, Ying Liu, Yangyang Sun and Congyu Zhang

Molecules 2026, 31(3), 432; https://doi.org/10.3390/molecules31030432 - 27 Jan 2026

Abstract

Soil contamination by organic pollutants such as polycyclic aromatic hydrocarbons (PAHs), pesticides, pharmaceuticals, and petroleum hydrocarbons has emerged as a global environmental concern due to their persistence, bioaccumulation, and potential health risks. Biochar, a carbon-rich material derived from the pyrolysis of biomass, has [...] Read more.

Soil contamination by organic pollutants such as polycyclic aromatic hydrocarbons (PAHs), pesticides, pharmaceuticals, and petroleum hydrocarbons has emerged as a global environmental concern due to their persistence, bioaccumulation, and potential health risks. Biochar, a carbon-rich material derived from the pyrolysis of biomass, has attracted increasing attention as an environmentally friendly and cost-effective amendment for remediating contaminated soils. This review systematically summarizes recent advances in the application of biochar for the remediation of organic pollutants in soils to guide the development of more effective biochar-based strategies for sustainable soil remediation. The physicochemical properties of biochar influencing pollutant interactions are discussed, including surface area, pore structure, functional groups, and aromaticity. Mechanisms such as adsorption, sequestration, microbial interaction enhancement, and catalytic degradation are elucidated. Moreover, this review highlights the influence of feedstock types, pyrolysis conditions, biochar modification strategies, and environmental factors on biochar performance. The analysis reveals that biochar performance is strongly dependent on feedstock selection, pyrolysis conditions, and post-modification strategies, which jointly determine pollutant immobilization efficiency and long-term stability. Current challenges, such as long-term stability, pollutant desorption, and ecological impacts, are critically examined. Finally, future perspectives on the design of engineered biochar and its integration with other remediation technologies are proposed. Rationally engineered biochar, particularly when integrated with biological or physicochemical remediation technologies, demonstrates strong potential for efficient and sustainable soil remediation. Full article

(This article belongs to the Special Issue Green Synthesis and Environmental Application of Biomass-Based Materials)

► Show Figures

Figure 1

15 pages, 3676 KB

Open AccessArticle

Emulsion Quality and Functional Properties of Natural Emulsion Systems with Xanthan Gum as a Stabilizer and Carrier of Compounds Based on Enzymatically Modified Mutton Tallow and Hemp Oil

by Małgorzata Kowalska, Magdalena Wozniak, Anna Zbikowska, Jerzy Szakiel and Paweł Turek

Molecules 2026, 31(3), 431; https://doi.org/10.3390/molecules31030431 - 26 Jan 2026

Abstract

The aging population and increasing prevalence of oxidative stress-related diseases underscore the need for functional food and pharmaceutical formulations enriched with bioactive compounds. This study aimed to design sustainable emulsion systems incorporating enzymatically modified fats with enhanced functional and bioactive properties. Enzymatic interesterification [...] Read more.

The aging population and increasing prevalence of oxidative stress-related diseases underscore the need for functional food and pharmaceutical formulations enriched with bioactive compounds. This study aimed to design sustainable emulsion systems incorporating enzymatically modified fats with enhanced functional and bioactive properties. Enzymatic interesterification was employed as an environmentally friendly alternative to chemical catalysis, enabling the transformation of natural lipids without generating undesirable trans isomers. The lipid phase was formulated from blends of hemp oil, a plant-derived source rich in polyunsaturated fatty acids with documented antioxidant potential, and mutton tallow, in an effort to valorize meat industry by-products. Systematic evaluation of emulsion stability, viscosity, and textural properties was conducted using Turbiscan analysis and texture profile analysis. The results demonstrated that xanthan gum concentration was the primary determinant of structural stability, physicochemical stability, and structural integrity of the emulsion systems. Formulation no. 38 (0.8% w/w xanthan gum) was identified as the statistically most stable system based on Turbiscan Stability Index values (TSI = 1.4). Although emulsions containing 1.0% w/w xanthan gum exhibited similarly low TSI values and slightly smaller final droplet diameters, formulation E38 showed the smallest increase in droplet size during storage (<1 µm), indicating superior resistance to structural changes over time. Fat composition showed minimal influence on emulsion behavior, suggesting that lipid selection should prioritize nutritional and bioactive value. These findings indicate that emulsions based on enzymatically modified fats and stabilized with natural polysaccharides can serve as physically stable systems with potential applicability in food, cosmeceutical, and pharmaceutical formulations intended for bioactive compound delivery. Full article

(This article belongs to the Section Food Chemistry)

► Show Figures

Figure 1

Journal Description

Molecules

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Topical Collections

Further Information

Guidelines

MDPI Initiatives

Follow MDPI