Molecules

18 pages, 2788 KiB

Open AccessArticle

Efficient Removal of Ciprofloxacin from Water Using High-Surface-Area Activated Carbon Derived from Rice Husks: Adsorption Isotherms, Kinetics, and Thermodynamic Evaluation

by Esra Demirdağ, Mehmet Ferit Demirel, Veysel Benek, Elif Doğru, Yunus Önal, Mehmet Hüseyin Alkan, Kadir Erol and İhsan Alacabey

Molecules 2025, 30(12), 2501; https://doi.org/10.3390/molecules30122501 (registering DOI) - 7 Jun 2025

Abstract

Activated carbon is widely recognized as an effective material for removing pollutants, especially pharmaceutical residues, from water. In this study, high-surface-area activated carbon derived from rice husks (RHAC) was synthesized via KOH activation and used for the adsorption of ciprofloxacin, a widely used [...] Read more.

Activated carbon is widely recognized as an effective material for removing pollutants, especially pharmaceutical residues, from water. In this study, high-surface-area activated carbon derived from rice husks (RHAC) was synthesized via KOH activation and used for the adsorption of ciprofloxacin, a widely used fluoroquinolone antibiotic. Its adsorption behavior was systematically investigated through batch experiments varying the pH, adsorbent dosage, contact time, initial concentration, and temperature. The RHAC exhibited a high surface area of 1539.7 m²/g and achieved a maximum adsorption capacity of 398.4 mg·g⁻¹. The Freundlich isotherm best describes its adsorption equilibrium, suggesting multilayer adsorption on a heterogeneous surface. Kinetic modeling revealed that the adsorption process followed a pseudo second-order model (R² = 0.9981), indicating chemisorption as the rate-limiting mechanism. Thermodynamic parameters (ΔH° = 6.61 kJ/mol, ΔG° < 0) confirmed that the process was endothermic and spontaneous. These findings demonstrate that RHAC is a highly efficient, low-cost, and sustainable adsorbent for removing ciprofloxacin from aqueous environments. Full article

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22 pages, 8453 KiB

Open AccessArticle

Harnessing BiOI/V₂O₅ Nanocomposites: Advanced Bifunctional Catalysts for Visible-Light Driven Environmental Remediation and Antibacterial Activity

by Anil Pandey, Narayan Gyawali, Devendra Shrestha, Insup Lee, Santu Shrestha, Subas Acharya, Pujan Nepal, Binod Gaire, Vince Fualo, Sabita Devi Sharma and Jae Ryang Hahn

Molecules 2025, 30(12), 2500; https://doi.org/10.3390/molecules30122500 - 6 Jun 2025

Abstract

Efficient photocatalysts based on composite materials are essential for addressing environmental pollution and enhancing water purification. This study presents a novel BiOI/V₂O₅ nanocomposite (BVNC) with a flower-like layered structure, synthesized via a low-temperature solvothermal process followed by high-pressure annealing for [...] Read more.

Efficient photocatalysts based on composite materials are essential for addressing environmental pollution and enhancing water purification. This study presents a novel BiOI/V₂O₅ nanocomposite (BVNC) with a flower-like layered structure, synthesized via a low-temperature solvothermal process followed by high-pressure annealing for visible light (VL)-driven dye degradation and antibacterial activities. Compared to individual BiOI nanoparticles (BOINP) and V₂O₅ nanoparticles (VONP), under VL, the BVNC demonstrated significantly enhanced photocatalytic and antibacterial activity. The best-performing BVNC achieved a remarkable methylene blue degradation efficiency of 95.7% within 140 min, with a rate constant value 439% and 430% of those of BOINP and VONP, respectively. Additionally, BVNC exhibited high photocatalytic efficiencies for rhodamine 6G (94.0%), methyl orange (90.4%), and bisphenol A (69.5%) over 160 min, highlighting the superior performance of the composite materials for cationic and anionic dyes. Furthermore, BVNC established outstanding antibacterial capability against Staphylococcus aureus and Escherichia coli, demonstrating zones of inhibition of 12.24 and 11.62 mm, respectively. The improved catalytic and antibacterial capability is ascribed to the presence of a robust p-n heterojunction between BOINP and VONP, which broadens the photo-absorption range, reduces bandgap energy, and facilitates the significant separation of excitons and faster release of reactive oxygen species. Full article

(This article belongs to the Special Issue Advances in Composite Photocatalysts)

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37 pages, 1205 KiB

Open AccessReview

Phenolic Azobenzene as Ligand for Cation Complexation—Syntheses and Applications

by Jan Hočevar, Jernej Iskra and Estelle Leonard

Molecules 2025, 30(12), 2499; https://doi.org/10.3390/molecules30122499 - 6 Jun 2025

Abstract

Phenolic azobenzenes have garnered significant attention as functional materials due to their ability to undergo reversible photoisomerization and their potential for cation complexation. This review aims to provide a comprehensive overview of the recent developments in the synthesis, properties, and applications of phenolic [...] Read more.

Phenolic azobenzenes have garnered significant attention as functional materials due to their ability to undergo reversible photoisomerization and their potential for cation complexation. This review aims to provide a comprehensive overview of the recent developments in the synthesis, properties, and applications of phenolic azobenzene derivatives in cation binding and complexation. This article explores various synthetic strategies for the preparation of phenolic azobenzenes. Additionally, the mechanisms of cation complexation, including the role of the phenolic hydroxyl group and the azobenzene scaffold, are discussed, along with insights into the coordination chemistry involved. This review further examines the diverse applications of phenolic azobenzene complexes in fields such as ion sensing, catalysis, and biological and DSSC applications. Full article

(This article belongs to the Special Issue Advances in Phenolic Based Complexes)

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32 pages, 4898 KiB

Open AccessReview

A Review of Natural and Synthetic Chalcones as Anticancer Agents Targeting Topoisomerase Enzymes

by François-Xavier Toublet, Aurélie Laurent and Christelle Pouget

Molecules 2025, 30(12), 2498; https://doi.org/10.3390/molecules30122498 - 6 Jun 2025

Abstract

Cancer remains one of the leading causes of morbidity and mortality worldwide, driving the search for innovative and selective therapeutic agents. Topoisomerases I and II are essential enzymes involved in key cellular processes such as DNA replication and transcription. They have emerged as [...] Read more.

Cancer remains one of the leading causes of morbidity and mortality worldwide, driving the search for innovative and selective therapeutic agents. Topoisomerases I and II are essential enzymes involved in key cellular processes such as DNA replication and transcription. They have emerged as valuable anticancer targets; thus, many inhibitors of topoisomerases have been designed and some of them are considered to be major anticancer agents such as anthracyclines, etoposide or irinotecan. A great deal of attention is currently being paid to chalcones, a class of naturally occurring compounds, since they exhibit a wide range of biological activities, including anticancer properties. These compounds are characterized by an open-chain structure and an α,β-unsaturated carbonyl moiety that enables interaction with cellular targets. Recent studies aiming to design anti-topoisomerase agents have identified both natural and synthetic chalcones, including chalcone-based hybrids. This review highlights the structural diversity of chalcones as topoisomerase inhibitors and particular attention is given to structure–activity relationship studies and molecular hybridization strategies aimed at optimizing the pharmacological profile of chalcones. These findings underline the potential of chalcones as promising scaffolds in the design of next-generation anticancer agents. Full article

(This article belongs to the Special Issue Synthesis and Evaluation of Bioactivity of Enzyme Inhibitors)

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11 pages, 475 KiB

Open AccessArticle

Rapid Enantiomeric Ratio Determination of Multiple Amino Acids Using Ion Mobility-Mass Spectrometry

by Wenqing Xu, Estelle Rathahao-Paris and Sandra Alves

Molecules 2025, 30(12), 2497; https://doi.org/10.3390/molecules30122497 - 6 Jun 2025

Abstract

Chiral analysis is becoming increasingly important across various scientific fields, including chemistry, pharmaceuticals, biosciences, and more recently, metabolomics. In this context, a high-resolution and high-throughput method was developed for the simultaneous determination of the enantiomeric ratio (er) of seven pairs of [...] Read more.

Chiral analysis is becoming increasingly important across various scientific fields, including chemistry, pharmaceuticals, biosciences, and more recently, metabolomics. In this context, a high-resolution and high-throughput method was developed for the simultaneous determination of the enantiomeric ratio (er) of seven pairs of amino acid (AA) enantiomers (Arg, Gln, His, Met, Pro, Tyr, and Trp) using flow injection analysis coupled with ion mobility-mass spectrometry (FIA-IM-MS) technology. Specifically, the Single Ion Mobility Monitoring (SIM²) mode on a TIMS-Tof^TM instrument enabled the rapid relative quantification of chiral compound mixtures. A linear model accurately described the relationship between enantiomeric ratio and IM-MS response for Arg, Gln, and Pro enantiomers, as evidenced by high R² values and unbiased residuals. In contrast, non-linear trends were observed for His, Tyr, and Trp, where a quadratic model significantly improved the fit. However, the linear model was retained for Met, despite an R² of about 0.98, due to its comparable performance and simplicity. Measurement accuracy was confirmed with very good recovery rates for er values of 0.95 and 0.99 across all AAs. Finally, the potential of the FIA-SIM²-MS approach in chiral analysis was demonstrated, particularly its ability to provide a reliable and efficient high-throughput tool for accurate er determination. Full article

(This article belongs to the Special Issue Enantioselective Synthesis, Enantiomeric Separations and Chiral Recognition: 3rd Edition)

16 pages, 1065 KiB

Open AccessArticle

New Conjugatable Platinum(II) Chlorins: Synthesis, Reactivity and Singlet Oxygen Generation

by José Almeida, Giampaolo Barone, Luís Cunha-Silva, Ana F. R. Cerqueira, Augusto C. Tomé, Maria Rangel and Ana M. G. Silva

Molecules 2025, 30(12), 2496; https://doi.org/10.3390/molecules30122496 - 6 Jun 2025

Abstract

An efficient protocol was developed for the microwave-mediated metallation of 5-(4-methoxycarbonylphenyl)-10,15,20-tris(pentafluorophenyl)porphyrin (P1) with bis(benzonitrile)platinum dichloride salt and subsequent 1,3-dipolar cycloaddition of the resulting PtP1 with an azomethine ylide to give two isomeric metallochlorins: PtC1 (main isomer) and PtC3. The methyl [...] Read more.

An efficient protocol was developed for the microwave-mediated metallation of 5-(4-methoxycarbonylphenyl)-10,15,20-tris(pentafluorophenyl)porphyrin (P1) with bis(benzonitrile)platinum dichloride salt and subsequent 1,3-dipolar cycloaddition of the resulting PtP1 with an azomethine ylide to give two isomeric metallochlorins: PtC1 (main isomer) and PtC3. The methyl ester group of metalloporphyrin PtP1 and metallochlorin PtC1 was successfully hydrolysed in an alkaline medium to yield the corresponding derivatives PtP2 and PtC2 in moderate-to-good yields. As a proof of concept of the reactivity of the carboxy group in PtP2 and PtC2, these compounds were conjugated with a hydroxylated derivative of indomethacin, a known potent non-steroidal anti-inflammatory, obtaining the conjugates PtP2-Ind and PtC2-Ind. The obtained platinum(II) porphyrins and chlorins were characterized by UV-Vis, NMR spectroscopy and mass spectrometry. The structure of PtP1 was also confirmed by X-ray crystallography. Singlet oxygen generation studies were carried out, as well as theoretical calculations, which demonstrated that the prepared Pt(II) complexes can be considered potential photosensitizers for PDT. Full article

(This article belongs to the Section Colorants)

20 pages, 4029 KiB

Open AccessArticle

Dynamic Migration Characteristics of Potassium During Agricultural Waste Combustion and the Mechanism of Combined Chlorine–Sulfur Action

by Jian Li, Yunlong Zhou, Guochao Zhao and Qixin Yuan

Molecules 2025, 30(12), 2495; https://doi.org/10.3390/molecules30122495 - 6 Jun 2025

Abstract

Alkali metals in fuel seriously affect the normal operation of generator sets. Using agricultural waste (AW) from a corn field as raw material, the dynamic change of alkali metal K migration and transformation and the effect of competition between chlorine and sulfur on [...] Read more.

Alkali metals in fuel seriously affect the normal operation of generator sets. Using agricultural waste (AW) from a corn field as raw material, the dynamic change of alkali metal K migration and transformation and the effect of competition between chlorine and sulfur on the behavior of AW were studied systematically. The results showed that transformation between different forms of K, especially water-soluble K, occurred. At low temperatures, K remained in the ash in the form of inorganic salt, and high temperature precipitated K and formed insoluble alkali metal compounds. Via FactSage thermodynamic equilibrium calculations, it was confirmed that KCl reacted with SiO₂ to form a K₂O·nSiO₂ molten mixture in combustion. K initially existed in the form of KCl (s) and K₂SO₄ (s), high temperature promoted its transformation and decomposition, and it was eventually released as KCl (g). During combustion, Cl was more volatile than K, while S reduced the release of K and Cl through sulfation reaction to reduce the sediment viscosity. Full article

(This article belongs to the Special Issue Renewable Energy, Fuels and Chemicals from Biomass, 2nd Edition)

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11 pages, 1040 KiB

Open AccessArticle

A Concise Asymmetric Synthesis of Sex Pheromone of Euproctis pseudoconspersa (Strand) and Its Enantiomer

by Biyu An, Shengli Liu, Jianan Wang, Dan Liu, Qinghua Bian and Jiangchun Zhong

Molecules 2025, 30(12), 2494; https://doi.org/10.3390/molecules30122494 - 6 Jun 2025

Abstract

The tea tussock moth, Euproctis pseudoconspersa (Strand), is a serious pest, and its sex pheromone is (R)-10,14-dimethylpentadecyl isobutyrate. A new and concise asymmetric synthesis of the sex pheromone and its enantiomer was accomplished. The chiral methyl of the pheromone was introduced [...] Read more.

The tea tussock moth, Euproctis pseudoconspersa (Strand), is a serious pest, and its sex pheromone is (R)-10,14-dimethylpentadecyl isobutyrate. A new and concise asymmetric synthesis of the sex pheromone and its enantiomer was accomplished. The chiral methyl of the pheromone was introduced by Evans’s template, while the extension of the carbon chain was achieved through Li₂CuCl₄-catalyzed coupling of chiral tosylate with Grignard reagent. Full article

(This article belongs to the Special Issue Synthesis of Bioactive Compounds, 3rd Edition)

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17 pages, 2074 KiB

Open AccessArticle

The Synthesis of Polycarboxylate Dispersants Containing Benzenesulfonic Acid Groups and Their Performance in Promoting Coal Particle Dispersion

by Lin Li, Zhisen Li, Shuo Yang, Chuandong Ma, Wenqi Zhang, Meng He and Xiaofang You

Molecules 2025, 30(12), 2493; https://doi.org/10.3390/molecules30122493 - 6 Jun 2025

Abstract

In this study, a polycarboxylate coal–water slurry dispersant (SSPA) containing benzenesulfonic acid groups was synthesized using allyl alcohol polyoxyethylene ether 500, sodium styrenesulfonate, and acrylic acid as raw materials. The effects of SSPA and a commercially available naphthalene-based dispersant (MF) on the slurry [...] Read more.

In this study, a polycarboxylate coal–water slurry dispersant (SSPA) containing benzenesulfonic acid groups was synthesized using allyl alcohol polyoxyethylene ether 500, sodium styrenesulfonate, and acrylic acid as raw materials. The effects of SSPA and a commercially available naphthalene-based dispersant (MF) on the slurry characteristics of low-rank coal were compared, and the maximum solid content of CWS prepared with SSPA reached 65.2%, which was 4% higher than that achieved with MF (61.2%). Unlike the more electronegative MF dispersant, SSPA features long polyether side chains that exert a robust steric hindrance effect, significantly enhancing coal particle dispersion. This results in a decrease in apparent viscosity and an increase in the stability of the CWS formulated with SSPA. Furthermore, adsorption experiments revealed that the adsorption kinetics of both SSPA and MF on coal conformed to the pseudo-second-order kinetic model. SSPA’s adsorption on coal particles followed the Langmuir isothermal adsorption model, and the K_L value of 0.0094 for SSPA was greater than that of MF (0.0086). This indicates that SSPA has a stronger affinity for the coal surface. Overall, the superior adsorption efficacy of SSPA is attributed to the benzene ring in its nonpolar group, which facilitates steric hindrance with aromatic structures in coal. Additionally, SSPA improves slurry stability, achieving a penetration rate of 96.7%. Finally, the carboxylic acid groups in SSPA likely engage in electrostatic attraction with cations on the coal surface, enhancing adsorption. Full article

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17 pages, 3135 KiB

Open AccessArticle

Amide-Based Anti-Wear/Extreme-Pressure Additives for Silica-Thickened Greases: Structure and Wear Resistance

by Jolanta Drabik, Kamil Korasiak, Justyna Chrobak, Rafał Kozdrach, Julia Woch, Michał Cyl, Magdalena Zarębska, Bernadetta Kaźmierczak, Jolanta Iłowska and Katarzyna Szymańska

Molecules 2025, 30(12), 2492; https://doi.org/10.3390/molecules30122492 - 6 Jun 2025

Abstract

The lubricating properties of three secondary amides were evaluated using the four-ball apparatus method. It was found that the studied amides—N-propylpropanamide (AC3C3), N-propyloctanamide (AC3C8), and N-propyldodecanamide (AC3C12)—could be a promising group of new AW/EP (anti-wear/extreme-pressure) additives for lubricants, especially for silica-thickened greases. Of [...] Read more.

The lubricating properties of three secondary amides were evaluated using the four-ball apparatus method. It was found that the studied amides—N-propylpropanamide (AC3C3), N-propyloctanamide (AC3C8), and N-propyldodecanamide (AC3C12)—could be a promising group of new AW/EP (anti-wear/extreme-pressure) additives for lubricants, especially for silica-thickened greases. Of the amides tested, AC3C8 was found to have the best properties. The synthesized amide structures were immobilized on SBA-15 nanosilica and examined as described above. Notably, SBA-15 has not previously been reported as a potential lubricant additive. The results of the tribological tests showed that SBA-15-immobilized amides performed better than non-immobilized amides. Nevertheless, the lack of stability of the amide-grafted SBA-15 when dispersed in oil limits its use in targeted formulations and should be improved through further research. By testing a silica-thickened grease, a synergistic effect was observed between the free-amide AC3C8 and a commercially available additive containing butylated triphenyl phosphate. A 240% increase in the Goz40 parameter (anti-wear properties) and a 150% increase in welding load (extreme-pressure properties) were obtained with the addition of 2%w/w of commercial additive and 3%w/w of AC3C8 to a base oil. Full article

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

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12 pages, 2327 KiB

Open AccessArticle

Measuring the Carboxypeptidase and γ-Glutamyltranspeptidase Activities of Lager and Ale Yeasts to Assess Their Impact on the Release of Odorant Polyfunctional Thiols Through Fermentation

by Coraline Calicis, Romain Christiaens, Natacha Loquet, Margaux Simon and Sonia Collin

Molecules 2025, 30(12), 2491; https://doi.org/10.3390/molecules30122491 - 6 Jun 2025

Abstract

Two enzymatic assays, based on release of p-nitroaniline and its spectrophotometric detection at 405 nm, were used to screen lager and ale brewing yeasts for carboxypeptidase and γ-glutamyltranspeptidase activity. Both activities were found in all the investigated yeasts and did not significantly [...] Read more.

Two enzymatic assays, based on release of p-nitroaniline and its spectrophotometric detection at 405 nm, were used to screen lager and ale brewing yeasts for carboxypeptidase and γ-glutamyltranspeptidase activity. Both activities were found in all the investigated yeasts and did not significantly distinguish Saccharomyces cerevisiae from S. pastorianus species. Large between-strain differences were measured for both carboxypeptidase (from 1.61 A/h for BRAS-45 to 41.71 A/h for E-30) and γ-glutamyltranspeptidase (from 1.26 A/h for US-05 to 48.72 A/h for S-33). No correlation was found between either enzymatic activity and the previously published ability of Saccharomyces yeasts to degrade glutathionyl or γ-GluCys- precursors to free polyfunctional thiols. Only for fermentation at lower temperatures does carboxypeptidase activity seem relevant for identifying the most interesting candidates. Measuring transport efficiency and β-lyase activities individually on the three possible intermediates emerges here as more promising for future flavor potential screening. Full article

(This article belongs to the Section Flavours and Fragrances)

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14 pages, 4691 KiB

Open AccessArticle

Conjugated Polymer Nanoparticles and Thin Films of Defect-Free Cyclic P3HT: Effects of Polymer Topology on the Nanostructure

by Tomohisa Watanabe, Masatoshi Maeki, Manabu Tokeshi, Tianle Gao, Feng Li, Takuya Isono, Kenji Tajima, Toshifumi Satoh, Shin-ichiro Sato and Takuya Yamamoto

Molecules 2025, 30(12), 2490; https://doi.org/10.3390/molecules30122490 - 6 Jun 2025

Abstract

Conjugated polymer nanoparticles (CP NPs) attract attention as nanoscale materials used for a variety of applications. In relation to this, the internal structure of CP NPs is an important factor for their properties, and numerous investigations have been carried out to control their [...] Read more.

Conjugated polymer nanoparticles (CP NPs) attract attention as nanoscale materials used for a variety of applications. In relation to this, the internal structure of CP NPs is an important factor for their properties, and numerous investigations have been carried out to control their nanomorphology. Here, we report the formation of CP NPs from defect-free cyclic poly(3-hexylthiophene) (c-P3HT) using a microfluidic device, and the effect of polymer topology on their structural and solvatochromic properties was investigated. CP NPs from c-P3HT exhibited reduced particle sizes and hypsochromic shifts in the absorption spectrum when compared to CP NPs obtained from corresponding linear P3HT (l-P3HT). Furthermore, steady responses in the solvatochromism of CP NPs from c-P3HT were observed, while those from l-P3HT displayed molecular weight dependency. These topology effects were caused by the change in the conjugation length, solubility, and crystallinity upon cyclization. Grazing incidence X-ray scattering (GIXS) studies of spin-coated P3HT films further showed a reduced interchain order and a larger proportion of face-on molecular orientation on a substrate for c-P3HTs. The various distinct structures observed for c-P3HT indicate the use of polymer topology as a means of nanostructure regulation. Full article

(This article belongs to the Section Macromolecular Chemistry)

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9 pages, 770 KiB

Open AccessCommunication

Chemical Constituents of Oxytropis ochrocephala

by Guoli Li, Zhengyu Liu, Jiacheng Xie, Yunao Jin, Lei Wang, Hongying Yang, Yilin He and Tong Shen

Molecules 2025, 30(12), 2489; https://doi.org/10.3390/molecules30122489 - 6 Jun 2025

Abstract

A new lignan (1) and a new phenolic glycoside (2), together with eighteen known compounds (3–20), were isolated from Oxytropis ochrocephala. Their structures were unambiguously elucidated by spectroscopic techniques (UV, IR, 1D and 2D [...] Read more.

A new lignan (1) and a new phenolic glycoside (2), together with eighteen known compounds (3–20), were isolated from Oxytropis ochrocephala. Their structures were unambiguously elucidated by spectroscopic techniques (UV, IR, 1D and 2D NMR), and HR-ESI-MS analysis, as well as by comparison with the literature. The insecticidal activity of these compounds was evaluated against Tetranychus urticae Koch, and the results showed that compounds 3, 9, 15, and 16 had a weak inhibitory effect at a concentration of 1 mg/mL after treatment for 24 h. Full article

(This article belongs to the Section Natural Products Chemistry)

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29 pages, 891 KiB

Open AccessReview

Phytosterols: Extraction Methods, Analytical Techniques, and Biological Activity

by Byoung-Hoon Yoon, Van-Long Truong and Woo-Sik Jeong

Molecules 2025, 30(12), 2488; https://doi.org/10.3390/molecules30122488 - 6 Jun 2025

Abstract

Phytosterols, essential components of plant cell membranes, are abundant in fruits, vegetables, nuts, and seeds. Among them, β-sitosterol, campesterol, and stigmasterol have drawn significant interest for their well-documented biological activities. This review highlights recent advancements in extraction and analytical methods aimed at improving [...] Read more.

Phytosterols, essential components of plant cell membranes, are abundant in fruits, vegetables, nuts, and seeds. Among them, β-sitosterol, campesterol, and stigmasterol have drawn significant interest for their well-documented biological activities. This review highlights recent advancements in extraction and analytical methods aimed at improving phytosterol yield, maintaining chemical stability, and reducing environmental impact. These innovative, eco-friendly techniques offer promising alternatives to traditional extraction approaches and hold potential for industrial-scale use. Phytosterols possess various bioactive properties, including antioxidant, anti-inflammatory, chemopreventive, cholesterol-lowering, and neuroprotective effects. Through these mechanisms, dietary phytosterols may help prevent cardiovascular and neurodegenerative diseases, type 2 diabetes, and certain cancers. Recent studies have focused on the identification, isolation, purification, and characterization of phytosterols from diverse food matrices, along with assessing their health benefits. However, the specific molecular pathways responsible for their pharmacological actions remain poorly understood, highlighting the need for further research, particularly in human clinical trials. This review provides a comprehensive overview of the extraction strategies, biological functions, and mechanisms of action of phytosterols, offering valuable insights for developing phytosterol-enriched functional foods and nutraceuticals. Full article

(This article belongs to the Special Issue Extraction and Analysis of Natural Products in Food—2nd Edition)

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22 pages, 3948 KiB

Open AccessArticle

Self-Standing Carbon Fiber Electrodes Doped with Pd Nanoparticles as Electrocatalysts in Zinc–Air Batteries

by Cristian Daniel Jaimes-Paez, Miguel García-Rollán, Francisco José García-Mateos, Ramiro Ruiz-Rosas, Juana M. Rosas, José Rodríguez-Mirasol, Tomás Cordero, Emilia Morallón and Diego Cazorla-Amorós

Molecules 2025, 30(12), 2487; https://doi.org/10.3390/molecules30122487 - 6 Jun 2025

Abstract

In this work, the effect of the palladium precursor on the Oxygen Reduction Reaction (ORR) performance of lignin-based electrospun carbon fibers was studied. The fibers were spun from a lignin-ethanol solution free of any binder, where different Pd salts were added at two [...] Read more.

In this work, the effect of the palladium precursor on the Oxygen Reduction Reaction (ORR) performance of lignin-based electrospun carbon fibers was studied. The fibers were spun from a lignin-ethanol solution free of any binder, where different Pd salts were added at two concentration levels. The system implemented to perform the spinning was a coaxial setup in which the internal flow contains the precursor dispersion with the metallic precursor, and ethanol was used as external flow to help fiber formation and prevent drying before generating the Taylor cone. The obtained cloths were thermostabilized in air at 200 °C and carbonized in nitrogen at 900 °C. The resulting carbon fibers were characterized by physicochemical and electrochemical techniques. The palladium precursor significantly affects nanoparticle distribution and size, fiber diameter, pore distribution, surface area and electrochemical behavior. The fibers prepared with palladium acetylacetonate at high Pd loading and carbonized at 900 °C under a CO₂ atmosphere showed high mechanical stability and the best ORR activity, showing near total selectivity towards the 4-electron path. These features are comparable to those of the commercial Pt/C catalyst but much lower metal loading (10.6 wt.% vs. 20 wt.%). The most promising fibers have been evaluated as cathodes in a zinc–air battery, delivering astonishing stability results that surpassed the performance of commercial Pt/C materials in both charging and discharging processes. Full article

(This article belongs to the Special Issue Materials for Emerging Electrochemical Devices—2nd Edition)

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38 pages, 3321 KiB

Open AccessReview

Conventional and Novel Strategies for Cellulose Isolation from Nut Shells: A Review

by Andrea Están, Mónica Umaña, Valeria S. Eim, Gabriela Clemente and Susana Simal

Molecules 2025, 30(12), 2486; https://doi.org/10.3390/molecules30122486 - 6 Jun 2025

Abstract

Nut by-products, particularly shells, are a globally abundant agricultural residue. Their widespread accumulation poses a serious environmental challenge. However, nut shells are of great interest due to their inherent lignocellulosic composition. For instance, they are rich in cellulose, a high-value biopolymer widely used [...] Read more.

Nut by-products, particularly shells, are a globally abundant agricultural residue. Their widespread accumulation poses a serious environmental challenge. However, nut shells are of great interest due to their inherent lignocellulosic composition. For instance, they are rich in cellulose, a high-value biopolymer widely used in the production of bio-based materials. Therefore, this review critically analyses conventional and novel pre-treatment strategies for the extraction of cellulose from nut shells, emphasising the importance of optimising valorisation routes to minimise ecological impact. Various techniques—ranging from alkaline treatments to emerging approaches such as deep eutectic solvents and hydrothermal methods—have been examined and compared. The findings in cellulose purification through different strategies reveal that, while some methods are promising, others remain underexplored. Emphasis is placed on the necessity of comprehending the specific structural and chemical characteristics of each type of nut shell; as such, knowledge is fundamental to understanding the efficiency of the applied methods. This review highlights the growing interest in the valorisation of nut shell by-products as promising lignocellulosic resources of significant utility. Therefore, it also reveals the need for further research, focusing on process scalability, cost-efficiency, and environmental impact. Advancing in these areas is essential to enable the transition of nut shells from waste to a highly valuable resource. Full article

(This article belongs to the Special Issue Featured Reviews in Applied Chemistry 2.0)

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13 pages, 970 KiB

Open AccessArticle

Chemical Profiles and Biological Activities of Essential Oil from Serissa japonica

by Ty Viet Pham, Thien-Y Vu and Hien Minh Nguyen

Molecules 2025, 30(12), 2485; https://doi.org/10.3390/molecules30122485 - 6 Jun 2025

Abstract

This study was the first to analyze the chemical compositions and bioactivities of Serissa japonica leaf oil. The oil, obtained via hydro-distillation with a 0.1% yield, contained 64 compounds, predominantly non-terpenic compounds (39.0%), oxygenated sesquiterpenes (31.4%), and oxygenated monoterpenes (25.6%). Major constituents included [...] Read more.

This study was the first to analyze the chemical compositions and bioactivities of Serissa japonica leaf oil. The oil, obtained via hydro-distillation with a 0.1% yield, contained 64 compounds, predominantly non-terpenic compounds (39.0%), oxygenated sesquiterpenes (31.4%), and oxygenated monoterpenes (25.6%). Major constituents included 1,8-cineole, (E)-nerolidol, and iso-longifolol. The oil showed good antioxidant activity (IC₅₀ ≈ 62.79 ± 0.77 µg/mL for DPPH and 57.82 ± 1.12 µg/mL for ABTS) and a good anti-tyrosinase effect (IC₅₀ ≈ 195.6 ± 3.82 µg/mL). The trend was similar to anti-inflammatory activity, with an IC₅₀ value of 63.03 ± 3.22, for NO inhibition without cytotoxicity at 100 µg/mL. The bovine serum albumin (BSA) blocking assay demonstrated an IC₅₀ value of 59.31 ± 0.71 µg/mL, indicating a good interaction regarding enzyme inhibition. Moreover, the computational modeling of the possible association between tyrosinase and cyclooxygenase-2 highlighted their antioxidant and anti-inflammatory properties. The results pointed out the usefulness of S. japonica essential oil as a natural candidate for managing oxidative stress and inflammation. Full article

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28 pages, 5628 KiB

Open AccessArticle

Rice Husks as a Biogenic Template for the Synthesis of Fe₂O₃/MCM-41 Nanomaterials for Polluted Water Remediation

by Tamara B. Benzaquén, Paola M. Carraro, Griselda A. Eimer, Julio Urzúa-Ahumada, Po S. Poon and Juan Matos

Molecules 2025, 30(12), 2484; https://doi.org/10.3390/molecules30122484 - 6 Jun 2025

Abstract

This work shows a sustainable methodology for the synthesis of biogenic materials designed for the removal and photodegradation of rhodamine B (RhB), a highly dangerous environmental pollutant that induces reproductive toxicity. The classical synthesis of MCM-41-ordered mesoporous materials was modified using biocompatible rice [...] Read more.

This work shows a sustainable methodology for the synthesis of biogenic materials designed for the removal and photodegradation of rhodamine B (RhB), a highly dangerous environmental pollutant that induces reproductive toxicity. The classical synthesis of MCM-41-ordered mesoporous materials was modified using biocompatible rice husk as the silica template. Iron was incorporated and the so-prepared biogenic photocatalysts were characterized by X-ray diffraction, N₂ adsorption–desorption isotherms, transmission electron microscopy, diffuse reflectance UV-Vis, surface pH, cyclic voltammetry, and Fourier transform infrared spectral analysis of pyridine adsorption. The photocatalytic performance of the materials was evaluated following the removal by adsorption and the photon-driven degradation of RhB. The adsorption capacity and photocatalytic activity of the biogenic materials were correlated with their properties, including iron content, texture, surface content, and electrochemical properties. The best biogenic material boosted the degradation rates of RhB under UV irradiation up to 4.7 and 2.2 times greater than the direct photolysis and the benchmark semiconductor TiO₂-P25. It can be concluded that the use of rice husks for the synthesis of biogenic Fe-modified mesoporous materials is a promising strategy for wastewater treatment applications, particularly in the removal of highly toxic organic dyes. Full article

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

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18 pages, 753 KiB

Open AccessSystematic Review

Graphene Quantum Dots for Glioblastoma Treatment and Detection–Systematic Review

by Kacper Kregielewski, Wiktoria Fraczek and Marta Grodzik

Molecules 2025, 30(12), 2483; https://doi.org/10.3390/molecules30122483 - 6 Jun 2025

Abstract

Glioblastoma, a highly malignant tumor, has a poor prognosis, necessitating the development of effective therapeutic strategies due to the low success rates of existing treatments. Graphene quantum dots (GQDs) have garnered attention for their unique physicochemical, electronic, and optical properties, along with biocompatibility [...] Read more.

Glioblastoma, a highly malignant tumor, has a poor prognosis, necessitating the development of effective therapeutic strategies due to the low success rates of existing treatments. Graphene quantum dots (GQDs) have garnered attention for their unique physicochemical, electronic, and optical properties, along with biocompatibility and the ability to cross the blood–brain barrier. This systematic review evaluates the current applications of GQDs in glioblastoma management. A search across databases such as PubMed, Science Direct, and Web of Science identified 658 papers, with 10 selected for this review based on the eligibility criteria. Most of the selected studies explored GQDs as pretreatment agents for therapies like chemotherapy and photothermal therapy, alongside their roles in biosensing, bioimaging, and drug delivery. Although research is still limited, this review highlights the significant potential of GQDs as multifunctional platforms in glioblastoma therapy. Further studies are essential to optimize these nanostructures for clinical applications, aiming to improve the precision and effectiveness of treatments while reducing systemic side effects. Full article

(This article belongs to the Special Issue Low-Dimensional Nanomaterials: Chemical Functionalization and Advanced Applications)

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12 pages, 1037 KiB

Open AccessArticle

Influence of Biopolymer–Biopolymer Interactions on Selected Rheological Properties of Aqueous Ionic Hydrocolloid Solutions

by Joanna Kruk, Kacper Kaczmarczyk, Paweł Ptaszek and Anna Ptaszek

Molecules 2025, 30(12), 2482; https://doi.org/10.3390/molecules30122482 - 6 Jun 2025

Abstract

The influence of biopolymer–biopolymer chain interactions on selected rheological properties of aqueous solutions from konjac (KG), xanthan gum (XG), and carboxymethyl cellulose (CMC) was investigated using viscosity measurements in extensional and shear flow, as well as normal force (

F_{N}

) measurements [...] Read more.

The influence of biopolymer–biopolymer chain interactions on selected rheological properties of aqueous solutions from konjac (KG), xanthan gum (XG), and carboxymethyl cellulose (CMC) was investigated using viscosity measurements in extensional and shear flow, as well as normal force (

F_{N}

) measurements generated in shear flow. It was found that a KG solution of 0.05% behaves as a Newtonian fluid. Other solutions of KG (0.1, 0.2%), XG, and CMC revealed a non-linear dependence of viscosity on the shear rate. The extensional viscosity dependence on the elongation rate was non-linear and indicated shear-thinning over the entire KG concentration range, with the lowest values noted at 0.05% (0.5–0.8 Pas) and the highest at 0.2% (1.0–1.3 Pas). Similar observations were obtained with 0.1% XG and CMC solutions. Analysis regarding the shear rate dependence of the

F_{N}

showed that hysteresis was observed for all KG concentrations tested. Only for the 0.2% KG solution were the

F_{N}

values negative over the entire range of shear rates estimated, as in the case of the XG and CMC solutions. The obtained time constants from the DeKee model indicate the dominance of elastic contributions for the XG and CMC solutions and viscous contributions for the CMC solutions in the case of an extensional flow. Full article

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1 pages, 136 KiB

Open AccessRetraction

RETRACTED: Sun et al. Resveratrol Inhibits the Migration and Metastasis of MDA-MB-231 Human Breast Cancer by Reversing TGF-β1-Induced Epithelial-Mesenchymal Transition. Molecules 2019, 24, 1131

by Yang Sun, Qian-Mei Zhou, Yi-Yu Lu, Hui Zhang, Qi-Long Chen, Ming Zhao and Shi-Bing Su

Molecules 2025, 30(12), 2481; https://doi.org/10.3390/molecules30122481 - 6 Jun 2025

Abstract

The Molecules journal retracts the article titled “Resveratrol Inhibits the Migration and Metastasis of MDA-MB-231 Human Breast Cancer by Reversing TGF-β1-Induced Epithelial-Mesenchymal Transition” [...] Full article

11 pages, 1775 KiB

Open AccessArticle

ZIF-8 as Potential Pesticide Adsorbent Medium for Wastewater Treatment: The Case Study of Model Linuron Extraction Conditions Optimization via Design of Experiment

by Nicola di Nicola, Mariacristina Di Pelino, Martina Foschi, Rosalba Passalacqua, Andrea Lazzarini and Fabrizio Ruggieri

Molecules 2025, 30(12), 2480; https://doi.org/10.3390/molecules30122480 - 6 Jun 2025

Abstract

The increasing presence of pesticide residues in aquatic environments poses a significant threat to ecosystems and human health, necessitating the development of effective removal technologies. In this study, Zeolitic Imidazolate Framework-8 (ZIF-8) was investigated as adsorbent for Linuron, a widely used herbicide. The [...] Read more.

The increasing presence of pesticide residues in aquatic environments poses a significant threat to ecosystems and human health, necessitating the development of effective removal technologies. In this study, Zeolitic Imidazolate Framework-8 (ZIF-8) was investigated as adsorbent for Linuron, a widely used herbicide. The material was synthesized via a hydrothermal method and underwent thorough physico-chemical characterization, confirming its intrinsic properties. Adsorption experiments were conducted under systematically varied conditions using a Central Composite Face-Centered (CFC) experimental design, evaluating the effects of temperature, Linuron concentration, ionic strength on adsorption efficiency. The Response Surface Methodology (RSM) revealed that temperature and Linuron concentration were the most influential variables. A quadratic effect of ionic strength and a significant interaction between Linuron concentration and ionic strength were also observed. The fitted quadratic regression model exhibited excellent predictive performance (R² = 0.909; Q² = 0.755), and analysis of variance (ANOVA) confirmed its significance (p < 0.001) with a non-significant lack of fit. Maximum Linuron removal (>95%) was achieved at elevated temperature, moderate concentration, and intermediate ionic strength. These findings highlight the potential of ZIF-8 as a tunable and high-efficiency adsorbent for the remediation of pesticide-contaminated water, demonstrating the value of RSM-based optimization in designing adsorption processes. Full article

(This article belongs to the Special Issue Wastewater Treatment: Functional Materials and Advanced Technology, 2nd Edition)

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13 pages, 320 KiB

Open AccessReview

Conventional Near-Infrared Spectroscopy and Hyperspectral Imaging: Similarities, Differences, Advantages, and Limitations

by Daniel Cozzolino

Molecules 2025, 30(12), 2479; https://doi.org/10.3390/molecules30122479 - 6 Jun 2025

Abstract

Although, the use of sensors is increasing in a wide range of fields with great success (e.g., food, environment, pharma, etc.), their uptake is slow and lower than other innovations. While the uptake is low, some users, producers, and service industries are continuing [...] Read more.

Although, the use of sensors is increasing in a wide range of fields with great success (e.g., food, environment, pharma, etc.), their uptake is slow and lower than other innovations. While the uptake is low, some users, producers, and service industries are continuing to benefit from the incorporation of technology in their business. Among these technologies, vibrational spectroscopy has demonstrated its benefits and versatility in a wide range of applications. Both conventional near-infrared (NIR) spectroscopy and hyperspectral imaging (HSI) systems are two of the main techniques utilized in a wide range of applications in different fields. These techniques use the NIR region of the electromagnetic spectrum (750–2500 nm). Specifically, NIR-HSI systems provide spatial information and spectral data, while conventional NIR spectroscopy provides spectral information from a single point. Even though there is a clear distinction between both techniques in terms of their benefits, confusion still exists among users about their similarities and differences. This paper provides a critical discussion of the main advantages and limitations of both techniques, focusing on food science applications. Full article

(This article belongs to the Special Issue Materials Investigation Through Vibrational Spectroscopy/Microscopy)

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13 pages, 2535 KiB

Open AccessArticle

Synthesis and Properties of Energetic MOFs Based on Bis(3-Nitro-1H-1,2,4-triazole-5-yl) Amine: Advancing High Thermal Stability and Low Sensitivity

by Shiluo Chen, Jinxin Wang, Yuteng Cao, Kangcai Wang, Haijun Yang and Tianlin Liu

Molecules 2025, 30(12), 2478; https://doi.org/10.3390/molecules30122478 - 6 Jun 2025

Abstract

Energetic metal–organic frameworks (E-MOFs) have recently emerged as a promising strategy to address the long-standing challenge of reconciling energy and sensitivity in energetic materials. Nitrogen-rich compounds, with their abundant nitrogen atoms and superior enthalpy of formation, are particularly beneficial for forming multiple coordination [...] Read more.

Energetic metal–organic frameworks (E-MOFs) have recently emerged as a promising strategy to address the long-standing challenge of reconciling energy and sensitivity in energetic materials. Nitrogen-rich compounds, with their abundant nitrogen atoms and superior enthalpy of formation, are particularly beneficial for forming multiple coordination bonds while simultaneously elevating the energy content. This makes them ideal ligand molecules for constructing E-MOFs. In this work, we report the synthesis and structural design of a novel series of E-MOFs, constructed from the nitrogen-rich energetic ligand BNTA and a range of alkali metals (Na–Rb, compounds 2–5). The research indicates that the synthesized E-MOFs exhibit high thermal stability and low sensitivity. Specifically, Compound 3 displays a high decomposition temperature of 285 °C, with impact sensitivity and friction sensitivity values exceeding 40 J and 360 N, respectively. Moreover, Compound 3 also exhibits excellent computational detonation performance. Significantly, this study demonstrates how the aromatic character, coordination chemistry, and intermolecular interactions work synergistically to enhance the stability and safety of E-MOFs, thereby establishing fundamental criteria for engineering the next generation of energetic frameworks. Full article

(This article belongs to the Special Issue Molecular Design and Synthesis of Novel Energetic Compounds)

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Molecules, Volume 30, Issue 12 (June-2 2025) – 24 articles

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