Molecules

27 pages, 10911 KB

Open AccessReview

Noble Metal Functionalized Metal Oxide Semiconductors for Enhanced Gas Sensing

by Renqing Yao, Yi Xia, Li Yang, Jincheng Xiang, Qiuni Zhao and Shenghui Guo

Molecules 2025, 30(24), 4683; https://doi.org/10.3390/molecules30244683 (registering DOI) - 6 Dec 2025

Gas sensors are vital tools in areas such as environmental monitoring, industrial safety, and personal healthcare. Among various sensing materials, semiconductor metal oxides (SMOs) are widely studied owing to their high sensitivity, good stability, and notable catalytic activity. To overcome inherent drawbacks of [...] Read more.

Gas sensors are vital tools in areas such as environmental monitoring, industrial safety, and personal healthcare. Among various sensing materials, semiconductor metal oxides (SMOs) are widely studied owing to their high sensitivity, good stability, and notable catalytic activity. To overcome inherent drawbacks of pure SMOs—such as high operating temperatures, limited selectivity, sluggish response/recovery behavior, and inadequate long-term stability—functionalization with noble metals has emerged as a powerful modification strategy. This review systematically outlines the primary mechanisms through which noble metals enhance gas sensing performance and analyzes the key factors influencing sensor behavior. Finally, we discuss the current challenges and future directions in the development of noble metal-modified SMO gas sensors. Full article

(This article belongs to the Section Materials Chemistry)

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Graphical abstract

27 pages, 2299 KB

Open AccessArticle

Organ-Specific Distribution of Antimycobacterial Neolignans in Piper rivinoides and UHPLC-HRMS/MS Analysis of Its Extracts

by Jéssica Sales Felisberto, Thayssa Ferreira Fagundes, Lorraynne Oliveira-Souza, Bruno Henrique Gomes de Souza, Daniel Machado de Brito, Jeferson Adriano Assunção, Samik Lourenço Massau, Marlon H. de Araújo, Michelle Frazão Muzitano, Sanderson Dias Calixto, Thatiana Lopes Biá Ventura Simão, Andre Mesquita Marques, Ygor Jessé Ramos and Davyson de Lima Moreira

Molecules 2025, 30(24), 4682; https://doi.org/10.3390/molecules30244682 (registering DOI) - 6 Dec 2025

Abstract

This multidisciplinary study investigates Piper rivinoides, a Brazilian medicinal species, focusing on its chemical composition and antimycobacterial potential. UHPLC-HRMS/MS of leaves, stems, branches, and roots revealed 58 compounds, including neolignans, lignanamides, triterpenes, flavonoids, and carotenoids. Fourteen metabolites, notably benzofuran neolignans and pentacyclic [...] Read more.

This multidisciplinary study investigates Piper rivinoides, a Brazilian medicinal species, focusing on its chemical composition and antimycobacterial potential. UHPLC-HRMS/MS of leaves, stems, branches, and roots revealed 58 compounds, including neolignans, lignanamides, triterpenes, flavonoids, and carotenoids. Fourteen metabolites, notably benzofuran neolignans and pentacyclic triterpenes are annotated here for the first time. Quantitative analyses by HPLC-DAD-UV showed that eupomatenoid-5, eupomatenoid-6, and conocarpan were most abundant in leaves, reaching amounts approximately twice those found in branches and stems and about ten times higher than in roots, supporting the optimal defense theory and organ-specific accumulation of bioactive metabolites. Biological assays against Mycobacterium tuberculosis strains H37Rv and M299 revealed strong inhibitory activity for the leaf extract and isolated neolignans. Eupomatenoid-5 and eupomatenoid-6 achieved inhibition comparable to rifampicin, with low MIC₅₀ values, while conocarpan exhibited moderate activity. Antimycobacterial effects were more pronounced against the H37Rv strain, although relevant inhibition was also observed for the hypervirulent M299 strain. These findings highlight P. rivinoides as a rich source of benzofuran neolignans and promising antimycobacterial properties. The integration of advanced mass spectrometric analyses with bioassays demonstrates the value of combining chemical and biological approaches to uncover novel natural products. The putative identification of new neolignans and triterpenes, along with the confirmation of potent antimycobacterial activity, provides a robust foundation for further studies on biosynthesis, structure–activity relationships, and potential biotechnological applications. Full article

(This article belongs to the Section Natural Products Chemistry)

25 pages, 2159 KB

Open AccessReview

Synthetic Flozins in Cancer Prevention and Combination Strategies: Structural Insights and Therapeutic Potential

by Michał Zieliński, Olga Michalak, Magdalena Ruszczak and Marcin Cybulski

Molecules 2025, 30(24), 4681; https://doi.org/10.3390/molecules30244681 (registering DOI) - 6 Dec 2025

Abstract

The growing number of cancer cases highlights the urgent need to develop new therapies based on effective molecules. Although anticancer activity remains a key element of oncological pharmacology, the importance of agents that support physiological functions and improve the quality of life of [...] Read more.

The growing number of cancer cases highlights the urgent need to develop new therapies based on effective molecules. Although anticancer activity remains a key element of oncological pharmacology, the importance of agents that support physiological functions and improve the quality of life of cancer patients is also recognised. Compounds that combine these two functions could represent a significant trend in oncology. Moreover, repurposing approved drugs for conditions beyond their original indications could be a promising strategy. An interesting example of this is synthetic flozins (SGLT2 inhibitors), which were originally designed and developed to treat type 2 diabetes mellitus. These compounds contain various aromatic and heteroaryl structures, and changes in these substituents affect the binding strength and therapeutic potency of SGLT2 inhibitors. Beyond their antidiabetic effects, SGLT2 inhibitors exert well-documented cardioprotective and nephroprotective actions, restoring metabolic homeostasis. Given these pleiotropic properties, they could benefit oncology by improving systemic functions and by directly influencing the invasion of cancer cells. This article provides an overview of the use of synthetic flozins in various contexts, with a particular focus on their potential impact on cancer biology and treatment, consolidating their position as multifunctional agents of growing systemic relevance. Full article

(This article belongs to the Special Issue Organic Molecules in Drug Discovery and Development)

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18 pages, 2311 KB

Open AccessArticle

TD-NMR-Based Determination of the Entrapped Water Yield of Water-in-Oil-in-Water Double Emulsions: Influence of Xanthan Gum Addition

by Yulin Hu, Ferre Rebry and Paul Van der Meeren

Molecules 2025, 30(24), 4680; https://doi.org/10.3390/molecules30244680 (registering DOI) - 6 Dec 2025

Abstract

Water-in-oil-in-water (W/O/W) double emulsions (DEs) are considered promising systems for encapsulating, protecting, and delivering hydrophilic compounds. However, their thermodynamic instability limits their practical application. The addition of stabilizers and/or thickeners is a straightforward strategy to improve their stability. However, the high viscosity of [...] Read more.

Water-in-oil-in-water (W/O/W) double emulsions (DEs) are considered promising systems for encapsulating, protecting, and delivering hydrophilic compounds. However, their thermodynamic instability limits their practical application. The addition of stabilizers and/or thickeners is a straightforward strategy to improve their stability. However, the high viscosity of DEs complicates the accurate determination of their entrapped water yield (EY), especially when applying techniques based on phase separation. In this study, two TD-NMR-based techniques (T₂ relaxometry, and NMR diffusometry) were compared to analytical photocentrifugation to evaluate their effectiveness in determining the entrapped water yield of DEs formulated with various concentrations (0–0.8 wt%) of xanthan gum (Xan) in the external aqueous (W₂) phase. For EY determination, analytical photocentrifugation led to overestimated results for DEs containing xanthan, primarily due to the high viscosity, which inhibited the complete separation between the cream and serum layers. In contrast, after optimizing measurement and analysis conditions to minimize interference from water and/or solute exchange between the inner and outer aqueous phases, T₂ relaxometry and NMR diffusometry yielded comparable EY values for all DEs with or without Xan. Hence, these two TD-NMR-based techniques can be considered direct and reliable methods for EY determination in viscous DE system. Full article

(This article belongs to the Special Issue NMR and MRI in Materials Analysis: Opportunities and Challenges)

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17 pages, 2377 KB

Open AccessArticle

Natural Phytotherapeutics in Dermatology and Cosmetology: Bioactive Potential of Grape Pomace on Human Skin Fibroblasts

by Barbara Domagała, Julia Orlińska, Małgorzata Duda, Zuzanna Setkowicz-Janeczko, Marzena Starzyk, Ewelina Piasna-Słupecka, Mariola Drozdowska and Ewa Godos

Molecules 2025, 30(24), 4679; https://doi.org/10.3390/molecules30244679 (registering DOI) - 6 Dec 2025

Abstract

The aim of the study was to assess the biological potential of extracts obtained from the grape pomace of three Vitis vinifera hybrid varieties—Regent, Rondo and Marechal Foch—as a natural source of bioactive compounds, with possible application in cosmetology and dermatology. Grape pomace, [...] Read more.

The aim of the study was to assess the biological potential of extracts obtained from the grape pomace of three Vitis vinifera hybrid varieties—Regent, Rondo and Marechal Foch—as a natural source of bioactive compounds, with possible application in cosmetology and dermatology. Grape pomace, which is an important by-product of the winemaking process, is a rich source of polyphenols, flavonoids, anthocyanins and vitamin C, which exhibit antioxidant, anti-inflammatory and cytoprotective properties that are important for skin health. The conducted studies determined the antioxidant activity of the extracts (DPPH) and the content of total phenolic compounds, flavonoids, anthocyanins and vitamin C, Of the varieties analysed: Marechal Foch exhibited the highest antioxidant activity (10 µmol TE/g), while Regent demonstrated the highest flavonoid content (50.42 mg/g) and vitamin C content (35.6 mg/100 g). The Rondo extract had the highest content of anthocyanins (362.36 mg/g) and total phenolic compounds (18.31 mg/g), indicating strong protective potential for skin cells. Regent extract at a concentration of 25 μg/mL was found to have the greatest effect on fibroblast proliferation and migration, significantly increasing the percentage of living cells and the rate of regeneration. This correlates with the high flavonoid content, which is particularly important for skin cells. These results confirm that grape pomace, particularly from the Regent variety, is a valuable source of natural antioxidants with anti-aging and regenerative properties. The use of these raw materials in cosmetic formulations aligns with the principles of the circular economy and the idea of “zero waste”, being an example of the sustainable use of by-products from the wine industry in the production of innovative bio-cosmetics. Full article

(This article belongs to the Special Issue Advances in Chemistry of Cosmetics)

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43 pages, 10806 KB

Open AccessArticle

An MD View of Ligand Binding

by Adrian Calderon, Eric Harbinson, Rüdiger Ettrich, Natalia Kulik and Jannette Carey

Molecules 2025, 30(24), 4678; https://doi.org/10.3390/molecules30244678 (registering DOI) - 6 Dec 2025

Abstract

Protein–ligand complexes in crystal structures are well described by an array of bonding interactions among precisely defined functional groups. The present work examines how one representative complex behaves in one-microsecond molecular dynamics simulations, starting from a crystal structure with a native biological ligand [...] Read more.

Protein–ligand complexes in crystal structures are well described by an array of bonding interactions among precisely defined functional groups. The present work examines how one representative complex behaves in one-microsecond molecular dynamics simulations, starting from a crystal structure with a native biological ligand bound, and proceeding to simulations of structures derived by docking of that native ligand, and then to docking of selected ligand analogs. The MD behaviors and system energies calculated in RMSD plateau regions using MM/GBSA are similar when initiated from the crystal structure or the structure with the docked native ligand, although independent replicate simulations differ. Despite these similarities, interatomic contact frequencies indicate that some contacts observed in the crystal structure are rarely sampled again; others are sampled only intermittently; and new contacts are recruited that can be more persistent. Docked structures of non-native ligand analogs were chosen for simulation by screening manually for features consistent with known binding interactions, and these displayed behaviors similar to those for the native ligand and, in some cases, similar calculated energies. Overall, ligands appear to cooperate dynamically with the protein in forming the observed interactions. Full article

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25 pages, 759 KB

Open AccessArticle

Impact of Viburnum opulus L. Fruit Extracts on the Physicochemical, Sensory, and Bioactive Properties of Wheat Waffles

by Begümhan Ömeroğlu Gülada, Urszula Złotek, Urszula Gawlik, Dariusz Kowalczyk, Duygu Taşkın, Turgut Taşkın, Anna Jakubczyk and Fatma Esra Güneş

Molecules 2025, 30(24), 4677; https://doi.org/10.3390/molecules30244677 - 5 Dec 2025

Abstract

This study aimed to compare the phenolic profiles and bioactive properties of powdered aqueous (AVOE) and methanolic (MVOE) Viburnum opulus L. fruit extracts and compare the effect of increasing concentrations of these extracts on the physicochemical, sensory, and bioactive properties of wheat waffles. [...] Read more.

This study aimed to compare the phenolic profiles and bioactive properties of powdered aqueous (AVOE) and methanolic (MVOE) Viburnum opulus L. fruit extracts and compare the effect of increasing concentrations of these extracts on the physicochemical, sensory, and bioactive properties of wheat waffles. The polyphenol content and bioactivity of the extracts and waffles were assessed based on their water–ethanol and phosphate-buffered saline extracts, as well as on samples after in vitro digestion. MVOE and MVOE-enriched waffles showed superior, statistically significant antioxidant and anti-inflammatory activity compared to AVOE and AVOE-enriched waffles. Functional analyses revealed that the enrichment level affected water absorption, texture, and sensory perception, with reduced acceptability at high aqueous extract levels. Overall, methanolic extract enrichment provided the best balance between functionality and bioactivity, and waffles enriched with the highest amount of MVOE were characterized by having the highest potentially bioavailable polyphenol fraction (17.47 ± 1.01 mg GAE/gDW) as well as the strongest ability to inhibit LOX and XO activity (EC₅₀ = 8.55 ± 0.16 and 9.25 ± 0.01 mgDW/mL, respectively) with simultaneous high consumer acceptability. These results confirm the applicability of VO extracts in food formulations and potential health benefits, offering a basis for future clinical studies on VO-enriched functional foods. Full article

(This article belongs to the Special Issue New Achievements and Challenges in Food Chemistry)

12 pages, 2299 KB

Open AccessArticle

Proline-Free Local Turn via N-Oxidation: Crystallographic and Solution Evidence for a Six-Membered N–O⋯H–N Ring

by Renlin Zheng, Wenjiao Zhao, Shuo Yuan, Tong Wang, Wenyu Lu, Qian Meng, Li Yang and Dequn Sun

Molecules 2025, 30(24), 4676; https://doi.org/10.3390/molecules30244676 - 5 Dec 2025

Abstract

N-oxides are emerging as versatile tools for modulating peptide conformation due to their strong proton-accepting ability and distinct electronic properties. In this study, we report the first crystallographic evidence that an N-oxidized peptide (NOP 5) containing a proline residue forms an intramolecular [...] Read more.

N-oxides are emerging as versatile tools for modulating peptide conformation due to their strong proton-accepting ability and distinct electronic properties. In this study, we report the first crystallographic evidence that an N-oxidized peptide (NOP 5) containing a proline residue forms an intramolecular six-membered hydrogen bond between the N-oxide oxygen and an adjacent amide proton. This conformational motif is not restricted to proline-containing sequences: NMR spectroscopic analyses (including DMSO-d₆ titration, VT-NMR, NOE, and concentration-dependent studies) reveal that NOPs 7 and 9, in which proline is replaced by glycine, adopt the same hydrogen-bonded ring structure in aprotic solvents. Remarkably, this conformation persists even in protic solvent (CD₃OH), indicating the robustness of the N-oxide-induced hydrogen bond. DFT calculations further support the experimental findings and rationalize the conformational preferences of NOPs 5 and 7. These results establish N-oxide as a potent and generalizable constraint for stabilizing peptide secondary structures, offering a new strategy for the design of peptidomimetics with tunable rigidity and solvent stability. Full article

(This article belongs to the Section Chemical Biology)

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15 pages, 5457 KB

Open AccessArticle

The UV-Visible Absorption Spectra of Coumarin and Nile Red in Aqueous Solution: A Polarizable QM/MM Study

by Tommaso Giovannini, Matteo Ambrosetti and Chiara Cappelli

Molecules 2025, 30(24), 4675; https://doi.org/10.3390/molecules30244675 - 5 Dec 2025

Abstract

We present a comprehensive computational study of the UV-visible absorption spectra of 7-methoxycoumarin and Nile red in aqueous solution. Our fully atomistic workflow couples classical molecular dynamics (MD) with polarizable QM/MM based on fluctuating charges (QM/FQ) and dipoles (QM/FQF

μ

). Ensemble-averaged spectra [...] Read more.

We present a comprehensive computational study of the UV-visible absorption spectra of 7-methoxycoumarin and Nile red in aqueous solution. Our fully atomistic workflow couples classical molecular dynamics (MD) with polarizable QM/MM based on fluctuating charges (QM/FQ) and dipoles (QM/FQF

μ

). Ensemble-averaged spectra are constructed from the snapshots extracted from the MD, embedding solvent fluctuations and specific solute–solvent interactions in the electronic response of organic dyes. The spectral profiles, obtained at the various levels, reflect the underlying solute–solvent interactions and dynamics, and we rationalize them in terms of hydrogen bonding and frontier molecular orbitals involved in the main electronic transitions. Finally, the simulated spectra and solvatochromic shifts are compared with the available experimental data, showing an overall good agreement and demonstrating the robustness of the computational protocol. Full article

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

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22 pages, 3098 KB

Open AccessArticle

Tuning CO₂ Absorption in Hydrophobic Protic Ionic Liquids via Temperature and Structure

by Nurin Athirah Mohd Mazlan, Madelyn Wen Qian Teoh, Asyraf Hanim Ab Rahim, Gani Purwiandono and Normawati M. Yunus

Molecules 2025, 30(24), 4674; https://doi.org/10.3390/molecules30244674 - 5 Dec 2025

Abstract

Conventional amine-based solvents such as monoethanolamine (MEA) and diethanolamine (DEA) are widely used for CO₂ removal from natural gas but this technology suffers from drawbacks including high regeneration energy, solvent degradation, and corrosion issues. To overcome these limitations, this study investigates the [...] Read more.

Conventional amine-based solvents such as monoethanolamine (MEA) and diethanolamine (DEA) are widely used for CO₂ removal from natural gas but this technology suffers from drawbacks including high regeneration energy, solvent degradation, and corrosion issues. To overcome these limitations, this study investigates the use of newly synthesized hydrophobic protic ionic liquids (HPILs) composed of ammonium cations coupled with the bis(trifluoromethane)sulfonylimide ([Tf₂N]⁻) anion for CO₂ absorption using the pressure-drop method. The results show that CO₂ solubility increases with pressure but decreases with temperature. Among the studied ionic liquids (ILs), [BEHA][Tf₂N] exhibits the highest CO₂ capacity at 298.15 K within the pressure range of 1–20 bar, which is consistent with its free volume (V_f) value. Furthermore, a comparison study indicates that all ILs demonstrate superior CO₂ selectivity over methane (CH₄) at 298.15 K. The recyclability study shows that [BEHA][Tf₂N] maintains its structural integrity over two CO₂ absorption cycles at 20 bar across all tested temperatures. Full article

(This article belongs to the Special Issue Ionic Liquids and Molecular Materials: Advances in Functional Interfaces and Applications)

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22 pages, 3931 KB

Open AccessArticle

Protective Metabolic Effects of Chickpea Sprout Against Obesity-Induced Insulin Resistance and Hypoestrogenism in Rats

by Patrick Mailloux-Salinas, Cristian Jiménez-Martínez, David Julian Arias-Chávez, Arturo Armando Gordillo-Bernal, María Stephanie Cid-Gallegos, Liliana Alamilla-Beltrán and Guadalupe Bravo

Molecules 2025, 30(24), 4673; https://doi.org/10.3390/molecules30244673 - 5 Dec 2025

Abstract

Obesity and menopausal hypoestrogenism interact in a way that worsens insulin resistance and increases the risk of metabolic diseases. This study evaluated the effects of a diet composed of liquid chickpea sprouts (CS) on these problems. Sixty-four female Wistar rats were assigned to [...] Read more.

Obesity and menopausal hypoestrogenism interact in a way that worsens insulin resistance and increases the risk of metabolic diseases. This study evaluated the effects of a diet composed of liquid chickpea sprouts (CS) on these problems. Sixty-four female Wistar rats were assigned to four experimental groups: a control group (Ctrl); a hypoestrogenic (HE) group, induced by ovariotomy; an obese (Ob) group, fed a high-sucrose diet; and a hypoestrogenic-obese (HE-Ob) group. Each group was subdivided into animals treated with chickpea sprouts (CS, 0.9 g/kg/day) or with a vehicle for four weeks. The results showed that CS significantly improved glucose tolerance and restored insulin sensitivity, normalizing the HOMA-IR index in both the Ob and HE-Ob groups. In addition, CS reduced serum triglycerides, reversed hepatic steatosis, and caused a favorable redistribution of adipose tissue, leading to decreased mesenteric fat accumulation. In conclusion, chickpea sprouts have protective metabolic effects by improving glucose homeostasis, reducing blood lipids, and mitigating liver damage in an estrogen-deficient model of obesity. These findings support the potential of chickpea sprouts as a dietary intervention to help prevent metabolic complications in obese postmenopausal women. Full article

(This article belongs to the Special Issue Bioactive Molecules from Natural Sources and Their Functions)

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18 pages, 2553 KB

Open AccessArticle

Metallomic Aspects of Stroke and Recovery: ICP-MS Study with Chemometric Analysis

by Bartłomiej Rospond, Aleksander Matusiak, Elżbieta U. Stolarczyk, Joanna Piotrowska, Bartosz Pomierny, Weronika Krzyżanowska, Przemysław W. Szafrański and Przemysław Dorożyński

Molecules 2025, 30(24), 4672; https://doi.org/10.3390/molecules30244672 - 5 Dec 2025

Abstract

Stroke remains a leading cause of death and disability worldwide, yet the contribution of elemental imbalance to its pathogenesis is not fully understood. Experimental evidence suggests that disturbances in the concentrations of essential and toxic elements contribute to neuronal injury through excitotoxicity, oxidative [...] Read more.

Stroke remains a leading cause of death and disability worldwide, yet the contribution of elemental imbalance to its pathogenesis is not fully understood. Experimental evidence suggests that disturbances in the concentrations of essential and toxic elements contribute to neuronal injury through excitotoxicity, oxidative stress, and inflammation. In this study, we examined regional concentration in 15 elements (Na, K, Ca, Mg, P, Fe, Zn, Cu, Mn, Se, Cr, V, Pb, Al, B) in the subacute phase of ischemic stroke using the middle cerebral artery occlusion (MCAO) rat model. Male Sprague–Dawley rats underwent MCAO or sham surgery, after which the contralateral cortex, dorsal striatum, and hippocampus were collected seven days post-surgery. Elemental concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS) and analyzed by Student’s t-test, cluster analysis, and principal component analysis (PCA). The t-test revealed widespread changes in Ca, while Na was least affected. PCA identified three principal components that explained 81.63% of the variance, with Mn, Zn, Se, K, Mg, Fe, and P contributing most strongly. Cluster analysis distinguished MCAO from sham groups and revealed region-specific responses. Our findings demonstrate long-lasting, region-dependent elemental imbalance after stroke, suggesting a valuable role of elemental profiling. Future investigations should aim to identify elements whose concentrations exhibit alterations not only within central nervous system regions but also in peripheral compartments, such as blood serum, as these changes may hold significant diagnostic and prognostic value. Full article

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14 pages, 2195 KB

Open AccessArticle

Lighting Up DNA in the Near-Infrared: An Os(II)–pydppn Complex with Light-Switch Behavior

by Emanuela Trovato, Salvatore Genovese, Maurilio Galletta, Sebastiano Campagna, Maria Letizia Di Pietro and Fausto Puntoriero

Molecules 2025, 30(24), 4671; https://doi.org/10.3390/molecules30244671 - 5 Dec 2025

Abstract

The osmium(II) polypyridyl complex [Os(tpy)(pydppn)]²⁺ (tpy = 2,2′:6′,2″-terpyridine; pydppn = 3-(pyrid-2′-yl)-4,5,9,16-tetraaza-dibenzo[a,c]naphthacene) was synthesized and characterized to evaluate the effect of an extended planar π-system on photophysical properties and DNA interactions. This complex represents the π-expanded analog of the previously studied [Os(tpy)(pydppz)]²⁺ [...] Read more.

The osmium(II) polypyridyl complex [Os(tpy)(pydppn)]²⁺ (tpy = 2,2′:6′,2″-terpyridine; pydppn = 3-(pyrid-2′-yl)-4,5,9,16-tetraaza-dibenzo[a,c]naphthacene) was synthesized and characterized to evaluate the effect of an extended planar π-system on photophysical properties and DNA interactions. This complex represents the π-expanded analog of the previously studied [Os(tpy)(pydppz)]²⁺ system. Electrochemical studies revealed a reversible Os(II)/Os(III) oxidation at +0.99 V vs. SCE and five ligand-centered reductions, generally less negative than those of the smaller pydppz analog, consistent with enhanced electron-accepting ability. In acetonitrile, the complex exhibits UV absorption bands at 328 and 473 nm and near-infrared emission at 840 nm, assigned to a long-lived ³MLCT state (τ = 110 ns, Φ = 0.02). Upon titration with calf-thymus DNA, [Os(tpy)(pydppn)]²⁺ shows a pronounced light-switch effect, hypochromism, red-shifted MLCT bands, induced circular dichroism, and an increase in DNA melting temperature (ΔT_m = 8.9 ± 0.5 °C), consistent with intercalative binding. Viscometric titrations further support intercalation, with a binding constant K_B ≈ 1.2 × 10⁶ M⁻¹. Transient absorption spectroscopy indicates that DNA binding prolongs the excited-state lifetime and modifies vibrational relaxation pathways. These results highlight how π-system extension in Os(II) complexes modulates photophysical behavior and DNA affinity, offering insights for the rational design of NIR-emitting, DNA-targeted luminescent probes and potential phototherapeutic agents. Full article

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15 pages, 7709 KB

Open AccessArticle

POSS with Vinyl and Epoxy Group to Enhance Dielectric and Thermal Properties of Bismaleimide–Triazine Resins

by Wencheng Gao, Xiaoye Gao, Haosheng Wang and Riwei Xu

Molecules 2025, 30(24), 4670; https://doi.org/10.3390/molecules30244670 - 5 Dec 2025

Abstract

Bismaleimide–triazine (BT) resins are widely utilized in various applications, with ongoing efforts to enhance their performance. In this work, a partially epoxidized polyhedral oligomeric silsesquioxane (PEOVS) containing vinyl and epoxy groups was successfully synthesized, and BT/PEOVS nanocomposites were prepared by blending PEOVS with [...] Read more.

Bismaleimide–triazine (BT) resins are widely utilized in various applications, with ongoing efforts to enhance their performance. In this work, a partially epoxidized polyhedral oligomeric silsesquioxane (PEOVS) containing vinyl and epoxy groups was successfully synthesized, and BT/PEOVS nanocomposites were prepared by blending PEOVS with BT resin. The results revealed that the unique structure of PEOVS significantly improved its dispersion within the resin matrix and enhanced the overall properties of the BT resin. The curing mechanism and properties of BT/PEOVS nanocomposites, with weight ratios of 99.5/0.5, 99/1, 98.5/1.5, 98/2, and 96/4, were analyzed using Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and dielectric measurements. The addition of PEOVS markedly improved the dielectric performance, with a 2% PEOVS content achieving a dielectric constant of 2.39 and a dielectric loss of 0.0036 at 1 MHz. Furthermore, the glass transition temperature and storage modulus were significantly enhanced, with a PEOVS content of 1.5% resulting in a glass transition temperature of 279 °C. The results demonstrate that incorporating PEOVS, featuring dual reactive functional groups, effectively enhances the comprehensive properties of BT resins, providing valuable insights into their modification and practical applications. Full article

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24 pages, 2225 KB

Open AccessArticle

Tetraselmis chuii as Source of Bioactive Compounds Against Helicobacter pylori: An Integrated Proteomic and Bioactivity Approach

by Marta Majchrzak, Samuel Paterson, Pilar Gómez-Cortés, Jose Manuel Silvan, Adolfo J. Martinez-Rodriguez and Blanca Hernández-Ledesma

Molecules 2025, 30(24), 4669; https://doi.org/10.3390/molecules30244669 - 5 Dec 2025

Abstract

Microalgae represent sustainable sources of bioactive compounds with potential health benefits. This study conducted a comprehensive proteomic analysis of Tetraselmis chuii (T. chuii) biomass to identify proteins capable of generating bioactive peptides (BAPs) through simulated orogastric digestion. In silico digestion and [...] Read more.

Microalgae represent sustainable sources of bioactive compounds with potential health benefits. This study conducted a comprehensive proteomic analysis of Tetraselmis chuii (T. chuii) biomass to identify proteins capable of generating bioactive peptides (BAPs) through simulated orogastric digestion. In silico digestion and bioinformatic predictions indicated the release of antioxidant, anti-inflammatory, and antibacterial peptides. Molecular docking demonstrated strong interactions with targets implicated in oxidative stress, inflammation, and Helicobacter pylori (H. pylori) virulence. Biochemical assays and cell-based models confirmed antioxidant and anti-inflammatory activities in both the biomass and its digest, although no significant antibacterial effect against H. pylori was observed under the tested conditions. Considering the role of chronic inflammation in H. pylori-associated pathologies, these findings suggest that T. chuii may serve as a candidate for mitigating tissue damage driven by oxidative and inflammatory stress. Further research is required to address compound stability and optimize delivery strategies. Full article

(This article belongs to the Special Issue Natural Compounds for Disease and Health, 3rd Edition)

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33 pages, 6099 KB

Open AccessArticle

Insight into the Molecular and Structural Changes in Red Pepper Induced by Direct and Indirect Ultrasonic Treatments

by Katarzyna Rybak, Aleksandra Skarżyńska, Szymon Ossowski, Magdalena Dadan, Katarzyna Pobiega and Małgorzata Nowacka

Molecules 2025, 30(24), 4668; https://doi.org/10.3390/molecules30244668 - 5 Dec 2025

Abstract

This study provides a comprehensive assessment of the effect of direct (probe) and indirect (bath) ultrasound treatments on the physicochemical and structural properties of red bell pepper (Capsicum annuum L.) tissue. Ultrasound was applied under controlled conditions to induce structural modification without [...] Read more.

This study provides a comprehensive assessment of the effect of direct (probe) and indirect (bath) ultrasound treatments on the physicochemical and structural properties of red bell pepper (Capsicum annuum L.) tissue. Ultrasound was applied under controlled conditions to induce structural modification without excessive thermal or mechanical damage. The treated samples were evaluated using chemical (polyphenols, flavonoids, carotenoids, vitamin C, sugars), microbiological (total viable count (TVC) and total yeast and mold count (TYM)), spectroscopic (FTIR, NMR), thermal (TGA), and microscopic (SEM, micro-CT) analyses. Both ultrasound modes affected the tissue, but their effects differed in intensity and character. Direct ultrasound caused stronger cavitation and mechanical stress, resulting in greater cell wall disruption, higher permeability, and enhanced release of bioactive compounds such as polyphenols, vitamin C and antioxidants from the tissue matrix to the surroundings. Indirect ultrasound acted more gently, preserving cellular integrity and sugar profile while moderately increasing antioxidant activity. Cluster and correlation analyses confirmed that ultrasound mode was the main factor differentiating the samples. Short-term direct sonication enhanced the release of antioxidant compounds, whereas prolonged exposure led to their degradation, resulting in an overall decline in antioxidant capacity, and indirect ultrasound better preserved texture and sugar composition. This demonstrates that ultrasound mode and duration can be tailored to balance tissue integrity and enhance bioactive compounds in plant-based materials. Full article

(This article belongs to the Special Issue Innovative Technologies for Food Processing and Preservation)

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26 pages, 1676 KB

Open AccessArticle

Synthesis of Substituted 1H-Phenalen-1-ones and Nitrogen-Containing Heterocyclic Analogues as Potential Anti-Plasmodial Agents

by Teresa Abad-Grillo, Grant McNaughton-Smith, Mónica Blanco Freijo, David Gutiérrez and Ninoska Flores

Molecules 2025, 30(24), 4667; https://doi.org/10.3390/molecules30244667 - 5 Dec 2025

Abstract

Given the known biological activity of both natural and synthetic substituted 1H-phenalen-1-ones, the generation of a small chemically and structurally diverse 1H-phenalen-1-one-based library of compounds was warranted. Herein, we have synthesized several groups of compounds to broaden and improve [...] Read more.

Given the known biological activity of both natural and synthetic substituted 1H-phenalen-1-ones, the generation of a small chemically and structurally diverse 1H-phenalen-1-one-based library of compounds was warranted. Herein, we have synthesized several groups of compounds to broaden and improve the chemical diversity of our 1H-phenalen-1-one collection. Additionally, we have also introduced hydroxyl, amides or carboxylic groups onto the core, or nitrogen atoms into the core, to increase the chemical diversity while also lowering the ClogP values to aid their water solubility. Notably, we have also improved the synthetic routes to several compounds of interest and have observed the unexpected formation of phenoxazine and acridin-7-one systems during cross-coupling reactions with polyfunctional anilines. Combining the compounds generated in this work with previous ones has enabled us to create a library of chemically diverse 1H-phenalen-1-one available for screening assays. Evaluation of anti-plasmodial activity against the chloroquine-resistant Plasmodium falciparum strain FCR3 revealed four compounds with notable activity, three of which exhibited IC₅₀ values below 1 µM, while none displayed significant cytotoxicity at 10 µM. Full article

(This article belongs to the Section Medicinal Chemistry)

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14 pages, 2013 KB

Open AccessArticle

Anti-Invasive and Apoptotic Effect of Eupatilin on YD-10B Human Oral Squamous Carcinoma Cells

by Gaeun Kim, Hyun-Jung Park, Suk-Yul Jung and Eun-Jung Kim

Molecules 2025, 30(24), 4666; https://doi.org/10.3390/molecules30244666 - 5 Dec 2025

Abstract

Oral squamous cell carcinoma (OSCC) is an aggressive malignancy characterized by high invasiveness and poor prognosis. This study investigated the anticancer mechanisms of eupatilin, a pharmacologically active flavonoid derived from Artemisia species, in human OSCC YD-10B cells. Eupatilin significantly reduced cell viability in [...] Read more.

Oral squamous cell carcinoma (OSCC) is an aggressive malignancy characterized by high invasiveness and poor prognosis. This study investigated the anticancer mechanisms of eupatilin, a pharmacologically active flavonoid derived from Artemisia species, in human OSCC YD-10B cells. Eupatilin significantly reduced cell viability in a dose-dependent manner, with an IC₅₀ of approximately 50 μM. Flow cytometric analysis revealed G0/G1 phase arrest accompanied by downregulation of Cyclin D1 and CDK2, and upregulation of p21. Annexin V/Propidium Iodide staining and Western blotting confirmed apoptosis induction through activation of Bax, cleaved caspase-3/9, and poly ADP-ribose polymerase (PARP) cleavage, alongside suppression of Bcl-2. Furthermore, eupatilin markedly decreased both the mRNA expression and enzymatic activities of matrix metalloproteinases (MMP)-2 and MMP-9, indicating its potential to inhibit cancer cell invasion. Collectively, these findings demonstrate that eupatilin exerts potent antiproliferative and anti-invasive effects on OSCC cells via cell-cycle modulation and mitochondrial-mediated apoptosis. This study provides the first evidence of eupatilin’s therapeutic potential against OSCC, suggesting its promise as a natural compound for the development of safer and more effective treatments for oral cancer. Full article

(This article belongs to the Section Natural Products Chemistry)

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18 pages, 418 KB

Open AccessArticle

Profile of Free and Conjugated Phenolic Compounds of Okra Pods Subjected to High-Humidity Hot-Air Impingement Blanching (HHAIB)

by Danuta Zielińska, Natalia Płatosz, Kacper Górski, Magdalena Zielińska, Hong-Wei Xiao and Henryk Zieliński

Molecules 2025, 30(24), 4665; https://doi.org/10.3390/molecules30244665 - 5 Dec 2025

Abstract

The profiles of free, ester-bound, and glycoside-bound phenolic compounds in okra pods (OP) subjected to high-humidity hot-air impingement blanching (HHAIB) for up to 120 s were analyzed using a micro-HPLC-QTRAP/MS/MS method. Fourteen phenolic acids and ten flavonoids were identified in both unprocessed and [...] Read more.

The profiles of free, ester-bound, and glycoside-bound phenolic compounds in okra pods (OP) subjected to high-humidity hot-air impingement blanching (HHAIB) for up to 120 s were analyzed using a micro-HPLC-QTRAP/MS/MS method. Fourteen phenolic acids and ten flavonoids were identified in both unprocessed and HHAIB-treated samples. Phenolic acids and flavonoids were mainly present in free and ester-bound forms. HHAIB treatment up to 60 s resulted in a progressive decrease in the contents of free, ester-bound, and glycoside-bound phenolic acids. In contrast, the content of free flavonoids initially increased after 5 s of HHAIB, followed by a gradual decrease in conjugated forms with prolonged treatment. The results indicate that blanching for 90 s ensured the highest partial recovery of free and conjugated phenolic acids after initial loss as compared to the non-treated material. These findings demonstrate that HHAIB treatment can effectively modulate the phenolic composition of okra pods and help identify optimal processing conditions for maximizing the retention of bioactive compounds. Full article

(This article belongs to the Special Issue Research on Chemical Composition and Activity of Natural Products, 2nd Edition)

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2 pages, 135 KB

Open AccessRetraction

RETRACTED: Chae et al. Anticancer Activity of 2-O-Caffeoyl Alphitolic Acid Extracted from the Lichen, Usnea barbata 2017-KL-10. Molecules 2021, 26, 3937

by Hae-Jung Chae, Geum-Jin Kim, Barsha Deshar, Hyun-Jin Kim, Min-Ji Shin, Hyukbean Kwon, Ui-Joung Youn, Joo-Won Nam, Sung-Hak Kim, Hyukjae Choi and Sung-Suk Suh

Molecules 2025, 30(24), 4664; https://doi.org/10.3390/molecules30244664 - 5 Dec 2025

Abstract

The journal retracts the article titled “Anticancer Activity of 2-O-Caffeoyl Alphitolic Acid Extracted from the Lichen, Usnea barbata 2017-KL-10” [...] Full article

10 pages, 343 KB

Open AccessArticle

Quantum Smell: Tunneling Mechanisms in Olfaction

by Dominik Szczȩśniak, Ewa A. Drzazga-Szczȩśniak, Adam Z. Kaczmarek and Sabre Kais

Molecules 2025, 30(24), 4663; https://doi.org/10.3390/molecules30244663 - 5 Dec 2025

Abstract

The mechanism by which odorants are recognized by olfactory receptors remains primarily unresolved. While charge transport is believed to play a significant role, its precise nature is still unclear. Here, we present a novel perspective by exploring the interplay between the intrinsic energy [...] Read more.

The mechanism by which odorants are recognized by olfactory receptors remains primarily unresolved. While charge transport is believed to play a significant role, its precise nature is still unclear. Here, we present a novel perspective by exploring the interplay between the intrinsic energy scales of odorant molecules and the gap states that facilitate intermolecular charge transport. We find that odorants act as weak tunneling conductors mainly because of the limited magnitude of electronic coupling between frontier molecular levels. This behavior is further connected to electron–phonon interaction and reorganization energy, suggesting that physically meaningful values for the latter parameter emerge only in the deep off-resonant tunneling regime. These findings complement the swipe card model of olfaction, in which an odorant needs both the right shape to bind to a receptor and the correct vibrational frequency to trigger signal transduction. Moreover, they reveal that the underlying mechanisms are much more complex than previously assumed. Full article

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28 pages, 7110 KB

Open AccessArticle

New Dimethylpyridine-3-Carboxamide Derivatives as MMP-13 Inhibitors with Anticancer Activity

by Remigiusz Płaczek, Tomasz Janek, Małgorzata Strzelecka, Aleksandra Kotynia, Piotr Świątek and Żaneta Czyżnikowska

Molecules 2025, 30(24), 4662; https://doi.org/10.3390/molecules30244662 - 5 Dec 2025

Abstract

A series of dimethylpyridine-3-carboxamide derivatives was designed as potential, selective, non-zinc chelating inhibitors of matrix metalloproteinase 13 (MMP-13), and subsequently synthesized. The identity of the obtained compounds was confirmed by FT-IR, ¹H/¹³C NMR, and HR-MS methods. Fluorescence spectroscopy was applied [...] Read more.

A series of dimethylpyridine-3-carboxamide derivatives was designed as potential, selective, non-zinc chelating inhibitors of matrix metalloproteinase 13 (MMP-13), and subsequently synthesized. The identity of the obtained compounds was confirmed by FT-IR, ¹H/¹³C NMR, and HR-MS methods. Fluorescence spectroscopy was applied to study the interaction of synthesized compounds with human serum albumin, providing insight into their potential transport properties in plasma. In parallel, the electronic properties and reactivity parameters relevant to enzyme binding of the designed molecules were analyzed using density functional theory. Molecular docking and molecular dynamics simulations revealed the compounds to interact preferentially and stably within the S₁ pocket of MMP-13 via hydrogen bonds and π-stacking interactions. The calculated binding free energy confirmed the stability and persistence of the complexes during simulation, indicating a strong and specific recognition pattern. On the other hand, their affinity towards MMP-8 was considerably weaker, which is consistent with the predicted selectivity profile. In addition, the biological evaluation confirmed MMP-13 inhibition. Finally, in vitro tests revealed their cytotoxic activity against cancer cell lines. Full article

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

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19 pages, 4093 KB

Open AccessArticle

Computational Study of Graphene Quantum Dots (GQDs) Functionalized with Thiol and Amino Groups for the Selective Detection of Heavy Metals in Wastewater

by Joaquín Alejandro Hernández-Fernández, Juan Sebastian Gómez Pérez and Edgar Marquez

Molecules 2025, 30(24), 4661; https://doi.org/10.3390/molecules30244661 - 5 Dec 2025

Abstract

Given the growing interest in contaminant detection, research has addressed the functionalization behavior of graphene quantum dots (GQDs) with thiol (-SH) and amino (-NH₂) groups to optimize and improve the selective detection of heavy metals in wastewater. Implementing Density Functional Theory [...] Read more.

Given the growing interest in contaminant detection, research has addressed the functionalization behavior of graphene quantum dots (GQDs) with thiol (-SH) and amino (-NH₂) groups to optimize and improve the selective detection of heavy metals in wastewater. Implementing Density Functional Theory (DFT), the interactions between the functionalized GQDs and hydrated metals such as Cr, Cd, and Pb were simulated. The results showed that GQDs with thiol groups exhibited a high affinity for metals such as Pb and Cd, with an energy gap (Eg) of 0.02175 eV in the interaction with Pb, showing optimized reactivity. On the other hand, amino-modified GQDs presented a higher Eg, indicating a lower reactivity and efficacy in contaminant identification. Furthermore, this study evaluated electronic properties such as the energy gap and total dipole moment (TDM), resulting in the -SH-functionalized GQDs showing a higher TDM, which presented a greater interaction capacity with these metals. Likewise, the electrostatic potential maps (MEPs) provided information on the charge distribution when adsorbing metals, an important parameter to understand electronic interactions. These results showed that the modification of GQDs improved the detection of heavy metals, although limitations in the DFT method used are recognized and the need for experimental studies is suggested to validate the results and investigate other functional modifications. Full article

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Molecules, Volume 30, Issue 24 (December-2 2025) – 23 articles

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