Molecules

13 pages, 3593 KiB

Open AccessArticle

Influence of Metal Composition and Support Material on Carbon Yield and Quality in the Direct Decomposition of Methane

by Uidam Jun, Bon-Jun Ku, Yeji Gwon, Dong-Hyun Kim, Mansu Kim, I-Jeong Jeon, Hongjin Lee, Jae-Oh Shim and Kyubock Lee

Molecules 2025, 30(9), 1903; https://doi.org/10.3390/molecules30091903 - 24 Apr 2025

Abstract

A series of catalysts were synthesized via a combination of evaporation-induced self-assembly and spray pyrolysis; they were then applied to the direct decomposition of methane. Among them, Ni-Cu/MgO catalysts exhibited the smallest Ni particle size (~9 nm), attributed to the Cu-induced suppression of [...] Read more.

A series of catalysts were synthesized via a combination of evaporation-induced self-assembly and spray pyrolysis; they were then applied to the direct decomposition of methane. Among them, Ni-Cu/MgO catalysts exhibited the smallest Ni particle size (~9 nm), attributed to the Cu-induced suppression of Ni crystal growth during synthesis. These catalysts achieved the highest carbon yield, primarily due to the enhanced dispersion and nanoscale size of Ni particles. The interaction between methane and the catalysts, as well as the structural and electrical properties of the resulting carbon nanotubes, such as crystallinity and conductivity, were investigated with respect to the support material (MgO vs. Al₂O₃) and metal composition (Ni vs. Ni-Cu). The findings provide valuable insights for designing advanced catalyst systems for the efficient conversion of methane into high-value carbon-based materials. Full article

(This article belongs to the Special Issue Research on Heterogeneous Catalysis—2nd Edition)

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20 pages, 2135 KiB

Open AccessArticle

Green Synthesis and Characterization of Fe-Ti Mixed Nanoparticles for Enhanced Lead Removal from Aqueous Solutions

by Shamika P. W. R. Hewage and Harshica Fernando

Molecules 2025, 30(9), 1902; https://doi.org/10.3390/molecules30091902 - 24 Apr 2025

Abstract

Heavy metal contamination in water resources presents a significant environmental and public health challenge, with lead being particularly concerning due to its toxicity and persistence. This study reports the green synthesis of Fe-Ti mixed oxide nanoparticles (NPs) using dextrose as a green source [...] Read more.

Heavy metal contamination in water resources presents a significant environmental and public health challenge, with lead being particularly concerning due to its toxicity and persistence. This study reports the green synthesis of Fe-Ti mixed oxide nanoparticles (NPs) using dextrose as a green source and investigates their effectiveness in lead removal from aqueous solutions. The synthesized NPs were characterized using XRD, FTIR, XPS, SEM-EDS, and BET analysis, revealing an amorphous structure with a high surface area (292.89 m² g⁻¹) and mesoporous characteristics. XPS analysis confirmed the presence of mixed Fe³⁺/Fe²⁺ valence states in a Ti⁴⁺-rich framework, creating diverse binding sites for lead adsorption. The material exhibited optimal lead removal at pH 5, with adsorption following pseudo-second-order kinetics (R² > 0.99) and a Langmuir isotherm model (R² > 0.98). Maximum adsorption capacity reached 25.10 mg g⁻¹ at 40 °C, showing endothermic behavior. The low point of zero charge (PZC, 0.22) and surface hydroxyl groups enabled efficient lead binding possibly through multiple mechanisms. Dose optimization studies established 6 g L⁻¹ as the optimal adsorbent concentration. The synergistic combination of iron’s affinity for heavy metals and titanium’s structural stability, coupled with environmentally friendly synthesis, resulted in a promising material for sustainable water treatment applications. Full article

(This article belongs to the Special Issue Advances in Homogeneous/Heterogeneous Photocatalysis to the Degradation of Pollutants in Water)

20 pages, 2160 KiB

Open AccessArticle

Conformational Locking of the Geometry in Photoluminescent Cyclometalated N^C^N Ni(II) Complexes

by Maryam Niazi, Iván Maisuls, Lukas A. Mai, Sascha A. Schäfer, Alex Oster, Lukas S. Diaz, Dirk M. Guldi, Nikos L. Doltsinis, Cristian A. Strassert and Axel Klein

Molecules 2025, 30(9), 1901; https://doi.org/10.3390/molecules30091901 - 24 Apr 2025

Abstract

In our research aimed at replacing precious transition metals like platinum with abundant base metals such as nickel for efficient triplet emitters, we synthesized and studied Ni(II) complexes [Ni(L^NHR)Cl]. These complexes containing the N^C^N cyclometalating dipyridyl-phenide ligand, equipped with pending H-bonding [...] Read more.

In our research aimed at replacing precious transition metals like platinum with abundant base metals such as nickel for efficient triplet emitters, we synthesized and studied Ni(II) complexes [Ni(L^NHR)Cl]. These complexes containing the N^C^N cyclometalating dipyridyl-phenide ligand, equipped with pending H-bonding amine groups (NH(C₆H₅) (L^NHPh) and NH(C₆H₅CH₂), ClL^NHBn). Molecular structures determined from experimental X-ray diffractometry and density functional theory (DFT) calculations in the ground state showed marked deviation of the Cl⁻ coligand (ancillary ligand) from the ideal planar coordination, with τ₄ values of 0.35 and 0.33, respectively, along with hydrogen bonding interactions of the ligand NH function with the Cl⁻ coligand. The complexes exhibit long-wavelength absorption bands at approximately 425 nm in solution, with the experimental spectra being accurately reproduced through time-dependent density functional theory (TD-DFT) calculations. Vibrationally structured emission profiles and steady-state photoluminescence quantum yields of 30% for [Ni(L^NHPh)Cl] and 40% for [Ni(L^NHBn)Cl] (along with dual excited state lifetimes in the ns and in the ms range) were found in frozen 2-methyl-tetrahydrofuran (2MeTHF) glassy matrices at 77 K. Furthermore, within a poly(methyl methacrylate) matrix, the complexes showed emission bands centered at around 550 nm within a temperature range from 6 K to 300 K with lifetimes similar to 77 K. Based on TD-DFT potential scans along the metal–ligand (Ni–N) coordinate, we found that in a rigid environment that restricts the geometry to the Franck-Condon region, either the triplet T₅ or the singlet S₄ state could contribute to the photoluminescence. Full article

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

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20 pages, 1442 KiB

Open AccessArticle

Liquid Chromatography-Tandem Mass Spectrometry Method Development and Validation for the Determination of a New Mitochondrial Antioxidant in Mouse Liver and Cerebellum, Employing Advanced Chemometrics

by Anthi Panara, Dimitra Biliraki, Markus Nussbaumer, Michaela D. Filiou, Nikolaos S. Thomaidis, Ioannis K. Kostakis and Evagelos Gikas

Molecules 2025, 30(9), 1900; https://doi.org/10.3390/molecules30091900 - 24 Apr 2025

Abstract

Anxiety and stress-related disorders affect all ages in all geographical areas. As high anxiety and chronic stress result in the modulation of mitochondrial pathways, intensive research is being carried out on pharmaceutical interventions that alleviate pertinent symptomatology. Therefore, innovative approaches being currently pursued [...] Read more.

Anxiety and stress-related disorders affect all ages in all geographical areas. As high anxiety and chronic stress result in the modulation of mitochondrial pathways, intensive research is being carried out on pharmaceutical interventions that alleviate pertinent symptomatology. Therefore, innovative approaches being currently pursued include substances that target mitochondria bearing an antioxidant moiety. In this study, a newly synthesized antioxidant consisting of triphenylphosphine (TPP), a six-carbon alkyl spacer, and hydroxytyrosol (HT) was administered orally to mice via drinking water. Cerebellum and liver samples were collected and analyzed using ultra-high-performance liquid chromatography-tandem triple quadrupole mass spectrometry (UHPLC-MS/MS) to assess the levels of TPP-HT in the respective tissues to evaluate in vivo administration efficacy. Sample preparation included extraction with appropriate solvents and a preconcentration step to achieve the required sensitivity. Both methods were validated in terms of selectivity, linearity, accuracy, and limits of detection and quantification. Αdditionally, a workflow for evaluating and statistically summarizing multiple fortified calibration curves was devised. TPP-HT penetrates the blood–brain barrier (BBB), with a level of 11.5 ng g⁻¹ quantified in the cerebellum, whereas a level of 4.8 ng g⁻¹ was detected in the liver, highlighting the plausibility of orally administering TPP-HT to achieve mitochondrial targeting. Full article

(This article belongs to the Special Issue The 30th Anniversary of Molecules—Recent Advances in Chemical Biology)

24 pages, 1233 KiB

Open AccessReview

CD44 Variant Expression in Follicular Cell-Derived Thyroid Cancers: Implications for Overcoming Multidrug Resistance

by Benny Mosoane, Michelle McCabe, Brandon S. Jackson and Zodwa Dlamini

Molecules 2025, 30(9), 1899; https://doi.org/10.3390/molecules30091899 - 24 Apr 2025

Abstract

Thyroid cancer (TC) is a significant global health issue that exhibits notable heterogeneity in incidence and outcomes. In low-resource settings such as Africa, delayed diagnosis and limited healthcare access exacerbate mortality rates. Among follicular cell-derived thyroid cancers—including papillary (PTC), follicular (FTC), anaplastic (ATC), [...] Read more.

Thyroid cancer (TC) is a significant global health issue that exhibits notable heterogeneity in incidence and outcomes. In low-resource settings such as Africa, delayed diagnosis and limited healthcare access exacerbate mortality rates. Among follicular cell-derived thyroid cancers—including papillary (PTC), follicular (FTC), anaplastic (ATC), and poorly differentiated (PDTC) subtypes—the role of CD44 variants has emerged as a critical factor influencing tumor progression and multidrug resistance (MDR). CD44, a transmembrane glycoprotein, and its splice variants (CD44v) mediate cell adhesion, migration, and survival, contributing to cancer stem cell (CSC) maintenance and therapy resistance. Differential expression patterns of CD44 isoforms across TC subtypes have shown diagnostic, prognostic, and therapeutic implications. Specifically, CD44v6 expression in PTC has been correlated with metastasis and aggressive tumor behavior, while in FTC, its expression aids in distinguishing malignant from benign lesions. Furthermore, CD44 contributes to MDR through enhanced drug efflux via ABC transporters, apoptosis evasion, and CSC maintenance via the Wnt/β-catenin and PI3K/Akt pathways. Targeted therapies against CD44 such as monoclonal antibodies, hyaluronic acid-based nanocarriers, and gene-editing technologies hold promise in overcoming MDR. However, despite the mounting evidence supporting CD44-targeted strategies in various cancers, research on this therapeutic potential in TC remains limited. This review synthesizes existing knowledge on CD44 variant expression in follicular cell-derived thyroid cancers and highlights potential therapeutic strategies to mitigate MDR, particularly in high-burden regions, thereby improving patient outcomes and survival. Full article

(This article belongs to the Special Issue New Therapeutic Tools against MDR Tumors: Discovery, Synthesis and Evaluation of Bioactive Compounds)

17 pages, 3911 KiB

Open AccessArticle

Wood-Based Micro-Biochars in a Cement Mixture

by Minkyeong Pyo, Jongsun Kim, Seungwook Seok, Chan Ho Park and Wonchang Choi

Molecules 2025, 30(9), 1898; https://doi.org/10.3390/molecules30091898 - 24 Apr 2025

Abstract

Immediate action is required to achieve carbon neutrality within the cement industry. The integration of biochar into cement as a component of reinforced concrete has potential to mitigate carbon emissions in the construction sector by enabling carbon sequestration. In pursuit of eco-friendly practices [...] Read more.

Immediate action is required to achieve carbon neutrality within the cement industry. The integration of biochar into cement as a component of reinforced concrete has potential to mitigate carbon emissions in the construction sector by enabling carbon sequestration. In pursuit of eco-friendly practices and improved physical properties of cement composites, this study investigated the properties of wood-based, micron-sized biochar as a non-carbonate raw material, including its chemical composition, morphology, and wettability. The characterization of lignocellulosic micro-biochar and its mechanical impact on cement composites was a focus of this study. Cement was partially replaced with varying weight percentages of micro-biochar (1, 3, and 5 wt%), and the effects were evaluated through compressive strength tests after 7 and 28 d. The results demonstrated that the micro-biochar could sustain strength even when substituted for cement. Notably, after 28 d, the compressive strength of the sample with only cement was 29.6 MPa, while the sample with 3 wt% biochar substitution showed 30.9 MPa, indicating a 4.4% increase. This research contributes to sustainable construction practices by offering a green solution for reducing carbon emissions in the industry. Full article

(This article belongs to the Special Issue Carbon-Based Materials for Sustainable Chemistry: 2nd Edition)

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37 pages, 8170 KiB

Open AccessArticle

Drug Repurposing to Inhibit Oncostatin M in Crohn’s Disease

by Faranak Bahramimehr, Axel Guthart, Stefanie Kurz, Yuanping Hai, Mona Dawood, Rümeysa Yücer, Nasim Shahhamzehei, Ralf Weiskirchen, Wilfried Roth, Wolfgang Stremmel, Gerhard Bringmann and Thomas Efferth

Molecules 2025, 30(9), 1897; https://doi.org/10.3390/molecules30091897 - 24 Apr 2025

Abstract

Crohn’s disease is an inflammatory bowel disease (IBD) that currently lacks satisfactory treatment options. Therefore, new targets for new drugs are urgently needed to combat this disease. In the present study, we investigated the transcriptomics-based mRNA expression of intestinal biopsies from patients with [...] Read more.

Crohn’s disease is an inflammatory bowel disease (IBD) that currently lacks satisfactory treatment options. Therefore, new targets for new drugs are urgently needed to combat this disease. In the present study, we investigated the transcriptomics-based mRNA expression of intestinal biopsies from patients with Crohn’s disease. We compared the mRNA expression profiles of the ileum and colon of patients with those of healthy individuals. A total of 72 genes in the ileum and 33 genes in the colon were differentially regulated. Among these, six genes were overexpressed in both tissues, including IL1B, TCL1A, HCAR3, IGHG1, S100AB, and OSM. We further focused on OSM/oncostatin M. To confirm the responsiveness of intestinal tissues from patients with Crohn’s disease to oncostatin M inhibition, we examined the expression of the oncostatin M receptor using immunohistochemistry in patient biopsies as well as in kindlin-1^−/− and kindlin-2^−/− knockout mice, which exhibit an inflammatory bowel disease (IBD) phenotype, and found strong oncostatin M expression in all samples examined. Next, we conducted a drug-repurposing study using the supercomputer MOGON and bioinformatic methods. A total of 13 candidate compounds out of 1577 FDA-approved drugs were identified by PyRx-based virtual drug screening and AutoDock-based molecular docking. Their lowest binding energies (LBEs) ranged from −10.46 (±0.08) to −8.77 (±0.08) kcal/mol, and their predicted inhibition constants (pK_i) ranged from 21.62 (±2.97) to 373.78 (±36.78) nM. Ecamsule has an interesting stereostructure with two C₂-symmetric enantiomers (1S,4R-1′S,4′R and 1R,4S-1′R,4′S) (1a and 1b) and one meso diastereomer (1S,4R-1′R,4′S) (1c). These three stereoisomers showed strong, albeit differing, binding affinities in molecular docking. As examined by nuclear magnetic resonance and polarimetry, the 1S,4R-1′S,4′R isomer was the stereoisomer present in our commercially available preparations used for microscale thermophoresis. Ecamsule (1a) was chosen for in vitro validation using recombinant oncostatin M and microscale thermophoresis. Considerable dissociation constants were obtained for ecamsule after three repetitions with a K_d value of 11.36 ± 2.83 µM. Subsequently, we evaluated, by qRT-PCR, the efficacy of ecamsule (1a) as a potential drug that could prevent oncostatin M activation by inhibiting downstream inflammatory marker genes (IL6, TNFA, and CXCL11). In conclusion, we have identified oncostatin M as a promising new drug target for Crohn’s disease through transcriptomics and ecamsule as a potential new drug candidate for Crohn’s disease through a drug-repurposing approach both in silico and in vitro. Full article

(This article belongs to the Special Issue Bioorganic Chemistry in Europe)

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21 pages, 9966 KiB

Open AccessArticle

Optimization of Zinc and Aluminum Hydroxyquinolines for Applications as Semiconductors in Molecular Electronics

by María Elena Sánchez Vergara, Francisco Iñaki Díaz Morales, Bertha Molina, Edgar Alvarez-Zauco, Lourdes Bazán-Díaz and Roberto Salcedo

Molecules 2025, 30(9), 1896; https://doi.org/10.3390/molecules30091896 - 24 Apr 2025

Abstract

This work explores the dispersed heterojunction of tris-(8-hydroxyquinoline) aluminum (AlQ₃) and 8-hydroxyquinoline zinc (ZnQ₂) with tetracyanoquinodimethane (TCNQ) and 2,6-diaminoanthraquinone (DAAq). Thin films of these organic semiconductors were deposited and analyzed, with their structures calculated with the B3PW91/6-31G** method. The [...] Read more.

This work explores the dispersed heterojunction of tris-(8-hydroxyquinoline) aluminum (AlQ₃) and 8-hydroxyquinoline zinc (ZnQ₂) with tetracyanoquinodimethane (TCNQ) and 2,6-diaminoanthraquinone (DAAq). Thin films of these organic semiconductors were deposited and analyzed, with their structures calculated with the B3PW91/6-31G** method. The optimized structure for AlQ₃-TCNQ, AlQ₃-DAAq, is achieved by means of three hydrogen bonds, whereas for ZnQ₂-DAAq, two hydrogen interactions are predicted. These structures were recalculated including the GD3 dispersion term. A stable ordering was also achieved for AlQ₃-TCNQ-GD3, AlQ₃-DAAq-GD3, and ZnQ₂-DAAq-GD3 with four and two hydrogen contacts for the former and the two latter, respectively. Infrared (IR) and UV-visible spectroscopy confirmed these theoretical predictions, in addition to obtaining the optical band gap for the films. The optical band gap values ranged between 1.62 and 2.97 eV (theoretical) and between 2.46 and 2.87 eV (experimental). Additional optical parameters and electrical behavior were obtained, which indicates the potential of the films to be used as organic semiconductors. All three films showed transmittance above 76%, which also broadens the range of applications in electrodes, transparent transistors, or photovoltaic cells. Devices fabricated using these materials displayed ohmic electrical behavior, with peak current values between 2 × 10⁻³ and 6 × 10⁻³ A. Full article

(This article belongs to the Special Issue Recent Advancements in Semiconductor Materials)

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27 pages, 3118 KiB

Open AccessReview

Implications of Mucin-Type O-Glycosylation in Alzheimer’s Disease

by Nancy Vela Navarro, Gustavo De Nadai Mundim and Maré Cudic

Molecules 2025, 30(9), 1895; https://doi.org/10.3390/molecules30091895 - 24 Apr 2025

Abstract

Alzheimer’s disease (AD) is one of the most common neurodegenerative disorders linked to aging. Major hallmarks of AD pathogenesis include amyloid-β peptide (Aβ) plaques, which are extracellular deposits originating from the processing of the amyloid precursor protein (APP), and neurofibrillary tangles (NFTs), which [...] Read more.

Alzheimer’s disease (AD) is one of the most common neurodegenerative disorders linked to aging. Major hallmarks of AD pathogenesis include amyloid-β peptide (Aβ) plaques, which are extracellular deposits originating from the processing of the amyloid precursor protein (APP), and neurofibrillary tangles (NFTs), which are intracellular aggregates of tau protein. Recent evidence indicates that disruptions in metal homeostasis and impaired immune recognition of these aggregates trigger neuroinflammation, ultimately driving disease progression. Therefore, a more comprehensive approach is needed to understand the underlying causes of the disease. Patients with AD present abnormal glycan profiles, and most known AD-related molecules are either modified with glycans or involved in glycan regulation. A deeper understanding of how O-glycosylation influences the balance between amyloid-beta peptide production and clearance, as well as microglia’s pro- and anti-inflammatory responses, is crucial for deciphering the early pathogenic events of AD. This review aims to provide a comprehensive summary of the extensive research conducted on the role of mucin-type O-glycosylation in the pathogenesis of AD, discussing its role in disease onset and immune recognition. Full article

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16 pages, 970 KiB

Open AccessArticle

Green Analytical Method Using Single-Drop Microextraction Followed by Gas Chromatography for Nitro Compound Detection in Environmental Water and Forensic Rinse Water

by Tamara Pócsová, Senad Okanovič and Svetlana Hrouzková

Molecules 2025, 30(9), 1894; https://doi.org/10.3390/molecules30091894 - 24 Apr 2025

Abstract

The extensive use of nitro compounds in agriculture, industry, armaments, and pharmaceuticals, along with their toxic effects on living organisms, necessitates efficient and environmentally sustainable analytical methods. Traditional extraction techniques often involve practices that are not eco-friendly, such as the use of large [...] Read more.

The extensive use of nitro compounds in agriculture, industry, armaments, and pharmaceuticals, along with their toxic effects on living organisms, necessitates efficient and environmentally sustainable analytical methods. Traditional extraction techniques often involve practices that are not eco-friendly, such as the use of large volumes of solvents, toxic chemicals, and the generation of significant waste; therefore, the single-drop microextraction technique was involved in overcoming these limitations. This study shows an environmentally friendly method for nitro compound analysis focusing on NB (Nitrobenzene), 2-NT (2-Nitrotoluene), 3-NT (3-Nitrotoluene), 4-NT (4-Nitrotoluene), 1,3-DNB (1,3-Dinitrobenzene), 1,2-DNB (1,2-Dinitrobenzene), 2,4-DNT (2,4-Dinitrotoluene), and TNT (Trinitrotoluene). To separate and to detect selected nitro compounds, gas chromatography with an electron capture detector was utilized, which is highly selective for analytes containing nitro groups. To determine optimal experimental conditions, extraction parameters were studied, including the impact of salt addition, temperature, and pH on extraction efficiency. Key performance parameters, such as limit of detection (LOD), limit of quantification (LOQ), repeatability, extraction recoveries, calibration range, and matrix effects, were assessed. The LOD values ranged from 0.01 to 0.09 μg/L in deionized water, 0.01 to 0.06 μg/L in tap water, 0.01 to 0.03 μg/L in seawater, and 0.03 to 0.11 μg/L in model forensic rinse water. The optimized method was successfully applied to the determination of nitro compounds in real environmental water samples and forensic rinse water samples. The environmental sustainability and greenness of the proposed method was evaluated with the AGREE, AGREEprep, and AESA techniques. Full article

(This article belongs to the Special Issue Analytical Methods for Food and Environmental Pollutants: Current and Future Perspectives)

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29 pages, 7203 KiB

Open AccessArticle

New Cu(II), Cu(I) and Ag(I) Complexes of Phenoxy-Ketimine Schiff Base Ligands: Synthesis, Structures and Antibacterial Activity

by Miriam Caviglia, Zhenzhen Li, Carlo Santini, Jo’ Del Gobbo, Cristina Cimarelli, Miao Du, Alessandro Dolmella and Maura Pellei

Molecules 2025, 30(9), 1893; https://doi.org/10.3390/molecules30091893 - 24 Apr 2025

Abstract

Two phenoxy-ketimines ligands, 2-(1-(benzylimino)ethyl)phenol (HL^BSMe) and 2-((benzylimino)(phenyl)methyl)phenol (HL^BSPh), were synthesized and used as supporting ligands of new copper(II), copper(I), and silver(I) complexes. In order to confer different solubility properties to the metal complexes and to stabilize Cu and Ag [...] Read more.

Two phenoxy-ketimines ligands, 2-(1-(benzylimino)ethyl)phenol (HL^BSMe) and 2-((benzylimino)(phenyl)methyl)phenol (HL^BSPh), were synthesized and used as supporting ligands of new copper(II), copper(I), and silver(I) complexes. In order to confer different solubility properties to the metal complexes and to stabilize Cu and Ag in their +1 oxidation state, the lipophilic triphenylphosphine (PPh₃) and the hydrophilic 1,3,5-triaza-7-phosphaadamantane (PTA) were selected as co-ligands in the syntheses of the Cu(I) and Ag(I) complexes. All compounds were characterized by CHN analysis, NMR, FT-IR spectroscopy, and electrospray ionization mass spectrometry (ESI-MS); the molecular structure of the copper(II) complex [Cu(L^BSPh)₂] was also determined by single-crystal X-ray diffraction. Finally, the antibacterial activity of the metal complexes, the Schiff base ligands and phosphane co-ligands, were assessed by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Gram-negative (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus). Full article

(This article belongs to the Topic Metal Ions in Health and Diseases: Current Progress and Future Challenges)

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20 pages, 6359 KiB

Open AccessArticle

Antioxidant and Anti-Inflammatory Activities of Astilboides tabularis (Hemsl.) Engl. Root Extract

by Nam Ho Yoo, Young Sun Baek, Hee Kyu Kim, Chan Ok Lee and Myong Jo Kim

Molecules 2025, 30(9), 1892; https://doi.org/10.3390/molecules30091892 - 24 Apr 2025

Abstract

Here, we examined the antioxidant and anti-inflammatory activities of the ethyl acetate (EtOAc) fraction of Astilboides tabularis (Hemsl.) Engl. root extracts, initially prepared from a 70% ethanol extraction. This EtOAc fraction exhibited significant scavenging activity against DPPH radicals (IC₅₀: 11.38 ± [...] Read more.

Here, we examined the antioxidant and anti-inflammatory activities of the ethyl acetate (EtOAc) fraction of Astilboides tabularis (Hemsl.) Engl. root extracts, initially prepared from a 70% ethanol extraction. This EtOAc fraction exhibited significant scavenging activity against DPPH radicals (IC₅₀: 11.38 ± 0.48 µg/mL) and ABTS radicals (IC₅₀: 7.46 ± 0.58 µg/mL), and had a high total phenolic content (i.e., 407.02 ± 13.56 mg GAE/g). In addition, the EtOAc fraction demonstrated concentration-dependent protective effects in a RAW264.7 macrophage cell model subjected to oxidative stress. In lipopolysaccharide (LPS)-stimulated RAW264.7 cells, nitric oxide (NO) production and the expression of inflammatory mediators (iNOS, COX-2, TNF-α, IL-1β, IFN-β) were inhibited in a concentration-dependent manner. Western blot and real-time PCR (RT-PCR) analyses revealed that the EtOAc fraction also suppressed inflammatory mediator expression via inhibiting the activation of the NF-κB and MAPK signaling pathways. Finally, LC-QTOF-MS and LC-MS/MS analyses identified gallic acid and bergenin as compounds contributing to observed antioxidant and anti-inflammatory effects. In conclusion, the EtOAc fraction of A. tabularis root extracts exhibited strong anti-oxidant and anti-inflammatory properties, suggesting potential usage for treating various inflammatory diseases. Full article

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33 pages, 3639 KiB

Open AccessReview

“Pepper”: Different Spices, One Name—Analysis of Sensory and Biological Aspects

by Pierina Díaz-Guerrero, Sofia Panzani, Chiara Sanmartin, Chiara Muntoni, Isabella Taglieri and Francesca Venturi

Molecules 2025, 30(9), 1891; https://doi.org/10.3390/molecules30091891 - 24 Apr 2025

Abstract

Spices are a part of modern and ancient cultures due to their recognized culinary and medicinal properties. Pepper is commonly used in many recipes; however, in the field of gastronomy, the term “pepper” usually refers to a group that includes several different spices, [...] Read more.

Spices are a part of modern and ancient cultures due to their recognized culinary and medicinal properties. Pepper is commonly used in many recipes; however, in the field of gastronomy, the term “pepper” usually refers to a group that includes several different spices, such as black pepper (Piper nigrum L.), cubeb pepper (Piper cubeba L.f.), long pepper (Piper longum L.), pink pepper (Schinus terebinthifolius Raddi), allspice (Pimenta dioica L. Merrill), and Japanese pepper (Zanthoxylum piperitum DC.). Despite the extensive study of the chemical characterization and medicinal and culinary properties of “pepper”, sensory analysis (color, aroma profile, odor profile, and chemesthesis) of these spices have not been completed. Therefore, the aim of this review was to identify the strengths, weaknesses, opportunities, and threats within the spice supply chain considering these six “peppers” to analyze their positive and negative aspects. Finally, we selected the most representative molecules and properties of spices referred to as “pepper” to expand the research focus and highlight their key aspects related to health and sensory science for future applications. In this sense, this review provides a new strategic guideline that will help us understand and assess the key internal and external factors of pepper, allowing them to be applied in different sectors with different approaches. Full article

(This article belongs to the Special Issue Nutrition and Sensory Analysis of Food)

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21 pages, 3065 KiB

Open AccessArticle

Reactive Behaviour of Platinum(II) Salts with Ethylenediamine in Sustainable Water/Choline Chloride-Based Deep Eutectic Solvents Mixtures

by Nicola Garofalo, Francesco Messa, Alessandra Barbanente, Francesco Paolo Fanizzi, Antonio Salomone, Nicola Margiotta and Paride Papadia

Molecules 2025, 30(9), 1890; https://doi.org/10.3390/molecules30091890 - 24 Apr 2025

Abstract

Deep eutectic solvents (DESs) are environmentally friendly solvents formed by combining hydrogen bond donors and acceptors, resulting in a eutectic mixture with a lower melting point than the individual components. While there is extensive research on the electrochemical synthesis of platinum nanoparticles in [...] Read more.

Deep eutectic solvents (DESs) are environmentally friendly solvents formed by combining hydrogen bond donors and acceptors, resulting in a eutectic mixture with a lower melting point than the individual components. While there is extensive research on the electrochemical synthesis of platinum nanoparticles in DESs, to the best of our knowledge, there are no studies on the chemical reactivity of platinum(II) complexes in these systems. This study investigates the simple model reaction between K₂PtCl₄ and ethylenediamine (en), exploring the behaviour in DES environment, to optimize the synthesis of simple cisplatin-like platinum compounds with the potential objective of improving the traditional methods, decreasing the number of steps required for obtaining target compounds and reducing chemical waste. The reactions were performed in two hydrophilic DESs: choline chloride:glycerol 1:2 (glyceline, GL) and choline chloride:ethylene glycol 1:2 (ethaline, EG). The experiments, conducted in a 70% (v/v) DES and 30% 1:1 H₂O/D₂O mixture to allow for direct NMR analysis, revealed that en quickly formed [PtCl₂(en)], which further reacted to produce [Pt(en)₂]Cl₂. Reaction products were characterised by 1D (¹H and ¹⁹⁵Pt{¹H}) and 2D ([¹H,¹³C]-HSQC and [¹H,¹⁵N]-HSQC) NMR experiments. The discolouration of solutions, due to the consumption of K₂PtCl₄, and the precipitation of the purple Magnus salt [Pt(en)₂][PtCl₄] occurred over time. The main observed difference between the two solvent mixtures was the slower reactivity in glyceline, due to the much higher viscosity of the solution. Diffusion-ordered spectroscopy (DOSY) indicated lower water mobility in DES mixtures than pure water, with the reaction products closely associated with DES molecules. Full article

(This article belongs to the Special Issue Applications of NMR Spectroscopy to Problem Solving for Inorganic, Organometallic, and Organic Compounds)

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13 pages, 4069 KiB

Open AccessArticle

Bioresorbable High-Strength HA/PLLA Composites for Internal Fracture Fixation

by Jie Liu, Mingtao Sun, Yipeng He, Weixia Yan, Muhuo Yu and Keqing Han

Molecules 2025, 30(9), 1889; https://doi.org/10.3390/molecules30091889 - 23 Apr 2025

Abstract

In modern surgery, the internal fixation plates fabricated from hydroxyapatite/poly(L-lactide) (HA/PLLA) composites encounter clinical limitations in fracture treatment due to their inadequate mechanical properties. In this work, pressure-induced flow (PIF) technique is employed to address this limitation. Under optimal processing conditions (140 °C [...] Read more.

In modern surgery, the internal fixation plates fabricated from hydroxyapatite/poly(L-lactide) (HA/PLLA) composites encounter clinical limitations in fracture treatment due to their inadequate mechanical properties. In this work, pressure-induced flow (PIF) technique is employed to address this limitation. Under optimal processing conditions (140 °C and 250 MPa), the HA/PLLA composites exhibit an impressive flexural strength of 199.2 MPa, which is comparable to that of human cortical bone, the strongest bone tissue in the body. The tensile strength and the notched Izod impact strength are close to 84.2 MPa and 16.7 kJ/m², respectively. Meanwhile, the HA/PLLA composites develop multi-level stacked crystal layers during PIF processing, accompanied by increases in crystallinity (53.1%), crystal orientation (81.6%) and glass transition temperature (78.8 °C). After 2 months of in vitro degradation, the HA/PLLA composites processed by the PIF technique still maintain considerable flexural strength (135.3 MPa). The excellent mechanical properties of HA/PLLA composites processed by PIF technique expand their potential as an internal fixation plate. Full article

(This article belongs to the Special Issue Molecular Scaffolds Design and Biomedical Applications)

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29 pages, 1843 KiB

Open AccessReview

Molecular Links Between Circadian Rhythm Disruption, Melatonin, and Neurodegenerative Diseases: An Updated Review

by Kemal Hüsnü Can Baser, Ismail Celil Haskologlu and Emine Erdag

Molecules 2025, 30(9), 1888; https://doi.org/10.3390/molecules30091888 - 23 Apr 2025

Abstract

Circadian rhythms are molecular oscillations governed by transcriptional–translational feedback loops (TTFLs) operating in nearly all cell types and are fundamental to physiological homeostasis. Key circadian regulators, such as circadian locomotor output cycles kaput (CLOCK), brain and muscle ARNT-like 1 (BMAL1), period [...] Read more.

Circadian rhythms are molecular oscillations governed by transcriptional–translational feedback loops (TTFLs) operating in nearly all cell types and are fundamental to physiological homeostasis. Key circadian regulators, such as circadian locomotor output cycles kaput (CLOCK), brain and muscle ARNT-like 1 (BMAL1), period (PER), and cryptochrome (CRY) gene families, regulate intracellular metabolism, oxidative balance, mitochondrial function, and synaptic plasticity. Circadian disruption is known as a central contributor to the molecular pathophysiology of neurodegenerative disorders. Disease-specific disruptions in clock gene expression and melatoninergic signaling are known as potential early-stage molecular biomarkers. Melatonin, a neurohormone secreted by the pineal gland, modulates clock gene expression, mitochondrial stability, and inflammatory responses. It also regulates epigenetic and metabolic processes through nuclear receptors and metabolic regulators involved in circadian and cellular stress pathways, thereby exerting neuroprotective effects and maintaining neuronal integrity. This review provides recent findings from the past five years, highlighting how circadian dysregulation mediates key molecular and cellular disturbances and the translational potential of circadian-based therapies in neurodegenerative diseases. Full article

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16 pages, 3975 KiB

Open AccessArticle

Perfluoropropionic Acid (CF₃CF₂C(O)OH): Three Conformations and Dimer Formation

by Carlos O. Della Védova, Rosana M. Romano, Hans-Georg Stammler and Norbert W. Mitzel

Molecules 2025, 30(9), 1887; https://doi.org/10.3390/molecules30091887 - 23 Apr 2025

Abstract

Perfluoropropionic acid (CF₃CF₂C(O)OH) has been investigated with a focus on its complex structural properties. As a formal derivative of propanoic acid, the incorporation of fluorine atoms imparts unique structural features, including three distinct monomeric conformations and a dimeric structure. [...] Read more.

Perfluoropropionic acid (CF₃CF₂C(O)OH) has been investigated with a focus on its complex structural properties. As a formal derivative of propanoic acid, the incorporation of fluorine atoms imparts unique structural features, including three distinct monomeric conformations and a dimeric structure. This study presents experimental findings, supported by computational modeling, to explore these characteristics. The analysis includes an FTIR study of the isolated species in an Ar-cryogenic matrix and the low-temperature determination of its crystalline structure using single-crystal X-ray diffraction. Full article

(This article belongs to the Special Issue From Spectroscopic Insights to Structural Wonders: A Theme Issue Dedicated to Professor Jaan Laane)

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15 pages, 1352 KiB

Open AccessArticle

Evaluation of Polycyclic Aromatic Hydrocarbons (PAHs) in Pork Meat Cooked with Two Different Methods

by Chiara Conchione, Silvia Socal, Laura Barp and Sabrina Moret

Molecules 2025, 30(9), 1886; https://doi.org/10.3390/molecules30091886 - 23 Apr 2025

Abstract

During domestic grilling, polycyclic aromatic hydrocarbons (PAHs), which include genotoxic and carcinogenic compounds, can be produced as a result of fat pyrolysis, leakage of cellular juices onto the heat source, and incomplete combustion of fuel. This study aimed to assess the formation of [...] Read more.

During domestic grilling, polycyclic aromatic hydrocarbons (PAHs), which include genotoxic and carcinogenic compounds, can be produced as a result of fat pyrolysis, leakage of cellular juices onto the heat source, and incomplete combustion of fuel. This study aimed to assess the formation of PAHs in pork neck cooked using two different grilling methods (traditional flat grill with beech charcoal and asado grill with beech wood flame) under controlled conditions, with cooking stopping at a core temperature of 72 °C. The impact of marinating and cooking speed (fast or slow) was also evaluated over three cooking sessions. After grilling, the meat samples underwent microwave-assisted extraction, purification through solid-phase extraction (SPE), and analysis using ultra-high-performance liquid chromatography (UHPLC) with spectrofluorometric detection. Statistical analysis was performed using ANOVA (R software, version 4.3.0). None of the samples exceeded the legal limits for benzo[a]pyrene (BaP) and PAH4 (sum of chrysene, benzo[a]anthracene, BaP, and benzo[b]fluoranthene). However, the asado grill showed a significantly higher average PAH contamination (1.21 µg/kg of BaP and 3.92 µg/kg of PAH4) compared with the traditional grill (0.22 µg/kg of BaP and 1.71 µg/kg of PAH4). Marinating and cooking speed did not have a significant impact on PAH levels. Full article

(This article belongs to the Special Issue Molecules in 2025)

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9 pages, 1045 KiB

Open AccessArticle

The Effects of Solvation Enthalpy, Surface Tension, and Conductivity of Common Additives on Positive Electrospray Ionization in Selected Pharmaceuticals

by Pieter Venter

Molecules 2025, 30(9), 1885; https://doi.org/10.3390/molecules30091885 - 23 Apr 2025

Abstract

This study investigates the effects of common additives, which provide distinct proton sources—ammonium (NH₄⁺) and hydronium (H₃O⁺)—along with their corresponding conjugate base species, on signal intensity in positive ionization mode. The findings reveal that signal intensity [...] Read more.

This study investigates the effects of common additives, which provide distinct proton sources—ammonium (NH₄⁺) and hydronium (H₃O⁺)—along with their corresponding conjugate base species, on signal intensity in positive ionization mode. The findings reveal that signal intensity is influenced by factors such as solvation enthalpy, surface tension, and conductivity. At lower additive concentrations (<10 mM), based on fold changes, no clear distinction could be made between formic acid, acetic acid, and their corresponding salts. At higher additive concentrations, NH₄⁺ appears to be a more efficient proton source than H⁺ (H₃O⁺), likely due to its more positive solvation enthalpy, which promotes greater enrichment of NH₄⁺ on the droplet surface, as well as the reduced surface tension of ammonium salts compared to their acid counterparts. Additionally, ammonium hydroxide proves to be the most effective ammonium-based modifier, likely due to its anionic conjugate base, hydroxide, which has a more negative solvation enthalpy compared to acetate and formate. This characteristic is hypothesized to reduce charge neutralization of cations on the droplet surface and/or in the gas phase. Furthermore, ammonium hydroxide exhibits lower conductivity compared to the other ammonium additives, which is believed to enhance signal intensity. Ammonium bicarbonate, the second most effective additive, uniquely prevents metal adduct formation, leading to enhanced [M + H]⁺ ion signals. Full article

(This article belongs to the Section Analytical Chemistry)

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