Molecules

14 pages, 4178 KB

Open AccessArticle

Improving Anti-Corrosion and Conductivity of NiTi Alloy Bipolar Plate Used for PEMFCs via Nb Alloying

by Ziyang Niu, Yingping Li, Yuanyuan Li, Xiaofen Wang, Yumin Pan, Zhuo He, Guohong Zhang, Zhen Wang and Qiongyu Zhou

Molecules 2025, 30(17), 3658; https://doi.org/10.3390/molecules30173658 - 8 Sep 2025

Viewed by 373

Abstract

NiTi alloy has emerged as a promising bipolar plate (BP) material for proton exchange membrane fuel cells (PEMFCs), combining Ti-like corrosion resistance with Ni-like electrical conductivity through its intermetallic characteristics. However, its performance faces greater challenges under aggressive operating conditions (70 °C, F [...] Read more.

NiTi alloy has emerged as a promising bipolar plate (BP) material for proton exchange membrane fuel cells (PEMFCs), combining Ti-like corrosion resistance with Ni-like electrical conductivity through its intermetallic characteristics. However, its performance faces greater challenges under aggressive operating conditions (70 °C, F⁻-containing acidic solution with air bubbling). This study demonstrates that Nb alloying effectively enhances NiTi while preserving its balanced properties. The developed NiTiNb alloy exhibits improved performance with 26% lower corrosion current density (i_c) and 29% reduced interfacial contact resistance (ICR) compared to conventional NiTi, effectively overcoming the conventional corrosion–conductivity trade-off in metallic BPs. The alloy also shows superior electrochemical stability and microhardness relative to pure Ti and Ni. These enhancements stem from a unique dual-phase microstructure comprising a NiTi (B2) matrix with continuous β-Nb grain boundary networks. During operation, this structure enables in situ formation of protective TiO₂-Nb₂O₅ films while maintaining conductive Nb/Nb₂O₅ pathways and metallic Ni domains. The findings establish Nb alloying as a viable optimization strategy for NiTi-based BP substrate in demanding PEMFC applications. Full article

(This article belongs to the Special Issue Electroanalysis of Biochemistry and Material Chemistry—2nd Edition)

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19 pages, 2275 KB

Open AccessArticle

The Impact of Proinflammatory M1 Macrophages on the Proliferation and Expression of Cyclin E2, Mitogen-Activated Protein Kinases 4 and 7 in Hepatocytes Isolated from a Diethylnitrosamine-Induced Hepatocellular Carcinoma Rat Model

by Marta Wójcik, Luisa Pozzo, Andrea Vornoli, Vincenzo Longo, Anna Śmiech, Joanna Czerwik-Marcinkowska, Iwona Rozempolska-Rucińska, Agnieszka Chrapko and Szymon Zmorzynski

Molecules 2025, 30(17), 3657; https://doi.org/10.3390/molecules30173657 - 8 Sep 2025

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Abstract

Background: Hepatocellular carcinoma (HCC) is highly resistant to conventional therapies, highlighting the need for novel immunotherapeutic approaches. In the tumor microenvironment (TME), the role of proinflammatory M1 macrophages remains ambiguous. The proteins Mapk4/7 and cyclin E2 (CE2, Ccne2) are crucial for regulating hepatocyte [...] Read more.

Background: Hepatocellular carcinoma (HCC) is highly resistant to conventional therapies, highlighting the need for novel immunotherapeutic approaches. In the tumor microenvironment (TME), the role of proinflammatory M1 macrophages remains ambiguous. The proteins Mapk4/7 and cyclin E2 (CE2, Ccne2) are crucial for regulating hepatocyte proliferation and may be important factors driving the development of HCC. This study aimed to investigate the effects of M1 macrophages on CE2 and Mapk4/7 expression, as well as hepatocyte proliferation, in a rat model of partial hepatectomy (PH) with or without diethylnitrosamine (DEN)-induced HCC. (2) Methods: Twenty female Wistar rats were assigned to nonneoplastic (PH) or neoplastic (PH/DEN) groups. Gene expression (CE2, Mapk4/7) was quantified via real-time PCR. (3) Results: Overexpression of CE2 and increased proliferation were observed in PH/DEN hepatocytes, whereas exposure to proinflammatory M1 macrophages significantly reduced their proliferative activity. Mapk4/7 expression patterns were modulated by the TME and significantly differ depending on macrophage activation status in both PH and PH/DEN-derived hepatocytes. (4) Conclusions: Our findings indicate that CE2 expression is upregulated in PH/DEN cells, with a notable decrease in the presence of M1 macrophages. In contrast, compared with control macrophages, M1 macrophages did not significantly affect Mapk4/7 expression. Full article

(This article belongs to the Section Chemical Biology)

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18 pages, 1285 KB

Open AccessReview

Advances in Pseudostellaria heterophylla Research: Current Status and Future Directions

by He Li, Shiying Wang, Zisong Yang and Pengda Ma

Molecules 2025, 30(17), 3656; https://doi.org/10.3390/molecules30173656 - 8 Sep 2025

Viewed by 326

Abstract

Pseudostellaria heterophylla, a dual-purpose medicinal and edible herb, has shown significant pharmacological potential, particularly through its immunomodulatory and antitumor activities. This review provides insights into the phytohormone regulatory mechanisms and active-component biosynthesis, highlighting key metabolic pathways and yield-optimization strategies. The interactions between [...] Read more.

Pseudostellaria heterophylla, a dual-purpose medicinal and edible herb, has shown significant pharmacological potential, particularly through its immunomodulatory and antitumor activities. This review provides insights into the phytohormone regulatory mechanisms and active-component biosynthesis, highlighting key metabolic pathways and yield-optimization strategies. The interactions between hormones and genes in root morphology and metabolite accumulation are discussed, offering new perspectives for molecular breeding. Additionally, a multidisciplinary framework is proposed to address cultivation challenges and quality enhancement, laying the groundwork for sustainable utilization of this valuable medicinal plant. Full article

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25 pages, 1535 KB

Open AccessReview

The Use of Crude Glycerol as a Co-Substrate for Anaerobic Digestion

by Wirginia Tomczak, Sławomir Żak, Anna Kujawska and Maciej Szwast

Molecules 2025, 30(17), 3655; https://doi.org/10.3390/molecules30173655 - 8 Sep 2025

Viewed by 445

Abstract

One of the most interesting applications of crude glycerol (CG) is its use for biogas production via the anaerobic co-digestion (AcoD) process. The main aim of the current study was to provide a comprehensive review on the performance of the AcoD of CG [...] Read more.

One of the most interesting applications of crude glycerol (CG) is its use for biogas production via the anaerobic co-digestion (AcoD) process. The main aim of the current study was to provide a comprehensive review on the performance of the AcoD of CG mixed with various substrates. For this purpose, analyses were performed for studies available in the literature wherein one-stage experiments were conducted. To the best of the authors’ knowledge, the present study is the first one which demonstrates an analysis of the main parameters of CG and substrates (e.g., animal manure, sewage sludge, cattle manure and food waste) used for AcoD. Moreover, a detailed analysis of the impact of selected parameters on AcoD performance was carried out. It is demonstrated that the values of key parameters characterizing the CG used for AcoD were within wide ranges. This can be explained by the fact that the composition of CG depends on many factors; for instance, these include the source of oil used for biodiesel production, processing technology, the ratio of reactants, the type of catalyst and the procedure applied. Moreover, performing a literature review allowed us to demonstrate that adding CG to feedstock caused the enhancement of process performance compared to results obtained for mono-digestion. Additionally, it was shown that, in general, increasing the concentration of CG in feedstock led to improvement of the biogas yield; however, a potential inhibitory effect should be considered. Analysis of data available in the literature allowed us to indicate that for most of the experiments performed, a methane (CH₄) content in biogas higher than 60% was obtained for CG content in feedstock up to 8% v/v. In addition, it is demonstrated that in order to evaluate the performance of AcoD performed under thermophilic conditions, more studies are required. Finally, it should be pointed out that the present study provides considerable insight into the management of CG. Full article

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78 pages, 8469 KB

Open AccessReview

Chiral Copper Catalysis in Enantioselective Domino Reactions

by Hélène Pellissier

Molecules 2025, 30(17), 3654; https://doi.org/10.3390/molecules30173654 - 8 Sep 2025

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Abstract

This review updates the field of enantioselective copper-catalysed domino reactions promoted by chiral green copper catalysts, covering the literature since 2017. These complexes are derived from a diversity of chiral ligands, including mostly bisoxazolines and biphosphines along with monophosphines, N-heterocyclic carbenes, proline [...] Read more.

This review updates the field of enantioselective copper-catalysed domino reactions promoted by chiral green copper catalysts, covering the literature since 2017. These complexes are derived from a diversity of chiral ligands, including mostly bisoxazolines and biphosphines along with monophosphines, N-heterocyclic carbenes, proline derivatives, phosphoric acids, phosphoramidates, and different types of N,N-ligands. The review shows that asymmetric copper catalysis, that suits the growing demand for greener processes, offers a real opportunity to replace toxic and expensive metals in the near future. Full article

(This article belongs to the Special Issue Applied Innovative Insights in Selective Organic Hetero-Synthesis)

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24 pages, 477 KB

Open AccessArticle

Chemical Composition and Nutritional Profile of Quinoa Sourdough Enriched with Quinoa Malts

by Agata Wojciechowicz-Budzisz, Alan Gasiński, Witold Pietrzak, Ewa Pejcz, Marzena Styczyńska and Joanna Harasym

Molecules 2025, 30(17), 3653; https://doi.org/10.3390/molecules30173653 - 8 Sep 2025

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Abstract

This study investigated the combined effects of quinoa malt addition (0%, 5%, 10%) and grain variety (white, red, black) on the nutritional and sensory properties of quinoa sourdoughs. Quinoa malt supplementation significantly (p < 0.05) enhanced fermentation characteristics, increasing titratable acidity from [...] Read more.

This study investigated the combined effects of quinoa malt addition (0%, 5%, 10%) and grain variety (white, red, black) on the nutritional and sensory properties of quinoa sourdoughs. Quinoa malt supplementation significantly (p < 0.05) enhanced fermentation characteristics, increasing titratable acidity from 20.0–20.4 to 21.2–23.8 mL NaOH/10 g and dynamic viscosity up to 733 ± 5.59 mPa·s compared to 474–611 mPa·s in controls. Malt enrichment expanded the volatile profile from predominantly alcohols and acids to include 25 distinct compounds spanning esters, terpenes, aldehydes, phenols, and furans, creating more complex aromatic profiles. Lactic acid production increased significantly in all malted samples, reaching 12.92 ± 0.00 g/kg in black quinoa with 10% malt. Black quinoa sourdoughs exhibited superior nutritional density with the highest protein (17.3 ± 0.1%), total dietary fiber (17.94 ± 0.14%), potassium (7896 ± 176 mg/kg), and manganese (55.65 ± 0.47 mg/kg) contents (p < 0.05). White quinoa variants demonstrated the highest acidity (pH 4.28 ± 0.01) and mineral bioavailability (magnesium: 5371 ± 70 mg/kg), while red quinoa achieved maximum viscosity (733 ± 5.59 mPa·s) and zinc content (38.08 ± 0.26 mg/kg). Volatile compound distribution varied significantly by variety, with white quinoa favoring ester and terpene formation, red quinoa promoting aldehydes and terpenes, and black quinoa accumulating phenols and furans. These findings demonstrate that strategic combination of quinoa variety selection and malt optimization can produce functionally enhanced, gluten-free sourdoughs with targeted nutritional and sensory characteristics for specialty bakery applications. Full article

(This article belongs to the Special Issue Advances in Physicochemical Properties of Innovative Food Products During Processing)

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19 pages, 3146 KB

Open AccessArticle

Polymorph Selection and Derivatization in Enantiomerically Pure Medicarpin: Crystallographic and Computational Insights

by Santiago José Guevara-Martínez, Rafael Herrera-Bucio, Marco Antonio Pérez-Cisneros, Gilberto Velázquez-Juárez, Fredy Geovannini Morales-Palacios and Stephanie García-Zavala

Molecules 2025, 30(17), 3652; https://doi.org/10.3390/molecules30173652 - 8 Sep 2025

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Abstract

Polymorphism critically influences the solid-state properties of organic molecules, affecting stability, solubility, and functionality. We investigated the polymorphic behavior of enantiomerically pure (+)-(6aS,11aS)-medicarpin through combined experimental and computational analyses. Single-crystal X-ray diffraction revealed two distinct chiral polymorphs: the previously reported monoclinic P2₁ [...] Read more.

Polymorphism critically influences the solid-state properties of organic molecules, affecting stability, solubility, and functionality. We investigated the polymorphic behavior of enantiomerically pure (+)-(6aS,11aS)-medicarpin through combined experimental and computational analyses. Single-crystal X-ray diffraction revealed two distinct chiral polymorphs: the previously reported monoclinic P2₁ form and a newly identified orthorhombic P2₁2₁2₁ form with a fully chiral packing arrangement. The discovery of this previously unreported polymorph underscores the subtle yet decisive effects of solvent and conformational flexibility in directing crystallization. Detailed structural analysis reveals that, whereas the P2₁ form is only stabilized by a single dominant electrostatic interaction, the P2₁2₁2₁ form features a more complex network comprising C-H···π contacts, bifurcated C-H···O hydrogen bonds, and aromatic edge-to-face interactions. Further investigation of a functionalized p-nitrobenzoate derivative corroborates the critical influence of molecular substituents and crystallization conditions on packing motifs. Lattice energy DFT calculations confirm that each polymorph is stabilized by distinct electrostatic and dispersive interaction patterns, illustrating the complex energetic landscape of polymorph selection. Altogether, this work provides a framework for understanding and anticipating which polymorph is likely to form under specific solvent and crystallization conditions, offering insights for future strategies in materials design and guiding the pursuit of patentable crystalline forms in pharmaceutical applications. Full article

(This article belongs to the Special Issue Crystal Structures of Tricky, Unexpected, Labile or Difficult Molecular Structures by Diffraction Methods)

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19 pages, 1423 KB

Open AccessArticle

Design and Evaluation of Indole-Based Schiff Bases as α-Glucosidase Inhibitors: CNN-Enhanced Docking, MD Simulations, ADMET Profiling, and SAR Analysis

by Seema K. Bhagwat, Sachin V. Patil, Abraham Vidal-Limon, J. Oscar C. Jimenez-Halla, Balasaheb K. Ghotekar, Vivek D. Bobade, Irving David Pérez-Landa, Enrique Delgado-Alvarado, Fabiola Hernández-Rosas and Tushar Janardan Pawar

Molecules 2025, 30(17), 3651; https://doi.org/10.3390/molecules30173651 - 8 Sep 2025

Viewed by 450

Abstract

Type 2 diabetes mellitus (T2DM) remains a global health challenge, prompting the development of novel α-glucosidase inhibitors (AGIs) to regulate postprandial hyperglycemia. This study reports the design, synthesis, and evaluation of indole-based Schiff base derivatives (4a–j) bearing a fixed [...] Read more.

Type 2 diabetes mellitus (T2DM) remains a global health challenge, prompting the development of novel α-glucosidase inhibitors (AGIs) to regulate postprandial hyperglycemia. This study reports the design, synthesis, and evaluation of indole-based Schiff base derivatives (4a–j) bearing a fixed methoxy group at the C₅ position. This substitution was strategically introduced to enhance lipophilicity, electronic delocalization, and π-stacking within the enzyme active site. Among the series, compound 4g (3-bromophenyl) exhibited the highest inhibitory activity (IC₅₀ = 10.89 µM), outperforming the clinical reference acarbose (IC₅₀ = 48.95 µM). The mechanism was supported by in silico analyses, such as the Density Functional Theory (DFT), molecular electrostatic potential (MEP) mapping, and molecular dynamics simulations, and CNN-based docking revealed that 4g engages in stable hydrogen bonding and π–π interactions with key residues (Asp327, Asp542, and Phe649), suggesting a potent and selective mode of inhibition. In silico ADMET predictions indicated favorable pharmacokinetic properties. Together, these results establish C₅–methoxy substitution as a viable strategy to enhance α-glucosidase inhibition in indole-based scaffolds. Full article

(This article belongs to the Special Issue 10th Anniversary of the Bioorganic Chemistry Section of Molecules)

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17 pages, 2858 KB

Open AccessArticle

From Mushrooms to Molecules: Exploring Depsidones in Ganoderma lucidum for Antioxidant and Anticancer Applications

by Sayed H. A. Mohamed, Yehia A.-G. Mahmoud, Mohamed Y. Bediway, Sobhy E. Elsilk, Mohammed Yosri, Kamel Metwally, Nader E. Abo-Dya, Galal Yahya, Mervt Almostafa and Atef A. El-Hela

Molecules 2025, 30(17), 3650; https://doi.org/10.3390/molecules30173650 - 8 Sep 2025

Viewed by 348

Abstract

Fungi are a prolific source of diverse bioactive metabolites, yet many remain unexplored. Among these, depsidones are a rare class of compounds with significant biological potential, but they are seldom reported in mushrooms. This study investigated the medicinal fungus Ganoderma lucidum, known [...] Read more.

Fungi are a prolific source of diverse bioactive metabolites, yet many remain unexplored. Among these, depsidones are a rare class of compounds with significant biological potential, but they are seldom reported in mushrooms. This study investigated the medicinal fungus Ganoderma lucidum, known for its extensive therapeutic use in traditional medicine. Fruiting bodies were extracted using petroleum ether, ethyl acetate, n-butanol, and methanol. Extracts were screened phytochemically and assessed for total phenolic content and antioxidant activity using the DPPH assay. Ethyl acetate extract exhibited the highest phenolic yield and antioxidant potential and was subsequently evaluated for cytotoxicity against HepG2, HCT116, MCF7, and A549 cancer cell lines. It showed notable anticancer activity with minimal toxicity to normal Vero cells. UHPLC/Q-TOF-MS/MS analysis of G. lucidum ethyl acetate extract tentatively identified nine minor depsidones including mollicellin G, simplicildone I, mollicellin B, talaromyone B, simplicildone A, purpactin C, emeguisin B, mollicellin E, and simplicildone D on the basis of high-resolution negative-mode detection and characteristic MS/MS fragmentation patterns. Molecular docking revealed strong binding affinities between these compounds and cancer-related targets (AKT1, CDK2, ERK1, TNFα), with simplicildone D and mollicellin G demonstrating particularly high interactions. These findings provide mechanistic insights into the observed bioactivity and highlight G. lucidum as a promising source of therapeutic depsidones for future anticancer drug development. Full article

(This article belongs to the Special Issue Potential of Natural Products as Drug Leads Possessing Antioxidant, Antiaging and Anticancer Properties)

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24 pages, 2898 KB

Open AccessArticle

Evaluating UV Stability of Miscanthus × giganteus Particles via Radiografting of UV Absorbers

by Roland El Hage, Dominique Lafon-Pham and Rodolphe Sonnier

Molecules 2025, 30(17), 3649; https://doi.org/10.3390/molecules30173649 - 8 Sep 2025

Viewed by 407

Abstract

Miscanthus × giganteus particles possess excellent advantages in biodegradability and sustainability. However, their susceptibility to ultraviolet (UV) degradation limits wider outdoor applications. In the present work, electron beam (e-beam) radiation-induced grafting was used for the first time to attempt covalent grafting [...] Read more.

Miscanthus × giganteus particles possess excellent advantages in biodegradability and sustainability. However, their susceptibility to ultraviolet (UV) degradation limits wider outdoor applications. In the present work, electron beam (e-beam) radiation-induced grafting was used for the first time to attempt covalent grafting of UV absorbers onto miscanthus particles to address a major challenge in natural fiber stabilization. Two UV absorbers, 2-hydroxy-4-(methacryloyloxy) benzophenone (HMB) and 2-(4-benzoyl-3-hydroxyphenoxy) ethyl acrylate (BHEA), were explored using both pre-irradiation and simultaneous approaches. Pre-irradiation grafting did not achieve useful covalent fixation of HMB or BHEA, due in part to the premature decay of radicals at elevated temperatures and with solvent use, and the lignin-based quenching of radicals. Solvent-free mutual irradiation grafting failed due to immobility of the UV absorbers, while grafting of HMB in solvent failed due to radical-scavenging behavior. Grafting of BHEA was successfully achieved under solvent-based simultaneous irradiation, reaching up to 38 wt % DG in a butanone/2.5% H₂SO₄ system. This condition led to the improved UV stability of miscanthus particles, in which color change was reduced significantly after 1000 h of accelerated weathering; this was mainly linked to a beneficial pre-darkening effect which was induced by the presence of the acid. This work proposes a route of grafting strategy that aims to improve the photostability of miscanthus particles, paving the way for durable bio-based materials in outdoor composite applications. Full article

(This article belongs to the Special Issue Advances in Polymer Materials Based on Lignocellulosic Biomass)

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23 pages, 2763 KB

Open AccessArticle

The Effect of Caffeic Acid on Zn Corrosion in NaCl: Electrochemical Studies

by Aleksander Kucharek, Elżbieta Kuśmierek, Ewa Chrześcijańska, Waldemar Maniukiewicz, Jacek Rogowski, Aleksandra Bednarek and Andrzej Żarczyński

Molecules 2025, 30(17), 3648; https://doi.org/10.3390/molecules30173648 - 8 Sep 2025

Viewed by 508

Abstract

Caffeic acid (CA) can be applied as a green corrosion inhibitor for metals and alloys. The inhibition properties of caffeic acid for Zn in 0.1 M NaCl were investigated using electrochemical methods. The changes in Zn morphology were studied via scanning electron microscopy [...] Read more.

Caffeic acid (CA) can be applied as a green corrosion inhibitor for metals and alloys. The inhibition properties of caffeic acid for Zn in 0.1 M NaCl were investigated using electrochemical methods. The changes in Zn morphology were studied via scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) techniques. Potentiodynamic polarisation (PDP) and electrochemical impedance spectroscopy (EIS) measurements proved that caffeic acid applied in the form of coatings on Zn surface was more effective than the addition of CA to NaCl. Furthermore, CA coatings revealed better corrosion protection with increasing duration of immersion. The highest inhibition efficiency was achieved for CA coating obtained from ethanol solution of CA (10 mM), and its value was almost 95%. The positive impact of CA coatings on the corrosion of Zn surface was confirmed with SEM-EDS, XRD and TOF-SIMS measurements. They proved not only the presence of CA on the Zn surface but also noticeably a lower amount of Zn corrosion products. Full article

(This article belongs to the Special Issue Corrosion Electrochemistry: A Themed Issue in Honor of the Many Contributions of Prof. Dr. Changjian Lin)

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1 pages, 138 KB

Open AccessCorrection

Correction: Şeker et al. Comparative Analysis of Phenolic, Carotenoid, and Elemental Profiles in Three Crataegus Species from Şebinkarahisar, Türkiye: Implications for Nutritional Value and Safety. Molecules 2025, 30, 2934

by Mehmet Emin Şeker, Ayşegül Erdoğan and Emriye Ay

Molecules 2025, 30(17), 3647; https://doi.org/10.3390/molecules30173647 - 8 Sep 2025

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Abstract

In the original publication [...] Full article

23 pages, 7687 KB

Open AccessReview

Recent Advances in the Synthesis and Applications of Nitrogen-Containing Macrocyclic Arenes

by Jianhang Hu, Wanhua Wu and Cheng Yang

Molecules 2025, 30(17), 3646; https://doi.org/10.3390/molecules30173646 - 7 Sep 2025

Viewed by 1197

Abstract

Macrocyclic arenes are rich-electron macrocycles bridged by methylene or methyl groups from aromatic rings substituted by hydroxyl or alkoxy groups. It has attracted great interest in host–guest chemistry and supramolecular self-assembly due to its clear cavity, adjustable structure and multifunctional binding ability. In [...] Read more.

Macrocyclic arenes are rich-electron macrocycles bridged by methylene or methyl groups from aromatic rings substituted by hydroxyl or alkoxy groups. It has attracted great interest in host–guest chemistry and supramolecular self-assembly due to its clear cavity, adjustable structure and multifunctional binding ability. In particular, nitrogen-containing macrocyclic arenes including (hetero) aromatic moieties—constructed from building blocks such as pyrrole, carbazole, phenothiazine, and imidazole—have undergone rapid development, yielding a new generation of functional macrocycles, including calix[4]carbazoles, Tröger’s base-derived macrocycles, and phenothiazine-based architectures. These nitrogen-functionalized macrocycles feature rich chemical derivatization potential, unique structural and host–guest characteristics, and exceptional photophysical properties. They show great promise in molecular recognition, selective adsorption and separation, and the development of advanced functional materials. This review summarizes recent advances in the design, synthesis, and application of nitrogen-containing macrocyclic arenes, with a particular focus on structure–property relationships and emerging functions. Full article

(This article belongs to the Section Organic Chemistry)

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22 pages, 7241 KB

Open AccessArticle

Osteogenic Differentiation in Chitosan-Based Scaffolds via P28 and VEGF Delivery

by Keran Zhou, Bianca Simonassi-Paiva, Robert Pogue, Emma Murphy, Zhi Cao, Margaret Brennan Fournet and Declan M. Devine

Molecules 2025, 30(17), 3645; https://doi.org/10.3390/molecules30173645 - 7 Sep 2025

Viewed by 1373

Abstract

Repairing large bone defects remains a significant clinical challenge due to the limitations of current treatments, including infection risk, donor site morbidity, and insufficient vascularization. The autograft is still the gold standard for large bone defects. In this study, we developed chitosan-based (CS-based) [...] Read more.

Repairing large bone defects remains a significant clinical challenge due to the limitations of current treatments, including infection risk, donor site morbidity, and insufficient vascularization. The autograft is still the gold standard for large bone defects. In this study, we developed chitosan-based (CS-based) scaffolds, incorporating with hydroxyapatite (HAp) and fluorapatite (FAp) ceramics, fabricated by UV crosslinking and freeze-drying, and loaded with P28 peptide, alone or in combination with vascular endothelial growth factor (VEGF), to evaluate the effect of dual bioactive factor delivery. We hypothesized that CS-based scaffolds would optimize ceramic composition and co-delivery of P28 and VEGF, and can enhance early-stage osteogenic differentiation and support bone regeneration. The CS-based scaffolds were characterized by their physicochemical properties, including swelling behavior, mechanical strength, porosity, and in vitro degradation. Biological evaluations were performed including cell proliferation assays, ALP activity, ARS staining, and RT-qPCR, to assess osteogenic differentiation. The results showed that the scaffolds had high porosity, excellent swelling behavior, and degraded within 8 weeks. Dual delivery of P28 and VEGF significantly enhanced early osteogenic markers, indicating a complementary effect. These findings demonstrated that CS-based scaffolds with an optimized ceramic ratio and bioactive factor incorporation have the potential to facilitate bone regeneration. Full article

(This article belongs to the Special Issue Synthesis of Nanomaterials and Their Applications in Biomedicine—2nd Edition)

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15 pages, 5228 KB

Open AccessArticle

Construction of Hollow TiO₂/ZnS Heterojunction Photocatalysts for Highly Enhanced Photodegradation of Tetracycline Hydrochloride

by Ying Zhang, Anhui Su, Yuqin Ding, Yuhan Wu, Yapeng Tan and Jianguo Chang

Molecules 2025, 30(17), 3644; https://doi.org/10.3390/molecules30173644 - 7 Sep 2025

Viewed by 1253

Abstract

TiO₂ photocatalysts exhibit great potential in solar fuel production and environmental remediation, yet their practical applications are often hindered by high electron-hole recombination rates. This study presents a novel strategy for fabricating hollow anatase TiO₂-modified ZnS heterostructures (TiO₂/ZnS) [...] Read more.

TiO₂ photocatalysts exhibit great potential in solar fuel production and environmental remediation, yet their practical applications are often hindered by high electron-hole recombination rates. This study presents a novel strategy for fabricating hollow anatase TiO₂-modified ZnS heterostructures (TiO₂/ZnS) via a simple hydrothermal method. The heterostructure effectively combines the high electron mobility of ZnS, which facilitates rapid photogenerated electron transfer, with the high specific surface area of hollow TiO_2, which enhances pollutant adsorption. As a result, TiO₂/ZnS demonstrates superior tetracycline degradation efficiency due to optimized charge separation and improved accessibility to reactive sites, compared to pristine TiO₂ and ZnS. Furthermore, the enhanced photocatalytic activity is attributed to efficient charge separation facilitated by Type-II heterojunctions between ZnS and anatase TiO₂. Cycling tests reveal that TiO₂/ZnS retains over 94% of its activity after 5 cycles. This work offers a versatile approach for stabilizing metal oxides through heterostructure engineering, with significant implications for scalable environmental catalysis. Full article

(This article belongs to the Special Issue Advanced Materials for Photocatalytic and Photoelectrocatalytic Water-Splitting)

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18 pages, 1005 KB

Open AccessPerspective

The Next Frontier in the Study of Noncovalent Bonding: Transition Metals

by Steve Scheiner

Molecules 2025, 30(17), 3643; https://doi.org/10.3390/molecules30173643 - 7 Sep 2025

Viewed by 666

Abstract

As work continues unabated in the study of noncovalent bonding, particularly σ-hole bonds, new challenges have emerged as the participation of transition metals in interactions of this sort is fast becoming appreciated. While there are certain similarities with the halogen, chalcogen, etc, bonds, [...] Read more.

As work continues unabated in the study of noncovalent bonding, particularly σ-hole bonds, new challenges have emerged as the participation of transition metals in interactions of this sort is fast becoming appreciated. While there are certain similarities with the halogen, chalcogen, etc, bonds, in which the main group elements participate, there are certain unique properties of these metal atoms that must be analyzed before a complete understanding can be attained. As one example, these atoms tend to act simultaneously as both electron donors and acceptors, a synergistic action that amplifies the overall bond strength. Ideas are expressed in this paper to hopefully guide future work in this exciting new arena. Full article

(This article belongs to the Section Physical Chemistry)

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19 pages, 1904 KB

Open AccessArticle

The Composition of Volatile Organic Compounds Correlates with the Genetic Variability Within the Calypogeia sphagnicola Species Complex (Marchantiophyta, Calypogeiaceae)

by Rafał Wawrzyniak, Małgorzata Guzowska, Katarzyna Buczkowska and Alina Bączkiewicz

Molecules 2025, 30(17), 3642; https://doi.org/10.3390/molecules30173642 - 7 Sep 2025

Viewed by 561

Abstract

This paper presents the first comprehensive analysis of the composition of volatile organic compounds (VOCs) present in the liverwort Calypogeia sphagnicola belonging to the Calypogeiaceae family. Based on DNA markers, three genetically distinct groups were examined: C. sphagnicola f. sphagnicola; C. sphagnicola [...] Read more.

This paper presents the first comprehensive analysis of the composition of volatile organic compounds (VOCs) present in the liverwort Calypogeia sphagnicola belonging to the Calypogeiaceae family. Based on DNA markers, three genetically distinct groups were examined: C. sphagnicola f. sphagnicola; C. sphagnicola f. paludosa; and C. sphagnicola LC. The volatile organic compounds were determined using headspace solid-phase microextraction (HS-SPME) and analyzed by gas chromatography combined with mass spectrometry (GC-MS). A total of 65 organic compounds were detected from the tested plant material and 42 compounds were identified. The chemical analysis revealed distinct VOC profiles corresponding to three genetically defined groups. Sesquiterpenes (49.91–64.21%) and sesquiterpenoids (4.99–11.56%) dominated the VOC profiles, followed by monoterpenes (0.95–4.73%), aromatic compounds (2.43–5.12%), and aliphatic compounds (0.74–1.55%). It is noteworthy that aliphatic compounds were absent in C. sphagnicola f. paludosa, whereas the most abundant compounds were bicyclogermacrenes (20.92–33.60%) and anastreptenes (6.75–14.95%). Marker compounds were selected to allow for the rapid identification of individual genetic groups. Full article

(This article belongs to the Special Issue Plant Metabolites: Isolation, Phytochemistry, and Biological Activities)

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28 pages, 2130 KB

Open AccessReview

Bacteriophage Power: Next-Gen Biocontrol Strategies for Safer Meat

by Magdalena Efenberger-Szmechtyk and Agnieszka Nowak

Molecules 2025, 30(17), 3641; https://doi.org/10.3390/molecules30173641 - 6 Sep 2025

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Abstract

Lytic bacteriophages, viruses that attack and kill bacteria cells, can be used in food as biocontrol agents to prevent the growth of pathogenic bacteria. Meat is highly susceptible to bacterial growth, including pathogenic species, the control of which is crucial. Antibiotic use by [...] Read more.

Lytic bacteriophages, viruses that attack and kill bacteria cells, can be used in food as biocontrol agents to prevent the growth of pathogenic bacteria. Meat is highly susceptible to bacterial growth, including pathogenic species, the control of which is crucial. Antibiotic use by breeders has resulted in bacterial resistance, which remains a huge problem; bacteriophages have emerged as an interesting alternative. In the literature, the influence of bacteriophages on common foodborne pathogens, such as Salmonella sp., Listeria monocytogenes, Campylobacter jejuni, Yersinia enterocolitica, Escherichia coli, and Shigella sp., has been described. Some phage preparations can show synergistic effects when used with other antimicrobial agents. However, data on the use of bacteriophages to inhibit the growth of meat spoilage bacteria are limited. Bacteriophages can also synthesize endolysins, which possess antimicrobial properties. Contrary to bacteriophages, which are active against only a narrow range of microorganisms (usually one bacterial species), endolysins show a broad spectrum of activity. Full article

(This article belongs to the Special Issue Antimicrobial Compounds and Biocontrol Strategies in Food Microbiology and Safety)

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17 pages, 1248 KB

Open AccessArticle

Lipids from Oilcakes—High Quality Ingredients for Functional Food Products

by Ancuța Petraru, Sonia Amariei and Lacrimioara Senila

Molecules 2025, 30(17), 3640; https://doi.org/10.3390/molecules30173640 - 6 Sep 2025

Viewed by 721

Abstract

Fatty acids (FAs) are vital for human nutrition and are classified into three categories (saturated, unsaturated, and trans). FAs have different physiological effects and can contribute to health problems in different ways. By-products from the oil industry are rich in bioactive compounds. These [...] Read more.

Fatty acids (FAs) are vital for human nutrition and are classified into three categories (saturated, unsaturated, and trans). FAs have different physiological effects and can contribute to health problems in different ways. By-products from the oil industry are rich in bioactive compounds. These make them useful for further utilization in food formulation. There is a quantity of residual oil in the oilcake. Analysis of the fatty acid composition shows that unsaturated fatty acids are predominant. The predominant fatty acids in oilcakes are arachidic (sunflower), oleic, elaidic (flax), linoleic (LA), and linolelaidic (hemp, rape, and sesame) acids. The favorable and ideal (within the regulatory recommendations) results for the n-6/n-3 ratios of 3:1 indicate the high nutritional profile with beneficial effects for the human body of the oilcakes. The hypocholesterolemic/hypercholesterolemic for all samples ranged from 4.52 to 116.06, while atherogenicity and thrombogenicity indexes ranged from 0.01 to 0.3. This is in line with the favorable values found in the literature benchmarks. Full article

(This article belongs to the Special Issue Research Progress on Functional Lipids and Their Applications in Health Food Systems)

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31 pages, 5362 KB

Open AccessArticle

Sustainable Valorization of Posidonia Waste Ash for Phosphate Removal: A Surface Complexation Approach Under Variable Water Chemistry

by Jesús Mengual and Juan A. González

Molecules 2025, 30(17), 3639; https://doi.org/10.3390/molecules30173639 - 6 Sep 2025

Viewed by 682

Abstract

Phosphorus pollution represents a persistent and significant threat to aquatic ecosystems, particularly within the Mediterranean region, where ongoing eutrophication continues to compromise both water quality and biodiversity. Concurrently, the accumulation of Posidonia oceanica residues along coastal areas presents a biomass management challenge. This [...] Read more.

Phosphorus pollution represents a persistent and significant threat to aquatic ecosystems, particularly within the Mediterranean region, where ongoing eutrophication continues to compromise both water quality and biodiversity. Concurrently, the accumulation of Posidonia oceanica residues along coastal areas presents a biomass management challenge. This study explores the sustainable use of thermally treated Posidonia ash as a low-cost, bio-based adsorbent for phosphate removal from water. Batch experiments under varying phosphate concentrations, pH, hardness, and alkalinity revealed high removal capacities (33.5–58.7 mg/g). A novel surface complexation model (SCM) was developed and validated using spectroscopic techniques to elucidate the mechanisms of phosphate retention. The SCM outperformed conventional isotherm models by providing mechanistic insights into adsorption behavior. Phosphate adsorption was found to be pH-dependent, occurring via surface complexation to neutral and basic surface sites. The release of Ca²⁺ and Mg²⁺ ions facilitated ternary complex formation and precipitation. Under alkaline conditions, competitive adsorption between phosphate and carbonate ions was observed. This study demonstrates the dual benefit of Posidonia oceanica ash: efficient phosphate removal and its reuse as a phosphorus reservoir, offering a circular strategy for tackling nutrient pollution and promoting coastal biomass valorization. Full article

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

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29 pages, 8735 KB

Open AccessArticle

Fluorescence of 4-Cyanophenylhydrazones: From Molecular Design to Electrospun Polymer Fibers

by Paulina Sobczak-Tyluś, Tomasz Sierański, Marcin Świątkowski, Agata Trzęsowska-Kruszyńska and Oskar Bogucki

Molecules 2025, 30(17), 3638; https://doi.org/10.3390/molecules30173638 - 6 Sep 2025

Viewed by 651

Abstract

The rational design of advanced functional materials with tailored fluorescence hinges on a profound understanding of the complex interplay between a molecule’s intrinsic structure and its local solid-state environment. This work systematically investigates these factors by employing a dual approach that combines targeted [...] Read more.

The rational design of advanced functional materials with tailored fluorescence hinges on a profound understanding of the complex interplay between a molecule’s intrinsic structure and its local solid-state environment. This work systematically investigates these factors by employing a dual approach that combines targeted molecular synthesis with the subsequent modulation of the fluorophore’s properties within polymer matrices. First, a series of phenylhydrazone derivatives was synthesized, providing compounds with intense, solid-state fluorescence in the blue spectrum (421–494 nm). It was demonstrated that their photophysical properties were intricately linked to the substituent’s nature, which simultaneously modulated their intramolecular electron density and conformational rigidity while also governing their specific intermolecular packing in the solid state. Subsequently, we investigated the role of the supramolecular environment by embedding two fluorophores with distinct electronic profiles into electrospun poly (N-vinylpyrrolidone) (PVP) and polystyrene (PS) matrices. Our results reveal that the polymer matrix is not a passive host but an active component; it governs dye aggregation, induces significant blue shifts, and most critically, can impart exceptional thermal stability. Specifically, the PVP matrix shielded the embedded dyes from thermal quenching, maintaining robust fluorescence up to 100 °C. By combining molecular-level synthesis with matrix-level engineering, this work demonstrates a powerful strategy for the rational design of emissive materials, where properties like color and operational stability can be deliberately tuned for demanding applications in optoelectronics and sensing. Full article

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13 pages, 2275 KB

Open AccessArticle

Investigating the Mars–van Krevelen Mechanism for CO Capture on the Surface of Carbides

by Naveed Ashraf and Younes Abghoui

Molecules 2025, 30(17), 3637; https://doi.org/10.3390/molecules30173637 - 6 Sep 2025

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Abstract

Electrochemical reduction processes enable the CO to be converted into a useful chemical fuel. Our study employs density functional theory calculations to analyze the (110) facets of the transition metal carbide surfaces for CO capture, incorporating the Mars–van Krevelen (MvK) mechanism. All the [...] Read more.

Electrochemical reduction processes enable the CO to be converted into a useful chemical fuel. Our study employs density functional theory calculations to analyze the (110) facets of the transition metal carbide surfaces for CO capture, incorporating the Mars–van Krevelen (MvK) mechanism. All the possible adsorption sites on the surface, including carbon, metal, and bridge sites, were fully investigated. The findings indicate that the carbon site is more active relative to the other adsorption sites examined. The CO hydrogenation paths have been comprehensively investigated on all the surfaces, and the free energy diagrams have been constructed towards the product. The results conclude that the TiC is the most promising candidate for the formation of methane, exhibiting an onset potential of −0.44 V. The predicted onset potential for CrC, MoC, NbC, VC, WC, ZrC, and HfC are −0.86, −0.61, −0.61, −0.93, −0.87, −0.61, and −0.81 V, respectively. Our calculated results demonstrate that MvK is selectively relevant to methane synthesis. Additionally, we investigated the stability of these surfaces against decomposition and conversion to pure metals concerning thermodynamics and kinetics. It was found that these carbides could remain stable under ambient conditions. The exergonic adsorption of hydrogen on carbon sites, requiring smaller potential values for product formation, and stability against decomposition indicate that these surfaces are highly suitable for CO reduction reactions using the MvK mechanism. Full article

(This article belongs to the Special Issue Carbon-Based Electrochemical Materials for Energy Storage)

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21 pages, 9210 KB

Open AccessArticle

The Influence of NaClO on the Biocorrosion of Carbon Steel Induced by Chlorella vulgaris in Artificial Seawater

by Junnan Zhang, Qi Fu and Guang-Ling Song

Molecules 2025, 30(17), 3636; https://doi.org/10.3390/molecules30173636 - 5 Sep 2025

Viewed by 737

Abstract

Microbiologically influenced corrosion (MIC) poses a significant threat to carbon steel facilities in marine environments. Due to its environmental friendliness and excellent bactericidal effect, NaClO has been widely applied in the marine industry to inhibit MIC. In fact, algae can also cause severe [...] Read more.

Microbiologically influenced corrosion (MIC) poses a significant threat to carbon steel facilities in marine environments. Due to its environmental friendliness and excellent bactericidal effect, NaClO has been widely applied in the marine industry to inhibit MIC. In fact, algae can also cause severe biocorrosion to carbon steels. However, there are very few studies on the biocorrosion induced by algae, and thus the algicidal effect of bactericide NaClO is still unclear. In this study, the biocorrosion of 45# mild steel induced by Chlorella vulgaris (C. vulgaris) and the effect of NaClO on the biocorrosion were systematically investigated. The results showed that the corrosion rate of the steel in C. vulgaris-containing biotic artificial seawater was significantly higher than that in the abiotic solution. An increase in NaClO concentration resulted in a higher corrosion rate of the steel in general but relatively mild local corrosion penetration. The overall corrosion damage of the steel in the biofilm-covered areas was alleviated, while the corrosion penetration in the biofilm-discontinuous area became deeper after NaClO addition. The addition of 1 ppm NaClO into the biotic artificial seawater could not significantly inhibit the growth of C. vulgaris. When NaClO concentration increased to 10 ppm, the growth of C. vulgaris was markedly suppressed, resulting in a lower corrosion rate than that at 0 ppm and 1 ppm NaClO. At 100 ppm of NaClO, C. vulgaris cells were completely killed, and the overall corrosion rate in the biotic solution was close to that in the abiotic solution. Based on the experimental observations, algae-induced corrosion and its inhibition by NaClO were finally analyzed. Full article

(This article belongs to the Special Issue Corrosion Electrochemistry: A Themed Issue in Honor of the Many Contributions of Prof. Dr. Changjian Lin)

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15 pages, 1752 KB

Open AccessArticle

A Simple and Reliable Method for the Determination of Isorhapontigenin in Murine Biological Matrices: Application in a Tissue Distribution Study

by Yuhui Yang, Hongrui Jin, Boyu Liao, Feifei Gao, Yihan Yang, Xinyi Wang, Zhang Liu, Jingsi Liang, Jingbo Wang, Paul Chi-Lui Ho, Hui Liu and Hai-Shu Lin

Molecules 2025, 30(17), 3635; https://doi.org/10.3390/molecules30173635 - 5 Sep 2025

Viewed by 769

Abstract

Isorhapontigenin (trans-3,5,4′-trihydroxy-3′-methoxystilbene; ISO), a dietary derivative of resveratrol (trans-3,5,4′-trihydroxystilbene; RES), exhibits diverse health-promoting properties. To facilitate its potential development as a nutraceutical, a simple and reliable high-performance liquid chromatography (HPLC) method was developed and validated for the quantification of [...] Read more.

Isorhapontigenin (trans-3,5,4′-trihydroxy-3′-methoxystilbene; ISO), a dietary derivative of resveratrol (trans-3,5,4′-trihydroxystilbene; RES), exhibits diverse health-promoting properties. To facilitate its potential development as a nutraceutical, a simple and reliable high-performance liquid chromatography (HPLC) method was developed and validated for the quantification of ISO in various murine biological matrices. Chromatographic separation was achieved with a reversed-phase HPLC column through a 17 min gradient delivery of a mixture of acetonitrile and formic acid (0.1% v/v) at a flow rate of 1.5 mL/min at 50 °C. Quantification was performed using ultraviolet (UV) detection at 325 nm, with a lower limit of quantification (LLOQ) of 15 ng/mL in both plasma and tissue homogenate samples. The method demonstrated excellent selectivity, accuracy, and precision, and ISO remained stable under the tested conditions. This method was subsequently employed to investigate the tissue distribution of ISO in mice following oral administration at a dose of 200 µmol/kg (equivalent to 51.7 mg/kg). ISO was rapidly absorbed and extensively distributed across major pharmacologically relevant organs. Despite its limited aqueous solubility, its oral absorption was not significantly compromised. Given its oral bioavailability and broad tissue distribution, ISO represents a promising candidate for further nutraceutical development. Full article

(This article belongs to the Special Issue Chromatography and Spectrometry in Food Safety and Pharmaceutical Analysis)

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18 pages, 9548 KB

Open AccessArticle

Bufalin Suppresses Colorectal Cancer Liver Metastasis by Inhibiting De Novo Fatty Acid Synthesis via the PI3K/AKT-Mediated SREBP1/FASN Pathway

by Wenwen Pang, Xiang Li, Suying Yan, Junshi Zhang, Ping Wu, Haiyang Yu, Bowei Zhang and Chunze Zhang

Molecules 2025, 30(17), 3634; https://doi.org/10.3390/molecules30173634 - 5 Sep 2025

Viewed by 725

Abstract

Background: Colorectal cancer (CRC) is the third most common cancer worldwide, with liver metastasis being the leading cause of mortality. De novo fatty acid synthesis plays a critical role in CRC progression and metastasis. Bufalin, a cardiotonic steroid isolated from toad skin, has [...] Read more.

Background: Colorectal cancer (CRC) is the third most common cancer worldwide, with liver metastasis being the leading cause of mortality. De novo fatty acid synthesis plays a critical role in CRC progression and metastasis. Bufalin, a cardiotonic steroid isolated from toad skin, has demonstrated anticancer activity in multiple preclinical models. However, the mechanisms underlying its suppression of CRC metastasis and modulation of fatty acid synthesis remain to be elucidated. Methods: The effects of bufalin on CRC cell proliferation, migration, and apoptosis were assessed via colony formation, wound healing, and flow cytometry assays. Transcriptome analysis identified bufalin-affected pathways, with changes in gene and protein expression. FASN protein levels were quantified using ELISA. Results: Bufalin inhibited proliferation and migration of CRC cells and induced the apoptosis of LoVo and HCT8 cells. Transcriptome analysis highlighted lipid metabolism pathways as potential mediators of bufalin’s anti-metastatic activity. Notably, bufalin reduced the expression of fatty acid synthase (FASN) and suppressed CRC metastasis. In vivo experiments demonstrated that bufalin attenuated CRC progression and liver metastasis by inhibiting de novo fatty acid synthesis through the PI3K/AKT-mediated SREBP1/FASN pathway. Conclusions: Bufalin inhibits de novo fatty acid synthesis via the PI3K/AKT-mediated SREBP1/FASN pathway, suppressing CRC progression and liver metastasis. Full article

(This article belongs to the Special Issue Pharmacological Effects of Natural Products: Antioxidant, Anti-Inflammatory and Anticancer Activities)

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14 pages, 4225 KB

Open AccessArticle

Portable Bacterial Cellulose-Based Fluorescent Sensor for Rapid and Sensitive Detection of Copper in Food and Environmental Samples

by Hongyuan Zhang, Qian Zhang, Xiaona Ji, Bing Han, Jieqiong Wang and Ce Han

Molecules 2025, 30(17), 3633; https://doi.org/10.3390/molecules30173633 - 5 Sep 2025

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Abstract

Copper ions (Cu²⁺), indispensable in physiological processes yet toxic at elevated concentrations, require sensitive on-site monitoring. Here, a portable fluorescent sensing film (Y-CDs@BCM) was fabricated by anchoring yellow-emitting carbon dots (Y-CDs) into bacterial cellulose films, which enables rapid and sensitive detection [...] Read more.

Copper ions (Cu²⁺), indispensable in physiological processes yet toxic at elevated concentrations, require sensitive on-site monitoring. Here, a portable fluorescent sensing film (Y-CDs@BCM) was fabricated by anchoring yellow-emitting carbon dots (Y-CDs) into bacterial cellulose films, which enables rapid and sensitive detection of Cu²⁺ in complex real-world samples. The yellow fluorescent carbon dots (Y-CDs) were synthesized with the aid of o-phenylenediamine and 1-octyl-3-methylimidazolium tetrafluoroborate as precursors, exhibiting excellent fluorescence stability. The fluorescence of Y-CDs was selectively quenched by Cu²⁺ via the inner filter effect (IFE), allowing quantitative analysis with superior sensitivity compared to existing methods. By adding bacterial cellulose (BC) as a solid support, aggregation-induced fluorescence quenching was effectively reduced, and sensor robustness and portability were improved. Through smartphone-based colorimetric analysis, the Y-CDs@BCM sensor enabled rapid, visual interpretation of Cu²⁺ detection (within 1 min). Furthermore, cell viability and in vivo assays confirmed the biocompatibility of Y-CDs, indicating their suitability for biological imaging. This work presents an environmentally friendly, reliable, and practical method for on-site Cu²⁺ monitoring, emphasizing its broad application potential in food safety control and environmental analysis. Full article

(This article belongs to the Special Issue Applications of Fluorescent Sensors in Food and Environment)

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22 pages, 1802 KB

Open AccessArticle

Proteolytic Bacillus sp. Isolation and Identification from Tannery Alkaline Baths

by Manuela Lageiro, Fernanda Simões, Nuno Alvarenga and Alberto Reis

Molecules 2025, 30(17), 3632; https://doi.org/10.3390/molecules30173632 - 5 Sep 2025

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Abstract

The application of microbial alkaline proteases holds significant potential for eco-sustainable industrial processes by reducing chemical usage and lowering the costs of effluent treatment. In the search for novel proteases with industrial relevance, several microbial strains were isolated from alkaline baths of the [...] Read more.

The application of microbial alkaline proteases holds significant potential for eco-sustainable industrial processes by reducing chemical usage and lowering the costs of effluent treatment. In the search for novel proteases with industrial relevance, several microbial strains were isolated from alkaline baths of the Portuguese tannery agroindustry. The most promising protease-producing strains were selected for identification and further study. Two isolates demonstrated the highest proteolytic activity, reaching 0.51 ± 0.01 U mL⁻¹ and 0.70 ± 0.01 U mL⁻¹ after 7.5 h of submerged cultivation in nutrient broth. Based on API biochemical tests, molecular biology techniques, and GC-FAME analysis of membrane lipids, the isolates were identified as Bacillus subtilis and incorporated into INIAV’s collection of industrial microbial cultures as B. subtilis CCMI 1253 (BMR2) and B. subtilis CCMI 1254 (BMR1). The most promising protease producer, B. subtilis CCMI 1253 (BMR2), exhibited a maximum specific growth rate of 0.88 ± 0.10 h⁻¹. The proteases produced exhibited good extracellular proteolytic activity, with adaptability to industrial conditions, indicating their suitability for agroindustry applications such as leather making, detergent formulations and the treatment of effluents and protein residues. The results support the potential of microbial proteases as valuable tools in the bioeconomy and green chemistry. Full article

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

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25 pages, 3597 KB

Open AccessArticle

Morphology-Dependent Transformation of Dicalcium Phosphate Dihydrate (DCPD) to Octacalcium Phosphate (OCP) and Its Stability in Simulated Physiological Fluids

by Daniela Chávez-Herrera, Estefanía Rangel-Villanueva, Mercedes Salazar-Hernández, Alfonso Talavera-Lopez, Alba N. Ardila A., Rosa Hernández-Soto, Oscar Joaquín Solis-Marcial and Jose A. Hernández

Molecules 2025, 30(17), 3631; https://doi.org/10.3390/molecules30173631 - 5 Sep 2025

Viewed by 817

Abstract

Calcium phosphate (CaP) materials are biocompatible and non-toxic to the body. However, they lack biointegration, exhibit a low resorption rate and can cause fibrous encapsulation throughout the implant material. A promising approach for dental or orthopedic regeneration is the use of dicalcium phosphate [...] Read more.

Calcium phosphate (CaP) materials are biocompatible and non-toxic to the body. However, they lack biointegration, exhibit a low resorption rate and can cause fibrous encapsulation throughout the implant material. A promising approach for dental or orthopedic regeneration is the use of dicalcium phosphate dihydrate (DCPD) and octacalcium phosphate (OCP), as they are well-suited to bone components. From a novel perspective, these apatites can be used as drug carriers for individuals with low tolerance to common excipients. In this study, the transformation of DCPD into different morphologies in DMEM was investigated using an induced dissolution and reprecipitation reaction solution. The DCPD transformation time was observed to be morphology-dependent and can occur between 48 and 168 h. In the interaction with simulated body fluid (SBF), simulated gastric fluid (SGF) and a combination of both (BFS/SGF), a higher mass loss was observed in SGF (~80%) than in the other fluids (~35%). The structural changes presented in DCPD and OCP before and after immersion in physiological fluids were analyzed by ATR-FTIR, SEM, XRD and EDS. The obtained OCP showed low stability in SGF compared to SBF and SBF/SGF, which indicates that it may be a suitable candidate for drug delivery in the digestive tract. Full article

(This article belongs to the Special Issue Design, Modifications, and Medical Application of Polymer-Based Materials)

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23 pages, 620 KB

Open AccessReview

Comparative Analysis of Biochemical and Cellular Assay Conditions and the Need for a Buffer That Mimics Cytoplasmic Environments

by George Kontopidis and Iason-Spyridon Patergiannakis

Molecules 2025, 30(17), 3630; https://doi.org/10.3390/molecules30173630 - 5 Sep 2025

Viewed by 713

Abstract

The assessment of a ligand’s activity is typically established by measuring its binding affinity in a biochemical assay, often expressed as K_a or K_d values. Further validation of its biological activity is achieved through cellular assays. There is frequently an inconsistency [...] Read more.

The assessment of a ligand’s activity is typically established by measuring its binding affinity in a biochemical assay, often expressed as K_a or K_d values. Further validation of its biological activity is achieved through cellular assays. There is frequently an inconsistency between the activity values obtained from those assays, which could delay research progress as well as drug development. Factors such as the permeability, solubility, specificity, and stability of active compounds are usually held responsible for this discrepancy. Even when these values are known, inconsistencies in activity measurements remain challenging to explain. This is not surprising since intracellular physicochemical conditions are undoubtedly different from the simplified conditions used in most in vitro biochemical assays. It is therefore reasonable to assume that these differences would be minimized if biochemical measurements were performed under conditions that more accurately mimic the intracellular environment. These physicochemical conditions can alter the K_d values. While the cellular environment has been extensively studied for decades, more recent efforts have focused on obtaining equilibrium and kinetic data directly from in-cell environments. Clarifying molecular crowding, salt composition, and lipophilic parameters inside the cell and thus their effect on molecular equilibrium is a crucial step toward replicating the intracellular environment. Full article

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14 pages, 948 KB

Open AccessArticle

Ni-Catalyzed [2 + 2 + 2] Cycloaddition via the Capture of Azametallacyclopentadienes with Allyl Boronate: Facile Access to Fused Pyridine Derivatives

by Kesi Du, Tao Zhu, Guangyu Li, Taohong Shi, Chunsheng Li, Siting Hu, Ruiran Gao, Zhao-Yang Wang and Jiuzhong Huang

Molecules 2025, 30(17), 3629; https://doi.org/10.3390/molecules30173629 - 5 Sep 2025

Viewed by 752

Abstract

An unprecedented nickel-catalyzed [2 + 2 + 2] cycloaddition that enables efficient construction of fused pyridine frameworks with allyl boronate was reported. This transformation is proposed to occur through a mechanism involving aza-nickelacyclopentadiene intermediates, wherein the boryl group of the allyl boronate plays [...] Read more.

An unprecedented nickel-catalyzed [2 + 2 + 2] cycloaddition that enables efficient construction of fused pyridine frameworks with allyl boronate was reported. This transformation is proposed to occur through a mechanism involving aza-nickelacyclopentadiene intermediates, wherein the boryl group of the allyl boronate plays a critical role in enabling the following cyclization via the control experiments. This work not only expands the structural diversity accessible via transition-metal-catalyzed [2 + 2 + 2] cycloadditions but also showcases the untapped potential of unsaturated substrates in cycloaddition reactions. Full article

(This article belongs to the Special Issue Advances in Organic Synthesis in Pharmaceuticals, Agrochemicals and Materials)

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