Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (1,202)

Search Parameters:
Keywords = Dynamic NMR

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
19 pages, 4839 KiB  
Article
Corrosion Inhibition of C38 Steel in 1 M HCl Using Benzoxazole-2-Thione: Electrochemical, SEM-EDX, and Theoretical Studies
by Mohamed Omari, Khalid Bouiti, Said Jebbari, Nabil Lahrache, Ali Barhoumi, Najoua Labjar, Souad El Hajjaji, Mahado Said-Ahmed, Mounim Lebrini, Hamid Nasrellah, Mohammed El Idrissi and Abdessamad Tounsi
Metals 2025, 15(7), 810; https://doi.org/10.3390/met15070810 - 19 Jul 2025
Viewed by 352
Abstract
This study explores the corrosion inhibition of C38 steel in a 1 M hydrochloric acid (HCl) solution using a novel benzoxazole-2-thione compound. The inhibitor was synthesized and structurally characterized by both 1H NMR (DMSO-d6/TMS) and 13C NMR spectroscopy. Electrochemical [...] Read more.
This study explores the corrosion inhibition of C38 steel in a 1 M hydrochloric acid (HCl) solution using a novel benzoxazole-2-thione compound. The inhibitor was synthesized and structurally characterized by both 1H NMR (DMSO-d6/TMS) and 13C NMR spectroscopy. Electrochemical techniques, including Tafel polarization and electrochemical impedance spectroscopy, were employed to evaluate the inhibition performance. The results indicate that the benzoxazole-2-thione significantly reduces the corrosion rate, achieving a maximum inhibition efficiency of 95.25% at a concentration of 10−4 M. To gain deeper insights into the inhibition mechanism, theoretical methods such as density functional theory, Monte Carlo simulations, and molecular dynamics were applied to investigate the adsorption behavior of the compound on the steel surface. The adsorption process follows the Langmuir isotherm model, suggesting the coexistence of physisorption and chemisorption interactions. Surface morphology and elemental composition analyses using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX) confirm the formation of a protective inhibitor film on the steel surface. Full article
Show Figures

Figure 1

17 pages, 2173 KiB  
Article
Unveiling the Solvent Effect: DMSO Interaction with Human Nerve Growth Factor and Its Implications for Drug Discovery
by Francesca Paoletti, Tjaša Goričan, Alberto Cassetta, Jože Grdadolnik, Mykola Toporash, Doriano Lamba, Simona Golič Grdadolnik and Sonia Covaceuszach
Molecules 2025, 30(14), 3030; https://doi.org/10.3390/molecules30143030 - 19 Jul 2025
Viewed by 203
Abstract
Background: The Nerve Growth Factor (NGF) is essential for neuronal survival and function and represents a key therapeutic target for pain and inflammation-related disorders, as well as for neurodegenerative diseases. Small-molecule antagonists of human NGF (hNGF) offer advantages over monoclonal antibodies, including oral [...] Read more.
Background: The Nerve Growth Factor (NGF) is essential for neuronal survival and function and represents a key therapeutic target for pain and inflammation-related disorders, as well as for neurodegenerative diseases. Small-molecule antagonists of human NGF (hNGF) offer advantages over monoclonal antibodies, including oral availability and reduced immunogenicity. However, their development is often hindered by solubility challenges, necessitating the use of solvents like dimethyl sulfoxide (DMSO). This study investigates whether DMSO directly interacts with hNGF and affects its receptor-binding properties. Methods: Integrative/hybrid computational and experimental biophysical approaches were used to assess DMSO-NGF interaction by combining machine-learning tools and Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared (FT-IR) spectroscopy, Differential Scanning Fluorimetry (DSF) and Grating-Coupled Interferometry (GCI). These techniques evaluated binding affinity, conformational stability, and receptor-binding dynamics. Results: Our findings demonstrate that DMSO binds hNGF with low affinity in a specific yet non-disruptive manner. Importantly, DMSO does not induce significant conformational changes in hNGF nor affect its interactions with its receptors. Conclusions: These results highlight the importance of considering solvent–protein interactions in drug discovery, as these low-affinity yet specific interactions can affect experimental outcomes and potentially alter the small molecules binding to the target proteins. By characterizing DMSO-NGF interactions, this study provides valuable insights for the development of NGF-targeting small molecules, supporting their potential as effective alternatives to monoclonal antibodies for treating pain, inflammation, and neurodegenerative diseases. Full article
Show Figures

Graphical abstract

15 pages, 4059 KiB  
Article
Surface Fluorination for the Stabilization in Air of Garnet-Type Oxide Solid Electrolyte for Lithium Ion Battery
by Michael Herraiz, Saida Moumen, Kevin Lemoine, Laurent Jouffret, Katia Guérin, Elodie Petit, Nathalie Gaillard, Laure Bertry, Reka Toth, Thierry Le Mercier, Valérie Buissette and Marc Dubois
Batteries 2025, 11(7), 268; https://doi.org/10.3390/batteries11070268 - 16 Jul 2025
Viewed by 178
Abstract
After reviewing the state of the art of the fluorination of inorganic solid electrolytes, an application of gas/solid fluorination is given and how it can be processed. Garnet-type oxide has been chosen. These oxides with an ideal structure of chemical formula A3 [...] Read more.
After reviewing the state of the art of the fluorination of inorganic solid electrolytes, an application of gas/solid fluorination is given and how it can be processed. Garnet-type oxide has been chosen. These oxides with an ideal structure of chemical formula A3B2(XO4)3 are mainly known for their magnetic and dielectric properties. Certain garnets may have a high enough Li+ ionic conductivity to be used as solid electrolyte of lithium ion battery. The surface of LLZO may be changed in contact with the moisture and CO2 present in the atmosphere that results in a change of the conductivity at the interface of the solid. LiOH and/or lithium carbonate are formed at the surface of the garnet particles. In order to allow for handling and storage under normal conditions of this solid electrolyte, surface fluorination was performed using elemental fluorine. When controlled using mild conditions (temperature lower or equal to 200 °C, either in static or dynamic mode), the addition of fluorine atoms to LLZO with Li6,4Al0,2La3Zr2O12 composition is limited to the surface, forming a covering layer of lithium fluoride LiF. The effect of the fluorination was evidenced by IR, Raman, and NMR spectroscopies. If present in the pristine LLZO powder, then the carbonate groups disappear. More interestingly, contrary to the pristine LLZO, the contents of these groups are drastically reduced even after storage in air up to 45 days when the powder is covered with the LiF layer. Surface fluorination could be applied to other solid electrolytes that are air sensitive. Full article
Show Figures

Figure 1

17 pages, 3448 KiB  
Article
Entry Inhibitors of SARS-CoV-2 Targeting the Transmembrane Domain of the Spike Protein
by Kristin V. Lyles, Shannon Stone, Priti Singh, Lila D. Patterson, Janhavi Natekar, Heather Pathak, Rohit K. Varshnaya, Amany Elsharkawy, Dongning Liu, Shubham Bansal, Oluwafoyinsola O. Faniyi, Sijia Tang, Xiaoxiao Yang, Nagaraju Mulpuri, Donald Hamelberg, Congbao Kang, Binghe Wang, Mukesh Kumar and Ming Luo
Viruses 2025, 17(7), 989; https://doi.org/10.3390/v17070989 - 16 Jul 2025
Viewed by 408
Abstract
Despite current vaccines and therapeutics targeting SARS-CoV-2, the causative agent of the COVID-19 pandemic, cases remain high causing a burden on health care systems. Spike-protein mediated membrane fusion of SARS-CoV-2 is a critical step in viral entry. Herein, we describe entry inhibitors identified [...] Read more.
Despite current vaccines and therapeutics targeting SARS-CoV-2, the causative agent of the COVID-19 pandemic, cases remain high causing a burden on health care systems. Spike-protein mediated membrane fusion of SARS-CoV-2 is a critical step in viral entry. Herein, we describe entry inhibitors identified by first screening a library of about 160 compounds and then analogue synthesis. Specifically, compound 261 was found to inhibit SARS-CoV-2 infection in a tissue model with IC50 of 0.3 µM. Using NMR, we found that 261 interacts with key residues in the aromatic-rich region of the spike protein directly next to the transmembrane domain. Molecular dynamic simulations of the 261 binding pocket in the spike protein was also mapped to the transmembrane domain, consistent with NMR findings. The amino acids in the binding site are conserved among different coronaviruses known to infect humans; therefore, inhibitors targeting this conserved binding site could be a useful addition to current therapeutics and may have pan-coronavirus antiviral activities. Full article
Show Figures

Figure 1

17 pages, 3065 KiB  
Article
Matrix Metalloproteinase-2-Responsive Peptide-Modified Cleavable PEGylated Liposomes for Paclitaxel Delivery
by Xingyu Zhao and Yinghuan Li
Pharmaceuticals 2025, 18(7), 1042; https://doi.org/10.3390/ph18071042 - 15 Jul 2025
Viewed by 389
Abstract
Background/Objectives: PEGylated liposomes are widely recognized for their biocompatibility and capacity to extend systemic circulation via “stealth” properties. However, the PEG corona often limits tumor penetration and cellular internalization. Targeting matrix metalloproteinase-2 (MMP-2), frequently upregulated in breast cancer stroma, presents an opportunity [...] Read more.
Background/Objectives: PEGylated liposomes are widely recognized for their biocompatibility and capacity to extend systemic circulation via “stealth” properties. However, the PEG corona often limits tumor penetration and cellular internalization. Targeting matrix metalloproteinase-2 (MMP-2), frequently upregulated in breast cancer stroma, presents an opportunity to enhance tissue-specific drug delivery. In this study, we engineered MMP-2-responsive GPLGVRG peptide-modified cleavable PEGylated liposomes for targeted paclitaxel (PTX) delivery. Methods: Molecular docking simulations employed the MMP-2 crystal structure (PDB ID: 7XJO) to assess GPLGVRG peptide binding affinity. A cleavable, enzyme-sensitive peptide-PEG conjugate (Chol-PEG2K-GPLGVRG-PEG5K) was synthesized via small-molecule liquid-phase synthesis and characterized by 1H NMR and MALDI-TOF MS. Liposomes incorporating this conjugate (S-Peps-PEG5K) were formulated to evaluate whether MMP-2-mediated peptide degradation triggers detachment of long-chain PEG moieties, thereby enhancing internalization by 4T1 breast cancer cells. Additionally, the effects of tumor microenvironmental pH (~6.5) and MMP-2 concentration on drug release dynamics were investigated. Results: Molecular docking revealed robust GPLGVRG-MMP-2 interactions, yielding a binding energy of −7.1 kcal/mol. The peptide formed hydrogen bonds with MMP-2 residues Tyr A:23 and Arg A:53 (bond lengths: 2.4–2.5 Å) and engaged in hydrophobic contacts, confirming MMP-2 as the primary recognition site. Formulations containing 5 mol% Chol-PEG2K-GPLGVRG-PEG5K combined with 0.15 µg/mL MMP-2 (S-Peps-PEG5K +MMP) exhibited superior internalization efficiency and significantly reduced clonogenic survival compared to controls. Notably, acidic pH (~6.5) induced MMP-2-mediated cleavage of the GPLGVRG peptide, accelerating S-Peps-PEG5K dissociation and facilitating drug release. Conclusions: MMP-2-responsive, cleavable PEGylated liposomes markedly improve PTX accumulation and controlled release at tumor sites by dynamically modulating their stealth properties, offering a promising strategy to enhance chemotherapy efficacy in breast cancer. Full article
Show Figures

Graphical abstract

20 pages, 2317 KiB  
Article
Multifunctional Amphiphilic Biocidal Copolymers Based on N-(3-(Dimethylamino)propyl)methacrylamide Exhibiting pH-, Thermo-, and CO2-Sensitivity
by Maria Filomeni Koutsougera, Spyridoula Adamopoulou, Denisa Druvari, Alexios Vlamis-Gardikas, Zacharoula Iatridi and Georgios Bokias
Polymers 2025, 17(14), 1896; https://doi.org/10.3390/polym17141896 - 9 Jul 2025
Viewed by 373
Abstract
Because of their potential “smart” applications, multifunctional stimuli-responsive polymers are gaining increasing scientific interest. The present work explores the possibility of developing such materials based on the hydrolytically stable N-3-dimethylamino propyl methacrylamide), DMAPMA. To this end, the properties in aqueous solution of the [...] Read more.
Because of their potential “smart” applications, multifunctional stimuli-responsive polymers are gaining increasing scientific interest. The present work explores the possibility of developing such materials based on the hydrolytically stable N-3-dimethylamino propyl methacrylamide), DMAPMA. To this end, the properties in aqueous solution of the homopolymer PDMAPMA and copolymers P(DMAPMA-co-MMAx) of DMAPMA with the hydrophobic monomer methyl methacrylate, MMA, were explored. Two copolymers were prepared with a molar content x = 20% and 35%, as determined by Proton Nuclear Magnetic Resonance (1H NMR). Turbidimetry studies revealed that, in contrast to the homopolymer exhibiting a lower critical solution temperature (LCST) behavior only at pH 14 in the absence of salt, the LCST of the copolymers covers a wider pH range (pH > 8.5) and can be tuned within the whole temperature range studied (from room temperature up to ~70 °C) through the use of salt. The copolymers self-assemble in water above a critical aggregation Concentration (CAC), as determined by Nile Red probing, and form nanostructures with a size of ~15 nm (for P(DMAPMA-co-MMA35)), as revealed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The combination of turbidimetry with 1H NMR and automatic total organic carbon/total nitrogen (TOC/TN) results revealed the potential of the copolymers as visual CO2 sensors. Finally, the alkylation of the copolymers with dodecyl groups lead to cationic amphiphilic materials with an order of magnitude lower CAC (as compared to the unmodified precursor), effectively stabilized in water as larger aggregates (~200 nm) over a wide temperature range, due to their increased ζ potential (+15 mV). Such alkylated products show promising biocidal properties against microorganisms such as Escherichia coli and Staphylococcus aureus. Full article
(This article belongs to the Special Issue Development and Innovation of Stimuli-Responsive Polymers)
Show Figures

Figure 1

21 pages, 6308 KiB  
Article
Revealing Serotonin Derivatives in Safflower Seed Meal as Potential Anti-Ulcerative Colitis Drugs: In Vitro and Computational Evidence
by Liang Zhang, Md Hasan Ali, Chao Jiang, Furong Fan, Furong Zhu, Yating Lu, Mengwei Jia, Haipeng Yin, Jianwang Wei, Dongsen Wu, Shenghui Chu and Min Liu
Molecules 2025, 30(13), 2886; https://doi.org/10.3390/molecules30132886 - 7 Jul 2025
Viewed by 315
Abstract
This study evaluated the in vitro anti-inflammatory activity of serotonin derivatives from safflower seed powder and elucidated their mechanism against ulcerative colitis using network pharmacology. Compounds were extracted and purified via silica gel column chromatography, Sephadex LH-20 and semi-preparative HPLC. Structural characterization employed [...] Read more.
This study evaluated the in vitro anti-inflammatory activity of serotonin derivatives from safflower seed powder and elucidated their mechanism against ulcerative colitis using network pharmacology. Compounds were extracted and purified via silica gel column chromatography, Sephadex LH-20 and semi-preparative HPLC. Structural characterization employed NMR and UPLC-Q-TOF-MS/MS with literature comparisons. Anti-inflammatory efficacy was assessed in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Network pharmacology predicted targets, molecular docking analyzed binding interactions and molecular dynamics simulations assessed complex stability. Eleven serotonin derivatives were isolated; N-trans-Feruloyl-3,5-dihydroxyindolin-2-one (1) and Bufoserotonin A (2) were identified in safflower seed meal for the first time. Compounds 1, 37 and 10 significantly reduced inflammatory factors, with N-feruloyl serotonin (4, FS) showing the strongest activity. Mechanistic studies revealed FS targets key molecules (STAT3, EGFR, ESR1, PTGS2, NF-κB1, and JUN), modulating PI3K-Akt, MAPK and cancer-related pathways. Molecular dynamics simulations confirmed FS-EGFR complex stability. Thus, two novel derivatives were isolated and FS demonstrated significant anti-inflammatory and potential anti-ulcerative colitis effects through multi-target, multi-pathway synergy, providing a foundation for developing safflower seed meal therapeutics. Full article
Show Figures

Figure 1

26 pages, 808 KiB  
Review
A Review of Formulation Strategies for Cyclodextrin-Enhanced Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs)
by Tarek Alloush and Burcu Demiralp
Int. J. Mol. Sci. 2025, 26(13), 6509; https://doi.org/10.3390/ijms26136509 - 6 Jul 2025
Viewed by 785
Abstract
The advancement of efficient drug delivery systems continues to pose a significant problem in pharmaceutical sciences, especially for compounds with limited water solubility. Lipid-based systems, including solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), have emerged as viable options owing to their [...] Read more.
The advancement of efficient drug delivery systems continues to pose a significant problem in pharmaceutical sciences, especially for compounds with limited water solubility. Lipid-based systems, including solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), have emerged as viable options owing to their biocompatibility, capability to safeguard labile chemicals, and potential for prolonged release. Nonetheless, the encapsulation efficiency (EE) and release dynamics of these carriers can be enhanced by including cyclodextrins (CDs)—cyclic oligosaccharides recognized for their ability to form inclusion complexes with hydrophobic compounds. This article offers an extensive analysis of CD-modified SLNs and NLCs as multifunctional drug delivery systems. The article analyses the fundamental principles of these systems, highlighting the pre-complexation of the drug with cyclodextrins before lipid incorporation, co-encapsulation techniques, and surface adsorption after formulation. Attention is concentrated on the physicochemical interactions between cyclodextrins and lipid matrices, which influence essential factors such as particle size, encapsulation efficiency, and colloidal stability. The review includes characterization techniques, such as particle size analysis, zeta potential measurement, drug release studies, and Fourier-transform infrared spectroscopy (FT-IR)/Nuclear Magnetic Resonance (NMR) analyses. The study highlights the application of these systems across many routes of administration, including oral, topical, and mucosal, illustrating their adaptability and potential for targeted delivery. The review outlines current formulation challenges, including stability issues, drug leakage, and scalability concerns, and proposes solutions through advanced approaches, such as stimuli-responsive release mechanisms and computer modeling for system optimization. The study emphasizes the importance of regulatory aspects and outlines future directions in the development of CD-lipid hybrid nanocarriers, showcasing its potential to revolutionize the delivery of poorly soluble drugs. Full article
(This article belongs to the Special Issue Research on Cyclodextrin)
Show Figures

Graphical abstract

12 pages, 1751 KiB  
Article
Studies on Molecular Dynamics Simulation and Reaction Mechanism for Methane Adsorption in Long-Flame Coal Modified by Cyclical Microwave Treatment
by Guofei Zhao, Yongbo Cai, Tianbai Zhou, Guangtong Yang, Long Wang, Liankun Zhang, Yuefang Wang and Xiaoyu Zhang
Processes 2025, 13(7), 2134; https://doi.org/10.3390/pr13072134 - 4 Jul 2025
Viewed by 307
Abstract
A quantitative characterization of the change in coal molecular structures with different cyclical microwave modification parameters and a better understanding of the reaction mechanism of the modification are of great significance for the commercial extraction of coal bed methane (CBM). Therefore, long-flame coal [...] Read more.
A quantitative characterization of the change in coal molecular structures with different cyclical microwave modification parameters and a better understanding of the reaction mechanism of the modification are of great significance for the commercial extraction of coal bed methane (CBM). Therefore, long-flame coal samples obtained from the Ordos Basin, China, were modified by microwave radiation with different times, and the long-flame coal molecular structure parameters were determined by solid-state 13C nuclear magnetic resonance (ss13C NMR), Fourier transform infrared (FTIR) spectrometry, and X-ray photoelectron spectrometry (XPS). Atomistic representations of the raw long-flame coal molecular model and modified long-flame coal molecular models were established. The temperature rise, pore volume increase, mineral removal, and functional group changes after the modification have a negative effect on methane adsorption. After the modification, the decrease in surface area of the micropores reduced the adsorption site of methane in coal. As a result, the methane adsorption amount decreased linearly with the decreasing surface area. The CH4 adsorption isotherms of the long-flame models were dynamically simulated and analyzed. The results of this study can prove that after multiple cycles of microwave modifications, the functional groups in long-flame coal were fractured, and the number of micropores was reduced, which effectively decreased the methane adsorption performance in long-flame coal seams, thereby promoting methane extraction. Microwave modification is a promising method for enhancing CBM recovery. Full article
Show Figures

Figure 1

16 pages, 1229 KiB  
Article
Nonlinear Hydrogen Bond Network in Small Water Clusters: Combining NMR, DFT, FT-IR, and EIS Research
by Ignat Ignatov, Yordan G. Marinov, Paunka Vassileva, Georgi Gluhchev, Ludmila A. Pesotskaya, Ivan P. Jordanov and Mario T. Iliev
Symmetry 2025, 17(7), 1062; https://doi.org/10.3390/sym17071062 - 4 Jul 2025
Cited by 1 | Viewed by 432
Abstract
Water’s unique physicochemical properties arise from its dynamic hydrogen-bonding network, yet the precise molecular threshold at which these cooperative behaviors emerge remains a key question. This study employed nuclear magnetic resonance (NMR) spectroscopy and density functional theory (DFT) calculations to investigate the evolution [...] Read more.
Water’s unique physicochemical properties arise from its dynamic hydrogen-bonding network, yet the precise molecular threshold at which these cooperative behaviors emerge remains a key question. This study employed nuclear magnetic resonance (NMR) spectroscopy and density functional theory (DFT) calculations to investigate the evolution of hydrogen bonding strength in small water clusters, ranging from dimers to pentamers. The observed exponential increase in NMR chemical shift up to the pentamer reflects growing hydrogen bond cooperativity, identifying the (H2O)5 cluster as a critical structural and energetic threshold. At this size, the network achieves sufficient connectivity to support key bulk-like phenomena such as proton transfer and dielectric relaxation. These conclusions were corroborated by complementary FT-IR and electrochemical impedance spectroscopy (EIS) measurements of bulk water. Our results position the water pentamer as the molecular onset of emergent solvent behavior, effectively bridging the divide between discrete clusters and the macroscopic properties of liquid water. Full article
(This article belongs to the Section Chemistry: Symmetry/Asymmetry)
Show Figures

Figure 1

22 pages, 3243 KiB  
Article
Development of a Continuous Extrusion Process for Alginate Biopolymer Films for Sustainable Applications
by Zahra Eslami, Saïd Elkoun, Miraidin Mirzapour and Mathieu Robert
Polymers 2025, 17(13), 1818; https://doi.org/10.3390/polym17131818 - 29 Jun 2025
Viewed by 553
Abstract
This study presents a novel method for producing extrudable alginate-based films using continuous thermo-mechanical mixing, providing a scalable alternative to conventional solvent-casting techniques. The effects of glycerol concentration (30–50 wt%) and processing temperature (110–120 °C) on the films’ thermal, mechanical, and structural properties [...] Read more.
This study presents a novel method for producing extrudable alginate-based films using continuous thermo-mechanical mixing, providing a scalable alternative to conventional solvent-casting techniques. The effects of glycerol concentration (30–50 wt%) and processing temperature (110–120 °C) on the films’ thermal, mechanical, and structural properties were systematically investigated. Structural characterization was performed using 1H NMR and FT-IR, and thermal transitions were analyzed via DSC (Differential Scanning Calorimetry) and DMA (Dynamic Mechanical Analysis). The glass transition temperature (Tg) of the alginate/glycerol/water system was modeled using the Gordon–Taylor equation. Glycerol incorporation significantly reduced Tg—by up to 76 °C with 40 wt% glycerol—and enhanced ductility and toughness, reaching 3.26 MJ/m3 at the optimal level. The influence of processing temperature was found to depend on plasticizer content: at lower glycerol levels, elevated temperatures decreased Tg and elongation at break, likely due to thermal degradation. However, films with higher glycerol content retained stable mechanical and thermal behavior across both temperature profiles. This work is among the first to explore how processing temperature affects extruded, plasticized pure alginate films. The findings provide key insights into the formulation and scalable production of bio-based packaging materials, highlighting the importance of optimizing both plasticizer concentration and processing parameters. Full article
(This article belongs to the Special Issue Recent Advances and Applications of Polymer Nanocomposites)
Show Figures

Graphical abstract

31 pages, 7317 KiB  
Article
Synthesis, Biological Evaluation, and In Silico Characterization of Novel Imidazothiadiazole–Chalcone Hybrids as Multi-Target Enzyme Inhibitors
by Hakan Alici, Senol Topuz, Kadir Demir, Parham Taslimi and Hakan Tahtaci
Pharmaceuticals 2025, 18(7), 962; https://doi.org/10.3390/ph18070962 - 26 Jun 2025
Viewed by 494
Abstract
Background/Objectives: The need for dual-targeted enzyme inhibitors is critical in addressing complex diseases like Alzheimer’s and glaucoma. Imidazothiadiazole and chalcone moieties are known for diverse bioactivities. This study aimed to develop novel imidazothiadiazole–chalcone hybrids as potential inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and [...] Read more.
Background/Objectives: The need for dual-targeted enzyme inhibitors is critical in addressing complex diseases like Alzheimer’s and glaucoma. Imidazothiadiazole and chalcone moieties are known for diverse bioactivities. This study aimed to develop novel imidazothiadiazole–chalcone hybrids as potential inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and human carbonic anhydrase isoforms (hCAs), specifically hCA I and hCA II. Methods: Four hybrid molecules (8a–8d) were synthesized and structurally confirmed via 1H NMR, 13C NMR, FT-IR, MS, and elemental analysis techniques. Their enzyme inhibitory activities were assessed using Ellman’s and Verpoorte’s methods. Molecular docking and 100 ns molecular dynamics (MD) simulations were conducted to examine binding interactions. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties were predicted using the pkCSM platform. Results: All compounds showed strong enzyme inhibition: AChE (Ki: 3.86–11.35 nM), BChE (Ki: 1.01–1.78 nM), hCA I (Ki: 45.13–81.24 nM), and hCA II (Ki: 36.08–52.45 nM). Docking analyses confirmed favorable binding, particularly with active-site residues. MD simulations demonstrated stable interactions throughout 100 ns. Compound 8a exhibited the highest cholinesterase inhibition, while compounds 8d and 8c were the most potent against hCA I and hCA II, respectively. The ADMET results showed high absorption and acceptable safety, with mild mutagenicity or cardiotoxicity concerns in select compounds. Conclusions: These findings suggest that imidazothiadiazole–chalcone hybrids are promising multi-target enzyme inhibitors. Their potent activity, structural stability, and pharmacokinetic potential support their further development for therapeutic use in neurodegenerative and ocular diseases. Full article
Show Figures

Graphical abstract

24 pages, 6370 KiB  
Article
Influence of Peptide Conjugation Sites on Lunatin–Alumina Nanoparticles: Implications for Membrane Interaction and Antimicrobial Activity
by Carolina Silva Ferreira, Lívia Mara Fontes Costa, Lúcio Otávio Nunes, Kelton Rodrigues de Souza, Giovanna Paula Araújo, Evgeniy S. Salnikov, Kelly Cristina Kato, Helen Rodrigues Martins, Adriano Monteiro de Castro Pimenta, Jarbas Magalhães Resende, Burkhard Bechinger and Rodrigo Moreira Verly
Pharmaceuticals 2025, 18(7), 952; https://doi.org/10.3390/ph18070952 - 24 Jun 2025
Viewed by 448
Abstract
Background/Objectives: The increasing prevalence of multidrug-resistant bacteria presents a major global health challenge, prompting a search for innovative antimicrobial strategies. This study aimed to develop and evaluate a novel nanobiostructure combining alumina nanoparticles (NPs) with the antimicrobial peptide lunatin-1 (Lun-1), forming peptide-functionalized nanofilaments. [...] Read more.
Background/Objectives: The increasing prevalence of multidrug-resistant bacteria presents a major global health challenge, prompting a search for innovative antimicrobial strategies. This study aimed to develop and evaluate a novel nanobiostructure combining alumina nanoparticles (NPs) with the antimicrobial peptide lunatin-1 (Lun-1), forming peptide-functionalized nanofilaments. The main objective was to investigate how the site of peptide functionalization (C-terminal vs. N-terminal) affects membrane interactions and antibacterial activity. Methods: NP–peptide conjugates were synthesized via covalent bonding between lun-1 and alumina NP and characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), zeta potential analysis, dynamic light scattering (DLS), Fourier-transform infrared (FTIR), and solid-state 13C NMR. Antibacterial activities were assessed against different Gram-positive and Gram-negative strains. Biophysical analyses, including circular dichroism (CD), isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC), and solid-state 2H NMR, were employed to evaluate peptide–membrane interactions in the presence of membrane-mimetic vesicles composed of POPC:POPG (3:1) and DMPC:DMPG (3:1). Results: Characterization confirmed the successful formation of NP–peptide nanofilaments. Functionalization at the N-terminal significantly influenced both antibacterial activity and peptide conformation compared to C-terminal attachment. Biophysical data demonstrated stronger membrane interaction and greater membrane disruption when lun-1 was conjugated at the N-terminal. Conclusions: The site of peptide conjugation plays a crucial role in modulating the biological and biophysical properties of NP–lunatin-1 conjugates. C-terminal attachment of lunatin-1 retains both membrane interaction and antibacterial efficacy, making it a promising strategy for the design of peptide-based nanotherapeutics targeting resistant pathogens. Full article
Show Figures

Figure 1

28 pages, 4548 KiB  
Article
New Tools in Heavy Metal Detection: Synthesis, Spectroscopic, and Quantum Chemical Characterization of Selected Water-Soluble Styryl Derivatives of Quinoline and 1,10-Phenanthroline
by Jacek E. Nycz, Jolanta Kolińska, Nataliya Karaush-Karmazin, Tieqiao Chen, Maria Książek and Joachim Kusz
Molecules 2025, 30(12), 2659; https://doi.org/10.3390/molecules30122659 - 19 Jun 2025
Viewed by 592
Abstract
A series of water-soluble molecules based on 8-isopropyl-2-methyl-5-nitroquinoline and 1,10-phenanthroline core were designed by introducing a π-conjugated bridge, vinyl unit –CH=CH–. We present the selective conversion of methyl groups located on the C2 and C9 positions in the constitution of selected quinoline or [...] Read more.
A series of water-soluble molecules based on 8-isopropyl-2-methyl-5-nitroquinoline and 1,10-phenanthroline core were designed by introducing a π-conjugated bridge, vinyl unit –CH=CH–. We present the selective conversion of methyl groups located on the C2 and C9 positions in the constitution of selected quinoline or 1,10-phenanthroline derivatives, respectively, into vinyl (or styryl) products by applying Perkin condensation. The two groups of ligands differ in the presence of one or two arms. The structure of the molecule ((1E,1′E)-(1,10-phenanthroline-2,9-diyl)bis(ethene-2,1-diyl))bis(benzene-4,1,3-triyl) tetraacetate was determined by single-crystal X-ray diffraction measurements. The X-ray, NMR, and DFT computational studies indicate the influence of rotation (rotamers) on the physical properties of studied styryl molecules. The results show that the styryl molecules with the vinyl unit –CH=CH– exhibit significant static and dynamic hyperpolarizabilities. Quantum chemical calculations using density functional theory and B3LYP/6-311++G(d,p) with Grimme’s dispersion correction approach predict the existence and relative stability of different spatial cis(Z)- and trans(E)-conformers of styryl derivatives of quinoline and 1,10-phenanthroline, which exhibit different electronic distribution and conjugation within the molecular skeleton, dipole moments, and steric interactions, leading to variations in their photophysical behavior and various applications. Our studies indicate that the rotation and isomerization of aryl groups can significantly influence the electronic and optical properties of π-conjugated systems, such as vinyl units (–CH=CH–). The rotation of aryl groups around the single bond that connects them to the vinyl unit can lead to changes in the effective π-conjugation between the aryl group and the rest of the π-conjugated system. The rotation and isomerization of aryl groups in π-conjugated systems significantly impact their electronic and optical properties. These changes can modify the efficiency of π-conjugation, affecting charge transfer processes, absorption properties, light emission, and electrical conductivity. In designing optoelectronic materials, such as organic dyes, organic semiconductors, or electrochromic materials, controlling the rotation and isomerization of aryl groups can be crucial for optimizing their functionality. Full article
Show Figures

Graphical abstract

12 pages, 823 KiB  
Article
Dynamics of Supramolecular Ionic Gels by Means of Nuclear Magnetic Resonance Relaxometry—The Case of [BMIM][Cl]/Propylene Carbonate Gel
by Michał Bielejewski, Robert Kruk and Danuta Kruk
Molecules 2025, 30(12), 2598; https://doi.org/10.3390/molecules30122598 - 15 Jun 2025
Viewed by 414
Abstract
Aiming to obtain insight into the dynamic properties of ionogels, 1H NMR relaxation experiments were performed for an ionogel composed of 1-butyl-3-methyl-imidazolium chloride [BMIM][Cl] and propylene carbonate. The experiments were conducted in the frequency range of 10 kHz to 20 MHz, spanning [...] Read more.
Aiming to obtain insight into the dynamic properties of ionogels, 1H NMR relaxation experiments were performed for an ionogel composed of 1-butyl-3-methyl-imidazolium chloride [BMIM][Cl] and propylene carbonate. The experiments were conducted in the frequency range of 10 kHz to 20 MHz, spanning the temperature range of 273 K to 338 K. The data were analyzed in term s of a relaxation model including two relaxation contributions—one of them associated with anisotropic (two-dimensional) translation diffusion, the second one representing a power law dependence of spin-lattice relaxation rates on the resonance frequency. The power law relaxation term (characterized by a very low power law factor of about 0.1) was attributed to the collective dynamics of the partially immobilized propylene carbonate matrix, while the relaxation contribution associated with anisotropic translation diffusion was attributed to the movement of BMIM cations in the matrix; the translation diffusion coefficient was estimated as varying in the range of 10−13 m2/s–10−12 m2/s. Moreover, other parameters were determined as a result of the analysis, such as the residence lifetime on the matrix surfaces. Subsequently, the temperature dependencies of the determined parameters were assessed. Full article
(This article belongs to the Special Issue Advanced Magnetic Resonance Methods in Materials Chemistry Analysis)
Show Figures

Figure 1

Back to TopTop