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Molecules, Volume 29, Issue 5 (March-1 2024) – 268 articles

Cover Story (view full-size image): NK cells are highly valued in immunotherapy for their ability to rapidly kill tumor cells as well as their favorable safety profile. Their cytotoxic function is governed by a complex interplay of activating and inhibiting receptors, presenting a plethora of antigens for functional modulation via antibodies. Effective NK cell activation is attainable through the stimulation of activating receptors such as CD16, or by blocking inhibitory checkpoint molecules like TIGIT. Coupled with a binding domain for tumor-associated proteins such as B7-H3, these components can orchestrate the formation of an immunological synapse. The novel trispecific 2+1 common light chain NK cell engager B7-H3xCD16xTIGIT combines these three functionalities, facilitating potent apoptosis induction of cancer cells. View this paper
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23 pages, 10733 KiB  
Review
Progress in Lewis-Acid-Templated Diels–Alder Reactions
by Jun Ishihara
Molecules 2024, 29(5), 1187; https://doi.org/10.3390/molecules29051187 - 06 Mar 2024
Viewed by 778
Abstract
The synthesis of natural products with complicated architectures often requires the use of segments with functional groups that can be structurally transformed with the desired stereogenic centers. Bicyclic 𝛾-lactones have great potential as a suitable segment for natural product synthesis. However, the stereoselective [...] Read more.
The synthesis of natural products with complicated architectures often requires the use of segments with functional groups that can be structurally transformed with the desired stereogenic centers. Bicyclic 𝛾-lactones have great potential as a suitable segment for natural product synthesis. However, the stereoselective construction of such functionalized bicyclic 𝛾-lactones is not as straightforward as one might expect. The template-mediated Diels–Alder reaction is one of the most powerful and versatile methods for providing bicyclic 𝛾-lactones with high regioselectivity and stereoselectivity. In this reaction, the diene is linked to the dienophile by a temporary tether, allowing the reaction to proceed efficiently, yielding a product that can be used for natural product synthesis. This review describes some important instances of the template-mediated Diels–Alder reaction and its application to the synthesis of biologically active compounds. Full article
(This article belongs to the Special Issue Biological Activity of Natural and Synthetic Compounds 2.0)
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17 pages, 3052 KiB  
Article
Synthesis, Crystal Structures, Genotoxicity, and Antifungal and Antibacterial Studies of Ni(II) and Cd(II) Pyrazole Amide Coordination Complexes
by Amal El Mahdaoui, Smaail Radi, Youssef Draoui, Mohamed El Massaoudi, Sabir Ouahhoud, Abdeslam Asehraou, Nour Eddine Bentouhami, Ennouamane Saalaoui, Redouane Benabbes, Koen Robeyns and Yann Garcia
Molecules 2024, 29(5), 1186; https://doi.org/10.3390/molecules29051186 - 06 Mar 2024
Viewed by 623
Abstract
In this study, we synthesized two coordination complexes based on pyrazole-based ligands, namely 1,5-dimethyl-N-phenyl-1H-pyrazole-3-carboxamide (L1) and 1,5-dimethyl-N-propyl-1H-pyrazole-3-carboxamide (L2), with the aim to investigate bio-inorganic properties. Their crystal structures revealed a mononuclear complex [Ni( [...] Read more.
In this study, we synthesized two coordination complexes based on pyrazole-based ligands, namely 1,5-dimethyl-N-phenyl-1H-pyrazole-3-carboxamide (L1) and 1,5-dimethyl-N-propyl-1H-pyrazole-3-carboxamide (L2), with the aim to investigate bio-inorganic properties. Their crystal structures revealed a mononuclear complex [Ni(L1)2](ClO4)2 (C1) and a dinuclear complex [Cd2(L2)2]Cl4 (C2). Very competitive antifungal and anti-Fusarium activities were found compared to the reference standard cycloheximide. Additionally, L1 and L2 present very weak genotoxicity in contrast to the observed increase in genotoxicity for the coordination complexes C1 and C2. Full article
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38 pages, 7816 KiB  
Review
Current Trends in Sirtuin Activator and Inhibitor Development
by Karina L. Bursch, Christopher J. Goetz and Brian C. Smith
Molecules 2024, 29(5), 1185; https://doi.org/10.3390/molecules29051185 - 06 Mar 2024
Viewed by 882
Abstract
Sirtuins are NAD+-dependent protein deacylases and key metabolic regulators, coupling the cellular energy state with selective lysine deacylation to regulate many downstream cellular processes. Humans encode seven sirtuin isoforms (Sirt1-7) with diverse subcellular localization and deacylase targets. Sirtuins are considered protective [...] Read more.
Sirtuins are NAD+-dependent protein deacylases and key metabolic regulators, coupling the cellular energy state with selective lysine deacylation to regulate many downstream cellular processes. Humans encode seven sirtuin isoforms (Sirt1-7) with diverse subcellular localization and deacylase targets. Sirtuins are considered protective anti-aging proteins since increased sirtuin activity is canonically associated with lifespan extension and decreased activity with developing aging-related diseases. However, sirtuins can also assume detrimental cellular roles where increased activity contributes to pathophysiology. Modulation of sirtuin activity by activators and inhibitors thus holds substantial potential for defining the cellular roles of sirtuins in health and disease and developing therapeutics. Instead of being comprehensive, this review discusses the well-characterized sirtuin activators and inhibitors available to date, particularly those with demonstrated selectivity, potency, and cellular activity. This review also provides recommendations regarding the best-in-class sirtuin activators and inhibitors for practical research as sirtuin modulator discovery and refinement evolve. Full article
(This article belongs to the Section Chemical Biology)
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14 pages, 5452 KiB  
Article
Experimental and Simulation Studies of Imidazolium Chloride Ionic Liquids with Different Alkyl Chain Lengths for Viscosity Reductions in Heavy Crude Oil: The Effect on Asphaltene Dispersion
by Chaoyue Xiang, Yangwen Zhu, Guanghao Liu, Tao Liu, Xinru Xu and Jingyi Yang
Molecules 2024, 29(5), 1184; https://doi.org/10.3390/molecules29051184 - 06 Mar 2024
Viewed by 391
Abstract
Heavy crude oil poses challenges in terms of extraction and transportation due to its high viscosity. In the pursuit of effective methods to reduce viscosity in heavy crude oil, this study investigates the potential of imidazolium chloride ionic liquids with varying alkyl chain [...] Read more.
Heavy crude oil poses challenges in terms of extraction and transportation due to its high viscosity. In the pursuit of effective methods to reduce viscosity in heavy crude oil, this study investigates the potential of imidazolium chloride ionic liquids with varying alkyl chain lengths as viscosity reducers. The experimental results demonstrate that the addition of 1-dodecyl-3-methylimidazole chloride ([C12-MIM]Cl) leads to a maximum viscosity reduction of 49.87%. Solubility parameters were calculated based on characterization of the average molecular structure of the asphaltenes. The viscosity reduction effect is enhanced when the solubility parameter of the ionic liquid closely matches that of the asphaltene. The initial asphaltene deposition point of heavy crude oil is increased from 63% to 68% with the addition of 150 mg/L [C12-MIM]Cl. Furthermore, the average particle size of asphaltene deposits decreases from 79.35 μm to 48.54 μm. The viscosity of heavy crude oil is influenced by the aggregation of asphaltenes. The ability of ionic liquids, especially those with longer alkyl chains, to disperse asphaltene molecules and reduce viscosity has been confirmed through molecular dynamics and quantum mechanical simulations. Full article
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19 pages, 1003 KiB  
Review
Therapeutic Potential of Fungal Terpenes and Terpenoids: Application in Skin Diseases
by Monika Trepa, Katarzyna Sułkowska-Ziaja, Katarzyna Kała and Bożena Muszyńska
Molecules 2024, 29(5), 1183; https://doi.org/10.3390/molecules29051183 - 06 Mar 2024
Viewed by 777
Abstract
Terpenes and their derivatives comprise a diverse group of natural compounds with versatile medicinal properties. This article elucidates the general characteristics of fungal terpenes and terpenoids, encompassing their structure and biogenesis. The focal point of this work involves a comprehensive overview of these [...] Read more.
Terpenes and their derivatives comprise a diverse group of natural compounds with versatile medicinal properties. This article elucidates the general characteristics of fungal terpenes and terpenoids, encompassing their structure and biogenesis. The focal point of this work involves a comprehensive overview of these compounds, highlighting their therapeutic properties, mechanisms of action, and potential applications in treating specific skin conditions. Numerous isolated terpenes and terpenoids have demonstrated noteworthy anti-inflammatory and anti-microbial effects, rivalling or surpassing the efficacy of currently employed treatments for inflammation or skin infections. Due to their well-documented antioxidant and anti-cancer attributes, these compounds exhibit promise in both preventing and treating skin cancer. Terpenes and terpenoids sourced from fungi display the capability to inhibit tyrosinase, suggesting potential applications in addressing skin pigmentation disorders and cancers linked to melanogenesis dysfunctions. This paper further disseminates the findings of clinical and in vivo research on fungal terpenes and terpenoids conducted thus far. Full article
(This article belongs to the Special Issue Terpenes, Steroids and Their Derivatives II)
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14 pages, 3461 KiB  
Article
Electrocatalytic Degradation of Phenolic Wastewater Using a Zero-Gap Flow-Through Reactor Coupled with a 3D Ti/RuO2-TiO2@Pt Electrode
by Yunqing Zhu, Kaiyue Wen, Bingqing Li, Yirong Hao and Jianjun Zhou
Molecules 2024, 29(5), 1182; https://doi.org/10.3390/molecules29051182 - 06 Mar 2024
Viewed by 418
Abstract
In this study, the performance of a zero-gap flow-through reactor with three-dimensional (3D) porous Ti/RuO2-TiO2@Pt anodes was systematically investigated for the electrocatalytic oxidation of phenolic wastewater, considering phenol and 4-nitrophenol (4-NP) as the target pollutants. The optimum parameters for [...] Read more.
In this study, the performance of a zero-gap flow-through reactor with three-dimensional (3D) porous Ti/RuO2-TiO2@Pt anodes was systematically investigated for the electrocatalytic oxidation of phenolic wastewater, considering phenol and 4-nitrophenol (4-NP) as the target pollutants. The optimum parameters for the electrochemical oxidation of phenol and 4-NP were examined. For phenol degradation, at an initial concentration of 50 mg/L, initial pH of 7, NaCl concentration of 10.0 g/L, current density of 10 mA/cm2, and retention time of 30 min, the degradation efficiency achieved was 95.05%, with an energy consumption of 15.39 kWh/kg; meanwhile, for 4-NP, the degradation efficiency was 98.42% and energy consumption was 19.21 kWh/kg (at an initial concentration of 40 mg/L, initial pH of 3, NaCl concentration of 10.0 g/L, current density of 10 mA/cm2, and retention time of 30 min). The electrocatalytic oxidation of phenol and 4-NP conformed to the pseudo-first-order kinetics model, and the k values were 0.2562 min−1 and 0.1736 min−1, respectively, which are 1.7 and 3.6-times higher than those of a conventional electrolyzer. Liquid chromatography–mass spectrometry (LC–MS) was used to verify the intermediates formed during the degradation of phenol or 4-NP and a possible degradation pathway was provided. The extremely narrow electrode distance and the flow-through configuration of the zero-gap flow-through reactor were thought to be essential for its lower energy consumption and higher mass transfer efficiency. The zero-gap flow-through reactor with a novel 3D porous Ti/RuO2-TiO2@Pt electrode is a superior alternative for the treatment of industrial wastewater. Full article
(This article belongs to the Section Electrochemistry)
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14 pages, 4352 KiB  
Article
Engineering Enhanced Antimicrobial Properties in α-Conotoxin RgIA through D-Type Amino Acid Substitution and Incorporation of Lysine and Leucine Residues
by Minghe Wang, Zhouyuji Liao, Dongting Zhangsun, Yong Wu and Sulan Luo
Molecules 2024, 29(5), 1181; https://doi.org/10.3390/molecules29051181 - 06 Mar 2024
Viewed by 522
Abstract
Antimicrobial peptides (AMPs), acknowledged as host defense peptides, constitute a category of predominant cationic peptides prevalent in diverse life forms. This study explored the antibacterial activity of α-conotoxin RgIA, and to enhance its stability and efficacy, D-amino acid substitution was employed, resulting in [...] Read more.
Antimicrobial peptides (AMPs), acknowledged as host defense peptides, constitute a category of predominant cationic peptides prevalent in diverse life forms. This study explored the antibacterial activity of α-conotoxin RgIA, and to enhance its stability and efficacy, D-amino acid substitution was employed, resulting in the synthesis of nine RgIA mutant analogs. Results revealed that several modified RgIA mutants displayed inhibitory efficacy against various pathogenic bacteria and fungi, including Candida tropicalis and Escherichia coli. Mechanistic investigations elucidated that these polypeptides achieved antibacterial effects through the disruption of bacterial cell membranes. The study further assessed the designed peptides’ hemolytic activity, cytotoxicity, and safety. Mutants with antibacterial activity exhibited lower hemolytic activity and cytotoxicity, with Pep 8 demonstrating favorable safety in mice. RgIA mutants incorporating D-amino acids exhibited notable stability and adaptability, sustaining antibacterial properties across diverse environmental conditions. This research underscores the potential of the peptide to advance innovative oral antibiotics, offering a novel approach to address bacterial infections. Full article
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12 pages, 2569 KiB  
Article
Inhibitory Effects of the Polyphenols from the Root of Rhizophora apiculata Blume on Fatty Acid Synthase Activity and Human Colon Cancer Cells
by Yan Liang, Yue Ban, Lei Liu and Yanchun Li
Molecules 2024, 29(5), 1180; https://doi.org/10.3390/molecules29051180 - 06 Mar 2024
Viewed by 451
Abstract
Marine mangrove vegetation has been traditionally employed in folk medicine to address various ailments. Notably, Rhizophora apiculata Blume has exhibited noteworthy properties, demonstrating efficacy against cancer, viruses, and bacteria. The enzyme fatty acid synthase (FAS) plays a pivotal role in de novo fatty [...] Read more.
Marine mangrove vegetation has been traditionally employed in folk medicine to address various ailments. Notably, Rhizophora apiculata Blume has exhibited noteworthy properties, demonstrating efficacy against cancer, viruses, and bacteria. The enzyme fatty acid synthase (FAS) plays a pivotal role in de novo fatty acid synthesis, making it a promising target for combating colon cancer. Our study focused on evaluating the FAS inhibitory effects of both the crude extract and three isolated compounds from R. apiculata. The n-butanol fraction of R. apiculata extract (BFR) demonstrated a significant inhibition of FAS, with an IC50 value of 93.0 µg/mL. For inhibition via lyoniresinol-3α-O-β-rhamnopyranoside (LR), the corresponding IC50 value was 20.1 µg/mL (35.5 µM). LR competitively inhibited the FAS reaction with acetyl-CoA, noncompetitively with malonyl-CoA, and in a mixed manner with NADPH. Our results also suggest that both BFR and LR reversibly bind to the KR domain of FAS, hindering the reduction of saturated acyl groups in fatty acid synthesis. Furthermore, BFR and LR displayed time-dependent inhibition for FAS, with kobs values of 0.0045 min−1 and 0.026 min−1, respectively. LR also exhibited time-dependent inhibition on the KR domain, with a kobs value of 0.019 min−1. In human colon cancer cells, LR demonstrated the ability to reduce viability and inhibit intracellular FAS activity. Notably, the effects of LR on human colon cancer cells could be reversed with the end product of FAS-catalyzed chemical reactions, affirming the specificity of LR on FAS. These findings underscore the potential of BFR and LR as potent FAS inhibitors, presenting novel avenues for the treatment of human colon cancer. Full article
(This article belongs to the Special Issue Fruits and Vegetables as Prospective Reserves of Bioactive Compounds)
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16 pages, 7959 KiB  
Article
Synthesis and Biological Evaluation of New Dihydrofuro[3,2-b]piperidine Derivatives as Potent α-Glucosidase Inhibitors
by Haibo Wang, Xiaojiang Huang, Yang Pan, Guoqing Zhang, Senling Tang, Huawu Shao and Wei Jiao
Molecules 2024, 29(5), 1179; https://doi.org/10.3390/molecules29051179 - 06 Mar 2024
Viewed by 436
Abstract
Inhibition of glycoside hydrolases has widespread application in the treatment of diabetes. Based on our previous findings, a series of dihydrofuro[3,2-b]piperidine derivatives was designed and synthesized from D- and L-arabinose. Compounds 32 (IC50 = 0.07 μM) and 28 (IC50 [...] Read more.
Inhibition of glycoside hydrolases has widespread application in the treatment of diabetes. Based on our previous findings, a series of dihydrofuro[3,2-b]piperidine derivatives was designed and synthesized from D- and L-arabinose. Compounds 32 (IC50 = 0.07 μM) and 28 (IC50 = 0.5 μM) showed significantly stronger inhibitory potency against α-glucosidase than positive control acarbose. The study of the structure–activity relationship of these compounds provides a new clue for the development of new α-glucosidase inhibitors. Full article
(This article belongs to the Collection Advances in Glycosciences)
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21 pages, 10860 KiB  
Article
Discovery of Potential Anti-Microbial Molecules and Spectrum Correlation Effect of Ardisia crenata Sims via High-Performance Liquid Chromatography Fingerprints and Molecular Docking
by Chunli Zhao, Changbin Wang, Yongqiang Zhou, Tao Hu, Yan Zhang, Xiang Lv, Jiaxin Li and Ying Zhou
Molecules 2024, 29(5), 1178; https://doi.org/10.3390/molecules29051178 - 06 Mar 2024
Viewed by 551
Abstract
Ardisia crenata Sims, an important ethnic medicine, is recorded in the Chinese Pharmacopoeia for treating laryngeal diseases and upper respiratory tract infections. This study aimed to evaluate the antimicrobial effect of extracts and potential antimicrobial compounds of A. crenata Sims. It was found [...] Read more.
Ardisia crenata Sims, an important ethnic medicine, is recorded in the Chinese Pharmacopoeia for treating laryngeal diseases and upper respiratory tract infections. This study aimed to evaluate the antimicrobial effect of extracts and potential antimicrobial compounds of A. crenata Sims. It was found that the roots of A. crenata Sims have a potential inhibitory effect on Candida albicans and Aspergillus flavus, with MICs of 1.56 mg/mL and 0.39 mg/mL, and the leaves of A. crenata Sims have a potential inhibitory effect on Pseudomonas aeruginosa and Staphylococcus aureus, with MICs of 3.12 mg/mL and 6.77 mg/mL, respectively. Meanwhile, five compounds including one catechin and four bergenins were obtained from roots. These components were identified on the fingerprint spectrum, representing chromatographic peaks 16, 21, 22, 23, and 25, respectively. Among these, 11-β-d-glucopyranosyl-bergenin and (−)-gallocatechin showed potential inhibition for Staphylococcus aureus and Pseudomonas aeruginosa with MIC of 0.26 and 0.33 mg/mL, respectively. The roots, stems, and leaves of A. crenata Sims are very similar in chemical composition, with large differences in content. Principal component analysis (PCA) and Hierarchical cluster analysis (HCA) showed that 16 batches of A. crenata Sims could be divided into four main production areas: Guizhou, Jiangsu, Guangxi, and Jiangxi. Furthermore, molecular docking results showed that 11-β-d-glucopyranosyl-bergenin had a better affinity for Casein lytic proteinase P (ClpP), and (−)-gallocatechin possessed a strong affinity for LasA hydrolysis protease and LasB elastase. These findings suggest catechin and bergenins from A. crenata Sims can be used as antimicrobial activity molecules. Full article
(This article belongs to the Special Issue Antimicrobial Activity of Natural Extracts)
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15 pages, 20674 KiB  
Article
Biodegradable Metal Complex-Gated Organosilica for Dually Enhanced Chemodynamic Therapy through GSH Depletions and NIR Light-Triggered Photothermal Effects
by Lin Kong, Jian Li, Yunxiu Zhang, Jian Wang, Ke Liang, Xiaokuang Xue, Tiejin Chen, Yongliang Hao, Haohui Ren, Pengfei Wang and Jiechao Ge
Molecules 2024, 29(5), 1177; https://doi.org/10.3390/molecules29051177 - 06 Mar 2024
Viewed by 434
Abstract
Hollow silica spheres have been widely studied for drug delivery because of their excellent biosecurity and high porosity. However, difficulties with degradation in the tumor microenvironment (TME) and premature leaking during drug delivery limit their clinical applications. To alleviate these problems, herein, hollow [...] Read more.
Hollow silica spheres have been widely studied for drug delivery because of their excellent biosecurity and high porosity. However, difficulties with degradation in the tumor microenvironment (TME) and premature leaking during drug delivery limit their clinical applications. To alleviate these problems, herein, hollow organosilica spheres (HOS) were initially prepared using a “selective etching strategy” and loaded with a photothermal drug: new indocyanine green (IR820). Then, the Cu2+–tannic acid complex (Cu-TA) was deposited on the surface of the HOS, and a new nanoplatform named HOS@IR820@Cu-TA (HICT) was finally obtained. The deposition of Cu-TA can gate the pores of HOS completely to prevent the leakage of IR820 and significantly enhance the loading capacity of HOS. Once in the mildly acidic TME, the HOS and outer Cu-TA decompose quickly in response, resulting in the release of Cu2+ and IR820. The released Cu2+ can react with the endogenous glutathione (GSH) to consume it and produce Cu+, leading to the enhanced production of highly toxic ·OH through a Fenton-like reaction due to the overexpressed H2O2 in the TME. Meanwhile, the ·OH generation was remarkably enhanced by the NIR light-responsive photothermal effect of IR820. These collective properties of HICT enable it to be a smart nanomedicine for dually enhanced chemodynamic therapy through GSH depletions and NIR light-triggered photothermal effects. Full article
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18 pages, 3858 KiB  
Article
Flame Retardancy of Short Flax Fibers Modified by Radiation-Induced Grafting of Phosphonated Monomers: Comparison between Pre- and Simultaneous Irradiation Grafting
by Clément Brendlé, Roland El Hage, Jean-Louis Clément, Sophie Rouif, Rodolphe Sonnier and Belkacem Otazaghine
Molecules 2024, 29(5), 1176; https://doi.org/10.3390/molecules29051176 - 06 Mar 2024
Viewed by 541
Abstract
Short flax fibers have been modified by radiation-induced grafting using methacrylate monomers containing phosphorus to give them a flame-retardant character. Two methodologies, namely pre-irradiation and simultaneous irradiation grafting, were examined. Certain parameters, notably the dose and the irradiation source (e-Beam and γ rays), [...] Read more.
Short flax fibers have been modified by radiation-induced grafting using methacrylate monomers containing phosphorus to give them a flame-retardant character. Two methodologies, namely pre-irradiation and simultaneous irradiation grafting, were examined. Certain parameters, notably the dose and the irradiation source (e-Beam and γ rays), were evaluated. The grafting efficiency, in terms of phosphorus content (mass percentage), was measured by X-ray fluorescence spectrometry (XRF). Using simultaneous irradiation, 2.39 wt% phosphorus could be obtained from 10 kGy, compared to 100 kGy in pre-irradiation. Furthermore, for similar phosphorus levels, the location of the grafted polymer chains was different for the two methodologies. The effect of phosphorus content on thermal properties and fire behavior was evaluated on a microscopic scale using a pyrolytic flow combustion calorimeter (PCFC) and on a laboratory scale using a cone calorimeter. It was then pointed out that flammability was linked to the phosphorus content and likely its location, which is associated with the radiation-induced grafting methodology, showing that the grafting conditions influence the final fire properties. Simultaneous irradiation, thus, proved to be more interesting in terms of efficiency and final properties. Full article
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13 pages, 3573 KiB  
Article
Investigation of Flame Structures of Double-Base Propellant and Modified Double-Base Propellant Containing Nitramine Using OH-PLIF and Kinetic Simulation
by Yiping Wang, Yan Zhang, Heng Li, Ergang Yao, Jin Yu, Fengqi Zhao and Siyu Xu
Molecules 2024, 29(5), 1175; https://doi.org/10.3390/molecules29051175 - 06 Mar 2024
Viewed by 426
Abstract
The combustion behavior of various propellant samples, including double-base propellants, pressed nitramine powders, and modified double-base propellants containing nitramine, was examined using OH-PLIF technology. The combustion process took place within a combustion chamber, and images capturing the flame at the moment of stable [...] Read more.
The combustion behavior of various propellant samples, including double-base propellants, pressed nitramine powders, and modified double-base propellants containing nitramine, was examined using OH-PLIF technology. The combustion process took place within a combustion chamber, and images capturing the flame at the moment of stable combustion were selected for further analysis. The distribution and production rate of OH radicals in both the double-base propellant and the nitramine-modified double-base propellant were simulated using Chemkin-17.0 software. The outcomes from both the experimental and simulation studies revealed that the concentration of OH radicals increased with a higher content of NG in the double-base propellant. In the modified double-base propellant containing RDX, the OH radical concentration decreased as the RDX content increased, with these tendencies of change aligning closely with the simulation results. Full article
(This article belongs to the Special Issue Combustion Reaction: Experimental and Theoretical Analysis)
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28 pages, 17235 KiB  
Article
Combination of Hydrogen and Halogen Bonds in the Crystal Structures of 5-Halogeno-1H-isatin-3-oximes: Involvement of the Oxime Functionality in Halogen Bonding
by Eric Meier, Wilhelm Seichter and Monika Mazik
Molecules 2024, 29(5), 1174; https://doi.org/10.3390/molecules29051174 - 06 Mar 2024
Viewed by 418
Abstract
Various functional groups have been considered as acceptors for halogen bonds, but the oxime functionality has received very little attention in this context. In this study, we focus on the analysis of the hydrogen and halogen bond preferences observed in the crystal structures [...] Read more.
Various functional groups have been considered as acceptors for halogen bonds, but the oxime functionality has received very little attention in this context. In this study, we focus on the analysis of the hydrogen and halogen bond preferences observed in the crystal structures of 5-halogeno-1H-isatin-3-oximes. These molecules can be involved in various non-covalent interactions, and the competition between these interactions has a decisive influence on their self-organization. In particular, we were interested to see whether the crystal structures of 5-halogeno-1H-isatin-3-oximes, especially bromine- and iodine-substituted ones, are characterized by the presence of halogen bonds formed with the oxime functionality. The oxime group proved its ability to compete with the other strong donor and acceptor sites by participating in the formation of cyclic hydrogen-bonded heterosynthons oxime∙∙∙amide and Ooxime∙∙∙Br/I halogen bonds. Full article
(This article belongs to the Special Issue Exploring Non-bonded Interactions in Macromolecular Chemistry)
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16 pages, 4844 KiB  
Article
Effect of Copper Antifouling Paint on Marine Degradation of Polypropylene: Uneven Distribution of Microdebris between Nagasaki Port and Goto Island, Japan
by Hisayuki Nakatani, Kaito Yamashiro, Taishi Uchiyama, Suguru Motokucho, Anh Thi Ngoc Dao, Hee-Jin Kim, Mitsuharu Yagi and Yusaku Kyozuka
Molecules 2024, 29(5), 1173; https://doi.org/10.3390/molecules29051173 - 06 Mar 2024
Viewed by 494
Abstract
Microplastics (MP) encompass not only plastic products but also paint particles. Marine microdebris, including MP, was retrieved from five sampling stations spanning Nagasaki-Goto island and was classified into six types, primarily consisting of MP (A), Si-based (B), and Cu-based (C) paint particles. Type-A [...] Read more.
Microplastics (MP) encompass not only plastic products but also paint particles. Marine microdebris, including MP, was retrieved from five sampling stations spanning Nagasaki-Goto island and was classified into six types, primarily consisting of MP (A), Si-based (B), and Cu-based (C) paint particles. Type-A particles, i.e., MP, were exceedingly small, with 74% of them having a long diameter of 25 µm or less. The vertical distribution of type C, containing cuprous oxide, exhibited no depth dependence, with its dominant size being less than 7 μm. It was considered that the presence of type C was associated with a natural phenomenon of MP loss. To clarify this, polypropylene (PP) samples containing cuprous oxide were prepared, and their accelerated degradation behavior was studied using a novel enhanced degradation method employing a sulfate ion radical as an initiator. Infrared spectroscopy revealed the formation of a copper soap compound in seawater. Scanning electron microscopy/energy-dispersive X-ray spectroscopy analysis indicated that the chemical reactions between Cl and cuprous oxide produced Cu+ ions. The acceleration of degradation induced by the copper soap formed was studied through the changes in the number of PP chain scissions, revealing that the presence of type-C accelerated MP degradation. Full article
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19 pages, 3069 KiB  
Review
Recent Advances in Antibacterial Coatings to Combat Orthopedic Implant-Associated Infections
by Seref Akay and Anan Yaghmur
Molecules 2024, 29(5), 1172; https://doi.org/10.3390/molecules29051172 - 06 Mar 2024
Viewed by 664
Abstract
Implant-associated infections (IAIs) represent a major health burden due to the complex structural features of biofilms and their inherent tolerance to antimicrobial agents and the immune system. Thus, the viable options to eradicate biofilms embedded on medical implants are surgical operations and long-term [...] Read more.
Implant-associated infections (IAIs) represent a major health burden due to the complex structural features of biofilms and their inherent tolerance to antimicrobial agents and the immune system. Thus, the viable options to eradicate biofilms embedded on medical implants are surgical operations and long-term and repeated antibiotic courses. Recent years have witnessed a growing interest in the development of robust and reliable strategies for prevention and treatment of IAIs. In particular, it seems promising to develop materials with anti-biofouling and antibacterial properties for combating IAIs on implants. In this contribution, we exclusively focus on recent advances in the development of modified and functionalized implant surfaces for inhibiting bacterial attachment and eventually biofilm formation on orthopedic implants. Further, we highlight recent progress in the development of antibacterial coatings (including self-assembled nanocoatings) for preventing biofilm formation on orthopedic implants. Among the recently introduced approaches for development of efficient and durable antibacterial coatings, we focus on the use of safe and biocompatible materials with excellent antibacterial activities for local delivery of combinatorial antimicrobial agents for preventing and treating IAIs and overcoming antimicrobial resistance. Full article
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14 pages, 685 KiB  
Article
Simultaneous Quantification of Nine Target Compounds in Traditional Korean Medicine, Bopyeo-Tang, Using High-Performance Liquid Chromatography–Photodiode Array Detector and Ultra-Performance Liquid Chromatography–Tandem Mass Spectrometry
by Chang-Seob Seo
Molecules 2024, 29(5), 1171; https://doi.org/10.3390/molecules29051171 - 06 Mar 2024
Viewed by 454
Abstract
Bopyeo-tang (BPT) is composed of six medicinal herbs (Morus alba L., Rehmannia glutinosa (Gaertn.) DC., Panax ginseng C.A.Mey., Aster tataricus L.f., Astragalus propinquus Schischkin, and Schisandra chinensis (Turcz.) Baill.) and has been used for the treatment of lung diseases. This study focused [...] Read more.
Bopyeo-tang (BPT) is composed of six medicinal herbs (Morus alba L., Rehmannia glutinosa (Gaertn.) DC., Panax ginseng C.A.Mey., Aster tataricus L.f., Astragalus propinquus Schischkin, and Schisandra chinensis (Turcz.) Baill.) and has been used for the treatment of lung diseases. This study focused on establishing an analytical method that can simultaneously quantify nine target compounds (i.e., hydroxymethylfurfural, mulberroside A, chlorogenic acid, calycosin-7-O-glucoside, 3,5-dicaffeoylquinic acid, quercetin, kaempferol, schizandrin, and gomisin A) from a BPT sample using high-performance liquid chromatography with a photodiode array detector (HPLC–PDA) and ultra-performance liquid chromatography with tandem mass spectrometry (UPLC–MS/MS). The separation of compounds in both analyses was performed on a C18 reversed-phase column using the gradient elution of water–acetonitrile as the mobile phase. In particular, the multiple reaction monitoring mode was applied for quick and accurate detection in UPLC–MS/MS analysis. As a result of analyzing the two methods, HPLC–PDA and UPLC–MS/MS, the coefficient of determination of the regression equation for each compound was ≥0.9952, and recovery was 85.99−106.40% (relative standard deviation (RSD) < 9.58%). Precision testing of the nine compounds was verified (RSD < 10.0%). The application of these analytical assays under optimized conditions for quantitative analysis of the BPT sample gave 0.01–4.70 mg/g. Therefore, these two assays could be used successfully to gather basic data for clinical research and the quality control of BPT. Full article
(This article belongs to the Special Issue Chromatographic Screening of Natural Products)
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12 pages, 2360 KiB  
Review
Research Progress of Ozone/Peroxymonosulfate Advanced Oxidation Technology for Degrading Antibiotics in Drinking Water and Wastewater Effluent: A Review
by Hai Lu, Xinglin Chen, Qiao Cong, Qingpo Li, Xiaoyan Wang, Shuang Zhong, Huan Deng and Bojiao Yan
Molecules 2024, 29(5), 1170; https://doi.org/10.3390/molecules29051170 - 06 Mar 2024
Viewed by 569
Abstract
Nowadays, antibiotics are widely used, increasing the risk of contamination of the water body and further threatening human health. The traditional water treatment process is less efficient in degrading antibiotics, and the advanced oxidation process (AOPs) is cleaner and more efficient than the [...] Read more.
Nowadays, antibiotics are widely used, increasing the risk of contamination of the water body and further threatening human health. The traditional water treatment process is less efficient in degrading antibiotics, and the advanced oxidation process (AOPs) is cleaner and more efficient than the traditional biochemical degradation process. The combined ozone/peroxymonosulfate (PMS) advanced oxidation process (O3/PMS) based on sulfate radical (SO4•−) and hydroxyl radical (•OH) has developed rapidly in recent years. The O3/PMS process has become one of the most effective ways to treat antibiotic wastewater. The reaction mechanism of O3/PMS was reviewed in this paper, and the research and application progress of the O3/PMS process in the degradation of antibiotics in drinking water and wastewater effluent were evaluated. The operation characteristics and current application range of the process were summarized, which has a certain reference value for further research on O3/PMS process. Full article
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15 pages, 5113 KiB  
Article
Construction of Bi2WO6/g-C3N4 Z-Scheme Heterojunction and Its Enhanced Photocatalytic Degradation of Tetracycline with Persulfate under Solar Light
by Yukun Li, Haiyang Zhang, Dan Zhang, Sen Yao, Shuying Dong, Qishi Chen, Fengjuan Fan, Hongyuan Jia and Mingjia Dong
Molecules 2024, 29(5), 1169; https://doi.org/10.3390/molecules29051169 - 06 Mar 2024
Viewed by 556
Abstract
Z-scheme heterojunction Bi2WO6/g-C3N4 was obtained by a novel hydrothermal process; its photocatalysis–persulfate (PDS) activation for tetracycline (TC) removal was explored under solar light (SL). The structure and photoelectrochemistry behavior of fabricated samples were well characterized by [...] Read more.
Z-scheme heterojunction Bi2WO6/g-C3N4 was obtained by a novel hydrothermal process; its photocatalysis–persulfate (PDS) activation for tetracycline (TC) removal was explored under solar light (SL). The structure and photoelectrochemistry behavior of fabricated samples were well characterized by FT-IR, XRD, XPS, SEM-EDS, UV-vis DRS, Mott-Schottky, PL, photocurrent response, EIS and BET. The critical experimental factors in TC decomposition were investigated, including the Bi2WO6 doping ratio, catalyst dosage, TC concentration, PDS dose, pH, co-existing ion and humic acid (HA). The optimum test conditions were as follows: 0.4 g/L Bi2WO6/g-C3N4 (BC-3), 20 mg/L TC, 20 mg/L PDS and pH = 6.49, and the maximum removal efficiency of TC was 98.0% in 60 min. The decomposition rate in BC-3/SL/PDS system (0.0446 min−1) was 3.05 times higher than that of the g-C3N4/SL/PDS system (0.0146 min−1), which might be caused by the high-efficiency electron transfer inside the Z-scheme Bi2WO6/g-C3N4 heterojunction. Furthermore, the photogenerated hole (h+), superoxide (O2), sulfate radical (SO4) and singlet oxygen (1O2) were confirmed as the key oxidation factors in the BC-3/SL/PDS system for TC degradation by a free radical quenching experiment. Particularly, BC-3 possessed a wide application potential in actual antibiotic wastewater treatment for its superior catalytic performance that emerged in the experiment of co-existing components. Full article
(This article belongs to the Section Applied Chemistry)
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17 pages, 6412 KiB  
Review
Recent Advances in Fluorescent Probes for Cancer Biomarker Detection
by Mingce Tian, Riliga Wu, Caihong Xiang, Guangle Niu and Weijiang Guan
Molecules 2024, 29(5), 1168; https://doi.org/10.3390/molecules29051168 - 06 Mar 2024
Viewed by 810
Abstract
Many important biological species have been identified as cancer biomarkers and are gradually becoming reliable targets for early diagnosis and late therapeutic evaluation of cancer. However, accurate quantitative detection of cancer biomarkers remains challenging due to the complexity of biological systems and the [...] Read more.
Many important biological species have been identified as cancer biomarkers and are gradually becoming reliable targets for early diagnosis and late therapeutic evaluation of cancer. However, accurate quantitative detection of cancer biomarkers remains challenging due to the complexity of biological systems and the diversity of cancer development. Fluorescent probes have been extensively utilized for identifying biological substances due to their notable benefits of being non-invasive, quickly responsive, highly sensitive and selective, allowing real-time visualization, and easily modifiable. This review critiques fluorescent probes used for detecting and imaging cancer biomarkers over the last five years. Focuses are made on the design strategies of small-molecule and nano-sized fluorescent probes, the construction methods of fluorescence sensing and imaging platforms, and their further applications in detection of multiple biomarkers, including enzymes, reactive oxygen species, reactive sulfur species, and microenvironments. This review aims to guide the design and development of excellent cancer diagnostic fluorescent probes, and promote the broad application of fluorescence analysis in early cancer diagnosis. Full article
(This article belongs to the Special Issue Fluorescence Detection of Biomolecules)
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13 pages, 2578 KiB  
Article
Impact of Formalin- and Cryofixation on Raman Spectra of Human Tissues and Strategies for Tumor Bank Inclusion
by Giulia Mirizzi, Finn Jelke, Michel Pilot, Karoline Klein, Gilbert Georg Klamminger, Jean-Jacques Gérardy, Marily Theodoropoulou, Laurent Mombaerts, Andreas Husch, Michel Mittelbronn, Frank Hertel and Felix Bruno Kleine Borgmann
Molecules 2024, 29(5), 1167; https://doi.org/10.3390/molecules29051167 - 06 Mar 2024
Cited by 1 | Viewed by 552
Abstract
Reliable training of Raman spectra-based tumor classifiers relies on a substantial sample pool. This study explores the impact of cryofixation (CF) and formalin fixation (FF) on Raman spectra using samples from surgery sites and a tumor bank. A robotic Raman spectrometer scans samples [...] Read more.
Reliable training of Raman spectra-based tumor classifiers relies on a substantial sample pool. This study explores the impact of cryofixation (CF) and formalin fixation (FF) on Raman spectra using samples from surgery sites and a tumor bank. A robotic Raman spectrometer scans samples prior to the neuropathological analysis. CF samples showed no significant spectral deviations, appearance, or disappearance of peaks, but an intensity reduction during freezing and subsequent recovery during the thawing process. In contrast, FF induces sustained spectral alterations depending on molecular composition, albeit with good signal-to-noise ratio preservation. These observations are also reflected in the varying dual-class classifier performance, initially trained on native, unfixed samples: The Matthews correlation coefficient is 81.0% for CF and 58.6% for FF meningioma and dura mater. Training on spectral differences between original FF and pure formalin spectra substantially improves FF samples’ classifier performance (74.2%). CF is suitable for training global multiclass classifiers due to its consistent spectrum shape despite intensity reduction. FF introduces changes in peak relationships while preserving the signal-to-noise ratio, making it more suitable for dual-class classification, such as distinguishing between healthy and malignant tissues. Pure formalin spectrum subtraction represents a possible method for mathematical elimination of the FF influence. These findings enable retrospective analysis of processed samples, enhancing pathological work and expanding machine learning techniques. Full article
(This article belongs to the Special Issue Past Present and Future of Raman Spectroscopy)
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45 pages, 6382 KiB  
Review
Catalysts of Healing: A Symphony of Synthesis and Clinical Artistry in Small-Molecule Agents for Breast Cancer Alleviation
by Jing Hu, Bi-Yue Zhu and Zhen-Xi Niu
Molecules 2024, 29(5), 1166; https://doi.org/10.3390/molecules29051166 - 05 Mar 2024
Viewed by 728
Abstract
Breast cancer, characterized by its molecular intricacy, has witnessed a surge in targeted therapeutics owing to the rise of small-molecule drugs. These entities, derived from cutting-edge synthetic routes, often encompassing multistage reactions and chiral synthesis, target a spectrum of oncogenic pathways. Their mechanisms [...] Read more.
Breast cancer, characterized by its molecular intricacy, has witnessed a surge in targeted therapeutics owing to the rise of small-molecule drugs. These entities, derived from cutting-edge synthetic routes, often encompassing multistage reactions and chiral synthesis, target a spectrum of oncogenic pathways. Their mechanisms of action range from modulating hormone receptor signaling and inhibiting kinase activity, to impeding DNA damage repair mechanisms. Clinical applications of these drugs have resulted in enhanced patient survival rates, reduction in disease recurrence, and improved overall therapeutic indices. Notably, certain molecules have showcased efficacy in drug-resistant breast cancer phenotypes, highlighting their potential in addressing treatment challenges. The evolution and approval of small-molecule drugs have ushered in a new era for breast cancer therapeutics. Their tailored synthetic pathways and defined mechanisms of action have augmented the precision and efficacy of treatment regimens, paving the way for improved patient outcomes in the face of this pervasive malignancy. The present review embarks on a detailed exploration of small-molecule drugs that have secured regulatory approval for breast cancer treatment, emphasizing their clinical applications, synthetic pathways, and distinct mechanisms of action. Full article
(This article belongs to the Special Issue Synthesis and Evaluation of Bioactivity of Enzyme Inhibitors)
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18 pages, 5996 KiB  
Article
A Comprehensive Study of Al2O3 Mechanical Behavior Using Density Functional Theory and Molecular Dynamics
by Mostafa Fathalian, Eligiusz Postek, Masoud Tahani and Tomasz Sadowski
Molecules 2024, 29(5), 1165; https://doi.org/10.3390/molecules29051165 - 05 Mar 2024
Viewed by 520
Abstract
This study comprehensively investigates Al2O3′s mechanical properties, focusing on fracture toughness, surface energy, Young’s modulus, and crack propagation. The density functional theory (DFT) is employed to model the vacancies in Al2O3, providing essential insights into [...] Read more.
This study comprehensively investigates Al2O3′s mechanical properties, focusing on fracture toughness, surface energy, Young’s modulus, and crack propagation. The density functional theory (DFT) is employed to model the vacancies in Al2O3, providing essential insights into this material’s structural stability and defect formation. The DFT simulations reveal a deep understanding of vacancy-related properties and their impact on mechanical behavior. In conjunction with molecular dynamics (MD) simulations, the fracture toughness and crack propagation in Al2O3 are explored, offering valuable information on material strength and durability. The surface energy of Al2O3 is also assessed using DFT, shedding light on its interactions with the surrounding environment. The results of this investigation highlight the significant impact of oxygen vacancies on mechanical characteristics such as ultimate strength and fracture toughness, drawing comparisons with the effects observed in the presence of aluminum vacancies. Additionally, the research underscores the validation of fracture toughness outcomes derived from both DFT and MD simulations, which align well with findings from established experimental studies. Additionally, the research underscores the validation of fracture toughness outcomes derived from DFT and MD simulations, aligning well with findings from established experimental studies. The combination of DFT and MD simulations provides a robust framework for a comprehensive understanding of Al2O3′s mechanical properties, with implications for material science and engineering applications. Full article
(This article belongs to the Special Issue Feature Papers in Computational and Theoretical Chemistry)
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16 pages, 6290 KiB  
Review
Conductive Polymer-Based Interlayers in Restraining the Polysulfide Shuttle of Lithium–Sulfur Batteries
by Xincheng Hu, Xiaoshuang Zhu, Zhongshuai Ran, Shenghao Liu, Yongya Zhang, Hua Wang and Wei Wei
Molecules 2024, 29(5), 1164; https://doi.org/10.3390/molecules29051164 - 05 Mar 2024
Viewed by 526
Abstract
Lithium–sulfur batteries (LSBs) are considered a promising candidate for next-generation energy storage devices due to the advantages of high theoretical specific capacity, abundant resources and being environmentally friendly. However, the severe shuttle effect of polysulfides causes the low utilization of active substances and [...] Read more.
Lithium–sulfur batteries (LSBs) are considered a promising candidate for next-generation energy storage devices due to the advantages of high theoretical specific capacity, abundant resources and being environmentally friendly. However, the severe shuttle effect of polysulfides causes the low utilization of active substances and rapid capacity fading, thus seriously limiting their practical application. The introduction of conductive polymer-based interlayers between cathodes and separators is considered to be an effective method to solve this problem because they can largely confine, anchor and convert the soluble polysulfides. In this review, the recent progress of conductive polymer-based interlayers used in LSBs is summarized, including free-standing conductive polymer-based interlayers, conductive polymer-based interlayer modified separators and conductive polymer-based interlayer modified sulfur electrodes. Furthermore, some suggestions on rational design and preparation of conductive polymer-based interlayers are put forward to highlight the future development of LSBs. Full article
(This article belongs to the Special Issue Modern Materials in Energy Storage and Conversion)
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18 pages, 1714 KiB  
Article
Synthesis of Benzofuro[3,2-b]indol-3-one Derivatives via Dearomative (3 + 2) Cycloaddition of 2-Nitrobenzofurans and para-Quinamines
by Wei-Cheng Yuan, Hai-Ying Zeng, Yan-Ping Zhang, Jian-Qiang Zhao, Yong You, Jun-Qing Yin, Ming-Qiang Zhou and Zhen-Hua Wang
Molecules 2024, 29(5), 1163; https://doi.org/10.3390/molecules29051163 - 05 Mar 2024
Viewed by 503
Abstract
An efficient dearomative (3 + 2) cycloaddition of para-quinamines and 2-nitrobenzofurans has been developed. This reaction proceeds smoothly under mild conditions and affords a series of benzofuro[3,2-b]indol-3-one derivatives in good to excellent yields (up to 98%) with perfect diastereoselectivities (all [...] Read more.
An efficient dearomative (3 + 2) cycloaddition of para-quinamines and 2-nitrobenzofurans has been developed. This reaction proceeds smoothly under mild conditions and affords a series of benzofuro[3,2-b]indol-3-one derivatives in good to excellent yields (up to 98%) with perfect diastereoselectivities (all cases > 20:1 dr). The scale-up synthesis and versatile derivatizations demonstrate the potential synthetic application of the protocol. A plausible reaction mechanism is also proposed to account for the observed reaction process. This work represents the first instance of the N-triggered dearomative (3 + 2) cycloaddition of 2-nitrobenzofurans. Full article
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17 pages, 3654 KiB  
Article
Alkylammonium Halides for Phase Regulation and Luminescence Modulation of Cesium Copper Iodide Nanocrystals for Light-Emitting Diodes
by Wen Meng, Chuying Wang, Guangyong Xu, Guigen Luo and Zhengtao Deng
Molecules 2024, 29(5), 1162; https://doi.org/10.3390/molecules29051162 - 05 Mar 2024
Viewed by 589
Abstract
All-inorganic cesium copper halide nanocrystals have attracted extensive attention due to their cost-effectiveness, low toxicity, and rich luminescence properties. However, controlling the synthesis of these nanocrystals to achieve a precise composition and high luminous efficiency remains a challenge that limits their future application. [...] Read more.
All-inorganic cesium copper halide nanocrystals have attracted extensive attention due to their cost-effectiveness, low toxicity, and rich luminescence properties. However, controlling the synthesis of these nanocrystals to achieve a precise composition and high luminous efficiency remains a challenge that limits their future application. Herein, we report the effect of oleylammonium iodide on the synthesis of copper halide nanocrystals to control the composition and phase and modulate their photoluminescence (PL) quantum yields (QYs). For CsCu2I3, the PL peak is centered at 560 nm with a PLQY of 47.3%, while the PL peak of Cs3Cu2I5 is located at 440 nm with an unprecedently high PLQY of 95.3%. Furthermore, the intermediate-state CsCu2I3/Cs3Cu2I5 heterostructure shows white light emission with a PLQY of 66.4%, chromaticity coordinates of (0.3176, 0.3306), a high color rendering index (CRI) of 90, and a correlated color temperature (CCT) of 6234 K, indicating that it is promising for single-component white-light-emitting applications. The nanocrystals reported in this study have excellent luminescence properties, low toxicity, and superior stability, so they are more suitable for future light-emitting applications. Full article
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12 pages, 2859 KiB  
Article
1,3,6-Trigalloylglucose: A Novel Potent Anti-Helicobacter pylori Adhesion Agent Derived from Aqueous Extracts of Terminalia chebula Retz
by Ling Ou, Zhixiang Zhu, Yajie Hao, Qingwei Li, Hengrui Liu, Qingchang Chen, Chang Peng, Chuqiu Zhang, Yuanjing Zou, Junwei Jia, Hui Li, Yanhua Wang, Bingmei Su, Yuqian Lai, Meiyun Chen, Haobo Chen, Zhong Feng, Guimin Zhang and Meicun Yao
Molecules 2024, 29(5), 1161; https://doi.org/10.3390/molecules29051161 - 05 Mar 2024
Viewed by 539
Abstract
1,3,6-Trigalloylglucose is a natural compound that can be extracted from the aqueous extracts of ripe fruit of Terminalia chebula Retz, commonly known as “Haritaki”. The potential anti-Helicobacter pylori (HP) activity of this compound has not been extensively studied or confirmed [...] Read more.
1,3,6-Trigalloylglucose is a natural compound that can be extracted from the aqueous extracts of ripe fruit of Terminalia chebula Retz, commonly known as “Haritaki”. The potential anti-Helicobacter pylori (HP) activity of this compound has not been extensively studied or confirmed in scientific research. This compound was isolated using a semi-preparative liquid chromatography (LC) system and identified through Ultra-high-performance liquid chromatography–MS/MS (UPLC-MS/MS) and Nuclear Magnetic Resonance (NMR). Its role was evaluated using Minimum inhibitory concentration (MIC) assay and minimum bactericidal concentration (MBC) assay, scanning electron microscope (SEM), inhibiting kinetics curves, urea fast test, Cell Counting Kit-8 (CCK-8) assay, Western blot, and Griess Reagent System. Results showed that this compound effectively inhibits the growth of HP strain ATCC 700392, damages the HP structure, and suppresses the Cytotoxin-associated gene A (Cag A) protein, a crucial factor in HP infection. Importantly, it exhibits selective antimicrobial activity without impacting normal epithelial cells GES-1. In vitro studies have revealed that 1,3,6-Trigalloylglucose acts as an anti-adhesive agent, disrupting the adhesion of HP to host cells, a critical step in HP infection. These findings underscore the potential of 1,3,6-Trigalloylglucose as a targeted therapeutic agent against HP infections. Full article
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52 pages, 3442 KiB  
Review
Exploring the Biological and Phytochemical Potential of Jordan’s Flora: A Review and Update of Eight Selected Genera from Mediterranean Region
by Manal I. Alruwad, Riham Salah El Dine, Abdallah M. Gendy, Manal M. Sabry and Hala M. El Hefnawy
Molecules 2024, 29(5), 1160; https://doi.org/10.3390/molecules29051160 - 05 Mar 2024
Viewed by 761
Abstract
Jordan’s flora is known for its rich diversity, with a grand sum of 2978 plant species that span 142 families and 868 genera across four different zones. Eight genera belonging to four different plant families have been recognized for their potential natural medicinal [...] Read more.
Jordan’s flora is known for its rich diversity, with a grand sum of 2978 plant species that span 142 families and 868 genera across four different zones. Eight genera belonging to four different plant families have been recognized for their potential natural medicinal properties within the Mediterranean region. These genera include Chrysanthemum L., Onopordum Vaill. Ex. L., Phagnalon Cass., and Senecio L. from the Asteraceae family, in addition to Clematis L. and Ranunculus L. from the Ranunculaceae family, Anchusa L. from the Boraginaceae family, and Eryngium L. from the Apiaceae family. The selected genera show a wide variety of secondary metabolites with encouraging pharmacological characteristics including antioxidant, antibacterial, cytotoxic, anti-inflammatory, antidiabetic, anti-ulcer, and neuroprotective actions. Further research on these genera and their extracts will potentially result in the formulation of novel and potent natural pharmaceuticals. Overall, Jordan’s rich flora provides a valuable resource for exploring and discovering new plant-based medicines. Full article
(This article belongs to the Section Natural Products Chemistry)
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21 pages, 5550 KiB  
Article
Experimental and Theoretical Investigation of External Electric-Field-Induced Crystallization of TKX-50 from Solution by Finite-Temperature String with Order Parameters as Collective Variables for Ionic Crystals
by Fude Ren, Xiaolei Wang, Qing Zhang, Xiaojun Wang, Lingling Chang and Zhiteng Zhang
Molecules 2024, 29(5), 1159; https://doi.org/10.3390/molecules29051159 - 05 Mar 2024
Viewed by 441
Abstract
External electric fields are an effective tool to induce phase transformations. The crystallization of ionic crystals from solution is a common phase transformation. However, understanding of mechanisms is poor at the molecular level. In this work, we carried out an experimental and theoretical [...] Read more.
External electric fields are an effective tool to induce phase transformations. The crystallization of ionic crystals from solution is a common phase transformation. However, understanding of mechanisms is poor at the molecular level. In this work, we carried out an experimental and theoretical investigation of the external electric-field-induced crystallization of TKX-50 from saturated formic acid solution by finite-temperature string (FTS) with order parameters (OPs) as collective variables for ionic crystals. The minimum-free-energy path was sketched by the string method in collective variables. The results show that the K-means clustering algorithm based on Euclidean distance and density weights can be used for enhanced sampling of the OPs in external electric-field-induced crystallization of ionic crystal from solution, which improves the conventional FTS. The crystallization from solution is a process of surface-mediated nucleation. The external electric field can accelerate the evolution of the string and decrease the difference in the potential of mean forces between the crystal and the transition state. Due to the significant change in OPs induced by the external electric field in nucleation, the crystalline quality was enhanced, which explains the experimental results that the external electric field enhanced the density, detonation velocity, and detonation pressure of TKX-50. This work provides an effective way to explore the crystallization of ionic crystals from solution at the molecular level, and it is useful for improving the properties of ionic crystal explosives by using external electric fields. Full article
(This article belongs to the Section Materials Chemistry)
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18 pages, 5673 KiB  
Article
Cellulose–Amine Porous Materials: The Effect of Activation Method on Structure, Textural Properties, CO2 Capture, and Recyclability
by Sarah Krupšová and Miroslav Almáši
Molecules 2024, 29(5), 1158; https://doi.org/10.3390/molecules29051158 - 05 Mar 2024
Viewed by 488
Abstract
CO2 capture via physical adsorption on activated porous carbons represents a promising solution towards effective carbon emission mitigation. Additionally, production costs can be further decreased by utilising biomass as the main precursor and applying energy-efficient activation. In this work, we developed novel [...] Read more.
CO2 capture via physical adsorption on activated porous carbons represents a promising solution towards effective carbon emission mitigation. Additionally, production costs can be further decreased by utilising biomass as the main precursor and applying energy-efficient activation. In this work, we developed novel cellulose-based activated carbons modified with amines (diethylenetriamine (DETA), 1,2-bis(3-aminopropylamino)ethane (BAPE), and melamine (MELA)) with different numbers of nitrogen atoms as in situ N-doping precursors. We investigated the effect of hydrothermal and thermal activation on the development of their physicochemical properties, which significantly influence the resulting CO2 adsorption capacity. This process entailed an initial hydrothermal activation of biomass precursor and amines at 240 °C, resulting in C+DETA, C+BAPE and C+MELA materials. Thermal samples (C+DETA (P), C+BAPE (P), and C+MELA (P)) were synthesised from hydrothermal materials by subsequent KOH chemical activation and pyrolysis in an inert argon atmosphere. Their chemical and structural properties were characterised using elemental analysis (CHN), infrared spectroscopy (IR), scanning electron microscopy (SEM), and thermogravimetric analysis (TG). The calculated specific surface areas (SBET) for thermal products showed higher values (998 m2 g−1 for C+DETA (P), 1076 m2 g−1 for C+BAPE (P), and 1348 m2 g−1 for C+MELA (P)) compared to the hydrothermal products (769 m2 g−1 for C+DETA, 833 m2 g−1 for C+BAPE, and 1079 m2 g−1 for C+MELA). Carbon dioxide adsorption as measured by volumetric and gravimetric methods at 0 and 25 °C, respectively, showed the opposite trend, which can be attributed to the reduced content of primary adsorption sites in the form of amine groups in thermal products. N2 and CO2 adsorption measurements were carried out on hydrothermal (C) and pyrolysed cellulose (C (P)), which showed a several-fold reduction in adsorption properties compared to amine-modified materials. The recyclability of C+MELA, which showed the highest CO2 adsorption capacity (7.34 mmol g−1), was studied using argon purging and thermal regeneration over five adsorption/desorption cycles. Full article
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