Molecules

8 pages, 2049 KiB

Open AccessCommunication

Density Function Theory Study on the Energy and Circular Dichroism Spectrum for Methylene-Linked Triazole Diads Depending on the Substitution Position and Conformation

by Masaki Nakahata and Akihito Hashidzume

Molecules 2024, 29(12), 2931; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122931 (registering DOI) - 20 Jun 2024

Abstract

Since the discovery of metal-catalyzed azide–alkyne cycloadditions, 1,2,3-triazoles have been widely used as linkers for various residues. 1,2,3-Triazole is an aromatic five-membered cyclic compound consisting of three nitrogen and two carbon atoms with large dipoles that absorb UV light. In the past decade, [...] Read more.

Since the discovery of metal-catalyzed azide–alkyne cycloadditions, 1,2,3-triazoles have been widely used as linkers for various residues. 1,2,3-Triazole is an aromatic five-membered cyclic compound consisting of three nitrogen and two carbon atoms with large dipoles that absorb UV light. In the past decade, we have been working on the synthesis of dense triazole polymers possessing many 1,2,3-triazole residues linked through a carbon atom in their backbone as a new type of functional polymer. Recently, we reported that stereoregular dense triazole uniform oligomers exhibit a circular dichroism signal based on the chiral arrangement of two neighboring 1,2,3-triazole residues. In this study, to investigate the chiral conformation of two neighboring 1,2,3-triazole residues in stereoregular dense triazole uniform oligomers, density functional theory (DFT) calculations were performed using 1,2,3-triazole diads with different substitution positions and conformations as model compounds and compared with our previous results. Full article

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

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18 pages, 2934 KiB

Open AccessArticle

Traceability Research on Geographic Erigeron breviscapus Based on High-Resolution Mass Spectrometry and Chemometric Analysis

by Jiao Zhang, Heng Tian, Tao Lin, Xiangzhong Huang and Hongcheng Liu

Molecules 2024, 29(12), 2930; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122930 (registering DOI) - 20 Jun 2024

Abstract

A method was developed to identify and trace the geographic sources of Erigeron breviscapus using high-resolution mass spectrometry and chemometrics. The representative samples were collected from the geographic area of Honghe Dengzhanhua and other areas in Yunnan province and Guizhou province. The data [...] Read more.

A method was developed to identify and trace the geographic sources of Erigeron breviscapus using high-resolution mass spectrometry and chemometrics. The representative samples were collected from the geographic area of Honghe Dengzhanhua and other areas in Yunnan province and Guizhou province. The data points could be determined well using the PCA and PLS-DA diagram. A total of 46 characteristic compounds were identified from Honghe Dengzhanhua and within Guizhou province, but 37 compounds were different from Honghe Dengzhanhua and other counties in Yunnan province. Two biomarkers were found from three regions. Their structures were inferred as 8-amino-7-oxononanoic acid and 8-hydroxyquinoline, and they had the same molecular composition. This may suggest that a possible synthesis pathway can be proven in the future. Full article

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12 pages, 2246 KiB

Open AccessArticle

Blue Phosphorescent Pt(II) Compound Based on Tetradentate Carbazole/2,3′-Bipyridine Ligand and Its Application in Organic Light-Emitting Diodes

by Hakjo Kim, Chan-Hee Ryu, Miso Hong, Kang Mun Lee, Unhyeok Jo and Youngjin Kang

Molecules 2024, 29(12), 2929; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122929 (registering DOI) - 20 Jun 2024

Abstract

The tetradentate ligand, merging a carbazole unit with high triplet energy and dimethoxy bipyridine, renowned for its exceptional quantum efficiency in coordination with metals like Pt, is expected to demonstrate remarkable luminescent properties. However, instances of tetradentate ligands such as bipyridine-based pyridylcarbazole derivatives [...] Read more.

The tetradentate ligand, merging a carbazole unit with high triplet energy and dimethoxy bipyridine, renowned for its exceptional quantum efficiency in coordination with metals like Pt, is expected to demonstrate remarkable luminescent properties. However, instances of tetradentate ligands such as bipyridine-based pyridylcarbazole derivatives remain exceptionally scarce in the current literature. In this study, we developed a tetradentate ligand based on carbazole and 2,3′-bipyridine and successfully complexed it with Pt(II) ions. This novel compound (1) serves as a sky-blue phosphorescent material for use in light-emitting diodes. Based on single-crystal X-ray analysis, compound 1 has a distorted square-planar geometry with a 5/6/6 backbone around the Pt(II) core. Bright sky-blue emissions were observed at 488 and 516 nm with photoluminescent quantum yields of 34% and a luminescent lifetime of 2.6 μs. TD-DFT calculations for 1 revealed that the electronic transition was mostly attributed to the ligand-centered (LC) charge transfer transition with a small contribution from the metal-to-ligand charge transfer transition (MLCT, ~14%). A phosphorescent organic light-emitting device was successfully fabricated using this material as a dopant, along with 3′-di(9H-carbazol-9-yl)-1,1′-biphenyl (mCBP) and 9-(3′-carbazol-9-yl-5-cyano-biphenyl-3-yl)-9H-carbazole-3-carbonitrile (CNmCBPCN) as mixed hosts. A maximum quantum efficiency of 5.2% and a current efficiency of 15.5 cd/A were obtained at a doping level of 5%. Full article

(This article belongs to the Special Issue Structure, Spectroscopic Characterization and Application of Crystals)

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16 pages, 3825 KiB

Open AccessArticle

Ciprofloxacin Removal via Acid-Modified Red Mud: Optimizing the Process, Analyzing the Adsorption Features, and Exploring the Underlying Mechanism

by Jingzhuan Shi, Wanqiong Wang, Ziyi Li and Yingjuan Shi

Molecules 2024, 29(12), 2928; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122928 (registering DOI) - 20 Jun 2024

Abstract

In this study, RM (red mud) was acidified with sulfuric acid, and the acidified ARM (acidified red mud) was utilized as an innovative adsorption material for treating antibiotic-containing wastewater. The adsorption conditions, kinetics, isotherms, thermodynamics, and mechanism of ARM for CIP (ciprofloxacin) were [...] Read more.

In this study, RM (red mud) was acidified with sulfuric acid, and the acidified ARM (acidified red mud) was utilized as an innovative adsorption material for treating antibiotic-containing wastewater. The adsorption conditions, kinetics, isotherms, thermodynamics, and mechanism of ARM for CIP (ciprofloxacin) were investigated. The characterization of the ARM involved techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), X-ray fluorescence (XRF), thermogravimetric analysis (TGA), and NH₃-TPD analysis. Adsorption studies employed a response surface methodology (RSM) for the experimental design. The results showed that ARM can absorb CIP effectively. The RSM optimal experiment indicated that the most significant model terms influencing adsorption capacity were solution pH, CIP initial concentration, and ARM dosage, under which the predicted maximum adsorption capacity achieved 7.30 mg/g. The adsorption kinetics adhered to a pseudo-second-order model, while equilibrium data fitted the Langmuir–Freundlich isotherm, yielding maximum capacity values of 7.35 mg/g. The adsorption process occurred spontaneously and absorbed heat, evidenced by ΔG^θ values between −83.05 and −91.50 kJ/mol, ΔS^θ at 281.6 J/mol/K, and ΔH^θ at 0.86 kJ/mol. Analysis using attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) indicated a complex reaction between the Al–O in the ARM and the ester group –COO in CIP. The C=O bond in CIP was likely to undergo a slight electrostatic interaction or be bound to the internal spherical surface of the ARM. The findings indicate that ARM is a promising and efficient adsorbent for CIP removal from wastewater. Full article

(This article belongs to the Section Analytical Chemistry)

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13 pages, 2059 KiB

Open AccessArticle

Synthesis and Characterisation of Core–Shell Microparticles Formed by Ni-Mn-Co Oxides

by Javier García-Alonso, Svitlana Krüger, Bilge Saruhan, David Maestre and Bianchi Méndez

Molecules 2024, 29(12), 2927; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122927 (registering DOI) - 20 Jun 2024

Abstract

In this work, core and core–shell microparticles formed by Ni-Mn-Co oxides with controlled composition were fabricated by an oxalate-assisted co-precipitation route, and their properties were analysed by diverse microscopy and spectroscopy techniques. The microparticles exhibit dimensions within the 2–6 μm range and mainly [...] Read more.

In this work, core and core–shell microparticles formed by Ni-Mn-Co oxides with controlled composition were fabricated by an oxalate-assisted co-precipitation route, and their properties were analysed by diverse microscopy and spectroscopy techniques. The microparticles exhibit dimensions within the 2–6 μm range and mainly consist of NiO and NiMn₂O₄, the latter being promoted as the temperature of the treatment increases, especially in the shell region of the microparticles. Aspects such as the shell dimensions, the vibrational modes of the spinel compounds primarily observed in the shell region, the oxidation states of the cations at the surface of the microparticles, and the achievement of a Ni-rich 811 core and a Mn-rich 631 shell were thoroughly evaluated and discussed in this work. Full article

(This article belongs to the Special Issue Exclusive Papers of Editorial Board Members and Invited Scholars in “Materials Chemistry”)

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1 pages, 169 KiB

Open AccessCorrection

Correction: Reyes Romero et al. Computer- and NMR-Aided Design of Small-Molecule Inhibitors of the Hub1 Protein. Molecules 2022, 27, 8282

by Atilio Reyes Romero, Katarzyna Kubica, Radoslaw Kitel, Ismael Rodríguez, Katarzyna Magiera-Mularz, Alexander Dömling, Tad A. Holak and Ewa Surmiak

Molecules 2024, 29(12), 2926; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122926 (registering DOI) - 20 Jun 2024

Abstract

In the published publication [...] Full article

13 pages, 5409 KiB

Open AccessArticle

A Dopamine Detection Sensor Based on Au-Decorated NiS₂ and Its Medical Application

by Chongchong Ma, Yixuan Wen, Yuqing Qiao, Kevin Z. Shen and Hongwen Yuan

Molecules 2024, 29(12), 2925; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122925 (registering DOI) - 20 Jun 2024

Abstract

This article reports a simple hydrothermal method for synthesizing nickel disulfide (NiS₂) on the surface of fluorine-doped tin oxide (FTO) glass, followed by the deposition of 5 nm Au nanoparticles on the electrode surface by physical vapor deposition. This process ensures [...] Read more.

This article reports a simple hydrothermal method for synthesizing nickel disulfide (NiS₂) on the surface of fluorine-doped tin oxide (FTO) glass, followed by the deposition of 5 nm Au nanoparticles on the electrode surface by physical vapor deposition. This process ensures the uniform distribution of Au nanoparticles on the NiS₂ surface to enhance its conductivity. Finally, an Au@NiS₂-FTO electrochemical biosensor is obtained for the detection of dopamine (DA). The composite material is characterized using transmission electron microscopy (TEM), UV-Vis spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical properties of the sensor are investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and time current curves in a 0.1 M PBS solution (pH = 7.3). In the detection of DA, Au@NiS₂-FTO exhibits a wide linear detection range (0.1~1000 μM), low detection limit (1 nM), and fast response time (0.1 s). After the addition of interfering substances, such as glucose, L-ascorbic acid, uric acid, CaCl₂, NaCl, and KCl, the electrode potential remains relatively unchanged, demonstrating its strong anti-interference capability. It also demonstrates strong sensitivity and reproducibility. The obtained Au@NiS₂-FTO provides a simple and easy-to-operate example for constructing nanometer catalysts with enzyme-like properties. These results provide a promising method utilizing Au coating to enhance the conductivity of transition metal sulfides. Full article

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15 pages, 1860 KiB

Open AccessArticle

Exploring the Antitumor Efficacy of N-Heterocyclic Nitrilotriacetate Oxidovanadium(IV) Salts on Prostate and Breast Cancer Cells

by Katarzyna Chmur, Aleksandra Tesmar, Magdalena Zdrowowicz, Damian Rosiak, Jarosław Chojnacki and Dariusz Wyrzykowski

Molecules 2024, 29(12), 2924; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122924 - 19 Jun 2024

Abstract

The crystal structures of two newly synthesized nitrilotriacetate oxidovanadium(IV) salts, namely [QH][VO(nta)(H₂O)](H₂O)₂ (I) and [(acr)H][VO(nta)(H₂O)](H₂O)₂ (II), were determined. Additionally, the cytotoxic effects of four N-heterocyclic nitrilotriacetate oxidovanadium(IV) salts—1,10-phenanthrolinium, [(phen)H][VO(nta)(H₂O)](H₂O) [...] Read more.

The crystal structures of two newly synthesized nitrilotriacetate oxidovanadium(IV) salts, namely [QH][VO(nta)(H₂O)](H₂O)₂ (I) and [(acr)H][VO(nta)(H₂O)](H₂O)₂ (II), were determined. Additionally, the cytotoxic effects of four N-heterocyclic nitrilotriacetate oxidovanadium(IV) salts—1,10-phenanthrolinium, [(phen)H][VO(nta)(H₂O)](H₂O)_0.5 (III), 2,2′-bipyridinium [(bpy)H][VO(nta)(H₂O)](H₂O) (IV), and two newly synthesized compounds (I) and (II)—were evaluated against prostate cancer (PC3) and breast cancer (MCF-7) cells. All the compounds exhibited strong cytotoxic effects on cancer cells and normal cells (HaCaT human keratinocytes). The structure–activity relationship analysis revealed that the number and arrangement of conjugated aromatic rings in the counterion had an impact on the antitumor effect. The compound (III), the 1,10-phenanthrolinium analogue, exhibited the greatest activity, whereas the acridinium salt (II), with a different arrangement of three conjugated aromatic rings, showed the lowest toxicity. The increased concentrations of the compounds resulted in alterations to the cell cycle distribution with different effects in MCF-7 and PC3 cells. In MCF-7 cells, compounds I and II were observed to block the G₂/M phase, while compounds III and IV were found to arrest the cell cycle in the G₀/G₁ phase. In PC3 cells, all compounds increased the rates of cells in the G₀/G₁ phase. Full article

(This article belongs to the Section Inorganic Chemistry)

23 pages, 2368 KiB

Open AccessArticle

Characterization and Performance of Peanut Shells in Caffeine and Triclosan Removal in Batch and Fixed-Bed Column Tests

by Cristina E. Almeida-Naranjo, Mayra Frutos, Victor H. Guerrero and Cristina Villamar-Ayala

Molecules 2024, 29(12), 2923; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122923 - 19 Jun 2024

Abstract

Peanut shells’ adsorption performance in caffeine and triclosan removal was studied. Peanut shells were analyzed for their chemical composition, morphology, and surface functional groups. Batch adsorption and fixed-bed column experiments were carried out with solutions containing 30 mg/L of caffeine and triclosan. The [...] Read more.

Peanut shells’ adsorption performance in caffeine and triclosan removal was studied. Peanut shells were analyzed for their chemical composition, morphology, and surface functional groups. Batch adsorption and fixed-bed column experiments were carried out with solutions containing 30 mg/L of caffeine and triclosan. The parameters examined included peanut shell particle size (120–150, 300–600, and 800–2000 µm), adsorbent dose (0.02–60 g/L), contact time (up to 180 min), bed height (4–8 cm), and hydraulic loading rate (2.0 and 4.0 m³/m²-day). After determining the optimal adsorption conditions, kinetics, isotherm, and breakthrough curve models were applied to analyze the experimental data. Peanut shells showed an irregular surface and consisted mainly of polysaccharides (around 70% lignin, cellulose, and hemicellulose), with a specific surface area of 1.7 m²/g and a pore volume of 0.005 cm³/g. The highest removal efficiencies for caffeine (85.6 ± 1.4%) and triclosan (89.3 ± 1.5%) were achieved using the smallest particles and 10.0 and 0.1 g/L doses over 180 and 45 min, respectively. Triclosan showed easier removal compared to caffeine due to its higher lipophilic character. The pseudo-second-order kinetics model provided the best fit with the experimental data, suggesting a chemisorption process between caffeine/triclosan and the adsorbent. Equilibrium data were well-described by the Sips model, with maximum adsorption capacities of 3.3 mg/g and 289.3 mg/g for caffeine and triclosan, respectively. In fixed-bed column adsorption tests, particle size significantly influenced efficiency and hydraulic behavior, with 120–150 µm particles exhibiting the highest adsorption capacity for caffeine (0.72 mg/g) and triclosan (143.44 mg/g), albeit with clogging issues. The experimental data also showed good agreement with the Bohart–Adams, Thomas, and Yoon–Nelson models. Therefore, the findings of this study highlight not only the effective capability of peanut shells to remove caffeine and triclosan but also their versatility as a promising option for water treatment and sanitation applications in different contexts. Full article

(This article belongs to the Special Issue Adsorbent Material for Water Treatment)

16 pages, 1300 KiB

Open AccessArticle

Enhanced Enzymatic Performance of Immobilized Pseudomonas fluorescens Lipase on ZIF-8@ZIF-67 and Its Application to the Synthesis of Neryl Acetate with Transesterification Reaction

by Qi Wang, Jian Xiong, Hanghang Xu, Wenyuan Sun, Xiaoxu Pan, Shixin Cui, Siting Lv and Yinling Zhang

Molecules 2024, 29(12), 2922; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122922 - 19 Jun 2024

Abstract

In this study, hybrid skeleton material ZIF-8@ZIF-67 was synthesized by the epitaxial growth method and then was utilized as a carrier for encapsulating Pseudomonas fluorescens lipase (PFL) through the co-precipitation method, resulting in the preparation of immobilized lipase (PFL@ZIF-8@ZIF-67). Subsequently, it was further [...] Read more.

In this study, hybrid skeleton material ZIF-8@ZIF-67 was synthesized by the epitaxial growth method and then was utilized as a carrier for encapsulating Pseudomonas fluorescens lipase (PFL) through the co-precipitation method, resulting in the preparation of immobilized lipase (PFL@ZIF-8@ZIF-67). Subsequently, it was further treated with glutaraldehyde to improve protein immobilization yield. Under optimal immobilization conditions, the specific hydrolytic activity of PFL@ZIF-8@ZIF-67 was 20.4 times higher than that of the free PFL. The prepared biocatalyst was characterized and analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR). Additionally, the thermal stability of PFL@ZIF-8@ZIF-67 at 50 °C was significantly improved compared to the free PFL. After 7 weeks at room temperature, PFL@ZIF-8@ZIF-67 retained 78% of the transesterification activity, while the free enzyme was only 29%. Finally, PFL@ZIF-8@ZIF-67 was applied to the neryl acetate preparation in a solvent-free system, and the yield of neryl acetate reached 99% after 3 h of reaction. After 10 repetitions, the yields of neryl acetate catalyzed by PFL@ZIF-8@ZIF-67 and the free PFL were 80% and 43%, respectively. Full article

11 pages, 1811 KiB

Open AccessArticle

Rapid Determination of Tetracyclines in Drinking and Environmental Waters using Fully Automatic Solid-Phase Extraction with Ultra-Performance Liquid Chromatography–Tandem Mass Spectrometry

by Tongtong Zhang, Xiangyang Zhang, Jiangmei Yu, Hongmei Hu, Pengfei He, Zhenhua Li, Yi Fang, Tiejun Li and Yuanming Guo

Molecules 2024, 29(12), 2921; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122921 - 19 Jun 2024

Abstract

The abuse and irrational use of tetracyclines (TCs) in human medicine and animal husbandry has become a serious concern, affecting the ecological environment and human health. The aim of this study was to develop a sensitive and selective method using fully automatic solid-phase [...] Read more.

The abuse and irrational use of tetracyclines (TCs) in human medicine and animal husbandry has become a serious concern, affecting the ecological environment and human health. The aim of this study was to develop a sensitive and selective method using fully automatic solid-phase extraction coupled with ultra-performance liquid chromatography–tandem mass spectrometry for the determination of twelve TCs in water. Four isotope-labeled internal standards for TCs were used to correct matrix effects. Several parameters affecting extraction efficiency were systematically optimized, and the optimum experimental conditions found were 1.0 L water sample with 0.5 g/L Na₂EDTA (pH 3.0) extracted and enriched by CNW HLB cartridge and eluted by 4 mL of acetone:methanol (v/v, 1:1). The enrichment factors were up to 798−1059 but only requiring about 60 min per six samples. Under the optimized conditions, the linearity of the method ranged from 0.2 to 100 μg/L for 12 TCs, the detection limits were as low as 0.01−0.15 ng/L, and the recoveries were in the range of 70%–118%, with relative standard deviations less than 15%. The developed method can be successfully utilized for the determination of 12 TCs in pure water, tap water, river water, and mariculture seawater. In summary, three and six TCs were detected in river water and mariculture seawater, respectively, with total concentrations of 0.074–0.520 ng/L (mean 0.248 ng/L) and 0.792–58.369 ng/L (12.629 ng/L), respectively. Tetracycline (TC) and oxytetracycline (OTC) were the dominant TCs in river water, while doxytetracycline (DXC) and OTC were dominant in mariculture seawater. Full article

(This article belongs to the Special Issue Advanced Analytical Techniques for the Detection and Quantification of Emerging Contaminants)

14 pages, 4225 KiB

Open AccessArticle

A Theoretical Investigation into the Oligomer Structure of Carbon Dots Formed from Small-Molecule Precursors

by Chunlan Li, Xu Zhu and Maotian Xu

Molecules 2024, 29(12), 2920; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122920 - 19 Jun 2024

Abstract

In-depth insights into the oligomers of carbon dots (CDs) prepared from small-molecule precursors are important in the study of the carbonization mechanism of CDs and for our knowledge of their complex structure. Herein, citric acid (CA) and ethylenediamine (EDA) were used as small-molecule [...] Read more.

In-depth insights into the oligomers of carbon dots (CDs) prepared from small-molecule precursors are important in the study of the carbonization mechanism of CDs and for our knowledge of their complex structure. Herein, citric acid (CA) and ethylenediamine (EDA) were used as small-molecule precursors to prepare CDs in an aqueous solution. The structure of oligomers acquired from CA and EDA in different molar ratios and their formation process were first studied using density functional theory, including the dispersion correction (DFT-D3) method. The results showed that the energy barrier of dimer cyclization was higher than that of its linear polymerization, but the free energy of the cyclized product was much lower than that of its reactant, and IPCA (5-oxo-1,-2,3,5-tetrahydroimidazo [1,2-a]pyridine-7-carboxylic acid) could therefore be obtained under certain conditions. The oligomers obtained from different molar ratios of EDA and CA were molecular clusters formed by short polyamide chains through intermolecular forces; with the exception of when the molar ratio of EDA to CA was 0.5, excessive CA did not undergo an amidation reaction but rather attained molecular clusters directly through intermolecular forces. These oligomers exhibited significant differences in their surface functional groups, which would affect the carbonization process and the surface structure of CDs. Full article

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14 pages, 4518 KiB

Open AccessArticle

Halogenated Boroxine K₂[B₃O₃F₄OH] Modulates Metabolic Phenotype and Autophagy in Human Bladder Carcinoma 5637 Cell Line

by Nikolina Elez-Burnjaković, Lejla Pojskić, Anja Haverić, Naida Lojo-Kadrić, Maida Hadžić Omanović, Ajla Smajlović, Svetoslav Kalaydjiev, Milka Maksimović, Bojan Joksimović and Sanin Haverić

Molecules 2024, 29(12), 2919; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122919 - 19 Jun 2024

Abstract

Halogenated boroxine K₂[B₃O₃F₄OH] (HB), an inorganic derivative of cyclic anhydride of boronic acid, is patented as a boron-containing compound with potential for the treatment of both benign and malignant skin changes. HB has effectively inhibited [...] Read more.

Halogenated boroxine K₂[B₃O₃F₄OH] (HB), an inorganic derivative of cyclic anhydride of boronic acid, is patented as a boron-containing compound with potential for the treatment of both benign and malignant skin changes. HB has effectively inhibited the growth of several carcinoma cell lines. Because of the growing interest in autophagy induction as a therapeutic approach in bladder carcinoma (BC), we aimed to assess the effects of HB on metabolic phenotype and autophagy levels in 5637 human bladder carcinoma cells (BC). Cytotoxicity was evaluated using the alamar blue assay, and the degree of autophagy was determined microscopically. Mitochondrial respiration and glycolysis were measured simultaneously. The relative expression of autophagy-related genes BECN1, P62, BCL-2, and DRAM1 was determined by real-time PCR. HB affected cell growth, while starvation significantly increased the level of autophagy in the positive control compared to the basal level of autophagy in the untreated negative control. In HB-treated cultures, the degree of autophagy was higher compared to the basal level, and metabolic phenotypes were altered; both glycolysis and oxidative phosphorylation (OXPHOS) were decreased by HB at 0.2 and 0.4 mg/mL. Gene expression was deregulated towards autophagy induction and expansion. In conclusion, HB disrupted the bioenergetic metabolism and reduced the intracellular survival potential of BC cells. Further molecular studies are needed to confirm these findings and investigate their applicative potential. Full article

(This article belongs to the Topic Bioactive Compounds and Therapeutics: Molecular Aspects, Metabolic Profiles, and Omics Studies)

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14 pages, 528 KiB

Open AccessFeature PaperArticle

Enantioselective Synthesis of the Active Sex Pheromone Components of the Female Lichen Moth, Lyclene dharma dharma, and Their Enantiomers

by Yun Zhou, Jianan Wang, Yueru Zhang, Xiaochen Fu, Hongqing Xie, Jinlong Han, Jianhua Zhang, Jiangchun Zhong and Chenggang Shan

Molecules 2024, 29(12), 2918; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122918 - 19 Jun 2024

Viewed by 1

Abstract

The Lichen moth, Lyclene dharma dharma (Arctiidae, Lithosiinae), plays a significant role in forest ecosystem dynamics. A concise and novel method to synthesize the active sex pheromone components, (S)-14-methyloctadecan-2-one ((S)-1), (S)-6-methyloctadecan-2-one (( [...] Read more.

The Lichen moth, Lyclene dharma dharma (Arctiidae, Lithosiinae), plays a significant role in forest ecosystem dynamics. A concise and novel method to synthesize the active sex pheromone components, (S)-14-methyloctadecan-2-one ((S)-1), (S)-6-methyloctadecan-2-one ((S)-2), and their enantiomers has been developed. Key steps in the synthesis include the use of Evans’ chiral auxiliaries, Grignard cross-coupling reactions, hydroboration–oxidation, and Wacker oxidation. The synthesized sex pheromone components hold potential value for studies on communication mechanisms, species identification, and ecological management. Full article

(This article belongs to the Special Issue Synthesis of Bioactive Compounds: Volume II)

12 pages, 1476 KiB

Open AccessArticle

Synthesis of Substituted 1,2-Dihydroisoquinolines by Palladium-Catalyzed Cascade Cyclization–Coupling of Trisubstituted Allenamides with Arylboronic Acids

by Masahiro Yoshida, Ryunosuke Imaji and Shinya Shiomi

Molecules 2024, 29(12), 2917; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122917 - 19 Jun 2024

Viewed by 91

Abstract

1,2-Dihydroisoquinolines are important compounds due to their biological and medicinal activities, and numerous approaches to their synthesis have been reported. Recently, we reported a facile synthesis of trisubstituted allenamides via N-acetylation followed by DBU-promoted isomerization, where various substituted allenamides were conveniently synthesized [...] Read more.

1,2-Dihydroisoquinolines are important compounds due to their biological and medicinal activities, and numerous approaches to their synthesis have been reported. Recently, we reported a facile synthesis of trisubstituted allenamides via N-acetylation followed by DBU-promoted isomerization, where various substituted allenamides were conveniently synthesized from readily available propargylamines with high efficiency. In light of this research background, we focused on the utility of this methodology for the synthesis of substituted 1,2-dihydroisoquinolines. In this study, a palladium-catalyzed cascade cyclization–coupling of trisubstituted allenamides containing a bromoaryl moiety with arylboronic acids is described. When N-acetyl diphenyl-substituted trisubstituted allenamide and phenylboronic acid were treated with 10 mol% of Pd(OAc)₂, 20 mol% of P(o-tolyl)₃, and 5 equivalents of NaOH in dioxane/H₂O (4/1) at 80 °C, the reaction proceeded to afford a substituted 1,2-dihydroisoquinoline. The reaction proceeded via intramolecular cyclization, followed by transmetallation with the arylboronic acid of the resulting allylpalladium intermediate. A variety of highly substituted 1,2-dihydroisoquinolines were concisely obtained using this methodology because the allenamides, as reaction substrates, were prepared from readily available propargylamines in one step. Full article

(This article belongs to the Special Issue Advances in Heterocyclic Synthesis)

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15 pages, 1942 KiB

Open AccessArticle

In Situ Self-Growth of a ZnO Nanorod Array on Nonwoven Fabrics for Empowering Superhydrophobic and Antibacterial Features

by Xiaoqi Yuan, Binghui Liu, Aili Yang, Peng Zhang, Wenjie Li and Yueyu Su

Molecules 2024, 29(12), 2916; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122916 - 19 Jun 2024

Viewed by 75

Abstract

ZnO nanorod nonwoven fabrics (ZNRN) were developed through hydrothermal synthesis to facilitate the prevention of the transmission of respiratory pathogens. The superhydrophobicity and antibacterial properties of ZNRN were improved through the response surface methodology. The synthesized material exhibited significant water repellency, indicated by [...] Read more.

ZnO nanorod nonwoven fabrics (ZNRN) were developed through hydrothermal synthesis to facilitate the prevention of the transmission of respiratory pathogens. The superhydrophobicity and antibacterial properties of ZNRN were improved through the response surface methodology. The synthesized material exhibited significant water repellency, indicated by a water contact angle of 163.9°, and thus demonstrated antibacterial rates of 91.8% for Escherichia coli (E. coli) and 79.75% for Staphylococcus aureus (S. aureus). This indicated that E. coli with thinner peptidoglycan may be more easily killed than S. aureus. This study identified significant effects of synthesis conditions on the antibacterial effectiveness, with comprehensive multivariate analyses elucidating the underlying correlations. In addition, the ZnO nanorod structure of ZNRN was characterized through SEM and XRD analyses. It endows the properties of superhydrophobicity (thus preventing bacteria from adhering to the ZNRN surface) and antibacterial capacity (thus damaging cells through the puncturing of these nanorods). Consequently, the alignment of two such features is desired to help support the development of personal protective equipment, which assists in avoiding the spread of respiratory infections. Full article

14 pages, 6403 KiB

Open AccessArticle

Ti₃C₂T_x Coated with TiO₂ Nanosheets for the Simultaneous Detection of Ascorbic Acid, Dopamine and Uric Acid

by Dengzhou Jia, Tao Yang, Kang Wang, Hongyang Wang, Enhui Wang, Kuo-Chih Chou and Xinmei Hou

Molecules 2024, 29(12), 2915; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122915 - 19 Jun 2024

Viewed by 105

Abstract

Two-dimensional MXenes have become an important material for electrochemical sensing of biomolecules due to their excellent electric properties, large surface area and hydrophilicity. However, the simultaneous detection of multiple biomolecules using MXene-based electrodes is still a challenge. Here, a simple solvothermal process was [...] Read more.

Two-dimensional MXenes have become an important material for electrochemical sensing of biomolecules due to their excellent electric properties, large surface area and hydrophilicity. However, the simultaneous detection of multiple biomolecules using MXene-based electrodes is still a challenge. Here, a simple solvothermal process was used to synthesis the Ti₃C₂T_x coated with TiO₂ nanosheets (Ti₃C₂T_x@TiO₂ NSs). The surface modification of TiO₂ NSs on Ti₃C₂T_x can effectively reduce the self-accumulation of Ti₃C₂T_x and improve stability. Glassy carbon electrode was modified by Ti₃C₂T_x@TiO₂ NSs (Ti₃C₂T_x@TiO₂ NSs/GCE) and was able simultaneously to detect dopamine (DA), ascorbic acid (AA) and uric acid (UA). Under concentrations ranging from 200 to 1000 μM, 40 to 300 μM and 50 to 400 μM, the limit of detection (LOD) is 2.91 μM, 0.19 μM and 0.25 μM for AA, DA and UA, respectively. Furthermore, Ti₃C₂T_x@TiO₂ NSs/GCE demonstrated remarkable stability and reliable reproducibility for the detection of AA/DA/UA. Full article

(This article belongs to the Special Issue Molecular Structural Analysis and Structure-Property Relationships in Materials Chemistry)

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18 pages, 8646 KiB

Open AccessArticle

Preliminary Screening on Antibacterial Crude Secondary Metabolites Extracted from Bacterial Symbionts and Identification of Functional Bioactive Compounds by FTIR, HPLC and Gas Chromatography–Mass Spectrometry

by Gobinath Chandrakasan, Juan Fernando García-Trejo, Ana Angelica Feregrino-Pérez, Humberto Aguirre-Becerra, Enrique Rico García and María Isabel Nieto-Ramírez

Molecules 2024, 29(12), 2914; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122914 - 19 Jun 2024

Viewed by 95

Abstract

Secondary metabolites, bioactive compounds produced by living organisms, can unveil symbiotic relationships in nature. In this study, soilborne entomopathogenic nematodes associated with symbiotic bacteria (Xenorhabdus stockiae and Photorhabdus luminescens) were extracted from solvent supernatant containing secondary metabolites, demonstrating significant inhibitory effects [...] Read more.

Secondary metabolites, bioactive compounds produced by living organisms, can unveil symbiotic relationships in nature. In this study, soilborne entomopathogenic nematodes associated with symbiotic bacteria (Xenorhabdus stockiae and Photorhabdus luminescens) were extracted from solvent supernatant containing secondary metabolites, demonstrating significant inhibitory effects against E. coli, S. aureus, B. subtilus, P. mirabilis, E. faecalis, and P. stutzeri. The characterization of these secondary metabolites by Fourier transforms infrared spectroscopy revealed amine groups of proteins, hydroxyl and carboxyl groups of polyphenols, hydroxyl groups of polysaccharides, and carboxyl groups of organic acids. Furthermore, the obtained crude extracts were analyzed by high-performance liquid chromatography for the basic identification of potential bioactive peptides. Gas chromatography–mass spectrometry analysis of ethyl acetate extracts from Xenorhabdus stockiae identified major compounds including nonanoic acid derivatives, proline, paromycin, octodecanal derivatives, trioxa-5-aza-1-silabicyclo, 4-octadecenal, methyl ester, oleic acid, and 1,2-benzenedicarboxylicacid. Additional extraction from Photorhabdus luminescens yielded functional compounds such as indole-3-acetic acid, phthalic acid, 1-tetradecanol, nemorosonol, 1-eicosanol, and unsaturated fatty acids. These findings support the potential development of novel natural antimicrobial agents for future pathogen suppression. Full article

(This article belongs to the Special Issue Antimicrobial Properties of Natural Products (Volume Ⅱ))

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14 pages, 4184 KiB

Open AccessArticle

FeOOH Nanosheets Coupled with ZnCdS Nanoparticles for Highly Improved Photocatalytic Degradation of Organic Dyes and Tetracycline in Water

by Jingren Yang

Molecules 2024, 29(12), 2913; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122913 - 19 Jun 2024

Viewed by 135

Abstract

Developing a low-cost and highly efficient semiconductor photocatalyst for the decomposition of organic pollutants and antibiotics is highly desirable. Herein, FeOOH nanosheets were prepared using a liquid-phase stirring technique and combined with ZnCdS (ZCS) nanoparticles to construct FeOOH/ZCS nanocomposite photocatalysts. The photocatalytic efficiency [...] Read more.

Developing a low-cost and highly efficient semiconductor photocatalyst for the decomposition of organic pollutants and antibiotics is highly desirable. Herein, FeOOH nanosheets were prepared using a liquid-phase stirring technique and combined with ZnCdS (ZCS) nanoparticles to construct FeOOH/ZCS nanocomposite photocatalysts. The photocatalytic efficiency of the FeOOH/ZCS nanocomposite was evaluated for the decomposition of various pollutants, including rhodamine B, methylene Blue, and tetracycline. The FeOOH/ZCS nanocomposite exhibited significantly higher photocatalytic performance for the decomposition of various organics. Moreover, the optimized FeOOH/ZCS retained more than 90% of its initial photocatalytic activity even after five successful runs. Radical quenching test and electron spin resonance (ESR) analysis revealed that hydroxyl radicals (^•OH) play a dominant role for the decomposition of organics. The FeOOH/ZCS Z-scheme heterojunction significantly facilitates higher charge transfer efficiency and the generation of reactive radicals, resulting in excellent photocatalytic degradation performance. This work offers a new approach to synthesis FeOOH-based photocatalyst for the elimination of organics and antibiotics in water. Full article

(This article belongs to the Section Applied Chemistry)

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13 pages, 1429 KiB

Open AccessArticle

EMPDTA: An End-to-End Multimodal Representation Learning Framework with Pocket Online Detection for Drug–Target Affinity Prediction

by Dingkai Huang and Jiang Xie

Molecules 2024, 29(12), 2912; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122912 - 19 Jun 2024

Viewed by 93

Abstract

Accurately predicting drug–target interactions is a critical yet challenging task in drug discovery. Traditionally, pocket detection and drug–target affinity prediction have been treated as separate aspects of drug–target interaction, with few methods combining these tasks within a unified deep learning system to accelerate [...] Read more.

Accurately predicting drug–target interactions is a critical yet challenging task in drug discovery. Traditionally, pocket detection and drug–target affinity prediction have been treated as separate aspects of drug–target interaction, with few methods combining these tasks within a unified deep learning system to accelerate drug development. In this study, we propose EMPDTA, an end-to-end framework that integrates protein pocket prediction and drug–target affinity prediction to provide a comprehensive understanding of drug–target interactions. The EMPDTA framework consists of three main modules: pocket online detection, multimodal representation learning for affinity prediction, and multi-task joint training. The performance and potential of the proposed framework have been validated across diverse benchmark datasets, achieving robust results in both tasks. Furthermore, the visualization results of the predicted pockets demonstrate accurate pocket detection, confirming the effectiveness of our framework. Full article

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

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14 pages, 10997 KiB

Open AccessArticle

Selective Heterogeneous Fenton Degradation of Formaldehyde Using the Fe-ZSM-5 Catalyst

by Peiguo Zhou, Jiaxin Hou, Donghui Zhang, Ziqiao Liao, Liping Yang, Wenjing Yang, Xin Ru and Zongbiao Dai

Molecules 2024, 29(12), 2911; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122911 - 19 Jun 2024

Viewed by 100

Abstract

As a toxic Volatile Organic Pollutant (TVOC), formaldehyde has a toxic effect on microorganisms, consequently inhibiting the biochemical process of formaldehyde wastewater treatment. Therefore, the selective degradation of formaldehyde is of great significance in achieving high-efficiency and low-cost formaldehyde wastewater treatment. This study [...] Read more.

As a toxic Volatile Organic Pollutant (TVOC), formaldehyde has a toxic effect on microorganisms, consequently inhibiting the biochemical process of formaldehyde wastewater treatment. Therefore, the selective degradation of formaldehyde is of great significance in achieving high-efficiency and low-cost formaldehyde wastewater treatment. This study constructed a heterogeneous Fe-ZSM-5/H₂O₂ Fenton system f or the selective degradation of target compounds. By immobilizing Fe³⁺ onto the surface of a ZSM-5 molecular sieve, Fe-ZSM-5 was prepared successfully. XRD, BET and FT-IR spectral studies showed that Fe-ZSM-5 was mainly composed of micropores. The influences of different variables on formaldehyde-selective heterogeneous Fenton degradation performance were studied. The 93.7% formaldehyde degradation and 98.2% selectivity of formaldehyde compared with glucose were demonstrated in the optimized Fenton system after 360 min. Notably, the resultant selective Fenton oxidation system had a wide range of pH suitability, from 3.0 to 10.0. Also, the Fe-ZSM-5 was used in five consecutive cycles without a significant drop in formaldehyde degradation efficiency. The use of reactive oxygen species scavengers indicated that the hydroxyl radical was the primary active species responsible for degrading formaldehyde. Furthermore, great degradation performance was acquired with high concentrations of formaldehyde for this system, and the degradation efficiency was more than 95.0%. Full article

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27 pages, 2771 KiB

Open AccessReview

The Potential of Cold Atmospheric Pressure Plasmas for the Direct Degradation of Organic Pollutants Derived from the Food Production Industry

by Piotr Cyganowski, Dominik Terefinko, Agata Motyka-Pomagruk, Weronika Babinska-Wensierska, Mujahid Ameen Khan, Tymoteusz Klis, Wojciech Sledz, Ewa Lojkowska, Piotr Jamroz, Pawel Pohl, Magda Caban, Monica Magureanu and Anna Dzimitrowicz

Molecules 2024, 29(12), 2910; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122910 - 19 Jun 2024

Viewed by 157

Abstract

Specialized chemicals are used for intensifying food production, including boosting meat and crop yields. Among the applied formulations, antibiotics and pesticides pose a severe threat to the natural balance of the ecosystem, as they either contribute to the development of multidrug resistance among [...] Read more.

Specialized chemicals are used for intensifying food production, including boosting meat and crop yields. Among the applied formulations, antibiotics and pesticides pose a severe threat to the natural balance of the ecosystem, as they either contribute to the development of multidrug resistance among pathogens or exhibit ecotoxic and mutagenic actions of a persistent character. Recently, cold atmospheric pressure plasmas (CAPPs) have emerged as promising technologies for degradation of these organic pollutants. CAPP-based technologies show eco-friendliness and potency for the removal of organic pollutants of diverse chemical formulas and different modes of action. For this reason, various types of CAPP-based systems are presented in this review and assessed in terms of their constructions, types of discharges, operating parameters, and efficiencies in the degradation of antibiotics and persistent organic pollutants. Additionally, the key role of reactive oxygen and nitrogen species (RONS) is highlighted. Moreover, optimization of the CAPP operating parameters seems crucial to effectively remove contaminants. Finally, the CAPP-related paths and technologies are further considered in terms of biological and environmental effects associated with the treatments, including changes in antibacterial properties and toxicity of the exposed solutions, as well as the potential of the CAPP-based strategies for limiting the spread of multidrug resistance. Full article

(This article belongs to the Special Issue Removal of Pharmaceuticals from Contaminated Water, Wastewater and Sediments)

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11 pages, 6064 KiB

Open AccessArticle

Stereoselective Solid-State Synthesis of Biologically Active Cyclobutane and Dicyclobutane Isomers via Conformation Blocking and Transference

by Zhen Qin, Yunqiong Gu, Davidjames Young, Feilong Hu and Zhirong Luo

Molecules 2024, 29(12), 2909; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122909 - 19 Jun 2024

Viewed by 103

Abstract

Conformations in the solid state are typically fixed during crystallization. Transference of “frozen” C=C conformations in 3,5-bis((E)-2-(pyridin-4-yl)vinyl)methylbenzene (CH₃-3,5-bpeb) by photodimerization selectively yielded cyclobutane and dicyclobutane isomers, one of which (Isomer 2) exhibited excellent in vitro anti-cancer activity towards T-24, 7402, MGC803, [...] Read more.

Conformations in the solid state are typically fixed during crystallization. Transference of “frozen” C=C conformations in 3,5-bis((E)-2-(pyridin-4-yl)vinyl)methylbenzene (CH₃-3,5-bpeb) by photodimerization selectively yielded cyclobutane and dicyclobutane isomers, one of which (Isomer 2) exhibited excellent in vitro anti-cancer activity towards T-24, 7402, MGC803, HepG-2, and HeLa cells. Full article

(This article belongs to the Special Issue Metal Organic Frameworks (MOFs) for Sensing Applications)

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17 pages, 6187 KiB

Open AccessArticle

Selective Adsorption of Sr(II) from Aqueous Solution by Na₃FePO₄CO₃: Experimental and DFT Studies

by Yudong Xie, Xiaowei Wang, Jinfeng Men, Min Zhu, Chengqiang Liang, Hao Ding, Zhihui Du, Ping Bao and Zhilin Hu

Molecules 2024, 29(12), 2908; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122908 - 19 Jun 2024

Viewed by 137

Abstract

The efficient segregation of radioactive nuclides from low-level radioactive liquid waste (LLRW) is paramount for nuclear emergency protocols and waste minimization. Here, we synthesized Na₃FePO₄CO₃ (NFPC) via a one-pot hydrothermal method and applied it for the first time [...] Read more.

The efficient segregation of radioactive nuclides from low-level radioactive liquid waste (LLRW) is paramount for nuclear emergency protocols and waste minimization. Here, we synthesized Na₃FePO₄CO₃ (NFPC) via a one-pot hydrothermal method and applied it for the first time to the selective separation of Sr²⁺ from simulated LLRW. Static adsorption experimental results indicated that the distribution coefficient K_d remained above 5000 mL·g⁻¹, even when the concentration of interfering ions was more than 40 times that of Sr²⁺. Furthermore, the removal efficiency of Sr²⁺ showed no significant change within the pH range of 4 to 9. The adsorption of Sr²⁺ fitted the pseudo-second-order kinetic model and the Langmuir isotherm model, with an equilibrium time of 36 min and a maximum adsorption capacity of 99.6 mg·g⁻¹. Notably, the adsorption capacity was observed to increment marginally with an elevation in temperature. Characterization analyses and density functional theory (DFT) calculations elucidated the adsorption mechanism, demonstrating that Sr²⁺ initially engaged in an ion exchange reaction with Na⁺. Subsequently, Sr²⁺ coordinated with four oxygen atoms on the NFPC (100) facet, establishing a robust Sr-O bond via orbital hybridization. Full article

(This article belongs to the Special Issue A New Perspective on the Determination and Removal of Pollutants in the Environment)

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21 pages, 1576 KiB

Open AccessArticle

Copper (II) Level in Musts Affects Acetaldehyde Concentration, Phenolic Composition, and Chromatic Characteristics of Red and White Wines

by Francesco Errichiello, Luigi Picariello, Martino Forino, Giuseppe Blaiotta, Ernesto Petruzziello, Luigi Moio and Angelita Gambuti

Molecules 2024, 29(12), 2907; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122907 - 19 Jun 2024

Viewed by 131

Abstract

Copper (II), a vital fungicide in organic viticulture, also acts as a wine oxidation catalyst. However, limited data are currently available on the impact that maximum allowed copper (II) ion doses in wine grapes at harvest can have on aged wine quality. This [...] Read more.

Copper (II), a vital fungicide in organic viticulture, also acts as a wine oxidation catalyst. However, limited data are currently available on the impact that maximum allowed copper (II) ion doses in wine grapes at harvest can have on aged wine quality. This was the focus of the present study. We investigated the copper (II) effects by producing both white and red wines from musts containing three initial metal concentrations according to the limits set for organic farming. In detail, the influence of copper (II) on fermentation evolution, chromatic characteristics, and phenolic compounds was evaluated. Interestingly, the white wine obtained with the highest permitted copper (II) dose initially exceeded the concentration of 1.0 mg/L at fermentation completion. However, after one year of storage, the copper (II) content fell below 0.2 ± 0.01 mg/L. Conversely, red wines showed copper (II) levels below 1.0 mg/L at the end of fermentation, but the initial copper (II) level in musts significantly affected total native anthocyanins, color intensity, hue, and acetaldehyde concentration. After 12-month aging, significant differences were observed in polymeric pigments, thus suggesting a potential long-term effect of copper (II) on red wine color stability. Full article

(This article belongs to the Section Food Chemistry)

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15 pages, 4642 KiB

Open AccessArticle

Magnetic Titanium Dioxide Nanocomposites as a Recyclable SERRS Substrate for the Ultrasensitive Detection of Histidine

by Hailin Wen, Miao Li, Chao-Yang Zhao, Tao Xu, Shuang Fu, Huimin Sui and Cuiyan Han

Molecules 2024, 29(12), 2906; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122906 - 19 Jun 2024

Viewed by 119

Abstract

A highly sensitive, selective and recyclable histidine detection method based on magnetic Fe₃O₄@mTiO₂ (M-TiO₂) nanocomposites with SERRS was developed. Mesoporous M-TiO₂ nanoparticles were functionalized with 4-aminothiophenol and then coupled with histidine through an azo coupling [...] Read more.

A highly sensitive, selective and recyclable histidine detection method based on magnetic Fe₃O₄@mTiO₂ (M-TiO₂) nanocomposites with SERRS was developed. Mesoporous M-TiO₂ nanoparticles were functionalized with 4-aminothiophenol and then coupled with histidine through an azo coupling reaction in 5 min, producing the corresponding azo compound. The strong and specific SERRS response of the azo product allowed for ultrasensitive and selective detection for histidine with an M-TiO₂ device loaded with Ag NPs due to the molecular resonance effect and plasmonic effect of Ag NPs under a 532 nm excitation laser. The sensitivity was further enhanced with the magnetic enrichment of M-TiO₂. The limit of detection (LOD) was as low as 8.00 × 10⁻¹² mol/L. The M-TiO₂ demonstrated applicability towards histidine determination in human urine without any sample pretreatment. Additionally, the M-TiO₂ device can be recycled for 3 cycles with the photodegradation of the azo product under UV irradiation due to TiO₂-assisted and plasmon-enhanced photocatalysis. In summary, a multifunctional and recyclable M-TiO₂ device was synthesized based on azo coupling and SERRS spectroscopy for ultra-sensitive and specific histidine sensing. In addition, the proposed system demonstrated the potential for the multiplex determination of toxic compounds in the fields of food safety, industrial production and environmental protection, which benefit from the fingerprint property and universality of SERRS. Full article

(This article belongs to the Special Issue Advances in the Applications of Surface Enhanced Raman Scattering)

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16 pages, 6474 KiB

Open AccessArticle

1,6-Nucleophilic Di- and Trifluoromethylation of para-Quinone Methides with Me₃SiCF₂H/Me₃SiCF₃ Facilitated by CsF/18-Crown-6

by Dingben Chen, Ling Huang, Mingyu Liang, Xiaojing Chen, Dongdong Cao, Pan Xiao, Chuanfa Ni and Jinbo Hu

Molecules 2024, 29(12), 2905; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122905 - 19 Jun 2024

Viewed by 103

Abstract

The direct 1,6-nucleophilic difluoromethylation, trifluoromethylation, and difluoroalkylation of para-quinone methides (p-QMs) with Me₃SiRf (Rf = CF₂H, CF₃, CF₂CF₃, CF₂COOEt, and CF₂SPh) under mild conditions are described. [...] Read more.

The direct 1,6-nucleophilic difluoromethylation, trifluoromethylation, and difluoroalkylation of para-quinone methides (p-QMs) with Me₃SiRf (Rf = CF₂H, CF₃, CF₂CF₃, CF₂COOEt, and CF₂SPh) under mild conditions are described. Although Me₃SiCF₂H shows lower reactivity than Me₃SiCF₃, it can react with p-QMs promoted by CsF/18-Crown-6 to give structurally diverse difluoromethyl products in good yields. The products can then be further converted into fluoroalkylated para-quinone methides and α-fluoroalkylated diarylmethanes. Full article

(This article belongs to the Special Issue Advances in Modern Fluorine Chemistry)

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29 pages, 6531 KiB

Open AccessReview

Five Underutilized Ecuadorian Fruits and Their Bioactive Potential as Functional Foods and in Metabolic Syndrome: A Review

by Rodrigo Duarte-Casar, Nancy González-Jaramillo, Natalia Bailon-Moscoso, Marlene Rojas-Le-Fort and Juan Carlos Romero-Benavides

Molecules 2024, 29(12), 2904; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122904 - 19 Jun 2024

Viewed by 346

Abstract

The Ecuadorian Amazon harbors numerous wild and cultivated species used as food, many of which are underutilized. This review explores the bioactive potential of five such fruits—Borojó (Alibertia patinoi); Chonta (Bactris gasipaes); Arazá (Eugenia stipitata); Amazon grape [...] Read more.

The Ecuadorian Amazon harbors numerous wild and cultivated species used as food, many of which are underutilized. This review explores the bioactive potential of five such fruits—Borojó (Alibertia patinoi); Chonta (Bactris gasipaes); Arazá (Eugenia stipitata); Amazon grape (Pourouma cecropiifolia), a wild edible plant; and Cocona (Solanum sessiliflorum)—and their applications against metabolic syndrome. This study highlights their health-promoting ingredients and validates traditional medicinal properties, emphasizing their significance in improving health and mitigating the effects of the Western diet. These fruits, integral to Ecuadorian cuisine, are consumed fresh and processed. Chonta is widely cultivated but less prominent than in pre-Hispanic times, Borojó is known for its aphrodisiac properties, Cocona is traditional in northern provinces, Arazá is economically significant in food products, and Amazon grape is the least utilized and researched. The fruits are rich in phenolics (A. patinoi, E. stipitata) and carotenoids (B. gasipaes, E. stipitata), which are beneficial in controlling metabolic syndrome. This study advocates for more research and product development, especially for lesser-known species with high phenolic and anthocyanin content. This research underscores the economic, cultural, and nutritional value of these fruits, promoting their integration into modern diets and contributing to sustainable agriculture, cultural preservation, and public health through functional foods and nutraceuticals. Full article

(This article belongs to the Special Issue Bioactive Properties and Chemical Composition of Wild Edible Species)

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14 pages, 2294 KiB

Open AccessReview

Superluminal Molecular and Nanomaterial Probes Based on Fast Ions or Electrons

by Alexander Morrison, Vashista Muralidhara Srivatsa and Khashayar Ghandi

Molecules 2024, 29(12), 2903; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122903 - 19 Jun 2024

Viewed by 209

Abstract

This work reviews the progression of chemical analysis via Cherenkov emissions, i.e., Cherenkov Photometry and Cherenkov Emission Spectroscopy, from its introduction in the literature up to modern developments. In presenting the history of this field, we aim to consolidate the literature, both for [...] Read more.

This work reviews the progression of chemical analysis via Cherenkov emissions, i.e., Cherenkov Photometry and Cherenkov Emission Spectroscopy, from its introduction in the literature up to modern developments. In presenting the history of this field, we aim to consolidate the literature, both for reference and contextualization. We present an argument aiming to untangle why this corner of research has seen little progress while so many other directly related aspects of Cherenkov research have flourished, as well as speak to the progress of the field in recent years and prospective direction in years to come. Full article

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39 pages, 1973 KiB

Open AccessReview

Research Progress on Ti₃C₂T_x-Based Composite Materials in Antibacterial Field

by Huangqin Chen, Yilun Wang, Xuguang Chen, Zihan Wang, Yue Wu, Qiongqiao Dai, Wenjing Zhao, Tian Wei, Qingyuan Yang, Bin Huang and Yuesheng Li

Molecules 2024, 29(12), 2902; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules29122902 - 18 Jun 2024

Viewed by 308

Abstract

The integration of two-dimensional Ti₃C₂T_x nanosheets and other materials offers broader application options in the antibacterial field. Ti₃C₂T_x-based composites demonstrate synergistic physical, chemical, and photodynamic antibacterial activity. In this review, we aim [...] Read more.

The integration of two-dimensional Ti₃C₂T_x nanosheets and other materials offers broader application options in the antibacterial field. Ti₃C₂T_x-based composites demonstrate synergistic physical, chemical, and photodynamic antibacterial activity. In this review, we aim to explore the potential of Ti₃C₂T_x-based composites in the fabrication of an antibiotic-free antibacterial agent with a focus on their systematic classification, manufacturing technology, and application potential. We investigate various components of Ti₃C₂T_x-based composites, such as metals, metal oxides, metal sulfides, organic frameworks, photosensitizers, etc. We also summarize the fabrication techniques used for preparing Ti₃C₂T_x-based composites, including solution mixing, chemical synthesis, layer-by-layer self-assembly, electrostatic assembly, and three-dimensional (3D) printing. The most recent developments in antibacterial application are also thoroughly discussed, with special attention to the medical, water treatment, food preservation, flexible textile, and industrial sectors. Ultimately, the future directions and opportunities are delineated, underscoring the focus of further research, such as elucidating microscopic mechanisms, achieving a balance between biocompatibility and antibacterial efficiency, and investigating effective, eco-friendly synthesis techniques combined with intelligent technology. A survey of the literature provides a comprehensive overview of the state-of-the-art developments in Ti₃C₂T_x-based composites and their potential applications in various fields. This comprehensive review covers the variety, preparation methods, and applications of Ti₃C₂T_x-based composites, drawing upon a total of 171 English-language references. Notably, 155 of these references are from the past five years, indicating significant recent progress and interest in this research area. Full article

(This article belongs to the Special Issue The Way Forward in MXenes Materials)

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