Molecules

19 pages, 2502 KiB

Open AccessArticle

Broad-Spectrum Legionaminic Acid-Specific Antibodies in Pooled Human IgGs Revealed by Glycan Microarrays with Chemoenzymatically Synthesized Nonulosonosides

by Anoopjit Singh Kooner, Hai Yu, Shani Leviatan Ben-Arye, Vered Padler-Karavani and Xi Chen

Molecules 2024, 29(16), 3980; https://doi.org/10.3390/molecules29163980 - 22 Aug 2024

Viewed by 1109

Abstract

The presence and the level of antibodies in human sera against bacterial glycans are indications of prior encounters with similar antigens and/or the bacteria that express them by the immune system. An increasing number of pathogenic bacteria that cause human diseases have been [...] Read more.

The presence and the level of antibodies in human sera against bacterial glycans are indications of prior encounters with similar antigens and/or the bacteria that express them by the immune system. An increasing number of pathogenic bacteria that cause human diseases have been shown to express polysaccharides containing a bacterial nonulosonic acid called 5,7-di-N-acetyllegionaminic acid (Leg5,7Ac₂). To investigate the immune recognition of Leg5,7Ac₂, which is critical for the fight against bacterial infections, a highly effective chemoenzymatic synthon strategy was applied to construct a library of α2–3/6-linked Leg5,7Ac₂-glycans via their diazido-derivatives (Leg5,7diN₃-glycans) formed by efficient one-pot three-enzyme (OP3E) synthetic systems from a diazido-derivative of a six-carbon monosaccharide precursor. Glycan microarray studies using this synthetic library of a Leg5,7Ac₂-capped collection of diverse underlying glycan carriers and their matched sialoside counterparts revealed specific recognition of Leg5,7Ac₂ by human IgG antibodies pooled from thousands of healthy donors (IVIG), suggesting prior human encounters with Leg5,7Ac₂-expressing pathogenic bacteria at the population level. These biologically relevant Leg5,7Ac₂-glycans and their immune recognition assays are important tools to begin elucidating their biological roles, particularly in the context of infection and host–pathogen interactions. Full article

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

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Figure 1
Structures of N-acetylneuraminic acid (Neu5Ac, 1); 5,7-di-N-acetyllegionaminic acid (Leg5,7Ac2, 2); Leg5,7Ac2 precursor 6deoxyMan2,4diNAc (3); and Leg5,7Ac2 chemoenzymatic synthon 6deoxyMan2,4diN3 (4). Full article ">Figure 2
Glycan microarray binding studies against Leg5,7Ac2-glycans and sialoglycan counterparts. (a) Glycan microarrays fabricated with Leg5,7Ac2-glycans and sialoglycans (Neu5Gc/Neu5Ac/Neu5Ac7NAc-glycans) were examined with IVIG (IVIG-1 Privigen or IVIG-2 OMRIgG-AR; 50 μg/sub-array), anti-Neu5Gc IgY (αNeu5Gc; 1:7000), SiaFindα2-6 (0.25 μg), and 11 biotinylated plant lectins (2 μg each: MAL-II, LEL, PNA, WGA, VVL, AAL, LcH, ConA, ECL, PSA, and GSL-II) at 100 μL/subarray in blocking buffer (PBS, 1% ovalbumin; the assay buffers for plant lectins also contained divalent cations, see ESI), then detected with Cy3-anti-human IgG (0.4 ng/μL) for IVIG, Cy3-anti-chicken IgY (0.375 ng/μL) for IgY, and Cy3-sterptavidin (1.2 ng/μL) for Sia-Find and Lectins, at each 200 μL/sub-array. Slides were scanned and analyzed for Relative Fluorescence Units (RFU), which were plotted as a heatmap. (b) Binding of IVIG (average IVIG-1 and IVIG-2) to Leg5,7Ac2-glycans compared to Neu5Ac7NAc-glycans, non-Sia glycans, and glycans terminated with Neu5Ac, Neu5,9Ac2, Neu5Gc, and Neu5Gc9Ac (mixed effects analysis, with the Geisser-Greenhouse correction and individual variances computed for each comparison using uncorrected Fisher’s LSD; * p = 0.04, ** p = 0.001, *** p < 0.001). Full article ">Figure 3
Characterization of IVIG binding to Leg5,7Ac2-glycans. (a) Binding of IVIG-2 (OMRIgG-AR) to glycan microarray at 50 μg/sub-array, after pre-treatment of the arrays with/without 10 mU sialidase (Arthrobacter ureafaciens sialidase, AUS; Clostridium perfringens neuraminidase; NCP) for 2 h at 37 °C, then detected with 0.4 ng/μL Cy3-anti-human IgG. Slides were scanned, analyzed, and RFU-plotted (mixed-effects analysis, with the Geisser-Greenhouse correction, and individual variances computed for each comparison using uncorrected Fisher’s LSD; ns = non-significant p > 0.05 (p = 0.6132, 0.3334, 0.7287, 0.7454 None vs AUS/NCP in Leg/Neu, respectively), * p = 0.02, ** p < 0.003). (b) Averaged binding of IVIG-1 and IVIG-2 to Leg5,7Ac2-glycans on glycan microarrays in the presence of selected competing glycans. IVIG (IVIG-1 Privigen or IVIG-2 OMRIgG-AR, 50 μg/sub-array) were pre-incubated for 2 h on ice with various inhibitors on each sub-array, including 2-O-methyl-αNeu5Gc (Gc2Me; 4 mM), glycan ID-51 (Core1β, 2 mM), mouse serum glycopeptides (mGP, containing N/O-glycans [<a href="#B46-molecules-29-03980" class="html-bibr">46</a>], 0.45 mM), glycan ID-502 (Leg5,7Ac2α3Core1β, 1 mM), and glycan ID-508 (Leg5,7Ac2α6Core1β; 1 mM). Then, binding of the pre-complexed IVIG was examined and detected with 0.4 ng/μL Cy3-anti-human IgG. Slides were scanned, analyzed, and RFU results were plotted. Percent binding to each glycan was calculated as a ratio to binding of IVIG without inhibitor (none, 100% binding). (c) Statistical analysis of inhibition of IVIG binding to Leg5,7Ac2-glycans of data presented in (b) (Friedman test with uncorrected Dunn’s test; ns p = 0.4631, * p = 0.0159, *** p = 0.0002, and **** p < 0.0001). Full article ">Scheme 1
Chemoenzymatic synthesis of α2–6-linked Leg5,7Ac2-glycosides (25–31) via OP3E produced α2–6-linked Leg5,7diN3-glycosides (12–18). Full article ">Scheme 2
Chemoenzymatic synthesis of α2–3-linked Leg5,7Ac2-glycosides (32–37) via OP3E produced α2–3-linked Leg5,7diN3-glycosides (19–24). Full article ">

12 pages, 5407 KiB

Open AccessArticle

Waste Point Identification of Frying Oil Based on Gas Chromatography–Ion Mobility Spectrometry (GC-IMS)

by Lin Ye, Lijun Song, Li Zhang and Ruiguo Cui

Molecules 2024, 29(16), 3979; https://doi.org/10.3390/molecules29163979 - 22 Aug 2024

Viewed by 803

Abstract

This study described the quality detection and rapid identification of frying oil waste points based on gas chromatography–ion mobility spectrometry (GC-IMS). A total of 48 volatile substances were identified, among which the levels of 11 components, including 2-pentylfuran, 2-butylfuran, and 2-hexanone, increased with [...] Read more.

This study described the quality detection and rapid identification of frying oil waste points based on gas chromatography–ion mobility spectrometry (GC-IMS). A total of 48 volatile substances were identified, among which the levels of 11 components, including 2-pentylfuran, 2-butylfuran, and 2-hexanone, increased with prolonged frying time after 40 h in cottonseed oil. Conversely, the levels of hexanal, heptanal, and E,E-2,4-heptadienal decreased as frying time extended. Correlation analysis revealed a significant association between volatile substances of the oil and acid value (p < 0.05) and polar components with volatile substances (p < 0.05). Furthermore, significant differences in the types and contents of flavor substances were observed in cottonseed oil at different frying times (including before and after reaching the discard point) (p < 0.05). Subsequently, principal component analysis (PCA) results clearly showed that the cottonseed oil samples at different frying times were well distinguished by the volatile compounds; moreover, discriminant model analysis indicated a model accuracy rate of 100%. These results showed the potential of GC-IMS-based approaches in discriminating the waste points of frying oil. Full article

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The abbreviations MS0, MS8, MS16, MS24, MS32, MS40, MS48, MS56, MS64, MS72, and MS80 represent 0, 8, 16, 24, 32, 40, 48, 56, 64, 72, and 80 h. (A) Three-dimensional topographic plots of volatile compounds in cottonseed oil during frying. (B) Two-dimensional topographic plots of volatile compounds during frying in cottonseed oil (top view). (C) Comparison and difference spectrum of volatile substances in cottonseed oil during frying. (D) Fingerprint of volatile compounds in cottonseed oil during frying. Full article ">Figure 1 Cont.
The abbreviations MS0, MS8, MS16, MS24, MS32, MS40, MS48, MS56, MS64, MS72, and MS80 represent 0, 8, 16, 24, 32, 40, 48, 56, 64, 72, and 80 h. (A) Three-dimensional topographic plots of volatile compounds in cottonseed oil during frying. (B) Two-dimensional topographic plots of volatile compounds during frying in cottonseed oil (top view). (C) Comparison and difference spectrum of volatile substances in cottonseed oil during frying. (D) Fingerprint of volatile compounds in cottonseed oil during frying. Full article ">Figure 2
PCA of volatile compounds in cottonseed oil during frying. Full article ">Figure 3
Support vector machine model analysis diagram of naan before and after being discarded in the process of frying in cottonseed oil; class1 and class2 present naan before and after being discarded in the process of frying in cottonseed oil. Full article ">

31 pages, 3353 KiB

Open AccessReview

Chemical-Assisted CO₂ Water-Alternating-Gas Injection for Enhanced Sweep Efficiency in CO₂-EOR

by Pengwei Fang, Qun Zhang, Can Zhou, Zhengming Yang, Hongwei Yu, Meng Du, Xinliang Chen, Yuxuan Song, Sicai Wang, Yuan Gao, Zhuoying Dou and Meiwen Cao

Molecules 2024, 29(16), 3978; https://doi.org/10.3390/molecules29163978 - 22 Aug 2024

Cited by 1 | Viewed by 2722

Abstract

CO₂-enhanced oil recovery (CO₂-EOR) is a crucial method for CO₂ utilization and sequestration, representing an important zero-carbon or even negative-carbon emission reduction technology. However, the low viscosity of CO₂ and reservoir heterogeneity often result in early gas [...] Read more.

CO₂-enhanced oil recovery (CO₂-EOR) is a crucial method for CO₂ utilization and sequestration, representing an important zero-carbon or even negative-carbon emission reduction technology. However, the low viscosity of CO₂ and reservoir heterogeneity often result in early gas breakthrough, significantly reducing CO₂ utilization and sequestration efficiency. A water-alternating-gas (WAG) injection is a technique for mitigating gas breakthrough and viscous fingering in CO₂-EOR. However, it encounters challenges related to insufficient mobility control in highly heterogeneous and fractured reservoirs, resulting in gas channeling and low sweep efficiency. Despite the extensive application and research of a WAG injection in oil and gas reservoirs, the most recent comprehensive review dates back to 2018, which focuses on the mechanisms of EOR using conventional WAG. Herein, we give an updated and comprehensive review to incorporate the latest advancements in CO₂-WAG flooding techniques for enhanced sweep efficiency, which includes the theory, applications, fluid displacement mechanisms, and control strategies of a CO₂-WAG injection. It addresses common challenges, operational issues, and remedial measures in WAG projects by covering studies from experiments, simulations, and pore-scale modeling. This review aims to provide guidance and serve as a reference for the application and research advancement of CO₂-EOR techniques in heterogeneous and fractured reservoirs. Full article

(This article belongs to the Special Issue Advanced Chemical Approaches and Technologies in Water Treatment)

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Schematic of gas channeling due to differences in mobility ratio under various injection methods, (a) continuous gas injection, (b) conventional WAG injection, and (c) chemical-assisted WAG. Modified after Afzali S [<a href="#B17-molecules-29-03978" class="html-bibr">17</a>], Copyright 2018, with permission from Elsevier. Full article ">Figure 2
Schematic of WAG sweep efficiency influenced by reservoir properties and gravity segregation. Full article ">Figure 3
(a) Illustration of the wetting phase (red) invading pores saturated with the non-wetting phase (blue); (b) Schematic of oil phase entrapment (red) caused by water and gas bypassing at different pore volumes (PV) of injection (blue indicates the water or gas phase) [<a href="#B42-molecules-29-03978" class="html-bibr">42</a>]. (Copyright 2022, with permission from Elsevier). Full article ">Figure 4
Schematic diagram of SWAG Injection. Full article ">Figure 5
Schematic diagram of FAWAG injection technology. Full article ">Figure 6
(a) CO2-responsive functional groups; (b) CO2-responsive gel mechanism (modified after Ding Y et al. [<a href="#B125-molecules-29-03978" class="html-bibr">125</a>]). Full article ">Figure 7
Schematic diagram of the multi-stage GWAG technology. Full article ">Figure 8
Schematic diagram of NWAG injection technology. Full article ">

13 pages, 3568 KiB

Open AccessArticle

Study on the Rapid Limit Test for Six Sulfonamide Residues in Food Based on the TLC-SERS Method

by Yukun Ma, Min Zhang, Li Li, Jicheng Liu, Feng Xu, Yuanrui Wang, Bo Song, Tao Xu, Yue Hong and Honglian Zhang

Molecules 2024, 29(16), 3977; https://doi.org/10.3390/molecules29163977 - 22 Aug 2024

Viewed by 891

Abstract

Sulfonamides are not only widely applied in clinics but also highly valued in animal husbandry. Recently, it has become common for sulfonamide residues to exceed the standard limits in food, which can affect human health. Current regulations limit these residues. Therefore, we constructed [...] Read more.

Sulfonamides are not only widely applied in clinics but also highly valued in animal husbandry. Recently, it has become common for sulfonamide residues to exceed the standard limits in food, which can affect human health. Current regulations limit these residues. Therefore, we constructed a new limit test method to rapidly determine the levels of sulfonamide residues. Six sulfonamides were detected using the latest method called TLC-SERS, namely, sulfamethasone (A), sulfamethazine (B), sulfadoxine (C), sulfamethoxydiazine (D), sulfamethoxazole (E), and sulfathiazole (F). The optimal conditions for SERS detection were investigated for these six drugs, and the separation effects of different TLC spreaders on them were compared. Then, we successfully established a separation system using dichloromethane–methanol–ammonia in a ratio of 5:1:0.25 (v/v/v), which provided good separation effects on the six drugs. The residues were preliminarily separated via TLC. A silver sol solution was added to the spot on the silica gel G plate at the corresponding specific shift values, and SERS detection was performed. The sample solution was placed on the spot under a 532 nm laser, and the SERS spectrum was collected and analyzed for the six sulfonamides. The results showed obvious variations in the SERS spectrum among the six sulfonamides, with the LODs being 12.5, 6.4, 6.3, 7.1, 18.8, and 6.2 ng/mL from A to F, respectively, and an RSD of <3.0%. Within 48 h, the SERS signal for each sulfonamide drug was kept stable, with an RSD of <3.0%. The detection results of 20 samples using the TLC-SERS method were consistent with those obtained by UPLC-MS/MS. The established TLC-SERS method is simple and fast, providing a useful reference for the rapid detection of residue limits in food. Full article

(This article belongs to the Special Issue Advanced Analytical Tools for Characterization and Quality Control of Food, Drugs, and Natural Active Ingredients, 2nd Edition)

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11 pages, 5644 KiB

Open AccessArticle

The Anti-Melanogenic Effects of Ganodermanontriol from the Medicinal Mushroom Ganoderma lucidum through the Regulation of the CREB and MAPK Signaling Pathways in B16F10 Cells

by Che-Hwon Park, Youn-Lee Oh, Ju-Hyeon Shin and Young-Jin Park

Molecules 2024, 29(16), 3976; https://doi.org/10.3390/molecules29163976 - 22 Aug 2024

Viewed by 1029

Abstract

Ganoderma lucidum, a member of the Basidiomycetes family, is attracting attention for its medicinal potential due to its biological activity and the presence of numerous bioactive compounds. Although it is known that extracts of this mushroom inhibit melanin production, there are few [...] Read more.

Ganoderma lucidum, a member of the Basidiomycetes family, is attracting attention for its medicinal potential due to its biological activity and the presence of numerous bioactive compounds. Although it is known that extracts of this mushroom inhibit melanin production, there are few reports on a single substance associated with this effect. In this study, we identified ganodermanontriol (GT), a novel compound from G. lucidum, that effectively inhibited melanin biosynthesis in B16F10 cells. GT inhibits melanin production by suppressing the expression of cellular tyrosinase proteins and microphthalmia-related transcription factor (MITF). Furthermore, GT affects the phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) and mitogen-activated protein kinase (MAPK) signaling molecules, which are involved in melanogenesis in B16F10 cells. Finally, the biosynthesis of GT and other substances by G. lucidum was evaluated using HPLC analysis. Thus, this study revealed the mechanism by which GT in G. lucidum inhibits melanin production in B16F10 cells, and these findings will contribute to promoting the potential use of this mushroom in the future. Full article

(This article belongs to the Special Issue Extraction, Characterization, and Potential Applications of Bioactive Molecules from Natural Sources Ⅲ)

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Chemical structure (a), cytotoxicity (b), and melanin synthesis inhibitory activity (c) of ganodermanontriol (GT). The data were analyzed using one-way ANOVA followed by Tukey’s test. *** p < 0.001 vs. B16F10 cells without sample treatment. Arb, arbutin (0.5 mM). Full article ">Figure 2
Effects of ganodermanontriol (GT) on expression of cellular tyrosinase and microphthalmia-associated transcription factor (MITF) proteins in B16F10 cells. Relative protein expression levels of tyrosinase (a), tyrosinase-related protein 1 (TRP-1) (b), and MITF protein (c). Relative protein levels were quantified using Western blot analysis (d). The data were analyzed using one-way ANOVA followed by Tukey’s test. * p < 0.05, ** p < 0.01, and *** p < 0.001 vs. B16F10 cells without sample treatment. Arb, arbutin (0.5 mM). Full article ">Figure 3
Effects of ganodermanontriol (GT) on phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) in B16F10 cells (a). Relative phosphorylation levels were quantified using Western blot analysis (b). The data were analyzed using one-way ANOVA followed by Tukey’s test. * p < 0.05, ** p < 0.01, and *** p < 0.001 vs. B16F10 cells without sample treatment. Arb, arbutin (0.5 mM). Full article ">Figure 4
Effects of ganodermanontriol (GT) on phosphorylation of extracellular signal-regulated kinases (ERKs) (a), c-Jun N-terminal kinases (JNKs) (b), and p38 (c) proteins in B16F10 cells. Relative phosphorylation levels were quantified using Western blot analysis (d). The data were analyzed using one-way ANOVA followed by Tukey’s test. * p < 0.05, ** p < 0.01, and *** p < 0.001 vs. B16F10 cells without sample treatment. Arb, arbutin (0.5 mM). Full article ">Figure 5
HPLC profiles (a) and HPLC-PDA chromatograms (b) of ganodermanontriol (GT) and G. lucidum extract. Rt, retention time. Arrows indicate GT-specific peaks. Full article ">Figure 6
HPLC chromatograms (a) and ESI-MS spectra (b) of ganodermanontriol (GT) and GT from G. lucidum. Rt, retention time. Arrows indicate GT-specific peaks. Full article ">Figure 7
Isolation procedure of ganodermanontriol from Ganoderma lucidum. The purification was started with the fruit body of G. lucidum. Each step is indicated by one arrow. Full article ">

13 pages, 4371 KiB

Open AccessArticle

Investigating the Discoloration of Leaves of Dioscorea polystachya Using Developed Atomic Absorption Spectrometry Methods for Manganese and Molybdenum

by David Krüger, Alexander Weng and Daniel Baecker

Molecules 2024, 29(16), 3975; https://doi.org/10.3390/molecules29163975 - 22 Aug 2024

Viewed by 927

Abstract

The Chinese yam (Dioscorea polystachya, DP) is promising for the food and pharmaceutical industries due to its nutritional value and pharmaceutical potential. Its proper cultivation is therefore of interest. An insufficient supply of minerals necessary for plant growth can be manifested [...] Read more.

The Chinese yam (Dioscorea polystachya, DP) is promising for the food and pharmaceutical industries due to its nutritional value and pharmaceutical potential. Its proper cultivation is therefore of interest. An insufficient supply of minerals necessary for plant growth can be manifested by discoloration of the leaves. In our earlier study, magnesium deficiency was excluded as a cause. As a follow-up, this work focused on manganese and molybdenum. To quantify both minerals in leaf extracts of DP, analytical methods based on atomic absorption spectrometry (AAS) using the graphite furnace sub-technique were devised. The development revealed that the quantification of manganese works best without using any of the investigated modifiers. The optimized pyrolysis and atomization temperatures were 1300 °C and 1800 °C, respectively. For the analysis of molybdenum, calcium proved to be advantageous as a modifier. The optimum temperatures were 1900 °C and 2800 °C, respectively. Both methods showed satisfactory linearity for analysis. Thus, they were applied to quantify extracts from normal and discolored leaves of DP concerning the two minerals. It was found that discolored leaves had higher manganese levels and a lower molybdenum content. With these results, a potential explanation for the discoloration could be found. Full article

(This article belongs to the Special Issue Application of Spectroscopy for Drugs)

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Graphical abstract

Graphical abstract
Full article ">Figure 1
Wavelength-resolved absorption spectrum (blue) of manganese (Mn, (left)) and molybdenum (Mo, (right)). The red line indicates the wavelength of manganese (λ = 279.4817 nm) and molybdenum (λ = 313.2594 nm), respectively. The measurement of the integrated signal over three pixels is indicated by the orange bar. The spectra shown were recorded during the quantification of the calibration standards of 6 μg L−1 for manganese and 100 μg L−1 for molybdenum. Full article ">Figure 2
Pyrolysis (left) and atomization (right) curves for the assessment of manganese (λ = 279.4817 nm). A volume of 10 µL of diluted leaf extract was injected into the graphite furnace for each measurement. The curves represent the cases of using no additive (⬤) or adding the chemical modifiers palladium (⬤), palladium and tartaric acid (⬤), palladium and ascorbic acid (⬤), as well as calcium (⬤). The data represent the mean of four different extracts with three injections each. The error bars were omitted to allow better readability. Full article ">Figure 3
Pyrolysis (left) and atomization (right) curves for the assessment of molybdenum (λ = 313.2594 nm). A volume of 10 µL of diluted leaf extract was injected into the graphite furnace for each measurement. The curves represent the cases of using no additive (⬤) or adding the chemical modifiers palladium (⬤), palladium and tartaric acid (⬤), palladium and ascorbic acid (⬤), as well as calcium (⬤). The data represent the mean of four different extracts with two injections each. The error bars were omitted to allow better readability. Full article ">Figure 4
Exemplary illustration of a normal-colored leaf (left) and a discolored leaf (right) of Dioscorea polystachya. In addition to the yellowing of the deficient leaves, these also exhibit brownish areas. Full article ">

18 pages, 6201 KiB

Open AccessReview

Advances in Aptamer-Based Biosensors for the Detection of Foodborne Mycotoxins

by Yangyang Li, Dan Zhang, Xiaoyuan Zeng, Cheng Liu, Yan Wu and Cuicui Fu

Molecules 2024, 29(16), 3974; https://doi.org/10.3390/molecules29163974 - 22 Aug 2024

Cited by 1 | Viewed by 1323

Abstract

Foodborne mycotoxins (FBMTs) are toxins produced by food itself or during processing and transportation that pose an enormous threat to public health security. However, traditional instrumental and chemical methods for detecting toxins have shortcomings, such as high operational difficulty, time consumption, and high [...] Read more.

Foodborne mycotoxins (FBMTs) are toxins produced by food itself or during processing and transportation that pose an enormous threat to public health security. However, traditional instrumental and chemical methods for detecting toxins have shortcomings, such as high operational difficulty, time consumption, and high cost, that limit their large-scale applications. In recent years, aptamer-based biosensors have become a new tool for food safety risk assessment and monitoring due to their high affinity, good specificity, and fast response. In this review, we focus on the progress of single-mode and dual-mode aptasensors in basic research and device applications over recent years. Furthermore, we also point out some problems in the current detection strategies, with the aim of stimulating future toxin detection systems for a transition toward ease of operation and rapid detection. Full article

(This article belongs to the Special Issue Raman Spectroscopy for Biological Applications)

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Full article ">Figure 1
(a) AuNP-based CM detection assay format; (b) Sensing mechanism toward STX and TTX based on NMOFs-aptasensor; (c) Sensing process in microtubule (A) and on electrode surface (B); (d) Preparation for SH-cDNA-ADANRs (A) and NH2-apt-CS-Fe3O4 (B), and SERS detection schematic (C). Full article ">Figure 2
(a) Unlabeled CM-FL aptasensor for detection of OTA; (b) The portable CM-FL aptamer sensor device (A) and the detection principle of OTA (B); (c) Fluorometric and CM aptasensor for detection of histamine; (d) CPNs(IV)-based aptasensor for malathion detection. Full article ">Figure 3
(a) Dual-signal output mechanism of SERS-FL aptasensor for determination of AFB1; (b) Working principle of the on-off-type aptasensor; (c) The “turn on” UCL-SERS aptasensor for detection of OTA; (d) Sensing mechanism of trimer-based high-throughput sensors. Full article ">Figure 4
(a) Working principle of the dual-ratiometric aptasensor based on EC and PEC assays; (b) The detection of AFB1 in EC mode and PEC mode; (c) Priority binding order of the four aptamers with PAT; (d) Mechanism diagram of PEC/visualization dual-mode detection of DON. Full article ">Figure 5
(a) ECL-EC aptasensor based on PoPD/Ru-Au for AOH detection; (b) Ag@Cu2O-engineered EC-SERS aptasensor for TTX detection, adapted with permission from Ref. [<a href="#B113-molecules-29-03974" class="html-bibr">113</a>]. 2024, Elsevier; (c) The detection of T-2 by the FL-FP split aptasensor; (d) Detection mechanism of three subtypes of AF. Full article ">Figure 6
(a) Signal conversion strategy of the portable nanopore biosensor for OTA detection; (b) Portable CL-optical fiber aptasensor for analysis of multiple mycotoxins; (c) Structure and sensing principle of LFAA for simultaneous detection of multiple targets; (d) Scheme of modification (A), cleaning (B) and (C) sensing principle of EC-CM PAD. Full article ">Scheme 1
Different detection modes of aptamer-based biosensors. Full article ">

24 pages, 7613 KiB

Open AccessReview

The Application of Hydrogen Sulfide Fluorescent Probe in Food Preservation, Detection and Evaluation

by Sitong Chen, Xiongjie Zhao and Liyi Zhou

Molecules 2024, 29(16), 3973; https://doi.org/10.3390/molecules29163973 - 22 Aug 2024

Viewed by 1129

Abstract

This work primarily reviewed the response mechanism of fluorescent probes for H₂S detection in foodstuffs in recent years, as well as the methodologies employed for detecting foodstuffs. Firstly, the significance of studying H₂S gas as an important signaling molecule [...] Read more.

This work primarily reviewed the response mechanism of fluorescent probes for H₂S detection in foodstuffs in recent years, as well as the methodologies employed for detecting foodstuffs. Firstly, the significance of studying H₂S gas as an important signaling molecule is introduced. Subsequently, a review of the response mechanism of the scientific community on how to detect H₂S in foodstuffs samples by fluorescent probe technology is carried out. Secondly, the methods commonly used for detecting foodstuffs samples are discussed, including the test strip method and the spiking recovery methods. Nevertheless, despite the significant advancements in this field, there remain some research gaps. Finally, the article identifies the remaining issues that require further attention in current research and proposes avenues for future investigation. More importantly, this work identifies the current limitations of research in this field and proposes future applications of fluorescent probes for H₂S in assessing food freshness and determining food spoilage. Therefore, this review will provide robust technical support for the protection of consumer health and the advancement of the sustainable development of the food industry and also put forward some new ideas and suggestions for future research. Full article

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12 pages, 1892 KiB

Open AccessArticle

Comparison between Electropolymers of 3,5-Dihydroxybenzoic Acid and 2′,6′-Dihydroxyacetophenone in Dimethyl Sulfoxide and Their Analytical Performance towards Selected Analytes with the Role of the Washing Liquid

by László Kiss, Heng Li, Hui Yan and Sándor Kunsági-Máté

Molecules 2024, 29(16), 3972; https://doi.org/10.3390/molecules29163972 - 22 Aug 2024

Cited by 1 | Viewed by 671

Abstract

In the first part of this study, the electrochemical polymerization of two compounds, 3,5-dihydroxybenzoic acid and 2′,6′-dihydroxyacetophenone, was compared in dimethyl sulfoxide solvent on platinum and glassy carbon electrodes. The voltammograms obtained showed remarkable differences between the two monomers and between the two [...] Read more.

In the first part of this study, the electrochemical polymerization of two compounds, 3,5-dihydroxybenzoic acid and 2′,6′-dihydroxyacetophenone, was compared in dimethyl sulfoxide solvent on platinum and glassy carbon electrodes. The voltammograms obtained showed remarkable differences between the two monomers and between the two electrode materials. The acetophenone derivative formed electropolymer remnants at the electrodes, while in the case of the benzoic acid derivative, practically no passivation occurred, and the scanning electron microscopic results reinforced this. A few stackings adsorbed only after electropolymerization from a highly concentrated solution of dihydroxybenzoic acid. As a modifying layer on the platinum and glassy carbon electrodes, the prepared films from 2′,6′-dihydroxyacetophenone were tested for tributylamine in acetonitrile and in an aqueous solution of a redox-active compound, hydroquinone, during the stirring of the solution. More stable amperometric current signals could be reached with modified platinum than with glassy carbon, and the significant influence of the organic washing liquid after deposition was established via the study of noise level. In this respect, acetone was the best choice. The amperometric signals with the modified platinum obtained upon the addition of aliquots of the stock solution resulted in a 3.29 μM detection limit. Full article

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Cyclic voltammograms for 3,5−dihydroxybenzoic acid (a) and 2′,6′−dihydroxyacetophenone (b) in dimethyl sulfoxide in their 100 mM solutions on a platinum electrode; (c) the same for 3,5−dihydroxybenzoic acid and (d) for 2′,6′−dihydroxybenzoic acid on a glassy carbon electrode (scan rate 0.1 V/s, supporting electrolyte 100 mM TBAP; the inset graphs show curves recorded in 25 mM solutions and the direction of arrows on curves indicate the direction of the change in voltametric peak heights). Full article ">Figure 2
Scanning electron micrographs of electrodeposited films of 3,5-dihydroxybenzoic acid (35 Bz COOH, (a–d) and 2′,6′-dihydroxyacetophenone (26 acf, (e–h)) from dimethyl sulfoxide of different concentrations. The second numbers in labels reflect the monomer concentrations: (a–d) or (e–h) related to the 25 mM, 50 mM, 75 mM and 100 mM monomer concentrations, respectively. Full article ">Figure 2 Cont.
Scanning electron micrographs of electrodeposited films of 3,5-dihydroxybenzoic acid (35 Bz COOH, (a–d) and 2′,6′-dihydroxyacetophenone (26 acf, (e–h)) from dimethyl sulfoxide of different concentrations. The second numbers in labels reflect the monomer concentrations: (a–d) or (e–h) related to the 25 mM, 50 mM, 75 mM and 100 mM monomer concentrations, respectively. Full article ">Figure 3
The dependence of the first peak currents on the concentration of 3,5-dihydroxybenzoic acid by varying the acetonitrile (ACN) content in v/v %. Full article ">Figure 4
The dependence of peak currents (a) and peak potentials (b) on the immersion time of poly(2′,6′-dihydroxyacetophenone) in 10 mM acetonitrile solution of tributylamine containing 20 mM TBAP. Full article ">Figure 5
Chronoamperometric curves of glassy carbon and platinum electrodes modified with poly(2′,6′-dihydroxyacetophenone) after washing with acetone with response to stirring at 700 rpm in 5 mM solution of hydroquinone with pH set to 7 with 0.05 mol/L phosphate buffer. Full article ">Figure 6
Amperometric curve for hydroquinone during stirring at 700 rpm by sequential addition of stock solution for concentrations 0, 100, 200, 300, 400, and 500 mM with a poly(2′,6′-dihydroxyacetophenone)-modified platinum electrode (supporting electrolyte 0.05 M pH = 7 phosphate buffer, constant potential 0.5 V). Full article ">

16 pages, 3065 KiB

Open AccessArticle

Utilizing Morphological and Physiological Parameters of Lemna minor for Assessing Tetracyclines’ Removal

by Łukasz Sikorski, Agnieszka Bęś, Kazimierz Warmiński, Wojciech Truszkowski and Przemysław Kowal

Molecules 2024, 29(16), 3971; https://doi.org/10.3390/molecules29163971 - 22 Aug 2024

Viewed by 832

Abstract

Antibiotics with significant environmental toxicity, e.g., tetracyclines (TCs), are often used in large quantities worldwide, with 50–80% of the applied dose ending up in the environment. This study aimed to investigate the effects of exposure to tetracycline hydrochloride (TC) and minocycline hydrochloride (MIN) [...] Read more.

Antibiotics with significant environmental toxicity, e.g., tetracyclines (TCs), are often used in large quantities worldwide, with 50–80% of the applied dose ending up in the environment. This study aimed to investigate the effects of exposure to tetracycline hydrochloride (TC) and minocycline hydrochloride (MIN) on L. minor. Our research evaluated the phytotoxicity of the TCs by analyzing plant growth and biomass and evaluating assimilation pigment levels and fluorescence. The research was extended with the ability potential of duckweed as a tool for removing TCs from water/wastewater. The results demonstrated that both TCs influenced Ir, Iy, biomass, and photosynthetic efficiency. The uptake of TC and MIN by duckweed was proportional to the concentration in the growth medium. The TC was absorbed more readily, reaching up to 8.09 mg × g⁻¹ of dry weight (DW) at the highest concentration (19.2 mg × L⁻¹), while MIN reached 6.01 mg × g⁻¹ of DW. As indicated, the consequences of the influence of TC on plants were slightly smaller, in comparison to MIN, while the plants could biosorb this drug, even at the lowest tested concentration. This study has shown that using plants for drug biosorption can be an effective standalone or complementary method for water and wastewater treatment. Full article

(This article belongs to the Special Issue Wastewater Treatments Based on Adsorption, Catalysis, Biodegradation, and beyond II)

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Percent inhibition of growth rate (Ir) (A), percent reduction in yield (Iy) (B) of common duckweed (L. minor) exposed to different concentrations (0–19.2 mg × L−1) of tetracycline hydrochloride (TC) and minocycline hydrochloride (MIN). Data points represent the mean ± SD, n = 6. * Values differ significantly from the control at p < 0.01. Full article ">Figure 2
Fresh mass (FM) (A) of 100 fronds and dry matter content (DM) (B) of common duckweed (L. minor) exposed to different concentrations (0–19.2 mg × L−1) of tetracycline hydrochloride (TC) and minocycline hydrochloride (MIN). Data points represent the mean ± SD, n = 6. * Values differ significantly from the control at p < 0.01. Full article ">Figure 3
Content of chlorophyll a (Chl a) (A), chlorophyll b (Chl b) (B), total carotenoid content (TCC) (C), and the phaeophytinization quotient (PQ) (D) of common duckweed (L. minor) exposed to different concentrations (0–19.2 mg × L−1) of tetracycline hydrochloride (TC) and minocycline hydrochloride (MIN). Data points represent the mean ± SD, n = 6. * Values differ significantly from the control at p < 0.01. Full article ">Figure 4
Maximum quantum efficiency (Fv/Fm) of common duckweed (L. minor) exposed to different concentrations (0–19.2 mg × L−1) of tetracycline hydrochloride (TC) and minocycline hydrochloride (MIN). Data points represent the mean ± SD, n = 6. * Values differ significantly from the control at p < 0.01. Full article ">Figure 5
Antibiotic biosorption (Bs) by common duckweed (L. minor) exposed to different concentrations (0–19.2 mg × L−1) of tetracycline hydrochloride (TC) and minocycline hydrochloride (MIN). Data points represent the mean ± SD, n = 6. * Values differ significantly from the control at p < 0.01. Full article ">

17 pages, 3890 KiB

Open AccessArticle

Visible-Light-Induced Diselenide-Crosslinked Polymeric Micelles for ROS-Triggered Drug Delivery

by Xinfeng Cheng, Huixian Li, Xiaomeng Sun, Tianxu Xu, Zhenzhen Guo, Xianchao Du, Shuai Li, Xuyang Li, Xiaojing Xing and Dongfang Qiu

Molecules 2024, 29(16), 3970; https://doi.org/10.3390/molecules29163970 - 22 Aug 2024

Viewed by 1177

Abstract

To synthesize an effective and versatile nano-platform serving as a promising carrier for controlled drug delivery, visible-light-induced diselenide-crosslinked polyurethane micelles were designed and prepared for ROS-triggered on-demand doxorubicin (DOX) release. A rationally designed amphiphilic block copolymer, poly(ethylene glycol)-b-poly(diselenolane diol-co-isophorone diisocyanate)-b [...] Read more.

To synthesize an effective and versatile nano-platform serving as a promising carrier for controlled drug delivery, visible-light-induced diselenide-crosslinked polyurethane micelles were designed and prepared for ROS-triggered on-demand doxorubicin (DOX) release. A rationally designed amphiphilic block copolymer, poly(ethylene glycol)-b-poly(diselenolane diol-co-isophorone diisocyanate)-b-poly(ethylene glycol) (PEG-b-PUSe-b-PEG), which incorporates dangling diselenolane groups within the hydrophobic PU segments, was initially synthesized through the polycondensation reaction. In aqueous media, this type of amphiphilic block copolymer can self-assemble into micellar aggregates and encapsulate DOX within the micellar core, forming DOX-loaded micelles that are subsequently in situ core-crosslinked by diselenides via a visible-light-triggered metathesis reaction of Se-Se bonds. Compared with the non-crosslinked micelles (NCLMs), the as-prepared diselenide-crosslinked micelles (CLMs) exhibited a smaller particle size and improved colloidal stability. In vitro release studies have demonstrated suppressed drug release behavior for CLMs in physiological conditions, as compared to the NCLMs, whereas a burst release of DOX occurred upon exposure to an oxidation environment. Moreover, MTT assay results have revealed that the crosslinked polyurethane micelles displayed no significant cytotoxicity towards HeLa cells. Cellular uptake analyses have suggested the effective internalization of DOX-loaded crosslinked micelles and DOX release within cancer cells. These findings suggest that this kind of ROS-triggered reversibly crosslinked polyurethane micelles hold significant potential as a ROS-responsive drug delivery system. Full article

(This article belongs to the Special Issue Molecular Approaches to Drug Discovery and Development)

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12 pages, 4152 KiB

Open AccessArticle

Exploring Molecular Heteroencoders with Latent Space Arithmetic: Atomic Descriptors and Molecular Operators

by Xinyue Gao, Natalia Baimacheva and Joao Aires-de-Sousa

Molecules 2024, 29(16), 3969; https://doi.org/10.3390/molecules29163969 - 22 Aug 2024

Viewed by 1024

Abstract

A variational heteroencoder based on recurrent neural networks, trained with SMILES linear notations of molecular structures, was used to derive the following atomic descriptors: delta latent space vectors (DLSVs) obtained from the original SMILES of the whole molecule and the SMILES of the [...] Read more.

A variational heteroencoder based on recurrent neural networks, trained with SMILES linear notations of molecular structures, was used to derive the following atomic descriptors: delta latent space vectors (DLSVs) obtained from the original SMILES of the whole molecule and the SMILES of the same molecule with the target atom replaced. Different replacements were explored, namely, changing the atomic element, replacement with a character of the model vocabulary not used in the training set, or the removal of the target atom from the SMILES. Unsupervised mapping of the DLSV descriptors with t-distributed stochastic neighbor embedding (t-SNE) revealed a remarkable clustering according to the atomic element, hybridization, atomic type, and aromaticity. Atomic DLSV descriptors were used to train machine learning (ML) models to predict ¹⁹F NMR chemical shifts. An R² of up to 0.89 and mean absolute errors of up to 5.5 ppm were obtained for an independent test set of 1046 molecules with random forests or a gradient-boosting regressor. Intermediate representations from a Transformer model yielded comparable results. Furthermore, DLSVs were applied as molecular operators in the latent space: the DLSV of a halogenation (H→F substitution) was summed to the LSVs of 4135 new molecules with no fluorine atom and decoded into SMILES, yielding 99% of valid SMILES, with 75% of the SMILES incorporating fluorine and 56% of the structures incorporating fluorine with no other structural change. Full article

(This article belongs to the Special Issue QSAR and QSPR: Recent Developments and Applications, 4th Edition)

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16 pages, 262 KiB

Open AccessReview

The Chemical Residues in Secondary Beekeeping Products of Environmental Origin

by Joanna Wojtacka

Molecules 2024, 29(16), 3968; https://doi.org/10.3390/molecules29163968 - 22 Aug 2024

Viewed by 1022

Abstract

Natural products of bee origin, despite their complex composition and difficulties in standardization, have been of high interest among scientists representing various disciplines from basic sciences to industrial and practical implementation. As long as their use is monitored and they do not impact [...] Read more.

Natural products of bee origin, despite their complex composition and difficulties in standardization, have been of high interest among scientists representing various disciplines from basic sciences to industrial and practical implementation. As long as their use is monitored and they do not impact human health, they can be considered valuable sources of many chemical compounds and are potentially useful in medicine, food processing, nutrition, etc. However, apart from honey, the general turnover of bee products lacks precise and detailed legal requirements ensuring their quality. The different residues in these products constitute a problem, which has been reported in numerous studies. All products derived from beekeeping are made by bees, but they are also influenced by the environment. Such a dual pathway requires detailed surveillance of hazards stemming from outside and inside the apiary. This should be ensured via harmonized requirements arising from the binding legal acts, especially in international and intercontinental trade zones. Full article

(This article belongs to the Special Issue Phytochemistry, Human Health and Molecular Mechanisms)

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14 pages, 5927 KiB

Open AccessFeature PaperArticle

A Strategic Synthesis of Orange Waste-Derived Porous Carbon via a Freeze-Drying Method: Morphological Characterization and Cytocompatibility Evaluation

by Angela S. Kaloudi, Panagiota Zygouri, Konstantinos Spyrou, Antrea-Maria Athinodorou, Eirini Papanikolaou, Mohammed Subrati, Dimitrios Moschovas, K. K. R. Datta, Zili Sideratou, Apostolos Avgeropoulos, Yannis V. Simos, Konstantinos I. Tsamis, Dimitrios Peschos, Ioannis V. Yentekakis and Dimitrios P. Gournis

Molecules 2024, 29(16), 3967; https://doi.org/10.3390/molecules29163967 - 22 Aug 2024

Viewed by 1341

Abstract

Porous carbon materials from food waste have gained growing interest worldwide for multiple applications due to their natural abundance and the sustainability of the raw materials and the cost-effective synthetic processing. Herein, orange waste-derived porous carbon (OWPC) was developed through a freeze-drying method [...] Read more.

Porous carbon materials from food waste have gained growing interest worldwide for multiple applications due to their natural abundance and the sustainability of the raw materials and the cost-effective synthetic processing. Herein, orange waste-derived porous carbon (OWPC) was developed through a freeze-drying method to prevent the demolition of the original biomass structure and then was pyrolyzed to create a large number of micro, meso and macro pores. The novelty of this work lies in the fact of using the macro-channels of the orange waste in order to create a macroporous network via the freeze-drying method which remains after the pyrolysis steps and creates space for the development of different types of porous in the micro and meso scale in a controlled way. The results showed the successful preparation of a porous carbon material with a high specific surface area of 644 m² g⁻¹ without any physical or chemical activation. The material’s cytocompatibility was also investigated against a fibroblast cell line (NIH/3T3 cells). OWPC triggered a mild intracellular reactive oxygen species production without initiating apoptosis or severely affecting cell proliferation and survival. The combination of their physicochemical characteristics and high cytocompatibility renders them promising materials for further use in biomedical and pharmaceutical applications. Full article

(This article belongs to the Collection Porous Materials)

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14 pages, 5137 KiB

Open AccessCommunication

Nickel–Molybdenum-Based Three-Dimensional Nanoarrays for Oxygen Evolution Reaction in Water Splitting

by Zhi Lu, Shilin Li, Yuxin Wang, Jiefeng Wang, Yifan Guo, Jiaqi Ding, Kun Tang, Yingzi Ren, Long You, Hongbo Meng and Guangxin Wang

Molecules 2024, 29(16), 3966; https://doi.org/10.3390/molecules29163966 - 22 Aug 2024

Viewed by 804

Abstract

Water splitting is an important approach to hydrogen production. But the efficiency of the process is always controlled by the oxygen evolution reaction process. In this study, a three-dimensional nickel–molybdenum binary nanoarray microstructure electrocatalyst is successfully synthesized. It is grown uniformly on Ni [...] Read more.

Water splitting is an important approach to hydrogen production. But the efficiency of the process is always controlled by the oxygen evolution reaction process. In this study, a three-dimensional nickel–molybdenum binary nanoarray microstructure electrocatalyst is successfully synthesized. It is grown uniformly on Ni foam using a hydrothermal method. Attributed to their unique nanostructure and controllable nature, the Ni-Mo-based nanoarray samples show superior reactivity and durability in oxygen evolution reactions. The series of Ni-Mo-based electrocatalysts presents a competitive overpotential of 296 mV at 10 mA·cm⁻² for an OER in 1.0 M KOH, corresponding with a low Tafel slope of 121 mV dec⁻¹. The three-dimensional nanostructure has a large double-layer capacitance and plenty of channels for ion transfer, which demonstrates more active sites and improved charge transmission. This study provides a valuable reference for the development of non-precious catalysts for water splitting. Full article

(This article belongs to the Special Issue Development of Nanomaterials for Energy and Environmental Applications)

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13 pages, 2941 KiB

Open AccessArticle

Thermoacid Behavior of Serpentinite of the Zhitikarinsky Deposit (Kazakhstan)

by Abdrazak Auyeshov, Kazhymuhan Arynov, Chaizada Yeskibayeva, Kurmanbek Alzhanov and Yerkebulan Raiymbekov

Molecules 2024, 29(16), 3965; https://doi.org/10.3390/molecules29163965 - 22 Aug 2024

Viewed by 598

Abstract

Thermoacid behavior of serpentinite from the Zhitikarinsky field (g. Zhitikara, Kazakhstan). The character of dissolution of heat-treated serpentinite in a narrow temperature range of 600–750 °C is investigated, where the crystal lattice of the structural structure of chrysotile in sulfuric acid is destroyed. [...] Read more.

Thermoacid behavior of serpentinite from the Zhitikarinsky field (g. Zhitikara, Kazakhstan). The character of dissolution of heat-treated serpentinite in a narrow temperature range of 600–750 °C is investigated, where the crystal lattice of the structural structure of chrysotile in sulfuric acid is destroyed. The X-ray and chemical analysis of the products of dissolution of heat-treated serpentinite at 600 °C, 725 °C and 750 °C in sulfuric acid solution show that the reason for the increase in the reactivity of heat-treated serpentinite at 725 °C and 750 °C with respect to the acidic medium and the degree of magnesium extraction into sulfate solution is the formation of periclase (MgO) in the serpentinite composition after heat treatment of them within a temperature range of 600–750 °C. The results were discussed using data obtained by conducting a thermodynamic evaluation of probable reactions during the thermoacid treatment of serpentinite, phase compressions of heat-treated serpentinite at 600–750 °C, and after its acid treatment at 1.0 M H₂SO₄. Full article

(This article belongs to the Special Issue Analytical Chemistry in Asia)

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12 pages, 3842 KiB

Open AccessArticle

Cascade Hydroxyl Radical-Generating and Ferroptosis-Inducing Nanofiber System for the Therapy of Oral Squamous Cell Carcinoma

by JiHye Park, Qiaojun Hao, Da In Jeong, Hyun-Jin Kim, Sungyun Kim, Song Yi Lee, Seongnam Chu, Usok Hyun and Hyun-Jong Cho

Molecules 2024, 29(16), 3964; https://doi.org/10.3390/molecules29163964 - 22 Aug 2024

Cited by 1 | Viewed by 879

Abstract

Nanofiber (NF) membrane systems that can provide cascade catalytic reaction and ferroptosis induction were developed for oral cancer therapy. Glucose oxidase (GOx) and aminoferrocene (AF) were introduced into the NF system for glucose deprivation/H₂O₂ generation and OH radical generation, respectively. [...] Read more.

Nanofiber (NF) membrane systems that can provide cascade catalytic reaction and ferroptosis induction were developed for oral cancer therapy. Glucose oxidase (GOx) and aminoferrocene (AF) were introduced into the NF system for glucose deprivation/H₂O₂ generation and OH radical generation, respectively. GOx offers starvation therapy and AF (including iron) provides chemodynamic therapy/ferroptosis for combating oral cancer. GOx (water-soluble) and AF (poorly water-soluble) molecules were successfully entrapped in the NF membrane via an electrospinning process. GOx and AF were incorporated into the polyvinyl alcohol (PVA)-based NF, resulting in PVA/GOx/AF NF with fast disintegration and immediate drug-release properties. In oral squamous cell carcinoma (YD-9 cells), the PVA/GOx/AF NF group exhibited higher cytotoxicity, antiproliferation potential, cellular ROS level, apoptosis induction, lipid ROS level, and malondialdehyde level compared to the other NF groups. The electrospun PVA/GOx/AF NF can be directly applied to oral cancer without causing pain, offering starvation/chemodynamic therapy and ferroptosis induction. Full article

(This article belongs to the Special Issue Nanomaterials in Cancer Therapy: Synthesis, Mechanisms, and Applications)

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21 pages, 18571 KiB

Open AccessArticle

Hydrogen Production from Methanol Steam Reforming over Fe-Modified Cu/CeO₂ Catalysts

by Grzegorz Słowik, Marek Rotko, Janusz Ryczkowski and Magdalena Greluk

Molecules 2024, 29(16), 3963; https://doi.org/10.3390/molecules29163963 - 22 Aug 2024

Viewed by 1296

Abstract

Fe-modified Cu catalysts with CeO₂ support, prepared by the impregnation method, were subjected to physicochemical analysis and catalytic tests in the steam reforming of methanol (SRM). Physicochemical studies of the catalysts were carried out using the XRF, TEM, STEM-EDS, XRD, TPR and [...] Read more.

Fe-modified Cu catalysts with CeO₂ support, prepared by the impregnation method, were subjected to physicochemical analysis and catalytic tests in the steam reforming of methanol (SRM). Physicochemical studies of the catalysts were carried out using the XRF, TEM, STEM-EDS, XRD, TPR and nitrogen adsorption/desorption methods. XRD, TEM studies and catalytic tests of the catalysts were carried out at two reduction temperatures, 260 °C and 400 °C, to determine the relationship between the form and oxidation state of the active phase of the catalysts and the catalytic properties of these systems in the SRM. Additionally, the catalysts after the reaction were analysed for the changes in the structure and morphology using TEM methods. The presented results show that the composition of the catalysts, morphology, structure, form and oxidation state of the Cu and Fe active metals in the catalysts and the reaction temperature significantly impact their activity, selectivity and stability in the SRM process. The gradual deactivation of the studied catalysts under SRM conditions could result from the forming of carbon deposits and/or the gradual oxidation of the copper and iron phases under the reaction conditions. Full article

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13 pages, 2772 KiB

Open AccessArticle

Low-Cost Ni-W Catalysts Supported on Glucose/Carbon Nanotube Hybrid Carbons for Sustainable Ethylene Glycol Synthesis

by Rafael G. Morais, Lucília S. Ribeiro, José J. M. Órfão and Manuel Fernando R. Pereira

Molecules 2024, 29(16), 3962; https://doi.org/10.3390/molecules29163962 - 22 Aug 2024

Viewed by 962

Abstract

The production of ethylene glycol (EG) from cellulose has garnered significant attention in recent years as an attractive alternative to fossil fuels due to the potential of cellulose as a renewable and sustainable feedstock. In this work, to the best of our knowledge, [...] Read more.

The production of ethylene glycol (EG) from cellulose has garnered significant attention in recent years as an attractive alternative to fossil fuels due to the potential of cellulose as a renewable and sustainable feedstock. In this work, to the best of our knowledge, a series of low-cost Ni-W bimetallic catalysts supported on glucose/carbon nanotube hybrid carbons were synthesised for the first time and employed to transform cellulose into EG. Two different strategies were combined for the preparation of the carbons: the activation and addition of carbon nanotubes (CNTs) to obtain a hybrid material (AG-CNT). The catalytic conversion process proceeded through cellulose hydrolysis to glucose, followed by glucose retro-aldol condensation to glycolaldehyde and its subsequent hydrogenation to EG. Through the optimisation of the catalyst’s properties, particularly the metals’ content, a good synergistic effect of C-C bond cleavage and hydrogenation capabilities was assured, resulting in the highly selective production of EG. The balance between Ni and W active sites was confirmed to be a crucial parameter. Thus, total cellulose conversion (100%) was achieved with EG yields of 60–62%, which are amongst the best yields ever reported for the catalytic conversion of cellulose into EG via carbon-supported catalysts. Full article

(This article belongs to the Special Issue Design, Synthesis and Applications of Novel Transition Metal Catalysts)

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16 pages, 2541 KiB

Open AccessArticle

Antibacterial Efficacy and Characterization of Silver Nanoparticles Synthesized via Methanolic Extract of Fomes fomentarius L. Fr.

by Valentina Pavić, Elvira Kovač-Andrić, Ivan Ćorić, Stella Rebić, Zvonimir Užarević and Vlatka Gvozdić

Molecules 2024, 29(16), 3961; https://doi.org/10.3390/molecules29163961 - 22 Aug 2024

Viewed by 1027

Abstract

Green synthesis employs environmentally friendly, biodegradable substances for the production of nanomaterials. This study aims to develop an innovative method for synthesizing silver nanoparticles (AgNPs) using a methanolic extract of Fomes fomentarius L. Fr. as the reducing agent and to assess the potential [...] Read more.

Green synthesis employs environmentally friendly, biodegradable substances for the production of nanomaterials. This study aims to develop an innovative method for synthesizing silver nanoparticles (AgNPs) using a methanolic extract of Fomes fomentarius L. Fr. as the reducing agent and to assess the potential antibacterial properties of the resulting nanoparticles. The successful synthesis of AgNPs was confirmed through characterization techniques such as UV-visible (UV-Vis) spectrophotometry, Fourier-transform infrared spectroscopy (FT-IR), and powder X-ray diffraction (PXRD). The UV-Vis analysis revealed an absorption peak at 423 nm, while FT-IR identified key phytochemical compounds involved in the reduction process. PXRD analysis indicated a face-centered cubic (fcc) structure with prominent peaks observed at 2θ = 38°, 44.6°, 64.6°, and 78°, confirming the crystalline nature of the AgNPs, with a crystallite diameter of approximately 24 nm, consistent with TEM analysis. The synthesized AgNPs demonstrated significant antibacterial activity, particularly against S. aureus, with higher efficacy against gram-positive bacteria. Full article

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UV-Vis spectra of AgNPs synthesized via F. fomentarius L. Fr. extract at different time intervals. Full article ">Figure 2
FT-IR spectra of dried Fomes fomentarius L. Fr. extract and AgNPs synthesized via F. fomentarius L. Fr. extract. Full article ">Figure 3
PXRD pattern of AgNPs synthesized via F. fomentarius L. Fr. extract. Full article ">Figure 4
(A) TEM image showing the AgNPs synthesized via F. fomentarius L. Fr. extract with a size distribution of approximately 23.6 ± 3.5 nm. (B) TEM image processed using the “Find Edges” option in the Fiji program (an extension of the ImageJ program). The edge detection enhances the sharpness of the image by defining the particle boundaries more clearly against the background, making the nanoparticles appear more distinct. The scale bar represents 100 nm in A and B images. (C) Average particle size of AgNPs synthesized via F. fomentarius L. Fr. extract. Full article ">Figure 5
Fomes fomentarius L. Fr. Full article ">

19 pages, 5518 KiB

Open AccessArticle

Agroprospecting of Biowastes: Globe Artichoke (Cynara scolymus L. Cultivar Tema, Asteraceae) as Potential Source of Bioactive Compounds

by Jorge M. Alves-Silva, Mónica Zuzarte, Lígia Salgueiro, Emma Cocco, Valentina Ghiani, Danilo Falconieri, Delia Maccioni and Andrea Maxia

Molecules 2024, 29(16), 3960; https://doi.org/10.3390/molecules29163960 - 22 Aug 2024

Viewed by 1172

Abstract

Artichokes (Cynara scolymus L.) are valuable foods, thanks to their health benefits, but they generate significant waste during their production, harvesting, and processing, which poses sustainability issues. This study applied an agroprospecting approach to convert Tema artichoke biowaste (TB) into valuable resources, [...] Read more.

Artichokes (Cynara scolymus L.) are valuable foods, thanks to their health benefits, but they generate significant waste during their production, harvesting, and processing, which poses sustainability issues. This study applied an agroprospecting approach to convert Tema artichoke biowaste (TB) into valuable resources, starting from a global perspective of the production chain to the targeted applications based on chemical and biological analysis. The major TB was identified in the outer bracts of the immature flower heads, which were collected throughout the harvesting season, extracted, and analyzed. The most abundant compounds were phenolic acids including chlorogenic acid and caffeoylquinic derivatives. Among flavonoids, cynaroside was the most abundant compound. Multivariate analysis distinguished batches by collection period, explaining 77.7% of the variance, with most compounds increasing in concentration later in the harvest season. Subsequently, TB extracts were analyzed for their potential in wound healing and anti-aging properties. Fibroblasts were used to assess the effect of selected extracts on cell migration through a scratch wound assay and on cellular senescence induced by etoposide. The results show a significant decrease in senescence-associated β-galactosidase activity, γH2AX nuclear accumulation, and both p53 and p21 protein levels. Overall, this study ascribes relevant anti-skin aging effects to TB, thus increasing its industrial value in cosmeceutical and nutraceutical applications. Full article

(This article belongs to the Special Issue Advances in Functional Foods)

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Biplot and PCA analysis of the detected compounds in the globe artichoke agro-wastes, from batches A to H. In the biplot (A), each dot represents a batch of replicates. The PCA (B) indicates the variable contribution. Colors tending toward red indicate better-represented variables, while gradually lighter colors toward blue shades indicate less-represented variables. Full article ">Figure 2
Safety profile of the hydroalcoholic extract from globe artichoke agro-wastes (batches A, E, and F) on fibroblasts assessed by the resazurin assay. Full article ">Figure 3
Effect of hydroalcoholic extracts from globe artichoke agro-wastes (batches A, E, and F) on fibroblasts migration assessed by the wound healing assay. (A) Images acquired by phase-contrast microscopy immediately after wound induction (0 h) and after 18 h of incubation; (B) histograms showing the quantified wound area of the different extracts compared with the control (CT). Scale bar: 100 µm. Full article ">Figure 4
Effect of the hydroalcoholic extracts obtained from globe artichoke agro-wastes (batches A, E, and F) on NIH/3T3 fibroblasts senescence-associated β-galactosidase activity (A). Histograms showing the quantitative analysis using ImageJ software (B). Statistical significance * p < 0.05, ** p < 0.01 determined by one-way ANOVA followed by Dunnett’s multiple comparisons test. Eto—etoposide (12.5 µM); Scale bar: 100 µm. Full article ">Figure 5
Effect of the hydroalcoholic extracts from globe artichoke agro-wastes (batches A, E, and F) on NIH/3T3 fibroblasts nuclear accumulation of the phosphorylated form of H2AX (γ-H2AX). Representative confocal images (A) and corresponding histograms from quantitave analysis (B). Statistical significance ** p < 0.01, *** p < 0.001 by one-way ANOVA followed by Dunnett’s multiple comparisons test. Eto—etoposide (12.5 µM); Scale bar: 10 µm. Full article ">Figure 6
Effect of the hydroalcoholic extracts from globe artichoke agro-wastes (batches A, E, and F) on protein levels of p53 (A,B) and p21 (A,C). Tubulin used as loading control and results normalized to etoposide. * p < 0.05, ** p < 0.01, *** p < 0.001 by one-way ANOVA, followed by Dunnett’s multiple comparison test. Eto—etoposide (12.5 µM). Full article ">

14 pages, 4852 KiB

Open AccessArticle

Multi-Functional Repair and Long-Term Preservation of Paper Relics by Nano-MgO with Aminosilaned Bacterial Cellulose

by Hongyan Mou, Ting Wu, Xingxiang Ji, Hongjie Zhang, Xiao Wu and Huiming Fan

Molecules 2024, 29(16), 3959; https://doi.org/10.3390/molecules29163959 - 22 Aug 2024

Viewed by 979

Abstract

Paper relics, as carrieres of historical civilization’s records and inheritance, could be severely acidic and brittle over time. In this study, the multi-functional dispersion of nanometer magnesium oxide (MgO) carried by 3-aminopropyl triethoxysilane-modified bacterial cellulose (KH550-BC) was applied in the impregnation process to [...] Read more.

Paper relics, as carrieres of historical civilization’s records and inheritance, could be severely acidic and brittle over time. In this study, the multi-functional dispersion of nanometer magnesium oxide (MgO) carried by 3-aminopropyl triethoxysilane-modified bacterial cellulose (KH550-BC) was applied in the impregnation process to repair aged paper, aiming at solving the key problems of anti-acid and strength recovery in the protection of ancient books. The KH550-BC/MgO treatment demonstrated enhanced functional efficacy in repairing aged paper, attributed to the homogeneous and stable distribution of MgO within the nanofibers of BC networks, with minimal impact on the paper’s wettability and color. Furthermore, the treatment facilitated the formation of adequate alkali reserves and hydrogen bonding, resulting in superior anti-aging properties in the treated paper during prolonged preservation. Even after 30 days of hygrothermal aging tests, the paper repaired by KH550-BC/MgO was still in a gently alkaline environment (pH was about 7.56), alongside a 32.18% elevation compared to the untreated paper regarding the tear index. The results of this work indicate that KH550-BC/MgO is an effective reinforcement material for improving the long-term restoration of ancient books. Full article

(This article belongs to the Special Issue Chemical Conservation of Paper-Based Cultural Heritage)

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27 pages, 3246 KiB

Open AccessArticle

Exclusive Solvent-Controlled Regioselective Catalytic Synthesis of Potentially Bioactive Imidazolidineiminodithiones: NMR Analysis, Computational Studies and X-ray Crystal Structures

by Ziad Moussa, Sara Saada, Alejandro Perez Paz, Ahmed Alzamly, Zaher M. A. Judeh, Aaesha R. Alshehhi, Aisha Khudhair, Salama A. Almheiri, Harbi Tomah Al-Masri and Saleh A. Ahmed

Molecules 2024, 29(16), 3958; https://doi.org/10.3390/molecules29163958 - 22 Aug 2024

Viewed by 1160

Abstract

Herein, we describe the first consistent regiospecific reaction of isothiocyanates with a variety of substituted N-arylcyanothioformamides in a 1:1 molar ratio to generate a series of imidazolidineiminodithiones decorated with a multitude of functional groups on both aromatic rings. The reaction is carried [...] Read more.

Herein, we describe the first consistent regiospecific reaction of isothiocyanates with a variety of substituted N-arylcyanothioformamides in a 1:1 molar ratio to generate a series of imidazolidineiminodithiones decorated with a multitude of functional groups on both aromatic rings. The reaction is carried out at room temperature using a 20 mol% catalytic amount of triethylamine with DMF as the solvent to selectively form the mentioned products with exclusive regioselectivity. The methodology features wide substrate scope, no requirement for chromatography, and good to high reaction yields. The products were isolated by simple ether/brine extraction and the structures were verified by multinuclear NMR spectroscopy and high accuracy mass measurements. The first conclusive molecular structure elucidation of the observed regioisomer was established by single-crystal X-ray diffraction analysis. Likewise, the tautomer of the N-arylcyanothioformamide reactant was proven by X-ray diffraction analysis. Density functional theory computations at the B3LYP-D4/def2-TZVP level in implicit DMF solvent were conducted to support the noted regiochemical outcome and proposed mechanism. Full article

(This article belongs to the Section Organic Chemistry)

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Expanded and truncated 1HNMR spectra showing the N-H protons as representative signals to demonstrate product distribution of the imidazolidineiminodithione 18a vs. the thiazolidinethione product 17a using various solvents. Full article ">Figure 2
Preparation of variously substituted imidazolidineiminodithiones derivatives 18a–z, 18a′–z′, and 18a″–18f″. All products shown were isolated from the reaction mixture by ether/aqueous workup. Full article ">Figure 3
Assigned 1H- and 13C-NMR chemical shifts of imidazolidineiminodithione 18g′. Full article ">Figure 4
Thermal ellipsoid plots of 5-imino-1-(4-nitrophenyl)-3-(p-tolyl)imidazolidine-2,4-dithione (18g′) (Deposition Number 2246320) with ellipsoids drawn at the 50% probability level. For the bond distances (Å) and angles (deg), see the <a href="#app1-molecules-29-03958" class="html-app">Supporting Information Section</a>. Full article ">Scheme 1
Previous preparation and some selected reactions of imidazolidineiminothiones 3. Full article ">Scheme 2
Ketcham’s ring-closing reactions of N-phenylcyanothioformamide (1a) and N-methyl-(1a′) with aryl (16a) and alkyl (16a′) under various conditions. Full article ">Scheme 3
(a) Preparation of variously substituted N-arylcyanothioformamides 1a–g and (b) commercial isothiocyanates 16a–i coupling partners and preparation of isothiocyanate 16j. Full article ">Scheme 4
Synthetic approach to prepare different derivatives of variously substituted regioisomerically pure imidazolidineiminodithiones 18a–z, 18a′–z′, and 18a″–18e″. Full article ">Scheme 5
Proposed mechanism for the formation of substituted imidazolidineiminodithiones 18 from isothiocyanates 16 and N-arylcyanothioformamides 1. The reaction “path b” is dominant. Full article ">

13 pages, 1279 KiB

Open AccessReview

The Phytochemical, Quercetin, Attenuates Nociceptive and Pathological Pain: Neurophysiological Mechanisms and Therapeutic Potential

by Mamoru Takeda, Yukito Sashide, Ryou Toyota and Haruka Ito

Molecules 2024, 29(16), 3957; https://doi.org/10.3390/molecules29163957 - 21 Aug 2024

Cited by 3 | Viewed by 1429

Abstract

Although phytochemicals are plant-derived toxins that are primarily produced as a form of defense against insects or microbes, several lines of study have demonstrated that the phytochemical, quercetin, has several beneficial biological actions for human health, including antioxidant and inflammatory effects without side [...] Read more.

Although phytochemicals are plant-derived toxins that are primarily produced as a form of defense against insects or microbes, several lines of study have demonstrated that the phytochemical, quercetin, has several beneficial biological actions for human health, including antioxidant and inflammatory effects without side effects. Quercetin is a flavonoid that is widely found in fruits and vegetables. Since recent studies have demonstrated that quercetin can modulate neuronal excitability in the nervous system, including nociceptive sensory transmission via mechanoreceptors and voltage-gated ion channels, and inhibit the cyclooxygenase-2-cascade, it is possible that quercetin could be a complementary alternative medicine candidate; specifically, a therapeutic agent against nociceptive and pathological pain. The focus of this review is to elucidate the neurophysiological mechanisms underlying the modulatory effects of quercetin on nociceptive neuronal activity under nociceptive and pathological conditions, without inducing side effects. Based on the results of our previous research on trigeminal pain, we have confirmed in vivo that the phytochemical, quercetin, demonstrates (i) a local anesthetic effect on nociceptive pain, (ii) a local anesthetic effect on pain related to acute inflammation, and (iii) an anti-inflammatory effect on chronic pain. In addition, we discuss the contribution of quercetin to the relief of nociceptive and inflammatory pain and its potential clinical application. Full article

(This article belongs to the Special Issue Bioactive Phenolic and Polyphenolic Compounds, Volume III)

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Possible molecular targets for phytochemicals as local anesthetic agents. When locally applied to peripheral tissues, quercetin inhibits the development of both generator potentials and action potentials in the peripheral terminal of primary afferents after nociceptive stimulation via the inhibition of mechanosensitive ionic channels (acid-sensing ion channel [ASIC] and transient receptor potential ankyrin 1 [TRPA1]), voltage-gated sodium (Nav) channels, and the facilitation of voltage-gated potassium (Kv) channels. The potency of quercetin is almost equal to that of Nav channel blockers, such as the commonly used local anesthetics, e.g., lidocaine. Cav = voltage-gated calcium, TG = trigeminal ganglion, SpVc = trigeminal spinal nucleus caudalis. Full article ">Figure 2
Local anesthetic effect of quercetin under inflammatory conditions. The inhibitory effect of quercetin on inflamed tissues may be caused by the suppression of the firing frequency of action potentials by the inhibition of nociceptive mechanosensitive channels (ASIC and TRPA1), the inhibition of Nav channels, the inhibition of T-type Cav channels, and the opening of Kv channels. The inhibitory potency of quercetin on the discharge frequency is significantly higher than that of lidocaine; therefore, quercetin has a strong local anesthetic effect on inflamed tissues and is expected to be used in the field of complementary and alternative medicine. EPSP = excitatory postsynaptic potential. Full article ">Figure 3
The systemic administration of quercetin inhibits inflammatory pain. Following peripheral inflammation, inflammatory mediators, such as prostaglandin E2 (PGE2), bind to G-protein-coupled E-type prostanoid (EP) receptors and induce the activation of protein kinase (PK) A and PKC in nociceptive peripheral terminals, leading to the phosphorylation of mechanosensitive (TRPA1, ASIC), Nav, and Kv channels. As a result, the activation threshold for transducer channels, such as the TRP channel family, is reduced, and the membrane excitability of the peripheral terminal increases, resulting in a high frequency of action potentials being conducted to presynaptic central terminals of the SpVc. This results in the release of a large amount of glutamate into the synaptic cleft, which binds to upregulated postsynaptic glutamate receptors, augmenting EPSPs, causing a barrage of action potentials to be conducted to higher centers of pain pathways, and creating a state of heightened sensitivity, termed peripheral sensitization. The systemic administration of quercetin attenuates the mechanical inflammatory hyperalgesia associated with the hyperexcitability of SpVc neurons via the inhibition of peripheral cyclooxygenase-2 (Cox-2) cascade signaling pathways, and this effect restores the SpVc neuronal hyperactivity to control levels. The systemic administration of quercetin also inhibits ASIC, Nav, and Cav channels and opens Kv channels in the peripheral terminals. The potency of quercetin is almost equal to the commonly used analgesics, non-steroidal anti-inflammatory drugs. Full article ">

16 pages, 20293 KiB

Open AccessArticle

Physicochemical Characteristics of Residual Carbon and Inorganic Minerals in Coal Gasification Fine Slag

by Le Li, Jing Liu, Xiangyang Li, Zeyu Peng, Chun Han, Wenhao Lian, Bin Xue, Chenmin Gao, Qian Zhang and Wei Huang

Molecules 2024, 29(16), 3956; https://doi.org/10.3390/molecules29163956 - 21 Aug 2024

Cited by 1 | Viewed by 976

Abstract

Investigating the physicochemical properties and embedding forms of residual carbon (RC) and slag particles (SPs) in coal gasification fine slag (FS) is the basis for achieving its separation and utilization. An in-depth understanding of their compositional characteristics allows for targeted treatment and utilization [...] Read more.

Investigating the physicochemical properties and embedding forms of residual carbon (RC) and slag particles (SPs) in coal gasification fine slag (FS) is the basis for achieving its separation and utilization. An in-depth understanding of their compositional characteristics allows for targeted treatment and utilization programs for different components. In this work, the physicochemical properties and embedding forms of RC and SPs in FS were systematically investigated. An innovative calculation method is proposed to determine the mass fraction of dispersed carbon particles, dispersed mineral-rich particles, and carbon–ash combined particles by using a high-temperature heating stage coupled with an optical microscope. The unburned RC with a rough, loose surface and a well-developed pore structure acted as a framework in which the smaller spherical SPs with a smooth surface were embedded. In addition, the sieving pretreatment process facilitated the enrichment of the RC. Moreover, the RC content showed significant dependencies according to the FS particle size. For FS with a particle size of 0.075–0.150 mm, the mass proportions of dispersed carbon, ash particles, and the carbon–ash combination were 15.19%, 38.72%, and 46.09%, respectively. These findings provide basic data and reliable technical support for the subsequent carbon and ash separation process and the comprehensive utilization of coal gasification slag. Full article

(This article belongs to the Special Issue Separation, Recovery and Conversion of Low-Quality Materials via Physicochemical Technology)

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Particle size distribution of (a) FS, (b) SPs, and (c) RC particles. Full article ">Figure 2
(a) Adsorption/desorption isotherms, (b) microporous size distribution, and (c) macroporous size distribution of the FS, RC, and SPs. Full article ">Figure 3
SEM images of the (a) FS, (b) RC, and (c) SPs (the resolution in 1 is 20 μm, while the resolution in 2 and 3 is 3 μm). Full article ">Figure 4
XRD pattern of the FS, RC, and SPs. Full article ">Figure 5
FT-IR spectra of FS, RC, and SPs. Full article ">Figure 6
The morphology changes and decrease in area of RC, SPs and FS on 100–200 mesh. (The (a1,b1,c1) represent the morphology changes of RC, SPs, and FS, respectively. The (a2,b2,c2) represent the area changes of RC, SPs, and FS, respectively). Full article ">Figure 7
Sample schematic of FS, SPs, and RC. Full article ">

17 pages, 5810 KiB

Open AccessArticle

Complexes of Hydrogen Peroxide, the Simplest Chiral Molecule, with L- and D-Serine Enantiomers and Their Clusters: MP2 and DFT Calculations

by Yurii A. Borisov, Sergey S. Kiselev, Mikhail I. Budnik and Lubov V. Snegur

Molecules 2024, 29(16), 3955; https://doi.org/10.3390/molecules29163955 - 21 Aug 2024

Viewed by 821

Abstract

The interaction between natural amino acids and hydrogen peroxide is of paramount importance due to the widespread use of hydrogen peroxide in biological and environmentally significant processes. Given that both amino acids and hydrogen peroxide occur in nature in two enantiomeric forms, it [...] Read more.

The interaction between natural amino acids and hydrogen peroxide is of paramount importance due to the widespread use of hydrogen peroxide in biological and environmentally significant processes. Given that both amino acids and hydrogen peroxide occur in nature in two enantiomeric forms, it is crucial to investigate the formation of complexes between them, considering the role of molecular chirality. In this work, we report a theoretical study on the hydrogen peroxide enantiomers and their interactions with L- and S-serine and their clusters. We aimed to evaluate the non-covalent interactions between each hydrogen peroxide enantiomer and the L- and D-enantiomers of the non-essential amino acid serine and their clusters. First, the potential energy surfaces (PES) of transitions between enantiomers of the simplest chiral molecule, hydrogen peroxide, in the gas phase and in aqueous solution were studied using the Møller–Plesset theory method MP2/aug-cc-pVDZ. The activation energies of such transitions were calculated. The interactions of both hydrogen peroxide enantiomers (P and M) with L- and D-serine enantiomers were analyzed by density functional theory (DFT) with ωb97xd/6-311+G**, B3Lyp/6-311+G**, B3P86/6-311+G**, and M06/6-311+G** functionals. We found that both enantiomers of hydrogen peroxide bind more strongly to L-serine and its clusters than to D-serine, especially highlighting that the L form is the predominant natural form of this and other chiral amino acids. The optimized geometric parameters, interaction energies, and HOMO-LUMO energies for various complexes were estimated. Furthermore, circular dichroism (CD) spectra, which are optical chirality characteristics, were simulated for all the complexes under study. Full article

(This article belongs to the Special Issue Theoretical Study of Inorganic Complexes: Recent Advances and Future Perspectives)

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25 pages, 442 KiB

Open AccessReview

Current Treatments, Emerging Therapeutics, and Natural Remedies for Inflammatory Bowel Disease

by Karma Yeshi, Tenzin Jamtsho and Phurpa Wangchuk

Molecules 2024, 29(16), 3954; https://doi.org/10.3390/molecules29163954 - 21 Aug 2024

Cited by 3 | Viewed by 1837

Abstract

Inflammatory bowel disease (IBD) is a chronic, lifelong disorder characterized by inflammation of the gastrointestinal (GI) tract. The exact etiology of IBD remains incompletely understood due to its multifaceted nature, which includes genetic predisposition, environmental factors, and host immune response dysfunction. Currently, there [...] Read more.

Inflammatory bowel disease (IBD) is a chronic, lifelong disorder characterized by inflammation of the gastrointestinal (GI) tract. The exact etiology of IBD remains incompletely understood due to its multifaceted nature, which includes genetic predisposition, environmental factors, and host immune response dysfunction. Currently, there is no cure for IBD. This review discusses the available treatment options and the challenges they present. Importantly, we examine emerging therapeutics, such as biologics and immunomodulators, that offer targeted treatment strategies for IBD. While many IBD patients do not respond adequately to most biologics, recent clinical trials combining biologics with small-molecule drugs (SMDs) have provided new insights into improving the IBD treatment landscape. Furthermore, numerous novel and specific therapeutic targets have been identified. The high cost of IBD drugs poses a significant barrier to treatment, but this challenge may be alleviated with the development of more affordable biosimilars. Additionally, emerging point-of-care protein biomarkers from serum and plasma are showing potential for enhancing the precision of IBD diagnosis and prognosis. Several natural products (NPs), including crude extracts, small molecules, and peptides, have demonstrated promising anti-inflammatory activity in high-throughput screening (HTS) systems and advanced artificial intelligence (AI)-assisted platforms, such as molecular docking and ADMET prediction. These platforms are advancing the search for alternative IBD therapies derived from natural sources, potentially leading to more affordable and safer treatment options with fewer side effects. Full article

(This article belongs to the Topic Natural Bioactive Compounds as a Promising Approach to Mitigating Oxidative Stress)

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11 pages, 2161 KiB

Open AccessArticle

Modeling and Optimization of Ellagic Acid from Chebulae Fructus Using Response Surface Methodology Coupled with Artificial Neural Network

by Junkai Wu, Fan Yang, Liyang Guo and Zunlai Sheng

Molecules 2024, 29(16), 3953; https://doi.org/10.3390/molecules29163953 - 21 Aug 2024

Cited by 1 | Viewed by 699

Abstract

The dried ripe fruit of Terminalia chebula Retz. is a common Chinese materia medica, and ellagic acid (EA), isolated from the plant, is an important bioactive component for medicinal purposes. This study aimed to delineate the optimal extraction parameters for extracting the EA [...] Read more.

The dried ripe fruit of Terminalia chebula Retz. is a common Chinese materia medica, and ellagic acid (EA), isolated from the plant, is an important bioactive component for medicinal purposes. This study aimed to delineate the optimal extraction parameters for extracting the EA content from Chebulae Fructus (CF), focusing on the variables of ethanol concentration, extraction temperature, liquid–solid ratio, and extraction time. Utilizing a combination of the response surface methodology (RSM) and an artificial neural network (ANN), we systematically investigated these parameters to maximize the EA extraction efficiency. The extraction yields for EA obtained under the predicted optimal conditions validated the efficacy of both the RSM and ANN models. Analysis using the ANN-predicted data showed a higher coefficient of determination (R²) value of 0.9970 and a relative error of 0.79, compared to the RSM’s 2.85. The optimal conditions using the ANN are an ethanol concentration of 61.00%, an extraction temperature of 77 °C, a liquid–solid ratio of 26 mL g⁻¹ and an extraction time of 103 min. These findings significantly enhance our understanding of the industrial-scale optimization process for EA extraction from CF. Full article

(This article belongs to the Section Natural Products Chemistry)

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18 pages, 5667 KiB

Open AccessArticle

Theoretical Investigation of the Pyridinium-Inspired Catalytic Dehydration of Heptafluoro-Iso-Butyramide for the Synthesis of Environmentally Friendly Insulating Gas Heptafluoro-Iso-Butyronitrile

by Jiageng Xiong, Hua Hou and Baoshan Wang

Molecules 2024, 29(16), 3952; https://doi.org/10.3390/molecules29163952 - 21 Aug 2024

Viewed by 740

Abstract

Heptafluoro-iso-butyronitrile (i-C₃F₇CN) represents a feasible eco-friendly replacement gas for the most potent greenhouse gas sulfur hexafluoride in various high-voltage power transmission equipment. The reaction mechanisms for the in situ synthesis of i-C₃F₇CN [...] Read more.

Heptafluoro-iso-butyronitrile (i-C₃F₇CN) represents a feasible eco-friendly replacement gas for the most potent greenhouse gas sulfur hexafluoride in various high-voltage power transmission equipment. The reaction mechanisms for the in situ synthesis of i-C₃F₇CN from heptafluoro-iso-butyramide [i-C₃F₇C(O)NH₂] in the presence of trifluoroacetic anhydride (TFAA) and pyridine (Py) in dimethylformamide solution have been studied within density functional theory with M06-2X exchange–correlation functional with the 6-311++G(d,p) basis set and the high-level ab initio complete basis set quadratic CBS-QB3 method. It is revealed that the unimolecular dehydration of i-C₃F₇C(O)NH₂ can be catalyzed efficiently by TFAA in terms of both kinetic and thermodynamic aspects, producing i-C₃F₇CN and trifluoroacetic acid (TFA). Furthermore, Py is capable of reducing the energy barrier of the rate-determining step through hydrogen abstraction to form pyridinium hydrogen. The synergic effect of the TFAA/Py co-catalyst plays a pivotal role in the production of i-C₃F₇CN as the Gibbs free energy barrier can be lowered by more than 40 kcal/mol with the ratio of TFAA:2Py, in accordance with the experimental observation. The present theoretical work provides new insights into the rational design on the novel catalysts for large-scale synthesis of the perfluorinated nitriles. Full article

(This article belongs to the Special Issue Multiconfigurational and DFT Methods Applied to Chemical Systems—2nd Edition)

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Full article ">Figure 1
Geometrical parameters for various species involved in the dehydration reaction of i-C3F7C(O)NH2 optimized at the M06-2X/6-311++G(d,p) level of theory. Bond distances are in Å and angles are in degrees. Full article ">Figure 2
Geometrical parameters for the species involved in the energetically favorable paths for the i-C3F7C(O)NH2+2Py reaction optimized at the M06-2X/6-311++G(d,p) level of theory. Bond distances are in Å and angles are in degrees. Full article ">Figure 3
Geometrical parameters for various species involved in the reaction of i-C3F7C(O)NH2 with TFAA optimized at the M06-2X/6-311++G(d,p) level of theory. Bond distances are in Å and angles are in degrees. Full article ">Figure 4
Optimized geometrical parameters for various species involved in the reaction of E-i-C3F7C(O)NH2+TFAA+1Py at the M06-2X/6-311++G(d,p) level of theory. Bond distances are in Å and angles are in degrees. Full article ">Figure 5
Geometrical parameters for the species involved in the energetically favorable paths for the Z-i-C3F7C(O)NH2+TFAA+1Py reaction optimized at the M06-2X/6-311++G(d,p) level of theory. Bond distances are in Å and angles are in degrees. Full article ">Figure 6
Geometrical parameters for the species involved in the energetically favorable paths for the i-C3F7C(O)NH2+TFAA+2Py reaction optimized at the M06-2X/6-311++G(d,p) level of theory. Bond distances are in Å and angles are in degrees. Full article ">Figure 7
Correlations between the DL-CBS-QB3 and the M06-2X/6-311++G(d,p) energies (in kcal/mol). Solid triangles: for the reaction of i-C3F7C(O)NH2+TFAA. Open squares: for the dehydration reaction of i-C3F7C(O)NH2. Full article ">Scheme 1
Mechanistic routes for the dehydration of i-C3F7C(O)NH2 to produce i-C3F7CN as catalyzed by trifluoroacetic anhydride and pyridine. Full article ">Scheme 2
Gibbs free energy profiles (in kcal/mol) for the unimolecular dehydration reaction of i-C3F7C(O)NH2 to form i-C3F7CN calculated at the M06-2X/6-311++G(d,p) level of theory. Full article ">Scheme 3
Gibbs free energy profiles (in kcal/mol) for the reaction of i-C3F7C(O)NH2+2Py calculated at the M06-2X/6-311++G(d,p) level of theory. Full article ">Scheme 4
Gibbs free energy profiles (in kcal/mol) for the reaction of i-C3F7C(O)NH2 with TFAA in DMF solution calculated at the M06-2X/6-311++G(d,p) level of theory. Full article ">Scheme 5
Gibbs free energy profiles (in kcal/mol) for the reaction of E-i-C3F7C(O)NH2+TFAA+1Py calculated at the M06-2X/6-311++G(d,p) level of theory. Full article ">Scheme 6
Gibbs free energy profiles (in kcal/mol) for the reaction of Z-i-C3F7C(O)NH2+TFAA+1Py calculated at the M06-2X/6-311++G(d,p) level of theory. Full article ">Scheme 7
Gibbs free energy profiles (in kcal/mol) for the reaction of i-C3F7C(O)NH2+TFAA+2Py calculated at the M06-2X/6-311++G(d,p) level of theory. Full article ">Scheme 8
Pyridine regeneration mechanism in the i-C3F7C(O)NH2+TFAA+2Py reaction at the M06-2X/6-311++G(d,p) level of theory. Full article ">

16 pages, 2048 KiB

Open AccessArticle

Castanea sativa Mill. By-Products: Investigation of Potential Anti-Inflammatory Effects in Human Intestinal Epithelial Cells

by Carola Pozzoli, Giulia Martinelli, Marco Fumagalli, Chiara Di Lorenzo, Nicole Maranta, Luca Colombo, Stefano Piazza, Mario Dell’Agli and Enrico Sangiovanni

Molecules 2024, 29(16), 3951; https://doi.org/10.3390/molecules29163951 - 21 Aug 2024

Viewed by 988

Abstract

Castanea sativa Mill. (C. sativa) processing and pruning generate several by-products, including leaves, burs, and shells (inner and outer teguments), which are considered an important source of high-value phytochemicals. Ellagitannins from C. sativa leaf extracts have been described to impair H. [...] Read more.

Castanea sativa Mill. (C. sativa) processing and pruning generate several by-products, including leaves, burs, and shells (inner and outer teguments), which are considered an important source of high-value phytochemicals. Ellagitannins from C. sativa leaf extracts have been described to impair H. pylori viability and inflammation in gastric cells. Furthermore, chestnut shells showed an important anti-inflammatory effect in gastric epithelial cells. Dietary polyphenols, including tannins, have been reported to interfere with targets of inflammation, including the nuclear factor κB (NF-κB). A promising role as a further therapeutical target for gut disorders has been recently proposed for the regulatory subunit of hypoxia-inducible factor (HIF-1α), as a potential stabilizer of intestinal barrier integrity. Therefore, the main objective of this work is the chemical characterization of several chestnut by-products (bud, spiny bur, wood, pericarp and episperm), together with the exploitation of their anti-inflammatory properties in intestinal cells, scavenging capacity, and stability following gastrointestinal digestion. The chemical characterization confirmed the presence of bioactive polyphenols in the extracts, including ellagitannins. In CaCo-2 cells stimulated by an IL-1β-IFN-γ cocktail, nearly all chestnut by-products (50 µg/mL) inhibited the release of proinflammatory mediators (CXCL-10, IL-8, MCP-1, ICAM), along with the NF-κB-driven transcription, and induced the HRE-driven transcription. The stability of the most promising extracts, identified through PCA and cluster analysis, was addressed by in vitro gastrointestinal digestion. Despite the significant reduction in total polyphenol index of chestnut bud and wood after gastric and intestinal digestion, the activity of these extracts on both scavenging and anti-inflammatory parameters remained promising. These data contribute to exploit the potential of chestnut by-products as sources of dietary polyphenols with anti-inflammatory properties at the intestinal level. Moreover, this study could represent an important step to encourage the recycling and valorization of chestnut by-products, promoting the circular economy and reducing the environmental impact related to the management of agriculture waste. Full article

(This article belongs to the Special Issue Advances in Functional Foods)

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Full article ">Figure 1
Effect of hydroalcoholic extracts from C. sativa by-products (50 µg/mL) on CXCL-10 (A), IL-8 (B), MCP-1 (C), ICAM-1 (D) release, measured by ELISA assay. Epigallocatechin-3-O-gallate (20 μM) was used as a reference inhibitor (positive control). Data (n = 3) are expressed as mean (%) ± SEM relative to IL-1β-IFN-γ, which was arbitrarily assigned the value of 100%. *** p < 0.001 vs. IL-1β-IFN-γ. Full article ">Figure 2
Effect of hydroalcoholic extracts from C. sativa by-products (50 µg/mL) on NF-κB- (A) and HRE (B)-driven transcriptions, measured by luciferase assay and reporter plasmids. DMOG (250 μM) was used as a reference compound for HIF induction (positive control) (A). Apigenin (20 μM) was used as reference inhibitor of the NF-κB activity (positive control). Data (n = 3) are expressed as mean (%) ± SEM relative to IL-1β -IFN-γ (A) or to control (B), which was arbitrarily assigned the value of 100%. * p < 0.05, *** p < 0.001 vs. IL-1β -IFN-γ (A) or Control (B). Full article ">Figure 3
Classification of chestnut by-products for inflammation (MCP-1, ICAM-1, CXCL-10, IL-8 release vs. stimulus; NF-κB-driven transcription vs. stimulus), antioxidant activity (ORAC and DPPH), total polyphenol index, ellagitannin content (vescalagin and castalagin), HRE-driven transcription (induction % vs. CTRL), based on PCA (A) and cluster analysis (B). Full article ">Figure 4
Effect of gastric or gastrointestinal digestion on total polyphenol index (mg gallic acid equivalent/g ± SE) and antioxidant activity (mmol Trolox equivalent/g ± SE) measured by DPPH assay on C. sativa bud and dry wood extract. Data (n = 3) are expressed as mean ± SEM. *** p < 0.001 vs. undigested extracts. Full article ">Figure 5
Effect of C. sativa bud (A) and dry wood (B) extracts after in vitro gastrointestinal digestion on CXCL-10 release, measured by ELISA assay. Epigallocatechin-3-O-gallate (20 μM) was used as reference inhibitor (positive control, in yellow). Data (n = 3) are expressed as mean (%) ± SEM related to IL-1β-IFN-γ, which was arbitrarily assigned the value of 100%. *** p < 0.001 vs. IL-1β-IFN-γ. Full article ">Figure A1
MTT assay performed on C. sativa by-product extracts (50 µg/mL) in CaCo-2 cells. Data (n = 3) are expressed as mean (%) ± SEM relative to control, which was arbitrarily assigned the value of 100%. Full article ">Figure A2
NRU assay performed on C. sativa by-product extracts (50 µg/mL) in CaCo-2. Data (n = 3) are expressed as mean (%) ± SEM relative to control, which was arbitrarily assigned the value of 100%. Full article ">

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