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Chemistry, Volume 6, Issue 6 (December 2024) – 27 articles

Cover Story (view full-size image): Diradical character is one of the characteristic quantities of functional open-shell molecules; now, we can use the diradical character as a powerful tool for molecular material designs. However, it is still unclear how the open-shell molecules are affected by the interaction with the surface. Our developed method, approximate spin-projected density functional theory with a plane-wave basis (AP-DFT/plane-wave), shows that (1) the diradical character is amplified by the orbital polarisation effects of oxide ions, and (2) the character decreases when the magnetic orbitals become electron-rich due to electron donation from the surfaces. The two effects are competing; the former is pronounced in Au systems, whereas the latter is pronounced in Ag systems. View this paper
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12 pages, 2993 KiB  
Technical Note
py.Aroma: An Intuitive Graphical User Interface for Diverse Aromaticity Analyses
by Zhe Wang
Chemistry 2024, 6(6), 1692-1703; https://doi.org/10.3390/chemistry6060103 - 23 Dec 2024
Cited by 5 | Viewed by 1815
Abstract
The nucleus-independent chemical shift (NICS) criterion plays a significant role in evaluating (anti-)aromaticity. While being readily accessible even for non-computational chemists, adding ghost atoms for multi-points NICS evaluations poses a significant challenge. In this article, I introduce py.Aroma 4, a freely available and [...] Read more.
The nucleus-independent chemical shift (NICS) criterion plays a significant role in evaluating (anti-)aromaticity. While being readily accessible even for non-computational chemists, adding ghost atoms for multi-points NICS evaluations poses a significant challenge. In this article, I introduce py.Aroma 4, a freely available and open-source Python package designed specifically for analyzing (anti-)aromaticity. Through its user-friendly graphical interface, py.Aroma simplifies and enhances aromaticity analyses by offering key features such as HOMA/HOMER index computation, Gaussian-type input file generation for diverse NICS calculations and corresponding output processing, NMR spectra plotting, and computational supporting information (SI) generation for scientific manuscripts. Additionally, NICS is suggested for evaluating (anti-)aromaticity for non-planar or tilted rings. Pre-compiled executables for macOS and Windows are freely available online. Facilitate accessibility for users lacking programming experience or time constraints. Full article
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12 pages, 1516 KiB  
Article
Compositional Dependence of DNA Partitioning in a Poly(Ethylene Glycol)–Ficoll Aqueous Two-Phase System
by Tasdiq Ahmed, Adya Verma, Alexandra T. Patterson, Mark P. Styczynski and Shuichi Takayama
Chemistry 2024, 6(6), 1680-1691; https://doi.org/10.3390/chemistry6060102 - 19 Dec 2024
Viewed by 1578
Abstract
Aqueous two-phase systems (ATPSs) have long been used for the facile and rapid extraction of biomolecules of interest. Selective partitioning of DNA is useful for nucleic acid purification and in the design of novel sensing technologies. This paper investigates the partitioning of a [...] Read more.
Aqueous two-phase systems (ATPSs) have long been used for the facile and rapid extraction of biomolecules of interest. Selective partitioning of DNA is useful for nucleic acid purification and in the design of novel sensing technologies. This paper investigates the partitioning of a plasmid within a poorly understood ATPS comprising the polymers poly(ethylene glycol) (PEG) 35 kDa and Ficoll 400 kDa. The focus is placed on dissecting the compositional effects of the ATPS—that is, whether set concentrations of physiological ions or the polymers themselves can tune DNA phase preference and strength of partitioning. The work here uncovers the antagonistic effects of magnesium and ammonium ions, as well as the role that phase-forming polymer partitioning plays in plasmid enrichment. Testing the ions in conjunction with different ATPS formulations highlights the complexity of the system at hand, prompting the exploration of DNA’s conformational changes in response to polymer and salt presence. The work presented here offers multiple optimization parameters for downstream applications of PEG–Ficoll ATPSs, such as in vitro transcription/translation-based biosensing, in which performance is heavily dependent upon nucleic acid partitioning. Full article
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22 pages, 7063 KiB  
Article
Sulfide, Sulfoxide, and Sulfone Derivatives of Usnic Acid as Inhibitors of Human TDP1 and TDP2 Enzymes
by Aleksandr S. Filimonov, Marina A. Mikhailova, Nadezhda S. Dyrkheeva, Irina A. Chernyshova, Tatyana E. Kornienko, Konstantin A. Naumenko, Rashid O. Anarbaev, Andrey A. Nefedov, Chigozie Achara, Anthony D. M. Curtis, Olga A. Luzina, Konstantin P. Volcho, Nariman F. Salakhutdinov, Olga I. Lavrik and Jóhannes Reynisson
Chemistry 2024, 6(6), 1658-1679; https://doi.org/10.3390/chemistry6060101 - 17 Dec 2024
Viewed by 1279
Abstract
Tyrosyl-DNA phosphodiesterases 1 and 2 (TDP1 and TDP2) are important DNA repair enzymes that remove various adducts from the 3′- and 5′-ends of DNA, respectively. The suppression of the activity of these enzymes is considered as a promising adjuvant therapy for oncological diseases [...] Read more.
Tyrosyl-DNA phosphodiesterases 1 and 2 (TDP1 and TDP2) are important DNA repair enzymes that remove various adducts from the 3′- and 5′-ends of DNA, respectively. The suppression of the activity of these enzymes is considered as a promising adjuvant therapy for oncological diseases in combination with topoisomerase inhibitors. The simultaneous inhibition of TDP1 and TDP2 may result in greater antitumor effects, as these enzymes can mimic each other’s functions. We have previously shown that usnic acid-based sulfides can act as dual inhibitors, with TDP1 activity in the low micromolar range and their TDP2 at 1 mM. The oxidation of their sulfide moieties to sulfoxides led to an order of magnitude decrease in their cytotoxicity potential, while their TDP1 and TDP2 activity was preserved. In this work, we synthesized new series of usnic acid-based sulfides and their oxidized analogues, i.e., sulfoxides and sulfones, to systematically study these irregularities. The new compounds inhibit TDP1 with IC50 values (the concentration of inhibitor required to reduce enzyme activity by half) in the 0.33–25 μM range. Most sulfides and some sulfoxides and sulfones inhibit TDP2 with an IC50 = 138−421 μM. In addition, the most active compounds synergized (×4) with topotecan on the HeLa cell line as well as causing dose-dependent DNA damage, as confirmed by Comet assay. Sulfides with the 6-methylbenzoimidazol-2-yl substituent (8f, IC50 = 0.33/138 μM, TDP1/2) and sulfones containing a pyridine-2-yl fragment (12k, IC50 = 2/228 μM, TDP1/2) are the most potent derivatives and, therefore, are promising for further development. Full article
(This article belongs to the Topic Enzymes and Enzyme Inhibitors in Drug Research)
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13 pages, 1984 KiB  
Article
A Novel Galantamine–Curcumin Hybrid Inhibits Butyrylcholinesterase: A Molecular Dynamics Study
by Evdokiya Salamanova, Mariyana Atanasova and Irini Doytchinova
Chemistry 2024, 6(6), 1645-1657; https://doi.org/10.3390/chemistry6060100 - 16 Dec 2024
Cited by 1 | Viewed by 1282
Abstract
Cholinesterases are enzymes that break down the neurotransmitter acetylcholine in the nervous system. The two main types are acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). AChE inhibitors are used to treat Alzheimer’s disease by increasing acetylcholine levels. BChE activity increases in later stages of Alzheimer’s, [...] Read more.
Cholinesterases are enzymes that break down the neurotransmitter acetylcholine in the nervous system. The two main types are acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). AChE inhibitors are used to treat Alzheimer’s disease by increasing acetylcholine levels. BChE activity increases in later stages of Alzheimer’s, suggesting it might contribute to the disease. In previous experiments, it was found that a newly designed hybrid of galantamine (GAL) and curcumin (CCN) (compound 4b) decreases the activity of BChE in murine brain homogenates. Here, we explore this observation using molecular dynamics simulations. GAL and CCN were also studied for comparison. The structures of the complexes between the BChE and the ligands were predicted by molecular docking. Then, molecular dynamics simulations were performed to evaluate the stability of the complexes and the interactions between the ligands and the enzyme over a simulated time of 1 μs. All three ligands formed stable complexes with BChE. Compound 4b formed more hydrogen bonds and other interactions with BChE compared to GAL and CCN, suggesting a stronger binding affinity. The stronger binding of 4b to BChE might explain its superior anti-BChE activity observed in previous experiments. Full article
(This article belongs to the Section Theoretical and Computational Chemistry)
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10 pages, 1488 KiB  
Communication
Alkoxy Substituted Brominated closo-Dodecaborates with Functionalized Aliphatic Spacers
by Satoshi Yamamoto, Hibiki Nakamura, Yumiko K. Kawamura, Taro Kitazawa, Mutsumi Kimura and Yu Kitazawa
Chemistry 2024, 6(6), 1635-1644; https://doi.org/10.3390/chemistry6060099 - 15 Dec 2024
Viewed by 1289
Abstract
The utilization of dodecaborate boron clusters, [B12X12]2− (X = Cl, Br, or I), as membrane carriers has been demonstrated recently, and their activity is known to be due to their superchaotropic nature. In this work, the mono-alkylation of [...] Read more.
The utilization of dodecaborate boron clusters, [B12X12]2− (X = Cl, Br, or I), as membrane carriers has been demonstrated recently, and their activity is known to be due to their superchaotropic nature. In this work, the mono-alkylation of [B12Br11OH]2− to functionalize it with an aliphatic spacer was developed with a view to expanding the known chemical space of membrane carriers based on [B12Br12]2−. A new and improved facile route for the preparation of [B12Br11OH]2−, which is an important precursor to other [B12Br11OR]2− species, is reported. Various alkoxylated [B12Br11O(CH2)5Z]2− (Z = OH, N(CO)2C6H4, CN and N3) derivatives were prepared via a divergent synthesis based on [B12Br11O(CH2)5Br]2−. One of the newly synthesized compounds was utilized as a membrane carrier, and its impact on cell viability was examined. Full article
(This article belongs to the Section Molecular Organics)
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13 pages, 5221 KiB  
Article
Efficient Catalytic Hydrogenation of Lignin-Derived Phenolics Under Mild Conditions
by Yumeng Song, Ping Chen, Hui Lou, Xiaoming Zheng and Xiangen Song
Chemistry 2024, 6(6), 1622-1634; https://doi.org/10.3390/chemistry6060098 - 12 Dec 2024
Viewed by 1150
Abstract
This paper studies the catalytic hydrogenation reduction of lignin-derived phenolic compounds, such as catechol, guaiacol (O-methoxyphenol), phenol, P-methylphenol, O-ethylphenol, O-ethoxyphenol, etc. The reaction system focuses on the catalytic performance of hydrodeoxygenation reactions involving the phenolic derivatives of the lignin depolymerization products catechol and [...] Read more.
This paper studies the catalytic hydrogenation reduction of lignin-derived phenolic compounds, such as catechol, guaiacol (O-methoxyphenol), phenol, P-methylphenol, O-ethylphenol, O-ethoxyphenol, etc. The reaction system focuses on the catalytic performance of hydrodeoxygenation reactions involving the phenolic derivatives of the lignin depolymerization products catechol and guaiacol. A series of Al2O3-TiO2 composite oxide supports with different Al/Ti ratios were prepared by a co-precipitation method, and a 5% Pd/Al2O3-TiO2 bifunctional catalyst was prepared by an impregnation method and characterized with XRD, SEM, BET, NH3-TPD, etc. Among these, the Pd/Al2Ti1 catalyst had the most excellent catalytic performance. At 100 °C and 2 MPa hydrogen pressure, the conversion of catechol was as high as 100%, and at 100 °C and 5 MPa hydrogen pressure, the conversion of guaiacol reached 90%. Full article
(This article belongs to the Section Catalysis)
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14 pages, 2549 KiB  
Article
8-(Pyridin-2-yl)quinolin-7-ol and Beyond: Theoretical Design of Tautomeric Molecular Switches with Pyridine as a Proton Crane Unit
by Lidia Zaharieva, Daniela Nedeltcheva-Antonova and Liudmil Antonov
Chemistry 2024, 6(6), 1608-1621; https://doi.org/10.3390/chemistry6060097 - 6 Dec 2024
Cited by 2 | Viewed by 1456
Abstract
Long-range proton transfer in several conjugated proton cranes, originating from 7-hydroxy quinoline as a proton transfer platform, has been investigated theoretically by means of DFT and TD-DFT methodology. Major emphasis was given to their applicability to provide clean switching upon irradiation. The border [...] Read more.
Long-range proton transfer in several conjugated proton cranes, originating from 7-hydroxy quinoline as a proton transfer platform, has been investigated theoretically by means of DFT and TD-DFT methodology. Major emphasis was given to their applicability to provide clean switching upon irradiation. The border conditions require the existence of a single enol tautomer in the ground state, which under excitation through a series of consecutive exited and ground state intramolecular proton transfer steps is transferred to the keto tautomer. It was shown that the most suitable candidates are based on using iso-quinoline, pyrimidine and 4-nitropyridine as proton crane units. Their suitability is a function of aromaticity changes, the basicity of the nitrogen atom from the proton crane unit and the structural effects originating from their conjugation with 7-hydroxy quinoline. Full article
(This article belongs to the Section Physical Chemistry and Chemical Physics)
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15 pages, 2466 KiB  
Article
DFT Investigation of the Mechanism of Methoxycarbonylation of Styrene by Palladium Chloride
by Shanti Gopal Patra, Aritra Saha and Pratim Kumar Chattaraj
Chemistry 2024, 6(6), 1593-1607; https://doi.org/10.3390/chemistry6060096 - 5 Dec 2024
Viewed by 2475
Abstract
The alkoxycarbonylation of styrene by palladium chloride is studied employing the density functional theory (DFT). Initially, [PdCl3] reacts with methanol to form the methoxy-bound intermediate, which undergoes β-hydride elimination to form the key intermediate [PdCl2H]. [...] Read more.
The alkoxycarbonylation of styrene by palladium chloride is studied employing the density functional theory (DFT). Initially, [PdCl3] reacts with methanol to form the methoxy-bound intermediate, which undergoes β-hydride elimination to form the key intermediate [PdCl2H]. Then, a 1,2-insertion reaction to styrene takes place to form linear and branched alkyl coordinated with the PdII. Then, CO coordination followed by a 1,1-insertion reaction leads to the formation of acyl intermediate. Next, the methanolysis leads to the formation of esters. Previous reports with other catalysts suggested the intermolecular/intramolecular transition state (TS) formation with a high activation barrier, and this step was the bottleneck. To the best of our knowledge, this is the first time we have considered a two-step mechanism for the alcoholysis of the ester formation mechanism. After coordination with the metal, the methanol undergoes oxidative addition to form the PdIV square pyramidal intermediate, followed by reductive elimination to form the ester with regeneration of the metal hydride active intermediate. Deeper insight into the nature of bonding at the TSs is obtained through energy decomposition with natural orbital for chemical valence (EDA-NOCV) and quantum theory of atoms in molecules (QTAIM). Full article
(This article belongs to the Section Theoretical and Computational Chemistry)
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21 pages, 6552 KiB  
Article
Systematic Investigation on Surface Diradicals Using Theoretical Models: 2M/MgO and 2M/BaO (M = Cu, Ag, and Au)
by Kohei Tada, Koki Masuda, Ryohei Kishi and Yasutaka Kitagawa
Chemistry 2024, 6(6), 1572-1592; https://doi.org/10.3390/chemistry6060095 - 5 Dec 2024
Cited by 1 | Viewed by 1325
Abstract
Diradical character is one of the characteristic quantities of functional open-shell molecules. Prof. Nakano devotedly studied the relationship between diradical character and material properties of open-shell molecules; now, we can use the diradical character as a powerful tool for molecular material designs. It [...] Read more.
Diradical character is one of the characteristic quantities of functional open-shell molecules. Prof. Nakano devotedly studied the relationship between diradical character and material properties of open-shell molecules; now, we can use the diradical character as a powerful tool for molecular material designs. It is still unclear how the open-shell molecules are affected by the interaction with the surface although the molecules have been immobilised for device applications. In the present study, the adsorptions of model diradical molecules with s-electrons on the MgO (001) and BaO (001) surfaces are investigated using approximate spin projected density functional theory with plane-wave basis (AP-DFT/plane-wave) to provide a systematic discussion of surface–diradical interactions. The accuracy of AP-DFT/plane-wave was verified by comparisons with the calculated results by NEVPT2. The computational error introduced by DFT calculations on the diradical state (spin contamination error) is reduced by the surface–diradical interaction. In addition, it is shown that (1) the diradical character is amplified by the orbital polarisation effects of oxide ions, and (2) the character decreases when the magnetic orbitals become electron-rich due to electron donation from the surfaces. The two effects are competing; the former is pronounced in Au systems, whereas the latter is pronounced in Ag systems. Full article
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20 pages, 2372 KiB  
Article
Rapid and Accurate Prediction of the Melting Point for Imidazolium-Based Ionic Liquids by Artificial Neural Network
by Xinyu Liu, Jie Yin, Xinmiao Zhang, Wenxiang Qiu, Wei Jiang, Ming Zhang, Linhua Zhu, Hongping Li and Huaming Li
Chemistry 2024, 6(6), 1552-1571; https://doi.org/10.3390/chemistry6060094 - 30 Nov 2024
Cited by 1 | Viewed by 1665
Abstract
Imidazolium-based ionic liquids (ILs) have been regarded as green solvents owing to their unique properties. Among these, the melting point is key to their excellent performance in applications such as catalysis, biomass processing, and energy storage, where stability and operational temperature range are [...] Read more.
Imidazolium-based ionic liquids (ILs) have been regarded as green solvents owing to their unique properties. Among these, the melting point is key to their excellent performance in applications such as catalysis, biomass processing, and energy storage, where stability and operational temperature range are critical. The utilization of neural networks for forecasting the melting point is highly significant. Nevertheless, the excessive selection of descriptors obtained by density functional theory (DFT) calculations always leads to huge computational costs. Herein, this study strategically selected only 12 kinds of quantum chemical descriptors by employing a much more efficient semi-empirical method (PM7) to reduce computational costs. Four principles of data pre-processing were proposed, and the innovative use of a simulated annealing algorithm to search for the lowest energy molecular conformation improved accuracy. Based on these descriptors, a multi-layer perceptron neural network model was constructed to efficiently predict the melting points of 280 imidazolium-based ILs. The R2 value of the current model reached 0.75, and the mean absolute error reached 25.03 K, indicating that this study achieved high accuracy with very little computational cost. This study reveals a strong correlation between descriptors and melting points. Additionally, the model accurately predicts unknown melting points of imidazolium-based ILs, achieving good results efficiently. Full article
(This article belongs to the Section Theoretical and Computational Chemistry)
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17 pages, 2186 KiB  
Article
Phenolic Constituents from Hypericum aucheri Jaub et. Spach—Isolation, Identification, and Preliminary Evaluation for hMAO-A/B and Neuroprotective Activity
by Teodor Marinov, Magdalena Kondeva-Burdina, Zlatina Kokanova-Nedialkova and Paraskev T. Nedialkov
Chemistry 2024, 6(6), 1535-1551; https://doi.org/10.3390/chemistry6060093 - 30 Nov 2024
Viewed by 934
Abstract
Three new acylated benzophenone O-glycosides named aucherosides A–C (46), together with five known compounds such as mangiferin (1), maclurin-6-O-β-D-glucopyranoside (2), 1-O-galloyl-β-D-glucose (3), vanillic acid (7), and 5-hydroxy-2-isopropylchromone-7-O-β-glucoside (8), were [...] Read more.
Three new acylated benzophenone O-glycosides named aucherosides A–C (46), together with five known compounds such as mangiferin (1), maclurin-6-O-β-D-glucopyranoside (2), 1-O-galloyl-β-D-glucose (3), vanillic acid (7), and 5-hydroxy-2-isopropylchromone-7-O-β-glucoside (8), were isolated from the aerial parts of Hypericum aucheri Jaub. and Spach and identified with spectroscopic methods (1D and 2D NMR, and HRESIMS). Compounds 2, 46, 8, and previously isolated from the title plant aucherines A–C (911), were tested for hMAO-A and B inhibitory effects and neuroprotection. All tested compounds (1 µM) did not exhibit any inhibitory effect on hMAO-A and showed significant inhibitory activity against the hMAO-B enzyme. Notably, compound 8 demonstrated the strongest hMAO-B inhibition, approaching that of the positive control selegiline. At high concentrations (100 µM), all tested compounds showed no neurotoxic or pro-oxidant effects on rat brain synaptosomes, mitochondria, and microsomes. All tested compounds exhibited good neuroprotective and antioxidant activities in various neurotoxicity models (6-hydroxydopamine-induced neurotoxicity on synaptosomes, tert-butyl hydroperoxide-induced oxidative stress on mitochondria, and non-enzymatic lipid peroxidation on microsomes). The neuroprotective mechanisms of these compounds may include MAO-B inhibition, reactive oxygen species (ROS) scavenging, membrane stabilization, and preservation of reduced glutathione (GSH), the primary nucleophilic ROS scavenger. Full article
(This article belongs to the Section Biological and Natural Products)
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12 pages, 4340 KiB  
Article
A New Hydrotalcite-Like Absorbent OSA-LDH and Its Adsorption Capacity for Pb2+ Ions in Water
by Zong-Lai Liu, Hao Yu, Ya-Nan Chen and Wei Feng
Chemistry 2024, 6(6), 1523-1534; https://doi.org/10.3390/chemistry6060092 - 30 Nov 2024
Viewed by 1119
Abstract
Hydrotalcite-like materials (OSA-LDH) were prepared used oil shale ash (OSA), which came from a thermal power plant area, as the main raw material. The characterization results of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and thermogravimetric-differential scanning calorimetry (TG-DSC) [...] Read more.
Hydrotalcite-like materials (OSA-LDH) were prepared used oil shale ash (OSA), which came from a thermal power plant area, as the main raw material. The characterization results of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and thermogravimetric-differential scanning calorimetry (TG-DSC) showed that the prepared samples were mesoporous materials in a crystal state and were layered and contained lattice oxygen and a large number of surface hydroxyl groups. The adsorption property of the prepared samples was confirmed and evaluated by adsorption experiments with Pb2+ as the target pollutant. The adsorption process was in accord with the Langmuir isothermal adsorption equation, and the adsorption data fitted perfectly with the pseudo-second kinetic equation. The saturated adsorption capacity for Pb2+ was 120.92 mg·g−1 at a temperature of 298 K and initial concentration of 300 mg·L−1. The main adsorption mechanisms of OSA-LDH for Pb2+ were chemical bond cooperation and electrostatic bond cooperation. This paper aimed to not only prepare an economical and effective adsorbent to remove heavy metal ions from the solution but also provide a new path for the treatment and utilization of OSA so as to realize efficient waste resource utilization. Full article
(This article belongs to the Section Green and Environmental Chemistry)
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14 pages, 3223 KiB  
Article
Molecular Conductors Based on Dimethylcyclohexene-Fused Tetrathiafulvalene
by Masahiro Fujisaki, Ryoya Naito, Takashi Shirahata, Yoshitaka Kawasugi, Naoya Tajima and Yohji Misaki
Chemistry 2024, 6(6), 1509-1522; https://doi.org/10.3390/chemistry6060091 - 25 Nov 2024
Viewed by 1236
Abstract
Chiral electroactive materials have attracted attention for the effects of electrical magnetochiral anisotropy (eMChA) and chirality-induced spin selectivity (CISS). The combination of tetrathiafulvalene (TTF) with chiral moieties is one way to access chiral electroactive materials. In this paper, we have focused on the [...] Read more.
Chiral electroactive materials have attracted attention for the effects of electrical magnetochiral anisotropy (eMChA) and chirality-induced spin selectivity (CISS). The combination of tetrathiafulvalene (TTF) with chiral moieties is one way to access chiral electroactive materials. In this paper, we have focused on the fused 2,3-dimethylcyclohexene (DMCh) ring as a substituent with chiral carbon atoms and without heteroatoms, which has not been used in the field of molecular conductors, and we synthesized a new TTF derivative (rac-DMCh-EDT-TTF). We have developed novel molecular conductors (rac-DMCh-EDT-TTF)2X (X = PF6, AsF6 and ClO4), which have bilayer conducting sheets composed of the two crystallographically independent molecules. All salts exhibited semiconducting behavior from room temperature down to low temperatures, and a resistivity anomaly was observed at 180–250 K. X-ray structure analysis at 100 K and 263 K and molecular orbital calculations using the results of X-ray structure analysis indicated the emergence of a charge disproportionation between Layers 1 and 2 at the low-temperature phase. Full article
(This article belongs to the Section Inorganic and Solid State Chemistry)
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14 pages, 2813 KiB  
Review
Emerging Trends in Skin Anti-Photoaging by Lactic Acid Bacteria: A Focus on Postbiotics
by Xiangji Jin, Trang Thi Minh Nguyen, Eun-Ji Yi, Qiwen Zheng, Se-Jig Park, Gyeong-Seon Yi, Su-Jin Yang, Mi-Ju Kim and Tae-Hoo Yi
Chemistry 2024, 6(6), 1495-1508; https://doi.org/10.3390/chemistry6060090 - 22 Nov 2024
Cited by 1 | Viewed by 2055
Abstract
Background: Reflecting the increasing interest and research on living a healthy life as society ages, there has been a surge in attention and studies on photodamage. Probiotics have been studied for their ability to enhance skin integrity and provide protection from ultraviolet radiation [...] Read more.
Background: Reflecting the increasing interest and research on living a healthy life as society ages, there has been a surge in attention and studies on photodamage. Probiotics have been studied for their ability to enhance skin integrity and provide protection from ultraviolet radiation (UVR). However, despite this, extensive research has revealed various issues and side effects, prompting increased interest in alternative options that can effectively and safely protect the skin. We focused on postbiotics as a promising solution for photodamage, aiming to demonstrate their potential as a safe and stable alternative to probiotics. Methods: We investigated papers on “skin aging” or “photoaging” and “probiotics” or “postbiotics” from 2013 to 2023 using the Web of Science, PubMed, and Scopus. Additionally, we compared and analyzed publications, authors, countries, keywords, and citations using the VOS viewer program. Results: According to our search results, the majority of papers on photodamage and probiotics were published in PubMed, with the United States leading in publication volume among countries. The most common keywords were “photodamage” and “skin”. The most cited paper recorded 470 citations. Furthermore, upon focused analysis of five papers on postbiotics and photodamage, postbiotics demonstrated preventive and protective effects against skin photodamage. Conclusions: Postbiotics for photodamage show potential as a safe and stable alternative to probiotics. However, research on postbiotics and photodamage remains limited, and additional studies and long-term tracking are essential to substantiate our claims. Full article
(This article belongs to the Section Biological and Natural Products)
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18 pages, 6103 KiB  
Article
Extended Chalcones: Synthesis, In Vitro Analysis, and In Vivo Testing Against a Drosophila melanogaster Alzheimer’s Disease Model
by Aadya Jaipuria, Madison Castillo, James Boksanski, Greg Landry, Ji Hyung Beak, Michelle Young, David T. Priefer, Kaïs Guessab, Crystal N. Ellis and Ronny Priefer
Chemistry 2024, 6(6), 1477-1494; https://doi.org/10.3390/chemistry6060089 - 22 Nov 2024
Viewed by 1474
Abstract
Alzheimer’s Disease (AD) is the most common form of dementia in individuals over the age of 65. There is no known prevention for the progression of the disease, although the FDA recently approved two drugs for AD. The exact etiology of AD is [...] Read more.
Alzheimer’s Disease (AD) is the most common form of dementia in individuals over the age of 65. There is no known prevention for the progression of the disease, although the FDA recently approved two drugs for AD. The exact etiology of AD is still under debate; however, it is commonly associated with the aggregation of amyloid-beta (Aβ) plaques in the brain. Recently some extended chalcones were reported to be potential anti-amyloidogenic agents. In this study, a larger library of extended chalcone analogs were synthesized with modifications on both rings. These were tested using the Thioflavin T fluorescence assay to measure their anti-Aβ aggregation properties. Three notably active compounds were further evaluated for potential neurotoxicity and neuroprotection using an MTT cell viability assay. These compounds were non-neurotoxic and displayed a trend toward neuroprotection. These were further assessed in a Drosophila melanogaster animal AD model. A forced climbing assay revealed statistically significant changes in flies’ movement by ~30% when fed these anti-amyloidogenic agents. Full article
(This article belongs to the Section Medicinal Chemistry)
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19 pages, 45939 KiB  
Article
Design and Rapid Prototyping of 3D-Printed Microfluidic Systems for Multiphase Flow
by Bastian Oldach, Robin Fortmann, Theo Pleie, Philip Timm and Norbert Kockmann
Chemistry 2024, 6(6), 1458-1476; https://doi.org/10.3390/chemistry6060088 - 21 Nov 2024
Cited by 1 | Viewed by 1934
Abstract
Since the emergence of microfluidic devices, subtractive manufacturing techniques have dominated their production. Although the conventional manufacturing processes are well established, they come along with some disadvantages that limit the accessibility and hinder the further development of microfluidics. With the rise of additive [...] Read more.
Since the emergence of microfluidic devices, subtractive manufacturing techniques have dominated their production. Although the conventional manufacturing processes are well established, they come along with some disadvantages that limit the accessibility and hinder the further development of microfluidics. With the rise of additive manufacturing, researchers are focused on developing alternative fabrication methods to promote affordability and accessibility. This paper presents the opportunities and challenges of laser-based stereolithography printers for the fabrication of microfluidic equipment. Emphasis is put on the design and iterative prototyping process from the initial design idea to the final device. To print with adequate and sufficient geometrical accuracy and suitable material, the optimization of the printer’s performance is discussed. Regarding the design of multiphase microfluidics and its complex fluid behavior, suitable surface treatments, including an appropriate cleaning protocol, and coating strategies to make the printed channels either hydrophilic or hydrophobic are presented to ensure applicability. With these fundamentals of additive manufacturing in microfluidic fabrication at hand, the second focus of this contribution is on the application of a modular co-flow device and a monolithic flow-focusing device to generate droplets and slugs in different multiphase flow applications. The presented co-flow setup features a tapered capillary that affects the droplet and slug sizes due to differing diameters, with larger diameters leading to larger droplets and slugs and vice versa. Several design parameters for the flow-focusing device were evaluated to determine the influence of device design on multiphase flow formation. It was found that the diameter of the inlet for the dispersed phase has the greatest effect on the size of the resulting droplets and slugs and covers the largest range of adjustable sizes. Full article
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9 pages, 1577 KiB  
Communication
Addition of a Perfluoroalkyl Acetyl Group to the C-Vertex of a Carborane Anion to Enhance Its Solubility in Fluorinated Ether Solvents
by Sota Iwashita, Mutsumi Kimura and Yu Kitazawa
Chemistry 2024, 6(6), 1449-1457; https://doi.org/10.3390/chemistry6060087 - 18 Nov 2024
Viewed by 918
Abstract
The modification of carborane anion monocarba-closo-dodecaborate (1) with perfluoroalkyl groups enhances its solubility in fluorinated ethers. This novel approach achieves a degree of solubility that is unattainable by using traditional lipophilic modifications or boro–vertex functionalizations of 1. A [...] Read more.
The modification of carborane anion monocarba-closo-dodecaborate (1) with perfluoroalkyl groups enhances its solubility in fluorinated ethers. This novel approach achieves a degree of solubility that is unattainable by using traditional lipophilic modifications or boro–vertex functionalizations of 1. A spectroscopic analysis in combination with DFT calculations confirmed that these new anions retain their weakly coordinating nature and exhibit moderate chemical stability. Full article
(This article belongs to the Section Molecular Organics)
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10 pages, 5129 KiB  
Commentary
Challenging the Chemistry of Climate Change
by Bruce Peachey and Nobuo Maeda
Chemistry 2024, 6(6), 1439-1448; https://doi.org/10.3390/chemistry6060086 - 16 Nov 2024
Cited by 2 | Viewed by 5911
Abstract
As talk grows about billions or even trillions of dollars being directed toward potential “Net Zero” activities, it is imperative that the chemistry inherent in or driving those actions make scientific sense. The challenge is to close the mass and energy balances to [...] Read more.
As talk grows about billions or even trillions of dollars being directed toward potential “Net Zero” activities, it is imperative that the chemistry inherent in or driving those actions make scientific sense. The challenge is to close the mass and energy balances to the carbon and oxygen cycles in the Earth’s atmosphere and oceans. Several areas of climate science have been identified that chemists can investigate through methods that do not require a supercomputer or a climate model for investigation, most notably the following: (1) The carbon cycle, which still needs to be balanced, as many known streams, such as carbon to landfills, carbon in human-enhanced sewage and land runoff streams, and carbon stored in homes and other material, do not seem to have been accounted for in carbon balances used by the IPCC. (2) Ocean chemistry and balances are required to explain the causes of regional and local-scale salinity, pH, and anoxic conditions vs. global changes. For example, local anoxic conditions are known to be impacted by changes in nutrient discharges to oceans, while large-scale human diversions of fresh water streams for irrigation, power, and industrial cooling must have regional impacts on oceanic salinity and pH. (3) Carbon Capture and Storage (CCS) schemes, if adopted on the large scales being proposed (100s to 1000s of Gt net injection by 2100), should impact the composition of the atmosphere by reducing free oxygen, adding more water from combustion, and displacing saline water from subsurface aquifers. Data indicate that atmospheric oxygen is currently dropping at about twice the rate of CO2 concentrations increasing, which is consistent with combustion chemistry with 1.5 to 2 molecules of oxygen being converted through combustion to 1 molecule of CO2 and 1 to 2 molecules of H2O, with reverse reactions occurring as a result of oxygenic photosynthesis by increased plant growth. The CCS schemes will sabotage these reverse reactions of oxygenic photosynthesis by permanently sequestering the oxygen atoms in each CO2 molecule. Full article
(This article belongs to the Section Physical Chemistry and Chemical Physics)
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12 pages, 1933 KiB  
Article
Theoretical Study on One- and Two-Photon Absorption Properties of π-Stacked Multimer Models of Phenalenyl Radicals
by Masako Yokoyama, Ryohei Kishi and Yasutaka Kitagawa
Chemistry 2024, 6(6), 1427-1438; https://doi.org/10.3390/chemistry6060085 - 14 Nov 2024
Viewed by 1391
Abstract
Effects of the number of monomers (N) on the two-photon absorption (TPA) properties of π-stacked multimer models consisting of phenalenyl radicals were investigated theoretically. We conducted spectral simulations for the π-stacked N-mer models (N = 2, 4, and 6) [...] Read more.
Effects of the number of monomers (N) on the two-photon absorption (TPA) properties of π-stacked multimer models consisting of phenalenyl radicals were investigated theoretically. We conducted spectral simulations for the π-stacked N-mer models (N = 2, 4, and 6) with different stacking distances (d1) and their alternation patterns (d2/d1). Excitation energies and transition dipole moments were calculated at the extended multi-configurational quasi-degenerate second-order perturbation theory (XMC-QDPT2) level based on the complete active space self-consistent field (CASSCF) wavefunctions with the active space orbitals constructed from the singly occupied molecular orbitals (SOMOs) of monomers. The TPA cross-section value per dimer unit at the first peak, originating from the electronic transition along the stacking direction, was predicted to increase significantly as the d2/d1 approaches one, as the d1 decreases, and as the N increases from 2 to 6. These tendencies are similar to the calculation results for the static hyperpolarizabilities. Full article
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12 pages, 2868 KiB  
Article
Dynamic Magnetic Control of Lanthanide Metal–Organic Framework Crystals and Their Polarized Emissions
by Bojun Shi, Hao Jia, Lingfang Chen, Shuchun Zhang, Yu Zhang, Baipeng Yin, Shuming Bai and Chuang Zhang
Chemistry 2024, 6(6), 1415-1426; https://doi.org/10.3390/chemistry6060084 - 14 Nov 2024
Viewed by 1243
Abstract
Traditional barcode encoding methods are constrained by the inability to dynamically control crystal orientations, thereby limiting their applications. In this work, we investigate the dynamic magnetic control of lanthanide metal–organic framework crystals and their potential for advancing photonic barcode technology. A paramagnetic fluorescent [...] Read more.
Traditional barcode encoding methods are constrained by the inability to dynamically control crystal orientations, thereby limiting their applications. In this work, we investigate the dynamic magnetic control of lanthanide metal–organic framework crystals and their potential for advancing photonic barcode technology. A paramagnetic fluorescent Eu-MOF microcrystal with sizes ranging from 30 to 40 μm in length and 5 to 10 μm in width was synthesized, and its magnetic orientation and polarized emission were systematically investigated. Eu-MOF crystallizes in an orthorhombic space group, growing along the crystallographic b-axis and ultimately forming an anisotropic cuboid shape. Eu-MOF microcrystals exhibit significant magnetic anisotropy, causing the crystallographic c-axis of the crystal to align with the magnetic field when a uniaxial magnetic field of ~10 mT is applied. Furthermore, the Eu-MOF microcrystal exhibited characteristic Eu emissions with peaks at 594 nm, 616 nm, and 695 nm, and showed a high degree of polarization (DOP), reaching 0.904 at 616 nm. Therefore, the utilization of a rotating magnetic field not only enables precise and dynamic control over the crystal orientations but also results in a significant variation in the luminescence intensity. This capability enabled us to propose an innovative encryption barcode scheme in which the emission intensities of different luminescence peaks are converted into barcode widths, with the sequence of magnetic field directions serving as the encryption key. This approach presents a novel method for data storage and anti-counterfeiting, significantly enhancing the versatility and capacity of photonic barcodes. Full article
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19 pages, 2581 KiB  
Article
Design, Synthesis, and Evaluation of EA-Sulfonamides and Indazole-Sulfonamides as Promising Anticancer Agents: Molecular Docking, ADME Prediction, and Molecular Dynamics Simulations
by Nassima Saghdani, Nabil El Brahmi, Abdelmoula El Abbouchi, Rachid Haloui, Souad Elkhattabi, Gérald Guillaumet and Saïd El Kazzouli
Chemistry 2024, 6(6), 1396-1414; https://doi.org/10.3390/chemistry6060083 - 9 Nov 2024
Cited by 3 | Viewed by 2419
Abstract
New EA-sulfonamides and indazole-sulfonamides were synthesized, characterized, and evaluated for their anticancer activities. The target compound structures were elucidated using various spectroscopic techniques such as NMR-{1H and 13C}, infrared spectroscopy, and high-resolution mass spectrometry. The anticancer activities of the [...] Read more.
New EA-sulfonamides and indazole-sulfonamides were synthesized, characterized, and evaluated for their anticancer activities. The target compound structures were elucidated using various spectroscopic techniques such as NMR-{1H and 13C}, infrared spectroscopy, and high-resolution mass spectrometry. The anticancer activities of the novel compounds were evaluated against four human cancer cell lines, namely A-549, MCF-7, Hs-683, and SK-MEL-28 as well as the normal cell line HaCaT, using 5-fluorouracil and etoposide as reference drugs. Among the tested compounds, 9, 10, and 13 exhibited potent anticancer activities which are better than or similar to the reference compounds 5-fluorouracil and etoposide, against the A-549, MCF-7, and Hs-683 cancer cell lines, with IC50 values ranging from 0.1 to 1 μM. Molecular docking studies of compounds 9, 10, and 13 showed a strong binding with selected protein kinase targets, which are linked to the tested cancer types. Furthermore, the analysis of the molecular dynamics simulation results demonstrated that compound 9 exhibits significant stability when bound to both JAK3 and ROCK1 kinases. This new compound has the potential to be developed as a novel therapeutic agent against various cancers. Full article
(This article belongs to the Special Issue Cutting-Edge Studies of Computational Approaches in Drug Discovery)
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11 pages, 1263 KiB  
Article
Thermal Decomposition of Compounds Derived from 2H-Dihydropyran: A Computational Study
by Pablo Ruiz, Sara Bucheli, Paula Fernández, Silvia Quijano, Jairo Quijano and Jair Gaviria
Chemistry 2024, 6(6), 1385-1395; https://doi.org/10.3390/chemistry6060082 - 7 Nov 2024
Viewed by 1593
Abstract
This research study computationally examined the thermal decomposition of three molecules, 3,6-dihydro-2H-pyran, 4-methyl-3,6-dihydro-2H-pyran, and 2,6-dimethyl-3,6-dihydro-2H-pyran, using the PBE0/6-311+G(d,p) level of theory and a concerted mechanism with a 6-member cyclic transition state. For this analysis, kinetic and thermodynamic parameters were calculated for reactions within [...] Read more.
This research study computationally examined the thermal decomposition of three molecules, 3,6-dihydro-2H-pyran, 4-methyl-3,6-dihydro-2H-pyran, and 2,6-dimethyl-3,6-dihydro-2H-pyran, using the PBE0/6-311+G(d,p) level of theory and a concerted mechanism with a 6-member cyclic transition state. For this analysis, kinetic and thermodynamic parameters were calculated for reactions within a temperature range of 584 to 633 K and compared with experimental data. Our results revealed that methyl substituents at 2, 4, and 6 positions decrease the activation free energy of the molecules. Even though the evaluated reactions exhibited high absolute synchronicity, significant differences were observed regarding the extent of their bond evolution. Full article
(This article belongs to the Section Theoretical and Computational Chemistry)
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11 pages, 1567 KiB  
Article
Coordination Modes of Ortho-Substituted Benzoates Towards Divalent Copper Centres in the Presence of Diimines
by Ioannis Loukas, Eirini Frantzana, Antonios Hatzidimitriou, Demetrios Tzimopoulos and Pericles Akrivos
Chemistry 2024, 6(6), 1374-1384; https://doi.org/10.3390/chemistry6060081 - 4 Nov 2024
Viewed by 1078
Abstract
The coordination modes of several ortho-substituted benzoates towards the copper(II) centre are investigated. The coordination environment of the metal ion includes nitrogen atoms from 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen) and occasionally oxygen atoms from coordinated water, ethanol molecules, or nitrate ions. The [...] Read more.
The coordination modes of several ortho-substituted benzoates towards the copper(II) centre are investigated. The coordination environment of the metal ion includes nitrogen atoms from 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen) and occasionally oxygen atoms from coordinated water, ethanol molecules, or nitrate ions. The compounds are investigated by a variety of spectroscopic methods and by single-crystal X-ray diffraction. Although the reaction scheme involved equimolar amounts of the reactants, cationic dinuclear compounds with a metal/benzoate/diimine ratio of 2:3:2 have been realized, cationic in nature regardless of the counter anion used. Furthermore, the carboxylate moieties display a range of twisting relative to the orientation of the benzene ring to which they are attached. Full article
(This article belongs to the Section Inorganic and Solid State Chemistry)
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11 pages, 2947 KiB  
Article
Preparation of Hierarchical Porous ZIF-67 and Its Application in Zinc Battery Separator
by Tian Zhao, Jiangrong Yu, Pengcheng Xiao, Saiqun Nie, Shilin Peng, Jiayao Chen, Fuli Luo, Christoph Janiak and Yi Chen
Chemistry 2024, 6(6), 1363-1373; https://doi.org/10.3390/chemistry6060080 - 31 Oct 2024
Cited by 4 | Viewed by 1473
Abstract
This study successfully prepared a hierarchically porous ZIF-67 (H-ZIF-67) by incorporating the polyvinylpyrrolidone (PVP) at room temperature. Compared to standard control ZIF-67 (C-ZIF-67) with a yield of 81% and a BET specific surface area of 1228 m2·g−1, the H-ZIF-67 [...] Read more.
This study successfully prepared a hierarchically porous ZIF-67 (H-ZIF-67) by incorporating the polyvinylpyrrolidone (PVP) at room temperature. Compared to standard control ZIF-67 (C-ZIF-67) with a yield of 81% and a BET specific surface area of 1228 m2·g−1, the H-ZIF-67 not only exhibited improved crystallinity and pore structure but also achieved a yield of up to 93% and a BET specific surface area of 1457 m2·g−1. Due to its hierarchically porous structure, H-ZIF-67 demonstrated excellent adsorption capacity and efficiency for methylene orange (MO). Additionally, the composite separator created by combining H-ZIF-67 with nanocellulose (CNF) exhibited remarkable uniformity and dispersion in zinc batteries. In comparison to a conventional CNF separator, the porous structure and high specific surface area of H-ZIF-67 significantly enhanced its electrolyte wettability and Zn2+ transport rates. Its abundant Lewis acid sites effectively promoted the uniform deposition of Zn2+, thereby suppressing the formation of zinc dendrites and improving the cycling and safety performance of zinc-ion batteries. Experimental results indicate that the ion conductivity of the membrane was 4.31 mS·cm−1, the electrolyte absorption rate was 316%, and it could cycle stable for over 4000 h at a current density of 1 mA·cm−2 with a discharge capacity of 1 mAh·cm−2. This achievement will open up new avenues for the preparation and application of ZIF-67 composite separators in aqueous zinc-ion batteries. Full article
(This article belongs to the Special Issue Nano/Micro MOF-Based Materials for Energy Conversion and Storage)
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16 pages, 1575 KiB  
Article
Synthesis and Bioactivity Assessment of N-Aryl-Azasesamins
by Jiri Wu, Xubing Qi, Yogini S. Jaiswal, Cui Lin, Xun Song, Xinrong Xie, Shaoyang Su, Yifu Guan, Leonard L. Williams and Hedong Bian
Chemistry 2024, 6(6), 1347-1362; https://doi.org/10.3390/chemistry6060079 - 30 Oct 2024
Viewed by 1005
Abstract
Sesamin, a tetrahydrofuran lignan, has gained significant attention over the past few decades due to its versatile medicinal activities. However, until now, the research on sesamin analogues has not been explored extensively. In this study, a series of new N-aryl-azasesamins were synthesized [...] Read more.
Sesamin, a tetrahydrofuran lignan, has gained significant attention over the past few decades due to its versatile medicinal activities. However, until now, the research on sesamin analogues has not been explored extensively. In this study, a series of new N-aryl-azasesamins were synthesized for the first time using sesamin as a raw material. The mechanism of the key breakage of the ethereal bond of the tetrahydrofuran ring in sesamin has been studied. The configuration of C6 in N-aryl-azasesamins was confirmed through NMR and X-ray single crystal refraction analyses. The results showed that the configuration of N-aryl-azasesamins was opposite to sesamin in C6. Subsequently, the N-aryl-azasesamins were evaluated for their antifungal and antitumor activities via micro-broth dilution and MTT assays. It was observed that none of the N-aryl-azasesamins exhibited inhibitory activity against the growth of C. albicans and C. neoformans at a concentration of 100 μg/mL. Most analogues showed no activity against HepG2 cells. However, 21c and 21k demonstrated antitumor activity after 24 h of incubation with IC50 values of 6.49 μM and 4.73 μM, respectively. These results suggest that some N-aryl-azasesamins exhibit significantly enhanced antitumor activity compared with sesamin. Full article
(This article belongs to the Section Biological and Natural Products)
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11 pages, 742 KiB  
Article
LC-ESI-MS and GC-MS Profiling, Chemical Composition, and Cytotoxic Activity of Endophytic Fungus Pleosporales sp. Derived from Artemisia annua
by Mamdouh Nabil Samy, Eman Zekry Attia, Basma Ali Khalifa, Usama Ramadan Abdelmohsen and Samir Anis Ross
Chemistry 2024, 6(6), 1336-1346; https://doi.org/10.3390/chemistry6060078 - 26 Oct 2024
Viewed by 1585
Abstract
The chemical profiling of ethyl acetate extract of the endophytic fungus Pleosporales sp. using liquid chromatography–electrospray ionization–mass spectrometry (LC-ESI-MS) revealed the presence of 12 metabolites of different chemical classes such as steroids, α-pyrones, asterric acid derivatives, and quinones. Additionally, the gas chromatography–mass spectrometry [...] Read more.
The chemical profiling of ethyl acetate extract of the endophytic fungus Pleosporales sp. using liquid chromatography–electrospray ionization–mass spectrometry (LC-ESI-MS) revealed the presence of 12 metabolites of different chemical classes such as steroids, α-pyrones, asterric acid derivatives, and quinones. Additionally, the gas chromatography–mass spectrometry (GC-MS) profiling of the ethyl acetate (EtOAc) and methanol extracts exhibited the presence of fatty acids and their esters, in which methyl palmitate (18.72%, and 25.48%, respectively) and methyl linoleate (11.92% and 23.39%, respectively) were found in both extracts. On the other hand, palmitic acid (12.60%), methyl oleate (26.90%), oleic acid (4.01%) and linoleic acid (3.25%) were present only in methanol extract. Furthermore, ethyl palmitate (12.60%), 13-octadecenoic acid (19.36%), and ethyl linoleate (3.25%) occurred in EtOAc extract. A phytochemical investigation of both extracts led to the isolation of fatty acids such as palmitic acid (18), oleic acid (20), and linoleic acid (21) and their esters including methyl palmitate (13), methyl stearate (22), methyl linoleate (16), methyl 3-hydroxy-5-methylhexanoate (23), and monomethyl azelate (27), in addition to monoacyl derivatives of glycerol such as 3,3-dihydroxypropyl hexadecanoate (24), 2,3-dihydroxypropyl elaidate (25), and 1-linoleoyl-sn-glycerol (26). The structures of the isolated compounds were identified by different spectroscopic analyses including 1H- and 13C-NMR and GC-MS. The EtOAc extract exhibited a cytotoxic effect against MCF-7 and HepG-2 cell lines, with IC50 values of 4.12 ± 0.10 and 10.05 ± 0.05 μg/mL, respectively. Full article
(This article belongs to the Section Biological and Natural Products)
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10 pages, 2811 KiB  
Article
Understanding the Enhanced Separation Mechanism of C2H4/C2H6 at Low Pressure by HKUST−1
by Wenpeng Xie, Qiuju Fu, Xiangjun Kong, Xiangsen Yuan, Lingzhi Yang, Liting Yan and Xuebo Zhao
Chemistry 2024, 6(6), 1326-1335; https://doi.org/10.3390/chemistry6060077 - 25 Oct 2024
Viewed by 1614
Abstract
The production of ethylene (C2H4) is typically accompanied by the formation of impurities like ethane (C2H6), making the separation of C2H4 and C2H6 crucial in industrial processes. Here, we [...] Read more.
The production of ethylene (C2H4) is typically accompanied by the formation of impurities like ethane (C2H6), making the separation of C2H4 and C2H6 crucial in industrial processes. Here, we investigated the S-shaped adsorption phenomenon of C2H6 on the metal–organic framework HKUST−1. The virial equation is used to fit the C2H6 and C2H4 adsorption isotherms under low coverage. The results showed that the repulsion energy between neighboring C2H6 molecules was significantly higher than that between neighboring C2H4 molecules, which was an important reason for the lower adsorption of C2H6 by HKUST−1 at low coverage. As more molecules are adsorbed, gas molecules aggregate within pores, leading to more hydrogen bonds formed between HKUST−1 and larger-sized C2H6 under high coverage conditions. This phenomenon plays a crucial role in the S-shaped adsorption behavior of HKUST−1 on C2H6. Additionally, this unique adsorption behavior allows for the efficient separation of C2H4/C2H6 mixtures at low pressures. The ideal adsorbed solution theory (IAST) selectivity of HKUST−1 for C2H4/C2H6 mixtures was 3.78 at 283 K and 1 bar, but increased significantly to 7.53 under low pressure. This unique mechanism provides a theoretical basis for the low-pressure separation of C2H4/C2H6 by HKUST−1 and establishes a solid foundation for future practical research applications. Full article
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