Molecules

20 pages, 5306 KiB

Open AccessArticle

Anticancer Activity and Molecular Mechanisms of Acetylated and Methylated Quercetin in Human Breast Cancer Cells

by Kozue Sakao, Shihomi Hamamoto, Daigo Urakawa, Ziyu He and De-Xing Hou

Molecules 2024, 29(10), 2408; https://doi.org/10.3390/molecules29102408 - 20 May 2024

Cited by 1 | Viewed by 1467

Quercetin, a flavonoid polyphenol found in many plants, has garnered significant attention due to its potential cancer chemoprevention. Our previous studies have shown that acetyl modification of the hydroxyl group of quercetin altered its antitumor effects in HepG2 cells. However, the antitumor effect [...] Read more.

Quercetin, a flavonoid polyphenol found in many plants, has garnered significant attention due to its potential cancer chemoprevention. Our previous studies have shown that acetyl modification of the hydroxyl group of quercetin altered its antitumor effects in HepG2 cells. However, the antitumor effect in other cancer cells with different gene mutants remains unknown. In this study, we investigated the antitumor effect of quercetin and its methylated derivative 3,3′,4′,7-O-tetramethylquercetin (4Me-Q) and acetylated derivative 3,3′,4′,7-O-tetraacetylquercetin (4Ac-Q) on two human breast cancer cells, MCF-7 (wt-p53, caspase-3-ve) and MDA-MB-231 (mt-p53, caspase-3+ve). The results demonstrated that 4Ac-Q exhibited significant cell proliferation inhibition and apoptosis induction in both MCF-7 and MDA-MB-231 cells. Conversely, methylation of quercetin was found to lose the activity. The human apoptosis antibody array revealed that 4Ac-Q might induce apoptosis in MCF-7 cells via a p53-dependent pathway, while in MDA-MB-231 cells, it was induced via a caspase-3-dependent pathway. Furthermore, an evaluation using a superoxide inhibitor, MnTBAP, revealed 4Ac-Q-induced apoptosis in MCF-7 cells in a superoxide-independent manner. These findings provide valuable insights into the potential of acetylated quercetin as a new approach in cancer chemoprevention and offer new avenues for health product development. Full article

(This article belongs to the Special Issue Probing Pharmacological and Biological Performance of Synthetic and Natural Compounds—2nd Edition)

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20 pages, 11953 KiB

Open AccessArticle

Protic Processes in an Extended Pyrazinacene: The Case of Dihydrotetradecaazaheptacene

by Aël Cador, Samia Kahlal, Gary J. Richards, Jean-François Halet and Jonathan P. Hill

Molecules 2024, 29(10), 2407; https://doi.org/10.3390/molecules29102407 - 20 May 2024

Viewed by 973

Abstract

Pyrazinacenes are linearly fused heteroaromatic rings, with N atoms replacing all apical CH moieties. Component rings may exist in a reduced state, having NH groups instead of N, causing cross-conjugation. These compounds have interesting optical and electronic properties, including strong fluorescence in the [...] Read more.

Pyrazinacenes are linearly fused heteroaromatic rings, with N atoms replacing all apical CH moieties. Component rings may exist in a reduced state, having NH groups instead of N, causing cross-conjugation. These compounds have interesting optical and electronic properties, including strong fluorescence in the near-infrared region and photocatalytic properties, leading to diverse possible applications in bio-imaging and organic synthesis, as well as obvious molecular electronic uses. In this study, we investigated the behavior of seven-ring pyrazinacene 2,3,11,12-tetraphenyl-7,16-dihydro-1,4,5,6,7,8,9,12,13,14,15,16,17,18-tetradecaazaheptacene (Ph₄H₂N₁₄HEPT), with an emphasis on protic processes, including oxidation, tautomerism, deprotonation, and protonation, and the species resulting from those processes. We used computational methods to optimize the structures of the different species and generate/compare molecular orbital structures. The aromaticity of the species generated by the different processes was assessed using the nucleus-independent chemical shifts, and trends in the values were associated with the different transformations of the pyrazinacene core. The computational data were compared with experimental data obtained from synthetic samples of the molecule tBu₈Ph₄H₂N₁₄HEPT. Full article

(This article belongs to the Special Issue Fused-Nitrogen-Containing Heterocycles (Second Edition))

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14 pages, 5553 KiB

Open AccessArticle

Computational Predictive and Electrochemical Detection of Metabolites (CP-EDM) of Piperine

by Ridho Asra, Ana P. R. Povinelli, Gabriel Zazeri and Alan M. Jones

Molecules 2024, 29(10), 2406; https://doi.org/10.3390/molecules29102406 - 20 May 2024

Cited by 1 | Viewed by 1377

Abstract

In this article, we introduce a proof-of-concept strategy, Computational Predictive and Electrochemical Detection of Metabolites (CP-EDM), to expedite the discovery of drug metabolites. The use of a bioactive natural product, piperine, that has a well-curated metabolite profile but an unpredictable computational metabolism (Biotransformer [...] Read more.

In this article, we introduce a proof-of-concept strategy, Computational Predictive and Electrochemical Detection of Metabolites (CP-EDM), to expedite the discovery of drug metabolites. The use of a bioactive natural product, piperine, that has a well-curated metabolite profile but an unpredictable computational metabolism (Biotransformer v3.0) was selected. We developed an electrochemical reaction to oxidize piperine into a range of metabolites, which were detected by LC-MS. A series of chemically plausible metabolites were predicted based on ion fragmentation patterns. These metabolites were docked into the active site of CYP3A4 using Autodock4.2. From the clustered low-energy profile of piperine in the active site, it can be inferred that the most likely metabolic position of piperine (based on intermolecular distances to the Fe-oxo active site) is the benzo[d][1,3]dioxole motif. The metabolic profile was confirmed by comparison with the literature, and the electrochemical reaction delivered plausible metabolites, vide infra, thus, demonstrating the power of the hyphenated technique of tandem electrochemical detection and computational evaluation of binding poses. Taken together, we outline a novel approach where diverse data sources are combined to predict and confirm a metabolic outcome for a bioactive structure. Full article

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18 pages, 6855 KiB

Open AccessArticle

Efficient Removal of Nickel from Wastewater Using Copper Sulfate–Ammonia Complex Modified Activated Carbon: Adsorption Performance and Mechanism

by Yifei Wang, Xiaoxiao Yan, Yidi Zhang, Xiaoxin Qin, Xubiao Yu, Li Jiang and Bing Li

Molecules 2024, 29(10), 2405; https://doi.org/10.3390/molecules29102405 - 20 May 2024

Viewed by 1302

Abstract

The necessity to eliminate nickel (Ni) from wastewater stems from its environmental and health hazards. To enhance the Ni adsorption capacity, this research applied a copper sulfate–ammonia complex (tetraamminecopper (II) sulfate monohydrate, [Cu(NH₃)₄]SO₄·H₂O) as a [...] Read more.

The necessity to eliminate nickel (Ni) from wastewater stems from its environmental and health hazards. To enhance the Ni adsorption capacity, this research applied a copper sulfate–ammonia complex (tetraamminecopper (II) sulfate monohydrate, [Cu(NH₃)₄]SO₄·H₂O) as a modifying agent for a Phragmites australis-based activated carbon preparation. The physiochemical properties of powdered activated carbon (PAC) and a modified form ([Cu(NH₃)₄]-PAC) were examined by measuring their surface areas, analyzing their elemental composition, and using Boehm’s titration method. Batch experiments were conducted to investigate the impact of various factors, such as Ni(II) concentration, contact time, pH, and ionic strength, on its substance adsorption capabilities. Additionally, the adsorption mechanisms of Ni(II) onto activated carbon were elucidated via Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The findings indicated that modified activated carbon ([Cu(NH₃)₄]-PAC) exhibited a lower surface area and total volume than the original activated carbon (PAC). The modification of PAC enhanced its surface’s relative oxygen and nitrogen content, indicating the incorporation of functional groups containing these elements. Furthermore, the modified activated carbon, [Cu(NH₃)₄]-PAC, exhibited superior adsorption capacity relative to unmodified PAC. Both adsorbents’ adsorption behaviors conformed to the Langmuir model and the pseudo-second-order kinetics model. The Ni(II) removal efficiency of PAC and [Cu(NH₃)₄]-PAC diminished progressively with rising ionic strength. Modified activated carbon [Cu(NH₃)₄]-PAC demonstrated notable pH buffering and adaptability. The adsorption mechanism for Ni(II) on activated carbon involves surface complexation, cation exchange, and electrostatic interaction. This research presents a cost-efficient preparation technique for preparing activated carbon with enhanced Ni(II) removal capabilities from wastewater and elucidates its underlying adsorption mechanisms. Full article

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16 pages, 4927 KiB

Open AccessArticle

Optimization of Biodiesel Production Process Using MoO₃ Catalysts and Residual Oil: A Comprehensive Experimental 2³ Study

by Adriano Lima da Silva, Helder de Lucena Pereira, Herbet Bezerra Sales, Juliana Kelly Dionízio, Mary Cristina Ferreira Alves, Danyelle Garcia Guedes, Carlos Bruno Barreto Luna and Ana Cristina Figueiredo de Melo Costa

Molecules 2024, 29(10), 2404; https://doi.org/10.3390/molecules29102404 - 20 May 2024

Cited by 2 | Viewed by 1124

Abstract

The study aimed to utilize MoO₃ catalysts, produced on a pilot scale via combustion reaction, to produce biodiesel from residual oil. Optimization of the process was conducted using a 2³ experimental design. Structural characterization of the catalysts was performed through X-ray [...] Read more.

The study aimed to utilize MoO₃ catalysts, produced on a pilot scale via combustion reaction, to produce biodiesel from residual oil. Optimization of the process was conducted using a 2³ experimental design. Structural characterization of the catalysts was performed through X-ray diffraction, fluorescence, Raman spectroscopy, and particle size distribution analyses. At the same time, thermal properties were examined via thermogravimetry and differential thermal analysis. Catalytic performance was assessed following process optimization. α-MoO₃ exhibited a monophasic structure with orthorhombic phase, whereas α/h-MoO₃ showed a biphasic structure. α-MoO₃ had a larger crystallite size and higher crystallinity, with thermal stability observed up to certain temperatures. X-ray fluorescence confirmed molybdenum oxide predominance in the catalysts, with traces of iron oxide. Particle size distribution analyses revealed polymodal distributions attributed to structural differences. Both catalysts demonstrated activity under all conditions tested, with ester conversions ranging from 93% to 99%. The single-phase catalyst had a long life cycle and was reusable for six biodiesel production cycles. The experimental design proved to be predictive and significant, with the type of catalyst being the most influential variable. Optimal conditions included α-MoO₃ catalyst, oil/alcohol ratio of 1/15, and a reaction time of 60 min, resulting in high biodiesel conversion rates and showcasing the viability of MoO₃ catalysts in residual oil biodiesel production. Full article

(This article belongs to the Special Issue Catalysts: New Materials for Green Chemistry)

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18 pages, 4966 KiB

Open AccessArticle

Conyza canadensis from Jordan: Phytochemical Profiling, Antioxidant, and Antimicrobial Activity Evaluation

by Lina M. Barhoumi, Ashok K. Shakya, O’la Al-Fawares and Hala I. Al-Jaber

Molecules 2024, 29(10), 2403; https://doi.org/10.3390/molecules29102403 - 20 May 2024

Cited by 1 | Viewed by 1479

Abstract

In this investigation, the chemical composition of the hydro-distilled essential oil (HD-EO), obtained from the fresh aerial parts (inflorescence heads (Inf), leaves (L), and stems (St)) of Conyza canadensis growing wild in Jordan was determined by GC/MS. Additionally, the methanolic extract obtained from [...] Read more.

In this investigation, the chemical composition of the hydro-distilled essential oil (HD-EO), obtained from the fresh aerial parts (inflorescence heads (Inf), leaves (L), and stems (St)) of Conyza canadensis growing wild in Jordan was determined by GC/MS. Additionally, the methanolic extract obtained from the whole aerial parts of C. canadensis (CCM) was examined for its total phenolic content (TPC), total flavonoids content (TFC), DPPH radical scavenging activity, iron chelating activity and was then analyzed with LC-MS/MS for the presence of certain selected phenolic compounds and flavonoids. The GC/MS analysis of CCHD-EOs obtained from the different aerial parts revealed the presence of (2E, 8Z)-matricaria ester as the main component, amounting to 15.4% (Inf), 60.7% (L), and 31.6% (St) of the total content. Oxygenated monoterpenes were the main class of volatile compounds detected in the Inf-CCHD-EO. However, oils obtained from the leaves and stems were rich in polyacetylene derivatives. The evaluation of the CCM extract showed a richness in phenolic content (95.59 ± 0.40 mg GAE/g extract), flavonoids contents (467.0 ± 10.5 mg QE/ g extract), moderate DPPH radical scavenging power (IC₅₀ of 23.75 ± 0.86 µg/mL) and low iron chelating activity (IC₅₀ = 5396.07 ± 15.05 µg/mL). The LC-MS/MS profiling of the CCM extract allowed for the detection of twenty-five phenolic compounds and flavonoids. Results revealed that the CCM extract contained high concentration levels of rosmarinic acid (1441.1 mg/kg plant), in addition to caffeic acid phenethyl ester (231.8 mg/kg plant). An antimicrobial activity assessment of the CCM extract against a set of Gram-positive and Gram-negative bacteria, in addition to two other fungal species including Candida and Cryptococcus, showed significant antibacterial activity of the extract against S. aureus with MIC value of 3.125 µg/mL. The current study is the first phytochemical screening for the essential oil and methanolic extract composition of C. canadensis growing in Jordan, its antioxidant and antimicrobial activity. Full article

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18 pages, 1325 KiB

Open AccessPerspective

Molecular and Therapeutic Roles of Non-Coding RNAs in Oral Cancer—A Review

by Vidhya Rekha Umapathy, Prabhu Manickam Natarajan and Bhuminathan Swamikannu

Molecules 2024, 29(10), 2402; https://doi.org/10.3390/molecules29102402 - 20 May 2024

Cited by 4 | Viewed by 1282

Abstract

Oral cancer (OC) is among the most common malignancies in the world. Despite advances in therapy, the worst-case scenario for OC remains metastasis, with a 50% survival rate. Therefore, it is critical to comprehend the pathophysiology of the condition and to create diagnostic [...] Read more.

Oral cancer (OC) is among the most common malignancies in the world. Despite advances in therapy, the worst-case scenario for OC remains metastasis, with a 50% survival rate. Therefore, it is critical to comprehend the pathophysiology of the condition and to create diagnostic and treatment plans for OC. The development of high-throughput genome sequencing has revealed that over 90% of the human genome encodes non-coding transcripts, or transcripts that do not code for any proteins. This paper describes the function of these different kinds of non-coding RNAs (ncRNAs) in OC as well as their intriguing therapeutic potential. The onset and development of OC, as well as treatment resistance, are linked to dysregulated ncRNA expression. These ncRNAs’ potentially significant roles in diagnosis and prognosis have been suggested by their differing expression in blood or saliva. We have outlined every promising feature of ncRNAs in the treatment of OC in this study. Full article

(This article belongs to the Section Medicinal Chemistry)

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26 pages, 4445 KiB

Open AccessReview

A Review of Sisal Fiber-Reinforced Geopolymers: Preparation, Microstructure, and Mechanical Properties

by Wenbo Qu, Bowen Niu, Chun Lv and Jie Liu

Molecules 2024, 29(10), 2401; https://doi.org/10.3390/molecules29102401 - 20 May 2024

Cited by 4 | Viewed by 1536

Abstract

The early strength of geopolymers (GPs) and their composites is higher, and the hardening speed is faster than that of ordinary cementitious materials. Due to their wide source of raw materials, low energy consumption in the production process, and lower emissions of pollutants, [...] Read more.

The early strength of geopolymers (GPs) and their composites is higher, and the hardening speed is faster than that of ordinary cementitious materials. Due to their wide source of raw materials, low energy consumption in the production process, and lower emissions of pollutants, they are considered to have the most potential to replace ordinary Portland cement. However, similar to other inorganic materials, the GPs themselves have weak flexural and tensile strength and are sensitive to micro-cracks. Improving the toughness of GP materials can be achieved by adding an appropriate amount of fiber materials into the matrix. The use of discrete staple fibers shows great potential in improving the toughness of GPs. Sisal is a natural fiber that is reproducible and easy to obtain. Due to its good mechanical properties, low cost, and low carbon energy usage, sisal fiber (SF) is a GP composite reinforcement with potential development. In this paper, the research progress on the effect of SF on the properties of GP composites in recent decades is reviewed. It mainly includes the chemical composition and physical properties of SFs, the preparation technology of sisal-reinforced geopolymers (SFRGs), the microstructure analysis of the interface of SFs and the GP matrix, and the macroscopic mechanical properties of SFRGs. The properties of SFs make them have good bonding properties with the GP matrix. The addition of SFs can improve the flexural strength and tensile strength of GP composites, and SFRGs have good engineering application prospects. Full article

(This article belongs to the Section Macromolecular Chemistry)

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17 pages, 6384 KiB

Open AccessArticle

Antiproliferative and Pro-Apoptotic Activity and Tubulin Dynamics Modulation of 1H-Benzimidazol-2-yl Hydrazones in Human Breast Cancer Cell Line MDA-MB-231

by Denitsa Yancheva, Maria Argirova, Irina Georgieva, Vanya Milanova, Maya Guncheva, Miroslav Rangelov, Nadezhda Todorova and Rumiana Tzoneva

Molecules 2024, 29(10), 2400; https://doi.org/10.3390/molecules29102400 - 20 May 2024

Viewed by 1079

Abstract

(1) Background: The aim of the work is the evaluation of in vitro antiproliferative and pro-apoptotic activity of four benzimidazole derivatives containing colchicine-like and catechol-like moieties with methyl group substitution in the benzimidazole ring against highly invasive breast cancer cell line MDA-MB-231 and [...] Read more.

(1) Background: The aim of the work is the evaluation of in vitro antiproliferative and pro-apoptotic activity of four benzimidazole derivatives containing colchicine-like and catechol-like moieties with methyl group substitution in the benzimidazole ring against highly invasive breast cancer cell line MDA-MB-231 and their related impairment of tubulin dynamics. (2) Methods: The antiproliferative activity was assessed with the MTT assay. Alterations in tubulin polymerization were evaluated with an in vitro tubulin polymerization assay and a docking analysis. (3) Results: All derivatives showed time-dependent cytotoxicity with IC₅₀ varying from 40 to 60 μM after 48 h and between 13 and 20 μM after 72 h. Immunofluorescent and DAPI staining revealed the pro-apoptotic potential of benzimidazole derivatives and their effect on tubulin dynamics in living cells. Compound 5d prevented tubulin aggregation and blocked mitosis, highlighting the importance of the methyl group and the colchicine-like fragment. (4) Conclusions: The benzimidazole derivatives demonstrated moderate cytotoxicity towards MDA-MB-231 by retarding the initial phase of tubulin polymerization. The derivative 5d containing a colchicine-like moiety and methyl group substitution in the benzimidazole ring showed potential as an antiproliferative agent and microtubule destabilizer by facilitating faster microtubule aggregation and disrupting cellular and nuclear integrity. Full article

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14 pages, 3184 KiB

Open AccessArticle

Study on Quality Characteristic of Chebulae Fructus and Its Adulterants and Degradation Pathway of Hydrolyzable Tannins

by Jian Xu, Xiangdong Wang, Huijuan Yu, Xin Chai, Min Zhang, Hong-Hua Wu and Yuefei Wang

Molecules 2024, 29(10), 2399; https://doi.org/10.3390/molecules29102399 - 20 May 2024

Cited by 1 | Viewed by 1085

Abstract

Chebulae Fructus (CF) is known as one of the richest sources of hydrolyzable tannins (HTs). In this study, ultra-performance liquid chromatography coupled with a photodiode array detector method was established for simultaneous determination of the 12 common phenolcarboxylic and tannic constituents (PTCs). Using [...] Read more.

Chebulae Fructus (CF) is known as one of the richest sources of hydrolyzable tannins (HTs). In this study, ultra-performance liquid chromatography coupled with a photodiode array detector method was established for simultaneous determination of the 12 common phenolcarboxylic and tannic constituents (PTCs). Using this method, quantitative analysis was accomplished in CF and other four adulterants, including Terminaliae Belliricae Fructus, Phyllanthi Fructus, Chebulae Fructus Immaturus, and Canarii Fructus. Based on a quantitative analysis of the focused compounds, discrimination of CF and other four adulterants was successfully accomplished by hierarchical cluster analysis and principal component analysis. Additionally, the total contents of the 12 compounds that we focused on in this study were unveiled as 148.86 mg/g, 96.14 mg/g, and 18.64 mg/g in exocarp, mesocarp, and endocarp and seed of CF, respectively, and PTCs were witnessed to be the most abundant in the exocarp of CF. Noticeably, the HTs (chebulagic acid, chebulanin acid, chebulinic acid, and punicalagin) were observed to be ultimately degraded to chebulic acid, gallic acid, and ellagic acid during sunlight-drying of the fresh fruits. As a result, our study indicated that CF and its adulterants could be distinguished by the observed 12 PTCs, which were mainly distributed in the exocarp of the fruits. The HTs were prone to degrade into the three simple phenolcarboxylic acids during drying or processing, allowing us to obtain a more comprehensive understanding of the PTCs, with great significance in the improved quality of CF and related products. Full article

(This article belongs to the Section Analytical Chemistry)

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14 pages, 5148 KiB

Open AccessArticle

An N-Rich Polymer for the Selective Recovery of Gold from Wastewater

by Haonan Dong, Ge Shang, Yi Zhang, Enrui Dai, Mingdong Shao, Chunfeng Chen, Hongxing He, Zhifeng Nie, Mingyang Xiong, Deren Miao and Sibiao Zhao

Molecules 2024, 29(10), 2398; https://doi.org/10.3390/molecules29102398 - 20 May 2024

Viewed by 960

Abstract

The recovery of valuable gold from wastewater is of great interest because of the widespread use of the precious metal in various fields and the pollution generated by gold-containing wastes in water. In this paper, a water-insoluble cross-linked adsorbent material (TE) based on [...] Read more.

The recovery of valuable gold from wastewater is of great interest because of the widespread use of the precious metal in various fields and the pollution generated by gold-containing wastes in water. In this paper, a water-insoluble cross-linked adsorbent material (TE) based on cyanuric chloride (TCT) and ethylenediamine (EDA) was designed and used for the adsorption of Au(III) from wastewater. It was found that TE showed extremely high selectivity (D = 49,213.46) and adsorption capacity (256.19 mg/g) for Au(III) under acidic conditions. The adsorption rate remained above 90% eVen after five adsorption–desorption cycles. The adsorption process followed the pseudo-first-order kinetic model and the Freundlich isotherm model, suggesting that physical adsorption with a multilayer molecular overlay dominates. Meanwhile, the adsorption mechanism was obtained by DFT calculation and XPS analysis, and the adsorption mechanism was mainly the electrostatic interaction and electron transfer between the protonated N atoms in the adsorbent (TE) and AuCl₄⁻, which resulted in the redox reaction. The whole adsorption process was the result of the simultaneous action of physical and chemical adsorption. In conclusion, the adsorbent material TE shows great potential for gold adsorption and recovery. Full article

(This article belongs to the Special Issue Recent Advances in Porous Materials)

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20 pages, 12379 KiB

Open AccessReview

Opportunities, Challenges, and Scientific Progress in Hemp Crops

by Kacper Piotr Kaminski, Julia Hoeng, Fernando Goffman, Walter K. Schlage and Diogo Latino

Molecules 2024, 29(10), 2397; https://doi.org/10.3390/molecules29102397 - 20 May 2024

Cited by 4 | Viewed by 3980

Abstract

The resurgence of cannabis (Cannabis sativa L.) has been propelled by changes in the legal framework governing its cultivation and use, increased demand for hemp-derived products, and studies recognizing the industrial and health benefits of hemp. This has led to the creation [...] Read more.

The resurgence of cannabis (Cannabis sativa L.) has been propelled by changes in the legal framework governing its cultivation and use, increased demand for hemp-derived products, and studies recognizing the industrial and health benefits of hemp. This has led to the creation of novel high-cannabidiol, low-Δ⁹-tetrahydrocannabinol varieties, enabling hemp crop expansion worldwide. This review elucidates the recent implications for hemp cultivation in Europe, with a focus on the legislative impacts on the cultivation practices, prospective breeding efforts, and dynamic scientific landscape surrounding this crop. We also review the current cultivars’ cannabinoid composition of the European hemp market and its major differences with that of the United States. Full article

(This article belongs to the Special Issue Recent Advances in Cannabis and Hemp Research)

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16 pages, 10592 KiB

Open AccessArticle

Novel 9-Methylanthracene Derivatives as p53 Activators for the Treatment of Glioblastoma Multiforme

by Yuxin Feng, Yingjie Wang, Xiaoxue Li, Ziqiang Sun, Sihan Qiang, Hongbo Wang and Yi Liu

Molecules 2024, 29(10), 2396; https://doi.org/10.3390/molecules29102396 - 19 May 2024

Viewed by 1304

Abstract

Glioblastoma multiforme, a highly aggressive and lethal brain tumor, is a substantial clinical challenge and a focus of increasing concern globally. Hematological toxicity and drug resistance of first-line drugs underscore the necessity for new anti-glioma drug development. Here, 43 anthracenyl skeleton compounds as [...] Read more.

Glioblastoma multiforme, a highly aggressive and lethal brain tumor, is a substantial clinical challenge and a focus of increasing concern globally. Hematological toxicity and drug resistance of first-line drugs underscore the necessity for new anti-glioma drug development. Here, 43 anthracenyl skeleton compounds as p53 activator XI-011 analogs were designed, synthesized, and evaluated for their cytotoxic effects. Five compounds (13d, 13e, 14a, 14b, and 14n) exhibited good anti-glioma activity against U87 cells, with IC₅₀ values lower than 2 μM. Notably, 13e showed the best anti-glioma activity, with an IC₅₀ value up to 0.53 μM, providing a promising lead compound for new anti-glioma drug development. Mechanistic analyses showed that 13e suppressed the MDM4 protein expression, upregulated the p53 protein level, and induced cell cycle arrest at G2/M phase and apoptosis based on Western blot and flow cytometry assays. Full article

(This article belongs to the Special Issue Anticancer Drug Discovery and Development II)

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11 pages, 3616 KiB

Open AccessCommunication

Extraction of Dibenzyl Disulfide from Transformer Oils by Acidic Ionic Liquid

by Lili Zhang, Pei Peng, Qian Pan, Fang Wan and Huaxin Zhang

Molecules 2024, 29(10), 2395; https://doi.org/10.3390/molecules29102395 - 19 May 2024

Viewed by 1181

Abstract

In recent years, dibenzyl disulfide (DBDS) in transformer oils has caused many transformer failures around the world, and its removal has attracted more attention. In this work, nine imidazolium-based ionic liquids (ILs) were applied as effective, green desulfurization extractants for DBDS-containing transformer oil [...] Read more.

In recent years, dibenzyl disulfide (DBDS) in transformer oils has caused many transformer failures around the world, and its removal has attracted more attention. In this work, nine imidazolium-based ionic liquids (ILs) were applied as effective, green desulfurization extractants for DBDS-containing transformer oil for the first time. The results show that the desulfurization ability of the ILs for DBDS followed the order of [BMIM]FeCl₄ > [BMIM]N(CN)₂ > [BMIM]SCN > [BMIM](C₄H₉O)₂PO₂ > [BMIM]MeSO₄ > [BMIM]NTf₂ > [BMIM]OTf > [BMIM]PF₆ > [BMIM]BF₄. Especially, [BMIM]FeCl₄ ionic liquid had excellent removal efficiency for DBDS, with its S partition coefficient K_N (S) being up to 2642, which was much higher than the other eight imidazolium-based ILs. Moreover, the extractive performance of [BMIM]FeCl₄ increased with an increasing molar ratio of FeCl₃ to [BMIM]Cl, which was attributed to its Lewis acidity and fluidity. [BMIM]FeCl₄ ionic liquid could also avail in the desulfurization of diphenyl sulfide (DPS) from model oils. The experimental results demonstrate that π−π action, π-complexation, and Lewis acid−base interaction played important roles in the desulfurization process. Finally, the ([BMIM]FeCl₄) ionic liquid could be recycled five times without a significant decrease in extractive ability. Full article

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36 pages, 5324 KiB

Open AccessReview

Bioactive Compounds from Medicinal Plants as Potential Adjuvants in the Treatment of Mild Acne Vulgaris

by Mariateresa Cristani and Nicola Micale

Molecules 2024, 29(10), 2394; https://doi.org/10.3390/molecules29102394 - 19 May 2024

Viewed by 3050

Abstract

In recent years, there has been a growing interest in the use of medicinal plants and phytochemicals as potential treatments for acne vulgaris. This condition, characterized by chronic inflammation, predominantly affects adolescents and young adults. Conventional treatment typically targets the key factors contributing [...] Read more.

In recent years, there has been a growing interest in the use of medicinal plants and phytochemicals as potential treatments for acne vulgaris. This condition, characterized by chronic inflammation, predominantly affects adolescents and young adults. Conventional treatment typically targets the key factors contributing to its development: the proliferation of Cutibacterium acnes and the associated inflammation. However, these treatments often involve the use of potent drugs. As a result, the exploration of herbal medicine as a complementary approach has emerged as a promising strategy. By harnessing the therapeutic properties of medicinal plants and phytochemicals, it may be possible to address acne vulgaris while minimizing the reliance on strong drugs. This approach not only offers potential benefits for individuals seeking alternative treatments but also underscores the importance of natural remedies of plant origin in dermatological care. The primary aim of this study was to assess the antimicrobial, antioxidant, and anti-inflammatory properties of plants and their phytochemical constituents in the management of mild acne vulgaris. A comprehensive search of scientific databases was conducted from 2018 to September 2023. The findings of this review suggest that medicinal plants and their phytochemical components hold promise as treatments for mild acne vulgaris. However, it is crucial to note that further research employing high-quality evidence and standardized methodologies is essential to substantiate their efficacy and safety profiles. Full article

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23 pages, 3033 KiB

Open AccessReview

Recent Advancements in Metallic Au- and Ag-Based Chitosan Nanocomposite Derivatives for Enhanced Anticancer Drug Delivery

by Mahmoud A. El-Meligy, Eman M. Abd El-Monaem, Abdelazeem S. Eltaweil, Mohamed S. Mohy-Eldin, Zyta M. Ziora, Abolfazl Heydari and Ahmed M. Omer

Molecules 2024, 29(10), 2393; https://doi.org/10.3390/molecules29102393 - 19 May 2024

Cited by 5 | Viewed by 2093

Abstract

The rapid advancements in nanotechnology in the field of nanomedicine have the potential to significantly enhance therapeutic strategies for cancer treatment. There is considerable promise for enhancing the efficacy of cancer therapy through the manufacture of innovative nanocomposite materials. Metallic nanoparticles have been [...] Read more.

The rapid advancements in nanotechnology in the field of nanomedicine have the potential to significantly enhance therapeutic strategies for cancer treatment. There is considerable promise for enhancing the efficacy of cancer therapy through the manufacture of innovative nanocomposite materials. Metallic nanoparticles have been found to enhance the release of anticancer medications that are loaded onto them, resulting in a sustained release, hence reducing the dosage required for drug administration and preventing their buildup in healthy cells. The combination of nanotechnology with biocompatible materials offers new prospects for the development of advanced therapies that exhibit enhanced selectivity, reduced adverse effects, and improved patient outcomes. Chitosan (CS), a polysaccharide possessing distinct physicochemical properties, exhibits favorable attributes for controlled drug delivery due to its biocompatibility and biodegradability. Chitosan nanocomposites exhibit heightened stability, improved biocompatibility, and prolonged release characteristics for anticancer medicines. The incorporation of gold (Au) nanoparticles into the chitosan nanocomposite results in the manifestation of photothermal characteristics, whereas the inclusion of silver (Ag) nanoparticles boosts the antibacterial capabilities of the synthesized nanocomposite. The objective of this review is to investigate the recent progress in the utilization of Ag and Au nanoparticles, or a combination thereof, within a chitosan matrix or its modified derivatives for the purpose of anticancer drug delivery. The research findings for the potential of a chitosan nanocomposite to deliver various anticancer drugs, such as doxorubicin, 5-Fluroacil, curcumin, paclitaxel, and 6-mercaptopurine, were investigated. Moreover, various modifications carried out on the chitosan matrix phase and the nanocomposite surfaces to enhance targeting selectivity, loading efficiency, and pH sensitivity were highlighted. In addition, challenges and perspectives that could motivate further research related to the applications of chitosan nanocomposites in cancer therapy were summarized. Full article

(This article belongs to the Special Issue Nanomaterials for Advanced Biomedical Applications, 2nd Edition)

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19 pages, 9493 KiB

Open AccessArticle

IrO₂ Oxygen Evolution Catalysts Prepared by an Optimized Photodeposition Process on TiO₂ Substrates

by Angeliki Banti, Christina Zafeiridou, Michail Charalampakis, Olga-Niki Spyridou, Jenia Georgieva, Vasileios Binas, Efrosyni Mitrousi and Sotiris Sotiropoulos

Molecules 2024, 29(10), 2392; https://doi.org/10.3390/molecules29102392 - 19 May 2024

Viewed by 2620

Abstract

Preparing high-performance oxygen evolution reaction (OER) catalysts with low precious metal loadings for water electrolysis applications (e.g., for green hydrogen production) is challenging and requires electrically conductive, high-surface-area, and stable support materials. Combining the properties of stable TiO₂ with those of active [...] Read more.

Preparing high-performance oxygen evolution reaction (OER) catalysts with low precious metal loadings for water electrolysis applications (e.g., for green hydrogen production) is challenging and requires electrically conductive, high-surface-area, and stable support materials. Combining the properties of stable TiO₂ with those of active iridium oxide, we synthesized highly active electrodes for OER in acidic media. TiO₂ powders (both commercially available Degussa P-25^® and hydrothermally prepared in the laboratory from TiOSO₄, either as received/prepared or following ammonolysis to be converted to titania black), were decorated with IrO₂ by UV photodeposition from Ir(III) aqueous solutions of varied methanol scavenger concentrations. TEM, EDS, FESEM, XPS, and XRD measurements demonstrate that the optimized version of the photodeposition preparation method (i.e., with no added methanol) leads to direct deposition of well-dispersed IrO₂ nanoparticles. The electroactive surface area and electrocatalytic performance towards OER of these catalysts have been evaluated by cyclic voltammetry (CV), Linear Sweep Voltammetry (LSV), and Electrochemical Impedance Spectroscopy (EIS) in 0.1 M HClO₄ solutions. All TiO₂-based catalysts exhibited better mass-specific (as well as intrinsic) OER activity than commercial unsupported IrO₂, with the best of them (IrO₂ on Degussa P-25^® ΤiO₂ and laboratory-made TiO₂ black) showing 100 mAmg_Ir⁻¹ at an overpotential of η = 243 mV. Chronoamperometry (CA) experiments also proved good medium-term stability of the optimum IrO₂/TiO₂ electrodes during OER. Full article

(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Nanomaterials for Electrochemical Energy Production and Storage)

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19 pages, 20621 KiB

Open AccessArticle

The Preparation and Contact Drying Performance of Encapsulated Microspherical Composite Sorbents Based on Fly Ash Cenospheres

by Elena V. Fomenko, Natalia N. Anshits, Leonid A. Solovyov, Vasily F. Shabanov and Alexander G. Anshits

Molecules 2024, 29(10), 2391; https://doi.org/10.3390/molecules29102391 - 19 May 2024

Cited by 1 | Viewed by 916

Abstract

Sorption technologies are essential for various industries because they provide product quality and process efficiency. New encapsulated microspherical composite sorbents have been developed for resource-saving contact drying of thermolabile materials, particularly grain and seeds of crops. Magnesium sulfate, known for its high water [...] Read more.

Sorption technologies are essential for various industries because they provide product quality and process efficiency. New encapsulated microspherical composite sorbents have been developed for resource-saving contact drying of thermolabile materials, particularly grain and seeds of crops. Magnesium sulfate, known for its high water capacity, fast sorption kinetics, and easy regeneration, was used as an active moisture sorption component. To localize the active component, porous carriers with an accessible internal volume and a perforated glass–crystalline shell were used. These carriers were created by acid etching of cenospheres with different structures isolated from fly ash. The amount of magnesium sulfate included in the internal volume of the microspherical carrier was 38 wt % for cenospheres with ring structures and 26 wt % for cenospheres with network structures. Studies of the moisture sorption properties of composite sorbents on wheat seeds have shown that after 4 h of contact drying the moisture content of wheat decreases from 22.5 to 14.9–15.5 wt %. Wheat seed germination after sorption drying was 95 ± 2%. The advantage of composite sorbents is the encapsulation of the desiccant in the inner volume of perforated cenospheres, which prevents its entrainment and contamination and provides easy separation and stable sorption capacity in several cycles. Full article

(This article belongs to the Section Materials Chemistry)

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44 pages, 15060 KiB

Open AccessReview

Synthesis of Fluorinated Nucleosides/Nucleotides and Their Antiviral Properties

by Yugandhar Kothapalli, Ransom A. Jones, Chung K. Chu and Uma S. Singh

Molecules 2024, 29(10), 2390; https://doi.org/10.3390/molecules29102390 - 19 May 2024

Cited by 1 | Viewed by 3011

Abstract

The FDA has approved several drugs based on the fluorinated nucleoside pharmacophore, and numerous drugs are currently in clinical trials. Fluorine-containing nucleos(t)ides offer significant antiviral and anticancer activity. The insertion of a fluorine atom, either in the base or sugar of nucleos(t)ides, alters [...] Read more.

The FDA has approved several drugs based on the fluorinated nucleoside pharmacophore, and numerous drugs are currently in clinical trials. Fluorine-containing nucleos(t)ides offer significant antiviral and anticancer activity. The insertion of a fluorine atom, either in the base or sugar of nucleos(t)ides, alters its electronic and steric parameters and transforms the lipophilicity, pharmacodynamic, and pharmacokinetic properties of these moieties. The fluorine atom restricts the oxidative metabolism of drugs and provides enzymatic metabolic stability towards the glycosidic bond of the nucleos(t)ide. The incorporation of fluorine also demonstrates additional hydrogen bonding interactions in receptors with enhanced biological profiles. The present article discusses the synthetic methodology and antiviral activities of FDA-approved drugs and ongoing fluoro-containing nucleos(t)ide drug candidates in clinical trials. Full article

(This article belongs to the Special Issue Nucleoside and Nucleotide Analogues: Chemical Synthesis and Applications)

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17 pages, 4102 KiB

Open AccessArticle

A Squaramide-Based Organocatalyst as a Novel Versatile Chiral Solvating Agent for Carboxylic Acids

by Fabio Spiaggia, Gloria Uccello Barretta, Anna Iuliano, Carlo Baldassari, Federica Aiello and Federica Balzano

Molecules 2024, 29(10), 2389; https://doi.org/10.3390/molecules29102389 - 19 May 2024

Viewed by 1034

Abstract

A squaramide-based organocatalyst for asymmetric Michael reactions has been tested as a chiral solvating agent (CSA) for 26 carboxylic acids and camphorsulfonic acid, encompassing amino acid derivatives, mandelic acid, as well as some of its analogs, propionic acids like profens (ketoprofen and ibuprofen), [...] Read more.

A squaramide-based organocatalyst for asymmetric Michael reactions has been tested as a chiral solvating agent (CSA) for 26 carboxylic acids and camphorsulfonic acid, encompassing amino acid derivatives, mandelic acid, as well as some of its analogs, propionic acids like profens (ketoprofen and ibuprofen), butanoic acids and others. In many cases remarkably high enantiodifferentiations at ¹H, ¹³C and ¹⁹F nuclei were observed. The interaction likely involves a proton transfer from the acidic substrates to the tertiary amine sites of the organocatalyst, thus allowing for pre-solubilization of the organocatalyst (when a chloroform solution of the substrate is employed) or the simultaneous solubilization of both the catalyst and the substrate. DOSY experiments were employed to evaluate whether the catalyst–substrate ionic adduct was a tight one or not. ROESY experiments were employed to investigate the role of the squaramide unit in the adduct formation. A mechanism of interaction was proposed in accordance with the literature data. Full article

(This article belongs to the Section Organic Chemistry)

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21 pages, 3807 KiB

Open AccessReview

Anticancer Potential of Indole Phytoalexins and Their Analogues

by Martina Zigová, Radka Michalková and Ján Mojžiš

Molecules 2024, 29(10), 2388; https://doi.org/10.3390/molecules29102388 - 19 May 2024

Viewed by 1226

Abstract

Indole phytoalexins, found in economically significant Cruciferae family plants, are synthesized in response to pathogen attacks or stress, serving as crucial components of plant defense mechanisms against bacterial and fungal infections. Furthermore, recent research indicates that these compounds hold promise for improving human [...] Read more.

Indole phytoalexins, found in economically significant Cruciferae family plants, are synthesized in response to pathogen attacks or stress, serving as crucial components of plant defense mechanisms against bacterial and fungal infections. Furthermore, recent research indicates that these compounds hold promise for improving human health, particularly in terms of potential anticancer effects that have been observed in various studies. Since our last comprehensive overview in 2016 focusing on the antiproliferative effects of these substances, brassinin and camalexin have been the most extensively studied. This review analyses the multifaceted pharmacological effects of brassinin and camalexin, highlighting their anticancer potential. In this article, we also provide an overview of the antiproliferative activity of new synthetic analogs of indole phytoalexins, which were synthesized and tested at our university with the aim of enhancing efficacy compared to the parent compound. Full article

(This article belongs to the Special Issue Plant Bioactive Compounds in Pharmaceuticals)

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16 pages, 7990 KiB

Open AccessArticle

Sequestration of an Azo Dye by a Potential Biosorbent: Characterization of Biosorbent, Adsorption Isotherm and Adsorption Kinetic Studies

by Bharti Gaur, Jyoti Mittal, Syed Ansar Ali Shah, Alok Mittal and Richard T. Baker

Molecules 2024, 29(10), 2387; https://doi.org/10.3390/molecules29102387 - 19 May 2024

Cited by 4 | Viewed by 896

Abstract

This study explores the detailed characterization of a biosorbent (Hen Feather) and its efficient use in eradicating the azo dye Metanil Yellow (MY) from its aqueous solutions. Effects of a range of experimental parameters, including pH, initial dye concentration, biosorbent dosage and contact [...] Read more.

This study explores the detailed characterization of a biosorbent (Hen Feather) and its efficient use in eradicating the azo dye Metanil Yellow (MY) from its aqueous solutions. Effects of a range of experimental parameters, including pH, initial dye concentration, biosorbent dosage and contact time on the adsorption, were studied. A detailed physical and chemical characterization of the biosorbent was made using SEM, XRD, XPS and FTIR. During the optimization of adsorption parameters, the highest dye uptake of almost 99% was recorded at pH 2, dye concentration 2 × 10⁻⁵ M, 0.05 g of biosorbent and a contact period of 75 min. Various adsorption isotherm models were studied to gather different adsorption and thermodynamic parameters. The linearity of the Langmuir, Freundlich and D-R adsorption isotherms indicate homogeneous, multilayer chemisorption with high adsorption affinity between the dye and biosorbent. Values of the changes in the Gibbs free energy (ΔG°) and the enthalpy (ΔH°) of the adsorption process have been calculated, these values indicate that it is a spontaneous and endothermic process. Kinetics of the adsorption were also measured, and it was established that the adsorption of MY over Hen Feather follows a pseudo-second-order kinetic model at temperatures 30, 40 and 50 °C. The findings of this investigation clearly indicate that the studied biosorbent exhibits a high affinity towards the dye (MY), and it can be effectively, economically and efficiently used to sequestrate and eradicate MY from its aqueous solutions. Full article

(This article belongs to the Special Issue Chemistry of Materials for Energy and Environmental Sustainability)

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10 pages, 3931 KiB

Open AccessArticle

An Aggregation-Induced Fluorescence Probe for Detection H₂S and Its Application in Cell Imaging

by Xin-Hui Tang, Hao-Na Zhang, Wen-Ling Wang and Qing-Ming Wang

Molecules 2024, 29(10), 2386; https://doi.org/10.3390/molecules29102386 - 19 May 2024

Cited by 3 | Viewed by 1158

Abstract

Monitoring hydrogen sulfide (H₂S) in living organisms is very important because H₂S acts as a regulator in many physiological and pathological processes. Upregulation of endogenous H₂S concentration has been shown to be closely related to the occurrence [...] Read more.

Monitoring hydrogen sulfide (H₂S) in living organisms is very important because H₂S acts as a regulator in many physiological and pathological processes. Upregulation of endogenous H₂S concentration has been shown to be closely related to the occurrence and development of tumors, atherosclerosis, neurodegenerative diseases and diabetes. Herin, a novel fluorescent probe HND with aggregation-induced emission was designed. Impressively, HND exhibited a high selectivity, fast response (1 min) and low detection limit (0.61 μM) for H₂S in PBS buffer (10 mM, pH = 7.42). Moreover, the reaction mechanism between HND and H₂S was conducted by Job’s plot, HR-MS, and DFT. In particular, HND was successfully employed to detect H₂S in HeLa cells. Full article

(This article belongs to the Section Analytical Chemistry)

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20 pages, 4471 KiB

Open AccessArticle

Ultrasound-Assisted Extraction of Phenolic Compounds from Celtuce (Lactuca sativa var. augustana) Leaves Using Natural Deep Eutectic Solvents (NADES): Process Optimization and Extraction Mechanism Research

by Shanshan Li, Guangyu Wang, Junjie Zhao, Penghui Ou, Qingping Yao and Wei Wang

Molecules 2024, 29(10), 2385; https://doi.org/10.3390/molecules29102385 - 19 May 2024

Viewed by 1513

Abstract

Natural deep eutectic solvents (NADESs), as emerging green solvents, can efficiently extract natural products from natural resources. However, studies on the extraction of phenolic compounds from celtuce (Lactuca sativa var. augustana) leaves (CLs) by NADESs are still lacking. This study screened [...] Read more.

Natural deep eutectic solvents (NADESs), as emerging green solvents, can efficiently extract natural products from natural resources. However, studies on the extraction of phenolic compounds from celtuce (Lactuca sativa var. augustana) leaves (CLs) by NADESs are still lacking. This study screened the NADES L-proline-lactic acid (Pr-LA), combined it with ultrasound-assisted extraction (UAE) to extract phenolic compounds from CLs, and conducted a comparative study on the extraction effect with traditional extraction solvents. Both SEM and FT-IR confirmed that Pr-LA can enhance the degree of fragmentation of cell structures and improve the extraction rate of phenolic compounds. Molecular dynamics simulation results show that Pr-LA can improve the solubility of phenolic compounds and has stronger hydrogen bonds and van der Waals interactions with phenolic compounds. Single-factor and Box–Behnken experiments optimized the process parameters for the extraction of phenolic compounds from CLs. The second-order kinetic model describes the extraction process of phenolic compounds from CLs under optimal process parameters and provides theoretical guidance for actual industrial production. This study not only provides an efficient and green method for extracting phenolic compounds from CLs but also clarifies the mechanism of improved extraction efficiency, which provides a basis for research on the NADES extraction mechanism. Full article

(This article belongs to the Special Issue Natural Deep Eutectic Solvents and Other Green Solvents: The New Lights for Extraction and Valorization of Bioactive Phytochemical Compounds)

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16 pages, 4325 KiB

Open AccessArticle

Metal–Organic Framework-Capped Gold Nanorod Hybrids for Combinatorial Cancer Therapy

by Chong Zhao, Hongxiang Liu, Sijun Huang, Yi Guo and Li Xu

Molecules 2024, 29(10), 2384; https://doi.org/10.3390/molecules29102384 - 18 May 2024

Viewed by 1424

Abstract

Recently, nanomaterials have attracted extensive attention in cancer-targeting therapy and as drug delivery vehicles owing to their unique surface and size properties. Multifunctional combinations of nanomaterials have become a research hotspot as researchers aim to provide a full understanding of their nanomaterial characteristics. [...] Read more.

Recently, nanomaterials have attracted extensive attention in cancer-targeting therapy and as drug delivery vehicles owing to their unique surface and size properties. Multifunctional combinations of nanomaterials have become a research hotspot as researchers aim to provide a full understanding of their nanomaterial characteristics. In this study, metal–organic framework-capped gold nanorod hybrids were synthesized. Our research explored their ability to kill tumor cells by locally increasing the temperature via photothermal conclusion. The specific peroxidase-like activity endows the hybrids with the ability to disrupt the oxidative balance in vitro. Simultaneously, chemotherapeutic drugs are administered and delivered by loading and transportation for effective combinatorial cancer treatment, thereby enhancing the curative effect and reducing the unpredictable toxicity and side effects of large doses of chemotherapeutic drugs. These studies can improve combinatorial cancer therapy and enhance cancer treatment. Full article

(This article belongs to the Special Issue Advances in Nanomaterials for Biomedical Applications)

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13 pages, 4428 KiB

Open AccessArticle

Photocatalytic Deposition of Au Nanoparticles on Ti₃C₂T_x MXene Substrates for Surface-Enhanced Raman Scattering

by Zhi Yang, Lu Yang, Yucun Liu and Lei Chen

Molecules 2024, 29(10), 2383; https://doi.org/10.3390/molecules29102383 - 18 May 2024

Cited by 2 | Viewed by 1748

Abstract

Surface-enhanced Raman scattering (SERS) is a promising technique for sensitive detection. The design and optimization of plasma-enhanced structures for SERS applications is an interesting challenge. In this study, we found that the SERS activity of MXene (Ti₃C₂T_x) [...] Read more.

Surface-enhanced Raman scattering (SERS) is a promising technique for sensitive detection. The design and optimization of plasma-enhanced structures for SERS applications is an interesting challenge. In this study, we found that the SERS activity of MXene (Ti₃C₂T_x) can be improved by adding Au nanoparticles (NPs) in a simple photoreduction process. Fluoride-salt-etched MXene was deposited by drop-casting on a glass slide, and Au NPs were formed by the photocatalytic growth of gold(III) chloride trihydrate solutions under ultraviolet (UV) irradiation. The Au–MXene substrate formed by Au NPs anchored on the Ti₃C₂T_x sheet produced significant SERS through the synergistic effect of chemical and electromagnetic mechanisms. The structure and size of the Au-decorated MXene depended on the reaction time. When the MXene films were irradiated with a large number of UV photons, the size of the Au NPs increased. Hot spots were formed in the nanoscale gaps between the Au NPs, and the abundant surface functional groups of the MXene effectively adsorbed and interacted with the probe molecules. Simultaneously, as a SERS substrate, the proposed Au–MXene composite exhibited a wider linear range of 10⁻⁴–10⁻⁹ mol/L for detecting carbendazim. In addition, the enhancement factor of the optimized SERS substrate Au–MXene was 1.39 × 10⁶, and its relative standard deviation was less than 13%. This study provides a new concept for extending experimental strategies to further improve the performance of SERS. Full article

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

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15 pages, 9104 KiB

Open AccessArticle

Understanding Chromium Slag Recycling with Sintering–Ironmaking Processes: Influence of Cr₂O₃ on the Sinter Microstructure and Mechanical Properties of the Silico–Ferrite of Calcium and Aluminum (SFCA)

by Ju Xu, Guojun Ma, Mengke Liu, Xiang Zhang, Dingli Zheng, Tianyu Du, Yanheng Luo and Wei Zhang

Molecules 2024, 29(10), 2382; https://doi.org/10.3390/molecules29102382 - 18 May 2024

Viewed by 1189

Abstract

Chromium slag is a solid waste of chromium salt production, which contains highly toxic Cr(VI) and significant amounts of valuable metals, such as Fe and Cr. Recycling chromium slag as a raw sintering material in sintering–ironmaking processes can simultaneously reduce toxic Cr(VI) and [...] Read more.

Chromium slag is a solid waste of chromium salt production, which contains highly toxic Cr(VI) and significant amounts of valuable metals, such as Fe and Cr. Recycling chromium slag as a raw sintering material in sintering–ironmaking processes can simultaneously reduce toxic Cr(VI) and recover valuable metals. A micro-sintering experiment, compressive strength test, microhardness test, and first-principles calculation are performed to investigate the influence of Cr₂O₃ on the sintering microstructure and mechanical properties of the silico-ferrite of calcium and aluminum (SFCA) in order to understand the basis of the sintering process with chromium slag addition. The results show that the microstructure of SFCA changes from blocky to interwoven, with further increasing Cr₂O₃ content from 0 wt% to 3 wt%, and transforms to blocky with Cr₂O₃ content increasing to 5 wt%. Cr₂O₃ reacts with Fe₂O₃ to form (Fe_1−xCr_x)₂O₃ (0 ≤ x ≤ 1), which participates in forming SFCA. With the increase in Cr doping concentrations, the hardness of SFCA first decreases and then increases, and the toughness increases. When Cr₂O₃ content increases from 0 wt% to 3 wt%, the SFCA microhardness decreases and the compressive strength of the sintered sample increases. Further increasing Cr₂O₃ contents to 5 wt%, the SFCA microhardness increases, and the compressive strength of sintered sample decreases. Full article

(This article belongs to the Topic Computational Chemistry in Metallurgy, Materials and Energy)

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16 pages, 5642 KiB

Open AccessArticle

Functionalized Ionic Liquids-Modified Metal–Organic Framework Material Boosted the Enzymatic Performance of Lipase

by Liran Ji, Wei Zhang, Yifei Zhang, Binbin Nian and Yi Hu

Molecules 2024, 29(10), 2381; https://doi.org/10.3390/molecules29102381 - 18 May 2024

Cited by 1 | Viewed by 1498

Abstract

The development of immobilized enzymes with high activity and stability is critical. Metal–organic frameworks (MOFs) have attracted much academic and industrial interest in the field of enzyme immobilization due to their unique properties. In this study, the amino-functionalized ionic liquid (NIL)-modified metal–organic framework [...] Read more.

The development of immobilized enzymes with high activity and stability is critical. Metal–organic frameworks (MOFs) have attracted much academic and industrial interest in the field of enzyme immobilization due to their unique properties. In this study, the amino-functionalized ionic liquid (NIL)-modified metal–organic framework (UiO-66-NH₂) was prepared to immobilize Candida rugosa lipase (CRL), using dialdehyde starch (DAS) as the cross-linker. The results of the Fourier transform infrared (FT-IR) spectra, X-ray powder diffraction (XRD), and scanning electronic microscopy (SEM) confirmed that the NIL was successfully grafted to UiO-66-NH₂. The CRL immobilized on NIL-modified UiO-66-NH₂ (UiO-66-NH₂-NIL-DAS@CRL) exhibited satisfactory activity recovery (79.33%), stability, reusability, and excellent organic solvent tolerance. The research results indicated that ionic liquid-modified UiO-66-NH₂ had practical potential for application in enzyme immobilization. Full article

(This article belongs to the Special Issue Modern Trends of Biocatalysis in Organic Chemistry and Enzyme Engineering–2nd Edition)

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18 pages, 3204 KiB

Open AccessReview

Progress on the Synthesis of the Aromathecin Family of Compounds: An Overview

by Takashi Nishiyama, Shota Mizuno, Yuhzo Hieda and Tominari Choshi

Molecules 2024, 29(10), 2380; https://doi.org/10.3390/molecules29102380 - 18 May 2024

Viewed by 855

Abstract

We present a systematic review of the methods developed for the synthesis of the aromathecin family of compounds (benz[6,7]indolizino[1,2-b]quinolin-11(13H)-ones) and their derivatives. These methods can be broadly classified into four categories based on the construction of pentacyclic structures: Category [...] Read more.

We present a systematic review of the methods developed for the synthesis of the aromathecin family of compounds (benz[6,7]indolizino[1,2-b]quinolin-11(13H)-ones) and their derivatives. These methods can be broadly classified into four categories based on the construction of pentacyclic structures: Category 1: by constructing a pyridone moiety (D-ring) on the pyrroloquinoline ring (A/B/C-ring), Category 2: by constructing a pyridine moiety (B-ring) on the pyrroloisoquinolone ring (C/D/E-ring), Category 3: by constructing an indolizidinone moiety (C/D-ring) in a tandem reaction, and Category 4: by constructing a pyrrolidine moiety (C-ring) on the isoquinolone ring (D/E-ring). Full article

(This article belongs to the Special Issue Recent Advances in the Organic Synthesis of Bioactive Compounds)

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18 pages, 3211 KiB

Open AccessArticle

The Optimization of Pair Distribution Functions for the Evaluation of the Degree of Disorder and Physical Stability in Amorphous Solids

by Zhihui Yuan, Zunhua Li, Jie Luo, Asad Nawaz, Bowen Zhang and Wubliker Dessie

Molecules 2024, 29(10), 2379; https://doi.org/10.3390/molecules29102379 - 18 May 2024

Viewed by 884

Abstract

The amorphous form of poorly soluble drugs is physically unstable and prone to crystallization, resulting in decreased solubility and bioavailability. However, the conventional accelerated stability test for amorphous drugs is time-consuming and inaccurate. Therefore, there is an urgent need to develop rapid and [...] Read more.

The amorphous form of poorly soluble drugs is physically unstable and prone to crystallization, resulting in decreased solubility and bioavailability. However, the conventional accelerated stability test for amorphous drugs is time-consuming and inaccurate. Therefore, there is an urgent need to develop rapid and accurate stability assessment technology. This study used the antitumor drug nilotinib free base as a model drug. The degree of disorder and physical stability in the amorphous form was assessed by applying the pair distribution function (PDF) and principal component analysis (PCA) methods based on powder X-ray diffraction (PXRD) data. Specifically, the assessment conditions, such as the PDF interatomic distance range, PXRD detector type, and PXRD diffraction angle range were also optimized. The results showed that more reliable PCA data could be obtained when the PDF interatomic distance range was 0–15 Å. When the PXRD detector was a semiconductor-type detector, the PDF data obtained were more accurate than other detectors. When the PXRD diffraction angle range was 5–40°, the intermolecular arrangement of the amorphous drugs could be accurately predicted. Finally, the accelerated stability test also showed that under the above-optimized conditions, this method could accurately and rapidly assess the degree of disorder and physical stability in the amorphous form of drugs, which has obvious advantages compared with the accelerated stability test. 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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