Molecules

21 pages, 12034 KiB

Open AccessArticle

Broad Spectral Response FeOOH/BiO_2−x Photocatalyst with Efficient Charge Transfer for Enhanced Photo-Fenton Synergistic Catalytic Activity

by Pengfei Wu, Yufei Qin, Mengyuan Gao, Rui Zheng, Yixin Zhang, Xinli Li, Zhaolong Liu, Yingkun Zhang, Zhen Cao and Qingling Liu

Molecules 2024, 29(4), 919; https://doi.org/10.3390/molecules29040919 - 19 Feb 2024

Cited by 2 | Viewed by 1381

Abstract

In this work, to promote the separation of photogenerated carriers, prevent the catalyst from photo-corrosion, and improve the photo-Fenton synergistic degradation of organic pollutants, the coating structure of FeOOH/BiO_2−x rich in oxygen vacancies was successfully synthesized by a facile and environmentally friendly [...] Read more.

In this work, to promote the separation of photogenerated carriers, prevent the catalyst from photo-corrosion, and improve the photo-Fenton synergistic degradation of organic pollutants, the coating structure of FeOOH/BiO_2−x rich in oxygen vacancies was successfully synthesized by a facile and environmentally friendly two-step process of hydrothermal and chemical deposition. Through a series of degradation activity tests of synthesized materials under different conditions, it was found that FeOOH/BiO_2−x demonstrated outstanding organic pollutant degradation activity under visible and near-infrared light when hydrogen peroxide was added. After 90 min of reaction under photo-Fenton conditions, the degradation rate of Methylene Blue by FeOOH/BiO_2−x was 87.4%, significantly higher than the degradation efficiency under photocatalysis (60.3%) and Fenton (49.0%) conditions. The apparent rate constants of FeOOH/BiO_2−x under photo-Fenton conditions were 2.33 times and 3.32 times higher than photocatalysis and Fenton catalysis, respectively. The amorphous FeOOH was tightly coated on the layered BiO_2−x, which significantly increased the specific surface area and the number of active sites of the composites, and facilitated the improvement of the separation efficiency of the photogenerated carriers and the prevention of photo-corrosion of BiO_2−x. The analysis of the mechanism of photo-Fenton synergistic degradation clarified that ·OH, h⁺, and ·O₂⁻ are the main active substances involved in the degradation of pollutants. The optimal degradation conditions were the addition of the FeOOH/BiO_2−x composite catalyst loaded with 20% Fe at a concentration of 0.5 g/L, the addition of hydrogen peroxide at a concentration of 8 mM, and an initial pH of 4. This outstanding catalytic system offers a fresh approach to the creation and processing of iron-based photo-Fenton catalysts by quickly and efficiently degrading various organic contaminants. Full article

(This article belongs to the Special Issue Advanced Photocatalysts for Energy Conversion and Environmental Applications, 2nd Edition)

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12 pages, 1982 KiB

Open AccessArticle

Heterogeneous Brønsted Catalysis in the Solvent-Free and Multigram-Scale Synthesis of Polyalcohol Acrylates: The Case Study of Trimethylolpropane Triacrylate

by Massimo Melchiorre, Maria E. Cucciolito, Roberto Esposito, Simone Silvestro and Francesco Ruffo

Molecules 2024, 29(4), 918; https://doi.org/10.3390/molecules29040918 - 19 Feb 2024

Viewed by 1431

Abstract

This article presents a thorough investigation into the synthesis of trimethylolpropane triacrylate (TMPTA) via the esterification reaction of trimethylolpropane (TMP) with acrylic acid using Amberlite™ 120 IR (H⁺), Amberlyst^® 15, and Dowex™ 50WX8 resins as heterogeneous catalysts. Preliminary comparative tests [...] Read more.

This article presents a thorough investigation into the synthesis of trimethylolpropane triacrylate (TMPTA) via the esterification reaction of trimethylolpropane (TMP) with acrylic acid using Amberlite™ 120 IR (H⁺), Amberlyst^® 15, and Dowex™ 50WX8 resins as heterogeneous catalysts. Preliminary comparative tests explored the impact of air flow on water removal during the reaction and different acid-to-alcohol molar ratios (3:1, 6:1, or 9:1 mol:mol). The findings revealed that introducing air significantly enhances TMPTA yield and -OH group conversion, particularly at a 6:1 acid-to-alcohol molar ratio. Based on cost considerations, Amberlite™ 120 IR (H⁺) was selected as the preferred catalyst for further optimization. This included evaluating the effect of catalyst loading (10%, 5.0%, and 2.5% w/w_tot) and assessing the impact of a pre-drying process on resin efficiency. The study concluded that optimal conditions did not necessitate drying, requiring 120 °C, a catalyst loading of 10% w/w_tot, a 4 h reaction time, an acid:alcohol ratio of 6:1 mol:mol, the presence of MEHQ (0.1% mol/mol_AA), and air bubbling at 6 ± 1 Nl/h. Catalyst recycling was effectively implemented with a slight reduction in catalytic activity over consecutive runs. Furthermore, the study explored a scaled-up system with a mechanical stirrer, demonstrating the potential for multi-hundred grams scale-up. Considerations for optimizing the air flow stripping system are also highlighted. In summary, this study provides valuable insights into designing and optimizing the esterification process for TMPTA synthesis, laying the foundation for potential industrial applications. Full article

(This article belongs to the Special Issue Research on Heterogeneous Catalysis)

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15 pages, 1876 KiB

Open AccessArticle

Bioactive Potential of Carrot-Based Products Enriched with Lactobacillus plantarum

by Monica Boev, Cristina Stănescu, Mihaela Turturică, Mihaela Cotârleţ, Denisa Batîr-Marin, Nicoleta Maftei, Carmen Chiţescu, Leontina Grigore-Gurgu, Vasilica Barbu, Elena Enachi and Elena Lăcrămioara Lisă

Molecules 2024, 29(4), 917; https://doi.org/10.3390/molecules29040917 - 19 Feb 2024

Viewed by 1500

Abstract

The primary goal of this study was to generate different kinds of functional products based on carrots that were supplemented with lactic acid bacteria. The fact that carrots (Daucus carota sp.) rank among the most popular vegetables in our country led to [...] Read more.

The primary goal of this study was to generate different kinds of functional products based on carrots that were supplemented with lactic acid bacteria. The fact that carrots (Daucus carota sp.) rank among the most popular vegetables in our country led to the convergence of the research aim. Their abundance of bioactive compounds, primarily polyphenols, flavonoids, and carotenoids, offers numerous health benefits. Among the obtained products, the freeze-dried carrot powder (FDCP) variation presented the highest concentrations of total carotenoids (TCs) and β-carotene (BC) of 26.977 ± 0.13 mg/g DW and 22.075 ± 0.14 mg/g DW, respectively. The amount of total carotenoids and β-carotene significantly increased with the addition of the selected lactic acid bacteria (LAB) for most of the samples. In addition, a slight increase in the antioxidant activity compared with the control sample for the FDCP variant, with the highest value of 91.74%, was observed in these functional food products. The content of polyphenolic compounds varied from 0.044 to 0.091 mg/g DW, while the content of total flavonoids varied from 0.03 to 0.66 mg/g DW. The processing method had an impact on the population of L. plantarum that survived, as indicated by the viability of bacterial cells in all the analyzed products. The chromatographic analysis through UHPLC-MS/MS further confirmed the abundance of the bioactive compounds and their corresponding derivatives by revealing 19 different compounds. The digestibility study indicated that carotenoid compounds from carrots followed a rather controlled release. The carrot-based products enriched with Lactobacillus plantarum can be considered newly functional developed products based on their high content of biologically active compounds with beneficial effects upon the human body. Furthermore, these types of products could represent innovative products for every related industry such as the food, pharmaceutical, and cosmeceutical industries, thus converging a new strategy to improve the health of consumers or patients. Full article

(This article belongs to the Section Food Chemistry)

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12 pages, 1308 KiB

Open AccessArticle

Study on the Effect of Cations on the Surface Energy of Nano-SiO₂ Particles for Oil/Gas Exploration and Development Based on the Density Functional Theory

by Jun Ni, Lei Zhang, Chengjun Wang, Weibo Wang and Ge Jin

Molecules 2024, 29(4), 916; https://doi.org/10.3390/molecules29040916 - 19 Feb 2024

Viewed by 1155

Abstract

Although nano SiO₂ exhibits excellent application potential in the field of oil and gas exploration and development, such as drilling fluid, enhanced oil/gas recovery, etc., it is prone to agglomeration and loses its effectiveness due to the action of cations in saline [...] Read more.

Although nano SiO₂ exhibits excellent application potential in the field of oil and gas exploration and development, such as drilling fluid, enhanced oil/gas recovery, etc., it is prone to agglomeration and loses its effectiveness due to the action of cations in saline environments of oil and gas reservoirs. Therefore, it is crucial to study the mechanism of the change in energy between nano SiO₂ and cations for its industrial application. In this paper, the effect of cations (Na⁺, K⁺, Ca²⁺, and Mg²⁺) on the surface energy of nano SiO₂ particles is investigated from the perspective of molecular motion and electronic change by density functional theory. The results are as follows: Due to the electrostatic interactions, cations can migrate towards the surface of nano SiO₂ particles. During the migration process, monovalent cations are almost unaffected by water molecules, and they can be directly adsorbed on the surface by nano SiO₂ particles. However, when divalent cations migrate from a distance to the surface of nano SiO₂ particles, they can combine with water molecules to create an energy barrier, which can prevent them from moving forward. When divalent cations break through the energy barrier, the electronic kinetic energy between them and nano SiO₂ particles changes more strongly, and the electrons carried by them are more likely to break through the edge of the atomic nucleus and undergo charge exchange with nano SiO₂ particles. The change in interaction energy is more intense, which can further disrupt the configuration stability of nano SiO₂. The interaction energy between cations and nano SiO₂ particles mainly comes from electrostatic energy, followed by Van der Waals energy. From the degree of influence of four cations on nano SiO₂ particles, the order from small to large is as follows: K⁺ < Na⁺ < Mg²⁺ < Ca²⁺. The research results can provide a theoretical understanding of the interaction between nano SiO₂ particles and cations during the application of nano SiO₂ in the field of oil and gas exploration and development. Full article

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16 pages, 5336 KiB

Open AccessArticle

Enzymatic Synthesis of Structured Lipids Enriched with Medium- and Long-Chain Triacylglycerols via Pickering Emulsion-Assisted Interfacial Catalysis: A Preliminary Exploration

by Zhe Dong, Ziheng Cui, Jun Jin, Xinyi Cheng, Gangcheng Wu, Xingguo Wang and Qingzhe Jin

Molecules 2024, 29(4), 915; https://doi.org/10.3390/molecules29040915 - 19 Feb 2024

Cited by 1 | Viewed by 1365

Abstract

Medium- and long-chain triacylglycerol (MLCT), as a novel functional lipid, is valuable due to its special nutritional properties. Its low content in natural resources and inefficient synthesis during preparation have limited its practical applications. In this study, we developed an effective Pickering emulsion [...] Read more.

Medium- and long-chain triacylglycerol (MLCT), as a novel functional lipid, is valuable due to its special nutritional properties. Its low content in natural resources and inefficient synthesis during preparation have limited its practical applications. In this study, we developed an effective Pickering emulsion interfacial catalysis system (PE system) for the enzymatic synthesis of MLCT by trans-esterification. Lipase NS 40086 served simultaneously as a catalyst and a solid emulsifier to stabilize the Pickering emulsion. Benefitting from the sufficient oil–water interface, the obtained PE system exhibited outstanding catalytic efficiency, achieving 77.5% of MLCT content within 30 min, 26% higher than that of a water-free system. The K_m value (0.259 mM) and activation energy (14.45 kJ mol⁻¹) were 6.8-fold and 1.6-fold lower than those of the water-free system, respectively. The kinetic parameters as well as the molecular dynamics simulation and the tunnel analysis implied that the oil–water interface enhanced the binding between substrate and lipase and thus boosted catalytic efficiency. The conformational changes in the lipase were further explored by FT-IR. This method could give a novel strategy for enhancing lipase activity and the design of efficient catalytic systems to produce added-value lipids. This work will open a new methodology for the enzymatic synthesis of structured lipids. Full article

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43 pages, 48297 KiB

Open AccessArticle

Novel Antineoplastic Inducers of Mitochondrial Apoptosis in Human Cancer Cells

by Andreas J. Kesel

Molecules 2024, 29(4), 914; https://doi.org/10.3390/molecules29040914 - 19 Feb 2024

Viewed by 2294

Abstract

I propose a new strategy to suppress human cancer completely with two entirely new drug compounds exploiting cancer’s Warburg effect characterized by a defective mitochondrial aerobic respiration, substituted by cytosolic aerobic fermentation/glycolysis of D-(+)-glucose into L-(+)-lactic acid. The two essentially new drugs, compound [...] Read more.

I propose a new strategy to suppress human cancer completely with two entirely new drug compounds exploiting cancer’s Warburg effect characterized by a defective mitochondrial aerobic respiration, substituted by cytosolic aerobic fermentation/glycolysis of D-(+)-glucose into L-(+)-lactic acid. The two essentially new drugs, compound 1 [P(op)T(est)162] and compound 3 (PT167), represent new highly symmetric, four-bladed propeller-shaped polyammonium cations. The in vitro antineoplastic highly efficacious drug compound 3 represents a covalent combination of compound 1 and compound 2 (PT166). The intermediate drug compound 2 is an entirely new colchic(in)oid derivative synthesized from colchicine. Compound 2’s structure was determined using X-ray crystallography. Compound 1 and compound 3 were active in vitro versus 60 human cancer cell lines of the National Cancer Institute (NCI) Developmental Therapeutics Program (DTP) 60-cancer cell testing. Compound 1 and compound 3 not only stop the growth of cancer cells to ±0% (cancerostatic effect) but completely kill nearly all 60 cancer cells to a level of almost −100% (tumoricidal effect). Compound 1 and compound 3 induce mitochondrial apoptosis (under cytochrome c release) in all cancer cells tested by (re)activating (in most cancers impaired) p53 function, which results in a decrease in cancer’s dysregulated cyclin D1 and an induction of the cell cycle-halting cyclin-dependent kinase inhibitor p21^Waf1/p21^Cip1. Full article

(This article belongs to the Section Medicinal Chemistry)

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15 pages, 4187 KiB

Open AccessArticle

A Versatile Approach for the Synthesis of Antimicrobial Polymer Brushes on Natural Rubber/Graphene Oxide Composite Films via Surface-Initiated Atom-Transfer Radical Polymerization

by Wenya Zhu, Bangsen Li, Jinrui Liu, Shishu Sun, Yan Zhang, Dashuai Zhang, Chen Li, Tianyi Sun, Huaide Qin, Jianjun Shi and Zaifeng Shi

Molecules 2024, 29(4), 913; https://doi.org/10.3390/molecules29040913 - 19 Feb 2024

Viewed by 1241

Abstract

A simple strategy was adopted for the preparation of an antimicrobial natural rubber/graphene oxide (NR/GO) composite film modified through the use of zwitterionic polymer brushes. An NR/GO composite film with antibacterial properties was prepared using a water-based solution-casting method. The composited GO was [...] Read more.

A simple strategy was adopted for the preparation of an antimicrobial natural rubber/graphene oxide (NR/GO) composite film modified through the use of zwitterionic polymer brushes. An NR/GO composite film with antibacterial properties was prepared using a water-based solution-casting method. The composited GO was dispersed uniformly in the NR matrix and compensated for mechanical loss in the process of modification. Based on the high bromination activity of α–H in the structure of cis-polyisoprene, the composite films were brominated on the surface through the use of N-bromosuccinimide (NBS) under the irradiation of a 40 W tungsten lamp. Polymerization was carried out on the brominated films using sulfobetaine methacrylate (SBMA) as a monomer via surface-initiated atom transfer radical polymerization (SI-ATRP). The NR/GO composite films modified using polymer brushes (PSBMAs) exhibited 99.99% antimicrobial activity for resistance to Escherichia coli and Staphylococcus aureus. A novel polymer modification strategy for NR composite materials was established effectively, and the enhanced antimicrobial properties expand the application prospects in the medical field. Full article

(This article belongs to the Section Macromolecular Chemistry)

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19 pages, 7744 KiB

Open AccessArticle

Levistilide A Exerts a Neuroprotective Effect by Suppressing Glucose Metabolism Reprogramming and Preventing Microglia Polarization Shift: Implications for Parkinson’s Disease

by Mingjie Zhang, Congyan Duan, Weifang Lin, Honghua Wu, Lu Chen, Hong Guo, Minyu Yu, Qi Liu, Yaling Nie, Hong Wang and Shaoxia Wang

Molecules 2024, 29(4), 912; https://doi.org/10.3390/molecules29040912 - 19 Feb 2024

Cited by 1 | Viewed by 1786

Abstract

The microglia, displaying diverse phenotypes, play a significant regulatory role in the development, progression, and prognosis of Parkinson’s disease. Research has established that glycolytic reprogramming serves as a critical regulator of inflammation initiation in pro-inflammatory macrophages. Furthermore, the modulation of glycolytic reprogramming has [...] Read more.

The microglia, displaying diverse phenotypes, play a significant regulatory role in the development, progression, and prognosis of Parkinson’s disease. Research has established that glycolytic reprogramming serves as a critical regulator of inflammation initiation in pro-inflammatory macrophages. Furthermore, the modulation of glycolytic reprogramming has the potential to reverse the polarized state of these macrophages. Previous studies have shown that Levistilide A (LA), a phthalide component derived from Angelica sinensis, possesses a range of pharmacological effects, including anti-inflammatory, antioxidant, and neuroprotective properties. In our study, we have examined the impact of LA on inflammatory cytokines and glucose metabolism in microglia induced by lipopolysaccharide (LPS). Furthermore, we explored the effects of LA on the AMPK/mTOR pathway and assessed its neuroprotective potential both in vitro and in vivo. The findings revealed that LA notably diminished the expression of M1 pro-inflammatory factors induced by LPS in microglia, while leaving M2 anti-inflammatory factor expression unaltered. Additionally, it reduced ROS production and suppressed IκB-α phosphorylation levels as well as NF-κB p65 nuclear translocation. Notably, LA exhibited the ability to reverse microglial glucose metabolism reprogramming and modulate the phosphorylation levels of AMPK/mTOR. In vivo experiments further corroborated these findings, demonstrating that LA mitigated the death of TH-positive dopaminergic neurons and reduced microglia activation in the ventral SNpc brain region of the midbrain and the striatum. In summary, LA exhibited neuroprotective benefits by modulating the polarization state of microglia and altering glucose metabolism, highlighting its therapeutic potential. Full article

(This article belongs to the Section Natural Products Chemistry)

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26 pages, 8687 KiB

Open AccessArticle

Catalytic Supercritical Water Gasification of Canola Straw with Promoted and Supported Nickel-Based Catalysts

by Kapil Khandelwal and Ajay K. Dalai

Molecules 2024, 29(4), 911; https://doi.org/10.3390/molecules29040911 - 19 Feb 2024

Cited by 3 | Viewed by 1419

Abstract

Lignocellulosic biomass such as canola straw is produced as low-value residue from the canola processing industry. Its high cellulose and hemicellulose content makes it a suitable candidate for the production of hydrogen via supercritical water gasification. However, supercritical water gasification of lignocellulosic biomass [...] Read more.

Lignocellulosic biomass such as canola straw is produced as low-value residue from the canola processing industry. Its high cellulose and hemicellulose content makes it a suitable candidate for the production of hydrogen via supercritical water gasification. However, supercritical water gasification of lignocellulosic biomass such as canola straw suffers from low hydrogen yield, hydrogen selectivity, and conversion efficiencies. Cost-effective and sustainable catalysts with high catalytic activity for supercritical water gasification are increasingly becoming a focal point of interest. In this research study, novel wet-impregnated nickel-based catalysts supported on carbon-negative hydrochar obtained from hydrothermal liquefaction (HTL-HC) and hydrothermal carbonization (HTC-HC) of canola straw, along with other nickel-supported catalysts such as Ni/Al₂O₃, Ni/ZrO₂, Ni/CNT, and Ni/AC, were synthesized for gasification of canola straw on previously optimized reaction conditions of 500 °C, 60 min, 10 wt%, and 23–25 MPa. The order of hydrogen yield for the six supports was (10.5 mmol/g) Ni/ZrO₂ > (9.9 mmol/g) Ni/Al₂O₃ > (9.1 mmol/g) Ni/HTL-HC > (8.8 mmol/g) Ni/HTC-HC > (7.7 mmol/g) Ni/AC > (6.8 mmol/g) Ni/CNT, compared to 8.1 mmol/g for the non-catalytic run. The most suitable Ni/ZrO₂ catalyst was further modified using promotors such as K, Zn, and Ce, and the performance of the promoted Ni/ZrO₂ catalysts was evaluated. Ni-Ce/ZrO₂ showed the highest hydrogen yield of 12.9 mmol/g, followed by 12.0 mmol/g for Ni-Zn/ZrO₂ and 11.6 mmol/g for Ni-K/ZrO₂. The most suitable Ni-Ce/ZrO₂ catalysts also demonstrated high stability over their repeated use. The superior performance of the Ni-Ce/ZrO₂ was due to its high nickel dispersion, resilience to sintering, high thermal stability, and oxygen storage capabilities to minimize coke deposition. Full article

(This article belongs to the Special Issue Advances in Thermochemical Conversion of Solid Wastes)

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28 pages, 8386 KiB

Open AccessReview

Exploring Four Atraphaxis Species: Traditional Medicinal Uses, Phytochemistry, and Pharmacological Activities

by Alima Abilkassymova, Aknur Turgumbayeva, Lazzat Sarsenova, Kuanysh Tastambek, Nazym Altynbay, Gulnar Ziyaeva, Ravil Blatov, Gulmira Altynbayeva, Kuralay Bekesheva, Gulzhamal Abdieva, Perizat Ualieva, Zhanserik Shynykul and Assem Kalykova

Molecules 2024, 29(4), 910; https://doi.org/10.3390/molecules29040910 - 19 Feb 2024

Cited by 1 | Viewed by 1682

Abstract

Atraphaxis is a genus of flowering plants in the family Polygonaceae, with approximately 60 species. Species of Atraphaxis are much-branched woody plants, forming shrubs or shrubby tufts, primarily inhabiting arid zones across the temperate steppe and desert regions of Central Asia, America, and [...] Read more.

Atraphaxis is a genus of flowering plants in the family Polygonaceae, with approximately 60 species. Species of Atraphaxis are much-branched woody plants, forming shrubs or shrubby tufts, primarily inhabiting arid zones across the temperate steppe and desert regions of Central Asia, America, and Australia. Atraphaxis species have been used by diverse groups of people all over the world for the treatment of various diseases. However, their biologically active compounds with therapeutic properties have not been investigated well. Studying the biologically active components of Atraphaxis laetevirens, Atraphaxis frutescens, Atraphaxis spinosa L., and Atraphaxis pyrifolia is crucial for several reasons. Firstly, it can unveil the therapeutic potential of these plants, aiding in the development of novel medicines or natural remedies for various health conditions. Understanding their bioactive compounds enables scientists to explore their pharmacological properties, potentially leading to the discovery of new drugs or treatments. Additionally, investigating these components contributes to preserving traditional knowledge and validating the historical uses of these plants in ethnomedicine, thus supporting their conservation and sustainable utilization. These herbs have been used as an anti-inflammatory and hypertension remedies since the dawn of time. Moreover, they have been used to treat a variety of gastrointestinal disorders and problems related to skin in traditional Kazakh medicine. Hence, the genus Atraphaxis can be considered as a potential medicinal plant source that is very rich in biologically active compounds that may exhibit great pharmacological properties, such as antioxidant, antibacterial, antiulcer, hypoglycemic, wound healing, neuroprotective, antidiabetic, and so on. This study aims to provide a collection of publications on the species of Atraphaxis, along with a critical review of the literature data. This review will constitute support for further investigations on the pharmacological activity of these medicinal plant species. Full article

(This article belongs to the Special Issue Study on the Bioactive Compounds from Plant Extraction)

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12 pages, 2393 KiB

Open AccessArticle

Anti-Inflammatory Peroxidized Chlorahololide-Type Dimers Are Artifacts of Shizukaol-Type Dimers: From Phenomena Discovery and Confirmation to Potential Underlying Mechanism

by Xiu-Wen Yin, Ming Zhang, Lan Wu, Fu-Cai Ren, Fu-Rong Yang, Xiang-Dong Pu, Zhi-Jun Zhang and Chuan-Pu Shen

Molecules 2024, 29(4), 909; https://doi.org/10.3390/molecules29040909 - 19 Feb 2024

Cited by 1 | Viewed by 1000

Abstract

In our research on naturally occurring sesquiterpenes, eight shizukaol-type dimers, one chlorahololide-type dimer, and one sarcanolide-type dimer were isolated from the roots of Chloranthus fortunei. As the project was implemented, we accidentally discovered that shizukaol-type dimers can be converted into peroxidized chlorahololide-type dimers. [...] Read more.

In our research on naturally occurring sesquiterpenes, eight shizukaol-type dimers, one chlorahololide-type dimer, and one sarcanolide-type dimer were isolated from the roots of Chloranthus fortunei. As the project was implemented, we accidentally discovered that shizukaol-type dimers can be converted into peroxidized chlorahololide-type dimers. This potential change was discovered after simulations of the changes in corresponding shizukaols showed that three peroxide products were generated (1–3), indicating that peroxidation reactions occurred. HPLC-HR-MS analysis results obtained for the shizukaol derivatives further demonstrate that the reaction occurred, and the type of substituent of small organic ester moieties at positions C-15’ and C-13’ of unit B were not decisively related to the reaction. Quantum chemical calculations of the mode dimer further demonstrated this phenomenon. The highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy of the precursor and production revealed the advantageous yield of 4β-hydroperoxyl production. Additionally, the potential reaction mechanism was speculated and validated using the free energy in the reaction which successfully explained the feasibility of the reaction. Finally, the anti-inflammatory activity of the precursors and products was evaluated, and the products of peroxidation showed better anti-inflammatory activity. Full article

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18 pages, 4598 KiB

Open AccessArticle

Dendrobium Nobile Alcohol Extract Extends the Lifespan of Caenorhabditis elegans via hsf-1 and daf-16

by Linfeng Li, Zhen Liu, Huiling Hu, Renming Cai, Jingdou Bi, Qin Wang, Xiaogang Zhou, Huairong Luo, Chun Zhang and Runlan Wan

Molecules 2024, 29(4), 908; https://doi.org/10.3390/molecules29040908 - 19 Feb 2024

Cited by 1 | Viewed by 1792

Abstract

Dendrobium nobile is a traditional Chinese herb with anti-inflammatory, antioxidant, and neuroprotective properties. However, its antiaging effects are unclear. Herein, we studied the aging-related functions and the mechanism of action of the alcohol extract of Dendrobium nobile (DnAE) in the model organism Caenorhabditis [...] Read more.

Dendrobium nobile is a traditional Chinese herb with anti-inflammatory, antioxidant, and neuroprotective properties. However, its antiaging effects are unclear. Herein, we studied the aging-related functions and the mechanism of action of the alcohol extract of Dendrobium nobile (DnAE) in the model organism Caenorhabditis elegans. The results indicated that 1 mg/mL DnAE slowed lipofuscin accumulation, decreased the levels of reactive oxygen species, elevated superoxide dismutase activity, enhanced oxidative and heat stress resistance, extended the lifespan of nematodes, protected their dopamine neurons from 6-hydroxydopamine-induced neurodegeneration, and reduced Aβ-induced neurotoxicity. DnAE upregulated the mRNA expression of the transcription factors DAF-16 and HSF-1, promoted the nuclear localization of DAF-16, and enhanced the fluorescence intensity of HSP-16.2. However, it had no effect on the lifespan of DAF-16 mutants. Thus, DnAE can significantly extend lifespan, enhance heat stress tolerance, and delay age-related diseases through a DAF-16-dependent pathway. Full article

(This article belongs to the Special Issue Plants Extractions in Health Care)

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18 pages, 3952 KiB

Open AccessArticle

Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP)-Mediated Calcium Signaling Is Active in Memory CD4⁺ T Cells

by Anish Chakraborty, Ravindika Dissanayake and Katherine A. Wall

Molecules 2024, 29(4), 907; https://doi.org/10.3390/molecules29040907 - 19 Feb 2024

Viewed by 1422

Abstract

Nicotinic acid adenine dinucleotide phosphate (NAADP), identified as one of the most potent calcium-mobilizing second messengers, has been studied in different eukaryotic cell types, including lymphocytes. Although aspects of NAADP-mediated calcium release in lymphocytes are still under debate, the organelles pertaining to NAADP-mediated [...] Read more.

Nicotinic acid adenine dinucleotide phosphate (NAADP), identified as one of the most potent calcium-mobilizing second messengers, has been studied in different eukaryotic cell types, including lymphocytes. Although aspects of NAADP-mediated calcium release in lymphocytes are still under debate, the organelles pertaining to NAADP-mediated calcium release are often characterized as acidic and related to lysosomes. Although NAADP-mediated calcium release in different subsets of T cells, including naïve, effector and natural regulatory T cells, has been studied, it has not been widely studied in memory CD4⁺ T cells, which show a different calcium flux profile. Using a pharmacological approach, the effect of Ned-19, an NAADP pathway antagonist, on the involvement of NAADP in TCR activation in murine memory CD4⁺ T cells and their downstream effector functions, such as proliferation and cytokine production, was studied. According to this study, Ned-19 inhibited TCR-mediated calcium flux and its downstream effector functions in primary memory CD4⁺ T cells. The study also revealed that both extracellular and intracellular calcium stores, including endoplasmic reticulum and lysosome-like acidic calcium stores, contribute to the TCR-mediated calcium flux in memory CD4⁺ T cells. NAADP-AM, a cell permeable analogue of NAADP, was shown to release calcium in memory CD4⁺ T cells and calcium flux was inhibited by Ned-19. Full article

(This article belongs to the Section Chemical Biology)

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15 pages, 5139 KiB

Open AccessArticle

Salvianolic Acid B Significantly Suppresses the Migration of Melanoma Cells via Direct Interaction with β-Actin

by Ying Zhang, Wenjuan Zhai, Minqi Fan, Jinjun Wu and Caiyan Wang

Molecules 2024, 29(4), 906; https://doi.org/10.3390/molecules29040906 - 19 Feb 2024

Cited by 1 | Viewed by 1280

Abstract

Melanoma is the most aggressive and difficult to treat of all skin cancers. Despite advances in the treatment of melanoma, the prognosis for melanoma patients remains poor, and the recurrence rate remains high. There is substantial evidence that Chinese herbals effectively prevent and [...] Read more.

Melanoma is the most aggressive and difficult to treat of all skin cancers. Despite advances in the treatment of melanoma, the prognosis for melanoma patients remains poor, and the recurrence rate remains high. There is substantial evidence that Chinese herbals effectively prevent and treat melanoma. The bioactive ingredient Salvianolic acid B (SAB) found in Salvia miltiorrhiza, a well-known Chinese herbal with various biological functions, exhibits inhibitory activity against various cancers. A375 and mouse B16 cell lines were used to evaluate the main targets and mechanisms of SAB in inhibiting melanoma migration. Online bioinformatics analysis, Western blotting, immunofluorescence, molecular fishing, dot blot, and molecular docking assays were carried out to clarify the potential molecular mechanism. We found that SAB prevents the migration and invasion of melanoma cells by inhibiting the epithelial–mesenchymal transition (EMT) process of melanoma cells. As well as interacting directly with the N-terminal domain of β-actin, SAB enhanced its compactness and stability, thereby inhibiting the migration of cells. Taken together, SAB could significantly suppress the migration of melanoma cells via direct binding with β-actin, suggesting that SAB could be a helpful supplement that may enhance chemotherapeutic outcomes and benefit melanoma patients. Full article

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2 pages, 2302 KiB

Open AccessCorrection

Correction: Eid et al. Interference with TGFβ1-Mediated Inflammation and Fibrosis Underlies Reno-Protective Effects of the CB1 Receptor Neutral Antagonists AM6545 and AM4113 in a Rat Model of Metabolic Syndrome. Molecules 2021, 26, 866

by Basma G. Eid, Thikryat Neamatallah, Abeer Hanafy, Hany M. El-Bassossy, Lenah Binmahfouz, Hibah M. Aldawsari, Atif Hasan, Gamal Abd El-Aziz, Kiran Vemuri and Alexandros Makriyannis

Molecules 2024, 29(4), 902; https://doi.org/10.3390/molecules29040902 - 19 Feb 2024

Viewed by 874

Abstract

The authors wish to make the following changes to the paper [...] Full article

(This article belongs to the Special Issue Cannabinergic Ligands: Chemistry, Pharmacology and Therapeutic Potential)

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15 pages, 13056 KiB

Open AccessArticle

Activation Mechanism of Ammonium Fluoride in Facile Synthesis of Hydrated Silica Derived from Ferronickel Slag-Leaching Residue

by Xuqin Duan, Yu Zhang, Dong Li, Tong Liu and Yanjun Jiang

Molecules 2024, 29(4), 905; https://doi.org/10.3390/molecules29040905 - 18 Feb 2024

Viewed by 1151

Abstract

A novel process for the synthesis of hydrated silica derived from ferronickel slag (FNS)-leaching residue was proposed in this study. The products of the purification of hydrated silica with 99.68% grade and 95.11% recovery can be obtained through ammonium fluoride (NH₄F) [...] Read more.

A novel process for the synthesis of hydrated silica derived from ferronickel slag (FNS)-leaching residue was proposed in this study. The products of the purification of hydrated silica with 99.68% grade and 95.11% recovery can be obtained through ammonium fluoride (NH₄F) roasting, followed by the process of water leaching, ammonia precipitating, and acid cleaning under the optimized conditions. The effects of NH₄F mass ratio, roasting temperature, and roasting time on the water-leaching efficiency were investigated in detail. The thermodynamic and X-ray diffraction analyses indicated that the amorphous silica in FNS-leaching residue was converted to water-soluble fluoride salts ((NH₄)₂SiF₆) during the roasting process, which are also supported by the scanning electron microscopy and thermogravimetry analyses. The Si–O bonds in amorphous silica could be effectively broken through the ammonium fluoride activation during a low-temperature roasting process. This work provides a meaningful reference for further studies on the facile synthesis of hydrated silica with similar mineral compositions. Full article

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12 pages, 247 KiB

Open AccessArticle

The Influence of Arabinoxylans on the Properties of Wheat Bread Baked Using the Postponed Baking Method

by Angelika Bieniek and Krzysztof Buksa

Molecules 2024, 29(4), 904; https://doi.org/10.3390/molecules29040904 - 18 Feb 2024

Cited by 3 | Viewed by 1162

Abstract

Bread is a basic element of the human diet. To counteract the process of its going stale, semi-finished bakery products are subjected to cooling or freezing. This process is called postponed baking. The aim of this work was to investigate the effect of [...] Read more.

Bread is a basic element of the human diet. To counteract the process of its going stale, semi-finished bakery products are subjected to cooling or freezing. This process is called postponed baking. The aim of this work was to investigate the effect of the molar mass of rye arabinoxylans (AXs) on the properties of wheat breads baked using the postponed baking method. Breads were produced using the postponed baking method from wheat flour without and with 1 or 2% share of rye AXs clearly differing in molar masses—non-modified or modified AXs by means of partial hydrolysis and cross-linking. The molar mass of non-modified AXs was 413,800 g/mol, that of AXs after partial hydrolysis was 192,320 g/mol, and that of AXs after cross-linking was 535,630 g/mol. The findings showed that the addition of all AX preparations significantly increased the water absorption of the baking mixture, and the increase was proportional to the molar mass of AXs used as well as the share of AX preparation. Moreover, for the first time, it was shown that 1% share of partly hydrolyzed AXs, of a low molar mass, in the baking mixture had the highest effect on increasing the volume of bread and reducing the hardness of the bread crumb of bread baked using postponed baking method. It was also shown that the AXs had a low and inconclusive effect on the baking loss and moisture content of the bread crumb. Full article

(This article belongs to the Special Issue Physicochemical Study of Foods, 2nd Edition)

21 pages, 2119 KiB

Open AccessReview

Machine Learning Empowering Drug Discovery: Applications, Opportunities and Challenges

by Xin Qi, Yuanchun Zhao, Zhuang Qi, Siyu Hou and Jiajia Chen

Molecules 2024, 29(4), 903; https://doi.org/10.3390/molecules29040903 - 18 Feb 2024

Cited by 8 | Viewed by 5156

Abstract

Drug discovery plays a critical role in advancing human health by developing new medications and treatments to combat diseases. How to accelerate the pace and reduce the costs of new drug discovery has long been a key concern for the pharmaceutical industry. Fortunately, [...] Read more.

Drug discovery plays a critical role in advancing human health by developing new medications and treatments to combat diseases. How to accelerate the pace and reduce the costs of new drug discovery has long been a key concern for the pharmaceutical industry. Fortunately, by leveraging advanced algorithms, computational power and biological big data, artificial intelligence (AI) technology, especially machine learning (ML), holds the promise of making the hunt for new drugs more efficient. Recently, the Transformer-based models that have achieved revolutionary breakthroughs in natural language processing have sparked a new era of their applications in drug discovery. Herein, we introduce the latest applications of ML in drug discovery, highlight the potential of advanced Transformer-based ML models, and discuss the future prospects and challenges in the field. Full article

(This article belongs to the Special Issue Computational Approaches in Drug Discovery and Design)

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16 pages, 712 KiB

Open AccessArticle

Bioaccessibility of Rosmarinic Acid and Basil (Ocimum basilicum L.) Co-Compounds in a Simulated Digestion Model—The Influence of the Endogenous Plant Matrix, Dose of Administration and Physicochemical and Biochemical Digestion Environment

by Łukasz Sęczyk and Barbara Kołodziej

Molecules 2024, 29(4), 901; https://doi.org/10.3390/molecules29040901 - 18 Feb 2024

Viewed by 1098

Abstract

The objective of this study is to determine the effect of endogenous plant matrix components, dose and digestion-related factors on the bioaccessibility of rosmarinic acid and basil co-compounds in in vitro digestion conditions. Different forms of administration, i.e., basil raw plant material, dry [...] Read more.

The objective of this study is to determine the effect of endogenous plant matrix components, dose and digestion-related factors on the bioaccessibility of rosmarinic acid and basil co-compounds in in vitro digestion conditions. Different forms of administration, i.e., basil raw plant material, dry extract, and isolated rosmarinic acid at various doses, were applied for the digestion experiment. To evaluate the contribution of biochemical and physicochemical digestion factors, samples were subjected to a full digestion process or treated only with a digestion fluid electrolyte composition without using biochemical components (i.e., digestion enzymes and bile salts), and bioaccessibility was monitored at the gastric and intestinal steps of digestion. The results showed that the components of the endogenous raw plant matrix significantly limited the bioaccessibility of rosmarinic acid and basil co-compounds, especially at the gastric stage of digestion. Physicochemical digestion factors were mainly responsible for the bioaccessibility of basil phytochemicals. Higher doses allowed maintenance of bioaccessibility at a relatively similar level, whereas the most negative changes in bioaccessibility were induced by the lowest doses. In conclusion, the determination of the bioaccessibility of bioactive phytochemicals from basil and factors influencing bioaccessibility may help in better prediction of the pro-health potential of this plant. Full article

(This article belongs to the Special Issue Bio-Accessibility/Availability of Bioactive Compounds from Natural Food Sources)

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17 pages, 6634 KiB

Open AccessArticle

Purification, Characterization, cDNA Cloning, and Bioinformatic Analysis of Zinc-Binding Protein from Magallana hongkongensis

by Citing Chen, Wan Li, Jialong Gao, Wenhong Cao, Xiaoming Qin, Huina Zheng, Haisheng Lin and Zhongqin Chen

Molecules 2024, 29(4), 900; https://doi.org/10.3390/molecules29040900 - 18 Feb 2024

Viewed by 1171

Abstract

Oysters contain significant amounts of the zinc element, which may also be found in their proteins. In this study, a novel zinc-binding protein was purified from the mantle of the oyster Magallana hongkongensis using two kinds of gel filtration chromatograms. Sodium dodecyl sulfate–polyacrylamide [...] Read more.

Oysters contain significant amounts of the zinc element, which may also be found in their proteins. In this study, a novel zinc-binding protein was purified from the mantle of the oyster Magallana hongkongensis using two kinds of gel filtration chromatograms. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) showed that its molecular weight was approximately 36 kDa. The protein identified by the Q-Exactive mass spectrometer shared the highest sequence identity with carbonic anhydrase derived from Crassostrea gigas concerning amino acid sequence similarity. Based on homologous cloning and RACE PCR, the full-length cDNA of carbonic anhydrase from Magallana hongkongensis (designated as MhCA) was cloned and sequenced. The cDNA of MhCA encodes a 315-amino-acid protein with 89.74% homology to carbonic anhydrase derived from Crassostrea gigas. Molecular docking revealed that the two zinc ions primarily form coordination bonds with histidine residues in the MhCA protein. These results strongly suggest that MhCA is a novel zinc-binding protein in Magallana hongkongensis. Full article

(This article belongs to the Special Issue Structural and Functional Properties of Food Proteins)

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16 pages, 3998 KiB

Open AccessArticle

Efficient Capture of Cannabis Terpenes in Olive Oil during Microwave-Assisted Cannabinoid Decarboxylation

by Luisa Boffa, Arianna Binello and Giancarlo Cravotto

Molecules 2024, 29(4), 899; https://doi.org/10.3390/molecules29040899 - 18 Feb 2024

Cited by 1 | Viewed by 2520

Abstract

The development of selective extraction protocols for Cannabis-inflorescence constituents is still a significant challenge. The characteristic Cannabis fragrance can be mainly ascribed to monoterpenes, sesquiterpenes and oxygenated terpenoids. This work investigates the entrapment of Cannabis terpenes in olive oil from inflorescences via [...] Read more.

The development of selective extraction protocols for Cannabis-inflorescence constituents is still a significant challenge. The characteristic Cannabis fragrance can be mainly ascribed to monoterpenes, sesquiterpenes and oxygenated terpenoids. This work investigates the entrapment of Cannabis terpenes in olive oil from inflorescences via stripping under mild vacuum during the rapid microwave-assisted decarboxylation of cannabinoids (MW, 120 °C, 30 min) and after subsequent extraction of cannabinoids (60 and 100 °C). The profiles of the volatiles collected in the oil samples before and after the extraction step were evaluated using static headspace solid-phase microextraction (HS-SPME), followed by gas chromatography coupled to mass spectrometry (GC-MS). Between the three fractions obtained, the first shows the highest volatile content (~37,400 mg/kg oil), with α-pinene, β-pinene, β-myrcene, limonene and trans-β-caryophyllene as the main components. The MW-assisted extraction at 60 and 100 °C of inflorescences using the collected oil fractions allowed an increase of 70% and 86% of total terpene content, respectively. Considering the initial terpene amount of 91,324.7 ± 2774.4 mg/kg dry inflorescences, the percentage of recovery after decarboxylation was close to 58% (mainly monoterpenes), while it reached nearly 100% (including sesquiterpenes) after extraction. The selective and efficient extraction of volatile compounds, while avoiding direct contact between the matrix and extraction solvents, paves the way for specific applications in various aromatic plants. In this context, aromatized extracts can be employed to create innovative Cannabis-based products within the hemp processing industry, as well as in perfumery, cosmetics, dietary supplements, food, and the pharmaceutical industry. Full article

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15 pages, 1978 KiB

Open AccessArticle

Ionic Liquid Modified Polymer Gel for Arsenic Speciation

by Ivanka Dakova and Irina Karadjova

Molecules 2024, 29(4), 898; https://doi.org/10.3390/molecules29040898 - 18 Feb 2024

Cited by 1 | Viewed by 1031

Abstract

A new ionic liquid modified polymer gel containing methylimidazolium groups (poly(MIA)) is proposed as a sorbent for the separation and enrichment of trace inorganic and organic arsenic species in surface waters. The poly(MIA) was synthesized by chemical modification of polymeric precursor using post-polymerization [...] Read more.

A new ionic liquid modified polymer gel containing methylimidazolium groups (poly(MIA)) is proposed as a sorbent for the separation and enrichment of trace inorganic and organic arsenic species in surface waters. The poly(MIA) was synthesized by chemical modification of polymeric precursor using post-polymerization modification of poly(glycidyl methacrylate-co-trimethylolpropane trimethacrylate). The composition, structure, morphology, and surface properties of the prepared particles were characterized using elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption–desorption measurements. Optimization experiments showed that at pH 8, monomethylarsonic acid (MMAs), dimethylarsinic acid (DMAs), and As(V) were completely retained on the poly(MIA), while the sorption of As(III) was insignificant. The desorption experiments revealed that due to the weaker binding of organic arsenic species, selective elution with 1 mol/L acetic acid for MMAs + DMAs, followed by elution with 2 mol/L hydrochloric acid for As(V), ensured their quantitative separation. The adsorption kinetic and mechanism were defined. The analytical procedure for As(III), As(V), MMAs, and DMAs determination in surface waters was developed and validated through the analysis of certified reference material. Full article

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14 pages, 6214 KiB

Open AccessArticle

Investigation on Gold Dissolution Performance and Mechanism in Imidazolium Cyanate Ionic Liquids

by Na Zhang, Yuxin Zhang, Zhengyu Liu, Ziyuan Liu, Chunbao Sun, N. Emre Altun and Jue Kou

Molecules 2024, 29(4), 897; https://doi.org/10.3390/molecules29040897 - 18 Feb 2024

Viewed by 1331

Abstract

To explore green gold leaching reagents, a series of imidazolium cyanate ionic liquids (ILs), 1-ethyl-3-methyl-imidazolium cyanate ([C₂MIM][OCN]), 1-propyl-3-methyl-imidazolium cyanate ([C₃MIM][OCN]) and 1-butyl-3-methyl-imidazolcyanate ([C₄MIM][OCN]) were synthesized and characterized by Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR) [...] Read more.

To explore green gold leaching reagents, a series of imidazolium cyanate ionic liquids (ILs), 1-ethyl-3-methyl-imidazolium cyanate ([C₂MIM][OCN]), 1-propyl-3-methyl-imidazolium cyanate ([C₃MIM][OCN]) and 1-butyl-3-methyl-imidazolcyanate ([C₄MIM][OCN]) were synthesized and characterized by Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR) and thermogravimetric (TG) analysis. In this research, the imidazolium cyanates were utilized as a solute, which not only decreased the usage of ILs but also increased their gold dissolution capability. The gold dissolution performances of three imidazolium cyanates were characterized by dynamic leaching test and Scanning Electron Microscopy (SEM). The results show that the all three imidazolium cyanates had a gold dissolution ability, and the shorter the carbon chain on the imidazole ring in imidazolium cyanate, the faster the gold dissolution rate. The gold dissolution performance of [C₂MIM][OCN] was the best, and the weight loss of gold leaf was 2.9 mg/cm² at 40 °C after 120 h dissolution in [C₂MIM][OCN] mixed with 10 wt. % water. Besides this, the gold dissolution rate increased with the increase in the concentration of imidazolium cyanates as well as the reaction temperature. The gold dissolution performances of imidazolium cyanates in different solvents including water, acetonitrile, dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) were also investigated, and the weaker the polarity of the solvent, the more conducive it was to the gold dissolution reaction. The mechanism of gold dissolution by imidazolium cyanates was investigated through NMR spectroscopy and Electrospray Ionization Mass Spectrometry (ESI-MS). It was inferred that during the process of gold dissolution, Au was oxidized to Au⁺ and the imidazolium cations were deprotonated to form N-heterocyclic carbenes, which coordinated with gold to form gold complexes and achieve gold dissolution. Full article

(This article belongs to the Section Electrochemistry)

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15 pages, 1859 KiB

Open AccessReview

Therapeutic Potential of Pectin and Its Derivatives in Chronic Diseases

by Anathi Dambuza, Pamela Rungqu, Adebola Omowunmi Oyedeji, Gugulethu Miya, Ayodeji Oluwabunmi Oriola, Yiseyon Sunday Hosu and Opeoluwa Oyehan Oyedeji

Molecules 2024, 29(4), 896; https://doi.org/10.3390/molecules29040896 - 18 Feb 2024

Cited by 3 | Viewed by 2555

Abstract

Non-communicable diseases (NCDs) are described as a collection of chronic diseases that do not typically develop from an acute infection, have long-term health effects, and frequently require ongoing care and therapy. These diseases include heart disease, stroke, cancer, chronic lung disease, neurological diseases, [...] Read more.

Non-communicable diseases (NCDs) are described as a collection of chronic diseases that do not typically develop from an acute infection, have long-term health effects, and frequently require ongoing care and therapy. These diseases include heart disease, stroke, cancer, chronic lung disease, neurological diseases, osteoporosis, mental health disorders, etc. Known synthetic drugs for the treatment or prevention of NCDs become increasingly dangerous over time and pose high risks due to side effects such as hallucination, heart attack, liver failure, etc. As a result, scientists have had to look for other alternatives that are natural products and that are known to be less detrimental and contain useful bioactive compounds. The increasing understanding of the biological and pharmacological significance of carbohydrates has helped to raise awareness of their importance in living systems and medicine, given they play numerous biological roles. For example, pectin has been identified as a class of secondary metabolites found in medicinal plants that may play a significant role in the treatment and management of a variety of NCDs. Pectin is mainly made of homogalacturonan, which is a linear polymer composed primarily of D-galacturonic acid units (at least 65%) linked in a chain by α-(1,4)-glycosidic linkages. There are also modified pectins or derivatives that improve pectin’s bioavailability. Pectin is found in the cell walls of higher plants (pteridophytes, angiosperms, and gymnosperms), particularly in the middle lamella of the plant material. Citrus pectin is used in various industries. This article compiles information that has been available for years about the therapeutic importance of pectin in chronic diseases, different modes of pectin extraction, the chemistry of pectin, and the potency of pectin and its derivatives. Full article

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12 pages, 3119 KiB

Open AccessArticle

Inhibitors of Transthyretin Amyloidosis: How to Rank Drug Candidates Using X-ray Crystallography Data

by José P. Leite, Diogo Costa-Rodrigues and Luís Gales

Molecules 2024, 29(4), 895; https://doi.org/10.3390/molecules29040895 - 18 Feb 2024

Viewed by 1398

Abstract

Amyloidosis is a group of protein misfolding diseases, which include spongiform encephalopathies, Alzheimer’s disease and transthyretin (TTR) amyloidosis; all of them are characterized by extracellular deposits of an insoluble fibrillar protein. TTR amyloidosis is a highly debilitating and life-threatening disease. Patients carry less [...] Read more.

Amyloidosis is a group of protein misfolding diseases, which include spongiform encephalopathies, Alzheimer’s disease and transthyretin (TTR) amyloidosis; all of them are characterized by extracellular deposits of an insoluble fibrillar protein. TTR amyloidosis is a highly debilitating and life-threatening disease. Patients carry less stable TTR homotetramers that are prone to dissociation into non-native monomers, which in turn rapidly self-assemble into oligomers and, ultimately, amyloid fibrils. Liver transplantation to induce the production of wild-type TTR was the only therapeutic strategy until recently. A promising approach to ameliorate transthyretin (TTR) amyloidosis is based on the so-called TTR kinetic stabilizers. More than 1000 TTR stabilizers have already been tested by many research groups, but the diversity of experimental techniques and conditions used hampers an objective prioritization of the compounds. One of the most reliable and unambiguous techniques applied to determine the structures of the TTR/drug complexes is X-ray diffraction. Most of the potential inhibitors bind in the TTR channel and the crystal structures reveal the atomic details of the interaction between the protein and the compound. Here we suggest that the stabilization effect is associated with a compaction of the quaternary structure of the protein and propose a scoring function to rank drugs based on X-ray crystallography data. Full article

(This article belongs to the Section Molecular Structure)

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15 pages, 1463 KiB

Open AccessCommunication

Microwave-Mediated, Catalyst-Free Synthesis of 1,2,4-Triazolo[1,5-a]pyridines from Enaminonitriles

by Kwanghee Lee, Young-Ah Kim, Chanhyun Jung, Jaeuk Sim, Shanmugam Rajasekar, Jae-Hwan Kwak, Mayavan Viji and Jae-Kyung Jung

Molecules 2024, 29(4), 894; https://doi.org/10.3390/molecules29040894 - 18 Feb 2024

Cited by 1 | Viewed by 1206

Abstract

A catalyst-free, additive-free, and eco-friendly method for synthesizing 1,2,4-triazolo[1,5-a]pyridines under microwave conditions has been established. This tandem reaction involves the use of enaminonitriles and benzohydrazides, a transamidation mechanism followed by nucleophilic addition with nitrile, and subsequent condensation to yield the target [...] Read more.

A catalyst-free, additive-free, and eco-friendly method for synthesizing 1,2,4-triazolo[1,5-a]pyridines under microwave conditions has been established. This tandem reaction involves the use of enaminonitriles and benzohydrazides, a transamidation mechanism followed by nucleophilic addition with nitrile, and subsequent condensation to yield the target compound in a short reaction time. The methodology demonstrates a broad substrate scope and good functional group tolerance, resulting in the formation of products in good-to-excellent yields. Furthermore, the scale-up reaction and late-stage functionalization of triazolo pyridine further demonstrate its synthetic utility. A plausible reaction pathway, based on our findings, has been proposed. Full article

(This article belongs to the Section Organic Chemistry)

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1 pages, 134 KiB

Open AccessCorrection

Correction: Ghani et al. Multi-Dimensional Antioxidant Screening of Selected Australian Native Plants and Putative Annotation of Active Compounds. Molecules 2023, 28, 3106

by Md. Ahsan Ghani, Celia Barril, Danny R. Bedgood, Jr., Geoffrey E. Burrows, Danielle Ryan and Paul D. Prenzler

Molecules 2024, 29(4), 893; https://doi.org/10.3390/molecules29040893 - 18 Feb 2024

Viewed by 694

Abstract

In the original publication [...] Full article

(This article belongs to the Section Natural Products Chemistry)

3 pages, 194 KiB

Open AccessComment

Comment on Naef, R.; Acree, W.E., Jr. Calculation of the Three Partition Coefficients logPow, logKoa and logKaw of Organic Molecules at Standard Conditions at Once by Means of a Generally Applicable Group Additivity Method. Preprints 2023, 2023120275

by Robert J. Meier

Molecules 2024, 29(4), 892; https://doi.org/10.3390/molecules29040892 - 18 Feb 2024

Viewed by 675

Abstract

Next to the paper referred to in the title [...] Full article

31 pages, 2895 KiB

Open AccessReview

An Umbrella Insight into the Phytochemistry Features and Biological Activities of Corn Silk: A Narrative Review

by Yumei Wang, Jialin Mao, Meng Zhang, Lei Liu, Yu Zhu, Meiling Gu, Jinling Zhang, Hongzhou Bu, Yu Sun, Jia Sun, Yukun Ma, Lina Guo, Yan Zheng and Qi Liu

Molecules 2024, 29(4), 891; https://doi.org/10.3390/molecules29040891 - 18 Feb 2024

Cited by 1 | Viewed by 2672

Abstract

Corn silk (Zea mays L.) is the stigma of an annual gramineous plant named corn, which is distributed in many regions worldwide and has a long history of medicinal use. In recent years, with the sustainable development of traditional Chinese medicine, [...] Read more.

Corn silk (Zea mays L.) is the stigma of an annual gramineous plant named corn, which is distributed in many regions worldwide and has a long history of medicinal use. In recent years, with the sustainable development of traditional Chinese medicine, studies of corn silk based on modern technologies, such as GC–MS, LC–MS, and other analytical means, have offered more comprehensive analyses. Phytochemistry studies have shown that the main bioactive components in corn silk include flavonoids, polyphenols, phenolic acids, fatty acids, and terpenoids. Pharmacological studies have shown that corn silk extract has various pharmacological effects, such as reducing blood lipids, lowering blood pressure, regulating blood sugar levels, anti-inflammatory effects, and anti-oxidation effects. In this paper, the related research on corn silk from the past few years is summarized to provide a theoretical reference for the further development and utilization of corn silk. Full article

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16 pages, 2218 KiB

Open AccessArticle

Reaction of Partially Methylated Polygalacturonic Acid with Iron(III) Chloride and Characterization of a New Mixed Chloride–Polygalacturonate Complex

by László Kótai, Károly Lázár, László Ferenc Kiss and Klára Szentmihályi

Molecules 2024, 29(4), 890; https://doi.org/10.3390/molecules29040890 - 17 Feb 2024

Viewed by 1211

Abstract

We have described a new route for the preparation of partially methylated polygalacturonic acid containing hydrolyzed (acidic) and unhydrolyzed (methyl esterified) carboxylate groups in a ratio of 1:1 (PGA, compound 1), and one of its basic Fe^III—salts (compound 2) [...] Read more.

We have described a new route for the preparation of partially methylated polygalacturonic acid containing hydrolyzed (acidic) and unhydrolyzed (methyl esterified) carboxylate groups in a ratio of 1:1 (PGA, compound 1), and one of its basic Fe^III—salts (compound 2) with a ~1:2 Fe^III:GA stoichiometry (GA means galacturonic acid and methylated galacturonic acid units). The partially hydrolyzed pectin was transformed into compound 1 with the use of double ion exchange with a strongly acidic macroreticular sulfonated styrene–divinylbenzene copolymer as a hydrogen ion source. The reaction of compound 1 with FeCl₃ resulted in compound 2. Compound 2 has a polymeric nature and contains binuclear Fe^III(µ-O)(µ-OH)Fe^III core units with two kinds of distorted octahedral iron geometries. The salt-forming acidic and methylated GA units of compound 1 are coordinated to Fe^III centers in asymmetric bidentate-chelating and -bridging (via C=O group and glycosidic oxygen) modes, respectively. Two kinds of outer-sphere chloride anions were also detected by XPS in various chemical environments fixed by different sets of hydrogen bonds. We also observed a partial reduction of Fe^III into Fe^II due to the ring-opening of the chain-end GA units of compound 1. This reaction provides a new route to determine the number of chain-ends in compound 2, and with the use of the number of GA units calculated from charge neutrality, the average length of these chains and the average molecular weight were also determined. The average molecular weight of the partially methylated polygalacturonic acid used in the industrial-scale production of commercial anti-anemic iron–polygalacturonate agents was ~50,000 g/mol. Compound 2 was also characterized by IR, Mössbauer, and X-ray photoelectron spectroscopy, and magnetic susceptibility measurements. These results on the structure and average molecular weight of basic iron(III) polygalacturonate provide a tool to design Fe-PGA complexes with tuned iron-releasing properties. Full article

(This article belongs to the Special Issue Synthesis, Structure, Molecular Modeling, and Bioactivity of Metal Complexes)

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