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Molecules, Volume 25, Issue 13 (July-1 2020) – 150 articles

Cover Story (view full-size image): Human health, crop protection and environmental protection need to coexist to embrace the principles of the green economy. Therefore, the development of non-toxic, environmentally friendly insecticides and fungicides would be extremely beneficial, especially for less-developed countries. A quite recent approach identified trehalase inhibitors as excellent candidates for new “green and safe insecticides”. Indeed, the trehalase enzyme hydrolyses trehalose, a sugar essential to the life functions of many organisms, particularly fungi and insects, but not vertebrates. In this review, trehalase inhibitors based on sugars and sugar mimics showing good inhibitory properties towards insect trehalases are analyzed, with the aim of providing a useful tool to develop more efficient green and human-safe insecticides. View this paper.
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Article
Juglone Suppresses LPS-induced Inflammatory Responses and NLRP3 Activation in Macrophages
Molecules 2020, 25(13), 3104; https://doi.org/10.3390/molecules25133104 - 07 Jul 2020
Cited by 3 | Viewed by 1103
Abstract
The NLRP3 (NACHT, LRR and PYD domains-containing protein 3) inflammasome has been implicated in a variety of diseases, including atherosclerosis, neurodegenerative diseases, and infectious diseases. Thus, inhibitors of NLRP3 inflammasome have emerged as promising approaches to treat inflammation-related diseases. The aim of this [...] Read more.
The NLRP3 (NACHT, LRR and PYD domains-containing protein 3) inflammasome has been implicated in a variety of diseases, including atherosclerosis, neurodegenerative diseases, and infectious diseases. Thus, inhibitors of NLRP3 inflammasome have emerged as promising approaches to treat inflammation-related diseases. The aim of this study was to explore the effects of juglone (5-hydroxyl-1,4-naphthoquinone) on NLRP3 inflammasome activation. The inhibitory effects of juglone on nitric oxide (NO) production were assessed in lipopolysaccharide (LPS)-stimulated J774.1 cells by Griess assay, while its effects on reactive oxygen species (ROS) and NLRP3 ATPase activity were assessed. The expression levels of NLRP3, caspase-1, and pro-inflammatory cytokines (IL-1β, IL-18) and cytotoxicity of juglone in J774.1 cells were also determined. Juglone was non-toxic in J774.1 cells when used at 10 μM (p < 0.01). Juglone treatment inhibited the production of ROS and NO. The levels of NLRP3 and cleaved caspase-1, as well as the secretion of IL-1β and IL-18, were decreased by treatment with juglone in a concentration-dependent manner. Juglone also inhibited the ATPase activities of NLRP3 in LPS/ATP-stimulated J774.1 macrophages. Our results suggested that juglone could inhibit inflammatory cytokine production and NLRP3 inflammasome activation in macrophages, and should be considered as a therapeutic strategy for inflammation-related diseases. Full article
(This article belongs to the Special Issue Biological and Pharmacological Activity of Plant Natural Compounds)
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Article
Design, Synthesis and Biological Evaluation of Novel Anthraniloyl-AMP Mimics as PQS Biosynthesis Inhibitors Against Pseudomonas aeruginosa Resistance
Molecules 2020, 25(13), 3103; https://doi.org/10.3390/molecules25133103 - 07 Jul 2020
Cited by 2 | Viewed by 1139
Abstract
The Pseudomonas quinolone system (PQS) is one of the three major interconnected quorum sensing signaling systems in Pseudomonas aeruginosa. The virulence factors PQS and HHQ activate the transcription regulator PqsR (MvfR), which controls several activities in bacteria, including biofilm formation and upregulation [...] Read more.
The Pseudomonas quinolone system (PQS) is one of the three major interconnected quorum sensing signaling systems in Pseudomonas aeruginosa. The virulence factors PQS and HHQ activate the transcription regulator PqsR (MvfR), which controls several activities in bacteria, including biofilm formation and upregulation of PQS biosynthesis. The enzyme anthraniloyl-CoA synthetase (PqsA) catalyzes the first and critical step in the biosynthesis of quinolones; therefore, it is an attractive target for the development of anti-virulence therapeutics against Pseudomonas resistance. Herein, we report the design and synthesis of novel triazole nucleoside-based anthraniloyl- adenosine monophosphate (AMP) mimics. These analogues had a major impact on the morphology of bacterial biofilms and caused significant reduction in bacterial aggregation and population density. However, the compounds showed only limited inhibition of PQS and did not exhibit any effect on pyocyanin production. Full article
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Article
Granzyme B PET Imaging of the Innate Immune Response
Molecules 2020, 25(13), 3102; https://doi.org/10.3390/molecules25133102 - 07 Jul 2020
Viewed by 823
Abstract
The human immune system is a complex system which protects against invaders and maintains tissue homeostasis. It is broadly divided into the innate and adaptive branches. Granzyme B is serine protease that plays an important role in both and can serve as a [...] Read more.
The human immune system is a complex system which protects against invaders and maintains tissue homeostasis. It is broadly divided into the innate and adaptive branches. Granzyme B is serine protease that plays an important role in both and can serve as a biomarker for cellular activation. Because of this, a granzyme B PET agent (GZP) has recently been developed and has been shown to be able to monitor response to immunotherapy. Here, we evaluated the utility of granzyme B PET imaging to assess the innate immune response. We subcutaneously administered LPS to mice to induce inflammation and performed granzyme B PET imaging after 24 and 120 h. We dissected out tissue in the region of injection and performed granzyme B immunofluorescence (IF) to confirm specificity of the GZP radiotracer. Granzyme B PET imaging demonstrated increased uptake in the region of LPS injection after 24 h, which normalized at 120 h. Granzyme B immunofluorescence showed specific staining in tissue from the 24 h time point compared to the PBS-injected control. These findings support the use of granzyme B PET for imaging innate immunity. In certain clinical contexts, the use of GZP PET imaging may be superior to currently available agents, and we therefore suggest further preclinical studies with the ultimate goal of translation to clinical use. Full article
(This article belongs to the Special Issue Novel Molecular Imaging for Therapeutic Development)
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Article
The Inhibitory Activity of Anthraquinones against Pathogenic Protozoa, Bacteria, and Fungi and the Relationship to Structure
Molecules 2020, 25(13), 3101; https://doi.org/10.3390/molecules25133101 - 07 Jul 2020
Cited by 2 | Viewed by 1115
Abstract
Plant-derived anthraquinones were evaluated in cell assays for their inhibitory activities against the parasitic protozoa Trichomonas vaginalis human strain G3 that causes the sexually transmitted disease trichomoniasis in women, Tritrichomonas foetus bovine strain D1 that causes sexually transmitted diseases in farm animals (bulls, [...] Read more.
Plant-derived anthraquinones were evaluated in cell assays for their inhibitory activities against the parasitic protozoa Trichomonas vaginalis human strain G3 that causes the sexually transmitted disease trichomoniasis in women, Tritrichomonas foetus bovine strain D1 that causes sexually transmitted diseases in farm animals (bulls, cows, and pigs), Tritrichomonas foetus-like strain C1 that causes diarrhea in domestic animals (cats and dogs), and bacteria and fungi. The anthraquinones assessed for their inhibitory activity were anthraquinone, aloe-emodin (1,8-dihydroxy-3-hydroxymethylanthraquinone), anthrarufin (1,5-dihydroxyanthraquinone), chrysazin (1,8-dihydroxyanthraquinone), emodin (1,3,8-trihydroxy-6-methylanthraquinone), purpurin (1,2,4-trihydroxyanthraquinone), and rhein (1,8-dihydroxy-3-carboxyanthraquinone). Their activities were determined in terms of IC50 values, defined as the concentration that inhibits 50% of the cells under the test conditions and calculated from linear dose response plots for the parasitic protozoa, and zone of inhibition for bacteria and fungi, respectively. The results show that the different substituents on the anthraquinone ring seem to influence the relative potency. Analysis of the structure–activity relationships in protozoa indicates that the aloe-emodin and chrysazin with the highest biological activities merit further study for their potential to help treat the diseases in women and domestic and farm animals. Emodin also exhibited antifungal activity against Candida albicans. The suggested mechanism of action and the additional reported beneficial biological properties of anthraquinones suggest that they have the potential to ameliorate a broad spectrum of human diseases. Full article
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Review
Molecular Features and Metal Ions That Influence 10-23 DNAzyme Activity
Molecules 2020, 25(13), 3100; https://doi.org/10.3390/molecules25133100 - 07 Jul 2020
Cited by 4 | Viewed by 1490
Abstract
Deoxyribozymes (DNAzymes) with RNA hydrolysis activity have a tremendous potential as gene suppression agents for therapeutic applications. The most extensively studied representative is the 10-23 DNAzyme consisting of a catalytic loop and two substrate binding arms that can be designed to bind and [...] Read more.
Deoxyribozymes (DNAzymes) with RNA hydrolysis activity have a tremendous potential as gene suppression agents for therapeutic applications. The most extensively studied representative is the 10-23 DNAzyme consisting of a catalytic loop and two substrate binding arms that can be designed to bind and cleave the RNA sequence of interest. The RNA substrate is cleaved between central purine and pyrimidine nucleotides. The activity of this DNAzyme in vitro is considerably higher than in vivo, which was suggested to be related to its divalent cation dependency. Understanding the mechanism of DNAzyme catalysis is hindered by the absence of structural information. Numerous biological studies, however, provide comprehensive insights into the role of particular deoxynucleotides and functional groups in DNAzymes. Here we provide an overview of the thermodynamic properties, the impact of nucleobase modifications within the catalytic loop, and the role of different metal ions in catalysis. We point out features that will be helpful in developing novel strategies for structure determination and to understand the mechanism of the 10-23 DNAzyme. Consideration of these features will enable to develop improved strategies for structure determination and to understand the mechanism of the 10-23 DNAzyme. These insights provide the basis for improving activity in cells and pave the way for developing DNAzyme applications. Full article
(This article belongs to the Special Issue Advances in Catalytic DNA)
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Article
Quasi-Isostructural Co(II) and Ni(II) Complexes with Mefenamato Ligand: Synthesis, Characterization, and Biological Activity
Molecules 2020, 25(13), 3099; https://doi.org/10.3390/molecules25133099 - 07 Jul 2020
Cited by 3 | Viewed by 781
Abstract
Three metal complexes of mefenamato ligand 1 were synthesized: [Co2(mef)4(EtOH)2(H2O)4]: 2; [Co(mef)2(MeOH)4]∙2MeOH: 3; and [Ni(mef)2(MeOH)4]∙2MeOH: 4. Their compositions and properties were investigated [...] Read more.
Three metal complexes of mefenamato ligand 1 were synthesized: [Co2(mef)4(EtOH)2(H2O)4]: 2; [Co(mef)2(MeOH)4]∙2MeOH: 3; and [Ni(mef)2(MeOH)4]∙2MeOH: 4. Their compositions and properties were investigated by elemental analysis (EA), flame atomic absorption spectrometry (FAAS), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Crystal structures were determined by the single crystal X-ray diffraction technique. Additionally, their antioxidant and antimicrobial activity were established, thus proving good/moderate bioactivity against Gram-positive bacteria and yeasts. In the crystal structure of 2, an apical water molecule is shared between two adjacent cobalt(II) ions, resulting in the formation of a polymeric chain extending along the [100] direction. Meanwhile, structures 3 and 4 have strong intermolecular hydrogen bonds with diverse topologies that yield unique quasi-isostructural arrangements. The packing topology is reflected by the Hirshfeld surface analysis of intermolecular contacts. Full article
(This article belongs to the Special Issue Advances in Coordination Chemistry)
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Review
Unravelling the Potential of Salivary Volatile Metabolites in Oral Diseases. A Review
Molecules 2020, 25(13), 3098; https://doi.org/10.3390/molecules25133098 - 07 Jul 2020
Cited by 2 | Viewed by 1281
Abstract
Fostered by the advances in the instrumental and analytical fields, in recent years the analysis of volatile organic compounds (VOCs) has emerged as a new frontier in medical diagnostics. VOCs analysis is a non-invasive, rapid and inexpensive strategy with promising potential in clinical [...] Read more.
Fostered by the advances in the instrumental and analytical fields, in recent years the analysis of volatile organic compounds (VOCs) has emerged as a new frontier in medical diagnostics. VOCs analysis is a non-invasive, rapid and inexpensive strategy with promising potential in clinical diagnostic procedures. Since cellular metabolism is altered by diseases, the resulting metabolic effects on VOCs may serve as biomarkers for any given pathophysiologic condition. Human VOCs are released from biomatrices such as saliva, urine, skin emanations and exhaled breath and are derived from many metabolic pathways. In this review, the potential of VOCs present in saliva will be explored as a monitoring tool for several oral diseases, including gingivitis and periodontal disease, dental caries, and oral cancer. Moreover, the analytical state-of-the-art for salivary volatomics, e.g., the most common extraction techniques along with the current challenges and future perspectives will be addressed unequivocally. Full article
(This article belongs to the Special Issue Volatile Organic Compounds (VOCs): Their Meaning in Human Health)
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Article
Anticancer Potential and Capsianosides Identification in Lipophilic Fraction of Sweet Pepper (Capsicum annuum L.)
Molecules 2020, 25(13), 3097; https://doi.org/10.3390/molecules25133097 - 07 Jul 2020
Viewed by 768
Abstract
This study aimed to determine the health-promoting properties of sweet pepper by comparing the activity of fractions with variable lipophilicity. Fractions from red pericarp: aqueous (F1), 40% MeOH (F2), and 70% MeOH (F3) were analyzed for antiradical activity (with DPPH and ABTS [...] Read more.
This study aimed to determine the health-promoting properties of sweet pepper by comparing the activity of fractions with variable lipophilicity. Fractions from red pericarp: aqueous (F1), 40% MeOH (F2), and 70% MeOH (F3) were analyzed for antiradical activity (with DPPH and ABTS+•), and the contents of total phenolic compounds (TP), flavonoids (TF), and dihydroxycinnamic acids (TDHCA). The anticancer potential of the fractions was evaluated in vitro using different cancer cell lines: human colorectal carcinoma (HCT116) and PC-3 (prostate cancer cell). Fibroblast-like cells of L929 obtained from subcutaneous adipose tissue of mouse were used as normal cells. The highest content of TP, TF, and TDHCA along with the strongest antiradical activity was observed for fraction F2, while the strongest anticancer properties against PC-3 were observed in fraction F3. Fraction F3 primarily contained capsianoside derivatives, which had been isolated through chromatographic methods and identified by spectral methods. These analyses helped in identifying 8 compounds, including 3 new compounds. Full article
(This article belongs to the Section Natural Products Chemistry)
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Article
A Nano Drug Delivery System Based on Angelica sinensis Polysaccharide for Combination of Chemotherapy and Immunotherapy
Molecules 2020, 25(13), 3096; https://doi.org/10.3390/molecules25133096 - 07 Jul 2020
Cited by 1 | Viewed by 875
Abstract
Combination of chemotherapy and immunotherapy has been a promising strategy in cancer treatment. Polysaccharides from Angelica sinensis (AP), a well-known Chinese herbal medicine, have been proved to have good immunomodulatory activity. In the present study, an enzyme-sensitive tumor-targeting nano drug delivery system (AP-PP-DOX [...] Read more.
Combination of chemotherapy and immunotherapy has been a promising strategy in cancer treatment. Polysaccharides from Angelica sinensis (AP), a well-known Chinese herbal medicine, have been proved to have good immunomodulatory activity. In the present study, an enzyme-sensitive tumor-targeting nano drug delivery system (AP-PP-DOX (doxorubicin), PP stood for peptide) was constructed. In this system, Angelica polysaccharides act as not only carriers to targeted delivery of drugs to tumor tissue but also effectors to improve tumor microenvironment and enhance immune function, resulting in synergistic antitumor effect with chemotherapy drugs. The structure of this conjugate was confirmed by FI-IR and 1H-NMR. The particle size and zeta potential of the nanoparticles were 129.00 ± 3.32 nm and −28.45 ± 0.22 mV, respectively. Doxorubicin (DOX) and AP could be quickly released from the AP-PP-DOX under the presence of matrix metalloproteinase 2 (MMP2). The released DOX showed good antitumor efficacy in vitro. The treatment of released AP moiety increased the expression of IL-2, while that of IL-10 was decreased, showing potential in restoring Th1/Th2 immune balance in tumor microenvironment. In a word, this drug delivery system, with specific tissue targeting and tumor microenvironment improvement, will open a new avenue for combination treatment of cancer. Full article
(This article belongs to the Special Issue Polymer-Drug Conjugates/Prodrugs for Drug Delivery Application)
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Article
Adsorption Capacity of Vitamin B12 and Creatinine on Highly-Mesoporous Activated Carbons Obtained from Lignocellulosic Raw Materials
Molecules 2020, 25(13), 3095; https://doi.org/10.3390/molecules25133095 - 07 Jul 2020
Cited by 2 | Viewed by 723
Abstract
Enterosorbents are widely-used materials for human body detoxification, which function by immobilizing and eliminating endogenous and exogenous toxins. Here, activated carbons, obtained from the lignocellulosic raw vegetal materials of indigenous provenance, have been studied. Walnut shell and wood from local species of nuts [...] Read more.
Enterosorbents are widely-used materials for human body detoxification, which function by immobilizing and eliminating endogenous and exogenous toxins. Here, activated carbons, obtained from the lignocellulosic raw vegetal materials of indigenous provenance, have been studied. Walnut shell and wood from local species of nuts and apple-trees were carbonized, and further activated at high temperatures with water vapors in a rotary kiln. A second activation was carried out, in a fluidized bed reactor, but for shorter times. The textural properties of the samples were determined from the adsorption isotherms of nitrogen at 77 K, allowing the obtaining of highly mesoporous materials, while the adsorption capacity permitted an essential rise of six to seven times in the maximal adsorption values of the metabolites, which was determined by the reactivation process. A kinetic study of vitamin B12 and creatinine immobilization was performed, the optimal immobilization time for the apple-tree wood reactivated carbons being 2 times longer than for those originating from walnut shells. An additional investigation was also performed in specific conditions that simulate the real environment of immobilization: the temperature of a febrile human body (at the temperature T = 38 °C) and the characteristic acidity of the urinary tract and stomach (at the pH of 5.68 and 2.53, respectively). The activated carbonic adsorbents studied here, together with the results of the immobilization studies, show that these procedures can conduct a good incorporation of some endogenous metabolic products, such as vitamin B12 and creatinine, therefore presenting a good opportunity for their use as forthcoming commercial enterosorbents. Full article
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Review
Thiyl Radicals: Versatile Reactive Intermediates for Cyclization of Unsaturated Substrates
Molecules 2020, 25(13), 3094; https://doi.org/10.3390/molecules25133094 - 07 Jul 2020
Cited by 1 | Viewed by 1144
Abstract
Sulfur centered radicals are widely employed in chemical synthesis, in particular for alkene and alkyne hydrothiolation towards thioether bioconjugates. The steadfast radical chain process that enables efficient hydrothiolation has been explored in the context of cascade reactions to furnish complex molecular architectures. The [...] Read more.
Sulfur centered radicals are widely employed in chemical synthesis, in particular for alkene and alkyne hydrothiolation towards thioether bioconjugates. The steadfast radical chain process that enables efficient hydrothiolation has been explored in the context of cascade reactions to furnish complex molecular architectures. The use of thiyl radicals offers a much cheaper and less toxic alternative to the archetypal organotin-based radical methods. This review outlines the development of thiyl radicals as reactive intermediates for initiating carbocyclization cascades. Key developments in cascade cyclization methodology are presented and applications for natural product synthesis are discussed. The review provides a chronological account of the field, beginning in the early seventies up to very recent examples; a span of almost 50 years. Full article
(This article belongs to the Special Issue Advances in Radical Chemistry)
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Review
The GABAB Receptor—Structure, Ligand Binding and Drug Development
Molecules 2020, 25(13), 3093; https://doi.org/10.3390/molecules25133093 - 07 Jul 2020
Cited by 4 | Viewed by 1298
Abstract
The γ-aminobutyric acid (GABA) type B receptor (GABAB-R) belongs to class C of the G-protein coupled receptors (GPCRs). Together with the GABAA receptor, the receptor mediates the neurotransmission of GABA, the main inhibitory neurotransmitter in the central nervous system (CNS). [...] Read more.
The γ-aminobutyric acid (GABA) type B receptor (GABAB-R) belongs to class C of the G-protein coupled receptors (GPCRs). Together with the GABAA receptor, the receptor mediates the neurotransmission of GABA, the main inhibitory neurotransmitter in the central nervous system (CNS). In recent decades, the receptor has been extensively studied with the intention being to understand pathophysiological roles, structural mechanisms and develop drugs. The dysfunction of the receptor is linked to a broad variety of disorders, including anxiety, depression, alcohol addiction, memory and cancer. Despite extensive efforts, few compounds are known to target the receptor, and only the agonist baclofen is approved for clinical use. The receptor is a mandatory heterodimer of the GABAB1 and GABAB2 subunits, and each subunit is composed of an extracellular Venus Flytrap domain (VFT) and a transmembrane domain of seven α-helices (7TM domain). In this review, we briefly present the existing knowledge about the receptor structure, activation and compounds targeting the receptor, emphasizing the role of the receptor in previous and future drug design and discovery efforts. Full article
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Article
Removal of Phosphorus from Wastewater by Different Morphological Alumina
Molecules 2020, 25(13), 3092; https://doi.org/10.3390/molecules25133092 - 07 Jul 2020
Cited by 2 | Viewed by 655
Abstract
In this work, an organic-free method was used to synthesize different morphological boehmite by controlling the crystallization temperature, and alumina adsorbents were obtained by baking the boehmites at 500 °C. The alumina adsorbents were characterized by X-ray diffraction (XRD), High resolution transmission electron [...] Read more.
In this work, an organic-free method was used to synthesize different morphological boehmite by controlling the crystallization temperature, and alumina adsorbents were obtained by baking the boehmites at 500 °C. The alumina adsorbents were characterized by X-ray diffraction (XRD), High resolution transmission electron microscope (HRTEM), Fourier transform infrared (FT-IR), N2 adsorption/desorption analysis, and their phosphorus adsorption properties were comparatively investigated by a series of experiments. The results showed that the self-prepared alumina adsorbents were lamellar and fibrous material, while the industrial adsorbent was a granular material. The lamellar alumina adsorbents had the largest specific surface area and showed better phosphorus adsorption capacity. The maximum adsorption capacity could reach up to 588.2 mg·g−1; and only 0.8 g·L−1 of lamellar alumina adsorbent is needed to treat 100 mg·L−1 phosphorus solution under the Chinese level 1 discharge standard (0.5 mg·L−1). Further investigation suggests that the lamellar alumina adsorbent kept high adsorption capacity in various solution environments. Full article
(This article belongs to the Section Nanochemistry)
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Article
Pleurotus sajor-caju-Mediated Synthesis of Silver and Gold Nanoparticles Active against Colon Cancer Cell Lines: A New Era of Herbonanoceutics
Molecules 2020, 25(13), 3091; https://doi.org/10.3390/molecules25133091 - 07 Jul 2020
Cited by 10 | Viewed by 947
Abstract
Herbal medicines are widely used worldwide and much appreciated because of their fewer side effects and the ability to fight diseases at the root cause. Active ‘phyto’ ingredients require a scientific approach and a mechanism to distribute components at the target site for [...] Read more.
Herbal medicines are widely used worldwide and much appreciated because of their fewer side effects and the ability to fight diseases at the root cause. Active ‘phyto’ ingredients require a scientific approach and a mechanism to distribute components at the target site for better therapeutic results. Nanotechnology, on the other hand, has created new hope for cancer treatment but is still far from being proven in clinical settings. This article combines a unique approach to synthesis with the use of Pleurotus sajor-caju, followed by microwave irritation of silver and gold nanoparticles that ensures the capping of the active phyto ingredient and further enhances the effects of nanomedicine to fight colon cancer, thus opening a new era of what we call herbonanoceutics. The article also compares the characteristics and properties of silver (Au) and gold (Ag) nanoparticles synthesized by an in house developed novel microwave-assisted rapid green synthesis method. The as-prepared Ag NPs and Au NPs were compared using ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). Our comparative study revealed that both assemblies display face-centred cubic structures (FCCs) and are nanocrystalline in nature. The advantage of the approach was that the sizes of gold and silver were identical in range with a similar distribution pattern. This has helped us to study the activity against colon cancer cell line (HCT-116) without incoherence since size plays a key role in the application. More specifically, morphological changes, cell viability, the production of reactive oxygen species (ROS) and the fragmentation of DNA have been further reported to assess better the results obtained with the two metals. Our results suggest that the newly adopted synthesis method may ensure the dual benefits from phyto ingredients which further enhances the effectiveness of advanced nanomedicine. Full article
(This article belongs to the Special Issue Green Synthesis and Application of Gold and Silver Nanoparticles)
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Article
Assembly and Redox-Rich Hydride Chemistry of an Asymmetric Mo2S2 Platform
Molecules 2020, 25(13), 3090; https://doi.org/10.3390/molecules25133090 - 07 Jul 2020
Viewed by 749
Abstract
Although molybdenum sulfide materials show promise as electrocatalysts for proton reduction, the hydrido species proposed as intermediates remain poorly characterized. We report herein the synthesis, reactions and spectroscopic properties of a molybdenum-hydride complex featuring an asymmetric Mo2S2 core. This molecule [...] Read more.
Although molybdenum sulfide materials show promise as electrocatalysts for proton reduction, the hydrido species proposed as intermediates remain poorly characterized. We report herein the synthesis, reactions and spectroscopic properties of a molybdenum-hydride complex featuring an asymmetric Mo2S2 core. This molecule displays rich redox chemistry with electrochemical couples at E½ = −0.45, −0.78 and −1.99 V vs. Fc/Fc+. The corresponding hydrido-complexes for all three redox levels were isolated and characterized crystallographically. Through an analysis of solid-state bond metrics and DFT calculations, we show that the electron-transfer processes for the two more positive couples are centered predominantly on the pyridinediimine supporting ligand, whereas for the most negative couple electron-transfer is mostly Mo-localized. Full article
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Article
New Paracyclophanylthiazoles with Anti-Leukemia Activity: Design, Synthesis, Molecular Docking, and Mechanistic Studies
Molecules 2020, 25(13), 3089; https://doi.org/10.3390/molecules25133089 - 07 Jul 2020
Cited by 3 | Viewed by 721
Abstract
A new series of methyl 2-(2-(4′-[2.2]paracyclophanyl)-hydrazinylidene)-3-substituted-4-oxothiazolidin-5-ylidene)acetates 3af were synthesized from the reaction of paracyclophanyl-acylthiosemicarbazides 2af with dimethyl acetylenedicarboxylate. Based upon nuclear magnetic resonance (NMR), infrared (IR), and mass spectra (HRMS), the structure of the obtained products was elucidated. X-ray [...] Read more.
A new series of methyl 2-(2-(4′-[2.2]paracyclophanyl)-hydrazinylidene)-3-substituted-4-oxothiazolidin-5-ylidene)acetates 3af were synthesized from the reaction of paracyclophanyl-acylthiosemicarbazides 2af with dimethyl acetylenedicarboxylate. Based upon nuclear magnetic resonance (NMR), infrared (IR), and mass spectra (HRMS), the structure of the obtained products was elucidated. X-ray structure analysis was also used as unambiguous tool to elucidate the structure of the products. The target compounds 3af were screened against 60 cancer cell lines. They displayed anticancer activity against a leukemia subpanel, namely, RPMI-8226 and SR cell lines. The activity of compound 3a was found as the most cytotoxic potency against 60 cancer cell lines. Consequently, it was selected for further five doses analysis according to National Cancer Institute (NCI) protocol. The cytotoxic effect showed selectivity ratios ranging between 0.63 and 1.28 and between 0.58 and 5.89 at the GI50 and total growth inhibition (TGI) levels, respectively. Accordingly, compound 3a underwent further mechanistic study against the most sensitive leukemia RPMI-8226 and SR cell lines. It showed antiproliferation with IC50 = 1.61 ± 0.04 and 1.11 ± 0.03 µM against RPMI-8226 and SR cell lines, respectively. It also revealed a remarkable tubulin inhibitory activity, compared to colchicine with IC50 = 4.97 µM/mL. Caspase-3, BAX, and Bcl-2 assays for 3a using annexin V-FITC staining revealed significant pro-apoptotic activity. Furthermore, multidrug-resistant leukemia SR cells were used to show better resistance indices (1.285 ng/mL, 1.15-fold) than the reference. Docking studies with β-tubulin indicate that most of the tested compounds illustrated good binding at the colchicine binding site of the enzyme, especially for compound 3a, which made several interactions better than that of the reference colchicine. Full article
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Article
Antioxidant Activity of Selected Phenolic Acids–Ferric Reducing Antioxidant Power Assay and QSAR Analysis of the Structural Features
Molecules 2020, 25(13), 3088; https://doi.org/10.3390/molecules25133088 - 07 Jul 2020
Cited by 5 | Viewed by 970
Abstract
Phenolic acids are naturally occurring compounds that are known for their antioxidant and antiradical activity. We present experimental and theoretical studies on the antioxidant potential of the set of 22 phenolic acids with different models of hydroxylation and methoxylation of aromatic rings. Ferric [...] Read more.
Phenolic acids are naturally occurring compounds that are known for their antioxidant and antiradical activity. We present experimental and theoretical studies on the antioxidant potential of the set of 22 phenolic acids with different models of hydroxylation and methoxylation of aromatic rings. Ferric reducing antioxidant power assay was used to evaluate this property. 2,3-dihydroxybenzoic acid was found to be the strongest antioxidant, while mono hydroxylated and methoxylated structures had the lowest activities. A comprehensive structure–activity investigation with density functional theory methods elucidated the influence of compounds topology, resonance stabilization, and intramolecular hydrogen bonding on the exhibited activity. The key factor was found to be a presence of two or more hydroxyl groups being located in ortho or para position to each other. Finally, the quantitative structure–activity relationship approach was used to build a multiple linear regression model describing the dependence of antioxidant activity on structure of compounds, using features exclusively related to their topology. Coefficients of determination for training set and for the test set equaled 0.9918 and 0.9993 respectively, and Q2 value for leave-one-out was 0.9716. In addition, the presented model was used to predict activities of phenolic acids that haven’t been tested here experimentally. Full article
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Article
Characteristic Metabolic Changes of the Crust from Dry-Aged Beef Using 2D NMR Spectroscopy
Molecules 2020, 25(13), 3087; https://doi.org/10.3390/molecules25133087 - 07 Jul 2020
Cited by 4 | Viewed by 941
Abstract
Two-dimensional quantitative nuclear magnetic resonance (2D qNMR)-based metabolomics was performed to understand characteristic metabolic profiles in different aging regimes (crust from dry-aged beef, inner edible flesh of dry-aged beef, and wet-aged beef striploin) over 4 weeks. Samples were extracted using 0.6 M perchlorate [...] Read more.
Two-dimensional quantitative nuclear magnetic resonance (2D qNMR)-based metabolomics was performed to understand characteristic metabolic profiles in different aging regimes (crust from dry-aged beef, inner edible flesh of dry-aged beef, and wet-aged beef striploin) over 4 weeks. Samples were extracted using 0.6 M perchlorate to acquire polar metabolites. Partial least squares-discriminant analysis showed a good cumulative explained variation (R2 = 0.967) and predictive ability (Q2 = 0.935). Metabolites of crust and aged beef (dry- and wet-aged beef) were separated in the first week and showed a completely different aspect in the second week via NMR-based multivariable analyses. Moreover, NMR-based multivariable analyses could be used to distinguish the method, degree, and doneness of beef aging. Among them, the crust showed more unique metabolic changes that accelerated proteolysis (total free amino acids and biogenic amines) and inosine 5′-monophosphate depletion than dry-aged beef and generated specific microbial catabolites (3-indoxyl sulfate) and γ-aminobutyric acid (GABA), while asparagine, glutamine, tryptophan, and glucose in the crust were maintained or decreased. Compared to the crust, dry-aged beef showed similar patterns of biogenic amines, as well as bioactive compounds and GABA, without a decrease in free amino acids and glucose. Based on these results, the crust allows the inner dry-aged beef to be aged similarly to wet-aged beef without microbial effects. Thus, 2D qNMR-based metabolomic techniques could provide complementary information about biochemical factors for beef aging. Full article
(This article belongs to the Special Issue NMR-Based Metabolomics)
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Article
Accumulation of Saponins in Underground Parts of Panax vietnamensis at Different Ages Analyzed by HPLC-UV/ELSD
Molecules 2020, 25(13), 3086; https://doi.org/10.3390/molecules25133086 - 07 Jul 2020
Cited by 2 | Viewed by 1248
Abstract
Panax vietnamensis (PV), a wild Panax species discovered in Vietnam in 1973, has been increasingly overexploited due to its economic value and therapeutic uses. This resulted in the development of PV cultivation to meet the market demand. There is little information on the [...] Read more.
Panax vietnamensis (PV), a wild Panax species discovered in Vietnam in 1973, has been increasingly overexploited due to its economic value and therapeutic uses. This resulted in the development of PV cultivation to meet the market demand. There is little information on the accumulation of saponins in PV during cultivation, but this information could serve as an indication of the appropriate harvest time. In this study we developed an HPLC-UV/ELSD method to simultaneously determine the content of 10 characteristic saponins in PV from 2–7 years old, including G-Rb1, G-Rd, G-Rg1, G-Re, N-R1, M-R1, M-R2, V-R2, V-R11, and p-RT4. The result indicated that from 2 to 5 years, the content of saponins in PV rhizome and radix increase 3.02 and 4.2 times, respectively, whereas from 5 to 7 years, no significant changes were observed. Hence, our study suggests that after 5 years of growth could be considered as an appropriate time for PV to be harvested. Among the analyzed saponins, G-Rg1, G-Rb1, G-Rd, and especially M-R2 were the major saponins that contributed to the change of PV’s saponin content through the years. In addition, the developed and validated HPLC method was proven to be reliable and effective for quality control of PV. Full article
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Article
Prediction of Chromatographic Elution Order of Analytical Mixtures Based on Quantitative Structure-Retention Relationships and Multi-Objective Optimization
Molecules 2020, 25(13), 3085; https://doi.org/10.3390/molecules25133085 - 06 Jul 2020
Viewed by 834
Abstract
Prediction of the retention time from the molecular structure using quantitative structure-retention relationships is a powerful tool for the development of methods in reversed-phase HPLC. However, its fundamental limitation lies in the fact that low error in the prediction of the retention time [...] Read more.
Prediction of the retention time from the molecular structure using quantitative structure-retention relationships is a powerful tool for the development of methods in reversed-phase HPLC. However, its fundamental limitation lies in the fact that low error in the prediction of the retention time does not necessarily guarantee a prediction of the elution order. Here, we propose a new method for the prediction of the elution order from quantitative structure-retention relationships using multi-objective optimization. Two case studies were evaluated: (i) separation of organic molecules in a Supelcosil LC-18 column, and (ii) separation of peptides in seven columns under varying conditions. Results have shown that, when compared to predictions based on the conventional model, the relative root mean square error of the elution order decreases by 48.84%, while the relative root mean square error of the retention time increases by 4.22% on average across both case studies. The predictive ability in terms of both retention time and elution order and the corresponding applicability domains were defined. The models were deemed stable and robust with few to no structural outliers. Full article
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Article
Iron’s Wake: The Performance of Quantum Mechanical-Derived Versus General-Purpose Force Fields Tested on a Luminescent Iron Complex
Molecules 2020, 25(13), 3084; https://doi.org/10.3390/molecules25133084 - 06 Jul 2020
Cited by 2 | Viewed by 1001
Abstract
Recently synthetized iron complexes have achieved long-lived excited states and stabilities which are comparable, or even superior, to their ruthenium analogues, thus representing an eco-friendly and cheaper alternative to those materials based on rare metals. Most of computational tools which could help unravel [...] Read more.
Recently synthetized iron complexes have achieved long-lived excited states and stabilities which are comparable, or even superior, to their ruthenium analogues, thus representing an eco-friendly and cheaper alternative to those materials based on rare metals. Most of computational tools which could help unravel the origin of this large efficiency rely on ab-initio methods which are not able, however, to capture the nanosecond time scale underlying these photophysical processes and the influence of their realistic environment. Therefore, it exists an urgent need of developing new low-cost, but still accurate enough, computational methodologies capable to deal with the steady-state and transient spectroscopy of transition metal complexes in solution. Following this idea, here we focus on the comparison between general-purpose transferable force-fields (FFs), directly available from existing databases, and specific quantum mechanical derived FFs (QMD-FFs), obtained in this work through the Joyce procedure. We have chosen a recently reported FeIII complex with nanosecond excited-state lifetime as a representative case. Our molecular dynamics (MD) simulations demonstrated that the QMD-FF nicely reproduces the structure and the dynamics of the complex and its chemical environment within the same precision as higher cost QM methods, whereas general-purpose FFs failed in this purpose. Although in this particular case the chemical environment plays a minor role on the photo physics of this system, these results highlight the potential of QMD-FFs to rationalize photophysical phenomena provided an accurate QM method to derive its parameters is chosen. Full article
(This article belongs to the Special Issue Recent Advances in the Chemistry of Organoiron Compounds)
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Article
Thiabendazole and Thiabendazole-Formic Acid Solvate: A Computational, Crystallographic, Spectroscopic and Thermal Study
Molecules 2020, 25(13), 3083; https://doi.org/10.3390/molecules25133083 - 06 Jul 2020
Cited by 2 | Viewed by 1693
Abstract
Thiabendazole (TBZ) is a substance which has been receiving multiple important applications in several domains, from medicine and pharmaceutical sciences, to agriculture and food industry. Here, a comprehensive multi-technique investigation on the molecular and crystal properties of TBZ is reported. In addition, a [...] Read more.
Thiabendazole (TBZ) is a substance which has been receiving multiple important applications in several domains, from medicine and pharmaceutical sciences, to agriculture and food industry. Here, a comprehensive multi-technique investigation on the molecular and crystal properties of TBZ is reported. In addition, a new solvate of the compound is described and characterized structurally, vibrationally and thermochemically for the first time. Density functional theory (DFT) calculations were used to investigate the conformational space of thiabendazole (TBZ), revealing the existence of two conformers, the most stable planar trans form and a double-degenerated-by-symmetry gauche form, which is ~30 kJ mol−1 higher in energy than the trans conformer. The intramolecular interactions playing the major roles in determining the structure of the TBZ molecule and its conformational preferences were characterized. The UV-visible and infrared spectra of the isolated molecule (most stable trans conformer) were also calculated, and their assignment undertaken. The information obtained for the isolated molecule provided a strong basis for the understanding of the intermolecular interactions and properties of the crystalline compound. In particular, the infrared spectrum for the isolated molecule was compared with that of crystalline TBZ and the differences between the two spectra were interpreted in terms of the major intermolecular interactions existing in the solid state. The analysis of the infrared spectral data was complemented with vibrational results of up-to-date fully-periodic DFT calculations and Raman spectroscopic studies. The thermal behavior of TBZ was also investigated using differential scanning calorimetry (DSC) and thermogravimetry. Furthermore, a new TBZ–formic acid solvate [2-(1,3-thiazol-4-yl)benzimidazolium formate formic acid solvate] was synthesized and its crystal structure determined by X-ray diffraction. The Hirshfeld method was used to explore the intermolecular interactions in the crystal of the new TBZ solvate, comparing them with those present in the neat TBZ crystal. Raman spectroscopy and DSC studies were also carried out on the solvate to further characterize this species and investigate its temperature-induced desolvation. Full article
(This article belongs to the Section Physical Chemistry)
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Article
Effect of a =X-NH-Fragment, (X = C, N), on Z/E Isomerization and ON/OFF Functionality of Isatin Arylhydrazones, ((Arylamino)Methylene)Indolin-2-Ones and Their Anions
Molecules 2020, 25(13), 3082; https://doi.org/10.3390/molecules25133082 - 06 Jul 2020
Viewed by 660
Abstract
The subject of this work was the study of thermally and photochemically stimulated ZE isomerization and hydrazo ↔ azo tautomerism of Z- and E-isomers of isatin arylhydrazones and ((arylamino)methylene)indolin-2-ones and their anions. Using NMR, UV-Vis spectroscopy, kinetic measurements, and [...] Read more.
The subject of this work was the study of thermally and photochemically stimulated ZE isomerization and hydrazo ↔ azo tautomerism of Z- and E-isomers of isatin arylhydrazones and ((arylamino)methylene)indolin-2-ones and their anions. Using NMR, UV-Vis spectroscopy, kinetic measurements, and HPLC, we studied the relationship of structure, (Z- and E-isomers), of these compounds and hydrazo=azo tautomerism. The ON/OFF functionality of these compounds and their anions using light to stimulate switching between ON and OFF states was investigated. We pointed out the characterization of the effect of =N- and =CH- structural fragments and aryl structure on ON and OFF states of isatin arylhydrazones and ((arylamino)methylene)indolin-2-ones. Full article
(This article belongs to the Special Issue New Studies of Photoisomerization)
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Article
Effective Removal of Pb(II) Ions by Electrospun PAN/Sago Lignin-Based Activated Carbon Nanofibers
Molecules 2020, 25(13), 3081; https://doi.org/10.3390/molecules25133081 - 06 Jul 2020
Cited by 4 | Viewed by 819
Abstract
Heavy metal pollution, such as lead, can cause contamination of water resources and harm human life. Many techniques have been explored and utilized to overcome this problem, with adsorption technology being the most common strategies for water treatment. In this study, carbon nanofibers, [...] Read more.
Heavy metal pollution, such as lead, can cause contamination of water resources and harm human life. Many techniques have been explored and utilized to overcome this problem, with adsorption technology being the most common strategies for water treatment. In this study, carbon nanofibers, polyacrylonitrile (PAN)/sago lignin (SL) carbon nanofibers (PAN/SL CNF) and PAN/SL activated carbon nanofibers (PAN/SL ACNF), with a diameter approximately 300 nm, were produced by electrospinning blends of polyacrylonitrile and sago lignin followed by thermal and acid treatments and used as adsorbents for the removal of Pb(II) ions from aqueous solutions. The incorporation of biodegradable and renewable SL in PAN/SL blends fibers produces the CNF with a smaller diameter than PAN only but preserves the structure of CNF. The adsorption of Pb(II) ions on PAN/SL ACNF was three times higher than that of PAN/SL CNF. The enhanced removal was due to the nitric acid treatment that resulted in the formation of surface oxygenated functional groups that promoted the Pb(II) ions adsorption. The best-suited adsorption conditions that gave the highest percentage removal of 67%, with an adsorption capacity of 524 mg/g, were 40 mg of adsorbent dosage, 125 ppm of Pb(II) solution, pH 5, and a contact time of 240 min. The adsorption data fitted the Langmuir isotherm and the pseudo-second-order kinetic models, indicating that the adsorption is a monolayer, and is governed by the availability of the adsorption sites. With the adsorption capacity of 588 mg/g, determined via the Langmuir isotherm model, the study demonstrated the potential of PAN/SL ACNFs as the adsorbent for the removal of Pb(II) ions from aqueous solution. Full article
(This article belongs to the Special Issue Electrospinning Technology and Electrospun Nanofibers)
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Article
Potentilla alba Extracts Affect the Viability and Proliferation of Non-Cancerous and Cancerous Colon Human Epithelial Cells
Molecules 2020, 25(13), 3080; https://doi.org/10.3390/molecules25133080 - 06 Jul 2020
Cited by 2 | Viewed by 1082
Abstract
The aim of this study was to determine the anti-tumor activity of extracts isolated from Potentilla alba L. on human colon cancer cells of the HT-29 line and on non-cancer colon epithelial cells of the CCD 841 CoTr line. The research methods we [...] Read more.
The aim of this study was to determine the anti-tumor activity of extracts isolated from Potentilla alba L. on human colon cancer cells of the HT-29 line and on non-cancer colon epithelial cells of the CCD 841 CoTr line. The research methods we used to determine the cytotoxic and proliferative properties were 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and neutral red (NR) assays, the ability to produce nitric oxide, the Griess method, and the biochemical properties like 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods indicating reduction activity of tested samples. In order to obtain a phytochemical profile of the different extracts an analytical method based on liquid chromatography-photodiode array detection-electrospray ionization ion-trap time-of-flight mass spectrometry (LC-PDA-ESI-MS/TOF) was applied. Finally, the effects of the extracts on the morphology and cell counts were assessed by May–Grünwald–Giemsa staining. After a comprehensive analysis of all the experiments, the extracts were found to demonstrate cytotoxic properties, they stimulated the division of non-cancer cells, and they were able to scavenge free radicals. In the NR method, the cell viability dropped to approximately 80% compared to the control. In the MTT assay, tumor cell proliferation decreased to 9.5% compared to the control. Therefore, we concluded that this plant has medical potential. Full article
(This article belongs to the Special Issue Biological Activities of Natural Products)
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Article
New Terpendole Congeners, Inhibitors of Sterol O-Acyltransferase, Produced by Volutella citrinella BF-0440
Molecules 2020, 25(13), 3079; https://doi.org/10.3390/molecules25133079 - 06 Jul 2020
Viewed by 748
Abstract
New terpendoles N-P (1–3) were isolated along with 8 structurally related known compounds including terpendoles and voluhemins from a culture broth of the fungus Volutella citrinella BF-0440. The structures of 1–3 were elucidated using various spectroscopic experiments including 1D- and 2D-NMR. [...] Read more.
New terpendoles N-P (1–3) were isolated along with 8 structurally related known compounds including terpendoles and voluhemins from a culture broth of the fungus Volutella citrinella BF-0440. The structures of 1–3 were elucidated using various spectroscopic experiments including 1D- and 2D-NMR. All compounds 1–3 contained a common indole–diterpene backbone. Compounds 2 and 3 had 7 and 6 consecutive ring systems with an indole ring, respectively, whereas 1 had a unique indolinone plus 4 consecutive ring system. Compounds 2 and 3 inhibited both sterol O-acyltransferase 1 and 2 isozymes, but 1 lost the inhibitory activity. Structure–activity relationships of fungal indole–diterpene compounds are discussed. Full article
(This article belongs to the Section Natural Products Chemistry)
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Article
A Drug Content, Stability Analysis, and Qualitative Assessment of Pharmacists’ Opinions of Two Exemplar Extemporaneous Formulations
Molecules 2020, 25(13), 3078; https://doi.org/10.3390/molecules25133078 - 06 Jul 2020
Cited by 2 | Viewed by 783
Abstract
Despite a decline in the number of active pharmaceutical ingredients prepared extemporaneously using proprietary products, there remains a need for such products in the community (for example, liquid medicines for paediatrics which may be otherwise commercially unavailable). A lack of experience and quality [...] Read more.
Despite a decline in the number of active pharmaceutical ingredients prepared extemporaneously using proprietary products, there remains a need for such products in the community (for example, liquid medicines for paediatrics which may be otherwise commercially unavailable). A lack of experience and quality assurance systems may have diminished pharmacist’s confidence in the extemporaneous preparation process; therefore, pharmacists were asked to prepare two proprietary products, omeprazole and amlodipine. The resulting products were characterised in terms of variability in drug quantity, stability, particle size and antimicrobial properties. Furthermore, a self-administered questionnaire was used to assess 10 pharmacists’ opinions on the perceived complexity of the extemporaneous compounding process and their overall confidence in the final extemporaneously compounded products. Drug content studies revealed that 88.5% and 98.0% of the desired drug content was obtained for omeprazole and amlodipine, respectively. Antimicrobial properties were maintained for both drugs, however variability in particle size, particularly for amlodipine, was evident between formulations. While pharmacists who partook in the study had some or high confidence in the final products, they reported difficulty formulating the suspensions. Findings from this study provide insight into pharmacists’ views on two extemporaneously prepared products and highlight the variability obtained in preparations prepared by different pharmacists. Full article
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Article
Bioassay-Guided Separation of Centipeda minima Using Comprehensive Linear Gradient Centrifugal Partition Chromatography
Molecules 2020, 25(13), 3077; https://doi.org/10.3390/molecules25133077 - 06 Jul 2020
Viewed by 990
Abstract
A comprehensive linear gradient solvent system for centrifugal partition chromatography (CPC) was developed for the bioassay-guided isolation of natural compounds. The gradient solvent system consisted of three different ternary biphasic solvents types: n-hexane–acetonitrile–water (10:2:8, v/v), ethyl acetate–acetonitrile–water (10:2:8, v [...] Read more.
A comprehensive linear gradient solvent system for centrifugal partition chromatography (CPC) was developed for the bioassay-guided isolation of natural compounds. The gradient solvent system consisted of three different ternary biphasic solvents types: n-hexane–acetonitrile–water (10:2:8, v/v), ethyl acetate–acetonitrile–water (10:2:8, v/v), and water-saturated n-butanol–acetonitrile–water (10:2:8, v/v). The lower phase of the n-hexane–acetonitrile–water (10:2:8, v/v) was used as the stationary phase, while its upper phase, as well as ethyl acetate–acetonitrile–water (10:2:8), and water-saturated n-butanol–acetonitrile–water (10:2:8, v/v) were pumped to generate a linear gradient elution, increasing the mobile phase polarity. We used the gradient CPC to identify antioxidant response elements (AREs), inducing compounds from Centipeda minima, using an ARE-luciferase assay in HepG2 cells, which led to the purification of the active molecules 3-methoxyquercetin and brevilin A. The developed CPC solvent systems allow the separation and isolation of compounds with a wide polarity range, allowing active molecule identification in the complex crude extract of natural products. Full article
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Article
A New Validated Potentiometric Method for Sulfite Assay in Beverages Using Cobalt(II) Phthalocyanine as a Sensory Recognition Element
Molecules 2020, 25(13), 3076; https://doi.org/10.3390/molecules25133076 - 06 Jul 2020
Cited by 1 | Viewed by 575
Abstract
A simple potentiometric sensor is described for accurate, precise, and rapid determination of sulfite additives in beverages. The sensor is based on the use of cobalt phthalocyanine as a recognition material, dispersed in a plasticized poly(vinyl chloride) matrix membrane. o-Nitrophenyl octyl ether [...] Read more.
A simple potentiometric sensor is described for accurate, precise, and rapid determination of sulfite additives in beverages. The sensor is based on the use of cobalt phthalocyanine as a recognition material, dispersed in a plasticized poly(vinyl chloride) matrix membrane. o-Nitrophenyl octyl ether (o-NPOE) as a membrane solvent and tri-dodecylmethyl- ammonium chloride (TDMAC) as ion discriminators are used as membrane additives. Under the optimized conditions, sulfite ion is accurately and precisely measured under batch and flow injection modes of analysis. The sensor exhibits fast and linear response for 1.0 × 10−2–1.0 × 10−6 M (800–0.08 µg/mL) and 1.0 × 10−1–5.0 × 10−5 M (8000–4 µg/mL) sulfite with Nernstian slopes of −27.4 ± 0.3 and −23.7 ± 0.6 mV/concentration decade under static and hydrodynamic modes of operation, respectively. Results in good agreement with the standard iodometric method are obtained.Validation of the assay method is examined in details including precision, accuracy, bias, trueness, repeatability, reproducibility, and uncertainty and good performance characteristics of the method are obtained. The sensor response is stable over the pH range of 5 to 7 without any significant interference from most common anions. The advantages offered by the proposed sensor (i.e., wide range of assay, high accuracy and precision, low detection limit, reasonable selectivity, long term response stability, fast response, and long life span and absence of any sample pretreatment steps) suggest its use in the quality control/quality assurance routine tests in beverages industries, toxicological laboratories and by inspection authorities. Full article
(This article belongs to the Section Analytical Chemistry)
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Review
Herbal Remedies as Potential in Cartilage Tissue Engineering: An Overview of New Therapeutic Approaches and Strategies
Molecules 2020, 25(13), 3075; https://doi.org/10.3390/molecules25133075 - 06 Jul 2020
Cited by 2 | Viewed by 1211
Abstract
It is estimated that by 2023, approximately 20% of the population of Western Europe and North America will suffer from a degenerative joint disease commonly known as osteoarthritis (OA). During the development of OA, pro-inflammatory cytokines are one of the major causes that [...] Read more.
It is estimated that by 2023, approximately 20% of the population of Western Europe and North America will suffer from a degenerative joint disease commonly known as osteoarthritis (OA). During the development of OA, pro-inflammatory cytokines are one of the major causes that drive the production of inflammatory mediators and thus of matrix-degrading enzymes. OA is a challenging disease for doctors due to the limitation of the joint cartilage’s capacity to repair itself. Though new treatment approaches, in particular with mesenchymal stem cells (MSCs) that integrate the tissue engineering (TE) of cartilage tissue, are promising, they are not only expensive but more often do not lead to the regeneration of joint cartilage. Therefore, there is an increasing need for novel, safe, and more effective alternatives to promote cartilage joint regeneration and TE. Indeed, naturally occurring phytochemical compounds (herbal remedies) have a great anti-inflammatory, anti-oxidant, and anabolic potential, and they have received much attention for the development of new therapeutic strategies for the treatment of inflammatory diseases, including the prevention of age-related OA and cartilage TE. This paper summarizes recent research on herbal remedies and their chondroinductive and chondroprotective effects on cartilage and progenitor cells, and it also emphasizes the possibilities that exist in this research area, especially with regard to the nutritional support of cartilage regeneration and TE, which may not benefit from non-steroidal anti-inflammatory drugs (NSAIDs). Full article
(This article belongs to the Collection Molecular Medicine)
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