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Molecules, Volume 23, Issue 7 (July 2018)

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Open AccessArticle Phytochemical Screening of Quaking Aspen (Populus tremuloides) Extracts by UPLC-QTOF-MS and Evaluation of their Antimicrobial Activity
Molecules 2018, 23(7), 1739; https://doi.org/10.3390/molecules23071739 (registering DOI)
Received: 29 June 2018 / Revised: 9 July 2018 / Accepted: 12 July 2018 / Published: 16 July 2018
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Abstract
The continual emergence of pathogen resistance is a recurring challenge and pushes for the development of antimicrobial compounds. Here, we investigated compounds from quaking aspen trees (Populus tremuloides) as potential antimicrobial agents. Several extractions using different solvents were realized, and corresponding
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The continual emergence of pathogen resistance is a recurring challenge and pushes for the development of antimicrobial compounds. Here, we investigated compounds from quaking aspen trees (Populus tremuloides) as potential antimicrobial agents. Several extractions using different solvents were realized, and corresponding antimicrobial activity was tested against eight microorganisms. Results revealed that polar extraction solvents including water, ethanol and methanol gave the best extraction yields (>15.07%). Minimal inhibition concentration (MIC) and minimal bactericidal/fungicidal concentration (MBC/MFC) demonstrated that water extracts had the best antimicrobial activity by a weak to moderate inhibition of growth of all eight tested microorganisms in addition to having a bactericidal effect on three of them. The quaking aspen methanol extract also displayed antimicrobial activity but to a lower level than the water extract. Ultra-performance liquid chromatography quadrupole time-of flight mass spectrometry (UPLC-QTOF-MS) analysis led to the identification of 92 compounds, mainly polyphenols in both extracts, with 22 molecules previously known for their antimicrobial properties. According to the relative abundance, 4-hydroxybenzaldehyde (5.44% in methanol extract) and kaempferol (5.03% in water extract) were the most abundant antimicrobial compounds. Among antimicrobial molecules identified, nine were from the flavonoid family. The results of our study demonstrate the interest of using quaking aspen as source of antimicrobial compounds. Full article
(This article belongs to the Section Chemical Biology)
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Open AccessArticle Antitumor Effects and Delivery Profiles of Menahydroquinone-4 Prodrugs with Ionic or Nonionic Promoiety to Hepatocellular Carcinoma Cells
Molecules 2018, 23(7), 1738; https://doi.org/10.3390/molecules23071738 (registering DOI)
Received: 27 June 2018 / Revised: 14 July 2018 / Accepted: 15 July 2018 / Published: 16 July 2018
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Abstract
Hepatocellular carcinoma (HCC) shows poor prognosis owing to its very frequent recurrence even after curative treatment. Thus, an effective and safe long-term chemopreventive agent is strongly in demand. Menahydroquinone-4 (MKH) is an active form of menaquinone-4 (MK-4, vitamin K2) that is
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Hepatocellular carcinoma (HCC) shows poor prognosis owing to its very frequent recurrence even after curative treatment. Thus, an effective and safe long-term chemopreventive agent is strongly in demand. Menahydroquinone-4 (MKH) is an active form of menaquinone-4 (MK-4, vitamin K2) that is involved in the synthesis of vitamin K-dependent proteins in the liver. We hypothesized that efficient delivery of MKH might be critical to regulate HCC proliferation. The discovery of a suitable prodrug targeting HCC in terms of delivery and activation could reduce the clinical dose of MK-4 and maximize efficacy and safety. We previously showed that MKH dimethylglycinate (MKH-DMG) enables effective delivery of MKH into HCC cells and exhibits strong antitumor effects compared with MK-4. In this study, we prepared anionic MKH hemi-succinate (MKH-SUC) and non-ionic MKH acetate (MKH-ACT), in addition to cationic MKH-DMG, and evaluated MKH delivery profiles and antitumor effects in vitro. MKH-SUC showed the highest uptake and the most efficient release of MKH among the examined compounds and exhibited rapid and strong antitumor effects. These results indicate that MKH-SUC might have a good potential as an MKH delivery system for HCC that overcomes the limitations of MK-4 as a clinical chemopreventive agent. Full article
(This article belongs to the Special Issue Targeted Prodrugs 2018)
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Open AccessArticle The Analysis of the Physicochemical Properties of Benzocaine Polymorphs
Molecules 2018, 23(7), 1737; https://doi.org/10.3390/molecules23071737 (registering DOI)
Received: 29 June 2018 / Revised: 12 July 2018 / Accepted: 13 July 2018 / Published: 16 July 2018
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Abstract
The study was a pioneering attempt to assess the influence of the structural polymorphism (forms I, II, III) of benzocaine on its solubility, apparent solubility, and chemical stability, which are vital parameters for preformulation and formulation work. The impact of differences in the
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The study was a pioneering attempt to assess the influence of the structural polymorphism (forms I, II, III) of benzocaine on its solubility, apparent solubility, and chemical stability, which are vital parameters for preformulation and formulation work. The impact of differences in the solubility of selected polymorphs of benzocaine on their permeability through artificial biological membranes (PAMPA system) was evaluated. The polymorphs of benzocaine were obtained by means of techniques commonly used for the preparation of various pharmaceutical dosage forms: ball milling, micro milling, and cryogenic grinding, which allowed for the appearance or preservation of form III, the initial conformation of benzocaine. Ball milling resulted in the conversion of form III to I, whereas micro milling yielded form II. As a result of cryogenic grinding, form III of benzocaine was preserved. The identification of all polymorphic forms of benzocaine was confirmed via X-ray powder diffraction (PXRD) supported by FT-IR spectroscopy coupled with density functional theory (DFT) calculations. The differences in solubility, dissolution, and permeability through artificial biological membranes resulting from the polymorphic forms of benzocaine were established by using chromatographic determinations. Accelerated stability tests indicated that all polymorphic forms were chemically stable at a required level. Full article
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Open AccessArticle Quick Multi-Class Determination of Residues of Antimicrobial Veterinary Drugs in Animal Muscle by LC-MS/MS
Molecules 2018, 23(7), 1736; https://doi.org/10.3390/molecules23071736 (registering DOI)
Received: 4 June 2018 / Revised: 10 July 2018 / Accepted: 11 July 2018 / Published: 16 July 2018
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Abstract
On the basis of the highly sensitive and selective liquid chromatography-tandem mass spectrometry technique, a generic extraction solvent and a sample dilution method was developed for the residue analysis of different polar veterinary drugs known as fluoroquinolones, sulfonamides, macrolides, and tiamulin in chicken
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On the basis of the highly sensitive and selective liquid chromatography-tandem mass spectrometry technique, a generic extraction solvent and a sample dilution method was developed for the residue analysis of different polar veterinary drugs known as fluoroquinolones, sulfonamides, macrolides, and tiamulin in chicken muscle. The results showed that the matrix-matched calibration curves of all 10 compounds were in an effective linear relationship (r2 ≥ 0.997) in the range of 0.2–100 μg L−1. At three spiking levels of 2 (5), 50, and 100 μg kg−1, average recoveries of analytes were between 67.1% and 96.6% with relative standard deviations of intra-day and inter-day below 20%. The limits of detection and limits of quantification of the method were in the range of 0.3–2.0 μg kg−1 and 2.0–5.0 μg kg−1, respectively, which were significantly lower than their maximum residue limits. In addition, the intensity of the target analytes and its corresponding matrix effects were obviously related to the sample dilution times (matrix concentration). There were no significant differences (p > 0.05) in the average content of almost any of the analytes in medicated chickens between this method and the method in the literature for determining analytes. Lastly, the proposed method was successfully applied for the simultaneous analysis of 10 common veterinary drugs in food animal muscle tissues. Full article
(This article belongs to the Special Issue Trends in Veterinary Drug Analysis: Multiresidue and Omic Approaches)
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Open AccessArticle Study on the Photoluminescent and Thermal Properties of Zinc Complexes with a N6O4 Macrocyclic Ligand
Molecules 2018, 23(7), 1735; https://doi.org/10.3390/molecules23071735 (registering DOI)
Received: 1 April 2018 / Revised: 14 May 2018 / Accepted: 8 July 2018 / Published: 16 July 2018
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Abstract
Reactions between a N6O4 macrocyclic ligand (L1) and several Zn(II) salts (trifluoromethane sulfonate, p-toluenesulfonate, acetate, benzoate, o-, m- or p-hydroxybenzoate) led to the formation of seven complexes, [Zn2L1 (DMSO)4](OSO
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Reactions between a N6O4 macrocyclic ligand (L1) and several Zn(II) salts (trifluoromethane sulfonate, p-toluenesulfonate, acetate, benzoate, o-, m- or p-hydroxybenzoate) led to the formation of seven complexes, [Zn2L1 (DMSO)4](OSO2CF3)4 (1), [Zn2(p-OSO2PhCH3)4L1] (2), [Zn2(OCOCH3)4L1] (3), [Zn2(OCOPh)4L1] (4), [Zn2(o-OCOPhOH)4L1] (5), [Zn2(m-OCOPhOH)4 L1] (6) and [Zn2(p-OCOPhOH)4 L1] (7), which were characterized by elemental analysis, 1H-NMR, 13C-NMR, IR, fluorescence spectroscopies and single crystal X-ray diffraction. In 1, the Zn atom is pentacoordinated with a N3O2 irregular trigonal bipyramidal coordination environment, like the geometries in compounds 37, whereas in structure 2 the metal atom is envisaged as possessing a distorted N3O3 octahedronal environment. All the compounds show interesting photoluminescent properties in solid states and solutions in DMF and DMSO, which are reported along with their TG-DTA thermal decomposition processes, UV-vis absorption spectroscopy and fluorescence quantum yields in DMF and DMSO. Full article
(This article belongs to the Section Inorganic Chemistry)
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Open AccessArticle Phytotoxic Activity of Metabolites Isolated from Rutstroemia sp.n., the Causal Agent of Bleach Blonde Syndrome on Cheatgrass (Bromus tectorum)
Molecules 2018, 23(7), 1734; https://doi.org/10.3390/molecules23071734 (registering DOI)
Received: 25 June 2018 / Revised: 10 July 2018 / Accepted: 12 July 2018 / Published: 16 July 2018
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Abstract
A fungal pathogen soon to be described as Rutstroemia capillus-albis (Rutstroemiaceae, Helotiales, Leotiomycetes) has been identified as the causal agent of ‘bleach blonde syndrome’ on the invasive annual grass weed Bromus tectorum (cheatgrass) in western North America. This apparently common but previously undescribed
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A fungal pathogen soon to be described as Rutstroemia capillus-albis (Rutstroemiaceae, Helotiales, Leotiomycetes) has been identified as the causal agent of ‘bleach blonde syndrome’ on the invasive annual grass weed Bromus tectorum (cheatgrass) in western North America. This apparently common but previously undescribed disease causes premature senescence and sterility, but does not affect seed germination or seedling emergence and growth. This study investigated whether the new species produces phytotoxins that could be implicated in pathogenesis. The compounds 9-O-methylfusarubin, 9-O-methylbostrycoidin, 5-O-methylnectriafurone, trans-methyl-p-coumarate and terpestacin were isolated from the solid culture of this fungus. The undescribed absolute stereochemistry at C-3 of 9-O-methylfusarubin and at C-1’ of 5-O-methylnectriafurone were assigned by applying electronic and vibrational circular dichroism (ECD and VCD) combined with computational methods and the advanced Mosher’s method, respectively. The first three listed compounds are naphtoquinone pigments, while terpestacin is a sesterterpene, and trans-methyl-p-coumarate could be the product of an unusual fungal phenylpropanoid biosynthesis pathway. In a juvenile plant immersion bioassay, both 9-O-methylfusarubin and terpestacin proved to be highly toxic at 10−4 M, causing wilting and plant death within 10 days. This finding suggests that these two compounds could play a role in pathogenesis on B. tectorum. Full article
(This article belongs to the Special Issue Natural Products Used as Foods and Food Ingredients)
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Open AccessReview The Biological and Biophysical Properties of the Spider Peptide Gomesin
Molecules 2018, 23(7), 1733; https://doi.org/10.3390/molecules23071733 (registering DOI)
Received: 1 July 2018 / Revised: 11 July 2018 / Accepted: 12 July 2018 / Published: 16 July 2018
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Abstract
This review summarises the current knowledge of Gomesin (Gm), an 18-residue long, cationic anti-microbial peptide originally isolated from the haemocytes of the Brazilian tarantula Acanthoscurria gomesiana. The peptide shows potent cytotoxic activity against clinically relevant microbes including Gram-positive and Gram-negative bacteria, fungi, and
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This review summarises the current knowledge of Gomesin (Gm), an 18-residue long, cationic anti-microbial peptide originally isolated from the haemocytes of the Brazilian tarantula Acanthoscurria gomesiana. The peptide shows potent cytotoxic activity against clinically relevant microbes including Gram-positive and Gram-negative bacteria, fungi, and parasites. In addition, Gm shows in-vitro and in-vivo anti-cancer activities against several human and murine cancers. The peptide exerts its cytotoxic activity by permeabilising cell membranes, but the underlying molecular mechanism of action is still unclear. Due to its potential as a therapeutic agent, the structure and membrane-binding properties, as well as the leakage and cytotoxic activities of Gm have been studied using a range of techniques. This review provides a summary of these studies, with a particular focus on biophysical characterisation studies of peptide variants that have attempted to establish a structure-activity relationship. Future studies are still needed to rationalise the binding affinity and cell-type-specific selectivity of Gm and its variants, while more pre-clinical studies are required to develop Gm into a therapeutically useful peptide. Full article
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Open AccessArticle Synthesis of Nitrogen-Rich Polymers by Click Polymerization Reaction and Gas Sorption Property
Molecules 2018, 23(7), 1732; https://doi.org/10.3390/molecules23071732 (registering DOI)
Received: 16 June 2018 / Revised: 10 July 2018 / Accepted: 13 July 2018 / Published: 16 July 2018
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Abstract
Microporous organic polymers (MOPs) are promising materials for gas sorption because of their intrinsic and permanent porosity, designable framework, and low density. The introduction of nitrogen-rich building block in MOPs will greatly enhance the gas sorption capacity. Here, we report the synthesis of
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Microporous organic polymers (MOPs) are promising materials for gas sorption because of their intrinsic and permanent porosity, designable framework, and low density. The introduction of nitrogen-rich building block in MOPs will greatly enhance the gas sorption capacity. Here, we report the synthesis of MOPs from the 2,4,6-tris(4-ethynylphenyl)-1,3,5-triazine unit and aromatic azides linkers by click polymerization reaction. Fourier transform infrared (FTIR) and solid-state 13C CP-MAS (Cross Polarization-Magic Angle Spinning) NMR confirm the formation of the polymers. CMOP-1 and CMOP-2 exhibit microporous networks with a BET (Brunauer–Emmett–Teller) surface area of 431 m2·g−1 and 406 m2·g−1 and a narrow pore size distribution under 1.2 nm. Gas sorption isotherms including CO2 and H2 were measured. CMOP-1 stores a superior CO2 level of 1.85 mmol·g−1 at 273 K/1.0 bar, and an H2 uptake of up to 2.94 mmol·g−1 at 77 K/1.0 bar, while CMOP-2, with its smaller surface area, shows a lower CO2 adsorption capacity of 1.64 mmol·g−1 and an H2 uptake of 2.48 mmol·g−1. In addition, I2 vapor adsorption was tested at 353 K. CMOP-1 shows a higher gravimetric load of 160 wt%. Despite the moderate surface area, the CMOPs display excellent sorption ability for CO2 and I2 due to the nitrogen-rich content in the polymers. Full article
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Open AccessArticle The Cartesian Product and Join Graphs on Edge-Version Atom-Bond Connectivity and Geometric Arithmetic Indices
Molecules 2018, 23(7), 1731; https://doi.org/10.3390/molecules23071731
Received: 25 May 2018 / Revised: 27 June 2018 / Accepted: 6 July 2018 / Published: 16 July 2018
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Abstract
The Cartesian product and join are two classical operations in graphs. Let dL(G)(e) be the degree of a vertex e in line graph L(G) of a graph G. The edge versions of
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The Cartesian product and join are two classical operations in graphs. Let dL(G)(e) be the degree of a vertex e in line graph L(G) of a graph G. The edge versions of atom-bond connectivity (ABCe) and geometric arithmetic (GAe) indices of G are defined as efE(L(G))dL(G)(e)+dL(G)(f)2dL(G)(e)×dL(G)(f) and efE(L(G))2dL(G)(e)×dL(G)(f)dL(G)(e)+dL(G)(f), respectively. In this paper, ABCe and GAe indices for certain Cartesian product graphs (such as PnPm, PnCm and PnSm) are obtained. In addition, ABCe and GAe indices of certain join graphs (such as Cm+Pn+Sr, Pm+Pn+Pr, Cm+Cn+Cr and Sm+Sn+Sr) are deduced. Our results enrich and revise some known results. Full article
(This article belongs to the Special Issue Molecular Computing and Bioinformatics)
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Open AccessArticle Solvent Extraction and Identification of Active Anticariogenic Metabolites in Piper cubeba L. through 1H-NMR-Based Metabolomics Approach
Molecules 2018, 23(7), 1730; https://doi.org/10.3390/molecules23071730
Received: 28 March 2018 / Revised: 7 July 2018 / Accepted: 10 July 2018 / Published: 16 July 2018
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Abstract
The aim of this study was to determine the effects of different solvents for extraction, liquid–liquid partition, and concentrations of extracts and fractions of Piper cubeba L. on anticariogenic; antibacterial and anti-inflammatory activity against oral bacteria. Furthermore, 1H-Nuclear Magnetic Resonance (NMR) coupled
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The aim of this study was to determine the effects of different solvents for extraction, liquid–liquid partition, and concentrations of extracts and fractions of Piper cubeba L. on anticariogenic; antibacterial and anti-inflammatory activity against oral bacteria. Furthermore, 1H-Nuclear Magnetic Resonance (NMR) coupled with multivariate data analysis (MVDA) was applied to discriminate between the extracts and fractions and examine the metabolites that correlate to the bioactivities. All tested bacteria were susceptible to Piper cubeba L. extracts and fractions. Different solvents extraction, liquid–liquid partition and concentrations of extracts and fractions have partially influenced the antibacterial activity. MTT assay showed that P. cubeba L. extracts and fractions were not toxic to RAW 264.7 cells at selected concentrations. Anti-inflammatory activity evaluated by nitric oxide (NO) production in lipopolysaccharide (LPS) stimulated cells showed a reduction in NO production in cells treated with P. cubeba L. extracts and fractions, compared to those without treatment. Twelve putative metabolites have been identified, which are (1) cubebin, (2) yatein, (3) hinokinin, (4) dihydrocubebin, (5) dihydroclusin, (6) cubebinin, (7) magnosalin, (8) p-cymene, (9) piperidine, (10) cubebol, (11) d-germacrene and (12) ledol. Different extraction and liquid–liquid partition solvents caused separation in principal component analysis (PCA) models. The partial least squares (PLS) models showed that higher anticariogenic activity was related more to the polar solvents, despite some of the active metabolites also present in the non-polar solvents. Hence, P. cubeba L. extracts and fractions exhibited antibacterial and anti-inflammatory activity and have potential to be developed as the anticariogenic agent. Full article
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Open AccessArticle Causal Discovery Combining K2 with Brain Storm Optimization Algorithm
Molecules 2018, 23(7), 1729; https://doi.org/10.3390/molecules23071729
Received: 12 May 2018 / Revised: 7 July 2018 / Accepted: 9 July 2018 / Published: 16 July 2018
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Abstract
Exploring and detecting the causal relations among variables have shown huge practical values in recent years, with numerous opportunities for scientific discovery, and have been commonly seen as the core of data science. Among all possible causal discovery methods, causal discovery based on
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Exploring and detecting the causal relations among variables have shown huge practical values in recent years, with numerous opportunities for scientific discovery, and have been commonly seen as the core of data science. Among all possible causal discovery methods, causal discovery based on a constraint approach could recover the causal structures from passive observational data in general cases, and had shown extensive prospects in numerous real world applications. However, when the graph was sufficiently large, it did not work well. To alleviate this problem, an improved causal structure learning algorithm named brain storm optimization (BSO), is presented in this paper, combining K2 with brain storm optimization (K2-BSO). Here BSO is used to search optimal topological order of nodes instead of graph space. This paper assumes that dataset is generated by conforming to a causal diagram in which each variable is generated from its parent based on a causal mechanism. We designed an elaborate distance function for clustering step in BSO according to the mechanism of K2. The graph space therefore was reduced to a smaller topological order space and the order space can be further reduced by an efficient clustering method. The experimental results on various real-world datasets showed our methods outperformed the traditional search and score methods and the state-of-the-art genetic algorithm-based methods. Full article
(This article belongs to the Special Issue Molecular Computing and Bioinformatics)
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Open AccessArticle Development of Conjugate Addition of Lithium Dialkylcuprates to Thiochromones: Synthesis of 2-Alkylthiochroman-4-ones and Additional Synthetic Applications
Molecules 2018, 23(7), 1728; https://doi.org/10.3390/molecules23071728
Received: 16 June 2018 / Revised: 5 July 2018 / Accepted: 13 July 2018 / Published: 15 July 2018
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Abstract
Lithium dialkylcuprates undergo conjugate addition to thiochromones to afford 2-alkylthiochroman-4-ones in good yields. This approach provide an efficient and general synthetic approach to privileged sulfur-containing structural motifs and valuable precursors for many pharmaceuticals, starting from common substrates-thiochromones. Good yields of 2-alkyl-substituted thiochroman-4-ones are
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Lithium dialkylcuprates undergo conjugate addition to thiochromones to afford 2-alkylthiochroman-4-ones in good yields. This approach provide an efficient and general synthetic approach to privileged sulfur-containing structural motifs and valuable precursors for many pharmaceuticals, starting from common substrates-thiochromones. Good yields of 2-alkyl-substituted thiochroman-4-ones are attained with lithium dialkylcuprates, lithium alkylcyanocuprates or substoichiometric amount of copper salts. The use of commercially available inexpensive alkyllithium reagents will expedite the synthesis of a large library of 2-alkyl substituted thiochroman-4-ones for additional synthetic applications. Full article
(This article belongs to the Special Issue Organometallic Catalysis in Organic Synthesis)
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Open AccessArticle Microwave-Assisted Synthesis of Some Potential Bioactive Imidazolium-Based Room-Temperature Ionic Liquids
Molecules 2018, 23(7), 1727; https://doi.org/10.3390/molecules23071727
Received: 11 June 2018 / Revised: 12 July 2018 / Accepted: 13 July 2018 / Published: 15 July 2018
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Abstract
An environmentally-friendly and easy synthesis of a series of novel functionalized imidazolium-based ionic liquids (ILs) is described under both the conventional procedure and microwave irradiation. The structures of newly synthesized room-temperature ionic liquids (RTILs) were established by different spectral analyses. All ILs (
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An environmentally-friendly and easy synthesis of a series of novel functionalized imidazolium-based ionic liquids (ILs) is described under both the conventional procedure and microwave irradiation. The structures of newly synthesized room-temperature ionic liquids (RTILs) were established by different spectral analyses. All ILs (114) were screened for their in vitro antimicrobial activity against a panel of clinically isolated bacteria. The results of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) showed that some of the tested ILs are very promising anti-bacterial agents especially those containing an alkyl chain with a phenyl group (most notably 1, 2, 12, and 13). Full article
(This article belongs to the Special Issue Ionic Liquids for Chemical and Biochemical Applications)
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Open AccessArticle Novel High-Sensitivity Racetrack Surface Plasmon Resonance Sensor Modified by Graphene
Molecules 2018, 23(7), 1726; https://doi.org/10.3390/molecules23071726
Received: 18 June 2018 / Revised: 10 July 2018 / Accepted: 12 July 2018 / Published: 14 July 2018
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Abstract
In order to overcome the existing challenges presented by conventional sensors, including their large size, a complicated preparation process, and difficulties filling the sensing media, a novel high-sensitivity plasmonic resonator sensor which is composed of two graphene-modified straight waveguides, two metallic layers, and
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In order to overcome the existing challenges presented by conventional sensors, including their large size, a complicated preparation process, and difficulties filling the sensing media, a novel high-sensitivity plasmonic resonator sensor which is composed of two graphene-modified straight waveguides, two metallic layers, and a racetrack nanodisk resonator is proposed in this study. The transmission characteristics, which were calculated by the finite element theory, were used to further analyze the sensing properties. The results of quantitative analysis show that the proposed plasmonic sensor generates two resonance peaks for the different incident wavelengths, and both resonance peaks can be tuned by temperature. In addition, after optimizing the structural parameters of the resonator, the Q value and the refractive sensitivity reached 21.5 and 1666.67 nmRIU–1, respectively. Compared with other studies, these values translate to a better performance. Furthermore, a temperature sensitivity of 2.33 nm/5°C was achieved, which allows the sensor to be easily applied to practical detection. The results of this study can broaden the useful range for a nanometer-scale temperature sensor with ultrafast real-time detection and resistance to electromagnetic interference. Full article
(This article belongs to the Special Issue Graphene Nanocomposites)
Open AccessArticle Construction of Thermo-Responsive Elastin-Like Polypeptides (ELPs)-Aggregation-Induced-Emission (AIE) Conjugates for Temperature Sensing
Molecules 2018, 23(7), 1725; https://doi.org/10.3390/molecules23071725
Received: 10 June 2018 / Revised: 11 July 2018 / Accepted: 12 July 2018 / Published: 14 July 2018
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Abstract
In this work, an aggregation-induced emission (AIE) molecule (tetraphenylethene derivative, TPE-COOH) was conjugated to elastin-like polypeptides (ELPs40) via an amide bond to form ELPs40-TPE. The successful synthesis of ELPs40-TPE was confirmed by Circular Dichroism spectroscopy, gel electrophoresis, UV-vis absorption, and fluorescence emission spectroscopy.
[...] Read more.
In this work, an aggregation-induced emission (AIE) molecule (tetraphenylethene derivative, TPE-COOH) was conjugated to elastin-like polypeptides (ELPs40) via an amide bond to form ELPs40-TPE. The successful synthesis of ELPs40-TPE was confirmed by Circular Dichroism spectroscopy, gel electrophoresis, UV-vis absorption, and fluorescence emission spectroscopy. ELPs40-TPE possessed both amphiphilicity and the features of an AIE, and the fluorescence intensity was dependent on the local temperature. The Hela cells imaging indicated that ELPs40-TPE has great potential for bio-imaging applications because of its advantages of high fluorescence intensity, good water-solubility, and remarkable biocompatibility. Full article
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