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Molecules, Volume 22, Issue 12 (December 2017)

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Cover Story (view full-size image) Bi-functional Nb–Beta zeolite catalysts display high efficiency for the catalytic wet oxidation of [...] Read more.
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Open AccessArticle Access to New Cytotoxic Quinone-Amino Acid Conjugates Linked through A Vinylic Spacer from 2-Acylnaphthoquinones and Methyl 3-Aminocrotonate
Molecules 2017, 22(12), 2281; https://doi.org/10.3390/molecules22122281
Received: 28 November 2017 / Revised: 16 December 2017 / Accepted: 19 December 2017 / Published: 20 December 2017
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Abstract
The reaction of 2-acetyl- and 2-benzoyl-1,4-naphthoquinone with (Z)-methyl 3-(hydroxymethyl)aminocrotonate proceeds through a formal [3+3] process to yield the corresponding 1,2-dihydrobenzisoquinolinequinones in 63% and 72% yield, respectively. The reactions of 2-acyl-1,4-naphthoquinone with enaminones, derived from diverse l- and d-amino acid
[...] Read more.
The reaction of 2-acetyl- and 2-benzoyl-1,4-naphthoquinone with (Z)-methyl 3-(hydroxymethyl)aminocrotonate proceeds through a formal [3+3] process to yield the corresponding 1,2-dihydrobenzisoquinolinequinones in 63% and 72% yield, respectively. The reactions of 2-acyl-1,4-naphthoquinone with enaminones, derived from diverse l- and d-amino acid methyl esters, produced the corresponding naphthoquinone amino acids conjugates bonded through a vinyl spacer in the yields range 40–71%. The presence of not-separable isomers of the naphthoquinone amino acids conjugates in the 1H- and 13C-NMR spectra is explained by the existence of conformational isomers generated by hindered rotation of the substituent bonded to the quinone double bond. These new naphthoquinone amino acids conjugates were screened in vitro on normal and cancer cell lines and showed moderate cytotoxic activities. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Adsorption of Cd (II) on Modified Granular Activated Carbons: Isotherm and Column Study
Molecules 2017, 22(12), 2280; https://doi.org/10.3390/molecules22122280
Received: 15 November 2017 / Revised: 13 December 2017 / Accepted: 14 December 2017 / Published: 20 December 2017
Cited by 1 | PDF Full-text (1462 KB) | HTML Full-text | XML Full-text
Abstract
In this work, equilibrium and dynamic adsorption tests of cadmium Cd (II) on activated carbons derived from different oxidation treatments (with either HNO3, H2O2, or NaOCl, corresponding to GACoxN, GACoxP, and GACoxCl samples) are presented. The oxidation
[...] Read more.
In this work, equilibrium and dynamic adsorption tests of cadmium Cd (II) on activated carbons derived from different oxidation treatments (with either HNO3, H2O2, or NaOCl, corresponding to GACoxN, GACoxP, and GACoxCl samples) are presented. The oxidation treatments determined an increase in the surface functional groups (mainly the acidic ones) and a decrease in the pHPZC (except for the GACoxCl sample). A slight alteration of the textural parameters was also observed, which was more significant for the GACoxCl sample, in terms of a decrease of both Brunauer-Emmett-Teller (BET) surface area and micropore volume. Adsorption isotherms were determined for all the adsorbents and a significant increase in the adsorption performances of the oxidized samples with respect to the parent material was observed. The performances ranking was GACoxCl > GACoxP > GACoxN > GAC, likely due to the chemical surface properties of the adsorbents. Dynamic tests in a fixed bed column were carried out in terms of breakthrough curves at constant Cd inlet concentration and flow rate. GACoxCl and GACoxN showed a significantly higher value of the breakpoint time, likely due to the higher adsorption capacity. Finally, the dynamic tests were analyzed in light of a kinetic model. In the adopted experimental conditions, the results showed that mass transfer is controlled by internal pore diffusion, in which surface diffusion plays a major role. Full article
(This article belongs to the Section Green Chemistry)
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Open AccessArticle Labdane-Type Diterpenes, Galangalditerpenes A–C, with Melanogenesis Inhibitory Activity from the Fruit of Alpinia galanga
Molecules 2017, 22(12), 2279; https://doi.org/10.3390/molecules22122279
Received: 24 November 2017 / Revised: 16 December 2017 / Accepted: 18 December 2017 / Published: 20 December 2017
Cited by 2 | PDF Full-text (1996 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In our continuing study of biologically active natural products from the fruit of Alpinia galanga (Zingiberaceae), we newly isolated three new labdane-type diterpenes, termed galangalditerpenes A–C (13), along with four known sesquiterpenes (47) and two
[...] Read more.
In our continuing study of biologically active natural products from the fruit of Alpinia galanga (Zingiberaceae), we newly isolated three new labdane-type diterpenes, termed galangalditerpenes A–C (13), along with four known sesquiterpenes (47) and two diterpenes (8 and 9). The stereostructures of 13 were elucidated on the basis of their spectroscopic properties. The melanogenesis inhibitory activities in theophylline-stimulated murine B16 melanoma 4A5 cells of these isolates, including the new diterpenes (13, IC50 = 4.4, 8.6, and 4.6 μM, respectively), were found to be more than 6–87-fold higher than that of arbutin (174 μM), a commercially available positive control. Full article
(This article belongs to the Special Issue Diversity of Terpenoids)
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Open AccessCommunication A Water Cluster Conduit in Crystal
Molecules 2017, 22(12), 2278; https://doi.org/10.3390/molecules22122278
Received: 25 October 2017 / Revised: 13 December 2017 / Accepted: 14 December 2017 / Published: 20 December 2017
Cited by 1 | PDF Full-text (1352 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The crystal structure of compound (1), [CuCl(phen)(H2NCH2COO)]∙4H2O, reveals an unusual hydrogen-bond water cluster aggregate T6(2)6(2). Four water molecules in (1) form an isolated water cluster, [(H2O)14]n, resembling
[...] Read more.
The crystal structure of compound (1), [CuCl(phen)(H2NCH2COO)]∙4H2O, reveals an unusual hydrogen-bond water cluster aggregate T6(2)6(2). Four water molecules in (1) form an isolated water cluster, [(H2O)14]n, resembling a “phenanthro-[1,2]phenanthrene polymer structure shape” along the ac plane. The two face-face parallel [(H2O)14]n planes are bridged by Cl atoms in [CuCl(phen) (H2NCH2COO)] with a strong O-H∙∙∙Cl hydrogen bond to form a water cluster conduit. Full article
(This article belongs to the Section Inorganic Chemistry)
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Open AccessReview PP2A as the Main Node of Therapeutic Strategies and Resistance Reversal in Triple-Negative Breast Cancer
Molecules 2017, 22(12), 2277; https://doi.org/10.3390/molecules22122277
Received: 3 November 2017 / Revised: 7 December 2017 / Accepted: 19 December 2017 / Published: 20 December 2017
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Abstract
Triple negative breast cancer (TNBC), is defined as a type of tumor lacking the expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). The ER, PR and HER2 are usually the molecular therapeutic targets for breast
[...] Read more.
Triple negative breast cancer (TNBC), is defined as a type of tumor lacking the expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). The ER, PR and HER2 are usually the molecular therapeutic targets for breast cancers, but they are ineffective for TNBC because of their negative expressions, so chemotherapy is currently the main treatment strategy in TNBC. However, drug resistance remains a major impediment to TNBC chemotherapeutic treatment. Recently, the protein phosphatase 2A (PP2A) has been found to regulate the phosphorylation of some substrates involved in the relevant target of TNBC, such as cell cycle control, DNA damage responses, epidermal growth factor receptor, immune modulation and cell death resistance, which may be the effective therapeutic strategies or influence drug sensitivity to TNBCs. Furthermore, PP2A has also been found that could induce ER re-expression in ER-negative breast cancer cells, and which suggests PP2A could promote the sensitivity of tamoxifen to TNBCs as a resistance reversal agent. In this review, we will summarize the potential therapeutic value of PP2A as the main node in developing targeting agents, disrupting resistance or restoring drug sensitivity in TNBC. Full article
(This article belongs to the Special Issue Counteracting Drug Resistant Mechanisms in Cancer)
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Open AccessArticle UPLC Quantitative Analysis of Multi-Components by Single Marker and Quality Evaluation of Polygala tenuifolia Wild. Extracts
Molecules 2017, 22(12), 2276; https://doi.org/10.3390/molecules22122276
Received: 16 November 2017 / Revised: 11 December 2017 / Accepted: 15 December 2017 / Published: 20 December 2017
Cited by 2 | PDF Full-text (2668 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The quality control of Polygala tenuifolia Wild. is a major challenge in its clinical application. In this paper, a new strategy for the quality evaluation of P. tenuifolia extracts was verified through reverse-phase ultra-performance liquid chromatography (UPLC). The quantitative analysis of multi-components by
[...] Read more.
The quality control of Polygala tenuifolia Wild. is a major challenge in its clinical application. In this paper, a new strategy for the quality evaluation of P. tenuifolia extracts was verified through reverse-phase ultra-performance liquid chromatography (UPLC). The quantitative analysis of multi-components by a single marker (QAMS) was conducted with 3,6′-disinapoyl sucrose as an internal reference substance. Eight components (i.e., sibiricose A5, sibiricose A6, glomeratose A, tenuifoliside A, tenuifoliside B, tenuifoliside C, sibiricaxanthone B, and polygalaxanthone III) were determined based on the relative correction factors. The concentrations of these components were also determined by applying a conventional external standard method. The cosine value confirmed the consistency of the two methods (cosine ratio value >0.999920). Hierarchical cluster analysis, radar plots, and discriminant analysis were performed to classify 23 batches of P. tenuifolia extracts from Shanxi, Hebei, and Shaanxi in China. Results revealed that QAMS combined with radar plots and multivariate data analysis could accurately measure and clearly distinguish the different quality samples of P. tenuifolia. Hence, QAMS is a feasible and promising method for the quality control of P. tenuifolia. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Increasing Antioxidant Activity and Protein Digestibility in Phaseolus vulgaris and Avena sativa by Fermentation with the Pleurotus ostreatus Fungus
Molecules 2017, 22(12), 2275; https://doi.org/10.3390/molecules22122275
Received: 7 November 2017 / Revised: 12 December 2017 / Accepted: 16 December 2017 / Published: 20 December 2017
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Abstract
The aim of the research was to determine the impact of fermentation with Pleurotus ostreatus on kidney beans, black beans, and oats. The results indicate that the fungus has a positive effect on the substrates when compared to the controls. The antioxidant activity
[...] Read more.
The aim of the research was to determine the impact of fermentation with Pleurotus ostreatus on kidney beans, black beans, and oats. The results indicate that the fungus has a positive effect on the substrates when compared to the controls. The antioxidant activity (39.5% on kidney beans and 225% on oats in relation to the controls) and content of total polyphenols (kidney beans three times higher regarding the controls) increased significantly by the presence of the fungus mycelium, even after simulated digestion. There was a significant increase in protein digestibility (from 39.99 to 48.13% in black beans, 44.06 to 69.01% in kidney beans, and 63.25 to 70.01% in oats) and a decrease of antinutrient tannins (from 65.21 to 22.07 mg in black beans, 35.54 to 23.37 in kidney beans, and 55.67 to 28.11 in oats) as well as an increase in the contents of some essential amino acids. Overall, this fermentation treatment with Pleurotus ostreatus improved the nutritional quality of cereals and legumes, making them potential ingredients for the elaboration and/or fortification of foods for human nutrition. Full article
(This article belongs to the Special Issue Extractable and Non-Extractable Antioxidants)
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Open AccessArticle Zinc Ion Removal on Hybrid Pectin-Based Beads Containing Modified Poly(Methyl Methacrylate) Waste
Molecules 2017, 22(12), 2274; https://doi.org/10.3390/molecules22122274
Received: 16 November 2017 / Revised: 13 December 2017 / Accepted: 16 December 2017 / Published: 20 December 2017
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Abstract
A new hybrid sorbent in the form of round beads containing modified poly(methyl methacrylate) (PMMA) waste immobilized in pectin and crosslinked with calcium ions was prepared. A previously obtained and characterized powdered poly(methyl methacrylate)–based sorbent was used. Batch and column studies on the
[...] Read more.
A new hybrid sorbent in the form of round beads containing modified poly(methyl methacrylate) (PMMA) waste immobilized in pectin and crosslinked with calcium ions was prepared. A previously obtained and characterized powdered poly(methyl methacrylate)–based sorbent was used. Batch and column studies on the new material’s sorption-desorption properties were performed. Two kinetic models (pseudo-first- and pseudo-second-order) and three isotherms (Langmuir, Langmuir bisite and Freundlich) were used to describe the results. Breakthrough and elution curves were also obtained. Nitric, hydrochloric, and sulfuric acid of various concentrations were used in the desorption studies. Higher sorption affinity of zinc(II) ions to hybrid sorbent than to pectin alone, reflected by higher values of the Langmuir and Freundlich model parameters, was observed. The maximum sorption capacities, calculated based on the best-fitted models, were 50.2 mg/g (Langmuir bisite) and 42.2 mg/g (Langmuir) for hybrid and only pectin beads, respectively. The stripping of Zn ions using 0.1 M solutions of mineral acids was similarly effective in the case of both sorbents. The mass balance calculated for the column studies showed about 100% recovery of zinc in a sorption-desorption cycle. By applying the hybrid sorbent under the studied conditions it is possible to purify Zn in water to the level permitted by law and concentrate Zn(II) ions by about 60 times. Full article
(This article belongs to the Special Issue Polysaccharide-based Materials)
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Open AccessArticle Modulation of the Selectivity in Anions Recognition Processes by Combining Hydrogen- and Halogen-Bonding Interactions
Molecules 2017, 22(12), 2273; https://doi.org/10.3390/molecules22122273
Received: 17 November 2017 / Revised: 11 December 2017 / Accepted: 18 December 2017 / Published: 20 December 2017
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Abstract
Most of the halogen bonding receptors for anions described use halogen bonding binding sites solely in the anion recognition process; only a few examples report the study of anion receptors in which the halogen bonding interaction has been used in combination with any
[...] Read more.
Most of the halogen bonding receptors for anions described use halogen bonding binding sites solely in the anion recognition process; only a few examples report the study of anion receptors in which the halogen bonding interaction has been used in combination with any other non-covalent interaction. With the aims to extend the knowledge in the behaviour of this kind of mixed receptors, we report here the synthesis and the anion recognition and sensing properties of a new halogen- and hydrogen- bonding receptor which binds anions by the cooperation of both non-covalent interactions. Fluorescence studies showed that the behaviour observed in the anion recognition sensing is similar to the one previously described for the halogen analogue and is quite different to the hydrogen one. On the other hand, the association constants obtained by 1H-NMR data demonstrate that the mixed halogen- and hydrogen-bonding receptor is more selective for SO42− anion than the halogen or hydrogen analogues. Full article
(This article belongs to the Special Issue Halogen Bonds and Beyond)
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Open AccessArticle Activation of Recombinantly Expressed l-Amino Acid Oxidase from Rhizoctonia solani by Sodium Dodecyl Sulfate
Molecules 2017, 22(12), 2272; https://doi.org/10.3390/molecules22122272
Received: 10 November 2017 / Revised: 15 December 2017 / Accepted: 18 December 2017 / Published: 20 December 2017
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Abstract
l-Amino acid oxidases (l-AAO) catalyze the oxidative deamination of l-amino acids to the corresponding α-keto acids. The non-covalently bound cofactor FAD is reoxidized by oxygen under formation of hydrogen peroxide. We expressed an active l-AAO from the fungus
[...] Read more.
l-Amino acid oxidases (l-AAO) catalyze the oxidative deamination of l-amino acids to the corresponding α-keto acids. The non-covalently bound cofactor FAD is reoxidized by oxygen under formation of hydrogen peroxide. We expressed an active l-AAO from the fungus Rhizoctonia solani as a fusion protein in E. coli. Treatment with small amounts of the detergent sodium dodecyl sulfate (SDS) stimulated the activity of the enzyme strongly. Here, we investigated whether other detergents and amphiphilic molecules activate 9His-rsLAAO1. We found that 9His-rsLAAO1 was also activated by sodium tetradecyl sulfate. Other detergents and fatty acids were not effective. Moreover, effects of SDS on the oligomerization state and the protein structure were analyzed. Native and SDS-activated 9His-rsLAAO1 behaved as dimers by size-exclusion chromatography. SDS treatment induced an increase in hydrodynamic radius as observed by size-exclusion chromatography and dynamic light scattering. The activated enzyme showed accelerated thermal inactivation and an exposure of additional protease sites. Changes in tryptophan fluorescence point to a more hydrophilic environment. Moreover, FAD fluorescence increased and a lower concentration of sulfites was sufficient to form adducts with FAD. Taken together, these data point towards a more open conformation of SDS-activated l-amino acid oxidase facilitating access to the active site. Full article
(This article belongs to the Special Issue Flavoenzymes)
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Open AccessArticle Thermal and Antioxidant Properties of Polysaccharides Sequentially Extracted from Mulberry Leaves (Morus alba L.)
Molecules 2017, 22(12), 2271; https://doi.org/10.3390/molecules22122271
Received: 30 November 2017 / Revised: 16 December 2017 / Accepted: 17 December 2017 / Published: 20 December 2017
Cited by 9 | PDF Full-text (2762 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Polysaccharides from natural plant products are gaining considerable attention due to their multi-faceted health effects, as well their functional applications in food production. We reported the sequential extraction of mulberry leaf polysaccharides (MLPs) with hot buffer (HBSS), chelating agent (CHSS), dilute alkali (DASS)
[...] Read more.
Polysaccharides from natural plant products are gaining considerable attention due to their multi-faceted health effects, as well their functional applications in food production. We reported the sequential extraction of mulberry leaf polysaccharides (MLPs) with hot buffer (HBSS), chelating agent (CHSS), dilute alkali (DASS) and concentrated alkali (CASS), in order to obtain polysaccharide fractions. Monosaccharide analysis proved that galactose (27.07%) and arabinose (25.99%) were the major sugars in HBSS, whereas arabinose (30.55%) was the major sugar in CHSS, and glucose was the major sugar in DASS (24.96%) and CASS (27.51%). The molecular weights of the polysaccharide fractions were 7.812 × 103 (HBSS), 3.279 × 103 (CHSS), 6.912 × 103 (DASS), and 1.408 × 103 kDa (CASS). HBSS and CASS showed the largest peak temperature and the highest endothermic enthalpy, respectively. Different antioxidant assays showed that the MLPs possessed appreciable antioxidant activities in a dose-dependent manner. At 5 mg/mL, HBSS and DASS possessed the largest 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activity (96.82%). HBSS exhibited the highest reducing power, and DASS rendered the strongest ABTS radical scavenging activity (99.69%). CHSS performed the best hydroxyl radical scavenging activity (64.22%) and Fe2+-chelating ability (96.36%). Our results suggested that MLPs could be a promising source of natural antioxidants for use in the food, pharmaceutical, and cosmetic industries. Full article
(This article belongs to the Special Issue Polysaccharide-based Materials)
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Open AccessArticle Novel Mixed-Type Inhibitors of Protein Tyrosine Phosphatase 1B. Kinetic and Computational Studies
Molecules 2017, 22(12), 2262; https://doi.org/10.3390/molecules22122262
Received: 21 November 2017 / Revised: 13 December 2017 / Accepted: 16 December 2017 / Published: 20 December 2017
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Abstract
The Atlas of Diabetes reports 415 million diabetics in the world, a number that has surpassed in half the expected time the twenty year projection. Type 2 diabetes is the most frequent form of the disease; it is characterized by a defect in
[...] Read more.
The Atlas of Diabetes reports 415 million diabetics in the world, a number that has surpassed in half the expected time the twenty year projection. Type 2 diabetes is the most frequent form of the disease; it is characterized by a defect in the secretion of insulin and a resistance in its target organs. In the search for new antidiabetic drugs, one of the principal strategies consists in promoting the action of insulin. In this sense, attention has been centered in the protein tyrosine phosphatase 1B (PTP1B), a protein whose overexpression or increase of its activity has been related in many studies with insulin resistance. In the present work, a chemical library of 250 compounds was evaluated to determine their inhibition capability on the protein PTP1B. Ten molecules inhibited over the 50% of the activity of the PTP1B, the three most potent molecules were selected for its characterization, reporting Ki values of 5.2, 4.2 and 41.3 µM, for compounds 1, 2, and 3, respectively. Docking and molecular dynamics studies revealed that the three inhibitors made interactions with residues at the secondary binding site to phosphate, exclusive for PTP1B. The data reported here support these compounds as hits for the design more potent and selective inhibitors against PTP1B in the search of new antidiabetic treatment. Full article
(This article belongs to the Special Issue Protein-Tyrosine Phosphatase Inhibitors)
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Open AccessArticle Optimization Technology of the LHS-1 Strain for Degrading Gallnut Water Extract and Appraisal of Benzene Ring Derivatives from Fermented Gallnut Water Extract Pyrolysis by Py-GC/MS
Molecules 2017, 22(12), 2253; https://doi.org/10.3390/molecules22122253
Received: 31 October 2017 / Revised: 9 December 2017 / Accepted: 11 December 2017 / Published: 20 December 2017
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Abstract
Gallnut water extract (GWE) enriches 80~90% of gallnut tannic acid (TA). In order to study the biodegradation of GWE into gallic acid (GA), the LHS-1 strain, a variant of Aspergillus niger, was chosen to determine the optimal degradation parameters for maximum production
[...] Read more.
Gallnut water extract (GWE) enriches 80~90% of gallnut tannic acid (TA). In order to study the biodegradation of GWE into gallic acid (GA), the LHS-1 strain, a variant of Aspergillus niger, was chosen to determine the optimal degradation parameters for maximum production of GA by the response surface method. Pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) was first applied to appraise benzene ring derivatives of fermented GWE (FGWE) pyrolysis by comparison with the pyrolytic products of a tannic acid standard sample (TAS) and GWE. The results showed that optimum conditions were at 31 °C and pH of 5, with a 50-h incubation period and 0.1 g·L−1 of TA as substrate. The maximum yields of GA and tannase were 63~65 mg·mL−1 and 1.17 U·mL−1, respectively. Over 20 kinds of compounds were identified as linear hydrocarbons and benzene ring derivatives based on GA and glucose. The key benzene ring derivatives were 3,4,5-trimethoxybenzoic acid methyl ester, 3-methoxy-1,2-benzenediol, and 4-hydroxy-3,5-dimethoxy-benzoic acid hydrazide. Full article
(This article belongs to the Section Chemical Biology)
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Open AccessArticle Calli Essential Oils Synergize with Lawsone against Multidrug Resistant Pathogens
Molecules 2017, 22(12), 2223; https://doi.org/10.3390/molecules22122223
Received: 30 October 2017 / Revised: 9 December 2017 / Accepted: 12 December 2017 / Published: 20 December 2017
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Abstract
The fast development of multi-drug resistant (MDR) organisms increasingly threatens global health and well-being. Plant natural products have been known for centuries as alternative medicines that can possess pharmacological characteristics, including antimicrobial activities. The antimicrobial activities of essential oil (Calli oil) extracted from
[...] Read more.
The fast development of multi-drug resistant (MDR) organisms increasingly threatens global health and well-being. Plant natural products have been known for centuries as alternative medicines that can possess pharmacological characteristics, including antimicrobial activities. The antimicrobial activities of essential oil (Calli oil) extracted from the Calligonum comosum plant by hydro-steam distillation was tested either alone or when combined with lawsone, a henna plant naphthoquinone, against MDR microbes. Lawsone showed significant antimicrobial activities against MDR pathogens in the range of 200–300 µg/mL. Furthermore, Calli oil showed significant antimicrobial activities against MDR bacteria in the range of 180–200 µg/mL, Candida at 220–240 µg/mL and spore-forming Rhizopus fungus at 250 µg/mL. Calli oil’s inhibition effect on Rhizopus, the major cause of the lethal infection mucormycosis, stands for 72 h, followed by an extended irreversible white sporulation effect. The combination of Calli oil with lawsone enhanced the antimicrobial activities of each individual alone by at least three-fold, while incorporation of both natural products in a liposome reduced their toxicity by four- to eight-fold, while maintaining the augmented efficacy of the combination treatment. We map the antimicrobial activity of Calli oil to its major component, a benzaldehyde derivative. The findings from this study demonstrate that formulations containing essential oils have the potential in the future to overcome antimicrobial resistance. Full article
(This article belongs to the Special Issue Essential Oils as Antimicrobial and Anti-infectious Agents)
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Open AccessArticle A Chemical Genetics Strategy That Identifies Small Molecules Which Induce the Triple Response in Arabidopsis
Molecules 2017, 22(12), 2270; https://doi.org/10.3390/molecules22122270
Received: 22 October 2017 / Revised: 10 December 2017 / Accepted: 13 December 2017 / Published: 19 December 2017
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Abstract
To explore small molecules with ethylene-like biological activity, we conducted a triple response-based assay system for chemical library screening. Among 9600 compounds, we found N-[(1,3,5-trimethyl-1H-pyrazol-4-yl)methyl]-N-methyl-2-naphthalenesulfonamide (EH-1) displayed promising biological activity on inducing a triple response in
[...] Read more.
To explore small molecules with ethylene-like biological activity, we conducted a triple response-based assay system for chemical library screening. Among 9600 compounds, we found N-[(1,3,5-trimethyl-1H-pyrazol-4-yl)methyl]-N-methyl-2-naphthalenesulfonamide (EH-1) displayed promising biological activity on inducing a triple response in Arabidopsis seedlings. Chemical synthesis and structure–activity relationship (SAR) analysis of EH-1 analogues with different substitution patterns on the phenyl ring structure of the sulfonamide group indicated that 3,4-dichloro-N-methyl-N-(1,3,5-trimethyl-1H-pyrazol-4-yl-methyl)benzenesulfonamide (8) exhibits the most potent biological activity. To determine the mechanism of action, we conducted RNA sequencing (RNA-Seq) analysis of the effect of EH-1 and 1-aminocyclopropane-1-carboxylate (ACC), the precursor of ethylene biosynthesis, following the quantitative real-time polymerase chain reaction (RT-PCR) confirmation. Data obtained from RNA-Seq analysis indicated that EH-1 and ACC significantly induced the expression of 39 and 48 genes, respectively (above 20 fold of control), among which five genes are up-regulated by EH-1 as well as by ACC. We also found 67 and 32 genes that are significantly down-regulated, respectively, among which seven genes are in common. For quantitative RT-PCR analysis. 12 up-regulated genes were selected from the data obtained from RNA-Seq analysis. We found a good correlation of quantitative RT-PCR analysis and RNA-Seq analysis. Based on these results, we conclude that the action mechanism of EH-1 on inducing triple response in Arabidopsis is different from that of ACC. Full article
(This article belongs to the Special Issue Sulfonamides)
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