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Molecules, Volume 19, Issue 12 (December 2014), Pages 19253-21578

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Editorial

Jump to: Research, Review

Open AccessEditorial Special Issue: Redox Active Natural Products and Their Interaction with Cellular Signalling Pathways
Molecules 2014, 19(12), 19588-19593; https://doi.org/10.3390/molecules191219588
Received: 17 November 2014 / Accepted: 18 November 2014 / Published: 26 November 2014
Cited by 2 | PDF Full-text (183 KB) | HTML Full-text | XML Full-text
Abstract
During the last decade, research into natural products has experienced a certain renaissance. The urgent need for more and more effective antibiotics in medicine, the demand for ecologically friendly plant protectants in agriculture, “natural” cosmetics and the issue of a sustainable and healthy
[...] Read more.
During the last decade, research into natural products has experienced a certain renaissance. The urgent need for more and more effective antibiotics in medicine, the demand for ecologically friendly plant protectants in agriculture, “natural” cosmetics and the issue of a sustainable and healthy nutrition in an ageing society have fuelled research into Nature’s treasure chest of “green gold”. Here, redox active secondary metabolites from plants, fungi, bacteria and other (micro-)organisms often have been at the forefront of the most interesting developments. These agents provide powerful means to interfere with many, probably most cellular signaling pathways in humans, animals and lower organisms, and therefore can be used to protect, i.e., in form of antioxidants, and to frighten off or even kill, i.e., in form of repellants, antibiotics, fungicides and selective, often catalytic “sensor/effector” anticancer agents. Interestingly, whilst natural product research dates back many decades, in some cases even centuries, and compounds such as allicin and various flavonoids have been investigated thoroughly in the past, it has only recently become possible to investigate their precise interactions and mode(s) of action inside living cells. Here, fluorescent staining and labelling on the one side, and appropriate detection, either qualitatively under the microscope or quantitatively in flow cytometers and plate readers, on the other, enable researchers to obtain the various pieces of information necessary to construct a fairly complete puzzle of how such compounds act and interact in living cells. Complemented by the more traditional activity assays and Western Blots, and increasingly joined by techniques such as proteomics, chemogenetic screening and mRNA profiling, these cell based bioanalytical techniques form a powerful platform for “intracellular diagnostics”. In the case of redox active compounds, especially of Reactive Sulfur Species (RSS), such techniques have recently unraveled concepts such as the “cellular thiolstat”, yet considerably more research is required in order to gain a full understanding of why and how such compounds act—often selectively—in different organisms. Full article
Open AccessEditorial Editorial: Special Issue — Enzyme Immobilization
Molecules 2014, 19(12), 20671-20674; https://doi.org/10.3390/molecules191220671
Received: 5 December 2014 / Accepted: 8 December 2014 / Published: 10 December 2014
Cited by 3 | PDF Full-text (645 KB) | HTML Full-text | XML Full-text
Abstract
Immobilization of enzymes and proteins is a requirement for many industrial enzyme applications, as this facilitates enzyme recovery and reuse. Bearing in mind this necessity, the coupling of immobilization to the improvement of other enzyme features has been pursued by many researchers, and
[...] Read more.
Immobilization of enzymes and proteins is a requirement for many industrial enzyme applications, as this facilitates enzyme recovery and reuse. Bearing in mind this necessity, the coupling of immobilization to the improvement of other enzyme features has been pursued by many researchers, and nowadays immobilization is recognized as a tool to improve not only stability, but also enzyme selectivity, specificity, resistance to inhibition or chemical modifiers, etc. To achieve these overall improvements of enzymes’ properties via immobilization, it is necessary to both develop new immobilization systems suitable for these purposes, and to achieve a deeper knowledge of the mechanisms of interaction between enzymes and activated solids. That way, immobilization of enzymes, far being an old-fashioned methodology to just reuse these expensive biocatalysts, is a tool of continuous interest that requires a continuous effort to be exploited in all its potential. This special issue collects 23 papers reporting advances in the field of immobilization of enzymes.[...] Full article
(This article belongs to the Special Issue Enzyme Immobilization)

Research

Jump to: Editorial, Review

Open AccessArticle K2CO3-Mediated Synthesis of Functionalised 4-Substituted-2-amino-3-cyano-4H-chromenes via Michael-Cyclization Reactions
Molecules 2014, 19(12), 19253-19268; https://doi.org/10.3390/molecules191219253
Received: 14 September 2014 / Revised: 23 October 2014 / Accepted: 5 November 2014 / Published: 25 November 2014
Cited by 7 | PDF Full-text (365 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
An efficient approach for the synthesis of functionalized 4-substituted-2-amino-3-cyano-4H-chromenes moderate to high yields (up to 98%) has been achieved via a tandem K2CO3 catalyzed conjugate addition-cyclization reaction of malononitrile and a range of Knoevenagel adducts previously formed from
[...] Read more.
An efficient approach for the synthesis of functionalized 4-substituted-2-amino-3-cyano-4H-chromenes moderate to high yields (up to 98%) has been achieved via a tandem K2CO3 catalyzed conjugate addition-cyclization reaction of malononitrile and a range of Knoevenagel adducts previously formed from oxindole, pyrazolone, nitromethane, N,N-dimethylbarbituric acid or indanedione. This methodology differs from the previous classical methods in its simplicity and ready availability of the catalyst. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Inter-Dye Distance Distributions Studied by a Combination of Single-Molecule FRET-Filtered Lifetime Measurements and a Weighted Accessible Volume (wAV) Algorithm
Molecules 2014, 19(12), 19269-19291; https://doi.org/10.3390/molecules191219269
Received: 23 August 2014 / Revised: 3 November 2014 / Accepted: 6 November 2014 / Published: 25 November 2014
Cited by 12 | PDF Full-text (1981 KB) | HTML Full-text | XML Full-text
Abstract
Förster resonance energy transfer (FRET) is an important tool for studying the structural and dynamical properties of biomolecules. The fact that both the internal dynamics of the biomolecule and the movements of the biomolecule-attached dyes can occur on similar timescales of nanoseconds is
[...] Read more.
Förster resonance energy transfer (FRET) is an important tool for studying the structural and dynamical properties of biomolecules. The fact that both the internal dynamics of the biomolecule and the movements of the biomolecule-attached dyes can occur on similar timescales of nanoseconds is an inherent problem in FRET studies. By performing single-molecule FRET-filtered lifetime measurements, we are able to characterize the amplitude of the motions of fluorescent probes attached to double-stranded DNA standards by means of flexible linkers. With respect to previously proposed experimental approaches, we improved the precision and the accuracy of the inter-dye distance distribution parameters by filtering out the donor-only population with pulsed interleaved excitation. A coarse-grained model is employed to reproduce the experimentally determined inter-dye distance distributions. This approach can easily be extended to intrinsically flexible proteins allowing, under certain conditions, to decouple the macromolecule amplitude of motions from the contribution of the dye linkers. Full article
(This article belongs to the Special Issue Single Molecule Techniques)
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Open AccessArticle Optimization of Supercritical Fluid Extraction of Oil from the Fruit of Gardenia jasminoides and Its Antidepressant Activity
Molecules 2014, 19(12), 19350-19360; https://doi.org/10.3390/molecules191219350
Received: 29 September 2014 / Revised: 6 November 2014 / Accepted: 13 November 2014 / Published: 25 November 2014
Cited by 12 | PDF Full-text (859 KB) | HTML Full-text | XML Full-text
Abstract
A response surface methodology was applied to optimize the variables affecting the supercritical fluid carbon dioxide extraction of oil from the fruit of Gardenia jasminoides using the Box–Behnken design. The optimum extraction parameters were an extraction temperature of 49.94 °C, an extraction pressure
[...] Read more.
A response surface methodology was applied to optimize the variables affecting the supercritical fluid carbon dioxide extraction of oil from the fruit of Gardenia jasminoides using the Box–Behnken design. The optimum extraction parameters were an extraction temperature of 49.94 °C, an extraction pressure of 29.89 MPa and an extraction time of 93.82 min. Through a GC/MS analysis, we revealed 16 major components of the oil extract, which showed potent antidepressant effects in both of two behavior despair models in mice: tail suspension test and forced swimming test. Our results suggest that the oil extract of Gardenia jasminoides prepared using the supercritical fluid carbon dioxide extraction may contain effective constituents to be used for depression therapy. Full article
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Open AccessArticle EOP, a Newly Synthesized Ethyl Pyruvate Derivative, Attenuates the Production of Inflammatory Mediators via p38, ERK and NF-κB Pathways in Lipopolysaccharide-Activated BV-2 Microglial Cells
Molecules 2014, 19(12), 19361-19375; https://doi.org/10.3390/molecules191219361
Received: 10 October 2014 / Revised: 3 November 2014 / Accepted: 18 November 2014 / Published: 25 November 2014
Cited by 5 | PDF Full-text (1296 KB) | HTML Full-text | XML Full-text
Abstract
Microglia-induced neuroinflammation is an important pathological mechanism influencing various neurodegenerative disorders. Excess activation of microglia produces a myriad of proinflammatory mediators that decimate neurons. Hence, therapeutic strategies aimed to suppress the activation of microglia might lead to advancements in the treatment of neurodegenerative
[...] Read more.
Microglia-induced neuroinflammation is an important pathological mechanism influencing various neurodegenerative disorders. Excess activation of microglia produces a myriad of proinflammatory mediators that decimate neurons. Hence, therapeutic strategies aimed to suppress the activation of microglia might lead to advancements in the treatment of neurodegenerative diseases. In this study, we synthesized a novel ethyl pyruvate derivative, named EOP (S-ethyl 2-oxopropanethioate) and studied its effects on lipopolysaccharide (LPS)-induced production of nitric oxide (NO) in rat primary microglia and mouse BV-2 microglia. EOP significantly decreased the production of NO, inducible nitric oxide synthase, cyclooxygenase and other proinflammatory cytokines, such as interleukin (IL)-6, IL-1β and tumor necrosis factor-α, in LPS-stimulated BV-2 microglia. The phosphorylation levels of extracellular regulated kinase, p38 mitogen-activated protein kinase, and nuclear translocation of NF-κB were also inhibited by EOP in LPS-activated BV-2 microglial cells. Overall, our observations indicate that EOP might be a promising therapeutic agent to diminish the development of neurodegenerative diseases associated with microglia activation. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Enzymatic Cellulose Hydrolysis: Enzyme Reusability and Visualization of β-Glucosidase Immobilized in Calcium Alginate
Molecules 2014, 19(12), 19390-19406; https://doi.org/10.3390/molecules191219390
Received: 31 July 2014 / Revised: 15 November 2014 / Accepted: 17 November 2014 / Published: 25 November 2014
Cited by 16 | PDF Full-text (2491 KB) | HTML Full-text | XML Full-text
Abstract
The high cellulase enzyme dosages required for hydrolysis of cellulose is a major cost challenge in lignocellulosic ethanol production. One method to decrease the enzyme dosage and increase biocatalytic productivity is to re-use β-glucosidase (BG) via immobilization. In the present research, glutaraldehyde cross-linked
[...] Read more.
The high cellulase enzyme dosages required for hydrolysis of cellulose is a major cost challenge in lignocellulosic ethanol production. One method to decrease the enzyme dosage and increase biocatalytic productivity is to re-use β-glucosidase (BG) via immobilization. In the present research, glutaraldehyde cross-linked BG was entrapped in calcium alginate gel particles. More than 60% of the enzyme activity could be recovered under optimized conditions, and glutaraldehyde cross-linking decreased leakage of BG from the calcium alginate particles. The immobilized BG aggregates were visualized by confocal laser scanning microscopy (CLSM). The CLSM images, which we believe are the first to be published, corroborate that more BG aggregates were entrapped in the matrix when the enzymes were cross-linked by glutaraldehyde as opposed to when they are not cross-linked. The particles with the immobilized BG were recycled for cellulase catalyzed hydrolysis of Avicel. No significant loss in BG activity was observed for up to 20 rounds of reaction recycle steps of the BG particles of 48 h each, verifying a significant stabilization of the BG by immobilization. Similar high glucose yields were obtained by one round of enzymatic hydrolysis of hydrothermally pretreated barley straw during a 72 h reaction with immobilized BG and free BG. Full article
(This article belongs to the Special Issue Enzyme Immobilization)
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Open AccessArticle Synthesis, Anticancer and Antibacterial Activity of Salinomycin N-Benzyl Amides
Molecules 2014, 19(12), 19435-19459; https://doi.org/10.3390/molecules191219435
Received: 14 October 2014 / Revised: 13 November 2014 / Accepted: 14 November 2014 / Published: 25 November 2014
Cited by 15 | PDF Full-text (3452 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A series of 12 novel monosubstituted N-benzyl amides of salinomycin (SAL) was synthesized for the first time and characterized by NMR and FT-IR spectroscopic methods. Molecular structures of three salinomycin derivatives in the solid state were determined using single crystal
[...] Read more.
A series of 12 novel monosubstituted N-benzyl amides of salinomycin (SAL) was synthesized for the first time and characterized by NMR and FT-IR spectroscopic methods. Molecular structures of three salinomycin derivatives in the solid state were determined using single crystal X-ray method. All compounds obtained were screened for their antiproliferative activity against various human cancer cell lines as well as against the most problematic bacteria strains such as methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE), and Mycobacterium tuberculosis. Novel salinomycin derivatives exhibited potent anticancer activity against drug-resistant cell lines. Additionally, two N-benzyl amides of salinomycin revealed interesting antibacterial activity. The most active were N-benzyl amides of SAL substituted at -ortho position and the least anticancer active derivatives were those substituted at the -para position. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessCommunication Polylactide Conjugates of Camptothecin with Different Drug Release Abilities
Molecules 2014, 19(12), 19460-19470; https://doi.org/10.3390/molecules191219460
Received: 6 October 2014 / Revised: 14 November 2014 / Accepted: 18 November 2014 / Published: 25 November 2014
Cited by 13 | PDF Full-text (494 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Camptothecin-polylactide conjugates (CMPT-PLA) were synthesized by covalent incorporation of CMPT into PLA of different microstructure, i.e., atactic PLA and atactic-block-isotactically enriched PLA (Pm = 0.79) via urethane bonds. The kinetic release of CPMT from CMPT-PLA conjugates, tested in
[...] Read more.
Camptothecin-polylactide conjugates (CMPT-PLA) were synthesized by covalent incorporation of CMPT into PLA of different microstructure, i.e., atactic PLA and atactic-block-isotactically enriched PLA (Pm = 0.79) via urethane bonds. The kinetic release of CPMT from CMPT-PLA conjugates, tested in vitro under different conditions, is possible in both cases and notably, strongly dependent on PLA microstructure. It shows that release properties of drug-PLA conjugates can be tailored by controlled design of the PLA microstructure, and allow in the case of CMPT-PLA conjugates for the development of highly controlled biodegradable CMPT systems—important delivery systems for anti-cancer agents. Full article
(This article belongs to the Special Issue Prodrugs)
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Open AccessArticle Development of an Ionic Liquid-Based Microwave-Assisted Method for the Extraction and Determination of Taxifolin in Different Parts of Larix gmelinii
Molecules 2014, 19(12), 19471-19490; https://doi.org/10.3390/molecules191219471
Received: 18 October 2014 / Revised: 16 November 2014 / Accepted: 18 November 2014 / Published: 25 November 2014
Cited by 7 | PDF Full-text (2819 KB) | HTML Full-text | XML Full-text
Abstract
An ionic liquid-based microwave-assisted extraction method (ILMAE) was successfully applied for the extraction of taxifolin from Larix gmelinii. Different kinds of 1-alkyl-3-methylimidazolium ionic liquids with different kinds of cations and anions were studied and 1-butyl-3-methylimidazolium bromide was chosen as the optimal solvent
[...] Read more.
An ionic liquid-based microwave-assisted extraction method (ILMAE) was successfully applied for the extraction of taxifolin from Larix gmelinii. Different kinds of 1-alkyl-3-methylimidazolium ionic liquids with different kinds of cations and anions were studied and 1-butyl-3-methylimidazolium bromide was chosen as the optimal solvent for taxifolin extraction. The optimal conditions of ILMAE were determined by single factor experiments and Box-Behnken design as follows: [C4mim]Br concentration of 1.00 M, soaking time of 2 h, liquid-solid ratio of 15:1 mL/g, microwave irradiation power of 406 W, microwave irradiation time of 14 min. No degradation of taxifolin had been observed under the optimum conditions as evidenced from the stability studies performed with standard taxifolin. Compared with traditional solvent and methods, ILMAE provided higher extraction yield, lower energy and time consumption. The distribution of taxifolin in different parts of larch and the influences of age, orientation, and season on the accumulation of taxifolin were analyzed for the sufficient utilization of L. gmelinii. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Synthesis of Chiral Chalcone Derivatives Catalyzed by the Chiral Cinchona Alkaloid Squaramide
Molecules 2014, 19(12), 19491-19500; https://doi.org/10.3390/molecules191219491
Received: 3 November 2014 / Revised: 13 November 2014 / Accepted: 13 November 2014 / Published: 25 November 2014
Cited by 3 | PDF Full-text (267 KB) | HTML Full-text | XML Full-text
Abstract
An effective method has been developed for the preparation of novel chiral chalcone derivatives under mild conditions from the easily accessible starting materials nitromethane and chalcone derivatives 2. The corresponding products were obtained in moderate yields with excellent enantioselectivities (up to 99%). Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Goniolactone C, a Styryl Lactone Derivative, Inhibits PDGF-BB-Induced Vascular Smooth Muscle Cell Migration and Proliferation via PDGFR/ERK Signaling
Molecules 2014, 19(12), 19501-19515; https://doi.org/10.3390/molecules191219501
Received: 21 September 2014 / Revised: 24 October 2014 / Accepted: 24 October 2014 / Published: 26 November 2014
Cited by 3 | PDF Full-text (1401 KB) | HTML Full-text | XML Full-text
Abstract
Platelet-derived growth factor-BB (PDGF-BB) and its downstream effector, extracellular signal-regulated kinase 1/2 (ERK1/2) MAP kinase, initiate a multitude of biological effects, including vascular smooth muscle cell (VSMC) proliferation and migration, which are critical events in the initiation and development of restenosis following percutaneous
[...] Read more.
Platelet-derived growth factor-BB (PDGF-BB) and its downstream effector, extracellular signal-regulated kinase 1/2 (ERK1/2) MAP kinase, initiate a multitude of biological effects, including vascular smooth muscle cell (VSMC) proliferation and migration, which are critical events in the initiation and development of restenosis following percutaneous transluminal coronary angioplasty (PTCA). Styryl lactones are natural products that have been demonstrated to possess anti-proliferative activities. Goniolactone C is a styryl lactone derivative that was first extracted from Goniothalamus cheliensis Hu. In the present study, we investigated the effects of goniolactone C on VSMC migration and proliferation. We found that goniolactone C preferentially interacted with cellular systems that rely on PDGF signaling but not those that rely on epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) signaling. Goniolactone C strongly inhibited PDGF-BB-induced VSMC migration and proliferation. goniolactone C-mediated inhibition of VSMC proliferation was associated with cell cycle arrest, while goniolactone C-mediated inhibition of VSMC migration was associated with the suppression of adhesion molecule expression. In addition, goniolactone C directly inhibited PDGFR-β kinase activity, thereby blocking the downstream effector of PDGF-BB. Thus, the results of the present study suggest a novel adjunctive pharmacological strategy that may be used to prevent angioplasty-related restenosis. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Concise and Straightforward Asymmetric Synthesis of a Cyclic Natural Hydroxy-Amino Acid
Molecules 2014, 19(12), 19516-19531; https://doi.org/10.3390/molecules191219516
Received: 7 November 2014 / Revised: 17 November 2014 / Accepted: 18 November 2014 / Published: 26 November 2014
Cited by 2 | PDF Full-text (633 KB) | HTML Full-text | XML Full-text
Abstract
An enantioselective total synthesis of the natural amino acid (2S,4R,5R)-4,5-di-hydroxy-pipecolic acid starting from D-glucoheptono-1, 4-lactone is presented. The best sequence employed as a key step the intramolecular nucleophilic displacement by an amino function of a 6-O
[...] Read more.
An enantioselective total synthesis of the natural amino acid (2S,4R,5R)-4,5-di-hydroxy-pipecolic acid starting from D-glucoheptono-1, 4-lactone is presented. The best sequence employed as a key step the intramolecular nucleophilic displacement by an amino function of a 6-O-p-toluene-sulphonyl derivative of a methyl D-arabino-hexonate and involved only 12 steps with an overall yield of 19%. The structures of the compounds synthesized were elucidated on the basis of comprehensive spectroscopic (NMR and MS) and computational analysis. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Evaluation of the Chemical and Antioxidant Properties of Wild and Cultivated Mushrooms of Ghana
Molecules 2014, 19(12), 19532-19548; https://doi.org/10.3390/molecules191219532
Received: 27 October 2014 / Revised: 12 November 2014 / Accepted: 21 November 2014 / Published: 26 November 2014
Cited by 16 | PDF Full-text (253 KB) | HTML Full-text | XML Full-text
Abstract
Knowledge of the chemical composition of both wild and cultivated edible mushrooms in Ghana is limited. This study reports their nutritional value, composition in lipophilic and hydrophilic molecules, minerals and antioxidant properties. The samples were found to be nutritionally rich in carbohydrates, ranging
[...] Read more.
Knowledge of the chemical composition of both wild and cultivated edible mushrooms in Ghana is limited. This study reports their nutritional value, composition in lipophilic and hydrophilic molecules, minerals and antioxidant properties. The samples were found to be nutritionally rich in carbohydrates, ranging from 64.14 ± 0.93 g in Pleurotus ostreatus strain EM-1 to 80.17 ± 0.34 g in Lentinus squarrosulus strain LSF. The highest level of proteins (28.40 ± 0.86 g) was recorded in the mentioned P. ostreatus strain. Low fat contents were registered in the samples, with Auricularia auricula recording the lowest value. High levels of potassium were also observed with the following decreasing order of elements: K > P ~ Na > Mg > Ca. High levels of antioxidants were also observed, thus making mushrooms suitable to be used as functional foods or nutraceutical sources. Furthermore, this study provides new information regarding chemical properties of mushrooms from Ghana, which is very important for the biodiversity characterization of this country. Full article
Open AccessArticle Resveratrol Trimers from Seed Cake of Paeonia rockii
Molecules 2014, 19(12), 19549-19556; https://doi.org/10.3390/molecules191219549
Received: 11 October 2014 / Revised: 7 November 2014 / Accepted: 18 November 2014 / Published: 26 November 2014
Cited by 6 | PDF Full-text (220 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In the course of screening natural products for antibacterial activities, a total acetone extract of the seed cake of Paeonia rockii showed significant effects against bacterial strains. Bioactivity-guided fractionation of the EtOAc-soluble fraction of the total acetone extract resulted in the isolation
[...] Read more.
In the course of screening natural products for antibacterial activities, a total acetone extract of the seed cake of Paeonia rockii showed significant effects against bacterial strains. Bioactivity-guided fractionation of the EtOAc-soluble fraction of the total acetone extract resulted in the isolation and identification of five resveratrol trimers, including rockiiol C (1), gnetin H (2), suffruticosol A (3), suffruticosol B (4) and suffruticosol C (5). The relative configuration of these compounds was elucidated mainly by comprehensive 1D and 2D-NMR experiments. Compound 1 was a new compound. All isolated compounds exhibited strong antibacterial activities against Gram-positive bacteria. Full article
(This article belongs to the Special Issue Resveratrol)
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Open AccessArticle Some Observations on the Development of Superior Photocatalytic Systems for Application to Water Purification by the “Adsorb and Shuttle” or the Interphase Charge Transfer Mechanisms
Molecules 2014, 19(12), 19557-19572; https://doi.org/10.3390/molecules191219557
Received: 21 August 2014 / Revised: 31 October 2014 / Accepted: 5 November 2014 / Published: 26 November 2014
Cited by 3 | PDF Full-text (504 KB) | HTML Full-text | XML Full-text
Abstract
Adsorb and shuttle (A/S) and interfacial charge transfer are the two major strategies for overcoming recombination in photocatalysis in this era of nanoparticle composites. Their relationships are considered here. A review of key literature is accompanied by a presentation of three new experiments
[...] Read more.
Adsorb and shuttle (A/S) and interfacial charge transfer are the two major strategies for overcoming recombination in photocatalysis in this era of nanoparticle composites. Their relationships are considered here. A review of key literature is accompanied by a presentation of three new experiments within the overall aim of assessing the relation of these strategies. The cases presented include: A/S by a high silica zeolite/TiO2 composite, charge transfer (CT) between phases in a TiO2/WO3 composite and both A/S and CT by composites of TiO2 with powered activated carbon (AC) and single-walled carbon nanotubes (SWCNT). The opportunities presented by the two strategies for moving toward photocatalysts that could support applications for the removal of contaminants from drinking water or that lead to a practical adsorbent for organics that could be regenerated photocatalytically link this discussion to ongoing research here. Full article
(This article belongs to the Special Issue Photocatalysis) Printed Edition available
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Open AccessArticle Influence of Post-Treatment Operations on Structural Properties and Photocatalytic Activity of Octahedral Anatase Titania Particles Prepared by an Ultrasonication-Hydrothermal Reaction
Molecules 2014, 19(12), 19573-19587; https://doi.org/10.3390/molecules191219573
Received: 25 September 2014 / Revised: 13 November 2014 / Accepted: 17 November 2014 / Published: 26 November 2014
Cited by 10 | PDF Full-text (2758 KB) | HTML Full-text | XML Full-text
Abstract
The influence of changes in structural and physical properties on the photocatalytic activity of octahedral anatase particles (OAPs), exposing eight equivalent {101} facets, caused by calcination (2 h) in air or grinding (1 h) in an agate mortar was studied with samples prepared
[...] Read more.
The influence of changes in structural and physical properties on the photocatalytic activity of octahedral anatase particles (OAPs), exposing eight equivalent {101} facets, caused by calcination (2 h) in air or grinding (1 h) in an agate mortar was studied with samples prepared by ultrasonication (US; 1 h)–hydrothermal reaction (HT; 24 h, 433 K). Calcination in air at temperatures up to 1173 K induced particle shape changes, evaluated by aspect ratio (AR; d001/d101 = depth vertical to anatase {001} and {101} facets estimated by the Scherrer equation with data obtained from X-ray diffraction (XRD) patterns) and content of OAP and semi-OAP particles, without transformation into rutile. AR and OAP content, as well as specific surface area (SSA), were almost unchanged by calcination at temperatures up to 673 K and were then decreased by elevating the calcination temperature, suggesting that calcination at a higher temperature caused dull-edging and particle sintering, the latter also being supported by the analysis of particle size using XRD patterns and scanning electron microscopic (SEM) images. Time-resolved microwave conductivity (TRMC) showed that the maximum signal intensity (Imax), corresponding to a product of charge-carrier density and mobility, and signal-decay rate, presumably corresponding to reactivity of charge carriers, were increased with increase in AR, suggesting higher photocatalytic activity of OAPs than that of dull-edged particles. Grinding also decreased the AR, indicating the formation of dull-edged particles. The original non-treated samples showed activities in the oxidative decomposition of acetic acid (CO2 system) and dehydrogenation of methanol (H2 system) comparable to and lower than those of a commercial anatase titania (Showa Denko Ceramics FP-6), respectively. The activities of calcined and ground samples for the CO2 system and H2 system showed almost linear relations with AR and Imax, respectively, suggesting that those activities may depend on different properties. Full article
(This article belongs to the Special Issue Photocatalysis) Printed Edition available
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Open AccessArticle The Effect of Lycii Radicis Cortex Extract on Bone Formation in Vitro and in Vivo
Molecules 2014, 19(12), 19594-19609; https://doi.org/10.3390/molecules191219594
Received: 7 October 2014 / Revised: 19 November 2014 / Accepted: 20 November 2014 / Published: 26 November 2014
Cited by 4 | PDF Full-text (1101 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Osteoporosis is a common skeletal disease caused by decreased bone mass; it enhances the risk of bone fracture. This study aimed to discover novel herbal extract(s) for the treatment of osteoporosis. We screened 64 ethanol extracts of edible plants native to Korea for
[...] Read more.
Osteoporosis is a common skeletal disease caused by decreased bone mass; it enhances the risk of bone fracture. This study aimed to discover novel herbal extract(s) for the treatment of osteoporosis. We screened 64 ethanol extracts of edible plants native to Korea for their ability to increase the cellular proliferation and differentiation of two osteoblastic cell lines: C3H10T1/2 and MC3T3-E1. We selected a Lycii Radicis Cortex (LRC), Lycium Chinese root bark as the primary candidate. Treatment with LRC extract showed enhanced alkaline phosphatase activity and increased expression of bone metabolic markers Alpl, Runx2, and Bglap genes in both osteoblastic cell lines. There was no effect on the osteoclastic differentiation of primary-cultured monocytes from the mouse bone marrows. Furthermore, the study examined the effect of LRC extract in vivo in ovariectomizd (OVX) mice for 8 weeks and 16 weeks, respectively. Bone mineral density (BMD) was significantly higher in LRC extract-administered group than in the non-LRC-administered OVX control group. The results indicated that LRC extract prevented the OVX-induced BMD loss in mice via promoting the differentiation of osteoblast linage cells. These results suggest that LRC extract may be a good natural herbal medicine candidate for the treatment of osteoporosis. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Formation of Combustible Hydrocarbons and H2 during Photocatalytic Decomposition of Various Organic Compounds under Aerated and Deaerated Conditions
Molecules 2014, 19(12), 19633-19647; https://doi.org/10.3390/molecules191219633
Received: 1 September 2014 / Revised: 4 November 2014 / Accepted: 11 November 2014 / Published: 26 November 2014
Cited by 5 | PDF Full-text (254 KB) | HTML Full-text | XML Full-text
Abstract
A possibility of photocatalytic production of useful aliphatic hydrocarbons and H2 from various organic compounds, including acetic acid, methanol, ethanol and glucose, over Fe-modified TiO2 is discussed. In particular, the influence of the reaction atmosphere (N2, air) was investigated.
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A possibility of photocatalytic production of useful aliphatic hydrocarbons and H2 from various organic compounds, including acetic acid, methanol, ethanol and glucose, over Fe-modified TiO2 is discussed. In particular, the influence of the reaction atmosphere (N2, air) was investigated. Different gases were identified in the headspace volume of the reactor depending on the substrate. In general, the evolution of the gases was more effective in air compared to a N2 atmosphere. In the presence of air, the gaseous phase contained CO2, CH4 and H2, regardless of the substrate used. Moreover, formation of C2H6 and C3H8 in the case of acetic acid and C2H6 in the case of ethanol was observed. In case of acetic acid and methanol an increase in H2 evolution under aerated conditions was observed. It was concluded that the photocatalytic decomposition of organic compounds with simultaneous generation of combustible hydrocarbons and hydrogen could be a promising method of “green energy” production. Full article
(This article belongs to the Special Issue Photocatalysis) Printed Edition available
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Open AccessArticle Microwave-Assisted Synthesis of Novel 2H-Chromene Derivatives Bearing Phenylthiazolidinones and Their Biological Activity Assessment
Molecules 2014, 19(12), 19648-19664; https://doi.org/10.3390/molecules191219648
Received: 29 September 2014 / Revised: 17 November 2014 / Accepted: 18 November 2014 / Published: 26 November 2014
Cited by 15 | PDF Full-text (866 KB) | HTML Full-text | XML Full-text | Correction
Abstract
6-Hydroxy-2-oxo-2H-chromene-4-carbaldehyde (2), 6-chloro-2-oxo-2H-chromene-4-carbaldehyde (3) and 6-hydrazinyl-4-methyl-2H-chromen-2-one (5) were prepared as single-pharmacophore motif key intermediates. Compounds 2, 3 and 5 were incorporated in a series of multicomponent reactions (MCRs), under microwave
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6-Hydroxy-2-oxo-2H-chromene-4-carbaldehyde (2), 6-chloro-2-oxo-2H-chromene-4-carbaldehyde (3) and 6-hydrazinyl-4-methyl-2H-chromen-2-one (5) were prepared as single-pharmacophore motif key intermediates. Compounds 2, 3 and 5 were incorporated in a series of multicomponent reactions (MCRs), under microwave assistance as well as conventional chemical synthesis processes, to afford a series of three and/or four-pharmacophoric-motif conjugates 8a,b, 11, 13, 16, 17, 19 and 20 in good yields. The newly synthesized compounds were characterized by IR, NMR, 13C-NMR, MS and elemental analyses. Finally the synthesized compounds have been screened for their biological activity whereupon they exhibited remarkable antimicrobial activity on different classes of bacteria and the fungus. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Facile Synthesis of Bis(indolyl)methanes Catalyzed by α-Chymotrypsin
Molecules 2014, 19(12), 19665-19677; https://doi.org/10.3390/molecules191219665
Received: 15 October 2014 / Revised: 20 November 2014 / Accepted: 21 November 2014 / Published: 27 November 2014
Cited by 8 | PDF Full-text (298 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A mild and efficient method catalyzed by α-chymotrypsin was developed for the synthesis of bis(indolyl)methanes through a cascade process between indole and aromatic aldehydes. In the ethanol aqueous solution, a green medium, a wide range of aromatic aldehydes could react with indole to
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A mild and efficient method catalyzed by α-chymotrypsin was developed for the synthesis of bis(indolyl)methanes through a cascade process between indole and aromatic aldehydes. In the ethanol aqueous solution, a green medium, a wide range of aromatic aldehydes could react with indole to afford the desired products with moderate to good yields (from 68% to 95%) using a little α-chymotrypsin as catalyst. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
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Open AccessArticle Mechanisms Underlying Vasorelaxation Induced in Rat Aorta by Galetin 3,6-Dimethyl Ether, a Flavonoid from Piptadenia stipulacea (Benth.) Ducke
Molecules 2014, 19(12), 19678-19695; https://doi.org/10.3390/molecules191219678
Received: 10 September 2014 / Revised: 17 November 2014 / Accepted: 17 November 2014 / Published: 27 November 2014
Cited by 6 | PDF Full-text (870 KB) | HTML Full-text | XML Full-text
Abstract
In this study, we investigated the relaxant action of galetin 3,6-dimethyl ether (FGAL) on rat aorta. The flavonoid relaxed both PMA‑ and phenylephrine (Phe)-induced contractions (pD2 = 5.36 ± 0.11 and 4.17 ± 0.10, respectively), suggesting the involvement of PKC and Phe
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In this study, we investigated the relaxant action of galetin 3,6-dimethyl ether (FGAL) on rat aorta. The flavonoid relaxed both PMA‑ and phenylephrine (Phe)-induced contractions (pD2 = 5.36 ± 0.11 and 4.17 ± 0.10, respectively), suggesting the involvement of PKC and Phe pathways or α1 adrenergic receptor blockade. FGAL inhibited and rightward shifted Phe-induced cumulative contraction‑response curves, indicating a noncompetitive antagonism of α1 adrenergic receptors. The flavonoid was more potent in relaxing 30 mM KCl- than 80 mM KCl-induced contractions (pD2 = 5.50 ± 0.22 and 4.37 ± 0.12). The vasorelaxant potency of FGAL on Phe-induced contraction was reduced in the presence of 10 mM TEA+. Furthermore, in the presence of apamin, glibenclamide, BaCl2 or 4-AP, FGAL-induced relaxation was attenuated, indicating the participation of small conductance calcium-activated K+ channels (SKCa), ATP-sensitive K+ channels (KATP), inward rectifier K+ channels (Kir) and voltage-dependent K+ channels (KV), respectively. FGAL inhibited and rightward shifted CaCl2-induced cumulative contraction-response curves in both depolarizing medium (high K+) and in the presence of verapamil and phenylephrine, suggesting inhibition of Ca2+ influx through voltage-gated calcium channels (CaV) and receptor operated channels (ROCs), respectively. Likewise, FGAL inhibited Phe-induced contractions in Ca2+-free medium, indicating inhibition of Ca2+ release from the sarcoplasmic reticulum (SR). FGAL potentiated the relaxant effect of aminophylline and sildenafil but not milrinone, suggesting the involvement of phosphodiesterase V (PDE V). Thus, the FGAL vasorelaxant mechanism involves noncompetitive antagonism of α1 adrenergic receptors, the non-selective opening of K+ channels, inhibition of Ca2+ influx through CaV or ROCs and the inhibition of intracellular Ca2+ release. Additionally, there is the involvement of cyclic nucleotide pathway, particularly through PDE V inhibition. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle Cloning and Characterisation of the Gene Encoding 3-Hydroxy-3-Methylglutaryl-CoA Synthase in Tripterygium wilfordii
Molecules 2014, 19(12), 19696-19707; https://doi.org/10.3390/molecules191219696
Received: 27 October 2014 / Revised: 19 November 2014 / Accepted: 20 November 2014 / Published: 27 November 2014
Cited by 11 | PDF Full-text (1157 KB) | HTML Full-text | XML Full-text
Abstract
Tripterygium wilfordii is a traditional Chinese medical plant used to treat rheumatoid arthritis and cancer. The main bioactive compounds of the plant are diterpenoids and triterpenoids. 3-Hydroxy-3-methylglutaryl-CoA synthase (HMGS) catalyses the reaction of acetoacetyl-CoA to 3-hydroxy-3-methylglutaryl-CoA, which is the first committed enzyme in
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Tripterygium wilfordii is a traditional Chinese medical plant used to treat rheumatoid arthritis and cancer. The main bioactive compounds of the plant are diterpenoids and triterpenoids. 3-Hydroxy-3-methylglutaryl-CoA synthase (HMGS) catalyses the reaction of acetoacetyl-CoA to 3-hydroxy-3-methylglutaryl-CoA, which is the first committed enzyme in the mevalonate (MVA) pathway. The sequence information of HMGS in Tripterygium wilfordii is a basic resource necessary for studying the terpenoids in the plant. In this paper, full-length cDNA encoding HMGS was isolated from Tripterygium wilfordii (abbreviated TwHMGS, GenBank accession number: KM978213). The full length of TwHMGS is 1814 bp, and the gene encodes a protein with 465 amino acids. Sequence comparison revealed that TwHMGS exhibits high similarity to HMGSs of other plants. The tissue expression patterns revealed that the expression level of TwHMGS is highest in the stems and lowest in the roots. Induced expression of TwHMGS can be induced by MeJA, and the expression level is highest 4 h after induction. The functional complement assays in the YML126C knockout yeast demonstrated that TwHMGS participates in yeast terpenoid biosynthesis. Full article
(This article belongs to the Section Molecular Diversity)
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Open AccessArticle Unstable Simple Volatiles and Gas Chromatography-Tandem Mass Spectrometry Analysis of Essential Oil from the Roots Bark of Oplopanax Horridus Extracted by Supercritical Fluid Extraction
Molecules 2014, 19(12), 19708-19717; https://doi.org/10.3390/molecules191219708
Received: 4 November 2014 / Revised: 21 November 2014 / Accepted: 24 November 2014 / Published: 27 November 2014
Cited by 2 | PDF Full-text (276 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Volatile oil from the root bark of Oplopanax horridus is regarded to be responsible for the clinical uses of the title plant as a respiratory stimulant and expectorant. Therefore, a supercritical fluid extraction method was first employed to extract the volatile oil from
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Volatile oil from the root bark of Oplopanax horridus is regarded to be responsible for the clinical uses of the title plant as a respiratory stimulant and expectorant. Therefore, a supercritical fluid extraction method was first employed to extract the volatile oil from the roots bark of O. horridus, which was subsequently analyzed by GC/MS. Forty-eight volatile compounds were identified by GC/MS analysis, including (S,E)-nerolidol (52.5%), τ-cadinol (21.6%) and S-falcarinol (3.6%). Accordingly, the volatile oil (100 g) was subjected to chromatographic separation and purification. As a result, the three compounds, (E)-nerolidol (2 g), τ-cadinol (62 mg) and S-falcarinol (21 mg), were isolated and purified from the volatile oil, the structures of which were unambiguously elucidated by detailed spectroscopic analysis including 1D- and 2D-NMR techniques. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Synthesis and Biological Evaluation of Novel 10-Substituted-7-ethyl-10-hydroxycamptothecin (SN-38) Prodrugs
Molecules 2014, 19(12), 19718-19731; https://doi.org/10.3390/molecules191219718
Received: 29 October 2014 / Revised: 19 November 2014 / Accepted: 19 November 2014 / Published: 27 November 2014
Cited by 2 | PDF Full-text (607 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In an attempt to improve the antitumor activity and reduce the side effects of irinotecan (2), novel prodrugs of SN-38 (3) were prepared by conjugating amino acids or dipeptides to the 10-hydroxyl group of SN-38 via a carbamate linkage.
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In an attempt to improve the antitumor activity and reduce the side effects of irinotecan (2), novel prodrugs of SN-38 (3) were prepared by conjugating amino acids or dipeptides to the 10-hydroxyl group of SN-38 via a carbamate linkage. The synthesized compounds completely generated SN-38 in pH 7.4 buffer or in human plasma, while remaining stable under acidic conditions. All prodrug compounds demonstrated much greater in vitro antitumor activities against HeLa cells and SGC-7901 cells than irinotecan. The most active compounds, 5h, 7c, 7d, and 7f, exhibited IC50 values that were 1000 times lower against HeLa cells and 30 times lower against SGC-7901 cells than those of irinotecan, and the inhibitory activities of these prodrugs against acetylcholinesterase (AchE) were significantly reduced, with IC50 values more than 6.8 times greater than that of irinotecan. In addition, compound 5e exhibited the same level of tumor growth inhibitory activity as irinotecan (CPT-11) in a human colon xenograft model in vivo. Full article
(This article belongs to the Special Issue Prodrugs)
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Open AccessArticle Photocatalysis for Renewable Energy Production Using PhotoFuelCells
Molecules 2014, 19(12), 19732-19750; https://doi.org/10.3390/molecules191219732
Received: 6 October 2014 / Revised: 14 November 2014 / Accepted: 24 November 2014 / Published: 27 November 2014
Cited by 20 | PDF Full-text (1255 KB) | HTML Full-text | XML Full-text
Abstract
The present work is a short review of our recent studies on PhotoFuelCells, that is, photoelectrochemical cells which consume a fuel to produce electricity or hydrogen, and presents some unpublished data concerning both electricity and hydrogen production. PhotoFuelCells have been constructed using nanoparticulate
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The present work is a short review of our recent studies on PhotoFuelCells, that is, photoelectrochemical cells which consume a fuel to produce electricity or hydrogen, and presents some unpublished data concerning both electricity and hydrogen production. PhotoFuelCells have been constructed using nanoparticulate titania photoanodes and various cathode electrodes bearing a few different types of electrocatalyst. In the case where the cell functioned with an aerated cathode, the cathode electrode was made of carbon cloth carrying a carbon paste made of carbon black and dispersed Pt nanoparticles. When the cell was operated in the absence of oxygen, the electrocatalyst was deposited on an FTO slide using a special commercial carbon paste, which was again enriched with Pt nanoparticles. Mixing of Pt with carbon paste decreased the quantity of Pt necessary to act as electrocatalyst. PhotoFuelCells can produce electricity without bias and with relatively high open-circuit voltage when they function in the presence of fuel and with an aerated cathode. In that case, titania can be sensitized in the visible region by CdS quantum dots. In the present work, CdS was deposited by the SILAR method. Other metal chalcogenides are not functional as sensitizers because the combined photoanode in their presence does not have enough oxidative power to oxidize the fuel. Concerning hydrogen production, it was found that it is difficult to produce hydrogen in an alkaline environment even under bias, however, this is still possible if losses are minimized. One way to limit losses is to short-circuit anode and cathode electrode and put them close together. This is achieved in the “photoelectrocatalytic leaf”, which was presently demonstrated capable of producing hydrogen even in a strongly alkaline environment. Full article
(This article belongs to the Special Issue Photocatalysis) Printed Edition available
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Open AccessArticle Post-Polymerization Modification of Poly(L-glutamic acid) with D-(+)-Glucosamine
Molecules 2014, 19(12), 19751-19768; https://doi.org/10.3390/molecules191219751
Received: 30 October 2014 / Revised: 20 November 2014 / Accepted: 24 November 2014 / Published: 27 November 2014
Cited by 7 | PDF Full-text (2918 KB) | HTML Full-text | XML Full-text
Abstract
Carboxyl functional groups of poly(L-glutamic acid) (PGlu) were modified with a D-(+)-glucosamine (GlcN) by amidation using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling reagent. The coupling reaction was performed in aqueous medium without protection of hydroxyl functional groups of D-(+)-glucosamine. Poly(L-glutamic acid) and GlcN
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Carboxyl functional groups of poly(L-glutamic acid) (PGlu) were modified with a D-(+)-glucosamine (GlcN) by amidation using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling reagent. The coupling reaction was performed in aqueous medium without protection of hydroxyl functional groups of D-(+)-glucosamine. Poly(L-glutamic acid) and GlcN functionalized polyglutamates (P(Glu-GlcN)) were thoroughly characterized by 1D and 2D NMR spectroscopy and SEC-MALS to gain detailed information on their structure, composition and molar mass characteristics. The results reveal successful functionalization with GlcN through the amide bond and also to a minor extent through ester bond formation in position 1 of GlcN. In addition, a ratio between the α- and β-form of glucosamine substituent coupled to polyglutamate repeating units as well as the content of residual dimethoxy triazinyl active ester moiety in the samples were evaluated. Full article
(This article belongs to the Special Issue Ring-Opening Polymerization)
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Open AccessArticle Novel Polyprenylated Phloroglucinols from Hypericum sampsonii
Molecules 2014, 19(12), 19836-19844; https://doi.org/10.3390/molecules191219836
Received: 8 October 2014 / Revised: 25 November 2014 / Accepted: 25 November 2014 / Published: 28 November 2014
Cited by 1 | PDF Full-text (260 KB) | HTML Full-text | XML Full-text
Abstract
Hypericum sampsonii Hance (Clusiaceae) is a folk medicine used in Taiwan to treat blood stasis, relieve swelling, and as an anti-hepatitis drug. Two new polyprenylated phloroglucinol derivatives, hypersampsone R (1) and hypersampsone S (2), and a known prenylated benzophenone,
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Hypericum sampsonii Hance (Clusiaceae) is a folk medicine used in Taiwan to treat blood stasis, relieve swelling, and as an anti-hepatitis drug. Two new polyprenylated phloroglucinol derivatives, hypersampsone R (1) and hypersampsone S (2), and a known prenylated benzophenone, hyperibone K (3) were isolated from the aerial parts of H. sampsonii. Their structures were determined by extensive 1D and 2D NMR, and MS spectral analyses. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Profiling of Concanavalin A-Binding Glycoproteins in Human Hepatic Stellate Cells Activated with Transforming Growth Factor-β1
Molecules 2014, 19(12), 19845-19867; https://doi.org/10.3390/molecules191219845
Received: 27 September 2014 / Revised: 18 November 2014 / Accepted: 24 November 2014 / Published: 28 November 2014
Cited by 7 | PDF Full-text (4397 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Glycoproteins play important roles in maintaining normal cell functions depending on their glycosylations. Our previous study indicated that the abundance of glycoproteins recognized by concanavalin A (ConA) was increased in human hepatic stellate cells (HSCs) following activation by transforming growth factor-β1 (TGF-β1); however,
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Glycoproteins play important roles in maintaining normal cell functions depending on their glycosylations. Our previous study indicated that the abundance of glycoproteins recognized by concanavalin A (ConA) was increased in human hepatic stellate cells (HSCs) following activation by transforming growth factor-β1 (TGF-β1); however, little is known about the ConA-binding glycoproteins (CBGs) of HSCs. In this study, we employed a targeted glycoproteomics approach using lectin-magnetic particle conjugate-based liquid chromatography-tandem mass spectrometry to compare CBG profiles between LX-2 HSCs with and without activation by TGF-β1, with the aim of discovering novel CBGs and determining their possible roles in activated HSCs. A total of 54 and 77 proteins were identified in the quiescent and activated LX-2 cells, respectively. Of the proteins identified, 14.3% were glycoproteins and 73.3% were novel potential glycoproteins. Molecules involved in protein processing in the endoplasmic reticulum (e.g., calreticulin) and calcium signaling (e.g., 1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase β-2 [PLCB2]) were specifically identified in activated LX-2 cells. Additionally, PLCB2 expression was upregulated in the cytoplasm of the activated LX-2 cells, as well as in the hepatocytes and sinusoidal cells of liver cirrhosis tissues. In conclusion, the results of this study may aid future investigations to find new molecular mechanisms involved in HSC activation and antifibrotic therapeutic targets. Full article
(This article belongs to the collection Advances in Carbohydrate Chemistry)
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Open AccessArticle New Biscoumarin Derivatives: Synthesis, Crystal Structure, Theoretical Study and Antibacterial Activity against Staphylococcus aureus
Molecules 2014, 19(12), 19868-19879; https://doi.org/10.3390/molecules191219868
Received: 24 July 2014 / Revised: 23 October 2014 / Accepted: 29 October 2014 / Published: 28 November 2014
Cited by 11 | PDF Full-text (1998 KB) | HTML Full-text | XML Full-text
Abstract
Five novel biscoumarins 15 were synthesized and characterized. In these compounds, two classical asymmetrical intramolecular O–H···O hydrogen bonds were used to stabilize the whole structures and the HB energies were performed with the density functional theory (DFT) [B3LYP/6-31G*] method. The five
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Five novel biscoumarins 15 were synthesized and characterized. In these compounds, two classical asymmetrical intramolecular O–H···O hydrogen bonds were used to stabilize the whole structures and the HB energies were performed with the density functional theory (DFT) [B3LYP/6-31G*] method. The five compounds were evaluated for their in vitro antibacterial activities against Staphylococcus aureus (S. aureus ATCC 29213), methicillin-resistant S. aureus (MRSA XJ 75302), vancomycin-intermediate S. aureus (Mu50 ATCC 700699), and USA 300 (Los Angeles County clone, LAC) by the means of minimum inhibitory concentration and time-kill curves. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Isolation and Characterization of a Novel Lectin from the Edible Mushroom Stropharia rugosoannulata
Molecules 2014, 19(12), 19880-19891; https://doi.org/10.3390/molecules191219880
Received: 14 October 2014 / Revised: 18 November 2014 / Accepted: 24 November 2014 / Published: 28 November 2014
Cited by 10 | PDF Full-text (813 KB) | HTML Full-text | XML Full-text
Abstract
To date, only a few steroids have been isolated from the mushroom Stropharia rugosoannulata which can be cultivated. In this paper, a novel lectin (SRL) with a molecular weight of 38 kDa, and a unique IKSGVYRIVSWQGALGPEAR N-terminal sequence was isolated from S. rugosoannulata
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To date, only a few steroids have been isolated from the mushroom Stropharia rugosoannulata which can be cultivated. In this paper, a novel lectin (SRL) with a molecular weight of 38 kDa, and a unique IKSGVYRIVSWQGALGPEAR N-terminal sequence was isolated from S. rugosoannulata, which represents the first protein isolated from the mushroom. The purification methods included (NH4)2SO4 precipitation, ion exchange chromatography on CM-cellulose, Q-Sepharose, and SP-Sepharose, and gel- filtration on Superdex-75. The lectin was adsorbed on all three types of ion exchangers and was purified more than 450-fold. The lectin was stable below 70 °C (with half of the activity preserved at 80 °C), and in the presence of NaOH and HCl solutions up to a concentration of 12.5 mM and 25 mM, respectively. The hemagglutinating activity of SRL was inhibited by inulin. Cd2+ and Hg2+ ions strongly reduced the hemagglutinating activity at concentrations from 1.25 mM to 10 mM. SRL exhibited anti-proliferative activity toward both hepatoma Hep G2 cells and leukemia L1210 cells, with an IC50 of 7 μM and 19 μM, respectively. The activity of HIV-1 reverse transcriptase could also be inhibited by SRL, with an IC50 of 10 μM. Full article
(This article belongs to the Special Issue Lectins)
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Open AccessArticle Maslinic Acid Induces Mitochondrial Apoptosis and Suppresses HIF-1α Expression in A549 Lung Cancer Cells under Normoxic and Hypoxic Conditions
Molecules 2014, 19(12), 19892-19906; https://doi.org/10.3390/molecules191219892
Received: 19 October 2014 / Revised: 20 November 2014 / Accepted: 21 November 2014 / Published: 28 November 2014
Cited by 9 | PDF Full-text (610 KB) | HTML Full-text | XML Full-text
Abstract
The apoptotic effects of maslinic acid (MA) at 4, 8, 16, 32 and 64 μmol/L on human lung cancer A549 cells under normoxic and hypoxic conditions were examined. MA at 4–64 and 16–64 μmol/L lowered Bcl-2 expression under normoxic and hypoxic conditions, respectively
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The apoptotic effects of maslinic acid (MA) at 4, 8, 16, 32 and 64 μmol/L on human lung cancer A549 cells under normoxic and hypoxic conditions were examined. MA at 4–64 and 16–64 μmol/L lowered Bcl-2 expression under normoxic and hypoxic conditions, respectively (p < 0.05). This agent at 4–64 μmol/L decreased Na+-K+-ATPase activity and increased caspase-3 expression under normoxic conditions, but at 8–64 μmol/L it caused these changes under hypoxic conditions (p < 0.05). MA up-regulated caspase-8, cytochrome c and apoptosis-inducing factor expression under normoxic and hypoxic conditions at 8–64 μmol/L and 32–64 μmol/L, respectively (p < 0.05). MA down-regulated hypoxia-inducible factor (HIF)-1α, vascular endothelial growth factor (VEGF), survivin and inducible nitric oxide synthase (iNOS) expression under normoxic and hypoxic conditions at 8–64 and 16–64 μmol/L, respectively (p < 0.05). After cells were pre-treated with YC-1, an inhibitor of HIF-1α, MA failed to affect the protein expression of HIF-1α, VEGF, survivin and iNOS (p > 0.05). MA at 8-64 and 32-64 μmol/L reduced reactive oxygen species and nitric oxide levels under both conditions (p < 0.05). These findings suggest that maslinic acid, a pentacyclic triterpenic acid, exerted its cytotoxic activities toward A549 cells by mediating mitochondrial apoptosis and the HIF-1α pathway. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle The Epoxidation of Limonene over the TS-1 and Ti-SBA-15 Catalysts
Molecules 2014, 19(12), 19907-19922; https://doi.org/10.3390/molecules191219907
Received: 23 October 2014 / Revised: 19 November 2014 / Accepted: 21 November 2014 / Published: 28 November 2014
Cited by 27 | PDF Full-text (265 KB) | HTML Full-text | XML Full-text
Abstract
Limonene belongs to a group of very important intermediates used in the production of fine chemicals. This monoterpene compound can be obtained from peels of oranges or lemon which are a (biomass) waste from the orange juice industry. Thus, limonene is a renewable,
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Limonene belongs to a group of very important intermediates used in the production of fine chemicals. This monoterpene compound can be obtained from peels of oranges or lemon which are a (biomass) waste from the orange juice industry. Thus, limonene is a renewable, easy available and a relatively cheap compound. This work presents preliminary studies on the process of limonene epoxidation over zeolite type catalysts such as: TS-1 and Ti-SBA-15. In these studies methanol was used as a solvent and as an oxidizing agent a 60 wt % hydrogen peroxide solution was applied. The activity of each catalyst was investigated for four chosen temperatures (0 °C, 40 °C, 80 °C and 120 °C). The reaction time was changed from 0.5 to 24 h. For each catalyst the most beneficial conditions (the appropriate temperature and the reaction time) have been established. The obtained results were compared and the most active catalyst was chosen. These studies have also shown different possible ways of limonene transformation, not only in the direction of 1,2-epoxylimonene and its corresponding diol, but also in direction of carveol, carvone and perillyl alcohol—compounds with a lot of applications. The possible mechanisms of formation of the allylic oxidation products were proposed. Full article
(This article belongs to the Special Issue Zeolite Chemistry)
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Open AccessArticle Antibacterial and EGFR-Tyrosine Kinase Inhibitory Activities of Polyhydroxylated Xanthones from Garcinia succifolia
Molecules 2014, 19(12), 19923-19934; https://doi.org/10.3390/molecules191219923
Received: 3 October 2014 / Revised: 13 November 2014 / Accepted: 24 November 2014 / Published: 28 November 2014
Cited by 10 | PDF Full-text (255 KB) | HTML Full-text | XML Full-text
Abstract
Chemical investigation of the methanol extract of the wood of Garcinia succifolia Kurz (Clusiaceae) led to the isolation of 1,5-dihydroxyxanthone (1), 1,7-dihydroxyxanthone (2), 1,3,7-trihydroxyxanthone (3), 1,5,6-trihydroxyxanthone (4), 1,6,7-trihydroxyxanthone (5), and 1,3,6,7-tetrahydroxyxanthone (6
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Chemical investigation of the methanol extract of the wood of Garcinia succifolia Kurz (Clusiaceae) led to the isolation of 1,5-dihydroxyxanthone (1), 1,7-dihydroxyxanthone (2), 1,3,7-trihydroxyxanthone (3), 1,5,6-trihydroxyxanthone (4), 1,6,7-trihydroxyxanthone (5), and 1,3,6,7-tetrahydroxyxanthone (6). All of the isolated xanthones were evaluated for their antibacterial activity against bacterial reference strains, two Gram-positive (Staphylococcus aureus ATTC 25923, Bacillus subtillis ATCC 6633) and two Gram-negative (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853), and environmental drug-resistant isolates (S. aureus B1, Enteroccoccus faecalis W1, and E. coli G1), as well as for their epidermal growth factor receptor (EGFR) of tyrosine kinase inhibitory activity. Only 1,5,6-trihydroxy-(4), 1,6,7-trihydroxy-(5), and 1,3,6,7-tetrahydroxyxanthones (6) exhibited antibacterial activity against Gram-positive bacteria, however none was active against vancomycin-resistant E. faecalis. Additionally, 1,7-dihydroxyxanthone (2) showed synergism with oxacillin, but not with ampicillin. On the other hand, only 1,5-dihydroxyxanthone (1) and 1,7-dihydroxyxanthone (2) were found to exhibit the EGFR-tyrosine kinase inhibitory activity, with IC50 values of 90.34 and 223 nM, respectively. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle Anti-Proliferative Effects of Siegesbeckia orientalis Ethanol Extract on Human Endometrial RL-95 Cancer Cells
Molecules 2014, 19(12), 19980-19994; https://doi.org/10.3390/molecules191219980
Received: 13 September 2014 / Revised: 18 November 2014 / Accepted: 21 November 2014 / Published: 1 December 2014
Cited by 6 | PDF Full-text (1973 KB) | HTML Full-text | XML Full-text
Abstract
Endometrial cancer is a common malignancy of the female genital tract. This study demonstrates that Siegesbeckia orientalis ethanol extract (SOE) significantly inhibited the proliferation of RL95-2 human endometrial cancer cells. Treating RL95-2 cells with SOE caused cell arrest in the G2/M phase and
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Endometrial cancer is a common malignancy of the female genital tract. This study demonstrates that Siegesbeckia orientalis ethanol extract (SOE) significantly inhibited the proliferation of RL95-2 human endometrial cancer cells. Treating RL95-2 cells with SOE caused cell arrest in the G2/M phase and induced apoptosis of RL95-2 cells by up-regulating Bad, Bak and Bax protein expression and down-regulation of Bcl-2 and Bcl-xL protein expression. Treatment with SOE increased protein expression of caspase-3, -8 and -9 dose-dependently, indicating that apoptosis was through the intrinsic and extrinsic apoptotic pathways. Moreover, SOE was also effective against A549 (lung cancer), Hep G2 (hepatoma), FaDu (pharynx squamous cancer), MDA-MB-231 (breast cancer), and especially on LNCaP (prostate cancer) cell lines. In total, 10 constituents of SOE were identified by Gas chromatography-mass analysis. Caryophyllene oxide and caryophyllene are largely responsible for most cytotoxic activity of SOE against RL95-2 cells. Overall, this study suggests that SOE is a promising anticancer agent for treating endometrial cancer. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle Effects of Selected Dietary Secondary Metabolites on Reactive Oxygen Species Production Caused by Iron(II) Autoxidation
Molecules 2014, 19(12), 20023-20033; https://doi.org/10.3390/molecules191220023
Received: 11 August 2014 / Revised: 22 November 2014 / Accepted: 24 November 2014 / Published: 1 December 2014
Cited by 9 | PDF Full-text (298 KB) | HTML Full-text | XML Full-text
Abstract
Iron is an essential co-factor for many enzymes that catalyze electron transfer reactions. It is well known that so-called “poorly liganded” iron can increase ROS concentrations and trigger oxidative stress that is capable of initiating apoptosis. Conversely, controlled ROS production has been recognized
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Iron is an essential co-factor for many enzymes that catalyze electron transfer reactions. It is well known that so-called “poorly liganded” iron can increase ROS concentrations and trigger oxidative stress that is capable of initiating apoptosis. Conversely, controlled ROS production has been recognized as an integral part of cellular signaling. Elevated ROS concentrations are associated with aging, inflammatory and degenerative diseases. Anti-aging properties have been attributed especially to antioxidant phenolic plant metabolites that represent food additives in our diet. Consequently, this study explores the effects of flavonoids (quercetin and rutin), several phenolic acids (caffeic, chlorogenic, and protocatechuic acid), and the alkaloid caffeine on iron(II) autoxidation and ROS production in comparison to the standard antioxidants ascorbic acid and Trolox. The iron(II) autoxidation assay was carried out in pH 6.0 (plant apoplast and inflamed human tissue) and 7.4 (cell cytoplasm and human blood plasma). The obtained results accentuate phenolic acids as the more specific antioxidants compared to ascorbic acid and Trolox. Flavonoid redox chemistry depends more on the chemical milieu, specifically on pH. In vivo, the presence of iron cannot be ruled out and “wrongly” or “poorly” complexed iron has been pointed out as causative agent of various age-related diseases. Full article
(This article belongs to the Special Issue Natural Antioxidants and Ageing)
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Open AccessArticle Chemical Composition, Antibacterial and Antioxidant Activities of Six Essentials Oils from the Alliaceae Family
Molecules 2014, 19(12), 20034-20053; https://doi.org/10.3390/molecules191220034
Received: 20 October 2014 / Revised: 19 November 2014 / Accepted: 20 November 2014 / Published: 1 December 2014
Cited by 38 | PDF Full-text (740 KB) | HTML Full-text | XML Full-text
Abstract
Six essential oils (EOs) from the Alliaceae family, namely garlic (Allium sativum), onion (Allium cepa), leek (Allium porrum), Chinese chive (Allium tuberosum), shallot (Allium ascalonicum) and chive (Allium schoenoprasum) were characterized by GC
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Six essential oils (EOs) from the Alliaceae family, namely garlic (Allium sativum), onion (Allium cepa), leek (Allium porrum), Chinese chive (Allium tuberosum), shallot (Allium ascalonicum) and chive (Allium schoenoprasum) were characterized by GC and GC-MS and evaluated for their functional food properties. Antibacterial properties were tested on five food-borne pathogens: Two Gram-positive Staphylococcus aureus (ATCC 25923), Listeria monocytogenes (ATCC 19115) and three Gram-negative Salmonella Typhimurium (ATCC 14028), Escherichia coli (ATCC 8739) and Campylobacter jejuni (ATCC 33291) bacteria. Antioxidant and radical-scavenging properties were tested by means of Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Garlic, Chinese chive and onion EOs had the highest antibacterial activity whereas shallot and leek EOs were the strongest antioxidants. Heating caused a decrease in the antioxidant activity of these Eos, as shown in the Total Polar Materials (TPM) test. Suggestions on relationships between chemical composition and biological activities are presented. Results show that the EOs could be of value in the food industry as alternatives to synthetic antioxidants. Full article
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Open AccessArticle Resveratrol Modulates the Topoisomerase Inhibitory Potential of Doxorubicin in Human Colon Carcinoma Cells
Molecules 2014, 19(12), 20054-20072; https://doi.org/10.3390/molecules191220054
Received: 3 September 2014 / Revised: 24 November 2014 / Accepted: 25 November 2014 / Published: 1 December 2014
Cited by 8 | PDF Full-text (634 KB) | HTML Full-text | XML Full-text
Abstract
Resveratrol (RSV) is currently being widely discussed as potentially useful for anticancer therapy in combination with classical chemotherapeutics, e.g., the topoisomerase II (TOP II) poison doxorubicin (DOX). However, there is still a lack of knowledge of possible interference at the target enzyme, especially
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Resveratrol (RSV) is currently being widely discussed as potentially useful for anticancer therapy in combination with classical chemotherapeutics, e.g., the topoisomerase II (TOP II) poison doxorubicin (DOX). However, there is still a lack of knowledge of possible interference at the target enzyme, especially since RSV itself has recently been described to act as a TOP poison. We therefore sought to address the question whether RSV affects DOX-induced genotoxic and cytotoxic effects with special emphasis on TOP II in HT-29 colon carcinoma cells. RSV was found to counteract DOX-induced formation of DNA-TOP-intermediates at ≥100 µM for TOP IIα and at 250 µM for TOP IIβ. As a consequence, RSV modulated the DNA-strand breaking potential of DOX by mediating protective effects with an apparent maximum at 100 µM. At higher concentration ranges (≥200 µM) RSV diminished the intracellular concentrations of DOX. Nevertheless, the presence of RSV slightly enhanced the cytotoxic effects of DOX after 1.5 h and 24 h of incubation. Taken together, at least in cell culture RSV was found to affect the TOP-poisoning potential of DOX and to modulate its cytotoxic effectiveness. Thus, further studies are needed to clarify the impact of RSV on the therapeutic effectiveness of DOX under in vivo conditions. Full article
(This article belongs to the Special Issue Resveratrol)
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Open AccessArticle Alteration of N-glycans and Expression of Their Related Glycogenes in the Epithelial-Mesenchymal Transition of HCV29 Bladder Epithelial Cells
Molecules 2014, 19(12), 20073-20090; https://doi.org/10.3390/molecules191220073
Received: 31 October 2014 / Revised: 23 November 2014 / Accepted: 24 November 2014 / Published: 1 December 2014
Cited by 9 | PDF Full-text (2890 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The epithelial-mesenchymal transition (EMT) is an essential step in the proliferation and metastasis of solid tumor cells, and glycosylation plays a crucial role in the EMT process. Certain aberrant glycans have been reported as biomarkers during bladder cancer progression, but global variation of
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The epithelial-mesenchymal transition (EMT) is an essential step in the proliferation and metastasis of solid tumor cells, and glycosylation plays a crucial role in the EMT process. Certain aberrant glycans have been reported as biomarkers during bladder cancer progression, but global variation of N-glycans in this type of cancer has not been previously studied. We examined the profiles of N-glycan and glycogene expression in transforming growth factor-beta (TGFβ)-induced EMT using non-malignant bladder transitional epithelium HCV29 cells. These expression profiles were analyzed by mass spectrometry, lectin microarray analysis, and GlycoV4 oligonucleotide microarray analysis, and confirmed by lectin histochemistry and real-time RT-PCR. The expression of 5 N-glycan-related genes were notably altered in TGFβ-induced EMT. In particular, reduced expression of glycogene man2a1, which encodes α-mannosidase 2, contributed to the decreased proportions of bi-, tri- and tetra-antennary complex N-glycans, and increased expression of hybrid-type N-glycans. Decreased expression of fuca1 gene, which encodes Type 1 α-L-fucosidase, contributed to increased expression of fucosylated N-glycans in TGFβ-induced EMT. Taken together, these findings clearly demonstrate the involvement of aberrant N-glycan synthesis in EMT in these cells. Integrated glycomic techniques as described here will facilitate discovery of glycan markers and development of novel diagnostic and therapeutic approaches to bladder cancer. Full article
(This article belongs to the Special Issue Lectins)
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Open AccessArticle Assessment of Genetic Diversity in Seed Plants Based on a Uniform π Criterion
Molecules 2014, 19(12), 20113-20127; https://doi.org/10.3390/molecules191220113
Received: 21 April 2014 / Revised: 12 November 2014 / Accepted: 19 November 2014 / Published: 1 December 2014
Cited by 3 | PDF Full-text (513 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Despite substantial advances in genotyping techniques and massively accumulated data over the past half century, a uniform measurement of neutral genetic diversity derived by different molecular markers across a wide taxonomical range has not yet been formulated. We collected genetic diversity data on
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Despite substantial advances in genotyping techniques and massively accumulated data over the past half century, a uniform measurement of neutral genetic diversity derived by different molecular markers across a wide taxonomical range has not yet been formulated. We collected genetic diversity data on seed plants derived by AFLP, allozyme, ISSR, RAPD, SSR and nucleotide sequences, converted expected heterozygosity (He) to nucleotide diversity (π), and reassessed the relationship between plant genetic diversity and life history traits or extinction risk. We successfully established a uniform π criterion and developed a comprehensive plant genetic diversity database. The mean population-level and species-level π values across seed plants were 0.00374 (966 taxa, 155 families, 47 orders) and 0.00569 (728 taxa, 130 families, 46 orders), respectively. Significant differences were recovered for breeding system (p < 0.001) at the population level and geographic range (p = 0.023) at the species level. Selfing taxa had significantly lower π values than outcrossing and mixed-mating taxa, whereas narrowly distributed taxa had significantly lower π values than widely distributed taxa. Despite significant differences between the two extreme threat categories (critically endangered and least concern), the genetic diversity reduction on the way to extinction was difficult to detect in early stages. Full article
(This article belongs to the Section Molecular Diversity)
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Open AccessArticle Radiosensitizing Effect of Schinifoline from Zanthoxylum schinifolium Sieb et Zucc on Human Non-Small Cell Lung Cancer A549 Cells: A Preliminary in Vitro Investigation
Molecules 2014, 19(12), 20128-20138; https://doi.org/10.3390/molecules191220128
Received: 23 October 2014 / Revised: 17 November 2014 / Accepted: 26 November 2014 / Published: 1 December 2014
Cited by 3 | PDF Full-text (958 KB) | HTML Full-text | XML Full-text
Abstract
Schinifoline (SF), a 4-quinolinone derivative, was found in Zanthoxylum schinifolium for the first time. 4-Quinolinone moieties are thought to have cytotoxic activity and are often used as a tubulin polymerization inhibitors, heterogeneous enzyme inhibitors and antiplatelet agents. However, very little information respect to
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Schinifoline (SF), a 4-quinolinone derivative, was found in Zanthoxylum schinifolium for the first time. 4-Quinolinone moieties are thought to have cytotoxic activity and are often used as a tubulin polymerization inhibitors, heterogeneous enzyme inhibitors and antiplatelet agents. However, very little information respect to radiosensitization has focused on SF. This work aimed to investigate the radiosensitizing effect of SF on A549 cells. The cell viability results indicated cytotoxicity of SF on A549 cells, with IC50 values of 33.7 ± 2.4, 21.9 ± 1.9 and 16.8 ± 2.2 μg/mL, respectively, after 6, 12, 24 h treatment with different concentrations, and the 10% or 20% IC50 concentration during 12 h was applied in later experiments. The results of cell proliferative inhibition and clonogenic assay showed that SF enhanced the radiosensitivity of A549 cells when applied before 60Co γ-irradiation and this effect was mainly time and concentration dependent. The flow cytometric data indicated that SF treatment before the irradiation increased the G2/M phase, thus improving the radiosensitivity of A549, leading to cell apoptosis. This paper is the first study that describes the in vitro radiosensitising, cell cycle and apoptotic-inducing effects of schinifoline. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Aggregation Behavior of Long-Chain Piperidinium Ionic Liquids in Ethylammonium Nitrate
Molecules 2014, 19(12), 20157-20169; https://doi.org/10.3390/molecules191220157
Received: 13 October 2014 / Revised: 7 November 2014 / Accepted: 21 November 2014 / Published: 2 December 2014
Cited by 4 | PDF Full-text (1764 KB) | HTML Full-text | XML Full-text
Abstract
Micelles formed by the long-chain piperidinium ionic liquids (ILs) N-alkyl-N-methylpiperidinium bromide of general formula CnPDB (n = 12, 14, 16) in ethylammonium nitrate (EAN) were investigated through surface tension and dissipative particle dynamics (DPD) simulations. Through surface
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Micelles formed by the long-chain piperidinium ionic liquids (ILs) N-alkyl-N-methylpiperidinium bromide of general formula CnPDB (n = 12, 14, 16) in ethylammonium nitrate (EAN) were investigated through surface tension and dissipative particle dynamics (DPD) simulations. Through surface tension measurements, the critical micelle concentration (cmc), the effectiveness of surface tension reduction (Πcmc), the maximum excess surface concentration (Гmax) and the minimum area occupied per surfactant molecule (Amin) can be obtained. A series of thermodynamic parameters (DG0 m, DH0 m and DS0 m) of micellization can be calculated and the results showed that the micellization was entropy-driven. In addition, the DPD simulation was performed to simulate the whole aggregation process behavior to better reveal the micelle formation process. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Potential Mechanism of Action of meso-Dihydroguaiaretic Acid on Mycobacterium tuberculosis H37Rv
Molecules 2014, 19(12), 20170-20182; https://doi.org/10.3390/molecules191220170
Received: 19 September 2014 / Revised: 8 November 2014 / Accepted: 11 November 2014 / Published: 2 December 2014
Cited by 6 | PDF Full-text (1071 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The isolation and characterization of the lignan meso-dihydroguaiaretic acid (MDGA) from Larrea tridentata and its activity against Mycobacterial tuberculosis has been demonstrated, but no information regarding its mechanism of action has been documented. Therefore, in this study we carry out the gene
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The isolation and characterization of the lignan meso-dihydroguaiaretic acid (MDGA) from Larrea tridentata and its activity against Mycobacterial tuberculosis has been demonstrated, but no information regarding its mechanism of action has been documented. Therefore, in this study we carry out the gene expression from total RNA obtained from M. tuberculosis H37Rv treated with MDGA using microarray technology, which was validated by quantitative real time polymerase chain reaction. Results showed that the alpha subunit of coenzyme A transferase of M. tuberculosis H37Rv is present in both geraniol and 1-and 2-methylnaphthalene degradation pathways, which are targeted by MDGA. This assumption was supported by molecular docking which showed stable interaction between MDGA with the active site of the enzyme. We propose that inhibition of coenzyme A transferase of M. tuberculosis H37Rv results in the accumulation of geraniol and 1-and 2-methylnaphtalene inside bacteria, causing membrane destabilization and death of the pathogen. The natural product MDGA is thus an attractive template to develop new anti-tuberculosis drugs, because its target is different from those of known anti-tubercular agents. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle Evolution of the Aroma Volatiles of Pear Fruits Supplemented with Fatty Acid Metabolic Precursors
Molecules 2014, 19(12), 20183-20196; https://doi.org/10.3390/molecules191220183
Received: 19 September 2014 / Revised: 13 November 2014 / Accepted: 26 November 2014 / Published: 2 December 2014
Cited by 8 | PDF Full-text (284 KB) | HTML Full-text | XML Full-text
Abstract
To examine the biochemical metabolism of aroma volatiles derived from fatty acids, pear fruits were incubated in vitro with metabolic precursors of these compounds. Aroma volatiles, especially esters, were significantly increased, both qualitatively and quantitatively, in pear fruits fed on fatty acid metabolic
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To examine the biochemical metabolism of aroma volatiles derived from fatty acids, pear fruits were incubated in vitro with metabolic precursors of these compounds. Aroma volatiles, especially esters, were significantly increased, both qualitatively and quantitatively, in pear fruits fed on fatty acid metabolic precursors. Cultivars having different flavor characteristics had distinctly different aroma volatile metabolisms. More esters were formed in fruity-flavored “Nanguoli” fruits than in green-flavored “Dangshansuli” fruits fed on the same quantities of linoleic acid and linolenic acid. Hexanal and hexanol were more efficient metabolic intermediates for volatile synthesis than linoleic acid and linolenic acid. Hexyl esters were the predominant esters produced by pear fruits fed on hexanol, and their contents in “Dangshansuli” fruits were higher than in “Nanguoli” fruits. Hexyl esters and hexanoate esters were the primary esters produced in pear fruits fed on hexanal, however the content of hexyl ester in “Dangshansuli” was approximately three times that in “Nanguoli”. The higher contents of hexyl esters in “Dangshansuli” may have resulted from a higher level of hexanol derived from hexanal. In conclusion, the synthesis of aroma volatiles was largely dependent on the metabolic precursors presented. Full article
(This article belongs to the Special Issue Aromas and Volatiles of Fruits)
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Open AccessArticle Multitarget Molecular Hybrids of Cinnamic Acids
Molecules 2014, 19(12), 20197-20226; https://doi.org/10.3390/molecules191220197
Received: 27 October 2014 / Revised: 14 November 2014 / Accepted: 25 November 2014 / Published: 2 December 2014
Cited by 12 | PDF Full-text (3855 KB) | HTML Full-text | XML Full-text
Abstract
In an attempt to synthesize potential new multitarget agents, 11 novel hybrids incorporating cinnamic acids and paracetamol, 4-/7-hydroxycoumarin, benzocaine, p-aminophenol and m-aminophenol were synthesized. Three hybrids—2e, 2a, 2g—and 3b were found to be multifunctional agents. The hybrid
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In an attempt to synthesize potential new multitarget agents, 11 novel hybrids incorporating cinnamic acids and paracetamol, 4-/7-hydroxycoumarin, benzocaine, p-aminophenol and m-aminophenol were synthesized. Three hybrids—2e, 2a, 2g—and 3b were found to be multifunctional agents. The hybrid 2e derived from the phenoxyphenyl cinnamic acid and m-acetamidophenol showed the highest lipoxygenase (LOX) inhibition and analgesic activity (IC50 = 0.34 μΜ and 98.1%, whereas the hybrid 3b of bromobenzyloxycinnamic acid and hymechromone exhibited simultaneously good LOX inhibitory activity (IC50 = 50 μΜ) and the highest anti-proteolytic activity (IC50= 5 μΜ). The hybrid 2a of phenyloxyphenyl acid with paracetamol showed a high analgesic activity (91%) and appears to be a promising agent for treating peripheral nerve injuries. Hybrid 2g which has an ester and an amide bond presents an interesting combination of anti-LOX and anti-proteolytic activity. The esters were found very potent and especially those derived from paracetamol and m-acetamidophenol. The amides follow. Based on 2D-structure–activity relationships it was observed that both steric and electronic parameters play major roles in the activity of these compounds. Molecular docking studies point to the fact that allosteric interactions might govern the LOX-inhibitor binding. Full article
(This article belongs to the Special Issue Cinnamic Acids Hybrids with Biological Interest)
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Open AccessArticle Two New N-Oxide Alkaloids from Stemona cochinchinensis
Molecules 2014, 19(12), 20257-20265; https://doi.org/10.3390/molecules191220257
Received: 24 October 2014 / Revised: 27 November 2014 / Accepted: 1 December 2014 / Published: 3 December 2014
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Abstract
Two new N-oxide alkaloids with pyrrolo[1,2-α]azepine skeleton, namely isoneostemocochinine-N-oxide (1) and neostemocochinine-N-oxide (2), as well as three known alkaloids with pyrido[1,2-α]azepine skeletons, were isolated and identified from the roots of Stemona cochinchinensis (Stemonaceae). The structures of these compounds were
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Two new N-oxide alkaloids with pyrrolo[1,2-α]azepine skeleton, namely isoneostemocochinine-N-oxide (1) and neostemocochinine-N-oxide (2), as well as three known alkaloids with pyrido[1,2-α]azepine skeletons, were isolated and identified from the roots of Stemona cochinchinensis (Stemonaceae). The structures of these compounds were elucidated by 1D- and 2D-NMR spectra and other spectroscopic studies. Additionally, the 1H- and 13C-NMR characteristic of N-oxide Stemona alkaloids was summarized. Stemokerrin showed potent anti-tussive activity on citric acid-induced guinea pig model. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle The Regulation of Anthocyanin Synthesis in the Wheat Pericarp
Molecules 2014, 19(12), 20266-20279; https://doi.org/10.3390/molecules191220266
Received: 30 September 2014 / Revised: 24 November 2014 / Accepted: 27 November 2014 / Published: 4 December 2014
Cited by 21 | PDF Full-text (905 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Bread wheat producing grain in which the pericarp is purple is considered to be a useful source of dietary anthocyanins. The trait is under the control of the Pp-1 homoealleles (mapping to each of the group 7 chromosomes) and Pp3 (on chromosome 2A).
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Bread wheat producing grain in which the pericarp is purple is considered to be a useful source of dietary anthocyanins. The trait is under the control of the Pp-1 homoealleles (mapping to each of the group 7 chromosomes) and Pp3 (on chromosome 2A). Here, TaMyc1 was identified as a likely candidate for Pp3. The gene encodes a MYC-like transcription factor. In genotypes carrying the dominant Pp3 allele, TaMyc1 was strongly transcribed in the pericarp and, although at a lower level, also in the coleoptile, culm and leaf. The gene was located to chromosome 2A. Three further copies were identified, one mapping to the same chromosome arm as TaMyc1 and the other two mapping to the two other group 2 chromosomes; however none of these extra copies were transcribed in the pericarp. Analysis of the effect of the presence of combinations of Pp3 and Pp-1 genotype on the transcription behavior of TaMyc1 showed that the dominant allele Pp-D1 suppressed the transcription of TaMyc1. Full article
(This article belongs to the Special Issue Anthocyanins) Printed Edition available
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Open AccessArticle Structures of Some Novel α-Glucosyl Diterpene Glycosides from the Glycosylation of Steviol Glycosides
Molecules 2014, 19(12), 20280-20294; https://doi.org/10.3390/molecules191220280
Received: 10 October 2014 / Revised: 26 November 2014 / Accepted: 28 November 2014 / Published: 4 December 2014
Cited by 6 | PDF Full-text (741 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Four new minor diterpene glycosides with a rare α-glucosyl linkage were isolated from a cyclodextrin glycosyltransferase glucosylated stevia extract containing more than 98% steviol glycosides. The new compounds were identified as 13-[(2-O-β-D-glucopyranosyl-3-O-(4-O-α-D-glucopyranosyl)-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-α-D-glucopyranosyl-β-D-glucopyranosyl)
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Four new minor diterpene glycosides with a rare α-glucosyl linkage were isolated from a cyclodextrin glycosyltransferase glucosylated stevia extract containing more than 98% steviol glycosides. The new compounds were identified as 13-[(2-O-β-D-glucopyranosyl-3-O-(4-O-α-D-glucopyranosyl)-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-α-D-glucopyranosyl-β-D-glucopyranosyl) ester] (1), 13-[(2-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-(4-O-(4-O-α-D-glucopyranosyl)-α-D-glucopyranosyl)-α-D-glucopyranosyl)-β-D-glucopyranosyl ester] (2), 13-[(2-O-β-D-glucopyranosyl-3-O-(4-O-(4-O-(4-O-α-D-glucopyranosyl)-α-D-glucopyranosyl)-α-D-glucopyranosyl)-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid β-D-glucopyranosyl ester (3), and 13-[(2-O-β-D-glucopyranosyl-3-O-(4-O-(4-O-(4-O-α-D-glucopyranosyl)-α-D-glucopyranosyl)-α-D-glucopyranosyl)-β-D-glucopyranosyl- β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(4-O-α-D-glucopyranosyl-β-D-glucopyranosyl) ester] (4) on the basis of extensive NMR and mass spectral (MS) data as well as hydrolysis studies. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle A Novel Extended N-Methyl Monopyrrolotetrathiafulvalene Based on 2-Methylene-4,5-Bis(Methylthio)-1,3-Dithiole
Molecules 2014, 19(12), 20314-20324; https://doi.org/10.3390/molecules191220314
Received: 11 October 2014 / Revised: 21 November 2014 / Accepted: 24 November 2014 / Published: 4 December 2014
PDF Full-text (3765 KB) | HTML Full-text | XML Full-text
Abstract
The title compound was prepared via a cross-coupling reaction and its crystal structure has been determined. It crystallized in the triclinic space group P-1 with cell parameters: a = 8.552(2) Å, b = 11.310(2) Å, c = 16.150(3) Å, α = 109.55(3)°,
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The title compound was prepared via a cross-coupling reaction and its crystal structure has been determined. It crystallized in the triclinic space group P-1 with cell parameters: a = 8.552(2) Å, b = 11.310(2) Å, c = 16.150(3) Å, α = 109.55(3)°, β = 91.45(3)°, γ = 91.28(3)°, V = 1470.6(5) Å3, Z = 2 at 296 K. There is one molecule in the asymmetric unit. In the crystal structure, the neighboring molecules from dimers by weak intermolecular π···π interactions between the pyrrole and tetrathiafulvalene units. The dimers are further linked through C-H···π interactions to generate one-dimensional chains along the [100] direction. The arrangement of the molecules corresponds to an overlap between the HOMO and LUMO. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Formulation, Characterization, and in Vivo Evaluation of Celecoxib-PVP Solid Dispersion Nanoparticles Using Supercritical Antisolvent Process
Molecules 2014, 19(12), 20325-20339; https://doi.org/10.3390/molecules191220325
Received: 13 November 2014 / Revised: 1 December 2014 / Accepted: 3 December 2014 / Published: 4 December 2014
Cited by 12 | PDF Full-text (8442 KB) | HTML Full-text | XML Full-text
Abstract
The aim of this study was to develop celecoxib-polyvinylpyrrolidone (PVP) solid dispersion nanoparticles with and without surfactant using the supercritical antisolvent (SAS) process. The effect of different surfactants such as gelucire 44/14, poloxamer 188, poloxamer 407, Ryoto sugar ester L1695, and d-α-tocopheryl polyethylene
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The aim of this study was to develop celecoxib-polyvinylpyrrolidone (PVP) solid dispersion nanoparticles with and without surfactant using the supercritical antisolvent (SAS) process. The effect of different surfactants such as gelucire 44/14, poloxamer 188, poloxamer 407, Ryoto sugar ester L1695, and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) on nanoparticle formation and dissolution as well as oral absorption of celecoxib-PVP K30 solid dispersion nanoparticles was investigated. Spherical celecoxib solid dispersion nanoparticles less than 300 nm in size were successfully developed using the SAS process. Analysis by differential scanning calorimetry and powder X-ray diffraction showed that celecoxib existed in the amorphous form within the solid dispersion nanoparticles fabricated using the SAS process. The celecoxib-PVP-TPGS solid dispersion nanoparticles significantly enhanced in vitro dissolution and oral absorption of celecoxib relative to that of the unprocessed form. The area under the concentration-time curve (AUC0→24 h) and peak plasma concentration (Cmax) increased 4.6 and 5.7 times, respectively, with the celecoxib-PVP-TPGS formulation. In addition, in vitro dissolution efficiency was well correlated with in vivo pharmacokinetic parameters. The present study demonstrated that formulation of celecoxib-PVP-TPGS solid dispersion nanoparticles using the SAS process is a highly effective strategy for enhancing the bioavailability of poorly water-soluble celecoxib. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessCommunication Saikosaponin D Isolated from Bupleurum falcatum Inhibits Selectin-Mediated Cell Adhesion
Molecules 2014, 19(12), 20340-20349; https://doi.org/10.3390/molecules191220340
Received: 6 November 2014 / Revised: 2 December 2014 / Accepted: 2 December 2014 / Published: 4 December 2014
Cited by 6 | PDF Full-text (1951 KB) | HTML Full-text | XML Full-text
Abstract
Three saikosaponins were isolated from the MeOH extract of the roots of Bupleurum falcatum L.: saikosaponins B3 (1); B4 (2); and D (3). Of the three, compound 3 inhibited the interaction of selectins (E, L, and P)
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Three saikosaponins were isolated from the MeOH extract of the roots of Bupleurum falcatum L.: saikosaponins B3 (1); B4 (2); and D (3). Of the three, compound 3 inhibited the interaction of selectins (E, L, and P) and THP-1 cells with IC50 values of 1.8, 3.0 and 4.3 µM, respectively. Also, the aglycone structure 4 of compound 3 showed moderate inhibitory activity on L-selectin-mediated cell adhesion. From these results, we suspect that compound 3 isolated from Bupleurum falcatum roots would be a good candidate for therapeutic strategies to treat inflammation. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle Are Vicilins Another Major Class of Legume Lectins?
Molecules 2014, 19(12), 20350-20373; https://doi.org/10.3390/molecules191220350
Received: 21 August 2014 / Revised: 11 November 2014 / Accepted: 19 November 2014 / Published: 5 December 2014
Cited by 6 | PDF Full-text (2315 KB) | HTML Full-text | XML Full-text
Abstract
Legume lectins comprise a structurally related, Ca/Mn-dependent, widespread, abundant and well characterized lectin family when compared to the large number of lectins from other sources described in the literature. Strangely enough, no specific function has been assigned to them aside from a possible
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Legume lectins comprise a structurally related, Ca/Mn-dependent, widespread, abundant and well characterized lectin family when compared to the large number of lectins from other sources described in the literature. Strangely enough, no specific function has been assigned to them aside from a possible role in storage and/or defense. Using a recent and fine-tuned methodology capable of specific lectin identification, β-conglutin, Vicia faba vicilin and β-lathyrin, the vicilin storage globulins from Lupinus albus, V. faba and Lathyrus sativus, respectively, were shown to be capable of affinity binding to thoroughly washed erythrocyte membranes and of specific elution with appropriate sugars. Based on this evidence and on sparse data published in the literature, a second family of legume lectins is proposed: the 7S family of storage proteins from leguminous seeds, or family II of legume lectins. These lectins are also structurally related, widespread and well characterized. In addition, they self-aggregate in a Ca/Mg, electrostatic dependent manner and are even more abundant than the family I of legume lectins. Using the same evidence, reserve and defense roles may be attributed to family II of legume lectins. Full article
(This article belongs to the Special Issue Lectins)
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Open AccessArticle Antiprotozoal Activity of (E)-Cinnamic N-Acylhydrazone Derivatives
Molecules 2014, 19(12), 20374-20381; https://doi.org/10.3390/molecules191220374
Received: 28 October 2014 / Revised: 29 November 2014 / Accepted: 1 December 2014 / Published: 5 December 2014
Cited by 3 | PDF Full-text (697 KB) | HTML Full-text | XML Full-text
Abstract
A series of 14 (E)-cinnamic N-acylhydrazone derivatives, designed through molecular hybridization between the (E)-1-(benzo[d][1,3]dioxol-5-yl)-3-(4-bromophenyl)prop-2-en-1-one and (E)-3-hydroxy-N'-((2-hydroxynaphthalen-1-yl)methylene)-7-methoxy-2-naphthohydrazide, were tested for in vitro antiparasitic activity upon axenic amastigote forms of Leishmania donovani and bloodstream
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A series of 14 (E)-cinnamic N-acylhydrazone derivatives, designed through molecular hybridization between the (E)-1-(benzo[d][1,3]dioxol-5-yl)-3-(4-bromophenyl)prop-2-en-1-one and (E)-3-hydroxy-N'-((2-hydroxynaphthalen-1-yl)methylene)-7-methoxy-2-naphthohydrazide, were tested for in vitro antiparasitic activity upon axenic amastigote forms of Leishmania donovani and bloodstream forms of Trypamosoma brucei rhodesiense. The derivative (2E)-3-(4-hydroxy-3-methoxy-5-nitrophenyl)-N'-[(1E)-phenylmethylene]acrylohydrazide showed moderate antileishmanial activity (IC50 = 6.27 µM) when compared to miltefosine, the reference drug (IC50 = 0.348 µM). However, the elected compound showed an excellent selectivity index; in one case it was not cytotoxic against mammalian L-6 cells. The most active antitrypanosomal compound, the derivative (E)-N'-(3,4-dihydroxybenzylidene)cinnamohydrazide (IC50 = 1.93 µM), was cytotoxic against mammalian L-6 cells. Full article
(This article belongs to the Special Issue Cinnamic Acids Hybrids with Biological Interest)
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Open AccessArticle Chemical Constituents and Bioactivities of Clinacanthus nutans Aerial Parts
Molecules 2014, 19(12), 20382-20390; https://doi.org/10.3390/molecules191220382
Received: 27 October 2014 / Revised: 25 November 2014 / Accepted: 27 November 2014 / Published: 5 December 2014
Cited by 15 | PDF Full-text (701 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Four new sulfur-containing compounds, named clinamides A-C (13), and 2-cis-entadamide A (4), were isolated together with three known compounds from the bioactive ethanol extract of the aerial parts of Clinacanthus nutans. These secondary metabolites
[...] Read more.
Four new sulfur-containing compounds, named clinamides A-C (13), and 2-cis-entadamide A (4), were isolated together with three known compounds from the bioactive ethanol extract of the aerial parts of Clinacanthus nutans. These secondary metabolites possess sulfur atoms and acrylamide functionalities. The structures of the isolated components were established by interpretation of their spectroscopic data, especially 1D and 2D NMR. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Proton Adsorption Selectivity of Zeolites in Aqueous Media: Effect of Si/Al Ratio of Zeolites
Molecules 2014, 19(12), 20468-20481; https://doi.org/10.3390/molecules191220468
Received: 25 September 2014 / Revised: 1 December 2014 / Accepted: 3 December 2014 / Published: 8 December 2014
Cited by 12 | PDF Full-text (1243 KB) | HTML Full-text | XML Full-text
Abstract
In addition to their well-known uses as catalysts, zeolites are utilized to adsorb and remove various cations from aqueous system. The adsorption of the cations is ascribed to the negative charge of zeolites derived from isomorphous substitution of Si by Al. The amount
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In addition to their well-known uses as catalysts, zeolites are utilized to adsorb and remove various cations from aqueous system. The adsorption of the cations is ascribed to the negative charge of zeolites derived from isomorphous substitution of Si by Al. The amount of Na+ adsorption on 4A, X, Y, Na-P1 and mordenite type zeolites were determined in aqueous media, in a two-cation (Na+ and H+) system. Although each zeolite has a constant amount of negative charge, the amount of Na+ adsorption of each zeolite decreased drastically at low pH−pNa values, where pH−pNa is equal to log{(Na+)/(H+)}. By using the plot of the amount of Na+ adsorption versus pH−pNa, an index of the H+ selectivity, which is similar to the pKa of acids, of each zeolite was estimated, and the index tended to increase with decreasing Si/Al ratio of zeolites. These indicate that zeolites with lower Si/Al and higher negative charge density have higher H+ adsorption selectivity, and in fact, such a zeolite species (4A and X) adsorbed considerable amount of H+ even at weakly alkaline pH region. The adsorption of H+ results in the decrease of cation adsorption ability, and may lead to the dissolution of zeolites in aqueous media. Full article
(This article belongs to the Special Issue Zeolite Chemistry)
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Open AccessArticle A DFT Study of the Photochemical Dimerization of Methyl 3-(2-Furyl)acrylate and Allyl Urocanate
Molecules 2014, 19(12), 20482-20497; https://doi.org/10.3390/molecules191220482
Received: 12 September 2014 / Revised: 20 November 2014 / Accepted: 1 December 2014 / Published: 8 December 2014
Cited by 3 | PDF Full-text (1264 KB) | HTML Full-text | XML Full-text
Abstract
A DFT study of the photochemical dimerization of methyl 3-(2-furyl)acrylate is reported. The photochemical reaction gave a mixture of two dimers with high regioselectivity and good stereoselectivity. Calculations showed that benzophenone was able to act as a photosensitizer of the reaction. This compound
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A DFT study of the photochemical dimerization of methyl 3-(2-furyl)acrylate is reported. The photochemical reaction gave a mixture of two dimers with high regioselectivity and good stereoselectivity. Calculations showed that benzophenone was able to act as a photosensitizer of the reaction. This compound populated the first excited triplet state of the substrate. The frontier orbitals interaction between LSOMO of the triplet state and HOMO of the ground state accounted for the observed high regioselectivity. Furthermore, the energy of all the possible triplet biradicals has been calculated, showing that the precursor of the main product was the triplet biradical with the lowest energy. The coupling of the atomic coefficients on the radical centres in the biradical intermediates allowed to justify the observed products. The same behavior was observed in the case of the photochemical dimerization of an urocanate ester and in the dimerization of liquid methyl cinnamate. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Polyphenolic Profile, Antioxidant and Anti-Inflammatory Activity of Eastern Teaberry (Gaultheria procumbens L.) Leaf Extracts
Molecules 2014, 19(12), 20498-20520; https://doi.org/10.3390/molecules191220498
Received: 4 November 2014 / Revised: 28 November 2014 / Accepted: 1 December 2014 / Published: 8 December 2014
Cited by 11 | PDF Full-text (1345 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Dry leaf extracts of eastern teaberry (Gaultheria procumbens L.) were evaluated as a source of bioactive phytocompounds through systematic activity testing and phytochemical profiling. The antioxidant efficiency was tested using five complementary in vitro models (DPPH; FRAP; linoleic acid (LA) peroxidation assay;
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Dry leaf extracts of eastern teaberry (Gaultheria procumbens L.) were evaluated as a source of bioactive phytocompounds through systematic activity testing and phytochemical profiling. The antioxidant efficiency was tested using five complementary in vitro models (DPPH; FRAP; linoleic acid (LA) peroxidation assay; O2•− and H2O2 scavenging tests) in parallel with standard antioxidants. The 75% methanol extract and its diethyl ether, ethyl acetate (EAF), n-butanol and water fractions exhibited the dose-dependent responses in all assays, with the highest capacities found for EAF (DPPH EC50 = 2.9 μg/mL; FRAP = 12.8 mmol Fe2+/g; IC50 for LA-peroxidation = 123.9 μg/mL; O2•− SC50 = 3.9 μg/mL; H2O2 SC50 = 7.2 μg/mL). The EAF had also the highest anti-inflammatory activity in the inhibition tests of lipoxygenase and hyaluronidase (60.14% and 21.83% effects, respectively, at the concentration of 100 μg/mL). Activity parameters of the extracts correlated strongly with the levels of total phenolics (72.4–270.7 mg GAE/g), procyanidins, and phenolic acids, whereas for flavonoids only moderate effects were observed. Comprehensive UHPLC-PDA-ESI-MS3 and HPLC-PDA studies led to the identification of 35 polyphenols with a procyanidin A-type trimer, quercetin 3-O-glucuronide, isomers of caffeoylquinic acids, and (‒)-epicatechin being the dominant components. Significant activity levels, high phenolic contents and high extraction yields (39.4%–42.5% DW for defatted and crude methanol extracts, respectively) indicate the value of eastern teaberry leaves as bioactive products. Full article
(This article belongs to the Special Issue Natural Antioxidants and Ageing)
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Open AccessArticle Biflavans, Flavonoids, and a Dihydrochalcone from the Stem Wood of Muntingia calabura and Their Inhibitory Activities on Neutrophil Pro-Inflammatory Responses
Molecules 2014, 19(12), 20521-20535; https://doi.org/10.3390/molecules191220521
Received: 28 October 2014 / Revised: 24 November 2014 / Accepted: 4 December 2014 / Published: 8 December 2014
Cited by 4 | PDF Full-text (779 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Muntingia calabura (Tiliaceae) is commercially used in healthcare for the improvement of hypertension, myocardial infarction, spasm, and inflammatory conditions. Its fruits can be processed into jam and the leaves can be used for making tea. In the work reported herein a new biflavan,
[...] Read more.
Muntingia calabura (Tiliaceae) is commercially used in healthcare for the improvement of hypertension, myocardial infarction, spasm, and inflammatory conditions. Its fruits can be processed into jam and the leaves can be used for making tea. In the work reported herein a new biflavan, (M),(2S),(2''S)-,(P),(2S),(2''S)-7,8,3',4',5',7'',8'',3''',4''',5'''-decamethoxy-5,5'' biflavan (1), a new flavone, 4'-hydroxy-7,8,3',5'-tetramethoxyflavone (2), and a new dihydrochalcone, (R)-2',β-dihydroxy-3',4'-dimethoxydihydrochalcone (3), have been isolated from the stem wood of M. calabura, together with 12 known compounds (415). The structures of these new compounds were elucidated by the interpretations of extensive spectroscopic data. Among the isolated compounds, 5-hydroxy-7-methoxyflavone (5), quercetin (6), and (2S)-7-hydroxyflavanone (10) exhibited potent inhibition of fMLP-induced superoxide anion generation by human neutrophils, with IC50 values of 1.77 ± 0.70, 3.82 ± 0.46, and 4.92 ± 1.71 μM, respectively. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle Resveratrol Inhibits Trophoblast Apoptosis through Oxidative Stress in Preeclampsia-Model Rats
Molecules 2014, 19(12), 20570-20579; https://doi.org/10.3390/molecules191220570
Received: 5 September 2014 / Revised: 16 November 2014 / Accepted: 17 November 2014 / Published: 9 December 2014
Cited by 13 | PDF Full-text (1861 KB) | HTML Full-text | XML Full-text
Abstract
Resveratrol has been shown to be a therapeutic agent for cardiovascular disorders by maintaining a lower redox level in vivo through its anti-oxidant properties. Resveratrol can prevent cells from p53- and reactive oxygen species-dependent apoptosis induced by interleukin-1b. We identified an inhibitory effect
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Resveratrol has been shown to be a therapeutic agent for cardiovascular disorders by maintaining a lower redox level in vivo through its anti-oxidant properties. Resveratrol can prevent cells from p53- and reactive oxygen species-dependent apoptosis induced by interleukin-1b. We identified an inhibitory effect of resveratrol against oxidative stress and apoptosis using the TUNEL assay in NG-Nitro-l-arginine methyl ester-induced preeclampsia in rats. To investigate a possible association between resveratrol and the apoptosis caused by oxidative stress in vitro, assays for superoxide dismutase and malondialdehyde as well as flow cytometric analyses were conducted in HTR-8/SVneo cells after hypoxic treatment with or without resveratrol for 24 h. These data suggest that resveratrol significantly opposes the effects of oxidative stress in vivo and in vitro. Full article
(This article belongs to the Special Issue Resveratrol)
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Open AccessArticle Vapour Phase Hydrogenation of Phenol over Rhodium on SBA-15 and SBA-16
Molecules 2014, 19(12), 20594-20612; https://doi.org/10.3390/molecules191220594
Received: 22 September 2014 / Revised: 17 November 2014 / Accepted: 24 November 2014 / Published: 10 December 2014
Cited by 2 | PDF Full-text (4048 KB) | HTML Full-text | XML Full-text
Abstract
In the present work, mesoporous SBA-15 and SBA-16 were synthesised using classical methods, and their physicochemical properties were investigated by X-ray diffraction (XRD), FTIR, TEM and N2 adsorption–desorption. Rhodium (Rh, 1 wt %) was loaded on the mesoporous SBA-15 and SBA-16 by
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In the present work, mesoporous SBA-15 and SBA-16 were synthesised using classical methods, and their physicochemical properties were investigated by X-ray diffraction (XRD), FTIR, TEM and N2 adsorption–desorption. Rhodium (Rh, 1 wt %) was loaded on the mesoporous SBA-15 and SBA-16 by an impregnation method. The Rh surface coverage, dispersion and crystallite size were determined by room temperature H2 chemisorption on reduced samples. The catalytic activity of Rh supported on mesoporous SBA-15 and SBA-16 was evaluated for the first time in the hydrogenation of phenol in vapour phase in a temperature range between 130 and 270 °C at atmospheric pressure. The reaction over Rh/SBA-15 at 180 °C produced cyclohexanone as the major product (about 60%) along with lower amounts of cyclohexanol (about 35%) and cyclohexane (about 15%). The influences of temperature, H2/phenol ratio, contact time and the nature of the solvent on the catalytic performance were systematically investigated. The Rh/SBA-16 system offered lower phenol conversion compared to Rh/SBA-15, but both have a very high selectivity for cyclohexanone (above 60%). Full article
(This article belongs to the Special Issue Zeolite Chemistry)
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Open AccessArticle Pharmacokinetics, Tissue Distribution and Excretion of Verticinone from F. hupehensis in Rats
Molecules 2014, 19(12), 20613-20626; https://doi.org/10.3390/molecules191220613
Received: 19 October 2014 / Revised: 25 November 2014 / Accepted: 4 December 2014 / Published: 10 December 2014
Cited by 5 | PDF Full-text (715 KB) | HTML Full-text | XML Full-text
Abstract
Verticinone, the main active component in F. hupehensis, exhibits potent antitussive and expectorant effects. Here, a LC-MS method was developed and applied to study the pharmacokinetics, tissue distribution and excretion of verticinone in rats, and its plasma protein binding in vitro.
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Verticinone, the main active component in F. hupehensis, exhibits potent antitussive and expectorant effects. Here, a LC-MS method was developed and applied to study the pharmacokinetics, tissue distribution and excretion of verticinone in rats, and its plasma protein binding in vitro. A significant gender difference in the pharmacokinetics of verticinone in rats was observed, as its absolute oral bioavailability in male and female rats was 45.8% and 2.74%, respectively. The relative bioavailability of verticinone was significantly lower in female rats as compared to male, following intragastrical (i.g.) and intravenous (i.v.) administration. After successive i.g. administration of verticinone, accumulation was observed in female rats but not in the male ones. The tissue distribution study showed that verticinone had a good tissue penetrability and a high tissue affinity in most studied tissues, except brain. After a 2 mg/kg oral dose, less than 4% of the dose was excreted as unchanged parent compound in male rats, and less than 1% in female rats, which indicated that verticinone was metabolized more extensively in female rats than in male rats. Full article
(This article belongs to the Section Metabolites)
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Open AccessArticle Determination and Occurrence of Phenoxyacetic Acid Herbicides and Their Transformation Products in Groundwater Using Ultra High Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry
Molecules 2014, 19(12), 20627-20649; https://doi.org/10.3390/molecules191220627
Received: 29 October 2014 / Revised: 26 November 2014 / Accepted: 27 November 2014 / Published: 10 December 2014
Cited by 12 | PDF Full-text (2296 KB) | HTML Full-text | XML Full-text
Abstract
A sensitive method was developed and validated for ten phenoxyacetic acid herbicides, six of their main transformation products (TPs) and two benzonitrile TPs in groundwater. The parent compounds mecoprop, mecoprop-p, 2,4-D, dicamba, MCPA, triclopyr, fluroxypr, bromoxynil, bentazone, and 2,3,6-trichlorobenzoic acid (TBA) are included
[...] Read more.
A sensitive method was developed and validated for ten phenoxyacetic acid herbicides, six of their main transformation products (TPs) and two benzonitrile TPs in groundwater. The parent compounds mecoprop, mecoprop-p, 2,4-D, dicamba, MCPA, triclopyr, fluroxypr, bromoxynil, bentazone, and 2,3,6-trichlorobenzoic acid (TBA) are included and a selection of their main TPs: phenoxyacetic acid (PAC), 2,4,5-trichloro-phenol (TCP), 4-chloro-2-methylphenol (4C2MP), 2,4-dichlorophenol (DCP), 3,5,6-trichloro-2-pyridinol (T2P), and 3,5-dibromo-4-hydroxybenzoic acid (BrAC), as well as the dichlobenil TPs 2,6-dichlorobenzamide (BAM) and 3,5-dichlorobenzoic acid (DBA) which have never before been determined in Irish groundwater. Water samples were analysed using an efficient ultra-high performance liquid chromatography (UHPLC) method in an 11.9 min separation time prior to detection by tandem mass spectrometry (MS/MS). The limit of detection (LOD) of the method ranged between 0.00008 and 0.0047 µg·L−1 for the 18 analytes. All compounds could be detected below the permitted limits of 0.1 µg·L−1 allowed in the European Union (EU) drinking water legislation [1]. The method was validated according to EU protocols laid out in SANCO/10232/2006 with recoveries ranging between 71% and 118% at the spiked concentration level of 0.06 µg·L−1. The method was successfully applied to 42 groundwater samples collected across several locations in Ireland in March 2012 to reveal that the TPs PAC and 4C2MP were detected just as often as their parent active ingredients (a.i.) in groundwater. Full article
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Open AccessArticle Expanding Current Knowledge on the Chemical Composition and Antioxidant Activity of the Genus Lactarius
Molecules 2014, 19(12), 20650-20663; https://doi.org/10.3390/molecules191220650
Received: 6 November 2014 / Revised: 4 December 2014 / Accepted: 4 December 2014 / Published: 10 December 2014
Cited by 2 | PDF Full-text (770 KB) | HTML Full-text | XML Full-text
Abstract
Despite the presence of toxic compounds in inedible mushrooms, the question whether the chemical nutrients and non-nutrients compositions in edible and inedible Lactarius species are similar remains unanswered. To answer this question, Lactarius citriolens Pouzar and Lactarius turpis (Weinm.) Fr., two inedible species,
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Despite the presence of toxic compounds in inedible mushrooms, the question whether the chemical nutrients and non-nutrients compositions in edible and inedible Lactarius species are similar remains unanswered. To answer this question, Lactarius citriolens Pouzar and Lactarius turpis (Weinm.) Fr., two inedible species, were studied in order to obtain information about their chemical composition and bioactivity. Free sugars, fatty acids, tocopherols, organic and phenolic acids were analysed by chromatographic techniques coupled to different detectors. L. citriolens and L. turpis methanolic extracts were tested regarding antioxidant potential (reducing power, radical scavenging activity and lipid peroxidation inhibition). The composition of macronutrients varied among the two species, but the profiles were similar between them and among other Lactarius species; L. citriolens gave the highest energy contribution, saturated fatty acids and organic acids, while the L. turpis sample was richer in free sugars, mono- and polyunsaturated fatty acids, tocopherols and phenolic compounds. L. turpis methanolic extract showed the highest antioxidant activity. The absence of hepatoxicity of the methanolic extracts was confirmed in porcine liver primary cells (in vitro conditions). The present study provided new information about wild L. citriolens and L. turpis, comparing their chemical composition and antioxidant properties with other Lactarius species, and expanding the knowledge about this genus. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle Synthesis of Racemic β-Chamigrene, a Spiro[5.5]undecane Sesquiterpene
Molecules 2014, 19(12), 20664-20670; https://doi.org/10.3390/molecules191220664
Received: 13 October 2014 / Revised: 2 December 2014 / Accepted: 4 December 2014 / Published: 10 December 2014
Cited by 4 | PDF Full-text (666 KB) | HTML Full-text | XML Full-text
Abstract
The present paper describes a total synthesis of racemic β-chamigrene (1), a sesquiterpene with a spiro[5.5]undecane carbon framework. Compared with previously reported β-chamigrene syntheses, we were able to reduce the total number of reaction steps, which also resulted in a significant
[...] Read more.
The present paper describes a total synthesis of racemic β-chamigrene (1), a sesquiterpene with a spiro[5.5]undecane carbon framework. Compared with previously reported β-chamigrene syntheses, we were able to reduce the total number of reaction steps, which also resulted in a significant improvement of the overall yield. The commercially available ketone 6-methylhept-5-en-2-one was transformed by known simple procedures into 3,3-dimethyl-2-methylenecyclohexanone. This reacted with isoprene by a Diels-Alder reaction to give a spiro ketone. An olefination reaction on this compound gave the target molecule. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Synergistic Radiation Protective Effect of Purified Auricularia auricular-judae Polysaccharide (AAP IV) with Grape Seed Procyanidins
Molecules 2014, 19(12), 20675-20694; https://doi.org/10.3390/molecules191220675
Received: 3 November 2014 / Revised: 27 November 2014 / Accepted: 2 December 2014 / Published: 11 December 2014
Cited by 7 | PDF Full-text (1231 KB) | HTML Full-text | XML Full-text
Abstract
The aim of this study was to investigate the synergistic antioxidant potential and protective effect of grape seed procyanidins (GSP) in combination with Auricularia auricular-judae polysaccharides (AAP IV) on radiation injury in splenocytes. Rat splenocyte irradiation resulted in significantly higher apoptosis rate,
[...] Read more.
The aim of this study was to investigate the synergistic antioxidant potential and protective effect of grape seed procyanidins (GSP) in combination with Auricularia auricular-judae polysaccharides (AAP IV) on radiation injury in splenocytes. Rat splenocyte irradiation resulted in significantly higher apoptosis rate, malondialdehyde (MDA) (p < 0.005), reactive oxygen species (ROS) (p < 0.01); cell viability, total superoxide dismutase (T-SOD) (p < 0.01), catalase (CAT) (p < 0.01), glutathione peroxidase (GSH-PX) (p < 0.05), activity and glutathione (GSH) (p < 0.01) levels were significantly reduced, compared with the control group. “GSP + AAP IV” treatment of rat splenocytes at doses of “GSP (0.3 μg/mL) + AAP IV (50 μg/mL)” displayed higher radioprotective and antioxidative effects than the administration of either GSP or AAP IV, as evident by lower levels of MDA (p < 0.001) concentration, as well as higher cell viability and T-SOD (p < 0.05), CAT (p < 0.005), GSH-PX (p < 0.01) and GSH content compared to the radiation group. In addition, in vivo studies have shown that “GSP + AAP IV” significantly ameliorated the decrease of spleen index (p < 0.005) and spleen GSH (p < 0.005) levels and significantly inhibited the increase of MDA (p < 0.005) levels of spleen with radiation-induced damage, compared with the non-treated group. The in vivo and in vitro results suggested that GSP and AAP IV have a synergistic protective effect against radiation-induced injury by improving the antioxidant and immunomodulation activities. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Photochemistry of Benzotriazoles: Generation of 1,3-Diradicals and Intermolecular Cycloaddition as a New Route toward Indoles and Dihydropyrrolo[3,4-b]Indoles
Molecules 2014, 19(12), 20695-20708; https://doi.org/10.3390/molecules191220695
Received: 4 November 2014 / Revised: 26 November 2014 / Accepted: 27 November 2014 / Published: 11 December 2014
Cited by 5 | PDF Full-text (1126 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Irradiation of benzotriazoles 1ae at λ = 254 nm in acetonitrile solution generated the corresponding 1,3-diradicals which underwent intermolecular cycloaddition with maleimides to afford the corresponding dihydropyrrolo[3,4-b]indoles and with acetylene derivatives to afford indoles as the major products. This
[...] Read more.
Irradiation of benzotriazoles 1ae at λ = 254 nm in acetonitrile solution generated the corresponding 1,3-diradicals which underwent intermolecular cycloaddition with maleimides to afford the corresponding dihydropyrrolo[3,4-b]indoles and with acetylene derivatives to afford indoles as the major products. This offers an interesting and simple access to such ring systems of potential synthetic and biological interest. The structures of the photoproducts were established spectroscopically and by single crystal X-ray crystallography. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Chemically Synthesized Glycosides of Hydroxylated Flavylium Ions as Suitable Models of Anthocyanins: Binding to Iron Ions and Human Serum Albumin, Antioxidant Activity in Model Gastric Conditions
Molecules 2014, 19(12), 20709-20730; https://doi.org/10.3390/molecules191220709
Received: 5 October 2014 / Revised: 15 November 2014 / Accepted: 2 December 2014 / Published: 11 December 2014
Cited by 4 | PDF Full-text (909 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Polyhydroxylated flavylium ions, such as 3',4',7-trihydroxyflavylium chloride (P1) and its more water-soluble 7-O-β-d-glucopyranoside (P2), are readily accessible by chemical synthesis and suitable models of natural anthocyanins in terms of color and species distribution in aqueous solution. Owing to their catechol B-ring,
[...] Read more.
Polyhydroxylated flavylium ions, such as 3',4',7-trihydroxyflavylium chloride (P1) and its more water-soluble 7-O-β-d-glucopyranoside (P2), are readily accessible by chemical synthesis and suitable models of natural anthocyanins in terms of color and species distribution in aqueous solution. Owing to their catechol B-ring, they rapidly bind FeIII, weakly interact with FeII and promote its autoxidation to FeIII. Both pigments inhibit heme-induced lipid peroxidation in mildly acidic conditions (a model of postprandial oxidative stress in the stomach), the colorless (chalcone) forms being more potent than the colored forms. Finally, P1 and P2 are moderate ligands of human serum albumin (HSA), their likely carrier in the blood circulation, with chalcones having a higher affinity for HSA than the corresponding colored forms. Full article
(This article belongs to the Special Issue Anthocyanins) Printed Edition available
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Open AccessArticle Investigation of Dendriplexes by Ion Mobility-Mass Spectrometry
Molecules 2014, 19(12), 20731-20750; https://doi.org/10.3390/molecules191220731
Received: 24 July 2014 / Revised: 22 October 2014 / Accepted: 27 October 2014 / Published: 12 December 2014
Cited by 1 | PDF Full-text (3141 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Highly branched polyamidoamine (PAMAM) dendrimers presenting biological activities have been envisaged as non-viral gene delivery vectors. They are known to associate with nucleic acid (DNA) in non-covalent complexes via electrostatic interactions. Although their transfection efficiency has been proved, PAMAMs present a significant cytotoxicity
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Highly branched polyamidoamine (PAMAM) dendrimers presenting biological activities have been envisaged as non-viral gene delivery vectors. They are known to associate with nucleic acid (DNA) in non-covalent complexes via electrostatic interactions. Although their transfection efficiency has been proved, PAMAMs present a significant cytotoxicity due to their cationic surface. To overcome such a drawback, different chemical modifications of the PAMAM surface have been reported such as the attachment of hydrophobic residues. In the present work, we studied the complexation of DNA duplexes with different low-generation PAMAM; ammonia-cored G0(N) and G1(N) PAMAM, native or chemically modified with aromatic residues, i.e., phenyl-modified-PAMAM G0(N) and phenylalanine-modified-PAMAM G1(N). To investigate the interactions involved in the PAMAM/DNA complexes, also called dendriplexes, we used electrospray ionization (ESI) coupled to ion mobility spectrometry-mass-spectrometry (IM-MS). ESI is known to allow the study of non-covalent complexes in native conditions while IM-MS is a bidimensional separation technique particularly useful for the characterization of complex mixtures. IM-MS allows the separation of the expected complexes, possible additional non-specific complexes and the free ligands. Tandem mass spectrometry (MS/MS) was also used for the structural characterization. This work highlights the contribution of IM-MS and MS/MS for the study of small dendriplexes. The stoichiometries of the complexes and the equilibrium dissociation constants were determined. The [DNA/native PAMAM] and [DNA/modified-PAMAM] dendriplexes were compared. Full article
(This article belongs to the Special Issue Dendrimers in Medicine and Biotechnology)
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Open AccessArticle Bio-Inspired Nitrile Hydration by Peptidic Ligands Based on L-Cysteine, L-Methionine or L-Penicillamine and Pyridine-2,6-dicarboxylic Acid
Molecules 2014, 19(12), 20751-20767; https://doi.org/10.3390/molecules191220751
Received: 2 September 2014 / Revised: 6 November 2014 / Accepted: 16 November 2014 / Published: 12 December 2014
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Abstract
Nitrile hydratase (NHase, EC 4.2.1.84) is a metalloenzyme which catalyses the conversion of nitriles to amides. The high efficiency and broad substrate range of NHase have led to the successful application of this enzyme as a biocatalyst in the industrial syntheses of acrylamide
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Nitrile hydratase (NHase, EC 4.2.1.84) is a metalloenzyme which catalyses the conversion of nitriles to amides. The high efficiency and broad substrate range of NHase have led to the successful application of this enzyme as a biocatalyst in the industrial syntheses of acrylamide and nicotinamide and in the bioremediation of nitrile waste. Crystal structures of both cobalt(III)- and iron(III)-dependent NHases reveal an unusual metal binding motif made up from six sequential amino acids and comprising two amide nitrogens from the peptide backbone and three cysteine-derived sulfur ligands, each at a different oxidation state (thiolate, sulfenate and sulfinate). Based on the active site geometry revealed by these crystal structures, we have designed a series of small-molecule ligands which integrate essential features of the NHase metal binding motif into a readily accessible peptide environment. We report the synthesis of ligands based on a pyridine-2,6-dicarboxylic acid scaffold and L-cysteine, L-S-methylcysteine, L-methionine or L-penicillamine. These ligands have been combined with cobalt(III) and iron(III) and tested as catalysts for biomimetic nitrile hydration. The highest levels of activity are observed with the L-penicillamine ligand which, in combination with cobalt(III), converts acetonitrile to acetamide at 1.25 turnovers and benzonitrile to benzamide at 1.20 turnovers. Full article
(This article belongs to the Special Issue Peptide Chemistry)
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Open AccessArticle Up-Regulation of Urotensin II and Its Receptor Contributes to Human Hepatocellular Carcinoma Growth via Activation of the PKC, ERK1/2, and p38 MAPK Signaling Pathways
Molecules 2014, 19(12), 20768-20779; https://doi.org/10.3390/molecules191220768
Received: 17 September 2014 / Revised: 27 November 2014 / Accepted: 5 December 2014 / Published: 12 December 2014
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Abstract
Urotensin II (UII) and its receptor (UTR) have mitogenic effects on tumor growth. Our previous study demonstrated that the UII/UTR system is up-regulated in dithyinitrosamine-induced precancerous rat liver lesions. However, its role in human hepatocellular carcinoma remains unknown. In this study, the mRNA
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Urotensin II (UII) and its receptor (UTR) have mitogenic effects on tumor growth. Our previous study demonstrated that the UII/UTR system is up-regulated in dithyinitrosamine-induced precancerous rat liver lesions. However, its role in human hepatocellular carcinoma remains unknown. In this study, the mRNA and protein expression of UII and its receptor (UTR) in human hepatocellular carcinoma samples and in the BEL-7402 human hepatoma cell line were evaluated. In addition, the effect of exogenous UII on the pathways that regulate proliferation in BEL-7402 cells in vitro were determined. Liver sections were subjected to immunohistochemical staining. mRNA expression was detected by real-time polymerase chain reaction analysis, and protein levels were evaluated by western blotting. Proliferating cells were detected by BrdU incorporation. The expression of UII/UT mRNA and protein significantly increased in human hepatocellular carcinoma samples, and in BEL-7402 cells. Administration with UII increased the phosphorylation of protein kinase C (PKC), extracellular signal-regulated kinase (ERK1/2) and p38 mitogen-activated protein kinases (p38 MAPK). Furthermore, GF109203x, PD184352, and SB203580 partially abolished UII-induced proliferation of BEL-7402 cells. These results provide the first evidence that up-regulation of the UII/UT system may enhance proliferation of the human hepatoma cell line at least in part via PKC, ERK1/2, and p38 MAPK signaling pathways, and may provide novel therapeutic targets for inhibiting human hepatocellular carcinoma. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Optimization of Ultrasonic-Assisted Extraction of Cordycepin from Cordyceps militaris Using Orthogonal Experimental Design
Molecules 2014, 19(12), 20808-20820; https://doi.org/10.3390/molecules191220808
Received: 10 November 2014 / Revised: 4 December 2014 / Accepted: 8 December 2014 / Published: 12 December 2014
Cited by 14 | PDF Full-text (794 KB) | HTML Full-text | XML Full-text
Abstract
This study reports on the optimization of the extraction conditions of cordycepin from Cordyceps militaris by using ultrasonication. For this purpose, the orthogonal experimental design was used to investigate the effects of factors on the ultrasonic-assisted extraction (UAE). Four factors: extraction time (min),
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This study reports on the optimization of the extraction conditions of cordycepin from Cordyceps militaris by using ultrasonication. For this purpose, the orthogonal experimental design was used to investigate the effects of factors on the ultrasonic-assisted extraction (UAE). Four factors: extraction time (min), ethanol concentration (%), extraction temperature (°C) and extraction frequency (kHz), were studied. The results showed that the highest cordycepin yield of 7.04 mg/g (86.98% ± 0.23%) was obtained with an extraction time of 60 min, ethanol concentration of 50%, extraction temperature of 65 °C and extraction frequency of 56 kHz. It was found that the cordycepin extraction yield increased with the effect of ultrasonication during the extraction process. Therefore, UAE can be used as an alternative to conventional immersion extraction with respect to the recovery of cordycepin from C. militaris, with the advantages of shorter extraction time and reduced solvent consumption. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Antioxidant Properties of Pyroligneous Acid Obtained by Thermochemical Conversion of Schisandra chinensis Baill
Molecules 2014, 19(12), 20821-20838; https://doi.org/10.3390/molecules191220821
Received: 13 October 2014 / Revised: 8 December 2014 / Accepted: 9 December 2014 / Published: 12 December 2014
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Abstract
Sustainable development of renewable resources is a major challenge globally. Biomass is an important renewable energy source and an alternative to fossil fuels. Pyrolysis of biomass is a promising method for simultaneous production of biochar, bio-oil, pyroligneous acid (PA), and gaseous fuels. The
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Sustainable development of renewable resources is a major challenge globally. Biomass is an important renewable energy source and an alternative to fossil fuels. Pyrolysis of biomass is a promising method for simultaneous production of biochar, bio-oil, pyroligneous acid (PA), and gaseous fuels. The purpose of this study was to investigate the pyrolysis process and products yields of Schisandra chinensis fruits with different pyrolysis powers. The obtained PA was extracted with organic solvents, including ethyl formate, dichloromethane, methanol and tetrahydrofuran. The antioxidant activities, including the free radical scavenging activity and ferric reducing power, of the PA extracts were investigated. The synthetic antioxidants butylated hydroxyanisole and butylated hydroxytoluene were used as positive controls. A dichloromethane extract of PA showed excellent antioxidant properties compared to the other extracts. The chemical compositions of the PA extracts were determined by GC-MS, and further proved that the dichloromethane extract had the best antioxidant characteristics among the extracts tested. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Two New Coumarins from Talaromyces flavus
Molecules 2014, 19(12), 20880-20887; https://doi.org/10.3390/molecules191220880
Received: 22 October 2014 / Revised: 28 November 2014 / Accepted: 9 December 2014 / Published: 12 December 2014
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Abstract
Two new coumarins, talacoumarins A (1) and B (2), were isolated from the ethyl acetate extract of the wetland soil-derived fungus Talaromyces flavus BYD07-13. Their structures were elucidated by spectroscopic data (NMR, MS) analyses. The absolute configuration of C-12
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Two new coumarins, talacoumarins A (1) and B (2), were isolated from the ethyl acetate extract of the wetland soil-derived fungus Talaromyces flavus BYD07-13. Their structures were elucidated by spectroscopic data (NMR, MS) analyses. The absolute configuration of C-12 in 1 was assigned using the modified Mosher’s method, whereas that of C-12 in 2 was deduced via the circular dichroism data of its corresponding [Rh2(OCOCF3)4] complex. Compounds 1 and 2 were evaluated for their anti-Aβ42 aggregation, cytotoxic, and antimicrobial activities. The results showed that the two compounds had moderate anti-Aβ42 aggregation activity, and this is the first report on the Aβ42 inhibitory aggregation activity of coumarins. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Combined Dynamic Light Scattering and Raman Spectroscopy Approach for Characterizing the Aggregation of Therapeutic Proteins
Molecules 2014, 19(12), 20888-20905; https://doi.org/10.3390/molecules191220888
Received: 7 November 2014 / Revised: 2 December 2014 / Accepted: 5 December 2014 / Published: 12 December 2014
Cited by 14 | PDF Full-text (2157 KB) | HTML Full-text | XML Full-text
Abstract
Determination of the physicochemical properties of protein therapeutics and their aggregates is critical for developing formulations that enhance product efficacy, stability, safety and manufacturability. Analytical challenges are compounded for materials: (1) that are formulated at high concentration, (2) that are formulated with a
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Determination of the physicochemical properties of protein therapeutics and their aggregates is critical for developing formulations that enhance product efficacy, stability, safety and manufacturability. Analytical challenges are compounded for materials: (1) that are formulated at high concentration, (2) that are formulated with a variety of excipients, and (3) that are available only in small volumes. In this article, a new instrument is described that measures protein secondary and tertiary structure, as well as molecular size, over a range of concentrations and formulation conditions of low volume samples. Specifically, characterization of colloidal and conformational stability is obtained through a combination of two well-established analytical techniques: dynamic light scattering (DLS) and Raman spectroscopy, respectively. As the data for these two analytical modalities are collected on the same sample at the same time, the technique enables direct correlation between them, in addition to the more straightforward benefit of minimizing sample usage by providing multiple analytical measurements on the same aliquot non-destructively. The ability to differentiate between unfolding and aggregation that the combination of these techniques provides enables insights into underlying protein aggregation mechanisms. The article will report on mechanistic insights for aggregation that have been obtained from the application of this technique to the characterization of lysozyme, which was evaluated as a function of concentration and pH. Full article
(This article belongs to the Special Issue Advances of Vibrational Spectroscopic Technologies in Life Sciences)
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Open AccessArticle Total Synthesis and Anti-Viral Activities of an Extract of Radix isatidis
Molecules 2014, 19(12), 20906-20912; https://doi.org/10.3390/molecules191220906
Received: 12 November 2014 / Revised: 7 December 2014 / Accepted: 9 December 2014 / Published: 12 December 2014
Cited by 2 | PDF Full-text (711 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Radix isatidis (Banlangen), a famous traditional Chinese medicine, has been used for thousands of years in China due to its anti-viral activity. Through our research, we inferred that the anti-viral activity of Radix isatidis depended on the water-soluble part. Among the components of
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Radix isatidis (Banlangen), a famous traditional Chinese medicine, has been used for thousands of years in China due to its anti-viral activity. Through our research, we inferred that the anti-viral activity of Radix isatidis depended on the water-soluble part. Among the components of this extract, the isoquinoline derivative 1 was isolated for the first time and has shown better anti-viral activity than other constituents. In this study, to solve the problem of sourcing sufficient quantities of compound 1, a total synthesis route is described, and several analogues are also evaluated for their anti-viral activities. Among them, compound 8 shown potent anti-viral activity with an IC50 value of 15.3 µg/mL. The results suggested that isoquinoline derivatives possessed potent anti-viral activity and are worthy further development. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle An Insecticidal Compound Produced by an Insect-Pathogenic Bacterium Suppresses Host Defenses through Phenoloxidase Inhibition
Molecules 2014, 19(12), 20913-20928; https://doi.org/10.3390/molecules191220913
Received: 5 November 2014 / Revised: 3 December 2014 / Accepted: 9 December 2014 / Published: 12 December 2014
Cited by 11 | PDF Full-text (961 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A bioassay-guided column chromatographic strategy was adopted in the present study to fractionate the culture extract of Photorhabdus temperata M1021 to identify potential insecticidal and antimicrobial compounds. An ethyl acetate (EtOAc) culture extract of P. temperata was assayed against Galleria mellonella larvae through
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A bioassay-guided column chromatographic strategy was adopted in the present study to fractionate the culture extract of Photorhabdus temperata M1021 to identify potential insecticidal and antimicrobial compounds. An ethyl acetate (EtOAc) culture extract of P. temperata was assayed against Galleria mellonella larvae through intra-hemocoel injection and exhibited 100% insect mortality within 60 h. The EtOAc fraction and an isolated compound exhibited phenoloxidase (PO) inhibition of up to 60% and 63%, respectively. The compound was identified as 1,2-benzenedicarboxylic acid (phthalic acid, PA) by gas chromatography-mass spectrometry and nuclear magnetic resonance. PA exhibited insecticidal activity against G. mellonella in a dose-dependent manner, and 100% insect mortality was observed at 108 h after injection of 1 M PA. In a PO inhibition assay, 0.5 and 1 M concentrations of PA were found to inhibit PO activity by 74% and 82%, respectively; and in a melanotic nodule formation assay, nodule formation was significantly inhibited (27 and 10 nodules) by PA (0.5 and 1 M, respectively). PA was furthermore found to have substantial antioxidant activity and maximum antioxidant activity was 64.7% for 0.5 M PA as compare to control. Antibacterial activity was assessed by The MIC values ranged from 0.1 M to 0.5 M of PA. This study reports a multifunctional PA, a potential insecticidal agent, could a factor of insect mortality along with other toxins produced by P. temperata M1021. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle The Biological Activities of Cinnamon, Geranium and Lavender Essential Oils
Molecules 2014, 19(12), 20929-20940; https://doi.org/10.3390/molecules191220929
Received: 24 October 2014 / Revised: 24 November 2014 / Accepted: 3 December 2014 / Published: 12 December 2014
Cited by 12 | PDF Full-text (802 KB) | HTML Full-text | XML Full-text
Abstract
Acinetobacter sp. represent an important cause of nosocomial infections. Their resistance to some antibiotics, their ability to survive on inanimate surfaces in the hospital environment and their ability to produce biofilms contributes to their virulence. The aim of the study was to determine
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Acinetobacter sp. represent an important cause of nosocomial infections. Their resistance to some antibiotics, their ability to survive on inanimate surfaces in the hospital environment and their ability to produce biofilms contributes to their virulence. The aim of the study was to determine the antibacterial properties of cinnamon, lavender and geranium essential oils against bacteria of the genus Acinetobacter isolated from several clinical materials and from the hospital environment. A comprehensive evaluation of the susceptibility of Acinetobacter sp. clinical strains to recommended antibiotics was performed. The constituents of cinnamon, lavender and geranium essential oils were identified by GC-FID-MS analysis, and their Minimal Inhibitory Concentrations (MICs) against tested clinical strains were determined by the micro-dilution broth method. In addition, the effects of essential oils on the viability of human microvascular endothelial cells (HMEC-1) and glioblastoma cell line (T98G) were evaluated. Cinnamon bark oil was the most active against clinical and environmental strains of Acinetobacter baumannii with MIC values ranging from 0.5 to 2.5 µL/mL. The MIC values for geranium oil were between 7.5 and 9.5 µL/mL, and between 10.5 and 13.0 µL/mL for lavender oil. These essential oils can be best employed in the fight against infections caused by bacteria from Acinetobacter genus as components of formulations for hygiene and disinfection of hospital environment. Full article
(This article belongs to the collection Bioactive Compounds)
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