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Molecules, Volume 18, Issue 6 (June 2013), Pages 6128-7335

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Open AccessArticle Herb-Drug Interaction of Epimedium sagittatum (Sieb. et Zucc.) Maxim Extract on the Pharmacokinetics of Sildenafil in Rats
Molecules 2013, 18(6), 7323-7335; https://doi.org/10.3390/molecules18067323
Received: 9 April 2013 / Revised: 16 May 2013 / Accepted: 19 June 2013 / Published: 21 June 2013
Cited by 10 | Viewed by 4542 | PDF Full-text (323 KB) | HTML Full-text | XML Full-text
Abstract
Epimedium sagittatum (Sieb. et Zucc.) Maxim is one of the herbs used to treat erectile dysfunction in Traditional Chinese Medicine. Sildenafil is a phosphodiesterase 5 inhibitor used to treat erectile dysfunction in Western Medicine. This study evaluates the herbal-drug interaction of Epimedium sagittatum
[...] Read more.
Epimedium sagittatum (Sieb. et Zucc.) Maxim is one of the herbs used to treat erectile dysfunction in Traditional Chinese Medicine. Sildenafil is a phosphodiesterase 5 inhibitor used to treat erectile dysfunction in Western Medicine. This study evaluates the herbal-drug interaction of Epimedium sagittatum extract on the pharmacokinetics of sildenafil in rats by ultra-performance liquid chromatography. The rat plasma was sampled from each anesthetized rat after pretreatment with 3-days Epimedium sagittatum extract (1/2 g/kg/day) and intravenous injection with sildenafil (10/30 mg/kg). The pharmacokinetic data demonstrate that the area under the concentration-time curve (AUC) of sildenafil (10 mg/kg) was significantly decreased in groups that received a high dose of Epimedium sagittatum extract. In conclusion, the study demonstrates that there was significant herb-drug interaction of Epimedium sagittatum extract on the pharmacokinetics of sildenafil at low and high daily doses, suggesting co-administration use of Epimedium sagittatum extract and sildenafil in clinical practice should be prevented due to possible herb-drug interactions. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Monoterpenoid Indole Alkaloids from Alstonia rupestris with Cytotoxic, Anti-Inflammatory and Antifungal Activities
Molecules 2013, 18(6), 7309-7322; https://doi.org/10.3390/molecules18067309
Received: 22 April 2013 / Revised: 3 June 2013 / Accepted: 9 June 2013 / Published: 21 June 2013
Cited by 12 | Viewed by 3201 | PDF Full-text (371 KB) | HTML Full-text | XML Full-text
Abstract
Phytochemical investigation of the 70% EtOH extract of the leaves of Alstonia scholaris afforded seven new monoterpenoid indole alkaloids: scholarisins I-VII (1-7), and three known compounds: (3R,5S,7R,15R,16R,19E)-scholarisine F (
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Phytochemical investigation of the 70% EtOH extract of the leaves of Alstonia scholaris afforded seven new monoterpenoid indole alkaloids: scholarisins I-VII (1-7), and three known compounds: (3R,5S,7R,15R,16R,19E)-scholarisine F (8), 3-epi-dihydro- corymine (9), and (E)-16-formyl-5α-methoxystrictamine (10). Structural elucidation of all the compounds was accomplished by spectral methods such as 1D- and 2D-NMR, IR, UV, and HRESIMS. The isolated compounds were tested in vitro for cytotoxicity against seven tumor cell lines, anti-inflammatory activities against Cox-1 and Cox-2, and antifungal potential against five species of fungi. Compounds 1, 6, and 10 exhibited significant cytotoxicities against all the tested tumor cell lines with IC50 values of less than 30 μM and selective inhibition of Cox-2 comparable with the standard drug NS-398 (>90%). Additionally, 1, 2, 3 and 8 showed antifungal activity against two fungal strains (G. pulicaris and C. nicotianae). Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessReview Chemical Reactions Catalyzed by Metalloporphyrin-Based Metal-Organic Frameworks
Molecules 2013, 18(6), 7279-7308; https://doi.org/10.3390/molecules18067279
Received: 7 May 2013 / Revised: 3 June 2013 / Accepted: 13 June 2013 / Published: 21 June 2013
Cited by 50 | Viewed by 5266 | PDF Full-text (716 KB) | HTML Full-text | XML Full-text
Abstract
The synthetic versatility and the potential application of metalloporphyrins (MP) in different fields have aroused researchers’ interest in studying these complexes, in an attempt to mimic biological systems such as cytochrome P-450. Over the last 40 years, synthetic MPs have been mainly used
[...] Read more.
The synthetic versatility and the potential application of metalloporphyrins (MP) in different fields have aroused researchers’ interest in studying these complexes, in an attempt to mimic biological systems such as cytochrome P-450. Over the last 40 years, synthetic MPs have been mainly used as catalysts for homogeneous or heterogeneous chemical reactions. To employ them in heterogeneous catalysis, chemists have prepared new MP-based solids by immobilizing MP onto rigid inorganic supports, a strategy that affords hybrid inorganic-organic materials. More recently, materials obtained by supramolecular assembly processes and containing MPs as building blocks have been applied in a variety of areas, like gas storage, photonic devices, separation, molecular sensing, magnets, and heterogeneous catalysis, among others. These coordination polymers, known as metal-organic frameworks (MOFs), contain organic ligands or complexes connected by metal ions or clusters, which give rise to a 1-, 2- or 3-D network. These kinds of materials presents large surface areas, Brønsted or redox sites, and high porosity, all of which are desirable features in catalysts with potential use in heterogeneous phases. Building MOFs based on MP is a good way to obtain solid catalysts that offer the advantages of bioinspired systems and zeolitic materials. In this mini review, we will adopt a historical approach to present the most relevant MP-based MOFs applicable to catalytic reactions such as oxidation, reduction, insertion of functional groups, and exchange of organic functions. Full article
(This article belongs to the Special Issue Heterogeneous Catalysis)
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Open AccessArticle A Fully Automated Radiosynthesis of [18F]Fluoroethyl-Diprenorphine on a Single Module by Use of SPE Cartridges for Preparation of High Quality 2-[18F]Fluoroethyl Tosylate
Molecules 2013, 18(6), 7271-7278; https://doi.org/10.3390/molecules18067271
Received: 1 May 2013 / Revised: 16 May 2013 / Accepted: 4 June 2013 / Published: 20 June 2013
Cited by 6 | Viewed by 3476 | PDF Full-text (300 KB) | HTML Full-text | XML Full-text
Abstract
We have developed a new method for automated production of 2-[18F]fluoroethyl tosylate ([18F]FETos) that enables 18F-alkylation to provide PET tracers with high chemical purity. The method is based on the removal of excess ethylene glycol bistosylate precursor by
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We have developed a new method for automated production of 2-[18F]fluoroethyl tosylate ([18F]FETos) that enables 18F-alkylation to provide PET tracers with high chemical purity. The method is based on the removal of excess ethylene glycol bistosylate precursor by precipitation and subsequent filtration and purification of the filtrate by means of solid phase extraction cartridges (SPE). The method is integrated to a single synthesis module and thereby provides the advantage over previous methods of not requiring HPLC purification, as demonstrated by the full radiosynthesis of the potent opioid receptor PET tracer [18F]fluoroethyldiprenorphine. Full article
(This article belongs to the Special Issue PET Chemistry in Molecular Imaging)
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Open AccessReview Natural Products as a Source of Anti-Inflammatory Agents Associated with Inflammatory Bowel Disease
Molecules 2013, 18(6), 7253-7270; https://doi.org/10.3390/molecules18067253
Received: 27 April 2013 / Revised: 5 June 2013 / Accepted: 14 June 2013 / Published: 19 June 2013
Cited by 50 | Viewed by 5823 | PDF Full-text (348 KB) | HTML Full-text | XML Full-text
Abstract
Accumulating epidemiological and clinical study indicates that inflammation is a significant risk factor to develop various human diseases such as inflammatory bowel disease (IBD), chronic asthma, rheumatoid arthritis, multiple sclerosis, and psoriasis. Suppressing inflammation is therefore important to control or prevent various diseases.
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Accumulating epidemiological and clinical study indicates that inflammation is a significant risk factor to develop various human diseases such as inflammatory bowel disease (IBD), chronic asthma, rheumatoid arthritis, multiple sclerosis, and psoriasis. Suppressing inflammation is therefore important to control or prevent various diseases. Among them, IBD is one of the major problems affecting people worldwide. IBD affects at least one in a thousand persons in many Western countries. Various natural products have been shown to safely suppress pro-inflammatory pathway and control IBD. In vivo and/or in vitro studies indicate that anti-IBD effects of natural products occur by inhibition of the expression of pro-inflammatory cytokines (for example, tumor necrosis factor-α (TNF-α), intercellular adhesion molecule expression and pro-inflammatory mediators (such as inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2), master transcription factors (such as nuclear factor-κB (NF-κB)), reactive oxygen species (ROS) and by improving the antioxidant activity. In this review, we summarize recent research focused on IBD and the effects that natural products have on IBD factors. Full article
(This article belongs to the Special Issue Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry)
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Open AccessArticle Enhancement of the Controlled-Release Properties of Chitosan Membranes by Crosslinking with Suberoyl Chloride
Molecules 2013, 18(6), 7239-7252; https://doi.org/10.3390/molecules18067239
Received: 6 May 2013 / Revised: 7 June 2013 / Accepted: 17 June 2013 / Published: 19 June 2013
Cited by 16 | Viewed by 2857 | PDF Full-text (1125 KB) | HTML Full-text | XML Full-text
Abstract
A novel crosslinking agent, suberoyl chloride, was used to crosslink N-phthaloyl acylated chitosan and improves the properties of chitosan membranes. Membranes with different crosslinking degrees were synthesized. The derivatives were characterized by Fourier transform infrared spectroscopy and 13C solid state nuclear
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A novel crosslinking agent, suberoyl chloride, was used to crosslink N-phthaloyl acylated chitosan and improves the properties of chitosan membranes. Membranes with different crosslinking degrees were synthesized. The derivatives were characterized by Fourier transform infrared spectroscopy and 13C solid state nuclear magnetic resonance spectroscopy, which indicated that the crosslinking degrees ranged from 0 to 7.4%. The permeabilities of various plant nutrients, including macroelements (N, P, K), microelements (Zn2+ and Cu2+), and a plant growth regulator (naphthylacetic acid), were varied by moderate changes in crosslinking degree, indicating that the controlled-release properties can be regulated in this way. The film-forming ability of native chitosan was maintained, whilst mechanical properties, hydrophobicity and controlled permeability were improved. These dramatic improvements occurred with a small amount of added suberoyl chloride; excessive crosslinking led to membranes with unwanted poor permeability. Thus, both the mechanical properties and permeability of the crosslinked membrane can be optimized. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessReview Supercritical Fluid Extraction of Plant Flavors and Fragrances
Molecules 2013, 18(6), 7194-7238; https://doi.org/10.3390/molecules18067194
Received: 15 May 2013 / Revised: 13 June 2013 / Accepted: 14 June 2013 / Published: 19 June 2013
Cited by 74 | Viewed by 7069 | PDF Full-text (843 KB) | HTML Full-text | XML Full-text
Abstract
Supercritical fluid extraction (SFE) of plant material with solvents like CO2, propane, butane, or ethylene is a topic of growing interest. SFE allows the processing of plant material at low temperatures, hence limiting thermal degradation, and avoids the use of toxic
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Supercritical fluid extraction (SFE) of plant material with solvents like CO2, propane, butane, or ethylene is a topic of growing interest. SFE allows the processing of plant material at low temperatures, hence limiting thermal degradation, and avoids the use of toxic solvents. Although today SFE is mainly used for decaffeination of coffee and tea as well as production of hop extracts on a large scale, there is also a growing interest in this extraction method for other industrial applications operating at different scales. In this review we update the literature data on SFE technology, with particular reference to flavors and fragrance, by comparing traditional extraction techniques of some industrial medicinal and aromatic crops with SFE. Moreover, we describe the biological activity of SFE extracts by describing their insecticidal, acaricidal, antimycotic, antimicrobial, cytotoxic and antioxidant properties. Finally, we discuss the process modelling, mass-transfer mechanisms, kinetics parameters and thermodynamic by giving an overview of SFE potential in the flavors and fragrances arena. Full article
(This article belongs to the Special Issue Flavors and Fragrances)
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Open AccessArticle Immunomodulatory Effect of Stichopus japonicus Acid Mucopolysaccharide on Experimental Hepatocellular Carcinoma in Rats
Molecules 2013, 18(6), 7179-7193; https://doi.org/10.3390/molecules18067179
Received: 3 May 2013 / Revised: 17 May 2013 / Accepted: 9 June 2013 / Published: 19 June 2013
Cited by 23 | Viewed by 3360 | PDF Full-text (4360 KB) | HTML Full-text | XML Full-text
Abstract
Stichopus japonicus acid mucopolysaccharide (SJAMP) is an important biologically active compound that can be extracted from the body wall of the sea cucumber. The present study investigated the anti-tumor and immunomodulatory effects of SJAMP in an experimental hepatocellular carcinoma (HCC) model in rats.
[...] Read more.
Stichopus japonicus acid mucopolysaccharide (SJAMP) is an important biologically active compound that can be extracted from the body wall of the sea cucumber. The present study investigated the anti-tumor and immunomodulatory effects of SJAMP in an experimental hepatocellular carcinoma (HCC) model in rats. Three doses of SJAMP (17.5 mg/kg, 35 mg/kg, and 70 mg/kg administered 5 days/week via oral gavage) were given to rats with diethylnitrosamine (DEN)-induced HCC. SJAMP treatment significantly inhibited DEN-induced HCC by reducing both the number and mean volume of nodules, decreasing serum a-fetoprotein (AFP) levels and proliferating cell nuclear antigen (PCNA) expression in liver, and increasing p21 expression. Furthermore, SJAMP decreased the serum levels of ALT, AST, GGT and TNF-α and increased serum IL-2. SJAMP administration also improved indices of spleen and thymus function and improved both macrophage phagocytosis and NK cell-mediated tumoricidal activity. Moreover, CD3+ and CD4+ T lymphocyte levels recovered significantly and the CD4+/CD8+ T cell ratio normalized in a dose-dependent manner. In conclusion, SJAMP effectively inhibited the growth of HCC through the stimulation of immune organs and tissue proliferation, leading to the enhancement of cellular immunity pathways in rats. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Synthesis and Radiolabelling of DOTA-Linked Glutamine Analogues with 67,68Ga as Markers for Increased Glutamine Metabolism in Tumour Cells
Molecules 2013, 18(6), 7160-7178; https://doi.org/10.3390/molecules18067160
Received: 1 April 2013 / Revised: 10 May 2013 / Accepted: 8 June 2013 / Published: 19 June 2013
Cited by 5 | Viewed by 3422 | PDF Full-text (511 KB) | HTML Full-text | XML Full-text
Abstract
DOTA-linked glutamine analogues with a C6- alkyl and polyethyleneglycol (PEG) chain between the chelating group and the L-glutamine moiety were synthesised and labelled with 67,68Ga using established methods. High yields were achieved for the radiolabelling of the molecules with both
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DOTA-linked glutamine analogues with a C6- alkyl and polyethyleneglycol (PEG) chain between the chelating group and the L-glutamine moiety were synthesised and labelled with 67,68Ga using established methods. High yields were achieved for the radiolabelling of the molecules with both radionuclides (>90%), although conversion of the commercially available 67Ga-citrate to the chloride species was a requirement for consistent high radiochemical yields. The generator produced 68Ga was in the [68Ga(OH)4] form. The 67Ga complexes and the 67Ga complexes were demonstrated to be stable in PBS buffer for a week. Uptake studies were performed with longer lived 67Ga analogues against four tumour cell lines, as well as uptake inhibition studies against L-glutamine, and two known amino acid transporter inhibitors. Marginal uptake was exhibited in the PEG variant radio-complex, and inhibition studies indicate this uptake is via a non-targeted amino acid pathway. Full article
(This article belongs to the Special Issue PET Chemistry in Molecular Imaging)
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Open AccessReview Applications of Azide-Based Bioorthogonal Click Chemistry in Glycobiology
Molecules 2013, 18(6), 7145-7159; https://doi.org/10.3390/molecules18067145
Received: 20 May 2013 / Revised: 12 June 2013 / Accepted: 14 June 2013 / Published: 19 June 2013
Cited by 38 | Viewed by 5332 | PDF Full-text (679 KB) | HTML Full-text | XML Full-text
Abstract
Click chemistry is a powerful chemical reaction with excellent bioorthogonality features: biocompatible, rapid and highly specific in biological environments. For glycobiology, bioorthogonal click chemistry has created a new method for glycan non-invasive imaging in living systems, selective metabolic engineering, and offered an elite
[...] Read more.
Click chemistry is a powerful chemical reaction with excellent bioorthogonality features: biocompatible, rapid and highly specific in biological environments. For glycobiology, bioorthogonal click chemistry has created a new method for glycan non-invasive imaging in living systems, selective metabolic engineering, and offered an elite chemical handle for biological manipulation and glycomics studies. Especially the [3 + 2] dipolar cycloadditions of azides with strained alkynes and the Staudinger ligation of azides and triarylphosphines have been widely used among the extant click reactions. This review focuses on the azide-based bioorthogonal click chemistry, describing the characteristics and development of these reactions, introducing some recent applications in glycobiology research, especially in glycan metabolic engineering, including glycan non-invasive imaging, glycomics studies and viral surface manipulation for drug discovery as well as other applications like activity-based protein profiling and carbohydrate microarrays. Full article
(This article belongs to the collection Advances in Click Chemistry)
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Open AccessArticle Novel Antimicrobial Peptide Dendrimers with Amphiphilic Surface and Their Interactions with Phospholipids — Insights from Mass Spectrometry
Molecules 2013, 18(6), 7120-7144; https://doi.org/10.3390/molecules18067120
Received: 9 April 2013 / Revised: 4 June 2013 / Accepted: 6 June 2013 / Published: 18 June 2013
Cited by 12 | Viewed by 3624 | PDF Full-text (977 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A series of new peptide dendrimers with amphiphilic surface, designed around a dendronized ornithine (Orn) core were synthesized and characterized by ESI-MS, 1H-, 13C- NMR, and CD spectrometry. An improved antimicrobial potency against S. aureus and E. coli was detected as
[...] Read more.
A series of new peptide dendrimers with amphiphilic surface, designed around a dendronized ornithine (Orn) core were synthesized and characterized by ESI-MS, 1H-, 13C- NMR, and CD spectrometry. An improved antimicrobial potency against S. aureus and E. coli was detected as a result of an increased charge, higher branching and variable lipophilicity of the residues located at the C-terminus. Minimal inhibitory concentration (MIC) values indicated that the selected dendrimers were not sensitive to the physiological concentration of Na+ and K+ ions (100 mM), but expressed reduced potency at 10 mM concentration of Mg2+ and Ca2+ ions. Circular dichroism (CD) curves measured under various conditions revealed structure and solvent-dependent curve evolution. ESI-MS studies of gas-phase interactions between selected dendrimers and both anionic (DMPG) and neutral (DMPC) phospholipids revealed the presence of variously charged dendrimer/phospholipid aggregates with 1:1 to 1:5 stoichiometry. The collision-induced fragmentation (CID) of the most abundant [dendrimer/phospholipid]2+ ions of the 1:1 stoichiometry demonstrated that the studied dendrimers formed stronger complexes with anionic DMPG. Both phospholipids have higher affinity towards dendrimers with a more compact structure. Higher differences in CID energy necessary for dissociation of 50% of the complex formed by dendrimers with DMPG vs. DMPC (DCID50) correlate with a lower hemotoxicity. Mass spectrometry results suggest that for a particular group of compounds the DCID50 might be one of the important factors explaining selectivity of antimicrobial peptides and their branched analogs targeting the bacterial membrane. Both circular dichroism and mass spectrometry studies demonstrated that dendrimers of Nα- and Nε-series possess a different conformation in solution and different affinity to model phospholipids, what might influence their specific microbicidal mechanism. Full article
(This article belongs to the Special Issue Dendrimers in Medicine and Biotechnology)
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Open AccessArticle Application of Reductive 13C-Methylation of Lysines to Enhance the Sensitivity of Conventional NMR Methods
Molecules 2013, 18(6), 7103-7119; https://doi.org/10.3390/molecules18067103
Received: 20 May 2013 / Revised: 13 June 2013 / Accepted: 14 June 2013 / Published: 18 June 2013
Cited by 13 | Viewed by 2957 | PDF Full-text (1489 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
NMR is commonly used to investigate macromolecular interactions. However, sensitivity problems hamper its use for studying such interactions at low physiologically relevant concentrations. At high concentrations, proteins or peptides tend to aggregate. In order to overcome this problem, we make use of reductive
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NMR is commonly used to investigate macromolecular interactions. However, sensitivity problems hamper its use for studying such interactions at low physiologically relevant concentrations. At high concentrations, proteins or peptides tend to aggregate. In order to overcome this problem, we make use of reductive 13C-methylation to study protein interactions at low micromolar concentrations. Methyl groups in dimethyl lysines are degenerate with one 13CH3 signal arising from two carbons and six protons, as compared to one carbon and three protons in aliphatic amino acids. The improved sensitivity allows us to study protein-protein or protein-peptide interactions at very low micromolar concentrations. We demonstrate the utility of this method by studying the interaction between the post-translationally lipidated hypervariable region of a human proto-oncogenic GTPase K-Ras and a calcium sensor protein calmodulin. Calmodulin specifically binds K-Ras and modulates its downstream signaling. This binding specificity is attributed to the unique lipidated hypervariable region of K-Ras. At low micromolar concentrations, the post-translationally modified hypervariable region of K-Ras aggregates and binds calmodulin in a non-specific manner, hence conventional NMR techniques cannot be used for studying this interaction, however, upon reductively methylating the lysines of calmodulin, we detected signals of the lipidated hypervariable region of K-Ras at physiologically relevant nanomolar concentrations. Thus, we utilize 13C-reductive methylation of lysines to enhance the sensitivity of conventional NMR methods for studying protein interactions at low concentrations. Full article
(This article belongs to the Special Issue NMR of Proteins and Small Biomolecules)
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Open AccessArticle New Resveratrol Oligomer Derivatives from the Roots of Rheum lhasaense
Molecules 2013, 18(6), 7093-7102; https://doi.org/10.3390/molecules18067093
Received: 27 May 2013 / Revised: 10 June 2013 / Accepted: 13 June 2013 / Published: 18 June 2013
Cited by 9 | Viewed by 2834 | PDF Full-text (270 KB) | HTML Full-text | XML Full-text
Abstract
Two new resveratrol trimer derivatives, named rheumlhasol A (1) and rheumlhasol B (2) were isolated from the methanolic extract of roots of Rheum lhasaense A. J. Li et P. K. Hsiao together with four known resveratrol dimer derivatives, including
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Two new resveratrol trimer derivatives, named rheumlhasol A (1) and rheumlhasol B (2) were isolated from the methanolic extract of roots of Rheum lhasaense A. J. Li et P. K. Hsiao together with four known resveratrol dimer derivatives, including maximol A (3), gnetin C (4), e-viniferin (5), and pallidol (6). The structures were determined by combined spectroscopic methods and by comparison of their spectral data with those reported in the literature. All the compounds isolated from R. lhasaense were tested for their ability to scavenge1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Full article
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Open AccessArticle Disperse Dyes Based on Aminothiophenes: Their Dyeing Applications on Polyester Fabrics and Their Antimicrobial Activity
Molecules 2013, 18(6), 7081-7092; https://doi.org/10.3390/molecules18067081
Received: 31 May 2013 / Revised: 13 June 2013 / Accepted: 14 June 2013 / Published: 18 June 2013
Cited by 8 | Viewed by 2501 | PDF Full-text (1115 KB) | HTML Full-text | XML Full-text
Abstract
A series of monoazo disperse dyes derived from arylazothienopyridazines were synthesized. Fastness properties of dyed polyester samples were measured. Most of the dyed fabrics tested displayed excellent washing and perspiration fastness and moderate light fastness. Finally, the biological activity of the synthesized dyes
[...] Read more.
A series of monoazo disperse dyes derived from arylazothienopyridazines were synthesized. Fastness properties of dyed polyester samples were measured. Most of the dyed fabrics tested displayed excellent washing and perspiration fastness and moderate light fastness. Finally, the biological activity of the synthesized dyes against Gram positive bacteria, Gram negative bacteria and yeast were evaluated. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Vortex-Induced Alignment of a Water Soluble Supramolecular Nanofiber Composed of an Amphiphilic Dendrimer
Molecules 2013, 18(6), 7071-7080; https://doi.org/10.3390/molecules18067071
Received: 14 May 2013 / Revised: 7 June 2013 / Accepted: 8 June 2013 / Published: 17 June 2013
Cited by 6 | Viewed by 2721 | PDF Full-text (511 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
We have synthesized a novel amphiphilic naphthalene imide bearing a cationic dendrimer wedge (NID). NID molecules in water self-assemble to form a two-dimensional ribbon, which further coils to give a linear supramolecular nanofiber. The sample solution showed linear dichroism (LD) upon stirring of
[...] Read more.
We have synthesized a novel amphiphilic naphthalene imide bearing a cationic dendrimer wedge (NID). NID molecules in water self-assemble to form a two-dimensional ribbon, which further coils to give a linear supramolecular nanofiber. The sample solution showed linear dichroism (LD) upon stirring of the solution, where NID nanofibers dominantly align at the center of vortex by hydrodynamic interaction with the downward torsional flows. Full article
(This article belongs to the Special Issue Dendrimers in Medicine and Biotechnology)
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Open AccessArticle The Skin Secretion of the Amphibian Phyllomedusa nordestina: A Source of Antimicrobial and Antiprotozoal Peptides
Molecules 2013, 18(6), 7058-7070; https://doi.org/10.3390/molecules18067058
Received: 6 May 2013 / Revised: 6 June 2013 / Accepted: 7 June 2013 / Published: 17 June 2013
Cited by 12 | Viewed by 3240 | PDF Full-text (694 KB) | HTML Full-text | XML Full-text
Abstract
Antimicrobial peptides (AMPs) from the dermaseptin and phylloseptin families were isolated from the skin secretion of Phyllomedusa nordestina, a recently described amphibian species from Northeastern Brazil. One dermaseptin and three phylloseptins were chosen for solid phase peptide synthesis. The antiprotozoal and antimicrobial
[...] Read more.
Antimicrobial peptides (AMPs) from the dermaseptin and phylloseptin families were isolated from the skin secretion of Phyllomedusa nordestina, a recently described amphibian species from Northeastern Brazil. One dermaseptin and three phylloseptins were chosen for solid phase peptide synthesis. The antiprotozoal and antimicrobial activities of the synthetic peptides were determined, as well as their cytotoxicity in mouse peritoneal cells. AMPs are being considered as frameworks for the development of novel drugs inspired by their mechanism of action. Full article
(This article belongs to the Section Molecular Diversity)
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Open AccessArticle Mirror-Symmetry-Breaking in Poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-biphenyl] (PF8P2) is Susceptible to Terpene Chirality, Achiral Solvents, and Mechanical Stirring
Molecules 2013, 18(6), 7035-7057; https://doi.org/10.3390/molecules18067035
Received: 13 May 2013 / Revised: 3 June 2013 / Accepted: 3 June 2013 / Published: 17 June 2013
Cited by 13 | Viewed by 3944 | PDF Full-text (2464 KB) | HTML Full-text | XML Full-text
Abstract
Solvent chirality transfer of (S)-/(R)-limonenes allows the instant generation of optically active PF8P2 aggregates with distinct circular dichroism (CD)/circularly polarized luminescence (CPL) amplitudes with a high quantum yield of 16–20%. The present paper also reports subtle mirror-symmetry-breaking effects in
[...] Read more.
Solvent chirality transfer of (S)-/(R)-limonenes allows the instant generation of optically active PF8P2 aggregates with distinct circular dichroism (CD)/circularly polarized luminescence (CPL) amplitudes with a high quantum yield of 16–20%. The present paper also reports subtle mirror-symmetry-breaking effects in CD-/CPL-amplitude and sign, CD/UV-vis spectral wavelengths, and photodynamics of the aggregates, though the reasons for the anomaly are unsolved. However, these photophysical properties depend on (i) the chemical natures of chiral and achiral molecules when used in solvent quantity, (ii) clockwise and counterclockwise stirring operations, and (iii) the order of addition of limonene and methanol to the chloroform solution. Full article
(This article belongs to the Special Issue Asymmetric Catalysis)
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Open AccessArticle A Soft Coral Natural Product, 11-Episinulariolide Acetate, Inhibits Gene Expression of Cyclooxygenase-2 and Interleukin-8 through Attenuation of Calcium Signaling
Molecules 2013, 18(6), 7023-7034; https://doi.org/10.3390/molecules18067023
Received: 22 April 2013 / Revised: 30 May 2013 / Accepted: 13 June 2013 / Published: 17 June 2013
Cited by 8 | Viewed by 3359 | PDF Full-text (765 KB) | HTML Full-text | XML Full-text
Abstract
Epidermal growth factor receptor (EGFR) is overexpressed in many types of cancer cells. EGFR-mediated signaling involves inflammatory gene expression including cyclooxygenase (COX)-2 and interleukin (IL)-8, and is associated with cancer pathogenesis. In a search of phytochemicals with anti-inflammatory activity, the COX-2 and IL-8
[...] Read more.
Epidermal growth factor receptor (EGFR) is overexpressed in many types of cancer cells. EGFR-mediated signaling involves inflammatory gene expression including cyclooxygenase (COX)-2 and interleukin (IL)-8, and is associated with cancer pathogenesis. In a search of phytochemicals with anti-inflammatory activity, the COX-2 and IL-8 inhibitory activities of some marine compounds were examined. After screening these compounds 11-episinulariolide acetate (1) from soft coral exhibited the most potent activity. Reverse-transcription PCR; western blotting; ELISA and luciferase assays were used to test the effect of compound 1 on EGF-stimulated expressions of COX-2 and IL-8 in A431 human epidermoid carcinoma cells. After exposure to 10 μM of compound 1, expression levels of COX-2 and IL-8 were reduced. In addition; intracellular Ca2+ increase and Ca2+-dependent transcription factor activation were blocked by compound 1. Thus, compound 1 can potentially serve as a lead compound for targeting Ca2+ signaling-dependent inflammatory diseases. Full article
(This article belongs to the Special Issue Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry)
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Open AccessArticle Optimal Binary Solvent Extraction System for Phenolic Antioxidants from Mengkudu (Morinda citrifolia) Fruit
Molecules 2013, 18(6), 7004-7022; https://doi.org/10.3390/molecules18067004
Received: 24 April 2013 / Revised: 26 May 2013 / Accepted: 9 June 2013 / Published: 14 June 2013
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Abstract
Antioxidants have been widely used in the food industry to enhance product quality by preventing oxidation of susceptible substances. This work was carried out to maximise the recovery of total phenolic content (TPC), total flavonoid content (TFC), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging capacity and
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Antioxidants have been widely used in the food industry to enhance product quality by preventing oxidation of susceptible substances. This work was carried out to maximise the recovery of total phenolic content (TPC), total flavonoid content (TFC), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging capacity and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity from Morinda citrifolia fruit via modification of the ethanol concentration, extraction time and extraction temperature at minimal processing cost. The optimised conditions yielded values of 881.57 ± 17.74 mg GAE/100 g DW for TPC, 552.53 ± 34.16 mg CE/100 g DW for TFC, 799.20 ± 2.97 µmol TEAC/100 g DW for ABTS and 2,317.01 ± 18.13 µmol TEAC/100 g DW for DPPH were 75% ethanol, 40 min of time and 57 °C. The four responses did not differ significantly (p > 0.05) from predicted values, indicating that models obtained are suitable to the optimisation of extraction conditions for phenolics from M. citrifolia. The relative amounts of flavonoids were 0.784 ± 0.01 mg quercetin/g of extract and 1.021 ± 0.04 mg rutin/g of extract. On the basis of the results obtained, M. citrifolia extract can be used as a valuable bioactive source of natural antioxidants. Full article
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Open AccessArticle N6-Benzyladenosine Derivatives as Novel N-Donor Ligands of Platinum(II) Dichlorido Complexes
Molecules 2013, 18(6), 6990-7003; https://doi.org/10.3390/molecules18066990
Received: 3 May 2013 / Revised: 7 June 2013 / Accepted: 8 June 2013 / Published: 14 June 2013
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Abstract
The platinum(II) complexes trans-[PtCl2(Ln)2]∙xSolv 113 (Solv = H2O or CH3OH), involving N6-benzyladenosine-based N-donor ligands, were synthesized; Ln stands for N6-(2-methoxybenzyl)adenosine (L1, involved in complex
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The platinum(II) complexes trans-[PtCl2(Ln)2]∙xSolv 113 (Solv = H2O or CH3OH), involving N6-benzyladenosine-based N-donor ligands, were synthesized; Ln stands for N6-(2-methoxybenzyl)adenosine (L1, involved in complex 1), N6-(4-methoxy-benzyl)adenosine (L2, 2), N6-(2-chlorobenzyl)adenosine (L3, 3), N6-(4-chlorobenzyl)-adenosine (L4, 4), N6-(2-hydroxybenzyl)adenosine (L5, 5), N6-(3-hydroxybenzyl)-adenosine (L6, 6), N6-(2-hydroxy-3-methoxybenzyl)adenosine (L7, 7), N6-(4-fluoro-benzyl)adenosine (L8, 8), N6-(4-methylbenzyl)adenosine (L9, 9), 2-chloro-N6-(3-hydroxy-benzyl)adenosine (L10, 10), 2-chloro-N6-(4-hydroxybenzyl)adenosine (L11, 11), 2-chloro-N6-(2-hydroxy-3-methoxybenzyl)adenosine (L12, 12) and 2-chloro-N6-(2-hydroxy-5-methylbenzyl)adenosine (L13, 13). The compounds were characterized by elemental analysis, mass spectrometry, IR and multinuclear (1H-, 13C-, 195Pt- and 15N-) and two-dimensional NMR spectroscopy, which proved the N7-coordination mode of the appropriate N6-benzyladenosine derivative and trans-geometry of the title complexes. The complexes 113 were found to be non-toxic in vitro against two selected human cancer cell lines (HOS and MCF7; with IC50 > 50.0 µM). However, they were found (by ESI-MS study) to be able to interact with the physiological levels of the sulfur-containing biogenic biomolecule L-methionine by a relatively simple 1:1 exchange mechanism (one Ln molecule was replaced by one L-methionine molecule), thus forming a mixed-nitrogen/sulfur-ligand dichlorido-platinum(II) coordination species. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessReview Diels-Alder Reactions of 12-Hydroxy-9(10®20)-5aH-abeo-abieta-1(10),8(9),12(13)-triene-11,14-dione
Molecules 2013, 18(6), 6969-6989; https://doi.org/10.3390/molecules18066969
Received: 1 March 2013 / Revised: 14 May 2013 / Accepted: 30 May 2013 / Published: 14 June 2013
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Abstract
12-Hydroxy-9(10®20)-5aH-abeo-abieta-1(10),8(9),12(13)-triene-11,14-dione (quinone 2) served as the dienophile in numerous intermolecular Diels-Alder reactions. These cycloadditions were conducted either thermally (including microwave heating) or with Lewis acid activation. While most dienes reacted with quinone 2 in good chemical yield, others were incompatible under the
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12-Hydroxy-9(10®20)-5aH-abeo-abieta-1(10),8(9),12(13)-triene-11,14-dione (quinone 2) served as the dienophile in numerous intermolecular Diels-Alder reactions. These cycloadditions were conducted either thermally (including microwave heating) or with Lewis acid activation. While most dienes reacted with quinone 2 in good chemical yield, others were incompatible under the experimental conditions used. Full article
(This article belongs to the Special Issue Diels-Alder Reaction)
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Open AccessReview Novel Biological Activities of Allosamidins
Molecules 2013, 18(6), 6952-6968; https://doi.org/10.3390/molecules18066952
Received: 26 April 2013 / Revised: 27 May 2013 / Accepted: 7 June 2013 / Published: 13 June 2013
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Abstract
Allosamidins, which are secondary metabolites of the Streptomyces species, have chitin-mimic pseudotrisaccharide structures. They bind to catalytic centers of all family 18 chitinases and inhibit their enzymatic activity. Allosamidins have been used as chitinase inhibitors to investigate the physiological roles of chitinases in
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Allosamidins, which are secondary metabolites of the Streptomyces species, have chitin-mimic pseudotrisaccharide structures. They bind to catalytic centers of all family 18 chitinases and inhibit their enzymatic activity. Allosamidins have been used as chitinase inhibitors to investigate the physiological roles of chitinases in a variety of organisms. Two prominent biological activities of allosamidins were discovered, where one has anti-asthmatic activity in mammals, while the other has the chitinase-production- promoting activity in allosamidin-producing Streptomyces. In this article, recent studies on the novel biological activities of allosamidins are reviewed. Full article
(This article belongs to the Special Issue Chitins and Chitosans)
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Open AccessReview Natural 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (Furaneol®)
Molecules 2013, 18(6), 6936-6951; https://doi.org/10.3390/molecules18066936
Received: 25 April 2013 / Revised: 6 June 2013 / Accepted: 7 June 2013 / Published: 13 June 2013
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Abstract
4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF, furaneol®) and its methyl ether 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF) are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In
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4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF, furaneol®) and its methyl ether 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF) are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In fruits 2,5-dimethyl-3(2H)-furanones are synthesized by a series of enzymatic steps whereas HDMF is also a product of the Maillard reaction. Numerous methods for the synthetic preparation of these compounds have been published and are applied by industry, but for the development of a biotechnological process the knowledge and availability of biosynthetic enzymes are required. During the last years substantial progress has been made in the elucidation of the biological pathway leading to HDMF and DMMF. This review summarizes the latest advances in this field. Full article
(This article belongs to the Special Issue Flavors and Fragrances)
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Open AccessArticle Application of a Rapid and Efficient Quantitative Analysis Method for Traditional Chinese Medicines: The Case Study of Quality Assessment of Salvia miltiorrhiza Bunge
Molecules 2013, 18(6), 6919-6935; https://doi.org/10.3390/molecules18066919
Received: 2 May 2013 / Revised: 30 May 2013 / Accepted: 7 June 2013 / Published: 13 June 2013
Cited by 7 | Viewed by 2917 | PDF Full-text (396 KB) | HTML Full-text | XML Full-text
Abstract
A reference extractive, containing multiple active known compounds, has been considered to be an alternative to individual reference standards. However, in the Chinese Pharmacopoeia (ChP) the great majority of reference extractives have been primarily used for qualitative identification by thin-layer chromatography (TLC) and
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A reference extractive, containing multiple active known compounds, has been considered to be an alternative to individual reference standards. However, in the Chinese Pharmacopoeia (ChP) the great majority of reference extractives have been primarily used for qualitative identification by thin-layer chromatography (TLC) and few studies on the applicability of reference extractives for quantitative analysis have been presented. Using Salvia miltiorrhiza Bunge as an example in this paper, we first present a preliminary discussion on the feasibility and applicability of reference extractives for the quantitative analysis of TCMs. The reference extractive of S. miltiorrhiza Bunge, comprised of three pharmacological marker compounds, namely cryptotanshinone, tanshinone I and tanshinone IIA, was prepared from purchased Salvia miltiorrhiza Bunge by extraction with acetone under reflux, followed by silica gel column chromatography with stepwise elution with petroleum ether-ethyl acetate (25:1, v/v, 4.5 BV) to remove the non-target components and chloroform-methanol (10:1, v/v; 3 BV) to yield a crude reference extractive solution. After concentration, the solution was further purified by preparative reversed-phase HPLC on a C18 column with isocratic elution with 77% methanol aqueous solution to yield the total reference extractive of S. miltiorrhiza Bunge. Thereafter, the reference extractive was applied to the quality assessment of S. miltiorrhiza Bunge using high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD). The validation of the method, including linearity, sensitivity, repeatability, stability and recovery testing, indicated that this method was valid, reliable and sensitive, with good reproducibility. The developed method was successfully applied to quantify seven batches of samples collected from different regions in China and the results were also similar to those obtained using reference standards, with relative standard deviation (RSD) <3%. Preparation of a reference extractive of S. miltiorrhiza Bunge was significantly less expensive and time consuming than preparation of a corresponding reference standard. Quantitative analysis using a reference extractive was shown to be simple, low-cost, time-saving and practical, with high sensitivity and good stability; and is, therefore, a strong alternative to the use of reference standards. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Preliminary Biological Evaluation of Novel 99mTc-Cys-Annexin A5 as a Apoptosis Imaging Agent
Molecules 2013, 18(6), 6908-6918; https://doi.org/10.3390/molecules18066908
Received: 15 May 2013 / Revised: 24 May 2013 / Accepted: 5 June 2013 / Published: 10 June 2013
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Abstract
A novel annexin A5 derivative (cys-annexin A5) with a single cysteine residue at its C-terminal has been developed and successfully labeled in high labeling yield with 99mTc by a ligand exchange reaction. Like the 1st generation 99mTc-HYNIC-annexin A5, the novel 99m
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A novel annexin A5 derivative (cys-annexin A5) with a single cysteine residue at its C-terminal has been developed and successfully labeled in high labeling yield with 99mTc by a ligand exchange reaction. Like the 1st generation 99mTc-HYNIC-annexin A5, the novel 99mTc-cys-annexin A5 derivative shows in normal mice mainly renal and, to a lesser extent, hepatobiliary excretion. In rat models of hepatic apoptosis there was 283% increase in hepatic uptake of 99mTc-cys-annexin A5 as compared to normal mice. The results indicate that the novel 99mTc-cys-annexin A5 is a potential apoptosis imaging agent. Full article
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Open AccessArticle Dihydrochalcones with Antiinflammatory Activity from Leaves and Twigs of Cyathostemma argenteum
Molecules 2013, 18(6), 6898-6907; https://doi.org/10.3390/molecules18066898
Received: 8 May 2013 / Revised: 30 May 2013 / Accepted: 7 June 2013 / Published: 10 June 2013
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Abstract
A new dihydrochalcone derivative, 4',6'-dihydroxy-2',4-dimethoxy-5'-(2''-hydroxybenzyl)dihydrochalcone (1) and one known dihydrochalcone, 4',6'-dihydroxy-2',4- dimethoxydihydrochalcone (2) were isolated from leaves and twigs of Cyathostemma argenteum. Their structures were established by spectral methods, mainly 2D NMR spectroscopic techniques, which involved combined applications
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A new dihydrochalcone derivative, 4',6'-dihydroxy-2',4-dimethoxy-5'-(2''-hydroxybenzyl)dihydrochalcone (1) and one known dihydrochalcone, 4',6'-dihydroxy-2',4- dimethoxydihydrochalcone (2) were isolated from leaves and twigs of Cyathostemma argenteum. Their structures were established by spectral methods, mainly 2D NMR spectroscopic techniques, which involved combined applications of DEPT, COSY, HMQC and HMBC. The molecular structure of 1 was also confirmed by single crystal X-ray diffraction. The test compounds 1 and 2 displayed significant inhibitory activity at a dose of 1 mg/ear on edema formation at all determination times, with similar intensity as phenylbutazone. Full article
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Open AccessArticle Arylsulfonylamino-Benzanilides as Inhibitors of the Apical Sodium-Dependent Bile Salt Transporter (SLC10A2)
Molecules 2013, 18(6), 6883-6897; https://doi.org/10.3390/molecules18066883
Received: 2 May 2013 / Revised: 4 June 2013 / Accepted: 5 June 2013 / Published: 10 June 2013
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Abstract
The apical sodium-dependent bile salt transporter (ASBT) plays a pivotal role in maintaining bile acid homeostasis. Inhibition of ASBT would reduce bile acid pool size and lower cholesterol levels. In this report, a series of novel arylsulfonylaminobenzanilides were designed and synthesized as potential
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The apical sodium-dependent bile salt transporter (ASBT) plays a pivotal role in maintaining bile acid homeostasis. Inhibition of ASBT would reduce bile acid pool size and lower cholesterol levels. In this report, a series of novel arylsulfonylaminobenzanilides were designed and synthesized as potential inhibitors of ASBT. Most of them demonstrated great potency against ASBT’s bile acid transport activity. In particular, compound 5g2 inhibited ASBT activity with an IC50 value of 0.11 μM. These compounds represent potential cholesterol-lowering drugs. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Design, Synthesis and Evaluation of the Antibacterial Enhancement Activities of Amino Dihydroartemisinin Derivatives
Molecules 2013, 18(6), 6866-6882; https://doi.org/10.3390/molecules18066866
Received: 14 May 2013 / Revised: 29 May 2013 / Accepted: 30 May 2013 / Published: 10 June 2013
Cited by 12 | Viewed by 3147 | PDF Full-text (736 KB) | HTML Full-text | XML Full-text
Abstract
Artemisinin (ART) and its derivatives artesunate (AS), dihydroartemisinin (DHA) are a group of drugs containing a sesquiterpene lactone used to treat malaria. Previously, AS was shown to not have antibacterial activity but to significantly increase the antibacterial activities of β-lactam antibiotics against E.
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Artemisinin (ART) and its derivatives artesunate (AS), dihydroartemisinin (DHA) are a group of drugs containing a sesquiterpene lactone used to treat malaria. Previously, AS was shown to not have antibacterial activity but to significantly increase the antibacterial activities of β-lactam antibiotics against E. coli. Herein, molecular docking experiments showed that ART, AS and DHA could dock into AcrB very well, especially DHA and AS; both DHA and AS had the same docking pose. The affinity between AS and AcrB seemed weaker than that of DHA, while the succinate tail of AS, which was like a “bug”, could extend in the binding pocket very well. Imitating the parent nucleus of DHA and the succinate tail of AS, twenty-one DHA derivatives 4au were designed and synthesized. Among them, seventeen were new compounds. The synergistic effects against E. coli AG100A/pET28a-AcrB showed among the new structures 4k, 4l, 4m, 4n, and 4r exhibited significant synergism with β-lactam antibiotics although they had no direct antibacterial activities themelves. The bacterial growth assay showed that only 4k in combination with ampicillin or cefuroxime could totally inhibit bacterial growth from 0 to 12 h, demonstrating that 4k had the best antibacterial enhancement effect. In conclusion, our results provided a new idea and several candidate compounds for antibacterial activity enhancers against multidrug resistant E. coli. Full article
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Open AccessArticle Application and Analysis of the Folin Ciocalteu Method for the Determination of the Total Phenolic Content from Limonium Brasiliense L.
Molecules 2013, 18(6), 6852-6865; https://doi.org/10.3390/molecules18066852
Received: 1 April 2013 / Revised: 1 June 2013 / Accepted: 6 June 2013 / Published: 10 June 2013
Cited by 134 | Viewed by 9580 | PDF Full-text (313 KB) | HTML Full-text | XML Full-text
Abstract
Limonium brasiliense is a common plant on the southern coast of Brazil. The roots are traditionally used for treatment of premenstrual syndrome, menstrual disturbances and genito-urinary infections. Pharmaceutical preparations obtained from its roots and used for these purposes were marketed in Brazil in
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Limonium brasiliense is a common plant on the southern coast of Brazil. The roots are traditionally used for treatment of premenstrual syndrome, menstrual disturbances and genito-urinary infections. Pharmaceutical preparations obtained from its roots and used for these purposes were marketed in Brazil in the 1980s and 1990s. Currently, the Brazilian Drug Agency (National Health Surveillance Agency, ANVISA) has canceled the registration of these products, and their use was discontinued because of a lack of studies to characterize the plant raw material and ensure the effectiveness and safety of its use. The aim of the present study was to develop and validate an analytical method to determine the content of total polyphenols (TP) in an extract from L. brasiliense roots, by the UV/Vis spectrophotometric method. L. brasiliense roots were extracted in acetone:water (7:3, v/v-10% w/v). The crude extract was used to develop a method for TP assay. The method was validated according to national and international guidelines. The optimum conditions for analysis time, wavelength, and standard substance were 30 min, 760 nm, and pyrogallol, respectively. Under these conditions, validation by UV/Vis spectrophotometry proved the method to be linear, specific, precise, accurate, reproducible, robust, and easy to perform. This methodology complies with the requirements for analytical application and to ensure the reliability of the results. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Exploring the C-X…π Halogen Bonding Motif: An Infrared and Raman Study of the Complexes of CF3X (X = Cl, Br and I) with the Aromatic Model Compounds Benzene and Toluene
Molecules 2013, 18(6), 6829-6851; https://doi.org/10.3390/molecules18066829
Received: 23 April 2013 / Revised: 29 May 2013 / Accepted: 31 May 2013 / Published: 10 June 2013
Cited by 34 | Viewed by 3173 | PDF Full-text (450 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The formation of halogen bonded complexes formed between the trifluorohalomethanes CF3Cl, CF3Br and CF3I and the Lewis bases benzene and toluene at temperatures below 150K was investigated using FTIR and Raman spectroscopy. Experiments using liquid krypton as
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The formation of halogen bonded complexes formed between the trifluorohalomethanes CF3Cl, CF3Br and CF3I and the Lewis bases benzene and toluene at temperatures below 150K was investigated using FTIR and Raman spectroscopy. Experiments using liquid krypton as solvent show that for both CF3Br and CF3I substantial fractions of the monomers can be involved in 1:1 complexes. In addition, weak absorptions illustrating the formation of 2:1 complexes between CF3I and benzene are observed. Using spectra recorded at temperatures between 120 and 140 K, observed information on the relative stability was obtained for all complexes by determining the complexation enthalpies in solution. The resulting values for CF3Br.benzene, CF3I.benzene and (CF3I)2.benzene are −6.5(3), −7.6(2) and −14.5(9) kJ mol−1. The values for CF3Br.toluene and CF3I.toluene are −6.2(5) and −7.4(5) kJ mol−1. The experimental complexation enthalpies are compared with theoretical data obtained by combining results from MP2/aug-cc-pVDZ(-PP) and MP2/aug-cc-pVTZ(-PP) ab initio calculations, from statistical thermodynamical calculations and from Monte Carlo Free Energy Perturbation simulations. The data are also compared with results derived for other C-X···π halogen bonded complexes involving unsaturated Lewis bases such as ethene and ethyne. Full article
(This article belongs to the Special Issue Halogen Bond: Application and Prospect)
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