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Molecules, Volume 16, Issue 5 (May 2011), Pages 3456-4327

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Open AccessArticle Reassignment of the Structures of Products Produced by Reactions of the Product Believed To Be 2-(1-Phenyl-2-Thiocyanatoethylidene)-malononitrile with Electrophiles
Molecules 2011, 16(5), 3456-3468; doi:10.3390/molecules16053456
Received: 1 April 2011 / Revised: 15 April 2011 / Accepted: 18 April 2011 / Published: 26 April 2011
Cited by 4 | PDF Full-text (157 KB)
Abstract The reactivity of the product believed to be 2-(1-phenyl-2-thiocyanato-ethylidene)malononitrile toward a variety of electrophilic and nucleophilic reagents is reported. Full article
Open AccessArticle Thiophene Derivatives with Antileishmanial Activity Isolated from Aerial Parts of Porophyllum ruderale (Jacq.) Cass.
Molecules 2011, 16(5), 3469-3478; doi:10.3390/molecules16053469
Received: 21 February 2011 / Revised: 22 March 2011 / Accepted: 20 April 2011 / Published: 26 April 2011
Cited by 16 | PDF Full-text (129 KB)
Abstract
Porophyllum ruderale (Jacq.) Cass. is a plant native to Brazil and in the northwest region of the state of Paraná, Brazil, aerial parts of P. ruderale have been used popularly in the treatment of lesions caused by Leishmania sp.. In this study
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Porophyllum ruderale (Jacq.) Cass. is a plant native to Brazil and in the northwest region of the state of Paraná, Brazil, aerial parts of P. ruderale have been used popularly in the treatment of lesions caused by Leishmania sp.. In this study the antileishmanial and cytotoxic activities of the crude extract, fractions, and isolated compounds from aerial parts of P. ruderale was evaluated. The dichloromethane extract was submitted to chromatography to yield compounds active against Leishmania amazonensis. Their structures were established by comparison of their spectroscopic data with literature values. The activities of crude extract against promastigote and axenic amastigote forms of L. amazonensis (IC50) were 60.3 and 77.7 μg/mL, respectively. Its cytotoxic activity against macrophage cells (CC50) was 500 μg/mL. The thiophene derivatives isolated were: 5-methyl-2,2':5',2"-terthiophene (compound A) and 5'-methyl–[5–(4–acetoxy-1–butynyl)]–2,2'-bithiophene (compound B). The activity of compound A against promastigote and axenic amastigote forms were 7.7 and 19.0 μg/mL and of compound B were 21.3 and 28.7 μg/mL, respectively. The activity of the isolated compounds against promastigote and axenic amastigote forms was better than that of the crude extract and more selective against protozoa than for macrophage cells. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Study of the Biological Activity of Novel Synthetic Compounds with Antiviral Properties against Human Rhinoviruses
Molecules 2011, 16(5), 3479-3487; doi:10.3390/molecules16053479
Received: 9 February 2011 / Revised: 6 April 2011 / Accepted: 20 April 2011 / Published: 26 April 2011
Cited by 5 | PDF Full-text (246 KB)
Abstract
Picornaviridae represent a very large family of small RNA viruses, some of which are the cause of important human and animal diseases. Since no specific therapy against any of these viruses currently exists, palliative symptomatic treatments are employed. The early steps of the
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Picornaviridae represent a very large family of small RNA viruses, some of which are the cause of important human and animal diseases. Since no specific therapy against any of these viruses currently exists, palliative symptomatic treatments are employed. The early steps of the picornavirus replicative cycle seem to be privileged targets for some antiviral compounds like disoxaril and pirodavir. Pirodavir’s main weakness is its cytotoxicity on cell cultures at relatively low doses. In this work some original synthetic compounds were tested, in order to find less toxic compounds with an improved protection index (PI) on infected cells. Using an amino group to substitute the oxygen atom in the central chain, such as that in the control molecule pirodavir, resulted in decreased activity against Rhinoviruses and Polioviruses. The presence of an -ethoxy-propoxy- group in the central chain (as in compound I-6602) resulted in decreased cell toxicity and in improved anti-Rhinovirus activity. This compound actually showed a PI >700 on HRV14, while pirodavir had a PI of 250. These results demonstrate that modification of pirodavir’s central hydrocarbon chain can lead to the production of novel derivatives with low cytotoxicity and improved PI against some strains of Rhinoviruses. Full article
(This article belongs to the collection Bioactive Compounds)
Open AccessArticle Synthesis, Singlet Oxygen Photogeneration and DNA Photocleavage of Porphyrins with Nitrogen Heterocycle Tails
Molecules 2011, 16(5), 3488-3498; doi:10.3390/molecules16053488
Received: 11 March 2011 / Revised: 13 April 2011 / Accepted: 18 April 2011 / Published: 26 April 2011
Cited by 11 | PDF Full-text (218 KB)
Abstract
Eight novel compounds were prepared by reaction of 5-(bromo- propoxyphenyl)-10,15,20-triphenylporphyrin with oxazole thiols, 1,3,4-oxadiazole thiols and 1,3,4-thiadiazole thiols, and their structures confirmed by UV-vis, IR, 1H-NMR, MS and elemental analysis. The assessment of indirectly measured 1O2 production rates against 5,10,15,20-tetraphenyl
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Eight novel compounds were prepared by reaction of 5-(bromo- propoxyphenyl)-10,15,20-triphenylporphyrin with oxazole thiols, 1,3,4-oxadiazole thiols and 1,3,4-thiadiazole thiols, and their structures confirmed by UV-vis, IR, 1H-NMR, MS and elemental analysis. The assessment of indirectly measured 1O2 production rates against 5,10,15,20-tetraphenyl porphyrin (H2TPP) were described and the relative singlet oxygen production yields were:porphyrin 5 > porphyrins 1, 3, 4, 6-8, H2TPP > porphyrin 2. Porphyrin 4 and porphyrin 7 showed substantial photocleavage activities toward DNA, with over 75% cleavage observed at 40 µM. It suggested that these those porphyrins with nitrogen heterocycle tails are potential photosensitive agents. Full article
Open AccessArticle Gombapyrones E and F, New α-Pyrone Polyenes Produced by Streptomyces sp. KMC-002
Molecules 2011, 16(5), 3519-3529; doi:10.3390/molecules16053519
Received: 29 March 2011 / Revised: 19 April 2011 / Accepted: 20 April 2011 / Published: 26 April 2011
Cited by 3 | PDF Full-text (299 KB)
Abstract
Microorganism-derived polyene polyketides have been shown to display a variety of biological activities and have attracted great interest due to their structurally intriguing chemical diversity. Two new polyenes were isolated from a culture broth of Streptomyces sp. KMC-002 obtained from a soil sample
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Microorganism-derived polyene polyketides have been shown to display a variety of biological activities and have attracted great interest due to their structurally intriguing chemical diversity. Two new polyenes were isolated from a culture broth of Streptomyces sp. KMC-002 obtained from a soil sample in an abandoned mine. The structures of these compounds were determined to be α-pyrone-containing polyene analogues through analyses of HRFABMS, UV and NMR data, and were named Gombapyrones E (1) and F (2). Gombapyrone E (1) showed antibacterial activity against Micrococcus luteus, Enterococcus hirae, Staphylococcus aureus and MRSA. Full article
(This article belongs to the collection Bioactive Compounds)
Open AccessArticle Effect of Lectins from Diocleinae Subtribe against Oral Streptococci
Molecules 2011, 16(5), 3530-3543; doi:10.3390/molecules16053530
Received: 30 March 2011 / Revised: 20 April 2011 / Accepted: 25 April 2011 / Published: 27 April 2011
Cited by 16 | PDF Full-text (778 KB)
Abstract
Surface colonization is an essential step in biofilm development. The ability of oral pathogens to adhere to tooth surfaces is directly linked with the presence of specific molecules at the bacterial surface that can interact with enamel acquired pellicle ligands. In light of
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Surface colonization is an essential step in biofilm development. The ability of oral pathogens to adhere to tooth surfaces is directly linked with the presence of specific molecules at the bacterial surface that can interact with enamel acquired pellicle ligands. In light of this, the aim of this study was to verify inhibitory and antibiofilm action of lectins from the Diocleinaesubtribe against Streptococcus mutans and Streptococcus oralis. The inhibitory action against planctonic cells was assessed using lectins from Canavaliaensi formis (ConA), Canavalia brasiliensis (ConBr), Canavalia maritima (ConM), Canavalia gladiata (CGL) and Canavalia boliviana (ConBol). ConBol, ConBr and ConM showed inhibitory activity on S. mutans growth. All lectins, except ConA, stimulated significantly the growth of S. oralis. To evaluate the effect on biofilm formation, clarified saliva was added to 96-well, flat-bottomed polystyrene plates, followed by the addition of solutions containing 100 or 200 µg/mL of the selected lectins. ConBol, ConM and ConA inhibited the S. mutans biofilms. No effects were found on S. oralis biofilms. Structure/function analysis were carried out using bioinformatics tools. The aperture and deepness of the CRD (Carbohydrate Recognition Domain) permit us to distinguish the two groups of Canavalia lectins in accordance to their actions against S. mutans and S. oralis. The results found provide a basis for encouraging the use of plant lectins as biotechnological tools in ecological control and prevention of caries disease. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Microwave-Assisted One-Step Synthesis of Fenamic Acid Hydrazides from the Corresponding Acids
Molecules 2011, 16(5), 3544-3551; doi:10.3390/molecules16053544
Received: 21 February 2011 / Revised: 30 March 2011 / Accepted: 2 April 2011 / Published: 28 April 2011
Cited by 10 | PDF Full-text (246 KB)
Abstract
A facile and efficient method for synthesis of fenamic acid hydrazides from their acids in one-step reaction under microwave irradiation and solvent-free conditions was developed. Compared with the two-step conventional heating method, the process was simple, the reaction time was very short and
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A facile and efficient method for synthesis of fenamic acid hydrazides from their acids in one-step reaction under microwave irradiation and solvent-free conditions was developed. Compared with the two-step conventional heating method, the process was simple, the reaction time was very short and the yields were almost quantitative. Full article
(This article belongs to the Section Organic Synthesis)
Open AccessArticle Diterpene Glycosides from Stevia rebaudiana
Molecules 2011, 16(5), 3552-3562; doi:10.3390/molecules16053552
Received: 24 March 2011 / Revised: 16 April 2011 / Accepted: 20 April 2011 / Published: 28 April 2011
Cited by 31 | PDF Full-text (278 KB)
Abstract
Three novel diterpene glycosides were isolated for the first time from the commercial extract of the leaves of Stevia rebaudiana, along with several known steviol glycosides, namely stevioside, rebaudiosides A-F, rubusoside and dulcoside A. The new compounds were identified as 13-[(2-O
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Three novel diterpene glycosides were isolated for the first time from the commercial extract of the leaves of Stevia rebaudiana, along with several known steviol glycosides, namely stevioside, rebaudiosides A-F, rubusoside and dulcoside A. The new compounds were identified as 13-[(2-O-β-D-glucopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-15-en-19-oic acid (1), 13-[(2-O-β-D-glucopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy]-16β-hydroxy-ent-kauran-19-oic acid (2) and 13-methyl-16-oxo-17-nor-ent-kauran-19-oic acid-β-D-glucopyranosyl ester (3) on the basis of extensive 2D NMR and MS spectroscopic data as well as chemical studies. Full article
(This article belongs to the Section Natural Products)
Open AccessCommunication Reduction of Nitroarenes to Azoxybenzenes by Potassium Borohydride in Water
Molecules 2011, 16(5), 3563-3568; doi:10.3390/molecules16053563
Received: 24 February 2011 / Revised: 15 April 2011 / Accepted: 22 April 2011 / Published: 28 April 2011
Cited by 6 | PDF Full-text (126 KB)
Abstract
The synthesis of the azoxybenzenes by the reduction of nitroarenes with reducing agent potassium borohydride in water was reported for the first time. PEG-400 was used as a phase transfer catalyst and could effectively catalyze the reduction. The electronic effects of substituent groups
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The synthesis of the azoxybenzenes by the reduction of nitroarenes with reducing agent potassium borohydride in water was reported for the first time. PEG-400 was used as a phase transfer catalyst and could effectively catalyze the reduction. The electronic effects of substituent groups play an important role in determining the reduction efficiencies. Electron-withdrawing substituents promote the formation of the azoxybenzene products, while electron-releasing groups retard the reductions to various degrees depending on the extent of their electron-donating ability. Full article
(This article belongs to the Section Organic Synthesis)
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Open AccessArticle Chromium (VI) Ion Adsorption Features of Chitosan Film and Its Chitosan/Zeolite Conjugate 13X Film
Molecules 2011, 16(5), 3569-3579; doi:10.3390/molecules16053569
Received: 20 January 2011 / Revised: 21 February 2011 / Accepted: 9 March 2011 / Published: 28 April 2011
Cited by 19 | PDF Full-text (389 KB)
Abstract
This research evaluated the importance of the adsorption properties of chitosan a chitosan/zeolite conjugate film for the removal of Cr(VI) ions from solutions in the 5–260 mg/L concentration range, when the pH was adjusted to 4.0 and 6.0. The uptake capacities of the
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This research evaluated the importance of the adsorption properties of chitosan a chitosan/zeolite conjugate film for the removal of Cr(VI) ions from solutions in the 5–260 mg/L concentration range, when the pH was adjusted to 4.0 and 6.0. The uptake capacities of the films formed by chitosan and by the chitosan/zeolite conjugate were calculated by mass balance. The equilibrium isotherms were fitted to the Langmuir, Freundlich and Redlich-Peterson models. The chitosan film seems to be a good sorbent for Cr(VI) at pH 4, but its physical instability suggests the need for a more resilient support. Due to this fact zeolite was added to the chitosan matrix in solution and a chitosan/zeolite (CS/Zeo) film was thus formed. The solubility of the film and the characterization of the different matrices by FTIR, TGA and X-Ray showed that a cross-linked structure was formed between the chitosan and zeolite and the solubility of the film increased. In this study, the low manufacturing cost of the CS/Zeo matrix, the good uptake of Cr(VI) at acidic pH (17.28 mg/g) and the non desorption of Cr(VI) from the film in water suggests this combination should be tested in industrial environment. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Synthesis of Some Phenylpropanoid Glycosides (PPGs) and Their Acetylcholinesterase/Xanthine Oxidase Inhibitory Activities
Molecules 2011, 16(5), 3580-3596; doi:10.3390/molecules16053580
Received: 16 March 2011 / Revised: 25 April 2011 / Accepted: 26 April 2011 / Published: 28 April 2011
Cited by 4 | PDF Full-text (343 KB)
Abstract
In this research, three categories of phenylpropanoid glycosides (PPGs) were designed and synthesized with PPGs isolated from Rhodiola rosea L. as lead compounds. Their inhibitory abilities toward acetylcholinesterase (AChE) and xanthine oxidase (XOD) were also tested. Some of the synthetic PPGs exhibited excellent
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In this research, three categories of phenylpropanoid glycosides (PPGs) were designed and synthesized with PPGs isolated from Rhodiola rosea L. as lead compounds. Their inhibitory abilities toward acetylcholinesterase (AChE) and xanthine oxidase (XOD) were also tested. Some of the synthetic PPGs exhibited excellent enzyme inhibitory abilities. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle Molecular Docking of Aromatase Inhibitors
Molecules 2011, 16(5), 3597-3617; doi:10.3390/molecules16053597
Received: 5 April 2011 / Accepted: 19 April 2011 / Published: 28 April 2011
Cited by 34 | PDF Full-text (2340 KB)
Abstract
Aromatase is an enzyme that plays a critical role in the development of estrogen receptor positive breast cancer. As aromatase catalyzes the aromatization of androstenedione to estrone, a naturally occurring estrogen, it is a promising drug target for therapeutic management. The undesirable effects
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Aromatase is an enzyme that plays a critical role in the development of estrogen receptor positive breast cancer. As aromatase catalyzes the aromatization of androstenedione to estrone, a naturally occurring estrogen, it is a promising drug target for therapeutic management. The undesirable effects found in aromatase inhibitors (AIs) that are in clinical use necessitate the discovery of novel AIs with higher selectivity, less toxicity and improving potency. In this study, we elucidate the binding mode of all three generations of AI drugs to the crystal structure of aromatase by means of molecular docking. It was demonstrated that the docking protocol could reliably reproduce the interaction of aromatase with its substrate with an RMSD of 1.350 Å. The docking study revealed that polar (D309, T310, S478 and M374), aromatic (F134, F221 and W224) and non-polar (A306, A307, V370, L372 and L477) residues were important for interacting with the AIs. The insights gained from the study herein have great potential for the design of novel AIs. Full article
Open AccessArticle Chiroptical Measurement of Chiral Aggregates at Liquid-Liquid Interface in Centrifugal Liquid Membrane Cell by Mueller Matrix and Conventional Circular Dichroism Methods
Molecules 2011, 16(5), 3636-3647; doi:10.3390/molecules16053636
Received: 21 March 2011 / Revised: 18 April 2011 / Accepted: 19 April 2011 / Published: 29 April 2011
Cited by 8 | PDF Full-text (304 KB)
Abstract
The centrifugal liquid membrane (CLM) cell has been utilized for chiroptical studies of liquid-liquid interfaces with a conventional circular dichroism (CD) spectropolarimeter. These studies required the characterization of optical properties of the rotating cylindrical CLM glass cell, which was used under the high
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The centrifugal liquid membrane (CLM) cell has been utilized for chiroptical studies of liquid-liquid interfaces with a conventional circular dichroism (CD) spectropolarimeter. These studies required the characterization of optical properties of the rotating cylindrical CLM glass cell, which was used under the high speed rotation. In the present study, we have measured the circular and linear dichroism (CD and LD) spectra and the circular and linear birefringence (CB and LB) spectra of the CLM cell itself as well as those of porphyrine aggregates formed at the liquid-liquid interface in the CLM cell, applying Mueller matrix measurement method. From the results, it was confirmed that the CLM-CD spectra of the interfacial porphyrin aggregates observed by a conventional CD spectropolarimeter should be correct irrespective of LD and LB signals in the CLM cell. Full article
(This article belongs to the Special Issue Chiroptical Techniques)
Open AccessArticle Diversity-Oriented Synthesis of a Library of Substituted Tetrahydropyrones Using Oxidative Carbon-Hydrogen Bond Activation and Click Chemistry
Molecules 2011, 16(5), 3648-3662; doi:10.3390/molecules16053648
Received: 9 March 2011 / Accepted: 12 April 2011 / Published: 2 May 2011
Cited by 2 | PDF Full-text (315 KB)
Abstract
Eighteen (2RS,6RS)-2-(4-methoxyphenyl)-6-(substituted ethyl)dihydro-2H-pyran-4(3H)ones were synthesized via a DDQ-mediated oxidative carbon-hydrogen bond activation reaction. Fourteen of these tetrahydropyrans were substituted with triazoles readily assembled via azide-alkyne click-chemistry reactions. Examples of a linked benzotriazole and pyrazole motif
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Eighteen (2RS,6RS)-2-(4-methoxyphenyl)-6-(substituted ethyl)dihydro-2H-pyran-4(3H)ones were synthesized via a DDQ-mediated oxidative carbon-hydrogen bond activation reaction. Fourteen of these tetrahydropyrans were substituted with triazoles readily assembled via azide-alkyne click-chemistry reactions. Examples of a linked benzotriazole and pyrazole motif were also prepared. To complement the structural diversity, the alcohol substrates were obtained from stereoselective reductions of the tetrahydropyrone. This library provides rapid access to structurally diverse non-natural compounds to be screened against a variety of biological targets. Full article
(This article belongs to the Special Issue Diversity Oriented Synthesis)
Open AccessArticle Cytotoxicity and Oral Acute Toxicity Studies of Lantana camara Leaf Extract
Molecules 2011, 16(5), 3663-3674; doi:10.3390/molecules16053663
Received: 14 March 2011 / Revised: 26 April 2011 / Accepted: 30 April 2011 / Published: 3 May 2011
Cited by 11 | PDF Full-text (678 KB)
Abstract
Background: The objective of this study was to investigate the toxicity of Lantana camara methanol extract. Methods: In order to evaluate the toxicity of Lantana camara, the acute toxicity of the methanolic extract on adult mice and cytotoxicity test on
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Background: The objective of this study was to investigate the toxicity of Lantana camara methanol extract. Methods: In order to evaluate the toxicity of Lantana camara, the acute toxicity of the methanolic extract on adult mice and cytotoxicity test on Vero cell line were investigated. A fixed large dose of 2 g/kg body weight of L. camara leaf extract was administrated by a single oral gavage according to the OECD procedure. Results: In 2 weeks, L. camara leaf extract showed no obvious acute toxicity. While female mice lost body weight after being treated with single dose of leaf extract in acute toxicity test, male ones lost organ mass, particularly for heart and kidney. The biochemical liver function tests showed significantly elevated TBIL and ALT in the L. camara leaf extract treated female mice group compared with the control group. Cytotoxicity effect of leaf extract of L. camara was estimated through a MTT assay. Cytotoxicity tests on Vero cell line disclosed that leaf extract at concentrations up to 500 µg/mL inhibited the growth of cells 2.5 times less than did Triton 100× 1%. More interestingly, the cytotoxicity initiated to decline at elevated concentrations of this extract. Conclusions: The results of both tests confirm that L. camara shows a pro toxic effect. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Inhibition of Inflammatory Mediators by Neobavaisoflavone in Activated RAW264.7 Macrophages
Molecules 2011, 16(5), 3701-3712; doi:10.3390/molecules16053701
Received: 9 March 2011 / Revised: 27 April 2011 / Accepted: 29 April 2011 / Published: 3 May 2011
Cited by 26 | PDF Full-text (229 KB)
Abstract
Flavonoids and coumarins are the major bioactive constituents identified in Psoralea corylifolia. The active fraction isolated from fruits, seeds and roots possesses antibacterial, antioxidative and immunomodulatory properties. Neobavaisoflavone is one of the flavonoids found in Psoralea corylifolia. In the present study we
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Flavonoids and coumarins are the major bioactive constituents identified in Psoralea corylifolia. The active fraction isolated from fruits, seeds and roots possesses antibacterial, antioxidative and immunomodulatory properties. Neobavaisoflavone is one of the flavonoids found in Psoralea corylifolia. In the present study we investigated in vitro the anti-inflammatory activity of neobavaisoflavone. Macrophages play an important role in inflammation through the release of inflammatory mediators involved in the immune response. Inappropriate and prolonged macrophage activation is largely responsible for the pathology of acute and chronic inflammatory conditions. Neobavaisoflavone significantly inhibited the production of reactive oxygen species (ROS), reactive nitrogen species (RNS) and cytokines: IL-1β, IL-6, IL-12p40, IL-12p70, TNF-α in LPS+IFN-γ– or PMA– stimulated RAW264.7 macrophages. Full article
(This article belongs to the collection Bioactive Compounds)
Open AccessArticle Simultaneous and Rapid Determination of Main Lignans in Different Parts of Schisandra Sphenanthera by Micellar Electrokinetic Capillary Chromatography
Molecules 2011, 16(5), 3713-3722; doi:10.3390/molecules16053713
Received: 7 April 2011 / Revised: 25 April 2011 / Accepted: 26 April 2011 / Published: 3 May 2011
Cited by 7 | PDF Full-text (115 KB)
Abstract
Lignans are imporant active ingredients of Schisandra sphenanthera. A micellar electrokinetic chromatography method was developed for the simultaneous determination of eight lignans – schizandrin, schisandrol B, schisantherin A, schisanhenol, anwulignan, deoxyschizandrin, schizandrin B and schizandrin C – in different parts of
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Lignans are imporant active ingredients of Schisandra sphenanthera. A micellar electrokinetic chromatography method was developed for the simultaneous determination of eight lignans – schizandrin, schisandrol B, schisantherin A, schisanhenol, anwulignan, deoxyschizandrin, schizandrin B and schizandrin C – in different parts of S. sphenanthera. The key factors for separation and determination were studied and the best analysis conditions were obtained using a background electrolyte of 10 mM phosphate-37.5 mM SDS-35% v/v acetonitrile (pH 8.0) at the separation voltage of 28 kV and detection at 214 nm, whereby the plant samples could be analyzed within 9.0 min. Analysis yielded good reproducibility (RSD between 1.19-2.28%) and good recovery (between 92.2-103.8%). The detection limits (LOD) and limit of quantification (LOQ) were within 0.4-1.2 mg/L and 1.5-4.0 mg/L. This method is promising to improve the quality control of different parts of S. sphenanthera. Full article
Open AccessArticle Acylation of Heteroaromatic Amines: Facile and Efficient Synthesis of a New Class of 1,2,3-Triazolo[4,5-b]pyridine and Pyrazolo[4,3-b]pyridine Derivatives
Molecules 2011, 16(5), 3723-3739; doi:10.3390/molecules16053723
Received: 14 March 2011 / Revised: 21 April 2011 / Accepted: 26 April 2011 / Published: 4 May 2011
Cited by 6 | PDF Full-text (674 KB)
Abstract
1,2,3-Triazolo[4,5-b]pyridines and pyrazolo[4,3-b]pyridines can be readily prepared via cyanoacetylation reactions of 5-amino-1,2,3-triazoles 1a,b and 4-amino- pyrazole 2 followed by subsequent cyclization of the formed cyanoacetamides. Reactions of amines 1a,b with a mixture of p-nitrophenylacetic acid and
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1,2,3-Triazolo[4,5-b]pyridines and pyrazolo[4,3-b]pyridines can be readily prepared via cyanoacetylation reactions of 5-amino-1,2,3-triazoles 1a,b and 4-amino- pyrazole 2 followed by subsequent cyclization of the formed cyanoacetamides. Reactions of amines 1a,b with a mixture of p-nitrophenylacetic acid and acetic anhydride under microwave irradiation conditions afforded the corresponding amides 15a,b that underwent cyclization to form 1,2,3-triazolo[4,5-b]pyridines 16a,b upon heating in DMF solutions containing sodium acetate. Reactions of 1a,b with active methylene compounds, including 17a-c, in the presence of zeolites as catalyst also afforded 1,2,3-triazolo[4,5-b]pyridine derivatives 20a-f via the intermediacy of triazole derivatives 19 and not 18. Full article
(This article belongs to the Section Organic Synthesis)
Figures

Open AccessArticle Crystallization Products of Risedronate with Carbohydrates and Their Substituted Derivatives
Molecules 2011, 16(5), 3740-3760; doi:10.3390/molecules16053740
Received: 7 February 2011 / Revised: 11 April 2011 / Accepted: 3 May 2011 / Published: 4 May 2011
Cited by 4 | PDF Full-text (978 KB)
Abstract
The gastrointestinal absorption of bisphosphonates is in general only about 1%. To address this problem mixtures of risedronate monosodium salt with twelve varied sugar alcohols, furanoses, pyranoses and eight gluco-, manno- and galactopyranoside derivatives as counterions were designed in an effort to prepare
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The gastrointestinal absorption of bisphosphonates is in general only about 1%. To address this problem mixtures of risedronate monosodium salt with twelve varied sugar alcohols, furanoses, pyranoses and eight gluco-, manno- and galactopyranoside derivatives as counterions were designed in an effort to prepare co-crystals/new entities with improved intestinal absorption. Crystalline forms were generated by means of kinetically and/or thermodynamically controlled crystallization processes. One hundred and fifty-two prepared samples were screened by means of FT-NIR and FT-Raman spectroscopy. No co-crystal was prepared, but noteworthy results were obtained. A new solid phase of risedronate monosodium salt generated in the presence of phenyl-β-d-galactopyranoside under thermodynamically controlled crystallization conditions was found and also characterized using solid state NMR spectroscopy, X-ray powder diffraction and differential scanning calorimetry. This new polymorph was named as form P. Interactions between risedronate monosodium salt and both carbohydrates were confirmed by means of molecular dynamics simulation. In the present study the relationships between the chemical structures of the studied compounds required for crystalline form change are discussed. Full article
(This article belongs to the Special Issue ECSOC-14)
Open AccessArticle Enhancement of Leaf Gas Exchange and Primary Metabolites under Carbon Dioxide Enrichment Up-Regulates the Production of Secondary Metabolites in Labisia pumila Seedlings
Molecules 2011, 16(5), 3761-3777; doi:10.3390/molecules16053761
Received: 14 February 2011 / Revised: 11 April 2011 / Accepted: 12 April 2011 / Published: 4 May 2011
Cited by 21 | PDF Full-text (214 KB)
Abstract
A split plot 3 by 3 experiment was designed to investigate and distinguish the relationships among production of primary metabolites (soluble sugar and starch), secondary metabolites (total phenolics, TP; total flavonoids, TF) and leaf gas exchange of three varieties of the Malaysian medicinal
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A split plot 3 by 3 experiment was designed to investigate and distinguish the relationships among production of primary metabolites (soluble sugar and starch), secondary metabolites (total phenolics, TP; total flavonoids, TF) and leaf gas exchange of three varieties of the Malaysian medicinal herb Labisia pumila Blume, namely the varieties alata, pumila and lanceolata, under three levels of CO2 enrichment (400, 800 and 1,200 µmol mol−1) for 15 weeks. The treatment effects were solely contributed by CO2 enrichment levels; no varietal differences were observed. As CO2 levels increased from 400 to 1,200 µmol mol−1, the production of carbohydrates also increased steadily, especially for starch more than soluble sugar (sucrose). TF and TP content, simultaneously, reached their peaks under 1,200 µmol exposure, followed by 800 and 400 µmol mol−1. Net photosynthesis (A) and quantum efficiency of photosystem II (fv/fm) were also enhanced as CO2 increased from 400 to 1,200 µmol mol−1. Leaf gas exchange characteristics displayed a significant positive relationship with the production of secondary metabolites and carbohydrate contents. The increase in production of TP and TFs were manifested by high C/N ratio and low protein content in L. pumila seedlings, and accompanied by reduction in cholorophyll content that exhibited very significant negative relationships with total soluble sugar, starch and total non structural carbohydrate. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Asymmetric Aldol Reactions of α,β-Unsaturated Ketoester Substrates Catalyzed by Chiral Diamines
Molecules 2011, 16(5), 3778-3786; doi:10.3390/molecules16053778
Received: 14 March 2011 / Revised: 16 April 2011 / Accepted: 20 April 2011 / Published: 4 May 2011
Cited by 11 | PDF Full-text (221 KB)
Abstract
Highly efficient asymmetric aldol reactions between α,β-unsaturated keto esters and acyclic ketones catalyzed by chiral diamines are reported. The corresponding products were obtained in excellent yields with excellent enantioselectivities. The absolute configuration for the product was determined by X-ray analysis. A variety of
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Highly efficient asymmetric aldol reactions between α,β-unsaturated keto esters and acyclic ketones catalyzed by chiral diamines are reported. The corresponding products were obtained in excellent yields with excellent enantioselectivities. The absolute configuration for the product was determined by X-ray analysis. A variety of substrates were tolerable in the present catalytic system. Full article
Open AccessArticle Antihyperglycemic Effect of Orthosiphon Stamineus Benth Leaves Extract and Its Bioassay-Guided Fractions
Molecules 2011, 16(5), 3787-3801; doi:10.3390/molecules16053787
Received: 5 February 2011 / Revised: 30 March 2011 / Accepted: 15 April 2011 / Published: 4 May 2011
Cited by 14 | PDF Full-text (197 KB)
Abstract
Preliminary investigations were carried out to evaluate the antidiabetic effects of the leaves of O. stamineus extracted serially with solvents of increasing polarity (petroleum ether, chloroform, methanol and water); bioassay-guided purification of plant extracts using the subcutaneous glucose tolerance test (SbGTT) was also
[...] Read more.
Preliminary investigations were carried out to evaluate the antidiabetic effects of the leaves of O. stamineus extracted serially with solvents of increasing polarity (petroleum ether, chloroform, methanol and water); bioassay-guided purification of plant extracts using the subcutaneous glucose tolerance test (SbGTT) was also carried out. Only the chloroform extract, given at 1 g/kg body weight (b.w.), significantly reduced (P < 0.05) the blood glucose level of rats loaded subcutaneously with 150 mg/kg (b.w.) glucose. The active chloroform extract of O. stamineus was separated into five fractions using a dry flash column chromatography method. Out of the five fractions tested, only chloroform fraction 2 (Cƒ2), at the dose of 1 g/kg (b.w.) significantly inhibited (P < 0.05) blood glucose levels in SbGTT. Active Cƒ2 was split into two sub-fractions Cƒ2-A and Cƒ2-B, using a dry flash column chromatography method. The activities Cƒ2-A and Cƒ2-B were investigated using SbGTT, and the active sub-fraction was then further studied for anti-diabetic effects in a streptozotocin-induced diabetic rat model. The results clearly indicate that Cƒ2-B fraction exhibited a blood glucose lowering effect in fasted treated normal rats after glucose-loading of 150 mg/kg (b.w.). In the acute streptozotocin-induced diabetic rat model, Cƒ2-B did not exhibit a hypoglycemic effect on blood glucose levels up to 7 hours after treatment. Thus, it appears that Cƒ2-B functions similarly to metformin, which has no hypoglycemic effect but demonstrates an antihyperglycemic effect only in normogycemic models. The effect of Cƒ2-B may have no direct stimulatory effects on insulin secretion or on blood glucose levels in diabetic animal models. Verification of the active compound(s) within the active fraction (Cƒ2-B) indicated the presence of terpenoids and, flavonoids, including sinensitin. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Diversity-Oriented Synthesis Based on the DPPP-Catalyzed Mixed Double-Michael Reactions of Electron-Deficient Acetylenes and β-Amino Alcohols
Molecules 2011, 16(5), 3802-3825; doi:10.3390/molecules16053802
Received: 6 April 2011 / Revised: 29 April 2011 / Accepted: 5 May 2011 / Published: 5 May 2011
Cited by 11 | PDF Full-text (311 KB)
Abstract
In this study, we prepared oxizolidines through 1,3-bis(diphenylphosphino)-propane (DPPP)–catalyzed mixed double-Michael reactions of b-amino alcohols with electron-deficient acetylenes. These reactions are very suitable for the diversity-oriented parallel syntheses of oxizolidines because: (i) they are performed under mild metal-free conditions and (ii) the products
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In this study, we prepared oxizolidines through 1,3-bis(diphenylphosphino)-propane (DPPP)–catalyzed mixed double-Michael reactions of b-amino alcohols with electron-deficient acetylenes. These reactions are very suitable for the diversity-oriented parallel syntheses of oxizolidines because: (i) they are performed under mild metal-free conditions and (ii) the products are isolated without complicated work-up. To demonstrate the applicability of mixed double-Michael reactions for the preparation of five-membered-ring heterocycles, we prepared 60 distinct oxazolidines from five β-amino alcohols and 12 electron-deficient acetylenes. We synthesized 36 of these 60 oxazolidines in enantiomerically pure form from proteinogenic amino acid–derived β-amino alcohols. Full article
(This article belongs to the Special Issue Diversity Oriented Synthesis)
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Open AccessArticle Synthesis of Homoveratric Acid-Imprinted Polymers and Their Evaluation as Selective Separation Materials
Molecules 2011, 16(5), 3826-3844; doi:10.3390/molecules16053826
Received: 13 January 2011 / Revised: 16 March 2011 / Accepted: 28 April 2011 / Published: 5 May 2011
Cited by 5 | PDF Full-text (1192 KB)
Abstract
A bulk polymerization method was used to easily and efficiently prepare homo-veratric acid (3,4-dimethoxyphenylacetic acid)-imprinted polymers from eight basic monomers: 2-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, N-allylaniline, N-allylpiperazine, allylurea, allylthiourea, and allylamine, in the presence of homoveratric acid as a template in N,
[...] Read more.
A bulk polymerization method was used to easily and efficiently prepare homo-veratric acid (3,4-dimethoxyphenylacetic acid)-imprinted polymers from eight basic monomers: 2-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, N-allylaniline, N-allylpiperazine, allylurea, allylthiourea, and allylamine, in the presence of homoveratric acid as a template in N,N-dimethylformamide as a porogen. The imprinted polymer prepared from allylamine had the highest affinity to the template, showing an imprinting factor of 3.43, and allylamine polymers MIP8/NIP8 were selected for further studies. Their binding properties were analyzed using the Scatchard method. The results showed that the imprinted polymers have two classes of heterogeneous binding sites characterized by two pairs of Kd, Bmax values: Kd(1) = 0.060 μmol/mL, Bmax(1) = 0.093 μmol/mg for the higher affinity binding sites, and Kd(2) = 0.455 μmol/mL, Bmax(2) = 0.248 μmol/mg for the lower affinity binding sites. Non-imprinted polymer has only one class of binding site, with Kd = 0.417 μmol/mL and Bmax = 0.184 μmol/mg. A computational analysis of the energies of the prepolymerization complexes was in agreement with the experimental results. It showed that the selective binding interactions arose from cooperative three point interactions between the carboxylic acid and the two methoxy groups in the template and amino groups in the polymer cavities. Those results were confirmed by the recognition studies performed with the set of structurally related compounds. Allylamine polymer MIP8 had no affinity towards biogenic amines. The obtained imprinted polymer could be used for selective separation of homoveratric acid. Full article
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Open AccessArticle Optimization of the Selective Monohydrolysis of Diethyl 4-Aryl-4H-pyran-3,5-dicarboxylates
Molecules 2011, 16(5), 3845-3854; doi:10.3390/molecules16053845
Received: 5 April 2011 / Revised: 15 April 2011 / Accepted: 18 April 2011 / Published: 6 May 2011
PDF Full-text (158 KB)
Abstract
A simple, efficient and eco-friendly procedure for the selective monohydrolysis of diethyl 2,6-dimethyl-4-aryl-4H-pyran-3,5-dicarboxylates under quaternary ammonium salt catalysis conditions is presented. The catalytic activities of various quaternary ammonium salts were investigated using different molar ratios of NaOH and water-organic solvent mixtures.
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A simple, efficient and eco-friendly procedure for the selective monohydrolysis of diethyl 2,6-dimethyl-4-aryl-4H-pyran-3,5-dicarboxylates under quaternary ammonium salt catalysis conditions is presented. The catalytic activities of various quaternary ammonium salts were investigated using different molar ratios of NaOH and water-organic solvent mixtures. The results indicate that the combination of 1.0 equivalent of tetraethyl-ammonium bromide (TEAB) with 1.2 equivalents of NaOH in a 10% water-ethanol media at 40 °C displays remarkable selectivity for the monohydrolysis of diethyl 2,6-dimethyl-4-aryl-4H-pyran-3,5-dicarboxylates. The utility of this process is demonstrated by the monohydrolysis of a series of 4-aryl-4H-pyran-3,5-dicarboxylate esters to afford the corresponding monoesters in 20–80% yields under the optimized conditions. Full article
Open AccessArticle RuCl3·3H2O Catalyzed Reactions: Facile Synthesis of Bis(indolyl)methanes under Mild Conditions
Molecules 2011, 16(5), 3855-3868; doi:10.3390/molecules16053855
Received: 23 March 2011 / Revised: 20 April 2011 / Accepted: 25 April 2011 / Published: 9 May 2011
Cited by 24 | PDF Full-text (225 KB)
Abstract
RuCl3·3H2O was found to be an effective catalyst for reactions of indoles, 2-methylthiophene, and 2-methylfuran with aldehydes to afford the corresponding bis(indolyl)methanes, bis(thienyl)methanes, and bis(fur-2-yl)methanes in moderate to excellent yields. Experimental results indicated that mono(indolyl)methanol is not the reaction
[...] Read more.
RuCl3·3H2O was found to be an effective catalyst for reactions of indoles, 2-methylthiophene, and 2-methylfuran with aldehydes to afford the corresponding bis(indolyl)methanes, bis(thienyl)methanes, and bis(fur-2-yl)methanes in moderate to excellent yields. Experimental results indicated that mono(indolyl)methanol is not the reaction intermediate under these reaction conditions. Full article
(This article belongs to the Special Issue Organometallic Chemistry)
Open AccessArticle Two New Iridoid Glycosides from the Root Barks of Sambucus williamsii Hance
Molecules 2011, 16(5), 3869-3874; doi:10.3390/molecules16053869
Received: 15 April 2011 / Revised: 28 April 2011 / Accepted: 29 April 2011 / Published: 9 May 2011
Cited by 7 | PDF Full-text (191 KB)
Abstract
Chemical investigation of the ethanol extract of the root barks of Sambucus williamsii Hance collected in the Heilongjiang province of China resulted in the isolation of two new iridoid glycosides, williamsoside A (1) and williamsoside B (2). Their structures
[...] Read more.
Chemical investigation of the ethanol extract of the root barks of Sambucus williamsii Hance collected in the Heilongjiang province of China resulted in the isolation of two new iridoid glycosides, williamsoside A (1) and williamsoside B (2). Their structures were elucidated on the basis of extensive spectroscopic analysis (1D, 2D-NMR and HRESIMS) and chemical studies. Iridoid glycosides have for a long time been considered as characteristic ingredients of S. williamsii. However, the presence of iridoid glycosides with apiofuranosyl moieties in S. williamsii is reported for the first time in this study. Full article
Open AccessArticle Anti-Inflammatory Activity of Methyl Salicylate Glycosides Isolated from Gaultheria yunnanensis (Franch.) Rehder
Molecules 2011, 16(5), 3875-3884; doi:10.3390/molecules16053875
Received: 12 February 2010 / Revised: 28 April 2011 / Accepted: 6 May 2011 / Published: 9 May 2011
Cited by 33 | PDF Full-text (379 KB)
Abstract
Gaultheria yunnanensis (Franch.) Rehder is a kind of traditional Chinese herbal medicine used for the treatments of rheumatoid arthritis, swelling and pain. Two methyl salicylate glycosides, namely methyl benzoate-2-O-b-D-xylopyranosyl(1-6)-O-b-D-gluco-pyranoside (J12122) and methyl benzoate-2-O-
[...] Read more.
Gaultheria yunnanensis (Franch.) Rehder is a kind of traditional Chinese herbal medicine used for the treatments of rheumatoid arthritis, swelling and pain. Two methyl salicylate glycosides, namely methyl benzoate-2-O-b-D-xylopyranosyl(1-6)-O-b-D-gluco-pyranoside (J12122) and methyl benzoate-2-O-β-D-xylopyranosyl(1-2)[O-β-D-xylopyranosyl(1-6)]-O-β-D-glucopyranoside (J12123), are natural salicylic derivatives isolated from Gaultheria yunnanensis. In this study, we investigated the anti-inflammatory activity of J12122 and J12123 on LPS-induced RAW264.7 macrophage cells by measuring the production of pro-inflammatory cytokines, accumulation of nitric oxide (NO), and level of reactive oxygen species (ROS). The results showed that both methyl salicylate glycosides dose-dependently inhibited the production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6, respectively. Consistent with these observations, J12122 and J12123 significantly suppressed the accumulation of NO, with an inhibitory rate of 56.20% and 51.72% at 3.0 μg/mL concentration, respectively. Furthermore, the two methyl salicylate glycosides reduced the level of ROS induced by LPS. These results showed that the isolated compounds possess anti-inflammatory properties through inhibition the production pro-inflammatory cytokines, NO, and ROS. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Fungitoxicity against Botrytis cinerea of a Flavonoid Isolated from Pseudognaphalium robustum
Molecules 2011, 16(5), 3885-3895; doi:10.3390/molecules16053885
Received: 8 March 2011 / Revised: 30 April 2011 / Accepted: 5 May 2011 / Published: 9 May 2011
Cited by 7 | PDF Full-text (273 KB)
Abstract
The fungotoxicity against Botrytis cinerea of a flavonoid isolated from Pseudognaphalium robustum was analyzed. Two absorption column chromatographies and one semipreparative thin layer chromatography were used to purify the active flavonoid. It was determined, by 1H-NMR spectroscopy and co-elution with standards in
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The fungotoxicity against Botrytis cinerea of a flavonoid isolated from Pseudognaphalium robustum was analyzed. Two absorption column chromatographies and one semipreparative thin layer chromatography were used to purify the active flavonoid. It was determined, by 1H-NMR spectroscopy and co-elution with standards in HPLC, that this compound was 5,7-dihydroxy-3,8-dimethoxyflavone (gnaphaliin A). To determine the fungitoxicity of the purified compound, the effect on in vitro mycelial growth and conidial germination was studied. The compound concentration that reduced mycelial growth by 50% was 45.5 mg/mL. This compound also partially affected conidial germination of B. cinerea, reduced oxygen consumption by germinating conidia and affected the integrity of plasma membrane. Finally, using cyclic voltammetry, it was shown that the purified flavone had a pro-oxidant effect. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Astragaloside IV Improves Metabolic Syndrome and Endothelium Dysfunction in Fructose-Fed Rats
Molecules 2011, 16(5), 3896-3907; doi:10.3390/molecules16053896
Received: 12 January 2011 / Revised: 28 April 2011 / Accepted: 4 May 2011 / Published: 10 May 2011
Cited by 21 | PDF Full-text (330 KB)
Abstract
The prevalence of metabolic syndrome has increased in modern society and the condition is proving to be a common precursor of cardiovascular disease. The aim of the present study was to investigate whether astragaloside IV, a major active constituent of Astragalus membranaceus (Fisch)
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The prevalence of metabolic syndrome has increased in modern society and the condition is proving to be a common precursor of cardiovascular disease. The aim of the present study was to investigate whether astragaloside IV, a major active constituent of Astragalus membranaceus (Fisch) Bge., is able to prevent the development of hypertension and endothelial dysfunction in fructose-fed rats. Rats were fed with 10% fructose in their drinking water for 8 weeks. From the beginning of week 5, two groups of fructose-fed rats were treated with 0.5 or 2 mg/kg, i.p., astragaloside IV. Another group of fructose-fed rats, injected with the same volume of vehicle (dimethylsulfoxide, DMSO) from week 5, served as the control group. At the end of the treatment period, blood pressure, blood glucose, glucose tolerance, blood insulin and lipids were determined. In addition, in vitro experiments were conducted at the end of the eight week treatment period to evaluate endothelium-dependent aortic vasorelaxation, as well as myocardial and aortic tissue levels of nitrate and nitrite (NOx) and cGMP. Fructose-fed rats developed clustering signs of metabolic syndrome, such as increased bodyweight, mild hypertension, hyperinsulinaemia, hypertriglyceridaemia, impaired glucose tolerance and impaired endothelium-dependent vasorelaxation. Administration of astragaloside IV reduced blood pressure and triglyceride levels in fructose-fed rats and high dose of astragaloside IV also improved glucose tolerance and endothelium-dependent vasorelaxation. The astragaloside IV-induced improvement in vasorelaxation was associated with increased levels of aortic NOx and cGMP and was abrogated by blockade of nitric oxide synthase with NG-nitro-l-arginine methyl ester (l-NAME). On the basis of its favourable effects on lipid metabolism, endothelium-dependent vasorelaxation and the nitric oxide–cGMP-related pathway, astragaloside IV may be useful in ameliorating food-induced metabolic syndrome. Full article
Open AccessArticle Effects of Thai Medicinal Herb Extracts with Anti-Psoriatic Activity on the Expression on NF-κB Signaling Biomarkers in HaCaT Keratinocytes
Molecules 2011, 16(5), 3908-3932; doi:10.3390/molecules16053908
Received: 25 March 2011 / Revised: 25 April 2011 / Accepted: 4 May 2011 / Published: 10 May 2011
Cited by 22 | PDF Full-text (967 KB)
Abstract
Psoriasis is a chronic inflammatory skin disorder characterized by rapid proliferation of keratinocytes and incomplete keratinization. Discovery of safer and more effective anti-psoriatic drugs remains an area of active research at the present time. Using a HaCaT keratinocyte cell line as an in
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Psoriasis is a chronic inflammatory skin disorder characterized by rapid proliferation of keratinocytes and incomplete keratinization. Discovery of safer and more effective anti-psoriatic drugs remains an area of active research at the present time. Using a HaCaT keratinocyte cell line as an in vitro model, we had previously found that ethanolic extracts from three Thai medicinal herbs, namely Alpinia galanga, Curcuma longa and Annona squamosa, possessed anti-psoriatic activity. In the current study, we aimed at investigating if these Thai medicinal herb extracts played a molecular role in suppressing psoriasis via regulation of NF-κB signaling biomarkers. Using semi-quantitative RT-PCR and report gene assays, we analyzed the effects of these potential herbal extracts on 10 different genes of the NF-κB signaling network in HaCaT cells. In accordance with our hypothesis, we found that the extract derived from Alpinia galanga significantly increased the expression of TNFAIP3 and significantly reduced the expression of CSF-1 and NF-kB2. Curcuma longa extract significantly decreased the expression of CSF-1, IL-8, NF-kB2, NF-kB1 and RelA, while Annona squamosa extract significantly lowered the expression of CD40 and NF-kB1. Therefore, this in vitro study suggested that these herbal extracts capable of functioning against psoriasis, might exert their activity by controlling the expression of NF-κB signaling biomarkers. Full article
Open AccessArticle Consecutive Low Doses of Cyclosporine A Induce Pro-Inflammatory Cytokines and Accelerate Allograft Skin Rejection
Molecules 2011, 16(5), 3969-3984; doi:10.3390/molecules16053969
Received: 24 February 2011 / Revised: 29 April 2011 / Accepted: 6 May 2011 / Published: 11 May 2011
Cited by 3 | PDF Full-text (887 KB)
Abstract
Cyclosporine A (CsA) is a fungus-derived molecule with potent immunosuppressive activity that has been largely used to downregulate cell-mediated immune responses during transplantation. However, previous data have indicated that CsA shows immunomodulatory activity that relays on the antigen concentration and the dose of
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Cyclosporine A (CsA) is a fungus-derived molecule with potent immunosuppressive activity that has been largely used to downregulate cell-mediated immune responses during transplantation. However, previous data have indicated that CsA shows immunomodulatory activity that relays on the antigen concentration and the dose of CsA used. To test the hypothesis that minimal doses of CsA may show different outcomes on grafts, we used an experimental model for skin transplants in mice. ICR outbred mice received skin allografts and were either treated daily with different doses of CsA or left untreated. Untreated mice showed allograft rejection within 14 days, with graft necrosis, infiltration of neutrophils and macrophages and displayed high percentages of CD8+ T cells in the spleens, which were associated with high serum levels of IL-12, IFN-g and TNF-α. As expected, mice treated with therapeutic doses of CsA (15 mg/kg) did not show allograft rejection within the follow-up period of 30 days and displayed the lowest levels of IL-12, IFN-g and TNF-α as well as a reduction in CD8+ lymphocytes. In contrast, mice treated with consecutive minimal doses of CsA (5 × 10−55 mg/kg) displayed an acute graft rejection as early as one to five days after skin allograft; they also displayed necrosis and strong inflammatory infiltration that was associated with high levels of IL-12, IFN-g and TNF-α. Moreover, the CD4+ CD25hiFoxP3+ subpopulation of cells in the spleens of these mice was significantly inhibited compared with animals that received the therapeutic treatment of CsA and those treated with placebo. Our data suggest that consecutive, minimal doses of CsA may affect Treg cells and may stimulate innate immunity. Full article
(This article belongs to the collection Bioactive Compounds)
Open AccessArticle Synthesis of a Novel Benzoyl Adenosine Analog Containing a 1, 4-Dioxane Sugar Analog and the Synthesis of a Corresponding Uracil Adenine Dinucleotide
Molecules 2011, 16(5), 3985-3998; doi:10.3390/molecules16053985
Received: 3 March 2011 / Revised: 28 April 2011 / Accepted: 6 May 2011 / Published: 12 May 2011
PDF Full-text (259 KB)
Abstract
Adenosine analogs in which the sugar unit was replaced by a 1,4-dioxane sugar equivalent, were prepared by coupling the 1,4-dioxane sugar analog as its anomeric acetates, with N6-benzoyl protected adenine. The 1,4-dioxane system was obtained in an enantioselective synthesis from (R,R
[...] Read more.
Adenosine analogs in which the sugar unit was replaced by a 1,4-dioxane sugar equivalent, were prepared by coupling the 1,4-dioxane sugar analog as its anomeric acetates, with N6-benzoyl protected adenine. The 1,4-dioxane system was obtained in an enantioselective synthesis from (R,R)-dimethyl tartrate. Using standard phosphorimidite methodology, the adenine analog was further reacted with a 1,4-dioxane uridine analog to give the corresponding, protected dinucleotide, set-up for further condensation into larger oligonucleotides. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle A New Pyranoxanthone from Calophyllum soulattri
Molecules 2011, 16(5), 3999-4004; doi:10.3390/molecules16053999
Received: 21 March 2011 / Revised: 8 April 2011 / Accepted: 19 April 2011 / Published: 12 May 2011
PDF Full-text (186 KB)
Abstract
Our interest on xanthones from the Calophyllum genus has led us to a detailed study on the chemistry of the stem bark of Calophyllum soulattri. This gave one new pyranoxanthone, soulattrin (1), together with three other xanthones, caloxanthone B (2
[...] Read more.
Our interest on xanthones from the Calophyllum genus has led us to a detailed study on the chemistry of the stem bark of Calophyllum soulattri. This gave one new pyranoxanthone, soulattrin (1), together with three other xanthones, caloxanthone B (2), caloxanthone C (3), macluraxanthone (4), the triterpene friedelin (5) and the steroid stigmasterol (6). The identities of these compounds were established using analyses of 1D and 2D NMR data. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Apigenin Isolated from the Medicinal Plant Elsholtzia rugulosa Prevents β-Amyloid 25–35-Induces Toxicity in Rat Cerebral Microvascular Endothelial Cells
Molecules 2011, 16(5), 4005-4019; doi:10.3390/molecules16054005
Received: 28 March 2011 / Revised: 28 April 2011 / Accepted: 5 May 2011 / Published: 13 May 2011
Cited by 10 | PDF Full-text (329 KB)
Abstract
Endothelial cells of cerebral capillaries forming the blood-brain barrier play an important role in the pathogenesis and therapy of Alzheimer’s disease. Amyloid-β peptides are key pathological elements in the development of this disease. Apigenin (4’,5,7-tetrahydroxyflavone) is a plant flavonoid and pharmacologically active agent
[...] Read more.
Endothelial cells of cerebral capillaries forming the blood-brain barrier play an important role in the pathogenesis and therapy of Alzheimer’s disease. Amyloid-β peptides are key pathological elements in the development of this disease. Apigenin (4’,5,7-tetrahydroxyflavone) is a plant flavonoid and pharmacologically active agent that can be isolated from several plant species. In the present study, effects of apigenin obtained from the medicinal plant Elsholtzia rugulosa (Labiatae) on primary cultured rat cerebral microvascular endothelial cells (CMECs) mediated by amyloid-β peptide 25–35 (Aβ25–35) were examined. Aβ25–35 showed toxic effects on CMECs, involving reduction of cell viability, release of lactate dehydrogenase (LDH), increase of nuclear condensation, over-production of intracellular reactive oxygen species (ROS), decrease of superoxide dismutase (SOD) activity, and breakage of the barrier integrity and function. Based on this model, we demonstrated that apigenin from the medicinal plant Elsholtzia rugulosa protected cultured rat CMECs by increasing cell viability, reducing LDH release, relieving nuclear condensation, alleviating intracellular ROS generation, increasing SOD activity, and strengthening the barrier integrity through the preservation of transendothelial electrical resistance, permeability property and characteristic enzymatic activity after being exposed to Aβ25–35. In conclusion, apigenin isolated from Elsholtzia rugulosa has the ability to protect rat CMECs against Aβ25–35-induced toxicity. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Antioxidant and Cytotoxic Constituents from Wisteria sinensis
Molecules 2011, 16(5), 4020-4030; doi:10.3390/molecules16054020
Received: 5 February 2011 / Revised: 13 May 2011 / Accepted: 16 May 2011 / Published: 17 May 2011
PDF Full-text (1103 KB)
Abstract
Chromatographic separation of an aqueous MeOH extract of Wisteria sinensis leaves has yielded six known flavonoids, two triterpene aglycones and the new acylated flavone glycoside chrysoeriol-7-O-[2''-O-(5'''-O-caffeoyl)-β-D-apiofuranosyl]-β-D-glucopyranoside (1). All metabolites were isolated
[...] Read more.
Chromatographic separation of an aqueous MeOH extract of Wisteria sinensis leaves has yielded six known flavonoids, two triterpene aglycones and the new acylated flavone glycoside chrysoeriol-7-O-[2''-O-(5'''-O-caffeoyl)-β-D-apiofuranosyl]-β-D-glucopyranoside (1). All metabolites were isolated for the first time from the genus Wisteria. Their structures were established on the basis of their chromatographic properties, chemical and physicochemical methods including acid hydrolysis analysis, spectroscopic (UV, 1H- and 13C-NMR) data and confirmed by ESI-MS analysis, as well as two-dimensional NMR (1H-1HCOSY, HMQC and HMBC). Biological studies of the defatted aqueous 80% methanol leaf extract and the major isolates 1, 6 and 7 were undertaken and they are reported herein for the first time to have significant cytotoxic activity against the Hep-G2 tumor cell line in addition to antioxidant activity. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle Dehydration of (Perfluoroalkyl)tetramethylcyclopentenols
Molecules 2011, 16(5), 4031-4044; doi:10.3390/molecules16054031
Received: 23 March 2011 / Revised: 4 May 2011 / Accepted: 11 May 2011 / Published: 17 May 2011
PDF Full-text (258 KB)
Abstract
(Perfluoroalkyl) tetramethylcyclopentenols (alkyl = n-butyl, n-hexyl, n-octyl) were dehydrated to a complex mixture of endo, endo-(perfluoroalkyl) tetramethyl-cyclopentadienes and their endo-, exo-isomers. It was found in preliminary screening experiments that the best reagent for this transformation, giving an 89%
[...] Read more.
(Perfluoroalkyl) tetramethylcyclopentenols (alkyl = n-butyl, n-hexyl, n-octyl) were dehydrated to a complex mixture of endo, endo-(perfluoroalkyl) tetramethyl-cyclopentadienes and their endo-, exo-isomers. It was found in preliminary screening experiments that the best reagent for this transformation, giving an 89% yield of isomeric product mixture, was P2O5 in benzene at 80-90 °C. Products were characterized on the basis of their mass spectra and retention time information, and some peaks in the mass spectra were identified from their molecular fragments. Structures were assigned to the three most abundant products of (perfluorohexyl)tetramethylcyclopentenol dehydration. Formal dehydration kinetics showed a second order reaction in benzene but zeroth order with induction period in chlorobenzene, suggesting mass transfer limitations in the more polar chlorobenzene. Some of the products were formed by consecutive isomerization of the others, as shown by the kinetic analysis. Full article
(This article belongs to the Special Issue Fluorine Chemistry 2016)
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Open AccessArticle The Effects of Co-Treatment of 9-cis-Retinoic Acid and 15-Deoxy-Δ (12,14)-prostaglandin J2 on Microglial Activation
Molecules 2011, 16(5), 4045-4058; doi:10.3390/molecules16054045
Received: 28 February 2011 / Revised: 26 April 2011 / Accepted: 16 May 2011 / Published: 17 May 2011
PDF Full-text (539 KB)
Abstract
Microglial activation plays an important role in the regulation of neuronal function and contributes to the development of neurodegeneration in Alzheimer’s disease (AD). Activation of nuclear peroxisome proliferator-activated receptor gamma (PPARγ) by an endogenous agonist, 15-deoxy-Δ(12,14)-prostaglandin J2 (15d-PGJ2), has been shown to be
[...] Read more.
Microglial activation plays an important role in the regulation of neuronal function and contributes to the development of neurodegeneration in Alzheimer’s disease (AD). Activation of nuclear peroxisome proliferator-activated receptor gamma (PPARγ) by an endogenous agonist, 15-deoxy-Δ(12,14)-prostaglandin J2 (15d-PGJ2), has been shown to be beneficial in many diseases with aberrant immune responses. Here, we report that co-treatment with 15d-PGJ2 and its synergistic partner, 9-cis-retinoic acid (RA), may modulate, but not abolish, microglial immune response activated by β-amyloid (Aβ) and interferon gamma (IFNγ). The co-treatment of RA and 15d-PGJ2 inhibited Aβ/IFNγ-activated immune response in primary microglia, as evidenced by suppressed expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2); and the effect was not affected by treatment with a PPARγ antagonist, GW9662. Data suggest that PPARγ activation may not contribute to the anti-inflammatory properties of the co-treatment. The co-treatment promoted microglial Aβ clearance in cultures; and the effect can be prevented by blocking PPARγ activation using GW9662. The effects of the co-treatment on Aβ clearance may be PPARγ-dependent. Intriguingly, secretion of microglial pro-nerve growth factor (pro-NGF) was inhibited by Aβ/IFNg treatment in a dose-dependent manner, suggesting that secretion of microglial pro-NGF may not contribute to the Ab/IFNg-activated microglial immune response. Taken together, the co-treatment may be beneficial for AD therapy; however, our data suggest that multiple mechanisms may underlie the beneficial effects of the co-treatment and are not limited to PPARγ activation only. Full article
(This article belongs to the Special Issue Neuroactive Compounds)
Open AccessArticle Synthesis of Ginkgolic Acid Analogues and Evaluation of Their Molluscicidal Activity
Molecules 2011, 16(5), 4059-4069; doi:10.3390/molecules16054059
Received: 16 March 2011 / Revised: 23 April 2011 / Accepted: 9 May 2011 / Published: 17 May 2011
Cited by 2 | PDF Full-text (196 KB)
Abstract
Based on the molluscicidal activity of ginkgolic acids (GAs) isolated from Ginkgo biloba L, a series of Z/E isomers of GA analogues were prepared and evaluated for their molluscicidal activities against the host snail Oncomelania hupensis. The results and analysis
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Based on the molluscicidal activity of ginkgolic acids (GAs) isolated from Ginkgo biloba L, a series of Z/E isomers of GA analogues were prepared and evaluated for their molluscicidal activities against the host snail Oncomelania hupensis. The results and analysis of the structure-activity relationship revealed that the E-isomers showed better molluscicidal activities than their Z-isomers. Molluscicidal activities decreased with the shortening of the alkenyl chain lengths. Full article
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Open AccessArticle Copper(I)-Catalyzed [ 3+ 2] Cycloaddition of 3-Azidoquinoline-2,4(1H,3H)-diones with Terminal Alkynes
Molecules 2011, 16(5), 4070-4081; doi:10.3390/molecules16054070
Received: 18 April 2011 / Revised: 11 May 2011 / Accepted: 13 May 2011 / Published: 18 May 2011
Cited by 2 | PDF Full-text (182 KB)
Abstract
3-Azidoquinoline-2,4(1H,3H)-diones 1, which are readily available from 4-hydroxyquinolin-2(1H)-ones 4 via 3-chloroquinoline-2,4(1H,3H)-diones 5, afford, in copper(I)-catalyzed [3 + 2] cycloaddition reaction with terminal acetylenes, 1,4-disubstituted 1,2,3-triazoles 3 in moderate to excellent yields.
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3-Azidoquinoline-2,4(1H,3H)-diones 1, which are readily available from 4-hydroxyquinolin-2(1H)-ones 4 via 3-chloroquinoline-2,4(1H,3H)-diones 5, afford, in copper(I)-catalyzed [3 + 2] cycloaddition reaction with terminal acetylenes, 1,4-disubstituted 1,2,3-triazoles 3 in moderate to excellent yields. The structures of compounds 3 were confirmed by 1H and 13C-NMR spectroscopy, combustion analyses and mass spectrometry. Full article
(This article belongs to the Section Organic Synthesis)
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Open AccessArticle Chemical Composition, Antioxidant and Antimicrobial Activity of Pericarpium Citri Reticulatae Essential Oil
Molecules 2011, 16(5), 4082-4096; doi:10.3390/molecules16054082
Received: 21 February 2011 / Revised: 29 April 2011 / Accepted: 3 May 2011 / Published: 18 May 2011
Cited by 9 | PDF Full-text (221 KB)
Abstract
The chemical composition, antioxidant and antimicrobial activity of Pericarpium Citri Reticulatae (PCR) essential oil obtained using an improved Clevenger type apparatus were studied. Among the five different PCRs examined the highest yield of essential oil was found in Chachi 2004 (harvested and stored
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The chemical composition, antioxidant and antimicrobial activity of Pericarpium Citri Reticulatae (PCR) essential oil obtained using an improved Clevenger type apparatus were studied. Among the five different PCRs examined the highest yield of essential oil was found in Chachi 2004 (harvested and stored in 2004) and the lowest in Chachi 2008 (harvested and stored in 2008). Fifty three different volatile compounds were determined, including terpenic hydrocarbons, alcohols, aldehydes, ketones and esters. D-limonene, one of terpenes, was the major constituent in PCR. The antioxidant capacity of PCR essential oil varied considerably with the duration of storage time, and the oil from Chachi 1994 has the strongest ferric-reducing antioxidant power. In addition, the essential oil possessed varying degrees of antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus), except Streptococcus faecalis, while had no effect on Gram-negative bacteria (Escherichia coli, Enterobacter cloacae). Full article
Open AccessArticle Synthesis of the Key Intermediate of Coenzyme Q10
Molecules 2011, 16(5), 4097-4103; doi:10.3390/molecules16054097
Received: 24 March 2011 / Revised: 9 May 2011 / Accepted: 9 May 2011 / Published: 18 May 2011
Cited by 4 | PDF Full-text (149 KB)
Abstract
(2’E)-1-(3-methyl-4-p-toluenesulfonyl-2-butene)-6-methyl-2,3,4,5-tetramethoxybenzene (4) is the key intermediate in the synthesis of coenzyme Q10via a coupling reaction with solanesyl bromide. In this paper, we report a simple and effective synthesis of compound 4, starting with the
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(2’E)-1-(3-methyl-4-p-toluenesulfonyl-2-butene)-6-methyl-2,3,4,5-tetramethoxybenzene (4) is the key intermediate in the synthesis of coenzyme Q10 via a coupling reaction with solanesyl bromide. In this paper, we report a simple and effective synthesis of compound 4, starting with the readily available and inexpensive precursors p-toluenesulfonyl chloride (TsCl) and isoprene to obtain (2E)-1-p-toluenesulfonyl-2-methyl-4-hydroxy-2-butene (3) by addition, esterification and hydrolysis. Application of the Friedel-Crafts alkylation to compound 3, followed by the addition of 2,3,4,5-tetramethoxytoluene (TeMT), assembled the two parts into compound 4. The key parameters of each reaction were optimized at the same time, and the four total operations needed to produced compound 4 had a 27.9% overall yield under the optimized conditions. The structures of the compounds were characterized by 1H-NMR, IR and MS. This alternative process has the potential to be used for large-scale process. Full article
(This article belongs to the Section Organic Synthesis)
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Open AccessArticle Solid-Phase Synthesis of Arylpiperazine Derivatives and Implementation of the Distributed Drug Discovery (D3) Project in the Search for CNS Agents
Molecules 2011, 16(5), 4104-4121; doi:10.3390/molecules16054104
Received: 13 April 2011 / Revised: 14 May 2011 / Accepted: 16 May 2011 / Published: 19 May 2011
Cited by 2 | PDF Full-text (318 KB)
Abstract
We have successfully implemented the concept of Distributed Drug Discovery (D3) in the search for CNS agents. Herein, we demonstrate, for the first time, student engagement from different sites around the globe in the development of new biologically active compounds. As an outcome
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We have successfully implemented the concept of Distributed Drug Discovery (D3) in the search for CNS agents. Herein, we demonstrate, for the first time, student engagement from different sites around the globe in the development of new biologically active compounds. As an outcome we have synthesized a 24-membered library of arylpiperazine derivatives targeted to 5-HT1A and 5-HT2A receptors. The synthesis was simultaneously performed on BAL-MBHA-PS resin in Poland and the United States, and on BAL-PS-SynPhase Lanterns in France. The D3 project strategy opens the possibility of obtaining potent 5-HT1A/5-HT2A agents in a distributed fashion. While the biological testing is still centralized, this combination of distributed synthesis with screening will enable a D3 network of students world-wide to participate, as part of their education, in the synthesis and testing of this class of biologically active compounds. Full article
(This article belongs to the Section Medicinal Chemistry)
Open AccessArticle The Influence of t-Butyl and Cyclododecyl Substitution on Ethylene/1-Hexene Copolymerization Using Ansa-Fluorenylamidodimethyltitanium Derivatives
Molecules 2011, 16(5), 4122-4130; doi:10.3390/molecules16054122
Received: 9 March 2011 / Revised: 9 May 2011 / Accepted: 12 May 2011 / Published: 19 May 2011
Cited by 1 | PDF Full-text (399 KB)
Abstract
In the present study, copolymerization of ethylene and 1-hexene was conducted with a series of ansa-fluorenylamidodimethyltitanium complexes, including [t-BuNSiMe2Flu]TiMe2 (complex 1), [cyclododecylNSiMe2Flu]TiMe2 (complex 2) and [t-BuNSiMe2(2,7-t-Bu2Flu)]TiMe2
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In the present study, copolymerization of ethylene and 1-hexene was conducted with a series of ansa-fluorenylamidodimethyltitanium complexes, including [t-BuNSiMe2Flu]TiMe2 (complex 1), [cyclododecylNSiMe2Flu]TiMe2 (complex 2) and [t-BuNSiMe2(2,7-t-Bu2Flu)]TiMe2 (complex 3), activated by MMAO. The effect of these catalysts on catalytic behavior, namely activity, molecular weight and monomer reactivity ratios, has been investigated. The results showed that all of them acted by a single site polymerization mechanism and the molecular weight distribution is independent of catalyst structure. Based on the study, it revealed that the introduction of a t-butyl at the 2,7 position on the fluorenyl ligand is able to enhance both catalytic activity and copolymer molecular weight more than introducing a cyclododecyl on the amine, which is probably associated with the electronic effect exerted by the t-butyl substituent. The comonomer incorporation content was controllable over a wide range by adjusting the comonomer feed ratio. Moreover, referring to monomer reactivity ratio exploration, it seems that the substitution on the ansa-fluorenylamidodimethyltitanium complex tends to hinder the insertion of 1-hexene into the polymer chain, leading to the highest 1-hexene content for traditional complex 1. Full article
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Open AccessArticle Effects of Agronomic Practices on Volatile Composition of Hyssopus officinalis L. Essential Oils
Molecules 2011, 16(5), 4131-4139; doi:10.3390/molecules16054131
Received: 24 March 2011 / Revised: 6 May 2011 / Accepted: 12 May 2011 / Published: 19 May 2011
Cited by 8 | PDF Full-text (257 KB)
Abstract
The chemical composition of Hyssopus officinalis (Lamiaceae) essential oil grown in southeastern Spain was analyzed by GC-MS. Due to the high relevance of this species in the world market, the study is focused on chemical heterogeneity of different oil batches and their extraction
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The chemical composition of Hyssopus officinalis (Lamiaceae) essential oil grown in southeastern Spain was analyzed by GC-MS. Due to the high relevance of this species in the world market, the study is focused on chemical heterogeneity of different oil batches and their extraction yield, cultivated under irrigation and non-irrigation conditions and with different harvesting dates. All essential oil samples have two main terpene compounds which are pinocamphone and iso-pinocamphone, accounting for approximately 35–40% of the total oil content. Other relevant compounds were identified, with β-pinene, which accounted for 10–17% contribution to the total composition, standing out. Significant differences between their volatile composition have been observed between treatments, being limonene, (E)-β-ocimene, pinocarveol, α-pinene and β-phellandrene the compounds that contributed most to the discrimination. It was also observed that the irrigation period is the most favourable for the cultivation of hyssop in this region, specially for batch 7 which gives the highest extraction yield and the best EO quality. Full article
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Open AccessCommunication A Regioselective Synthesis of E-Guggulsterone
Molecules 2011, 16(5), 4165-4171; doi:10.3390/molecules16054165
Received: 18 April 2011 / Revised: 17 May 2011 / Accepted: 18 May 2011 / Published: 20 May 2011
Cited by 3 | PDF Full-text (158 KB)
Abstract We have successfully prepared E-guggulsterone from 16,17-epoxy-pregnenolone in 84% yield over two steps via a hydrazine reduction and Oppenhauer oxidation. Additionally, isomerization was induced by heat, light (hn) and acid catalysis to convert E- guggulsterone into the corresponding Z isomer. Full article
Open AccessArticle Involvement of Carbohydrate, Protein and Phenylanine Ammonia Lyase in Up-Regulation of Secondary Metabolites in Labisia pumila under Various CO2 and N2 Level
Molecules 2011, 16(5), 4172-4190; doi:10.3390/molecules16054172
Received: 8 March 2011 / Revised: 25 April 2011 / Accepted: 26 April 2011 / Published: 20 May 2011
Cited by 20 | PDF Full-text (210 KB)
Abstract
A split plot factorial 2 × 3 experiment was designed to examine and characterize the relationships among secondary metabolites (total phenolics, TP; total flavonoids, TF), carbohydrate content, C/N ratio, protein synthesis and L–phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity in the Malaysian medicinal
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A split plot factorial 2 × 3 experiment was designed to examine and characterize the relationships among secondary metabolites (total phenolics, TP; total flavonoids, TF), carbohydrate content, C/N ratio, protein synthesis and L–phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity in the Malaysian medicinal herb Labisia pumila (Blume) Fern-Vill. under different CO2 concentrations (400 = ambient and 1,200 µmol mol−1 CO2) and three levels of nitrogen fertilization (0, 90 and 270 kg N ha−1) for 15 weeks. The interaction between CO2 and nitrogen levels imposed a significant impact on plant secondary metabolite production, protein, PAL activity and fructose levels. Highest TP and TF were recorded under 1,200 µmol mol−1 CO2 when N fertilizer was not applied; lowest values were obtained at 400 µmol mol−1 CO2 fertilized with the highest N level. Concurrently, fructose contents increased tremendously. Increase in fructose content might also enhance erythose-4-phosphate production (substrate for lignin and phenolic compounds), which shares a common precursor transdalolase in the pentose phosphate pathway. PAL activity was noted to be highest under 1,200 µmol mol−1 CO2 + 0 kg N ha−1 coinciding with subsequent recording of the lowest protein content. The results implied that the increase in plant secondary metabolites production under the tested conditions might be due to diversion of phenylalanine for protein synthesis to production of secondary metabolites. It was also found that the sucrose to starch ratio was also high under high levels of nitrogen fertilization, indicating an enhanced sucrose phosphate synthase activity (SPS; EC 2.4.1.14) under such condition. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle The Effect of Ultrasound on the Functional Properties of Wheat Gluten
Molecules 2011, 16(5), 4231-4240; doi:10.3390/molecules16054231
Received: 21 March 2011 / Revised: 13 May 2011 / Accepted: 18 May 2011 / Published: 23 May 2011
Cited by 10 | PDF Full-text (702 KB)
Abstract
In this study, the effect of ultrasound on the foaming and emulsifying properties of wheat gluten as well as its electrophoretic and rheology properties were investigated. The foam capacity and foam stability of ultrasound treated wheat gluten proteins gradually increased as the treatment
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In this study, the effect of ultrasound on the foaming and emulsifying properties of wheat gluten as well as its electrophoretic and rheology properties were investigated. The foam capacity and foam stability of ultrasound treated wheat gluten proteins gradually increased as the treatment power increased, and were more pronounced at 100% power level. Excluding those of the raw wheat gluten, the lowest emulsifying capacity values and emulsifying stability were obtained with the samples ultrasound treated at 60% power level. In general, ultrasound treatment did not cause major changes on the protein electrophoretic patterns of gluten samples at the power levels used. Ultrasound affected the storage and the loss moduli with typical U-shape alteration. Full article
Open AccessArticle In Vitro Antibacterial and Antifungal Activity of Lavandula x intermedia Emeric ex Loisel. ‘Budrovka’
Molecules 2011, 16(5), 4241-4253; doi:10.3390/molecules16054241
Received: 13 April 2011 / Revised: 18 May 2011 / Accepted: 18 May 2011 / Published: 23 May 2011
Cited by 4 | PDF Full-text (111 KB)
Abstract
This study aimed to evaluate the in vitro antibacterial and antifungal activities of Lavandula x intermedia Emeric ex Loisel. ‘Budrovka’, an indigenous Croatian cultivar of lavandin. For that purpose the activity of ethanolic extracts of flowers, inflorescence stalks and leaves against thirty one
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This study aimed to evaluate the in vitro antibacterial and antifungal activities of Lavandula x intermedia Emeric ex Loisel. ‘Budrovka’, an indigenous Croatian cultivar of lavandin. For that purpose the activity of ethanolic extracts of flowers, inflorescence stalks and leaves against thirty one strains of bacteria, yeasts, dermatophytes and moulds were studied using both the agar well diffusion and broth dilution assays. Among the investigated extracts found to be effective against a broad spectrum of microorganisms, the flower extract was considered to be the most potent one. Linalool and rosmarinic acid, as the most abundant constituents found, are very likely major contributors to the observed antimicrobial effects. The results suggest that flowers of lavandin ‘Budrovka’ could serve as a rich source of natural terpene and polyphenol antimicrobial agents. Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Cytotoxicity and Pro-Apoptotic Activity of 2,2´-Bis[4,5-bis(4-hydroxybenzyl)-2-(4-hydroxyphenyl)cyclopent-4-en-1,3-dione], a Phenolic Cyclopentenedione Isolated from the Cyanobacterium Strain Nostoc sp. str. Lukešová 27/97
Molecules 2011, 16(5), 4254-4263; doi:10.3390/molecules16054254
Received: 14 March 2011 / Revised: 13 May 2011 / Accepted: 18 May 2011 / Published: 23 May 2011
Cited by 7 | PDF Full-text (399 KB)
Abstract
The cytotoxicity of the polyphenol 2,2´-bis[4,5-bis(4-hydroxybenzyl)-2-(4-hydroxyphenyl)cyclopent-4-en-1,3-dione], nostotrebin 6 (NOS-6), was tested under in vitro conditions using mouse fibroblasts (BALB/c cells). Identification of NOS-6 and its uptake into fibroblasts was examined by multi-stage mass spectrometry analysis with the following fragmentation pattern: MS (m/z
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The cytotoxicity of the polyphenol 2,2´-bis[4,5-bis(4-hydroxybenzyl)-2-(4-hydroxyphenyl)cyclopent-4-en-1,3-dione], nostotrebin 6 (NOS-6), was tested under in vitro conditions using mouse fibroblasts (BALB/c cells). Identification of NOS-6 and its uptake into fibroblasts was examined by multi-stage mass spectrometry analysis with the following fragmentation pattern: MS (m/z) [M+H]+ 799.1 → MS2 399.1 → MS3 305.1 → MS4 277.1. Using several cell viability assays, the IC50 of NOS-6 after 24 h incubation was found to be 8.48 ± 0.16/12.15 ± 1.96 µM (neutral red/MTT assay) which was higher than that of doxorubicin. It was found that NOS-6 is capable of inducing both types of cell death, apoptosis and necrosis in a dose-dependent manner. The biological activities of the cyclopentenediones and preliminary data on NOS-6 cytotoxicity are discussed. Full article
(This article belongs to the collection Bioactive Compounds)
Open AccessArticle Mangiferin, an Anti-HIV-1 Agent Targeting Protease and Effective against Resistant Strains
Molecules 2011, 16(5), 4264-4277; doi:10.3390/molecules16054264
Received: 25 February 2011 / Revised: 6 May 2011 / Accepted: 13 May 2011 / Published: 24 May 2011
Cited by 24 | PDF Full-text (468 KB)
Abstract
The anti-HIV-1 activity of mangiferin was evaluated. Mangiferin can inhibit HIV-1B induced syncytium formation at non-cytotoxic concentrations, with a 50% effective concentration (EC50) at 16.90 μM and a therapeutic index (TI) above 140. Mangiferin also showed good activities in
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The anti-HIV-1 activity of mangiferin was evaluated. Mangiferin can inhibit HIV-1B induced syncytium formation at non-cytotoxic concentrations, with a 50% effective concentration (EC50) at 16.90 μM and a therapeutic index (TI) above 140. Mangiferin also showed good activities in other laboratory-derived strains, clinically isolated strains and resistant HIV-1 strains. Mechanism studies revealed that mangiferin might inhibit the HIV-1 protease, but is still effective against HIV peptidic protease inhibitor resistant strains. A combination of docking and pharmacophore methods clarified possible binding modes of mangiferin in the HIV-1 protease. The pharmacophore model of mangiferin consists of two hydrogen bond donors and two hydrogen bond acceptors. Compared to pharmacophore features found in commercially available drugs, three pharmacophoric elements matched well and one novel pharmacophore element was observed. Moreover, molecular docking analysis demonstrated that the pharmacophoric elements play important roles in binding HIV-1 protease. Mangiferin is a novel nonpeptidic protease inhibitor with an original structure that represents an effective drug development strategy for combating drug resistance. Full article
(This article belongs to the Special Issue Antivirals)
Open AccessArticle A Screening of a Library of T7 Phage-Displayed Peptide Identifies E2F-4 as an Etoposide-Binding Protein
Molecules 2011, 16(5), 4278-4294; doi:10.3390/molecules16054278
Received: 1 March 2011 / Revised: 22 April 2011 / Accepted: 16 May 2011 / Published: 24 May 2011
Cited by 5 | PDF Full-text (506 KB)
Abstract
Etoposide (VP-16) is an anti-tumor compound that targets topoisomerase II (top II). In this study, we have identified an alternative binding protein of etoposide by screening a library of T7 phage-displayed peptides. After four rounds of selection using a biotinylated etoposide derivative immobilized
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Etoposide (VP-16) is an anti-tumor compound that targets topoisomerase II (top II). In this study, we have identified an alternative binding protein of etoposide by screening a library of T7 phage-displayed peptides. After four rounds of selection using a biotinylated etoposide derivative immobilized on a streptavidin-coated plate, T7 phage particles that display a 16-mer peptide NSSASSRGNSSSNSVY (ETBP16) or a 10-mer NSLRKYSKLK (ETBP10) were enriched with the ratio of 40 or 11 out of the 69 clones, respectively. Binding of etoposide to these peptides was confirmed by surface plasmon resonance (SPR) analysis, which showed ETBP16 and ETBP10 to have a kinetic constant of 4.85 × 10−5 M or 6.45 × 10−5 M, respectively. ETBP16 displays similarity with the ser-rich domain in E2F-4, a transcription factor in cell cycle-regulated genes, suggesting that etoposide might interact with E2F-4 via this domain. SPR analysis confirmed the specific binding of etoposide to recombinant E2F-4 is in the order of 10−5 M. Furthermore, etoposide was shown to inhibit luciferase reporter gene expression mediated by the heterodimeric E2F-4/DP complex. Taken together, our results suggest that etoposide directly binds to E2F-4 and inhibits subsequent gene transcription mediated by heterodimeric E2F-4/DP complexes in the nucleus. Full article
(This article belongs to the collection Bioactive Compounds)
Open AccessArticle Transformation of Geniposide into Genipin by Immobilized β-Glucosidase in a Two-Phase Aqueous-Organic System
Molecules 2011, 16(5), 4295-4304; doi:10.3390/molecules16054295
Received: 15 February 2011 / Revised: 3 May 2011 / Accepted: 13 May 2011 / Published: 24 May 2011
Cited by 16 | PDF Full-text (278 KB)
Abstract
Genipin is the bioactive compound of geniposide and a natural cross-linking agent. In order to improve the preparation process of genipin, the hydrolysis of geniposide to genipin by immobilized β-glucosidase in an aqueous-organic two-phase system was studied. β-Glucosidase was immobilized by the crosslinking-embedding
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Genipin is the bioactive compound of geniposide and a natural cross-linking agent. In order to improve the preparation process of genipin, the hydrolysis of geniposide to genipin by immobilized β-glucosidase in an aqueous-organic two-phase system was studied. β-Glucosidase was immobilized by the crosslinking-embedding method using sodium alginate as the carrier. The optimum reaction temperature, pH value and time were 55 °C, 4.5 and 2.5 h, respectively. To reduce genipin hydrolysis and byproduct production the reaction was carried out in an aqueous-organic two-phase system comprising ethyl acetate and sodium acetate buffer. The product was analyzed by HPLC, UV, IR, and NMR. The yield of genipin was 47.81% and its purity was over 98% (HPLC). Full article
(This article belongs to the Section Natural Products)
Open AccessArticle Synthesis, and Antitumor Activity of Some N1-(Coumarin-7-yl) Amidrazones and Related Congeners
Molecules 2011, 16(5), 4305-4317; doi:10.3390/molecules16054305
Received: 8 April 2011 / Revised: 9 May 2011 / Accepted: 11 May 2011 / Published: 24 May 2011
Cited by 16 | PDF Full-text (191 KB)
Abstract
A series of new N1-(coumarin-7-yl)amidrazones incorporating N-piperazines and related congeners were synthesized by reacting the hydrazonoyl chloride derived from 7-amino-4-methylcoumarin with the appropriate piperazines. The chemical structures of the newly prepared compounds were supported by elemental analyses, 1H-NMR, 13C-NMR,
[...] Read more.
A series of new N1-(coumarin-7-yl)amidrazones incorporating N-piperazines and related congeners were synthesized by reacting the hydrazonoyl chloride derived from 7-amino-4-methylcoumarin with the appropriate piperazines. The chemical structures of the newly prepared compounds were supported by elemental analyses, 1H-NMR, 13C-NMR, and ESI-HRMS spectral data. The antitumor activity of the newly synthesized compounds was evaluated. Among all the compounds tested, 7-{2-[1-(4-(1-benzyl-2-ethyl-4-nitro-1H-imidazol-5-yl)piperazin-1-yl)-2-oxopropylidene]hydrazinyl}-4-methyl-2H-chromen-2-one (3n) was the most potent against MCF-7 and K562 cells, with IC50 values of 20.2 and 9.3 μM, respectively. Full article
Open AccessArticle Chemical Composition, and Antioxidant and Antimicrobial Activities of Essential Oil of Phyllostachys heterocycla cv. Pubescens Varieties from China
Molecules 2011, 16(5), 4318-4327; doi:10.3390/molecules16054318
Received: 11 April 2011 / Revised: 14 May 2011 / Accepted: 17 May 2011 / Published: 24 May 2011
Cited by 3 | PDF Full-text (181 KB)
Abstract
The essential oils of Phyllostachys heterocycla cv. Pubescens, Phyllostachys heterocycla cv. Gracilis, Phyllostachys heterocycla cv. Heterocycla and Phyllostachys kwangsiensis leaves were obtained by steam distillation. Their chemical components were separated and identified by gas chromatography/mass spectrometry (GC/MS). Meanwhile, the effect of
[...] Read more.
The essential oils of Phyllostachys heterocycla cv. Pubescens, Phyllostachys heterocycla cv. Gracilis, Phyllostachys heterocycla cv. Heterocycla and Phyllostachys kwangsiensis leaves were obtained by steam distillation. Their chemical components were separated and identified by gas chromatography/mass spectrometry (GC/MS). Meanwhile, the effect of scavenging free radicals of essential oil was assayed by using the DPPH·method with Trolox® as control to evaluate their antioxidant capacities. Gram-positive (Staphyloccocus aureus) and Gram-negative (Escherichia coli) were selected as the indicator microorganisms to evaluate the antimicrobial activity. Antimicrobial properties were estimated by the agar diffusion method. The results show that 63 components were separated and identified by GC/MS from these varieties of bamboo leaves. cis-3-Hexenol, whose content in cv. Pubescens, Gracilis, Heterocycla and Ph. kwangsiensis was 27.11%, 24.62%, 30.51% and 34.65%, respectively, was the main constituent. The relative content of alcohol compounds in these varieties of essential oils ranged from 39.8% to 46.64%. All of the bamboo leaf essential oils possessed certain antioxidant capacity; the corresponding IC50 values were 3.1622, 4.9353, 4.2473, and 5.4746 μL/mL, respectively. Essential oils of all tested bamboo spp. were active against Staphylococcus epidermidis and E. coli, showing a positive correlation with the essential oil concentration of 50.42-300 μL/mL. The results indicated there were no significant differences among three varieties and the related species with respect to their antioxidant and antimicrobial activities. This paper provides evidence for studying the essential composition from different varieties of bamboo leaves. Full article
(This article belongs to the collection Bioactive Compounds)

Review

Jump to: Research

Open AccessReview Phage Display of Combinatorial Peptide Libraries: Application to Antiviral Research
Molecules 2011, 16(5), 3499-3518; doi:10.3390/molecules16053499
Received: 12 March 2011 / Revised: 21 April 2011 / Accepted: 22 April 2011 / Published: 26 April 2011
Cited by 32 | PDF Full-text (292 KB)
Abstract
Given the growing number of diseases caused by emerging or endemic viruses, original strategies are urgently required: (1) for the identification of new drugs active against new viruses and (2) to deal with viral mutants in which resistance to existing antiviral molecules has
[...] Read more.
Given the growing number of diseases caused by emerging or endemic viruses, original strategies are urgently required: (1) for the identification of new drugs active against new viruses and (2) to deal with viral mutants in which resistance to existing antiviral molecules has been selected. In this context, antiviral peptides constitute a promising area for disease prevention and treatment. The identification and development of these inhibitory peptides require the high-throughput screening of combinatorial libraries. Phage-display is a powerful technique for selecting unique molecules with selective affinity for a specific target from highly diverse combinatorial libraries. In the last 15 years, the use of this technique for antiviral purposes and for the isolation of candidate inhibitory peptides in drug discovery has been explored. We present here a review of the use of phage display in antiviral research and drug discovery, with a discussion of optimized strategies combining the strong screening potential of this technique with complementary rational approaches for identification of the best target. By combining such approaches, it should be possible to maximize the selection of molecules with strong antiviral potential. Full article
(This article belongs to the Special Issue Phage Display of Combinatorial Libraries)
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Open AccessReview Molecular Morphology of Pituitary Cells, from Conventional Immunohistochemistry to Fluorescein Imaging
Molecules 2011, 16(5), 3618-3635; doi:10.3390/molecules16053618
Received: 9 March 2011 / Revised: 25 April 2011 / Accepted: 26 April 2011 / Published: 29 April 2011
Cited by 3 | PDF Full-text (1988 KB) | Correction | Supplementary Files
Abstract
In situ hybridization (ISH) at the electron microscopic (EM) level is essential for elucidating the intracellular distribution and role of mRNA in protein synthesis. EM-ISH is considered to be an important tool for clarifying the intracellular localization of mRNA and the exact site
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In situ hybridization (ISH) at the electron microscopic (EM) level is essential for elucidating the intracellular distribution and role of mRNA in protein synthesis. EM-ISH is considered to be an important tool for clarifying the intracellular localization of mRNA and the exact site of pituitary hormone synthesis on the rough endoplasmic reticulum. A combined ISH and immunohistochemistry (IHC) under EM (EM-ISH&IHC) approach has sufficient ultrastructural resolution, and provides two-dimensional images of the subcellular localization of pituitary hormone and its mRNA in a pituitary cell. The advantages of semiconductor nanocrystals (quantum dots, Qdots) and confocal laser scanning microscopy (CLSM) enable us to obtain three-dimensional images of the subcellular localization of pituitary hormone and its mRNA. Both EM-ISH&IHC and ISH & IHC using Qdots and CLSM are useful for understanding the relationships between protein and mRNA simultaneously in two or three dimensions. CLSM observation of rab3B and SNARE proteins such as SNAP-25 and syntaxin has revealed that both rab3B and SNARE system proteins play important roles and work together as the exocytotic machinery in anterior pituitary cells. Another important issue is the intracellular transport and secretion of pituitary hormone. We have developed an experimental pituitary cell line, GH3 cell, which has growth hormone (GH) linked to enhanced yellow fluorescein protein (EYFP). This stable GH3 cell secretes GH linked to EYFP upon stimulation by Ca2+ influx or Ca2+ release from storage. This GH3 cell line is useful for the real-time visualization of the intracellular transport and secretion of GH. These three methods from conventional immunohistochemistry and fluorescein imaging allow us to consecutively visualize the process of transcription, translation, transport and secretion of anterior pituitary hormone. Full article
Open AccessReview High Affinity, Developability and Functional Size: The Holy Grail of Combinatorial Antibody Library Generation
Molecules 2011, 16(5), 3675-3700; doi:10.3390/molecules16053675
Received: 23 March 2011 / Revised: 20 April 2011 / Accepted: 22 April 2011 / Published: 3 May 2011
Cited by 48 | PDF Full-text (723 KB)
Abstract
Since the initial description of phage display technology for the generation of human antibodies, a variety of selection methods has been developed. The most critical parameter for all in vitro-based approaches is the quality of the antibody library. Concurrent evolution of the
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Since the initial description of phage display technology for the generation of human antibodies, a variety of selection methods has been developed. The most critical parameter for all in vitro-based approaches is the quality of the antibody library. Concurrent evolution of the libraries has allowed display and selection technologies to reveal their full potential. They come in different flavors, from naïve to fully synthetic and differ in terms of size, quality, method of preparation, framework and CDR composition. Early on, the focus has mainly been on affinities and thus on library size and diversity. Subsequently, the increased awareness of developability and cost of goods as important success factors has spurred efforts to generate libraries with improved biophysical properties and favorable production characteristics. More recently a major focus on reduction of unwanted side effects through reduced immunogenicity and improved overall biophysical behavior has led to a re-evaluation of library design. Full article
(This article belongs to the Special Issue Phage Display of Combinatorial Libraries)
Open AccessReview Synthesis of Glycosides of Glucuronic, Galacturonic and Mannuronic Acids: An Overview
Molecules 2011, 16(5), 3933-3968; doi:10.3390/molecules16053933
Received: 24 March 2011 / Revised: 18 April 2011 / Accepted: 20 April 2011 / Published: 10 May 2011
Cited by 21 | PDF Full-text (472 KB)
Abstract
Uronic acids are carbohydrates present in relevant biologically active compounds. Most of the latter are glycosides or oligosaccharides linked by their anomeric carbon, so their synthesis requires glycoside-bond formation. The activation of this anomeric center remains difficult due to the presence of the
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Uronic acids are carbohydrates present in relevant biologically active compounds. Most of the latter are glycosides or oligosaccharides linked by their anomeric carbon, so their synthesis requires glycoside-bond formation. The activation of this anomeric center remains difficult due to the presence of the electron-withdrawing C-5 carboxylic group. Herein we present an overview of glucuronidation, mannuronidation and galacturonidation reactions, including syntheses of prodrugs, oligosaccharides and stereochemical aspects. Full article
(This article belongs to the Special Issue Glycosides)
Open AccessReview Aminolevulinic Acid (ALA) as a Prodrug in Photodynamic Therapy of Cancer
Molecules 2011, 16(5), 4140-4164; doi:10.3390/molecules16054140
Received: 3 February 2011 / Accepted: 3 May 2011 / Published: 19 May 2011
Cited by 48 | PDF Full-text (456 KB)
Abstract
Aminolevulinic acid (ALA) is an endogenous metabolite normally formed in the mitochondria from succinyl-CoA and glycine. Conjugation of eight ALA molecules yields protoporphyrin IX (PpIX) and finally leads to formation of heme. Conversion of PpIX to its downstream substrates requires the activity of
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Aminolevulinic acid (ALA) is an endogenous metabolite normally formed in the mitochondria from succinyl-CoA and glycine. Conjugation of eight ALA molecules yields protoporphyrin IX (PpIX) and finally leads to formation of heme. Conversion of PpIX to its downstream substrates requires the activity of a rate-limiting enzyme ferrochelatase. When ALA is administered externally the abundantly produced PpIX cannot be quickly converted to its final product - heme by ferrochelatase and therefore accumulates within cells. Since PpIX is a potent photosensitizer this metabolic pathway can be exploited in photodynamic therapy (PDT). This is an already approved therapeutic strategy making ALA one of the most successful prodrugs used in cancer treatment. Full article
(This article belongs to the Special Issue Prodrugs)
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Open AccessReview Synthesis, Properties Characterization and Applications of Various Organobismuth Compounds
Molecules 2011, 16(5), 4191-4230; doi:10.3390/molecules16054191
Received: 15 April 2011 / Revised: 9 May 2011 / Accepted: 12 May 2011 / Published: 20 May 2011
Cited by 14 | PDF Full-text (418 KB)
Abstract
Organobismuth chemistry was emphasized in this review article due to the low price, low toxicity and low radioactivity characteristics of bismuth. As an environmentally-friendly class of organometallic compounds, different types of organobismuth compounds have been used in organic synthesis, catalysis, materials, etc. The
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Organobismuth chemistry was emphasized in this review article due to the low price, low toxicity and low radioactivity characteristics of bismuth. As an environmentally-friendly class of organometallic compounds, different types of organobismuth compounds have been used in organic synthesis, catalysis, materials, etc. The synthesis and property characterization of many organobismuth compounds had been summarized. This review article also presented a survey of various applications of organobismuth compounds in organic transformations, as reagents or catalysts. The reactivity, reaction pathways and mechanisms of reactions with organobismuths were discussed. Less common and limiting aspects of organobismuth compounds were also briefly mentioned. Full article
(This article belongs to the Special Issue Organometallic Chemistry)

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