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Molecules, Volume 16, Issue 10 (October 2011), Pages 8143-8929

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Open AccessArticle Determination of Capsaicin and Dihydrocapsaicin in Capsicum Fruit Samples using High Performance Liquid Chromatography
Molecules 2011, 16(10), 8919-8929; https://doi.org/10.3390/molecules16108919
Received: 22 August 2011 / Revised: 14 October 2011 / Accepted: 15 October 2011 / Published: 24 October 2011
Cited by 74 | PDF Full-text (329 KB)
Abstract
The aim of the present study was to determine the content of capsaicin and dihydrocapsaicin in Capsicum samples collected from city markets in Riyadh (Saudi Arabia), calculate their pungency in Scoville heat units (SHU) and evaluate the average daily intake of capsaicin for
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The aim of the present study was to determine the content of capsaicin and dihydrocapsaicin in Capsicum samples collected from city markets in Riyadh (Saudi Arabia), calculate their pungency in Scoville heat units (SHU) and evaluate the average daily intake of capsaicin for the population of Riyadh. The investigated samples consisted of hot chillies, red chillies, green chillies, green peppers, red peppers and yellow peppers. Extraction of capsaicinoids was done using ethanol as solvent, while high performance liquid chromatography (HPLC) was used for separation, identification and quantitation of the components. The limit of detection (LOD) of the method was 0.09 and 0.10 µg/g for capsaicin and dihydrocapsaicin, respectively, while the limit of quantification (LOQ) was 0.30 and 0.36 µg/g for capsaicin and dihydrocapsaicin, respectively. Hot chillies showed the highest concentration of capsaicin (4249.0 ± 190.3 µg/g) and the highest pungency level (67984.60 SHU), whereas green peppers had the lowest detected concentration (1.0 ± 0.9 µg/g); green peppers, red peppers and yellow peppers were non pungent. The mean consumption of peppers for Riyadh city population was determined to be 15.5 g/person/day while the daily capsaicin intake was 7.584 mg/person/day. Full article
(This article belongs to the Section Natural Products Chemistry)
Open AccessReview Silver Nanoparticles as Potential Antiviral Agents
Molecules 2011, 16(10), 8894-8918; https://doi.org/10.3390/molecules16108894
Received: 1 September 2011 / Revised: 30 September 2011 / Accepted: 19 October 2011 / Published: 24 October 2011
Cited by 173 | PDF Full-text (380 KB)
Abstract
Virus infections pose significant global health challenges, especially in view of the fact that the emergence of resistant viral strains and the adverse side effects associated with prolonged use continue to slow down the application of effective antiviral therapies. This makes imperative the
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Virus infections pose significant global health challenges, especially in view of the fact that the emergence of resistant viral strains and the adverse side effects associated with prolonged use continue to slow down the application of effective antiviral therapies. This makes imperative the need for the development of safe and potent alternatives to conventional antiviral drugs. In the present scenario, nanoscale materials have emerged as novel antiviral agents for the possibilities offered by their unique chemical and physical properties. Silver nanoparticles have mainly been studied for their antimicrobial potential against bacteria, but have also proven to be active against several types of viruses including human imunodeficiency virus, hepatitis B virus, herpes simplex virus, respiratory syncytial virus, and monkey pox virus. The use of metal nanoparticles provides an interesting opportunity for novel antiviral therapies. Since metals may attack a broad range of targets in the virus there is a lower possibility to develop resistance as compared to conventional antivirals. The present review focuses on the development of methods for the production of silver nanoparticles and on their use as antiviral therapeutics against pathogenic viruses. Full article
(This article belongs to the Special Issue Antivirals)
Open AccessArticle Autotoxicity and Allelopathy of 3,4-Dihydroxyacetophenone Isolated from Picea schrenkiana Needles
Molecules 2011, 16(10), 8874-8893; https://doi.org/10.3390/molecules16108874
Received: 19 September 2011 / Revised: 9 October 2011 / Accepted: 17 October 2011 / Published: 24 October 2011
Cited by 22 | PDF Full-text (2401 KB)
Abstract
Bioassay-guided fractionation of the diethyl ether fraction of a water extract of Picea schrenkiana needles led to the isolation of the phenolic compound 3,4-dihydroxy- acetophenone (DHAP). The allelopathic effects of DHAP were evaluated under laboratory conditions on P. schrenkiana, rice (Oryza
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Bioassay-guided fractionation of the diethyl ether fraction of a water extract of Picea schrenkiana needles led to the isolation of the phenolic compound 3,4-dihydroxy- acetophenone (DHAP). The allelopathic effects of DHAP were evaluated under laboratory conditions on P. schrenkiana, rice (Oryza sativa L.), wheat (Triticum aestivum L.), radish (Raphanus sativus L.), lettuce (Latuca sativa L.), cucumber (Cucumis sativus L.) and mung bean (Phaseolus radiatus L.). DHAP significantly inhibited seed germination and seedling growth of P. schrenkiana at concentrations of 2.5 mM and 0.5 mM (p < 0.05). Soil analysis revealed that P. schrenkiana forest soils contained exceptionally high DHAP concentrations (mean = 0.51 ± 0.03 mg/g dry soil), sufficient to inhibit natural P. schrenkiana recruitment. DHAP also exhibited strong allelopathic potential. It significantly inhibited wheat and lettuce seed germination at concentrations of 1 mM and 0.5 mM (p < 0.05). The active compound also completely inhibited root growth of the six test species at high concentrations. Our results suggest a dual role of DHAP, both as an allelochemical and as an autotoxicant. The potential for a single plant needle-leached compound to influence both inter- and intra-specific interactions emphasized the complex effects that plant secondary metabolites might have on plant population and community structure. Full article
(This article belongs to the Section Natural Products Chemistry)
Open AccessCommunication A New Languidulane Diterpenoid from Salvia mexicana var. mexicana
Molecules 2011, 16(10), 8866-8873; https://doi.org/10.3390/molecules16108866
Received: 27 September 2011 / Revised: 17 October 2011 / Accepted: 18 October 2011 / Published: 21 October 2011
PDF Full-text (179 KB) | Supplementary Files
Abstract
From the aerial parts of Salvia mexicana var. mexicana, two C-10 epimers (α and β) of salvimexicanolide were isolated. Our interpretation of the data, especially the 13C NMR, led us to conclude that the previously described 13C-NMR spectrum of the
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From the aerial parts of Salvia mexicana var. mexicana, two C-10 epimers (α and β) of salvimexicanolide were isolated. Our interpretation of the data, especially the 13C NMR, led us to conclude that the previously described 13C-NMR spectrum of the α-epimer was not accurately assigned and it actually corresponds to the β-epimer. The structures proposed for the salvimexicanolides were verified by means of NOESY experiments. Dugesin B, arbutin, naringenin and the mixture of oleanolic and ursolic acids were also isolated from this Salvia spp. Full article
Open AccessArticle Transcriptional and Functional Analysis Shows Sodium Houttuyfonate-Mediated Inhibition of Autolysis in Staphylococcus aureus
Molecules 2011, 16(10), 8848-8865; https://doi.org/10.3390/molecules16108848
Received: 13 October 2011 / Accepted: 17 October 2011 / Published: 21 October 2011
Cited by 14 | PDF Full-text (305 KB) | Supplementary Files
Abstract
Sodium houttuyfonate (SH), an addition compound of sodium bisulfite and houttuynin, showed in vitro antibacterial activity against 21 Staphylococcus aureus (S. aureus) strains grown in planktonic cultures. Microarray results showed decreased levels of autolysin atl, sle1, cidA and
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Sodium houttuyfonate (SH), an addition compound of sodium bisulfite and houttuynin, showed in vitro antibacterial activity against 21 Staphylococcus aureus (S. aureus) strains grown in planktonic cultures. Microarray results showed decreased levels of autolysin atl, sle1, cidA and lytN transcripts in the SH-treated strain as compared to the control strain, consistent with the induction of the autolytic repressors lrgAB and sarA and with the downregulation of the positive regulators agrA and RNAIII. Triton X-100-induced autolysis was significantly decreased by SH in S. aureus ATCC 25923, and quantitative bacteriolytic assays and zymographic analysis demonstrated SH-mediated reduction of extracellular murein hydrolase activity in these cells. Anti-biofilm assay showed that SH is poorly active against S. aureus grown in biofilm cultures, whereas SH diminished the amounts of extracellular DNA (eDNA) of S. aureus in a dose-dependent manner, which suggested that SH may impede biofilm formation by reducing the expression of cidA to inhibit autolysis and eDNA release in the early phase. Some of the microarray results were confirmed by real-time RT-PCR. Full article
Open AccessArticle Components of Rhizome Extract of Cnidium officinale Makino and Their In vitro Biological Effects
Molecules 2011, 16(10), 8833-8847; https://doi.org/10.3390/molecules16108833
Received: 21 September 2011 / Revised: 13 October 2011 / Accepted: 18 October 2011 / Published: 21 October 2011
Cited by 18 | PDF Full-text (954 KB)
Abstract
The anti-inflammatory and anticancer activities of a methanol extract of the rhizome of Cnidium officinale were investigated. Four compounds, namely falcarindiol (1), 6-hydroxy-7-methoxy-dihydroligustilide (2), ligustilidiol (3), and senkyunolide H (4) were isolated from the extract
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The anti-inflammatory and anticancer activities of a methanol extract of the rhizome of Cnidium officinale were investigated. Four compounds, namely falcarindiol (1), 6-hydroxy-7-methoxy-dihydroligustilide (2), ligustilidiol (3), and senkyunolide H (4) were isolated from the extract of the rhizome of Cnidium officinale and their structures were elucidated by analysis of their spectroscopic data and by comparison with previously reported data. These compounds showed anti-inflammatory activities, measured as inhibition of nitric oxide (NO) release in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells, with IC50 values of 4.31 ± 5.22, 152.95 ± 4.23, 72.78 ± 5.13, and 173.42 ± 3.22 μM, respectively. They also inhibited inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA expression induced by LPS. Among these compounds, falcarindiol (1) was found to have anti-proliferative effect against MCF-7 human breast cancer cells by induction of a G0/G1 cell cycle block of the cells, with an IC50 value of 35.67 μM. Typical apoptotic effects were observed by phase contrast microscopy and were also exhibited in fluorescence microscopy with Hoechst 33342 staining. In addition, falcarindiol induced apoptosis through strongly increased mRNA expression of Bax and p53, and slightly reduced Bcl-2 mRNA levels in a dose dependent manner. This study suggested that C. officinale extract and its components would be valuable candidates in therapeutic applications for anti-inflammatory and anti-cancer agents. Full article
(This article belongs to the Section Natural Products Chemistry)
Open AccessArticle Studies on the Synthesis of DMAP Derivatives by Diastereoselective Ugi Reactions
Molecules 2011, 16(10), 8815-8832; https://doi.org/10.3390/molecules16108815
Received: 17 August 2011 / Revised: 11 October 2011 / Accepted: 12 October 2011 / Published: 20 October 2011
Cited by 14 | PDF Full-text (343 KB)
Abstract
Diastereoselective Ugi reactions of DMAP-based aldehydes with α-amino acids and tert-butyl isocyanide were examined. The reactions of 4-(dimethylamino)-2-pyridine-carboxaldehyde with various α-amino acids afforded 2-substituted DMAP derivatives with low diastereoselectivity. On the contrary, reactions with 4-(dimethylamino)-3-pyridine-carboxaldehyde delivered 3-substituted DMAP derivatives with moderate to
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Diastereoselective Ugi reactions of DMAP-based aldehydes with α-amino acids and tert-butyl isocyanide were examined. The reactions of 4-(dimethylamino)-2-pyridine-carboxaldehyde with various α-amino acids afforded 2-substituted DMAP derivatives with low diastereoselectivity. On the contrary, reactions with 4-(dimethylamino)-3-pyridine-carboxaldehyde delivered 3-substituted DMAP derivatives with moderate to high diastereoselectivity. The combination of α-amino acid and DMAP-based aldehyde is thus important to achieve high diastereoselectivity. Kinetic resolution of a secondary alcohol using a chiral DMAP derivative obtained through these reactions was also examined. Full article
(This article belongs to the Special Issue Multicomponent Reaction)
Open AccessArticle Microwave-Assisted Improved Synthesis of Oxazolidin-2-ones, Oxazolidine-2-thiones and Thiazolidine-2-thione Chiral Auxiliaries
Molecules 2011, 16(10), 8803-8814; https://doi.org/10.3390/molecules16108803
Received: 13 September 2011 / Revised: 7 October 2011 / Accepted: 18 October 2011 / Published: 20 October 2011
Cited by 9 | PDF Full-text (211 KB)
Abstract
A microwave assisted method for the synthesis of some typical 4-substituted oxazolidinone chiral auxiliaries used in asymmetric synthesis is reported in this work. Under these conditions, treatment of (S)-phenylalaninol, (S)-phenylglycinol, (S)-valinol and (1S, 2R
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A microwave assisted method for the synthesis of some typical 4-substituted oxazolidinone chiral auxiliaries used in asymmetric synthesis is reported in this work. Under these conditions, treatment of (S)-phenylalaninol, (S)-phenylglycinol, (S)-valinol and (1S, 2R)-norephedrine with ethyl carbonate or carbon disulfide under the appropriate and specific microwave reaction conditions, led to an efficient synthesis of some oxazolidin-2-ones, oxazolidine-2-thiones and thiazolidine-2-thiones. The methodology reported in this paper provides these chiral auxiliaries with improved yields and a remarkable reduction on the reaction times, particularly in the case of thiazolidine-2-thiones, as compared with the conventional methods. All the auxiliaries prepared here show spectroscopic data in full agreement with those previously reported in the literature. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
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Open AccessArticle Synthesis, Acidity Constants and Tautomeric Structure of the Diazonium Coupling Products of 2-(Benzylsulfanyl)-7H-purin-6-one in Its Ground and Excited States
Molecules 2011, 16(10), 8788-8802; https://doi.org/10.3390/molecules16108788
Received: 22 September 2011 / Revised: 7 October 2011 / Accepted: 12 October 2011 / Published: 19 October 2011
Cited by 7 | PDF Full-text (276 KB)
Abstract
A series of new 8-arylhydrazono-2-(benzylsulfanyl)-7H-purin-6-ones 6 were synthesized, their electronic absorption spectra in different organic solvents of varying polarities were investigated and their acid dissociation constants in both the ground and excited states were determined spectrophotometrically. The tautomeric structures of such
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A series of new 8-arylhydrazono-2-(benzylsulfanyl)-7H-purin-6-ones 6 were synthesized, their electronic absorption spectra in different organic solvents of varying polarities were investigated and their acid dissociation constants in both the ground and excited states were determined spectrophotometrically. The tautomeric structures of such products were elucidated by spectral analyses and correlation of their acid dissociation constants with the Hammett equation. The results indicated that the studied compounds 6 exist predominantly in the hydrazone tautomeric form 6A in both the ground and excited states. Full article
(This article belongs to the Special Issue Heterocycles)
Open AccessArticle Divergent Synthesis of Novel Five-Membered Heterocyclic Compounds by Base-Mediated Rearrangement of Acrylamides Derived from a Novel Isocyanide-Based Multicomponent Reaction
Molecules 2011, 16(10), 8775-8787; https://doi.org/10.3390/molecules16108775
Received: 21 September 2011 / Revised: 3 October 2011 / Accepted: 11 October 2011 / Published: 19 October 2011
Cited by 10 | PDF Full-text (237 KB)
Abstract
We have recently reported a novel multicomponent reaction between arylacetic acids and isocyanides, affording α-acyloxyacrylamides through an unusual mechanism. The products of this novel multicomponent reaction can rearrange to five membered heterocyclic compounds when exposed to an alkaline environment. Depending on the reaction
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We have recently reported a novel multicomponent reaction between arylacetic acids and isocyanides, affording α-acyloxyacrylamides through an unusual mechanism. The products of this novel multicomponent reaction can rearrange to five membered heterocyclic compounds when exposed to an alkaline environment. Depending on the reaction conditions and on the substitution pattern on the substrates, various pyrrolidine derivatives can be selectively obtained. We now wish to report that libraries endowed with skeletal diversity, thus responding to the requirements of Diversity Oriented Synthesis (DOS), can be efficiently prepared in this manner, and phenotypic biological assays have shown interesting properties of some representative compounds. Full article
(This article belongs to the Special Issue Multicomponent Reaction)
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Open AccessArticle Triazolobithiophene Light Absorbing Self-Assembled Monolayers: Synthesis and Mass Spectrometry Applications
Molecules 2011, 16(10), 8758-8774; https://doi.org/10.3390/molecules16108758
Received: 20 September 2011 / Revised: 10 October 2011 / Accepted: 17 October 2011 / Published: 19 October 2011
Cited by 3 | PDF Full-text (311 KB) | Supplementary Files
Abstract
The synthesis of five light absorbing triazolobithiophenic thiols, which were utilized for producing self-assembled monolayers (SAMs) on gold surfaces, is presented. The monolayer formation was monitored by cyclic voltammetry, indicating excellent surface coverage. The new triazolobithiophenic compounds exhibited an absorption maximum around 340
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The synthesis of five light absorbing triazolobithiophenic thiols, which were utilized for producing self-assembled monolayers (SAMs) on gold surfaces, is presented. The monolayer formation was monitored by cyclic voltammetry, indicating excellent surface coverage. The new triazolobithiophenic compounds exhibited an absorption maximum around 340 nm, which is close to the emission wavelength of a standard nitrogen laser. Consequently these compounds could be used to aid ionization in laser desorption mass spectrometry (MS). Full article
(This article belongs to the Section Natural Products Chemistry)
Open AccessArticle Facile Synthesis of Functionalized Spiropyrrolizidine Oxindoles via a Three-Component Tandem Cycloaddition Reaction
Molecules 2011, 16(10), 8745-8757; https://doi.org/10.3390/molecules16108745
Received: 26 August 2011 / Revised: 30 September 2011 / Accepted: 3 October 2011 / Published: 19 October 2011
Cited by 16 | PDF Full-text (323 KB) | Supplementary Files
Abstract
An efficient synthesis of functionalized spiropyrrolizidine oxindoles via a three-component tandem cycloaddition has been achieved. This strategy can provide direct and rapid access to spiropyrrolizidine oxindoles in high yields (up to 99%) with excellent diastereoselectivities (up to 99:1 dr). The features of this
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An efficient synthesis of functionalized spiropyrrolizidine oxindoles via a three-component tandem cycloaddition has been achieved. This strategy can provide direct and rapid access to spiropyrrolizidine oxindoles in high yields (up to 99%) with excellent diastereoselectivities (up to 99:1 dr). The features of this procedure are the following: mild reaction conditions, high yields, high diastereoselectivities, one-pot procedure and operational simplicity. Full article
(This article belongs to the Special Issue Heterocycles)
Open AccessArticle Efficient Microwave-Assisted Synthesis of Ionic Esterified Amino Acids
Molecules 2011, 16(10), 8733-8744; https://doi.org/10.3390/molecules16108733
Received: 16 September 2011 / Revised: 11 October 2011 / Accepted: 14 October 2011 / Published: 19 October 2011
Cited by 8 | PDF Full-text (226 KB)
Abstract
In this work, an efficient microwave-assisted methodology for the esterification of unprotected α-amino acids is described. Ionic esterified amino acids were synthesized in satisfactory yields in a facile one-pot solventless protocol from unprotected amino acids and alcohols under acid catalysis (MsOH or p
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In this work, an efficient microwave-assisted methodology for the esterification of unprotected α-amino acids is described. Ionic esterified amino acids were synthesized in satisfactory yields in a facile one-pot solventless protocol from unprotected amino acids and alcohols under acid catalysis (MsOH or p-TsOH) to afford the pure products after a simple work-up procedure. This procedure can also be extended to the preparation of long and short chain alkyl and benzyl esters. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
Open AccessReview Alkaloids from Marine Ascidians
Molecules 2011, 16(10), 8694-8732; https://doi.org/10.3390/molecules16108694
Received: 16 September 2011 / Revised: 11 October 2011 / Accepted: 14 October 2011 / Published: 19 October 2011
Cited by 27 | PDF Full-text (601 KB)
Abstract
About 300 alkaloid structures isolated from marine ascidians are discussed in term of their occurrence, structural type and reported pharmacological activity. Some major groups (e.g., the lamellarins and the ecteinascidins) are discussed in detail, highlighting their potential as therapeutic agents for the treatment
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About 300 alkaloid structures isolated from marine ascidians are discussed in term of their occurrence, structural type and reported pharmacological activity. Some major groups (e.g., the lamellarins and the ecteinascidins) are discussed in detail, highlighting their potential as therapeutic agents for the treatment of cancer or viral infections. Full article
(This article belongs to the Section Natural Products Chemistry)
Open AccessArticle Hepatoprotective Action of Radix Paeoniae Rubra Aqueous Extract against CCl4-Induced Hepatic Damage
Molecules 2011, 16(10), 8684-8693; https://doi.org/10.3390/molecules16108684
Received: 30 August 2011 / Revised: 7 October 2011 / Accepted: 11 October 2011 / Published: 17 October 2011
Cited by 15 | PDF Full-text (183 KB)
Abstract
In the present study the capacity of Radix Paeoniae Rubra aqueous extract (RPRAE) as an antioxidant to protect against carbon tetrachloride (CCl4)-induced oxidative stress and hepatotoxicity in Wistar rats was investigated. Six groups of rats were used. Radix Paeoniae Rubra aqueous
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In the present study the capacity of Radix Paeoniae Rubra aqueous extract (RPRAE) as an antioxidant to protect against carbon tetrachloride (CCl4)-induced oxidative stress and hepatotoxicity in Wistar rats was investigated. Six groups of rats were used. Radix Paeoniae Rubra aqueous extract (100 or 200 or 300 mg/kg of bw) or bifendate (100 mg/kg of bw) were given daily by gavage to the animals on 28 consecutive days to elucidate the protective effects against CCl4-induced hepatotoxicity. The 20% CCl4/olive oil was gavage of gastric tube twice a week (on the third and seventh days of each week). The animals of normal control group were given only vehicle. The animals of CCl4-treated group were administered with CCl4 twice a week (on the third and seventh days of each week) and with vehicle on rest of the days. The test materials were found effective as hepatoprotective agents, as evidenced by plasma and liver biochemical parameters. Therefore, the results of this study show that Radix Paeoniae Rubra aqueous extract can protect the liver against CCl4-induced oxidative damage in rats, and the hepatoprotective effects might be correlated with its antioxidant and free radical scavenger effects. Full article
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