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Molecules, Volume 14, Issue 11 (November 2009), Pages 4300-4803

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Open AccessArticle Silibinin Suppresses TNF-α-Induced MMP-9 Expression in Gastric Cancer Cells through Inhibition of the MAPK Pathway
Molecules 2009, 14(11), 4300-4311; doi:10.3390/molecules14114300
Received: 7 September 2009 / Revised: 10 October 2009 / Accepted: 19 October 2009 / Published: 26 October 2009
Cited by 20 | PDF Full-text (310 KB)
Abstract
Tumor necrosis factor (TNF)-α is one of the pro-inflammatory cytokines highly expressed in Helicobacter pylori that inhibits gastric acid secretion. In this study we determined the effect of silibinin on TNF-α-induced MMP-9 expression in gastric cancer cell lines. MMP-9 mRNA and protein [...] Read more.
Tumor necrosis factor (TNF)-α is one of the pro-inflammatory cytokines highly expressed in Helicobacter pylori that inhibits gastric acid secretion. In this study we determined the effect of silibinin on TNF-α-induced MMP-9 expression in gastric cancer cell lines. MMP-9 mRNA and protein expression was dose-dependently increased by TNF-α in SNU216 and SNU668 gastric cancer cells. On the other hand, TNF-α-induced MMP-9 expression was dose-dependently suppressed by silibinin. To verify the regulatory mechanism of silibinin on TNF-α-induced MMP-9 expression, the gastric cancer cell lines were pretreated with silibinin prior to TNF-α. TNF-α-induced MMP-9 expression was inhibited by the MEK1/2 specific inhibitor, UO126. Finally, we investigated the effect of adenoviral constitutively active (CA)-MEK and CA-Akt on MMP-9 expression. The expression of MMP-9 was significantly increased by CA-MEK overexpression, but not by CA-Akt overexpression. Taken together, we suggest that silibinin down-regulates TNF-α- induced MMP-9 expression through inhibition of the MEK/ERK pathway in gastric cancer cells. Full article
Open AccessArticle Synthesis and Characterization of Some Chiral Metal-Salen Complexes Bearing a Ferrocenophane Substituent
Molecules 2009, 14(11), 4312-4325; doi:10.3390/molecules14114312
Received: 3 September 2009 / Revised: 13 October 2009 / Accepted: 22 October 2009 / Published: 26 October 2009
Cited by 11 | PDF Full-text (614 KB)
Abstract
The C2-symmetrical “salen” ligand (+)-9 bearing two [5]ferrocenophane substituents has been prepared in five steps starting from readily available diacetylferrocene, p-hydroxybenzaldehyde and (R,R)-N,N’-diphenylethylenediamine. Reaction of (+)-9 with Mn(OAc)3, Co(OAc) [...] Read more.
The C2-symmetrical “salen” ligand (+)-9 bearing two [5]ferrocenophane substituents has been prepared in five steps starting from readily available diacetylferrocene, p-hydroxybenzaldehyde and (R,R)-N,N’-diphenylethylenediamine. Reaction of (+)-9 with Mn(OAc)3, Co(OAc)2 ZnEt2 or UO2(OAc)2 gave the corresponding metal-complexes which were characterised by spectroscopic methods. Full article
(This article belongs to the Special Issue Ferrocenes)
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Open AccessArticle Towards the Synthesis of Inosine Building Blocks for the Preparation of Oligonucleotides with Hydrophobic Alkyl Chains Between the Nucleotide Units
Molecules 2009, 14(11), 4326-4336; doi:10.3390/molecules14114326
Received: 18 September 2009 / Revised: 19 October 2009 / Accepted: 23 October 2009 / Published: 26 October 2009
Cited by 6 | PDF Full-text (209 KB)
Abstract
The scientific objective of the research reported in this manuscript was the synthesis of novel phosphoramidite building blocks for the preparation of lipophilic oligonucleotides. Reaction of inosine (4) with 4-oxopentyl-4-methylbenzoate (2c) in the presence of triethyl orthoformate and 4M HCl in 1,4-dioxane [...] Read more.
The scientific objective of the research reported in this manuscript was the synthesis of novel phosphoramidite building blocks for the preparation of lipophilic oligonucleotides. Reaction of inosine (4) with 4-oxopentyl-4-methylbenzoate (2c) in the presence of triethyl orthoformate and 4M HCl in 1,4-dioxane gave a diastereoisomeric mixture of the ketals 5. Subsequent 4,4’-dimethoxytritylation at the 5’-hydroxyl afforded (R)-6 + (S)-6 which could be separated chromatographically. Detoluoylation gave compounds (R)-7 and (S)-7. Phosphitylation of a diastereoisomeric mixture of 7 led to a mixture of four diastereoisomers of the corresponding 2-cyanoethylphosphoramidites 8. Full article
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Open AccessArticle Oxidative Desulfurization of Fuel Oil by Pyridinium-Based Ionic Liquids
Molecules 2009, 14(11), 4351-4357; doi:10.3390/molecules14114351
Received: 9 September 2009 / Revised: 8 October 2009 / Accepted: 19 October 2009 / Published: 28 October 2009
Cited by 31 | PDF Full-text (93 KB)
Abstract
In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF4 was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The [...] Read more.
In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF4 was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF4 has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H2O2) = 1:1:0.4, temperature 55 °C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration. Full article
(This article belongs to the Special Issue Ionic Liquids)
Open AccessArticle Influence of Ripeness and Drying Process on the Polyphenols and Tocopherols of Pistacia vera L.
Molecules 2009, 14(11), 4358-4369; doi:10.3390/molecules14114358
Received: 28 September 2009 / Revised: 29 October 2009 / Accepted: 30 October 2009 / Published: 30 October 2009
Cited by 18 | PDF Full-text (217 KB)
Abstract
This paper highlights, for the first time, the changes in the phenolics fraction (anthocyanins, flavonoids and stilbenes) and tocopherols of unpeeled Pistacia vera L. var. bianca with ripening, and the effect of the sun-drying process. The total polyphenol levels in pistachios, measured [...] Read more.
This paper highlights, for the first time, the changes in the phenolics fraction (anthocyanins, flavonoids and stilbenes) and tocopherols of unpeeled Pistacia vera L. var. bianca with ripening, and the effect of the sun-drying process. The total polyphenol levels in pistachios, measured as mg of Gallic Acid Equivalent (GAE), were: 201 ± 10.1, 349 ± 18.3 and 184.7 ± 6.2 mg GAE/100 g DM in unripe, ripe and dried ripe samples, respectively. Most phenolics in ripe pistachios were found to be anthocyanins. They increased with ripening, while the sun drying process caused a susbtantial loss. Flavonoids found in all pistachio samples were daidzein, genistein, daidzin, quercetin, eriodictyol, luteolin, genistin and naringenin, which decreased both with ripening and drying. Before the drying process both unripe and ripe pistachios showed a higher content of trans-resveratrol than dried ripe samples. γ-Tocopherol was the major vitamin E isomer found in pistachios. The total content (of α- and γ-tocopherols) decreased, both during ripening and during the drying process. These results suggested that unpeeled pistachios can be considered an important source of phenolics, particularly of anthocyanins. Moreover, in order to preserve these healthy characteristics, new and more efficient drying processes should be adopted. Full article
Open AccessArticle Characterization and Dissolution Study of Chitosan Freeze-Dried Systems for Drug Controlled Release
Molecules 2009, 14(11), 4370-4386; doi:10.3390/molecules14114370
Received: 8 September 2009 / Revised: 14 October 2009 / Accepted: 28 October 2009 / Published: 30 October 2009
Cited by 14 | PDF Full-text (768 KB)
Abstract
Freeze-dried systems (L) comprising chitosan (CS) and caffeine (CAF) have been developed for oral administration. Different proportions of CS and CAF have been used in the preparation of the systems. Hot stage microscopy (HSM), differential scanning calorimetry (DSC) and X-ray diffraction powder [...] Read more.
Freeze-dried systems (L) comprising chitosan (CS) and caffeine (CAF) have been developed for oral administration. Different proportions of CS and CAF have been used in the preparation of the systems. Hot stage microscopy (HSM), differential scanning calorimetry (DSC) and X-ray diffraction powder have been used to characterize the systems prepared. X-ray diffraction patterns showed that there were no interactions between CAF and CS molecules within the freeze-dried systems and the crystallinity of CAF was decreased. Swelling and dissolution tests were carried out in two different media (demineralized water and pH progressive medium) in order to establish their influence over CAF/CS system behaviour. Characteristic swelling behaviour of freeze-dried CS systems (imbibition and dissolution processes) was influenced by the proportions of CS and CAF in the formulations, and by the nature of the medium due to the pH-dependent solubility of CS. Release of CAF from lyophilized systems was conditioned by the swelling process and it should be possible to obtain a CAF/CS binary system with a specific time for total drug release including concrete proportions of both components. Furthermore, the freeze-drying process allowed us to obtain feasible systems for controlled release of CAF until the total amount of drug was released. Full article
(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutics)
Open AccessCommunication Apolar Annonaceous Acetogenins from the Fruit Pulp of Annona muricata
Molecules 2009, 14(11), 4387-4395; doi:10.3390/molecules14114387
Received: 22 September 2009 / Revised: 19 October 2009 / Accepted: 22 October 2009 / Published: 2 November 2009
Cited by 10 | PDF Full-text (298 KB)
Abstract
A methylene chloride extract of the pulp of Annona muricata L. was fractionated in search for scarcely functionalized Annonaceous acetogenins (type E). Previously known C-35 and C-37 mono-epoxy unsaturated compounds, epomuricenins-A and -B (1+2) and epomusenins-A and -B (3+4), were obtained. Two [...] Read more.
A methylene chloride extract of the pulp of Annona muricata L. was fractionated in search for scarcely functionalized Annonaceous acetogenins (type E). Previously known C-35 and C-37 mono-epoxy unsaturated compounds, epomuricenins-A and -B (1+2) and epomusenins-A and -B (3+4), were obtained. Two new mono-epoxy saturated C-35 representatives, epomurinins-A and -B (5+6) were also isolated. Full article
(This article belongs to the Special Issue Acetogenins: Extraction, Synthesis and Biological Properties)
Open AccessArticle 1-Methyl-3-octylimidazolium Chloride—Sorption and Primary Biodegradation Analysis in Activated Sewage Sludge
Molecules 2009, 14(11), 4396-4405; doi:10.3390/molecules14114396
Received: 30 August 2009 / Revised: 28 October 2009 / Accepted: 30 October 2009 / Published: 2 November 2009
Cited by 18 | PDF Full-text (158 KB)
Abstract
Ionic liquids (ILs) are known to be non-volatile and thus to have low potential for atmospheric contamination or intoxication of humans by inhalation. However ILs have the potential to contaminate soil and water as they might be water soluble and can be [...] Read more.
Ionic liquids (ILs) are known to be non-volatile and thus to have low potential for atmospheric contamination or intoxication of humans by inhalation. However ILs have the potential to contaminate soil and water as they might be water soluble and can be sorbed onto solids. The investigation of possible natural ways of reducing the concentration of ILs in the environment is of high importane, especially because the requirement for biodegradable chemicals increases, together with pressure for reduction of incineration and landfill waste. It was found that the upper concentration threshold for primary biodegradation of 1-methyl-3-octylimidazolium chloride is 0.2 mM. At higher concentrations the dehydrogenase activity of the cells dropped markedly, indicating that the IL inhibits cell activity. This concentration is in good agreement with the minimal inhibitory concentration of the same compound found for a series of bacteria and fungi by this research group. The sorption of 1-methyl-3-octylimidazolium chloride was found to be significant, and the sorption coefficient was determined to be 98.2 L kg-1. Full article
(This article belongs to the Special Issue Ionic Liquids)
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Open AccessArticle Studies with Azinylacetonitriles: 2-Pyridylacetonitrile as a Precursor to Functionally Substituted Pyridines
Molecules 2009, 14(11), 4406-4413; doi:10.3390/molecules14114406
Received: 7 September 2009 / Revised: 27 October 2009 / Accepted: 28 October 2009 / Published: 3 November 2009
Cited by 2 | PDF Full-text (132 KB)
Abstract
2-Pyridylacetonitrile (1) couples with aromatic diazonium salts to yield arylhydrazones 2a-c, that were shown to exist in the syn-form 2 rather than the anti-form 4. Compounds 2a,c reacted with hydroxylamine in refluxing DMF to yield the interesting 1,2,3-triazolylpyridines 6. Attempts [...] Read more.
2-Pyridylacetonitrile (1) couples with aromatic diazonium salts to yield arylhydrazones 2a-c, that were shown to exist in the syn-form 2 rather than the anti-form 4. Compounds 2a,c reacted with hydroxylamine in refluxing DMF to yield the interesting 1,2,3-triazolylpyridines 6. Attempts to cyclize 2 to give the corresponding fused pyrazolopyridines 9 failed. On the other hand, compound 1 condensed with dimethylformamide dimethyl acetal to yield enaminonitrile 10 that could be converted into pyrazolylpyridine 11. Full article
Open AccessArticle Bioactive Azafluorenone Alkaloids from Polyalthia debilis (Pierre) Finet & Gagnep.
Molecules 2009, 14(11), 4414-4424; doi:10.3390/molecules14114414
Received: 15 September 2009 / Revised: 21 October 2009 / Accepted: 2 November 2009 / Published: 3 November 2009
Cited by 23 | PDF Full-text (268 KB)
Abstract
This study investigated bioactive extracts of Polyalthia debilis (Annonaceae) with antimicrobial, antimalarial and cytotoxic activities. Extensive chromatographic isolations provided azafluorenone alkaloids; onychine (1) and 7-methoxyonychine (2) together with a mixture of β–sitosterol and stigmasterol. The two alkaloids were isolated from the [...] Read more.
This study investigated bioactive extracts of Polyalthia debilis (Annonaceae) with antimicrobial, antimalarial and cytotoxic activities. Extensive chromatographic isolations provided azafluorenone alkaloids; onychine (1) and 7-methoxyonychine (2) together with a mixture of β–sitosterol and stigmasterol. The two alkaloids were isolated from the P. debilis for the first time. Isolated fractions containing a mixture of triterpenoids (C7, C8 and C9) exhibited the most potent antimicrobial activity against many bacterial strains with minimum inhibitory concentration of 64 μg/mL. Fractions with antimalarial and cytotoxic activities were also observed. The findings suggest the potential use of P. debilis in medicinal applications. Full article
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Open AccessCommunication Depigmenting Effect of Catechins
Molecules 2009, 14(11), 4425-4432; doi:10.3390/molecules14114425
Received: 24 September 2009 / Revised: 29 October 2009 / Accepted: 2 November 2009 / Published: 4 November 2009
Cited by 11 | PDF Full-text (737 KB)
Abstract
The aim of the present work was to clarify the anti-melanogenic mechanism of the catechin group. In this study, we used (-)-epigallocatechin-3-gallate (EGCG), (-)-epigallocatechin (EGC), (-)-catechin (C), and gallic acid (GA). The catechin group inhibited melanin synthesis in B16 melanoma cells. To [...] Read more.
The aim of the present work was to clarify the anti-melanogenic mechanism of the catechin group. In this study, we used (-)-epigallocatechin-3-gallate (EGCG), (-)-epigallocatechin (EGC), (-)-catechin (C), and gallic acid (GA). The catechin group inhibited melanin synthesis in B16 melanoma cells. To elucidate the anti-melanogenic mechanism of the catechin group, we performed Western blotting analysis for crucial melanogenic protein, namely tyrosinase. The catechin group inhibited tyrosinase expression. These results indicate that the catechin group is a candidate anti-melanogenic agent and that it might be effective in hyperpigmentation disorders. Full article
Open AccessCommunication Chemical Constituents from Clematis delavayi var. spinescens
Molecules 2009, 14(11), 4433-4439; doi:10.3390/molecules14114433
Received: 20 October 2009 / Revised: 29 October 2009 / Accepted: 30 October 2009 / Published: 5 November 2009
Cited by 10 | PDF Full-text (196 KB)
Abstract
A new coumarin, 7-hydroxy-4,6-dimethoxy-5-methylcoumarin (1), was isolated from the aerial parts of Clematis delavayi var. spinescens together with 17 known compounds. Their structures were identified by extensive spectral analysis, especially 2D NMR techniques. Antiangiogenic effects of all compounds were evaluated using a [...] Read more.
A new coumarin, 7-hydroxy-4,6-dimethoxy-5-methylcoumarin (1), was isolated from the aerial parts of Clematis delavayi var. spinescens together with 17 known compounds. Their structures were identified by extensive spectral analysis, especially 2D NMR techniques. Antiangiogenic effects of all compounds were evaluated using a zebrafish model. Full article
Open AccessArticle The Effect of Long-Running Severe Selenium-Deficiency on the Amount of Iron and Zinc in the Organs of Rats
Molecules 2009, 14(11), 4440-4453; doi:10.3390/molecules14114440
Received: 5 October 2009 / Revised: 2 November 2009 / Accepted: 4 November 2009 / Published: 5 November 2009
Cited by 3 | PDF Full-text (275 KB)
Abstract
The amounts of selenium (Se), iron (Fe), and zinc (Zn) in the liver, kidney, and spleen as a function of age of rats measured using instrumental neutron activation analysis were compared between Se-deficient (SeD) rats and normal rats. The SeD model rats [...] Read more.
The amounts of selenium (Se), iron (Fe), and zinc (Zn) in the liver, kidney, and spleen as a function of age of rats measured using instrumental neutron activation analysis were compared between Se-deficient (SeD) rats and normal rats. The SeD model rats can live for more than 50 weeks. The effect of Se-deficinecy in rats might be weak, compared to the marked malfunction of GSH-Px. The SeD rats can be considered as a model of nonlethal chronic oxidative stress. Fluctuations of Fe and Zn in the liver of Se-deficient rats were observed. The amount of redox-relating minerals, such as Fe and Zn, in SeD rat organs is changeable depending on the age. Full article
(This article belongs to the Special Issue Selenium and Tellurium Chemistry)
Open AccessArticle In Vitro Antioxidant and Xanthine Oxidase Inhibitory Activities of Methanolic Swietenia mahagoni Seed Extracts
Molecules 2009, 14(11), 4476-4485; doi:10.3390/molecules14114476
Received: 4 September 2009 / Revised: 10 October 2009 / Accepted: 27 October 2009 / Published: 6 November 2009
Cited by 32 | PDF Full-text (272 KB)
Abstract
This study examines the in vitro antioxidant activities of the methanol extract of Swietenia mahagoni seeds (SMCM seed extract). The extract was screened for possible antioxidant activities by free radical scavenging activity (DPPH), xanthine oxidase inhibition (XOI), hydrogen peroxide scavenging activity (HPSA) [...] Read more.
This study examines the in vitro antioxidant activities of the methanol extract of Swietenia mahagoni seeds (SMCM seed extract). The extract was screened for possible antioxidant activities by free radical scavenging activity (DPPH), xanthine oxidase inhibition (XOI), hydrogen peroxide scavenging activity (HPSA) and ferric-reducing antioxidant power (FRAP) assays. The total phenolic and flavonoid contents were also determined. The extract exhibits antioxidant activity of 23.29% with an IC50 value of 2.3 mg/mL in the DPPH radical scavenging method, 47.2% in the XOI assay, 49.5% by the HPSA method, and 0.728 mmol/Fe(II)g in the FRAP method at the concentration tested. The amount of total phenolics and flavonoid contents was 70.83 mg gallic acid equivalent (GAE) and 2.5 ± 0.15 mg of catechin equivalent per gram of dry extract, respectively. High Performance Thin Layer Chromatography (HPTLC) screening indicates the presence of phenolic compounds in the SMCM seed extract. The results indicate that the extract has both high free radical scavenging and xanthine oxidase inhibition activity. The antioxidant activity of SMCM seed extract is comparable with that of other Malaysian tropical fruits and herbal plants. Full article
Open AccessArticle A Selective Pharmacophore Model for β2-Adrenoceptor Agonists
Molecules 2009, 14(11), 4486-4496; doi:10.3390/molecules14114486
Received: 23 September 2009 / Revised: 22 October 2009 / Accepted: 29 October 2009 / Published: 6 November 2009
Cited by 2 | PDF Full-text (338 KB)
Abstract
β2-Adrenoceptor selectivity is an important consideration in drug design in order to minimize the possibility of side effects. A selective pharmacophore model was developed based on a series of selective β2-adrenoceptor agonists. The best pharmacophore hypothesis consisted of [...] Read more.
β2-Adrenoceptor selectivity is an important consideration in drug design in order to minimize the possibility of side effects. A selective pharmacophore model was developed based on a series of selective β2-adrenoceptor agonists. The best pharmacophore hypothesis consisted of five chemical features (one hydrogen-bond acceptor, one hydrogen-bond donor, two ring aromatic and one positive ionizable feature). The result was nearly in accordance with the reported interactions between the β2-adrenoceptor and agonists, and it shared enough similar features with the result of field point patterns by FieldTemplater, which mainly validated the pharmacophore model. Moreover, the pharmacophore could predict the selectivity over the β1-adrenoceptor. These results might provide guidance for the rational design of novel potent and selective β2-adrenoceptor agonists. Full article
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Open AccessCommunication A New Triterpene Hexaglycoside from the Bark of Kalopanax septemlobus (Thunb.) Koidz.
Molecules 2009, 14(11), 4497-4504; doi:10.3390/molecules14114497
Received: 10 September 2009 / Revised: 21 October 2009 / Accepted: 23 October 2009 / Published: 9 November 2009
Cited by 4 | PDF Full-text (149 KB)
Abstract
The new triterpene glycoside 3-O-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosylhederagenin 28-O-β-D-gluco-pyranosyl-(1→6)-β-D-glucopyranoside, named septemoside A (1), and the known 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside-28-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester of hederagenin (2), were isolated from the bark of Kalopanax septemlobus. The structure elucidation [...] Read more.
The new triterpene glycoside 3-O-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosylhederagenin 28-O-β-D-gluco-pyranosyl-(1→6)-β-D-glucopyranoside, named septemoside A (1), and the known 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside-28-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester of hederagenin (2), were isolated from the bark of Kalopanax septemlobus. The structure elucidation of the compounds was based on spectroscopic evidence, including HRESIMS, 1D and 2D-NMR analysis. Full article
Open AccessArticle Antioxidant Effects of Some Drugs on Immobilization Stress Combined with Cold Restraint Stress
Molecules 2009, 14(11), 4505-4516; doi:10.3390/molecules14114505
Received: 7 September 2009 / Revised: 20 October 2009 / Accepted: 9 November 2009 / Published: 10 November 2009
Cited by 9 | PDF Full-text (354 KB)
Abstract
The aim of this work was to investigate the effect on antioxidant potential of some commonly used drugs (morphine, tramadol, bromocriptine, haloperidol and azithromycin) on immobilization stress (IS) combined with cold restraint stress (CRS) in the rat. After the drug treatment the [...] Read more.
The aim of this work was to investigate the effect on antioxidant potential of some commonly used drugs (morphine, tramadol, bromocriptine, haloperidol and azithromycin) on immobilization stress (IS) combined with cold restraint stress (CRS) in the rat. After the drug treatment the animals were kept immobilized in the cold chamber at 4±0.3ºC for 3 hours and then decapitaed and the livers were extracted. The following parameters were determined in the liver homogenate: content of reduced glutathione, activities of catalase, xanthine oxidase, glutathione reductase, glutathione peroxidase, peroxidase, and lipid peroxidation intensity. A battery of biochemical assays was used and the resulting data were statistically analyzed. Combined stress exhibited a prooxidative action (increased catalase activity, lowered content of reduced glutathione). Significantly enhanced catalase activity that was observed in all groups compared to the control indicates that the primary reactive oxygen species (ROS) metabolite is hydrogen peroxide, which decomposes very rapidly (very high catalase activity), thus hindering formation of OH radicals as the most toxic ROS. None of the tested drugs showed a protective effect on combined IS and CRS. The intensity of lipid peroxidation did not change either in the combined stress or under additional influence of the drugs. Probably, under our experimental conditions, the time was not sufficiently long to observe damage of lipid membrane by ROS. Full article
Open AccessArticle A New Norsesquiterpenoid from a Bornean Soft Coral Genus Nephthea
Molecules 2009, 14(11), 4591-4596; doi:10.3390/molecules14114591
Received: 25 September 2009 / Revised: 21 October 2009 / Accepted: 23 October 2009 / Published: 10 November 2009
Cited by 9 | PDF Full-text (63 KB)
Abstract A new germacrane-type norsesquiterpenoid, 1-acetoxy-germacra-5E,10(14)-diene-4-one (1), as well as three known compounds, were isolated from the organic extracts of a Bornean soft coral Nephthea sp. Their structures were elucidated on the basis of spectroscopic data analysis. Full article
Open AccessArticle Headspace Volatile Composition of the Flowers of Caralluma europaea N.E.Br. (Apocynaceae)
Molecules 2009, 14(11), 4597-4613; doi:10.3390/molecules14114597
Received: 16 October 2009 / Revised: 7 November 2009 / Accepted: 10 November 2009 / Published: 11 November 2009
Cited by 8 | PDF Full-text (221 KB)
Abstract
The volatile constituents of the flowers of Caralluma europaea (Guss.) N.E.Br (Apocynaceae) from Lampedusa Island were analyzed by a headspace GC method. The analyses allowed the identification and quantification of 41 compounds. The main components were, among the monoterpenoids, terpinolene (23.3%), α-terpinene [...] Read more.
The volatile constituents of the flowers of Caralluma europaea (Guss.) N.E.Br (Apocynaceae) from Lampedusa Island were analyzed by a headspace GC method. The analyses allowed the identification and quantification of 41 compounds. The main components were, among the monoterpenoids, terpinolene (23.3%), α-terpinene (19.1%) and linalool (18.4%), whereas, among the carbonylic compounds the major constituents were heptanal (2.0%), octanoic acid (2.4%) and hexanoic acid (1.7%). The presence of a nitrogen containing compound, indole (0.8%) and of a sulphur containing compound, dimethylsulphide (t), noteworthy. The compounds found in the flowers of C. europaea have been compared with data available in the literature as regard to their odor, presence in other sapromyiophilous taxa, possible role as semiochemicals, and presence in decaying organic matter. 89.3% of total constituents have been described in other sapromyiophilous taxa. Some of the compounds are present in several types of decaying organic matter (excrements, decomposing bodies, and spoiled fish, etc). Several volatiles found in C. europaea flowers are used as semiochemicals by Hymenoptera, Coleoptera, Diptera, Lepidoptera and other insects. Sixteen volatiles, accounting for 32.4% of the total constituents, are described as attractants of some Diptera families, with a biology linked to decaying organic matter. Our data thus confirm that C. europaea floral bouquet falls within the sapromyiophilous pollination syndrome. Full article
Open AccessArticle Chemical Composition and Antimicrobial Activity of the Essential Oils from Two Species of Thymus Growing Wild in Southern Italy
Molecules 2009, 14(11), 4614-4624; doi:10.3390/molecules14114614
Received: 15 October 2009 / Revised: 9 November 2009 / Accepted: 11 November 2009 / Published: 12 November 2009
Cited by 20 | PDF Full-text (145 KB)
Abstract
The volatile constituents of the aerial parts of two samples of Thymus longicaulis C. Presl, collected in Campania and in Sicily, and two samples of Thymus pulegioides L. from the same regions, were extracted by hydrodistillation and analyzed. Considering the four oils [...] Read more.
The volatile constituents of the aerial parts of two samples of Thymus longicaulis C. Presl, collected in Campania and in Sicily, and two samples of Thymus pulegioides L. from the same regions, were extracted by hydrodistillation and analyzed. Considering the four oils together, seventy-eight different compounds were identified: 57 for Thymus longicaulis from Sicily (91.1% of the total oil), 40 for Thymus longicaulis from Campania (91.5% of the oil), 39 for Thymus pulegioides from Sicily (92.5% of the oil) and 29 for Thymus pulegioides from Campania (90.1% of the oil). The composition of the oils is different, although the most abundant components are identical in T. pulegioides. The essential oils showed antibacterial activity against eight selected microorganisms. Full article
Open AccessCommunication Study of the Chemical Composition of the Resinous Exudate Isolated from Heliotropium Sclerocarpum and Evaluation of the Antioxidant Properties of the Phenolic Compounds and the Resin
Molecules 2009, 14(11), 4625-4633; doi:10.3390/molecules14114625
Received: 28 August 2009 / Revised: 31 October 2009 / Accepted: 11 November 2009 / Published: 12 November 2009
Cited by 13 | PDF Full-text (278 KB)
Abstract
Heliotropium sclerocarpum Phil. (Heliotropiaceae) is a resinous bush that grows in the Atacama of northern Chile. The chemical composition of its resinous exudate was analyzed for the first time. One aromatic geranyl derivative: filifolinol (1), one flavanone: naringenin (2) and [...] Read more.
Heliotropium sclerocarpum Phil. (Heliotropiaceae) is a resinous bush that grows in the Atacama of northern Chile. The chemical composition of its resinous exudate was analyzed for the first time. One aromatic geranyl derivative: filifolinol (1), one flavanone: naringenin (2) and a new type of 3-oxo-2-arylbenzofuran derivative 3 were isolated and their structures were determined. The antioxidant activity of the phenolic compounds and resin was evaluated using the bleaching of DPPH radical method and expressed as fast reacting equivalents (FRE) and total reacting equivalents (TRE). Full article
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Open AccessArticle 3-(2-Aminophenyl)-4-methyl-1,3-thiazole-2(3H)-thione as an Ecofriendly Sulphur Transfer Agent to Prepare Alkanethiols in High Yield and High Purity
Molecules 2009, 14(11), 4634-4643; doi:10.3390/molecules14114634
Received: 29 October 2009 / Revised: 10 November 2009 / Accepted: 11 November 2009 / Published: 12 November 2009
Cited by 4 | PDF Full-text (239 KB)
Abstract
A new process is described for preparing very pure linear alkanethiols and linear α,ω-alkanedithiols using a sequential alkylation of the title compound, followed by a ring closure to quantitatively give the corresponding 3-methyl[1,3]thiazolo[3,2-a]-[3,1]benzimidazol-9-ium salt and the alkanethiol derivative under mild conditions. The [...] Read more.
A new process is described for preparing very pure linear alkanethiols and linear α,ω-alkanedithiols using a sequential alkylation of the title compound, followed by a ring closure to quantitatively give the corresponding 3-methyl[1,3]thiazolo[3,2-a]-[3,1]benzimidazol-9-ium salt and the alkanethiol derivative under mild conditions. The alkanethiol and the heteroaromatic salt are easily separated by a simple extraction process. The intermediate thiazolium quaternary salts resulting from the first reaction step can be isolated in quantitative yields, affording an odourless protected form of the thiols. Full article
(This article belongs to the Special Issue Advances in Heteroaromatic Chemistry)
Open AccessArticle High-Performance Liquid Chromatographic Quantification of Flavonoids in Eriocaulaceae Species and Their Antimicrobial Activity
Molecules 2009, 14(11), 4644-4654; doi:10.3390/molecules14114644
Received: 9 October 2009 / Revised: 13 November 2009 / Accepted: 16 November 2009 / Published: 16 November 2009
Cited by 3 | PDF Full-text (163 KB)
Abstract
Quantification of prepared samples by analysis using high performance liquid chromatography with DAD detection was developed to analyze rutin, 6-methoxyapigenin, and 6-methoxyapigenin-7-O-β-D-glucopyranoside isolated from methanolic extracts of different genus: Syngonanthus, Leiothix and Eriocaulon (Eriocaulaceae). The linearity, accuracy, and the [...] Read more.
Quantification of prepared samples by analysis using high performance liquid chromatography with DAD detection was developed to analyze rutin, 6-methoxyapigenin, and 6-methoxyapigenin-7-O-β-D-glucopyranoside isolated from methanolic extracts of different genus: Syngonanthus, Leiothix and Eriocaulon (Eriocaulaceae). The linearity, accuracy, and the inter-day precision of the procedure were evaluated. The calibration curves were linear. The recoveries of the flavonoids in the samples analyzed were 96.3% to 98.5%. The percentage coefficient of variation for the quantitative analysis of the flavonoids in the analyses of the samples was under 5%. The antimicrobial activity of the five methanol extracts of these Eriocaulaceae species was assayed against the microorganisms Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Salmonella setubal, Saccharomyces cerevisiae and Candida albicans. Measured MIC values ranged from 1.25 to 10.00 mg/mL. The flavonoid contents suggest that Eriocaulaceae species may be a promising source of compounds to produce natural phytomedicines. Full article
Open AccessArticle Synthesis of Pregnane Derivatives, Their Cytotoxicity on LNCap and PC-3 Cells, and Screening on 5α-Reductase Inhibitory Activity
Molecules 2009, 14(11), 4655-4668; doi:10.3390/molecules14114655
Received: 8 September 2009 / Revised: 4 November 2009 / Accepted: 8 November 2009 / Published: 17 November 2009
Cited by 9 | PDF Full-text (572 KB)
Abstract
A series of epoxy- and/or 20-oxime pregnanes were synthesized from commercially available pregnenolone. Compounds 1, 3, 7, 8 and 11-13 were evaluated for cytotoxicity activity towards LNCaP (androgen-dependent) and PC-3 (androgenindependent) prostate cancer cells. Compound 13 showed the highest activity on both [...] Read more.
A series of epoxy- and/or 20-oxime pregnanes were synthesized from commercially available pregnenolone. Compounds 1, 3, 7, 8 and 11-13 were evaluated for cytotoxicity activity towards LNCaP (androgen-dependent) and PC-3 (androgenindependent) prostate cancer cells. Compound 13 showed the highest activity on both LNCaP (IC50 15.17 μM) and PC-3 (IC50 11.83 μM) cell lines. Compound 11 showed weak activity on LNCaP cells (IC50 71.85 μM) and 8 showed the weak activity on PC-3 cells (IC50 68.95 μM), respectively. The 5α-reductase II (5AR2) inhibitory effects of compounds 1-3, 5 and 7-13 were investigated in a convenient screening model, in which compounds 5, 8, 11 and 12 were observed to be potential inhibitors of 5α-reductase, in particular, the 4-azasteroid 11, that also inhibited cell proliferation of androgen-dependent cells and 8, that in addition inhibited PC-3 cells more potently than LNCaP cells. Full article
Open AccessArticle New Lipophilic Piceatannol Derivatives Exhibiting Antioxidant Activity Prepared by Aromatic Hydroxylation with 2-Iodoxybenzoic Acid (IBX)
Molecules 2009, 14(11), 4669-4681; doi:10.3390/molecules14114669
Received: 2 October 2009 / Revised: 17 November 2009 / Accepted: 17 November 2009 / Published: 17 November 2009
Cited by 10 | PDF Full-text (384 KB)
Abstract
Piceatannol (E-3,5,3’,4’-tetrahydroxystilbene) is a phytoalexin synthesized in grapes in response to stress conditions. It exhibits strong antioxidant and antileukaemic activities due to the presence of the catechol moiety. To modify some physical properties like solubility, and miscibility in non-aqueous media [...] Read more.
Piceatannol (E-3,5,3’,4’-tetrahydroxystilbene) is a phytoalexin synthesized in grapes in response to stress conditions. It exhibits strong antioxidant and antileukaemic activities due to the presence of the catechol moiety. To modify some physical properties like solubility, and miscibility in non-aqueous media some new previously unreported piceatannol derivatives having lipophilic chains on the A-ring were prepared in good yields by a simple and efficient procedure. The key step was a chemo- and regioselective aromatic hydroxylation with 2-iodoxybenzoic acid (IBX). The new compounds showed antioxidant activity and seemed promising for possible applications as multifunctional emulsifiers in food, cosmetic and pharmaceutical fields. Full article
(This article belongs to the Special Issue Organic Iodine Chemistry)
Open AccessArticle Cellulose/Gold Nanocrystal Hybrids via an Ionic Liquid/Aqueous Precipitation Route
Molecules 2009, 14(11), 4682-4688; doi:10.3390/molecules14114682
Received: 9 October 2009 / Revised: 12 November 2009 / Accepted: 17 November 2009 / Published: 18 November 2009
Cited by 11 | PDF Full-text (764 KB)
Abstract
Injection of a mixture of HAuCl4 and cellulose dissolved in the ionic liquid (IL) 1-butyl-3-methylimidazolium chloride [Bmim]Cl into aqueous NaBH4 leads to colloidal gold nanoparticle/cellulose hybrid precipitates. This process is a model example for a very simple and generic approach towards [...] Read more.
Injection of a mixture of HAuCl4 and cellulose dissolved in the ionic liquid (IL) 1-butyl-3-methylimidazolium chloride [Bmim]Cl into aqueous NaBH4 leads to colloidal gold nanoparticle/cellulose hybrid precipitates. This process is a model example for a very simple and generic approach towards (noble) metal/cellulose hybrids, which could find applications in sensing, sterile filtration, or as biomaterials. Full article
(This article belongs to the Special Issue Ionic Liquids)
Open AccessArticle Chemosystematic Value of the Essential Oil Composition of Thuja species Cultivated in Poland—Antimicrobial Activity
Molecules 2009, 14(11), 4707-4715; doi:10.3390/molecules14114707
Received: 21 October 2009 / Revised: 5 November 2009 / Accepted: 9 November 2009 / Published: 19 November 2009
Cited by 21 | PDF Full-text (218 KB)
Abstract
In the framework of the correlation between chemotaxonomy and chemical analysis studies, the chemical composition of the essential oils of four varieties of Thuja species cultivated in Poland − T. occidentalis ‘globosa’, T. occidentalis ‘aurea’, T. plicata and T. plicata [...] Read more.
In the framework of the correlation between chemotaxonomy and chemical analysis studies, the chemical composition of the essential oils of four varieties of Thuja species cultivated in Poland − T. occidentalis ‘globosa’, T. occidentalis ‘aurea’, T. plicata and T. plicata ‘gracialis’ − were investigated by GC and GC-MS. Thirty-one compounds were identified from T. occidentalis ‘globosa’, representing 96.92% of the total oil; twenty-seven from T. occidentalis ‘aurea’ (94.34%); thirty-one from T. plicata (94.75%); and thirty compounds from T. plicata ‘gracialis’ (96.36%). The main constituents in all samples were the monoterpene ketones α- and β-thujone, fenchone and sabinene, as well as the diterpenes beyerene and rimuene.The chemosystematic value of the total ketone content of all samples (which varied from 54.30–69.18%) has been discussed and investigated. The constituents, beyerene and the mixture of α- and β-thujone, were isolated from the oils and tested against six Gram-positive and -negative bacteria and three pathogenic fungi. The oils of the two T. plicata species exhibited significant antimicrobial activity, while the mixture of α- and β-thujone showed very strong activity as well. Full article
(This article belongs to the Special Issue Molecular Diversity Feature Papers)
Open AccessArticle Njaoaminiums A, B, and C: Cyclic 3-Alkylpyridinium Salts from the Marine Sponge Reniera sp.
Molecules 2009, 14(11), 4716-4724; doi:10.3390/molecules14114716
Received: 9 October 2009 / Revised: 3 November 2009 / Accepted: 17 November 2009 / Published: 19 November 2009
Cited by 6 | PDF Full-text (239 KB)
Abstract
Three novel cyclic 3-alkylpyridinium salts, named njaoaminiums A, B, and C (1-3), were isolated from the marine sponge Reniera sp., collected off the coasts of Pemba Island, Tanzania. The structural determination of the compounds was based on 1D and 2D NMR [...] Read more.
Three novel cyclic 3-alkylpyridinium salts, named njaoaminiums A, B, and C (1-3), were isolated from the marine sponge Reniera sp., collected off the coasts of Pemba Island, Tanzania. The structural determination of the compounds was based on 1D and 2D NMR studies and mass spectral determinations. Njaoaminiums B (2) and C (3) are the first examples of cyclic 3-alkylpyridinium salts bearing a methyl substituent on the alkyl chains. These compounds are assumed to be biosynthetic precursors of the njaoamines, previously isolated from the same sponge. The absolute configurations of the methyls of 2 and 3 were assigned by comparison between experimental and TDDFT calculated circular dichroism spectra on the most stable conformer. Compound 2 showed weak cytotoxicity against the three human tumor cell lines MDA-MB-231, A549, and HT29. Full article
Open AccessArticle Chemical Composition and Phytotoxic Effects of Essential Oils of Salvia hierosolymitana Boiss. and Salvia multicaulis Vahl. var. simplicifolia Boiss. Growing Wild in Lebanon
Molecules 2009, 14(11), 4725-4736; doi:10.3390/molecules14114725
Received: 19 October 2009 / Revised: 14 November 2009 / Accepted: 18 November 2009 / Published: 19 November 2009
Cited by 24 | PDF Full-text (123 KB)
Abstract
The chemical composition of the essential oils of S. hierosolymitana Boiss. and S. multicaulis Vahl. var. simplicifolia Boiss. collected in Lebanon was studied by means of GC and GC-MS analysis. In all 115 compounds were identified: 82 for S hierosolymitana and 72 [...] Read more.
The chemical composition of the essential oils of S. hierosolymitana Boiss. and S. multicaulis Vahl. var. simplicifolia Boiss. collected in Lebanon was studied by means of GC and GC-MS analysis. In all 115 compounds were identified: 82 for S hierosolymitana and 72 for S. multicaulis var. simplicifolia. The presence of carbonylic compounds (17%) characterizes the oil from S. hierosolymitana,while S. multicaulis var. simplicifolia oil is rich of monoterpenes (34.5%) and sesquiterpenes (46.9%). The effects of the essential oils on germination and initial radical elongation of Raphanus sativus L. (radish) and Lepidium sativum L. (garden cress) were studied, indicating in a different activity against radical elongation of the species tested. Full article
Open AccessArticle Preparation of Superhydrophobic Polymeric Film on Aluminum Plates by Electrochemical Polymerization
Molecules 2009, 14(11), 4737-4746; doi:10.3390/molecules14114737
Received: 15 October 2009 / Revised: 16 November 2009 / Accepted: 19 November 2009 / Published: 19 November 2009
Cited by 23 | PDF Full-text (319 KB)
Abstract
6-(N-Allyl-1,1,2,2-tetrahydroperfluorododecyl)amino-1,3,5-triazine-2,4-dithiol monosodium (ATP) was used to prepare polymeric thin films on pure aluminum plates to achieve a superhydrophobic surface. The electrochemical polymerization process of ATP on aluminum plates in NaNO2 aqueous solution and the formation of poly(6-(N-allyl-1,1,2,2-tetrahydroperfluorododecyl)amino-1,3,5-triazine-2,4-dithiol) [...] Read more.
6-(N-Allyl-1,1,2,2-tetrahydroperfluorododecyl)amino-1,3,5-triazine-2,4-dithiol monosodium (ATP) was used to prepare polymeric thin films on pure aluminum plates to achieve a superhydrophobic surface. The electrochemical polymerization process of ATP on aluminum plates in NaNO2 aqueous solution and the formation of poly(6-(N-allyl-1,1,2,2-tetrahydroperfluorododecyl)amino-1,3,5-triazine-2,4-dithiol) (PATP) thin film were studied by means of optical ellipsometry and film weight. The chemical structure of the polymeric film is investigated using FT-IR spectra and X-ray photoelectron spectroscopy (XPS). Contact angle goniometry was applied to measure the contact angles with distilled water drops at ambient temperature. The experimental results indicate that the polymeric film formed on pure aluminum plates exhibits superhydrophobic properties with a distilled water contact angle of 153°. The electrochemical polymerization process is time-saving, inexpensive, environmentally friendly and fairly convenient to carry out. It is expected that this technique will advance the production of superhydrophobic materials with new applications on a large scale. Moreover, this kind of polymeric thin film can be used as a dielectric material due to its insulating features. Full article
Open AccessArticle Spectroscopic Analyses of the Biofuels-Critical Phytochemical Coniferyl Alcohol and Its Enzyme-Catalyzed Oxidation Products
Molecules 2009, 14(11), 4758-4778; doi:10.3390/molecules14114758
Received: 21 October 2006 / Revised: 16 November 2006 / Accepted: 19 November 2009 / Published: 23 November 2009
PDF Full-text (564 KB)
Abstract
Lignin composition (monolignol types of coniferyl, sinapyl or p-coumaryl alcohol) is causally related to biomass recalcitrance. We describe multiwavelength (220, 228, 240, 250, 260, 290, 295, 300, 310 or 320 nm) absorption spectroscopy of coniferyl alcohol and its laccase- or peroxidase-catalyzed [...] Read more.
Lignin composition (monolignol types of coniferyl, sinapyl or p-coumaryl alcohol) is causally related to biomass recalcitrance. We describe multiwavelength (220, 228, 240, 250, 260, 290, 295, 300, 310 or 320 nm) absorption spectroscopy of coniferyl alcohol and its laccase- or peroxidase-catalyzed products during real time kinetic, pseudokinetic and endpoint analyses, in optical turn on or turn off modes, under acidic or basic conditions. Reactions in microwell plates and 100 μL volumes demonstrated assay miniaturization and high throughput screening capabilities. Bathochromic and hypsochromic shifts along with hyperchromicity or hypochromicity accompanied enzymatic oxidations by laccase or peroxidase. The limits of detection and quantitation of coniferyl alcohol averaged 2.4 and 7.1 μM respectively, with linear trend lines over 3 to 4 orders of magnitude. Coniferyl alcohol oxidation was evident within 10 minutes or with 0.01 μg/mL laccase and 2 minutes or 0.001 μg/mL peroxidase. Detection limit improved to 1.0 μM coniferyl alcohol with Km of 978.7 ± 150.7 μM when examined at 260 nm following 30 minutes oxidation with 1.0 μg/mL laccase. Our assays utilized the intrinsic spectroscopic properties of coniferyl alcohol or its oxidation products for enabling detection, without requiring chemical synthesis or modification of the substrate or product(s). These studies facilitate lignin compositional analyses and augment pretreatment strategies for reducing biomass recalcitrance. Full article
(This article belongs to the Special Issue High-throughput Screening)
Open AccessArticle Silica Sulfuric Acid Promotes Aza-Michael Addition Reactions under Solvent-Free Condition as a Heterogeneous and Reusable Catalyst
Molecules 2009, 14(11), 4779-4789; doi:10.3390/molecules14114779
Received: 3 November 2009 / Revised: 19 November 2009 / Accepted: 23 November 2009 / Published: 23 November 2009
Cited by 23 | PDF Full-text (185 KB)
Abstract
A highly efficient, inexpensive, recyclable, convenient, and green protocol for chemoselective aza-Michael addition reactions of amines/thiols to α,β-unsaturated compounds using silica sulfuric acid (SSA or SiO2-SO3H) was developed. This method is simple, convenient and the [...] Read more.
A highly efficient, inexpensive, recyclable, convenient, and green protocol for chemoselective aza-Michael addition reactions of amines/thiols to α,β-unsaturated compounds using silica sulfuric acid (SSA or SiO2-SO3H) was developed. This method is simple, convenient and the title compounds are produced in good to excellent yields. Full article

Review

Jump to: Research, Other

Open AccessReview Forming Glasses from Se and Te
Molecules 2009, 14(11), 4337-4350; doi:10.3390/molecules14114337
Received: 27 July 2009 / Revised: 1 September 2009 / Accepted: 23 October 2009 / Published: 26 October 2009
Cited by 50 | PDF Full-text (440 KB)
Abstract
Despite being close neighbors on the Periodic Table, selenium and tellurium present a totally different abilities to form glasses. Se is a very good glass former, and gives rise to numerous glass compositions which are popular for their transparency in the infrared [...] Read more.
Despite being close neighbors on the Periodic Table, selenium and tellurium present a totally different abilities to form glasses. Se is a very good glass former, and gives rise to numerous glass compositions which are popular for their transparency in the infrared range and their stability against crystallization. These glasses can be shaped into sophisticated optical devices such as optical fibers, planar guides or lenses. Nevertheless, their transparencies are limited at about 12 μm (depending on the thickness of the optical systems) due to the relatively small mass of the Se element. On the other hand, tellurium is heavier and its use in substitution for Se permits to shift the IR cutoff beyond 20 μm. However, the semimetallic nature of Te limits its glass formation ability and this glass family is known to be unstable and consequently has found application as phase change material in the Digital Versatile Disk (DVD) technology. In this paper, after a review of selenide glasses and their applications, it will be shown how, in a recent past, it has been possible to stabilize tellurium glasses by introducing new elements like Ga or I in their compositions. Full article
(This article belongs to the Special Issue Selenium and Tellurium Chemistry)
Open AccessReview 13C-NMR Data of Three Important Diterpenes Isolated from Euphorbia Species
Molecules 2009, 14(11), 4454-4475; doi:10.3390/molecules14114454
Received: 21 October 2009 / Revised: 2 November 2009 / Accepted: 4 November 2009 / Published: 6 November 2009
Cited by 14 | PDF Full-text (381 KB)
Abstract
Euphorbia species are widely distributed plants, many of which are used in folk medicine. Over the past twenty years, they have received considerable phytochemical and biological attention. Their diterpenoid constituents, especially those with abietane, tigliane, ingenane skeletons, are thought to be the [...] Read more.
Euphorbia species are widely distributed plants, many of which are used in folk medicine. Over the past twenty years, they have received considerable phytochemical and biological attention. Their diterpenoid constituents, especially those with abietane, tigliane, ingenane skeletons, are thought to be the main toxicant and bioactive factors. In this work, the utility of 13C-NMR spectroscopy for the structural elucidation of these compounds is briefly discussed. Full article
Open AccessReview Bystander or No Bystander for Gene Directed Enzyme Prodrug Therapy
Molecules 2009, 14(11), 4517-4545; doi:10.3390/molecules14114517
Received: 10 October 2009 / Revised: 3 November 2009 / Accepted: 5 November 2009 / Published: 10 November 2009
Cited by 50 | PDF Full-text (390 KB)
Abstract
Gene directed enzyme prodrug therapy (GDEPT) of cancer aims to improve the selectivity of chemotherapy by gene transfer, thus enabling target cells to convert nontoxic prodrugs to cytotoxic drugs. A zone of cell kill around gene-modified cells due to transfer of toxic [...] Read more.
Gene directed enzyme prodrug therapy (GDEPT) of cancer aims to improve the selectivity of chemotherapy by gene transfer, thus enabling target cells to convert nontoxic prodrugs to cytotoxic drugs. A zone of cell kill around gene-modified cells due to transfer of toxic metabolites, known as the bystander effect, leads to tumour regression. Here we discuss the implications of either striving for a strong bystander effect to overcome poor gene transfer, or avoiding the bystander effect to reduce potential systemic effects, with the aid of three successful GDEPT systems. This review concentrates on bystander effects and drug development with regard to these enzyme prodrug combinations, namely herpes simplex virus thymidine kinase (HSV-TK) with ganciclovir (GCV), cytosine deaminase (CD) from bacteria or yeast with 5-fluorocytodine (5-FC), and bacterial nitroreductase (NfsB) with 5-(azaridin-1-yl)-2,4-dinitrobenzamide (CB1954), and their respective derivatives. Full article
(This article belongs to the Special Issue Prodrugs)
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Open AccessReview Simple Sequence Repeat Polymorphisms (SSRPs) for Evaluation of Molecular Diversity and Germplasm Classification of Minor Crops
Molecules 2009, 14(11), 4546-4569; doi:10.3390/molecules14114546
Received: 13 September 2009 / Revised: 5 November 2009 / Accepted: 10 November 2009 / Published: 10 November 2009
Cited by 54 | PDF Full-text (406 KB)
Abstract
Evaluation of the genetic diversity among populations is an essential prerequisite for the preservation of endangered species. Thousands of new accessions are introduced into germplasm institutes each year, thereby necessitating assessment of their molecular diversity before elimination of the redundant genotypes. Of [...] Read more.
Evaluation of the genetic diversity among populations is an essential prerequisite for the preservation of endangered species. Thousands of new accessions are introduced into germplasm institutes each year, thereby necessitating assessment of their molecular diversity before elimination of the redundant genotypes. Of the protocols that facilitate the assessment of molecular diversity, SSRPs (simple sequence repeat polymorphisms) or microsatellite variation is the preferred system since it detects a large number of DNA polymorphisms with relatively simple technical complexity. The paucity of information on DNA sequences has limited their widespread utilization in the assessment of genetic diversity of minor or neglected crop species. However, recent advancements in DNA sequencing and PCR technologies in conjunction with sophisticated computer software have facilitated the development of SSRP markers in minor crops. This review examines the development and molecular nature of SSR markers, and their utilization in many aspects of plant genetics and ecology. Full article
(This article belongs to the Special Issue Molecular Diversity Feature Papers)
Open AccessReview The Trypanocidal Activity of Naphthoquinones: A Review
Molecules 2009, 14(11), 4570-4590; doi:10.3390/molecules14114570
Received: 1 October 2009 / Revised: 29 October 2009 / Accepted: 31 October 2009 / Published: 10 November 2009
Cited by 87 | PDF Full-text (599 KB)
Abstract
Naphthoquinones are compounds present in several families of higher plants. Their molecular structures confer redox properties, and they are involved in multiple biological oxidative processes. In folk medicine, especially among Indian populations, plants containing naphthoquinones have been employed for the treatment of [...] Read more.
Naphthoquinones are compounds present in several families of higher plants. Their molecular structures confer redox properties, and they are involved in multiple biological oxidative processes. In folk medicine, especially among Indian populations, plants containing naphthoquinones have been employed for the treatment of various diseases. The biological redox cycle of quinones can be initiated by one electron reduction leading to the formation of semiquinones, unstable intermediates that react rapidly with molecular oxygen, generating free radicals. Alternatively, the reduction by two electrons, mediated by DT-diphorase, leads to the formation of hydroquinone. Lapachol, α-lapachone and β-lapachone, which are isolated from the heartwood of trees of the Bignoniaceae family, are examples of bioactive naphthoquinones. In this review, we will discuss studies investigating the activity of these natural products and their derivatives in the context of the search for alternative drugs for Chagas disease, caused by Trypanosoma cruzi, a neglected illness that is endemic in Latin America. Full article
(This article belongs to the Special Issue Neglected Diseases: Medicinal Chemistry and Natural Product Chemistry)
Open AccessReview Steroidal Triterpenes: Design of Substrate-Based Inhibitors of Ergosterol and Sitosterol Synthesis
Molecules 2009, 14(11), 4690-4706; doi:10.3390/molecules14114690
Received: 22 September 2009 / Revised: 5 November 2009 / Accepted: 10 November 2009 / Published: 18 November 2009
Cited by 9 | PDF Full-text (1064 KB)
Abstract
This article reviews the design and study, in our own laboratory and others, of new steroidal triterpenes with a modified lanosterol or cycloartenol frame. These compounds, along with a number of known analogs with the cholestane skeleton, have been evaluated as reversible [...] Read more.
This article reviews the design and study, in our own laboratory and others, of new steroidal triterpenes with a modified lanosterol or cycloartenol frame. These compounds, along with a number of known analogs with the cholestane skeleton, have been evaluated as reversible or irreversible inhibitors of sterol C24-methyltransferase (SMT) from plants, fungi and protozoa. The SMT catalyzes the C24-methylation reaction involved with the introduction of the C24-methyl group of ergosterol and the C24-ethyl group of sitosterol, cholesterol surrogates that function as essential membrane inserts in many photosynthetic and non-photosynthetic eukaryotic organisms. Sterol side chains constructed with a nitrogen, sulfur, bromine or fluorine atom, altered to possess a methylene cyclopropane group, or elongated to include terminal double or triple bonds are shown to exhibit different in vitro activities toward the SMT which are mirrored in the inhibition potencies detected in the growth response of treated cultured human and plant cells or microbes. Several of the substrate-based analogs surveyed here appear to be taxaspecific compounds acting as mechanism-based inactivators of the SMT, a crucial enzyme not synthesized by animals. Possible mechanisms for the inactivation process and generation of novel products catalyzed by the variant SMTs are discussed. Full article
(This article belongs to the Special Issue Triterpenes and Triterpenoids)
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Open AccessReview Kinetic Resolution: A Powerful Tool for the Synthesis of Planar-Chiral Ferrocenes
Molecules 2009, 14(11), 4747-4757; doi:10.3390/molecules14114747
Received: 27 October 2009 / Revised: 16 November 2009 / Accepted: 19 November 2009 / Published: 20 November 2009
Cited by 21 | PDF Full-text (403 KB)
Abstract
Since the serendipitous discovery of ferrocene by Pauson and Kealy in 1951, it has become one of the most important structures in Organic Chemistry. Lately, kinetic resolution has emerged as a useful tool for the synthesis of planar chiral ferrocenes. This review [...] Read more.
Since the serendipitous discovery of ferrocene by Pauson and Kealy in 1951, it has become one of the most important structures in Organic Chemistry. Lately, kinetic resolution has emerged as a useful tool for the synthesis of planar chiral ferrocenes. This review aims to cover and discuss the development of this topic. Full article
(This article belongs to the Special Issue Ferrocenes)
Open AccessReview Synthetic Approaches and Biological Activities of 4-Hydroxycoumarin Derivatives
Molecules 2009, 14(11), 4790-4803; doi:10.3390/molecules14114790
Received: 19 October 2009 / Revised: 16 November 2009 / Accepted: 18 November 2009 / Published: 23 November 2009
Cited by 40 | PDF Full-text (273 KB)
Abstract The main purpose of this review is to summarize recent chemical syntheses and structural modifications of 4-hydroxycoumarin and its derivatives, of interest due to their characteristic conjugated molecular architecture and biological activities. Full article

Other

Jump to: Research, Review

Open AccessCorrection Omran, O.-A. The Reaction of Diethyl Bromomalonate with p-tert-butylthiacalix[4]arene: An Approach to Asymmetrical Derivatives Molecules 2009, 14, 1755-1761
Molecules 2009, 14(11), 4689; doi:10.3390/molecules14114689
Received: 17 November 2009 / Published: 19 November 2009
PDF Full-text (58 KB)
Abstract We found following errors in our paper published in Molecules recently [1]. [...] Full article

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