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Molecules, Volume 15, Issue 12 (December 2010), Pages 8534-9495

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Open AccessArticle Efficient Lewis Acid Ionic Liquid-Catalyzed Synthesis of the Key Intermediate of Coenzyme Q10 under Microwave Irradiation
Molecules 2010, 15(12), 9486-9495; https://doi.org/10.3390/molecules15129486
Received: 15 November 2010 / Revised: 13 December 2010 / Accepted: 20 December 2010 / Published: 22 December 2010
Cited by 13 | Viewed by 8285 | PDF Full-text (236 KB)
Abstract
An efficient synthesis of a valuable intermediate of coenzyme Q10 by microwave-assisted Lewis acidic ionic liquid (IL)-catalyzed Friedel-Crafts alkylation is reported. The acidity of six [Etpy]BF4-based ionic liquids was characterized by means of the FT-IR technique using acetonitrile as a
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An efficient synthesis of a valuable intermediate of coenzyme Q10 by microwave-assisted Lewis acidic ionic liquid (IL)-catalyzed Friedel-Crafts alkylation is reported. The acidity of six [Etpy]BF4-based ionic liquids was characterized by means of the FT-IR technique using acetonitrile as a molecular probe. The catalytic activities of these ionic liquids were correlated with their Lewis acidity. With increasing Lewis acid strength of the ionic liquids, their catalytic activity in the Friedel-Crafts reaction increased, except for [Etpy]BF4-AlCl3. The effects of the reaction system, the molar fraction of Lewis acid in the Lewis acid ILs and heating techniques were also investigated. Among the six Lewis acid ionic liquids tested [Etpy]BF4-ZnCl2 showed the best catalytic activity, with a yield of 89% after a very short reaction time (150 seconds). This procedure has the advantages of higher efficiency, better reusability of ILs, energy conservation and eco-friendliness. The method has practical value for preparation of CoQ10 on an industrial scale. Full article
Open AccessArticle A General Synthetic Procedure for 2-chloromethyl-4(3H)-quinazolinone Derivatives and Their Utilization in the Preparation of Novel Anticancer Agents with 4-Anilinoquinazoline Scaffolds
Molecules 2010, 15(12), 9473-9485; https://doi.org/10.3390/molecules15129473
Received: 27 October 2010 / Revised: 9 December 2010 / Accepted: 13 December 2010 / Published: 22 December 2010
Cited by 6 | Viewed by 7036 | PDF Full-text (507 KB)
Abstract
In our ongoing research on novel anticancer agents with 4-anilinoquinazoline scaffolds, a series of novel 2-chloromethyl-4(3H)-quinazolinones were needed as key intermediates. An improved one-step synthesis of 2-chloromethyl-4(3H)-quinazolinones utilizing o-anthranilic acids as starting materials was described. Based on it,
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In our ongoing research on novel anticancer agents with 4-anilinoquinazoline scaffolds, a series of novel 2-chloromethyl-4(3H)-quinazolinones were needed as key intermediates. An improved one-step synthesis of 2-chloromethyl-4(3H)-quinazolinones utilizing o-anthranilic acids as starting materials was described. Based on it, 2-hydroxy-methyl-4(3H)-quinazolinones were conveniently prepared in one pot. Moreover, two novel 4-anilinoquinazoline derivatives substituted with chloromethyl groups at the 2-position were synthesized and showed promising anticancer activity in vitro. Full article
Open AccessArticle Aristolactams and Alkamides of Aristolochia gigantea
Molecules 2010, 15(12), 9462-9472; https://doi.org/10.3390/molecules15129462
Received: 24 November 2010 / Revised: 16 December 2010 / Accepted: 17 December 2010 / Published: 21 December 2010
Cited by 23 | Viewed by 7042 | PDF Full-text (159 KB)
Abstract
A new aristolactam, aristolactam 9-O-β-D-glucopyranosyl-(1→2)-β-D-glucoside, and two alkamides, N-cis- and N-trans-p-coumaroyl-3-O-methyldopamine, were isolated from stems of Aristolochia gigantea, together with the known compounds allantoin, E-nerolidol, β-sitosterol, (+)-kobusin, (+)-eudesmin, trans-N-feruloyltyramine, trans-
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A new aristolactam, aristolactam 9-O-β-D-glucopyranosyl-(1→2)-β-D-glucoside, and two alkamides, N-cis- and N-trans-p-coumaroyl-3-O-methyldopamine, were isolated from stems of Aristolochia gigantea, together with the known compounds allantoin, E-nerolidol, β-sitosterol, (+)-kobusin, (+)-eudesmin, trans-N-feruloyltyramine, trans-N-coumaroyltyramine, trans-N-feruloyl-3-O-methyldopamine, aristolactam Ia-N-β-D-glucoside, aristolactam Ia 8-β-D-glucoside, aristolactam IIIa, and magnoflorine. Their structures were determined by spectroscopic analyses. Full article
(This article belongs to the Section Natural Products Chemistry)
Open AccessArticle Seasonal Variation in Total Phenolic and Flavonoid Contents and DPPH Scavenging Activity of Bellis perennis L. Flowers
Molecules 2010, 15(12), 9450-9461; https://doi.org/10.3390/molecules15129450
Received: 13 October 2010 / Revised: 14 December 2010 / Accepted: 20 December 2010 / Published: 21 December 2010
Cited by 41 | Viewed by 7337 | PDF Full-text (180 KB)
Abstract
Variations in total phenolic and flavonoid contents as well as antioxidant activity of Bellis perennis (common daisy) flowers were investigated. The flowers were collected monthly (from March to October, i.e., during the usual flowering season of the plant) at three localities in
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Variations in total phenolic and flavonoid contents as well as antioxidant activity of Bellis perennis (common daisy) flowers were investigated. The flowers were collected monthly (from March to October, i.e., during the usual flowering season of the plant) at three localities in three different years. Total flavonoids were determined spectrophotometrically by two methods: by formation of a complex with aluminium chloride after acidic hydrolysis of flower extracts (method 1) and by reaction with boric and oxalic acids in extracts without their modification (method 2). Total phenolics were determined spectrophotometrically using the Folin-Ciocalteu reagent. The antioxidant activity was determined spectrophotometrically by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The contents of flavonoids varied from 0.31 to 0.44 mg quercetin equivalent/100 mg dry weight (method 1) and from 1.37 to 2.20 mg pigenin-7-glucoside equivalent/100 mg dry weight (method 2). Total phenolics ranged from 2.81 to 3.57 mg gallic acid equivalent/100 mg dry weight. The antioxidant activity expressed as IC50 values varied from 66.03 to 89.27 µg/mL; it is about 50, 30, 20, and 10 times lower as compared with quercetin, ascorbic acid, Trolox®, and butylhydroxytoluene, respectively, and about five times higher in comparison with apigenin-7-glucoside. There is a significant correlation between antioxidant activity and total phenolics. No correlation between total flavonoid contents and antioxidant activity was observed. Contents of phenolics and flavonoids as well as antioxidant activity of daisy flowers vary to a relatively small extent during the year and are not dependant on the time of collection. Thus, the flowers possess comparable quality as to these characteristics over the whole flowering season of Bellis perennis. Effects of environmental factors on the amounts of secondary metabolites in plants are also discussed. Full article
(This article belongs to the Special Issue Phenolics and Polyphenolics)
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Open AccessReview Application of Cycloaddition Reactions to the Syntheses of Novel Boron Compounds
Molecules 2010, 15(12), 9437-9449; https://doi.org/10.3390/molecules15129437
Received: 11 October 2010 / Revised: 16 December 2010 / Accepted: 20 December 2010 / Published: 21 December 2010
Cited by 3 | Viewed by 6871 | PDF Full-text (708 KB)
Abstract
This review covers the application of cycloaddition reactions in forming the boron-containing compounds such as symmetric star-shaped boron-enriched dendritic molecules, nano-structured boron materials and aromatic boronic esters. The resulting boron compounds are potentially important reagents for both materials science and medical applications such
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This review covers the application of cycloaddition reactions in forming the boron-containing compounds such as symmetric star-shaped boron-enriched dendritic molecules, nano-structured boron materials and aromatic boronic esters. The resulting boron compounds are potentially important reagents for both materials science and medical applications such as in boron neutron capture therapy (BNCT) in cancer treatment and as drug delivery agents and synthetic intermediates for carbon-carbon cross-coupling reactions. In addition, the use of boron cage compounds in a number of cycloaddition reactions to synthesize unique aromatic species will be reviewed briefly. Full article
(This article belongs to the Special Issue Cycloaddition Reactions in Organic Synthesis)
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Open AccessArticle Synthesis and Antitumor Activity of 3-Methyl-4-oxo-3,4-dihydroimidazo [5,1-d][1,2,3,5]tetrazine-8-carboxylates and -carboxamides
Molecules 2010, 15(12), 9427-9436; https://doi.org/10.3390/molecules15129427
Received: 4 November 2010 / Revised: 10 December 2010 / Accepted: 14 December 2010 / Published: 20 December 2010
Cited by 2 | Viewed by 5782 | PDF Full-text (174 KB)
Abstract
Seventeen novel 3-methyl-4-oxo-3,4-dihydroimidazo[5,1-d][1,2,3,5]tetrazine-8-carboxylate and -carboxamide derivatives were synthesized and evaluated for their growth inhibition in seven human solid tumor and a human leukemia HL-60 cell lines. Compound IVa showed more activity than the other compounds and the positive control temozolomide. In
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Seventeen novel 3-methyl-4-oxo-3,4-dihydroimidazo[5,1-d][1,2,3,5]tetrazine-8-carboxylate and -carboxamide derivatives were synthesized and evaluated for their growth inhibition in seven human solid tumor and a human leukemia HL-60 cell lines. Compound IVa showed more activity than the other compounds and the positive control temozolomide. In the presence of 40 mg/mL of IVa, the survival rate of all tested tumor cells was less than 10%. Esters displayed more potent antitumour activity than amides and temozolomide against HL-60 cells. These compounds also exhibited considerably enhanced water-solubility. Full article
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Open AccessArticle Facile and Convenient Synthesis of New Thieno[2,3-b]-Thiophene Derivatives
Molecules 2010, 15(12), 9418-9426; https://doi.org/10.3390/molecules15129418
Received: 12 October 2010 / Revised: 15 December 2010 / Accepted: 16 December 2010 / Published: 20 December 2010
Cited by 23 | Viewed by 6153 | PDF Full-text (114 KB)
Abstract
A facile and convenient synthesis of bis(2-(1H-benzo[d]imidazol-2(3H)-ylidene)-3-oxopropanenitrile), bis((3-amino-5-(methylthio)-1H-pyrazol-4-yl)methanone) and bis(2-thioxo-1,2-dihydropyrimidine-5-carbonitrile) derivatives incorporating a thieno- [2,3-b]thiophene moiety via versatile, readily accessible diethyl 3,4-dimethylthieno-[2,3-b]thiophene-2,5-dicarboxylate (1) is described. Full article
Open AccessArticle Synthesis of 2-(4,6-Dimethoxy-1,3,5-triazin-2-yloxyimino) Derivatives: Application in Solution Peptide Synthesis
Molecules 2010, 15(12), 9403-9417; https://doi.org/10.3390/molecules15129403
Received: 29 November 2010 / Revised: 14 December 2010 / Accepted: 15 December 2010 / Published: 20 December 2010
Cited by 6 | Viewed by 6295 | PDF Full-text (158 KB)
Abstract
A new class of 1,3,5-triazinyloxyimino derivatives were prepared, characterized and tested for reactivity in solution peptide synthesis. The new triazinyloxyimino derivatives failed to activate the carboxyl group during formation of peptide bonds, but gave the corresponding N-triazinyl amino acid derivatives as a
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A new class of 1,3,5-triazinyloxyimino derivatives were prepared, characterized and tested for reactivity in solution peptide synthesis. The new triazinyloxyimino derivatives failed to activate the carboxyl group during formation of peptide bonds, but gave the corresponding N-triazinyl amino acid derivatives as a major product. The oxyma (ethyl 2-cyano-2-(hydroxyimino)acetate) uronium salt was superior to other uronium salts in terms of racemization, while 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT, 9) gave the best results. Full article
Open AccessArticle Insecticidal Activity of Essential Oil of Carum Carvi Fruits from China and Its Main Components against Two Grain Storage Insects
Molecules 2010, 15(12), 9391-9402; https://doi.org/10.3390/molecules15129391
Received: 23 November 2010 / Revised: 10 December 2010 / Accepted: 17 December 2010 / Published: 20 December 2010
Cited by 54 | Viewed by 9374 | PDF Full-text (161 KB)
Abstract
During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Carum carvi fruits was found to possess strong contact toxicity against Sitophilus zeamais and Tribolium castaneum adults, with LD50 values of 3.07 and 3.29 mg/adult,
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During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Carum carvi fruits was found to possess strong contact toxicity against Sitophilus zeamais and Tribolium castaneum adults, with LD50 values of 3.07 and 3.29 mg/adult, respectively, and also showed strong fumigant toxicity against the two grain storage insects with LC50 values of 3.37 and 2.53 mg/L, respectively. The essential oil obtained by hydrodistillation was investigated by GC and GC-MS. The main components of the essential oil were identified to be (R)-carvone (37.98%) and D-limonene (26.55%) followed by α-pinene (5.21), cis-carveol (5.01%) and b-myrcene (4.67%). (R)-Carvone and D-limonene were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. (R)-Carvone and D-limonene showed strong contact toxicity against S. zeamais (LD50 = 2.79 and 29.86 mg/adult) and T. castaneum (LD50 = 2.64 and 20.14 mg/adult). (R)-Carvone and D-limonene also possessed strong fumigant toxicity against S. zeamais (LC50 = 2.76 and 48.18 mg/L) and T. castaneum adults (LC50 = 1.96 and 19.10 mg/L). Full article
Open AccessCommunication Frameshifting in the P6 cDNA Phage Display System
Molecules 2010, 15(12), 9380-9390; https://doi.org/10.3390/molecules15129380
Received: 9 November 2010 / Revised: 3 December 2010 / Accepted: 16 December 2010 / Published: 20 December 2010
Cited by 4 | Viewed by 7383 | PDF Full-text (427 KB)
Abstract
Phage display is a powerful technique that enables easy identification of targets for any type of ligand. Targets are displayed at the phage surface as a fusion protein to one of the phage coat proteins. By means of a repeated process of affinity
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Phage display is a powerful technique that enables easy identification of targets for any type of ligand. Targets are displayed at the phage surface as a fusion protein to one of the phage coat proteins. By means of a repeated process of affinity selection on a ligand, specific enrichment of displayed targets will occur. In our studies using C-terminal display of cDNA fragments to phage coat protein p6, we noticed the occasional enrichment of targets that do not contain an open reading frame. This event has previously been described in other phage display studies using N-terminal display of targets to phage coat proteins and was due to uncommon translational events like frameshifting. The aim of this study was to examine if C-terminal display of targets to p6 is also subjected to frameshifting. To this end, an enriched target not containing an open reading frame was selected and an E-tag was coupled at the C-terminus in order to measure target display at the surface of the phage. The tagged construct was subsequently expressed in 3 different reading frames and display of both target and E-tag measured to detect the occurrence of frameshifting. As a result, we were able to demonstrate display of the target both in the 0 and in the +1 reading frame indicating that frameshifting can also take place when C-terminal fusion to minor coat protein p6 is applied. Full article
(This article belongs to the Special Issue Phage Display of Combinatorial Libraries)
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Open AccessArticle Molecular Modeling Studies on 11H-Dibenz[b,e]azepine and Dibenz[b,f][1,4]oxazepine Derivatives as Potent Agonists of the Human TRPA1 Receptor
Molecules 2010, 15(12), 9364-9379; https://doi.org/10.3390/molecules15129364
Received: 22 November 2010 / Revised: 8 December 2010 / Accepted: 15 December 2010 / Published: 17 December 2010
Cited by 7 | Viewed by 5223 | PDF Full-text (271 KB)
Abstract
A computational strategy based on comparative molecular fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) was performed on a series of the 11H-dibenz[b,e]azepine and dibenz[b,f][1,4]oxazepine derivatives as potent agonists of the
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A computational strategy based on comparative molecular fields analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) was performed on a series of the 11H-dibenz[b,e]azepine and dibenz[b,f][1,4]oxazepine derivatives as potent agonists of the human TRPA1 receptor. The CoMFA and CoMSIA models resulting from a 21 molecule training set gave r2cv values of 0.631 and 0.542 and r2 values of 0.986 and 0.981, respectively. The statistically significant models were validated by a test set of five compounds with predictive r2pred. values of 0.967 and 0.981 for CoMFA and CoMSIA, respectively. A systemic external validation was also performed on the established models. The information obtained from 3D counter maps could facilitate the design of more potent human TRPA1 receptor agonists. Full article
Open AccessArticle Evaluation of the Bioactivity of Novel Spiroisoxazoline TypeCompounds against Normal and Cancer Cell Lines
Molecules 2010, 15(12), 9340-9353; https://doi.org/10.3390/molecules15129340
Received: 5 October 2010 / Revised: 3 November 2010 / Accepted: 2 December 2010 / Published: 17 December 2010
Cited by 15 | Viewed by 5106 | PDF Full-text (163 KB)
Abstract
The aim of this study was to investigate the in vitro cellular activity of novel spiroisoxazoline type compounds against normal and cancer cell lines from lung tissue (Hs888Lu), neuron-phenotypic cells (SH-SY5Y), neuroblastoma (SH-SY5Y), human histiocytic lymphoma (U937), lung cancer (A549), and leukaemia (HL-60).
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The aim of this study was to investigate the in vitro cellular activity of novel spiroisoxazoline type compounds against normal and cancer cell lines from lung tissue (Hs888Lu), neuron-phenotypic cells (SH-SY5Y), neuroblastoma (SH-SY5Y), human histiocytic lymphoma (U937), lung cancer (A549), and leukaemia (HL-60). Our bioassay program revealed that the spiroisoxazoline type compounds show cytotoxicity only in lymphoma cell lines, which is in contrast with the pyrrolidine precursor of these spiroisoxazoline compounds, where significant cytotoxicity is seen in all normal and cancer cell lines. These data suggest a tumour-specific mechanism of action. In addition these data also show that spiroisoxazoline compounds are non-toxic in the human neuronphenotypic neuroblastoma SH-SY5Y cell line, and furthermore that they might protect cells from neurodegenerative disease. Full article
(This article belongs to the collection Bioactive Compounds)
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Open AccessArticle The Influence of Mixed Activators on Ethylene Polymerization and Ethylene/1-Hexene Copolymerization with Silica-Supported Ziegler-Natta Catalyst
Molecules 2010, 15(12), 9323-9339; https://doi.org/10.3390/molecules15129323
Received: 15 November 2010 / Revised: 10 December 2010 / Accepted: 14 December 2010 / Published: 16 December 2010
Cited by 11 | Viewed by 7121 | PDF Full-text (1017 KB)
Abstract
This article reveals the effects of mixed activators on ethylene polymerization and ethylene/1-hexene copolymerization over MgCl2/SiO2-supported Ziegler-Natta (ZN) catalysts. First, the conventional ZN catalyst was prepared with SiO2 addition. Then, the catalyst was tested for ethylene polymerization and
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This article reveals the effects of mixed activators on ethylene polymerization and ethylene/1-hexene copolymerization over MgCl2/SiO2-supported Ziegler-Natta (ZN) catalysts. First, the conventional ZN catalyst was prepared with SiO2 addition. Then, the catalyst was tested for ethylene polymerization and ethylene/1-hexene (E/H) co-polymerization using different activators. Triethylaluminum (TEA), tri-n-hexyl aluminum (TnHA) and diethyl aluminum chloride (DEAC), TEA+DEAC, TEA+TnHA, TnHA+ DEAC, TEA+DEAC+TnHA mixtures, were used as activators in this study. It was found that in the case of ethylene polymerization with a sole activator, TnHA exhibited the highest activity among other activators due to increased size of the alkyl group. Further investigation was focused on the use of mixed activators. The activity can be enhanced by a factor of three when the mixed activators were employed and the activity of ethylene polymerization apparently increased in the order of TEA+ DEAC+TnHA > TEA+DEAC > TEA+TnHA. Both the copolymerization activity and crystallinity of the synthesized copolymers were strongly changed when the activators were changed from TEA to TEA+DEAC+TnHA mixtures or pure TnHA and pure DEAC. As for ethylene/1-hexene copolymerization the activity apparently increased in the order of TEA+DEAC+TnHA > TEA+TnHA > TEA+DEAC > TnHA+DEAC > TEA > TnHA > DEAC. Considering the properties of the copolymer obtained with the mixed TEA+DEAC+TnHA, its crystallinity decreased due to the presence of TnHA in the mixed activator. The activators thus exerted a strong influence on copolymer structure. An increased molecular weight distribution (MWD) was observed, without significant change in polymer morphology. Full article
Open AccessArticle Antioxidant Activity of Lignin Phenolic Compounds Extracted from Kraft and Sulphite Black Liquors
Molecules 2010, 15(12), 9308-9322; https://doi.org/10.3390/molecules15129308
Received: 19 October 2010 / Revised: 13 December 2010 / Accepted: 14 December 2010 / Published: 16 December 2010
Cited by 56 | Viewed by 6502 | PDF Full-text (276 KB)
Abstract
The antioxidant activity of the phenolic compounds present in industrial black liquors obtained from the two cooking processes (kraft and sulphite) used in Portugal to produce Eucalyptus globulus pulp was evaluated. The black liquors treated at several pH values were extracted with ethyl
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The antioxidant activity of the phenolic compounds present in industrial black liquors obtained from the two cooking processes (kraft and sulphite) used in Portugal to produce Eucalyptus globulus pulp was evaluated. The black liquors treated at several pH values were extracted with ethyl acetate. Phenolic fractions were further separated by liquid chromatography of the crude extracts of kraft liquor at pH = 6 and sulphite liquor at the original pH. Total phenolic content was determined in terms of gallic acid equivalents (Folin-Ciocalteu colorimetric method), and the antioxidant activity in the crude extracts at several pH values and in the separated fractions was measured using the DPPH test for radical scavenging capacity. The total phenolic content of crude extracts and separated fractions ranged from 92.7 to 181.6 and from 91.6 to 1,099.6 mg GAE/g, respectively, while the antioxidant activity index (AAI) ranged from 2.20 to 3.41 and from 2.21 to 11.47 respectively, showing very strong antioxidant activity in all studied cases. The fractions separated by column chromatography were submitted to mass spectrometry analysis and the results were compared to others in the literature of natural products, mainly from Eucalyptus, and the characteristic bands of functional groups were identified by 1H-NMR and FTIR. These methods allowed the identification of 17 phenolic compounds. Full article
(This article belongs to the Special Issue Phenolics and Polyphenolics)
Open AccessArticle A Novel Benzo[f][1,7]Naphthyridine Produced by Streptomyces Albogriseolus from Mangrove Sediments
Molecules 2010, 15(12), 9298-9307; https://doi.org/10.3390/molecules15129298
Received: 24 October 2010 / Revised: 30 November 2010 / Accepted: 7 December 2010 / Published: 15 December 2010
Cited by 17 | Viewed by 6450 | PDF Full-text (244 KB)
Abstract
Mangrove Streptomyces represent a rich source of novel bioactive compounds in medicinal research. A novel alkaloid, named 1-N-methyl-3-methylamino-[N-butanoic acid-3¢-(9¢-methyl-8¢-propen-7¢-one)-amide]-benzo[f][1,7]naphthyridine-2-one (1) was isolated from Streptomyces albogriseolus originating from mangrove sediments. The structure of compound 1 was elucidated by
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Mangrove Streptomyces represent a rich source of novel bioactive compounds in medicinal research. A novel alkaloid, named 1-N-methyl-3-methylamino-[N-butanoic acid-3¢-(9¢-methyl-8¢-propen-7¢-one)-amide]-benzo[f][1,7]naphthyridine-2-one (1) was isolated from Streptomyces albogriseolus originating from mangrove sediments. The structure of compound 1 was elucidated by extensive spectroscopic data analyses and verified by the 13C-NMR calculation at the B3LYP/6-311+G(2d,p) level of theory. Full article
(This article belongs to the Section Natural Products Chemistry)
Open AccessArticle Antimicrobial Activity of Sphingolipids Isolated from the Stems of Cucumber (Cucumis sativus L.)
Molecules 2010, 15(12), 9288-9297; https://doi.org/10.3390/molecules15129288
Received: 2 December 2010 / Revised: 10 December 2010 / Accepted: 13 December 2010 / Published: 15 December 2010
Cited by 22 | Viewed by 7473 | PDF Full-text (222 KB)
Abstract
Three antimicrobial sphingolipids were separated by bioassay-guided isolation from the chloroform fraction of the crude methanol extract of cucumber (Cucumis sativus L.) stems and identified as (2S,3S,4R,10E)-2-[(2'R)-2-hydroxytetra-cosanoylamino]-1,3,4-octadecanetriol-10-ene (1), 1-O-β-D-glucopyranosyl(2S,3S,4R,10E
[...] Read more.
Three antimicrobial sphingolipids were separated by bioassay-guided isolation from the chloroform fraction of the crude methanol extract of cucumber (Cucumis sativus L.) stems and identified as (2S,3S,4R,10E)-2-[(2'R)-2-hydroxytetra-cosanoylamino]-1,3,4-octadecanetriol-10-ene (1), 1-O-β-D-glucopyranosyl(2S,3S,4R,10E)-2-[(2'R)-2-hydroxy-tetracosanoylamino]-1,3,4-octadecanetriol-10-ene (2) and soya-cerebroside I (3) by their physicochemical properties and spectroscopic analysis. They were evaluated to show antifungal and antibacterial activity on test microorganisms including four fungal and three bacterial species. Among them, compound 1, a relatively low polarity aglycone, exhibited stronger antimicrobial activity than its corresponding glycoside 2. The results indicated that sphingolipids could be the main antimicrobial compounds in the crude methanol extract of cucumber stems. Full article
(This article belongs to the collection Bioactive Compounds)
Open AccessReview Antioxidant and Anti-Inflammatory Activities of Essential Oils: A Short Review
Molecules 2010, 15(12), 9252-9287; https://doi.org/10.3390/molecules15129252
Received: 2 December 2010 / Revised: 9 December 2010 / Accepted: 13 December 2010 / Published: 15 December 2010
Cited by 255 | Viewed by 18470 | PDF Full-text (311 KB)
Abstract
Essential oils are complex mixtures isolated from aromatic plants which may possess antioxidant and anti-inflammatory activities of interest in thye food and cosmetic industries as well as in the human health field. In this work, a review was done on the most recent
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Essential oils are complex mixtures isolated from aromatic plants which may possess antioxidant and anti-inflammatory activities of interest in thye food and cosmetic industries as well as in the human health field. In this work, a review was done on the most recent publications concerning their antioxidant and anti-inflammatory activities. At the same time a survey of the methods generally used for the evaluation of antioxidant activity and some of the mechanisms involved in the anti-inflammatory activities of essential oils are also reported. Full article
Open AccessReview [2+2+2] Cycloaddition Reactions of Macrocyclic Systems Catalyzed by Transition Metals. A Review
Molecules 2010, 15(12), 9230-9251; https://doi.org/10.3390/molecules15129230
Received: 24 November 2010 / Revised: 10 December 2010 / Accepted: 14 December 2010 / Published: 15 December 2010
Cited by 43 | Viewed by 9283 | PDF Full-text (224 KB)
Abstract
Polyalkyne and enediyne azamacrocycles are prepared from arenesulfonamides and various alkyne and alkene derivatives either under basic or neutral conditions. The new family of macrocyclic substrates is tested in the [2+2+2] cycloaddition reaction. Several catalysts are used for the cycloisomerization reaction, and their
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Polyalkyne and enediyne azamacrocycles are prepared from arenesulfonamides and various alkyne and alkene derivatives either under basic or neutral conditions. The new family of macrocyclic substrates is tested in the [2+2+2] cycloaddition reaction. Several catalysts are used for the cycloisomerization reaction, and their enantioinduction is evaluated as appropriate. The effect of the structural features of the macrocycles, namely the ring size, substituents in precise positions and the number and type of unsaturations, on the [2+2+2] cycloaddition reaction has also been studied. Full article
(This article belongs to the Special Issue Cycloaddition Reactions in Organic Synthesis)
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Open AccessArticle An Improved in Vivo Deuterium Labeling Method for Measuring the Biosynthetic Rate of Cytokinins
Molecules 2010, 15(12), 9214-9229; https://doi.org/10.3390/molecules15129214
Received: 10 October 2010 / Accepted: 14 December 2010 / Published: 15 December 2010
Cited by 3 | Viewed by 6118 | PDF Full-text (253 KB)
Abstract
An improved method for determining the relative biosynthetic rate of isoprenoid cytokinins has been developed. A set of 11 relevant isoprenoid cytokinins, including zeatin isomers, was separated by ultra performance liquid chromatography in less than 6 min. The iP-type cytokinins were observed to
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An improved method for determining the relative biosynthetic rate of isoprenoid cytokinins has been developed. A set of 11 relevant isoprenoid cytokinins, including zeatin isomers, was separated by ultra performance liquid chromatography in less than 6 min. The iP-type cytokinins were observed to give rise to a previously-unknown fragment at m/z 69; we suggest that the diagnostic (204-69) transition can be used to monitor the biosynthetic rate of isopentenyladenine. Furthermore, we found that by treating the cytokinin nucleotides with alkaline phosphatase prior to analysis, the sensitivity of the detection process could be increased. In addition, derivatization (propionylation) improved the ESI-MS response by increasing the analytes' hydrophobicity. Indeed, the ESI-MS response of propionylated isopentenyladenosine was about 34% higher than that of its underivatized counterpart. Moreover, the response of the derivatized zeatin ribosides was about 75% higher than that of underivatized zeatin ribosides. Finally, we created a web-based calculator (IZOTOP) that facilitates MS/MS data processing and offer it freely to the research community. Full article
(This article belongs to the Special Issue Phytochemicals with Signaling, Medicinal and Therapeutic Properties)
Open AccessArticle Alkaloids from Stems of Esenbeckia leiocarpa Engl. (Rutaceae) as Potential Treatment for Alzheimer Disease
Molecules 2010, 15(12), 9205-9213; https://doi.org/10.3390/molecules15129205
Received: 15 November 2010 / Revised: 2 December 2010 / Accepted: 6 December 2010 / Published: 13 December 2010
Cited by 33 | Viewed by 7746 | PDF Full-text (77 KB)
Abstract
Esenbeckia leiocarpa Engl. (Rutaceae), popularly known as guarantã, goiabeira, is a native tree from Brazil. Bioactivity-guided fractionation of the ethanol stems extract afforded the isolation of six alkaloids: leiokinine A, leptomerine, kokusaginine, skimmianine, maculine and flindersiamine. All isolated compounds were tested for
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Esenbeckia leiocarpa Engl. (Rutaceae), popularly known as guarantã, goiabeira, is a native tree from Brazil. Bioactivity-guided fractionation of the ethanol stems extract afforded the isolation of six alkaloids: leiokinine A, leptomerine, kokusaginine, skimmianine, maculine and flindersiamine. All isolated compounds were tested for acetyl cholinesterase inhibition, in vitro and displayed anticholinesterasic activity. The alkaloid leptomerine showed the highest activity (IC50 = 2.5 mM), similar to that of the reference compound galanthamine (IC50 = 1.7 mM). The results showed for the first time the presence of alkaloids leptomerine and skimmianine in E. leiocarpa (Engl.) with potent anticholinesterasic activity. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle An Efficient Synthesis of 1-Aryl-3-(indole-3-yl)-3-(2-aryl-1,2,3-triazol-4-yl)propan-1-one Catalyzed by a Brønsted Acid Ionic Liquid
Molecules 2010, 15(12), 9197-9204; https://doi.org/10.3390/molecules15129197
Received: 11 October 2010 / Revised: 3 December 2010 / Accepted: 7 December 2010 / Published: 10 December 2010
Cited by 4 | Viewed by 4718 | PDF Full-text (193 KB)
Abstract
An efficient synthesis of novel 1-aryl-3-(indole-3-yl)-3-(2-aryl-1,2,3-triazol-4-yl)propan-1-ones from indoles and 1-aryl-3-(2-aryl-1,2,3-triazol-4-yl)propan-1-one using a Brønsted acid ionic liquid [Sbmim][HSO4] as catalyst is described. Satisfactory results with excellent yields and short reaction time were obtained in the experiments. The catalyst could be recovered conveniently
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An efficient synthesis of novel 1-aryl-3-(indole-3-yl)-3-(2-aryl-1,2,3-triazol-4-yl)propan-1-ones from indoles and 1-aryl-3-(2-aryl-1,2,3-triazol-4-yl)propan-1-one using a Brønsted acid ionic liquid [Sbmim][HSO4] as catalyst is described. Satisfactory results with excellent yields and short reaction time were obtained in the experiments. The catalyst could be recovered conveniently and reused efficiently. Full article
Open AccessArticle Volatile Compounds of Young Wines from Cabernet Sauvignon, Cabernet Gernischet and Chardonnay Varieties Grown in the Loess Plateau Region of China
Molecules 2010, 15(12), 9184-9196; https://doi.org/10.3390/molecules15129184
Received: 6 October 2010 / Revised: 6 December 2010 / Accepted: 8 December 2010 / Published: 10 December 2010
Cited by 60 | Viewed by 4707 | PDF Full-text (221 KB)
Abstract
In order to elucidate the aroma components of wine produced in the Loess Plateau region of China, volatile compounds of young wines from Cabernet Sauvignon, Cabernet Gernischet and Chardonnay varieties grown in the new ecological region were investigated for the first time in
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In order to elucidate the aroma components of wine produced in the Loess Plateau region of China, volatile compounds of young wines from Cabernet Sauvignon, Cabernet Gernischet and Chardonnay varieties grown in the new ecological region were investigated for the first time in this research. Among the volatile compounds analyzed by HS-SPME with GC-MS, a total of 45, 44 and 42 volatile compounds were identified and quantified in Cabernet Sauvignon, Cabernet Gernischet and Chardonnay wines, respectively. In the volatiles detected, alcohols formed the most abundant group in the aroma compounds of the three wines, followed by esters and fatty acids. According to their odor active values (OAVs), 18 volatile compounds were always present in the three wines at concentrations higher than their threshold values, but ethyl octanoate, ethyl hexanoate, and isoamyl acetate were found to jointly contribute to 92.9%, 93.3%, and 98.7%, of the global aroma of Cabernet Sauvignon, Cabernet Gernischet and Chardonnay wines, respectively. These odorants are associated with “fruity’’ and ‘‘ripe fruit’’ odor descriptors. Full article
Open AccessArticle Synthesis and Biological Activity of trans-Tiliroside Derivatives as Potent Anti-Diabetic Agents
Molecules 2010, 15(12), 9174-9183; https://doi.org/10.3390/molecules15129174
Received: 29 October 2010 / Revised: 7 December 2010 / Accepted: 8 December 2010 / Published: 10 December 2010
Cited by 17 | Viewed by 6174 | PDF Full-text (181 KB)
Abstract
A set of novel trans-tiliroside derivatives were synthesized. The structures of the derivatives were identified by their IR, 1H-NMR, and MS spectra analysis. Their anti-diabetic activities were evaluated on the insulin resistant (IR) HepG2 cell model. As a result, compounds 7a
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A set of novel trans-tiliroside derivatives were synthesized. The structures of the derivatives were identified by their IR, 1H-NMR, and MS spectra analysis. Their anti-diabetic activities were evaluated on the insulin resistant (IR) HepG2 cell model. As a result, compounds 7a, 7c, 7h, and trans-tiliroside exhibited significant glucose consumption-enhancing effects in IR-HepG2 cells compared with the positive control (metformin). This research provides useful clues for further design and discovery of anti-diabetic agents. Full article
(This article belongs to the Special Issue Structure-Based Drug Design)
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Open AccessArticle Sonogashira Reaction of Aryl and Heteroaryl Halides with Terminal Alkynes Catalyzed by a Highly Efficient and Recyclable Nanosized MCM-41 Anchored Palladium Bipyridyl Complex
Molecules 2010, 15(12), 9157-9173; https://doi.org/10.3390/molecules15129157
Received: 11 November 2010 / Revised: 6 December 2010 / Accepted: 9 December 2010 / Published: 10 December 2010
Cited by 52 | Viewed by 7405 | PDF Full-text (171 KB)
Abstract
A heterogeneous catalyst, nanosized MCM-41-Pd, was used to catalyze the Sonogashira coupling of aryl and heteroaryl halides with terminal alkynes in the presence of CuI and triphenylphosphine. The coupling products were obtained in high yields using low Pd loadings to 0.01 mol%, and
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A heterogeneous catalyst, nanosized MCM-41-Pd, was used to catalyze the Sonogashira coupling of aryl and heteroaryl halides with terminal alkynes in the presence of CuI and triphenylphosphine. The coupling products were obtained in high yields using low Pd loadings to 0.01 mol%, and the nanosized MCM-41-Pd catalyst was recovered by centrifugation of the reaction solution and re-used in further runs without significant loss of reactivity. Full article
(This article belongs to the Special Issue Cross-Coupling Reactions in Organic Synthesis)
Open AccessArticle Antioxidant Activities of Total Phenols of Prunella vulgaris L. in Vitro and in Tumor-bearing Mice
Molecules 2010, 15(12), 9145-9156; https://doi.org/10.3390/molecules15129145
Received: 19 September 2010 / Revised: 22 November 2010 / Accepted: 8 December 2010 / Published: 10 December 2010
Cited by 25 | Viewed by 7330 | PDF Full-text (229 KB)
Abstract
Prunella vulgaris L. (PV, Labiatae) is known as a self-heal herb. The different extracts of dried spikes were studied for the best antioxidant active compounds. The 60% ethanol extract (P-60) showed strong antioxidant activity based on the results of 2,2’-azino-di(3-ethylbenzthiazoline-6-sulfonic acid (ABTS˙+), 2,2-diphenyl-1-picrylhydrazyl
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Prunella vulgaris L. (PV, Labiatae) is known as a self-heal herb. The different extracts of dried spikes were studied for the best antioxidant active compounds. The 60% ethanol extract (P-60) showed strong antioxidant activity based on the results of 2,2’-azino-di(3-ethylbenzthiazoline-6-sulfonic acid (ABTS˙+), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assay methods. High performance liquid chromatography (HPLC) and LC/MS analysis showed that the main active compounds in P-60 were phenols, such as caffeic acid, rosmarinic acid, rutin and quercetin. Total phenols were highly correlated with the antioxidant activity (R2 = 0.9988 in ABTS˙+; 0.6284 in DPPH and 0.9673 FRAP tests). P-60 could inhibit significantly the tumor growth in C57BL/6 mice. It can also been showed that increased superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) content in serum of tumor-bearing mice. These results suggested that P-60 extract had high antioxidant activity in vitro and in vivo and total phenols played an important role in antioxidant activity for inhibition of tumor growth. Full article
Open AccessArticle Unexplored Nucleophilic Ring Opening of Aziridines
Molecules 2010, 15(12), 9135-9144; https://doi.org/10.3390/molecules15129135
Received: 24 November 2010 / Revised: 1 December 2010 / Accepted: 6 December 2010 / Published: 10 December 2010
Cited by 2 | Viewed by 6111 | PDF Full-text (279 KB)
Abstract
The reactivity of dianions of carboxylic acids towards aziridines has been studied. Although, a similar reactivity to that of enolates from ketones, esters or amides has been observed, the method directly yields g-aminoacids in one step. The method is complementary of previous results
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The reactivity of dianions of carboxylic acids towards aziridines has been studied. Although, a similar reactivity to that of enolates from ketones, esters or amides has been observed, the method directly yields g-aminoacids in one step. The method is complementary of previous results of enenediolate reactivity with other electrophiles. A comparative study with the reactivity of this enediolates with epoxides is included. Full article
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Open AccessReview Experimental Models for Assaying Microvascular Endothelial Cell Pathophysiology in Stroke
Molecules 2010, 15(12), 9104-9134; https://doi.org/10.3390/molecules15129104
Received: 29 October 2010 / Revised: 29 November 2010 / Accepted: 8 December 2010 / Published: 10 December 2010
Cited by 16 | Viewed by 9236 | PDF Full-text (207 KB)
Abstract
It is important to understand the molecular mechanisms underlying neuron death following stroke in order to develop effective neuroprotective strategies. Since studies on human stroke are extremely limited due to the difficulty in collecting post-mortem tissue at different time points after the onset
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It is important to understand the molecular mechanisms underlying neuron death following stroke in order to develop effective neuroprotective strategies. Since studies on human stroke are extremely limited due to the difficulty in collecting post-mortem tissue at different time points after the onset of stroke, brain ischaemia research focuses on information derived from in-vitro models of neuronal death through ischaemic injury [1]. This review aims to provide an update on the different in-vitro stroke models with brain microvascular endothelial cells that are currently being used. These models provide a physiologically relevant tool to screen potential neuroprotective drugs in stroke and to study the molecular mechanisms involved in brain ischaemia. Full article
(This article belongs to the Special Issue Neuroprotective Strategies)
Open AccessArticle Structural Relationship and Binding Mechanisms of Five Flavonoids with Bovine Serum Albumin
Molecules 2010, 15(12), 9092-9103; https://doi.org/10.3390/molecules15129092
Received: 9 October 2010 / Revised: 1 December 2010 / Accepted: 6 December 2010 / Published: 9 December 2010
Cited by 72 | Viewed by 7969 | PDF Full-text (386 KB)
Abstract
Flavonoids are structurally diverse and the most ubiquitous groups of dietary polyphenols distributed in various fruits and vegetables. In this study, the interaction between five flavonoids, namely formononetin-7-O-β-D-glucoside, calycosin- 7-O-β-D-glucoside, calycosin, rutin, and quercetin, and bovine serum albumin (BSA)
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Flavonoids are structurally diverse and the most ubiquitous groups of dietary polyphenols distributed in various fruits and vegetables. In this study, the interaction between five flavonoids, namely formononetin-7-O-β-D-glucoside, calycosin- 7-O-β-D-glucoside, calycosin, rutin, and quercetin, and bovine serum albumin (BSA) was investigated by fluorescence and UV-vis absorbance spectroscopy. In the discussion, it was proved that the fluorescence quenching of BSA by flavonoids was a result of the formation of a flavonoid-BSA complex. Fluorescence quenching constants were determined using the Stern-Volmer and Lineweaver-Burk equations to provide a measure of the binding affinity between the flavonoids and BSA. The binding constants ranked in the order quercetin > rutin > calycosin > calycosin-7-O-β-D-glucoside ≈ formononetin-7-O-β-D-glucoside. The results of thermodynamic parameters ΔG, ΔH, and ΔS at different temperatures indicated that the hydrophobic interaction played a major role in flavonoid-BSA association. The distance r between BSA and acceptor flavonoids was also obtained according to Förster’s theory of non-radiative energy transfer. Full article
Open AccessReview Biosynthesis of Anthocyanins and Their Regulation in Colored Grapes
Molecules 2010, 15(12), 9057-9091; https://doi.org/10.3390/molecules15129057
Received: 19 October 2010 / Accepted: 7 December 2010 / Published: 9 December 2010
Cited by 203 | Viewed by 15819 | PDF Full-text (504 KB)
Abstract
Anthocyanins, synthesized via the flavonoid pathway, are a class of crucial phenolic compounds which are fundamentally responsible for the red color of grapes and wines. As the most important natural colorants in grapes and their products, anthocyanins are also widely studied for their
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Anthocyanins, synthesized via the flavonoid pathway, are a class of crucial phenolic compounds which are fundamentally responsible for the red color of grapes and wines. As the most important natural colorants in grapes and their products, anthocyanins are also widely studied for their numerous beneficial effects on human health. In recent years, the biosynthetic pathway of anthocyanins in grapes has been thoroughly investigated. Their intracellular transportation and accumulation have also been further clarified. Additionally, the genetic mechanism regulating their biosynthesis and the phytohormone influences on them are better understood. Furthermore, due to their importance in the quality of wine grapes, the effects of the environmental factors and viticulture practices on anthocyanin accumulation are being investigated increasingly. The present paper summarizes both the basic information and the most recent advances in the study of the anthocyanin biosynthesis in red grapes, emphasizing their gene structure, the transcriptional factors and the diverse exterior regulation factors. Full article
(This article belongs to the Special Issue Phenolics and Polyphenolics)
Open AccessArticle Synthesis and Antiviral Activity of 5‑(4‑Chlorophenyl)-1,3,4-Thiadiazole Sulfonamides
Molecules 2010, 15(12), 9046-9056; https://doi.org/10.3390/molecules15129046
Received: 23 August 2010 / Revised: 10 November 2010 / Accepted: 30 November 2010 / Published: 9 December 2010
Cited by 66 | Viewed by 6776 | PDF Full-text (227 KB)
Abstract
Starting from 4-chlorobenzoic acid, 10 new 5-(4-chlorophenyl)-N-substituted-N-1,3,4-thiadiazole-2-sulfonamide derivatives were synthesized in six-steps. Esterification of 4-chlorobenzoic acid with methanol and subsequent hydrazination, salt formation and cyclization afforded 5-(4-chlorophen-yl)-1,3,4-thiadiazole-2-thiol (5). Conversion of this intermediate into sulfonyl chloride 6,
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Starting from 4-chlorobenzoic acid, 10 new 5-(4-chlorophenyl)-N-substituted-N-1,3,4-thiadiazole-2-sulfonamide derivatives were synthesized in six-steps. Esterification of 4-chlorobenzoic acid with methanol and subsequent hydrazination, salt formation and cyclization afforded 5-(4-chlorophen-yl)-1,3,4-thiadiazole-2-thiol (5). Conversion of this intermediate into sulfonyl chloride 6, followed by nucleophilic attack of the amines gave the title sulfonamides 7a-7j whose structures were confirmed by NMR, IR and elemental analysis. The bioassay tests showed that compounds 7b and 7i possessed certain anti-tobacco mosaic virus activity. Full article
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