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Molecules, Volume 15, Issue 12 (December 2010) – 65 articles , Pages 8534-9495

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236 KiB  
Article
Efficient Lewis Acid Ionic Liquid-Catalyzed Synthesis of the Key Intermediate of Coenzyme Q10 under Microwave Irradiation
by Yue Chen, Yuangang Zu, Yujie Fu, Xuan Zhang, Ping Yu, Guoyong Sun and Thomas Efferth
Molecules 2010, 15(12), 9486-9495; https://doi.org/10.3390/molecules15129486 - 22 Dec 2010
Cited by 16 | Viewed by 11022
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 [...] Read more.
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
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507 KiB  
Article
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
by Hong-Ze Li, Hai-Yun He, Yuan-Yuan Han, Xin Gu, Lin He, Qing-Rong Qi, Ying-Lan Zhao and Li Yang
Molecules 2010, 15(12), 9473-9485; https://doi.org/10.3390/molecules15129473 - 22 Dec 2010
Cited by 12 | Viewed by 11797
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, [...] Read more.
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
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159 KiB  
Article
Aristolactams and Alkamides of Aristolochia gigantea
by Juliana C. Holzbach and Lucia M. X. Lopes
Molecules 2010, 15(12), 9462-9472; https://doi.org/10.3390/molecules15129462 - 21 Dec 2010
Cited by 44 | Viewed by 11199
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- [...] Read more.
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)
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180 KiB  
Article
Seasonal Variation in Total Phenolic and Flavonoid Contents and DPPH Scavenging Activity of Bellis perennis L. Flowers
by Tomáš Siatka and Marie Kašparová
Molecules 2010, 15(12), 9450-9461; https://doi.org/10.3390/molecules15129450 - 21 Dec 2010
Cited by 87 | Viewed by 13352
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 [...] Read more.
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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708 KiB  
Review
Application of Cycloaddition Reactions to the Syntheses of Novel Boron Compounds
by Yinghuai Zhu, Xiao Siwei, John A. Maguire and Narayan S. Hosmane
Molecules 2010, 15(12), 9437-9449; https://doi.org/10.3390/molecules15129437 - 21 Dec 2010
Cited by 5 | Viewed by 11119
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 [...] Read more.
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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174 KiB  
Article
Synthesis and Antitumor Activity of 3-Methyl-4-oxo-3,4-dihydroimidazo [5,1-d][1,2,3,5]tetrazine-8-carboxylates and -carboxamides
by Dan Liu, Jian-Guo Yang, Jie Cheng and Lin-Xiang Zhao
Molecules 2010, 15(12), 9427-9436; https://doi.org/10.3390/molecules15129427 - 20 Dec 2010
Cited by 8 | Viewed by 8453
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 [...] Read more.
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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114 KiB  
Article
Facile and Convenient Synthesis of New Thieno[2,3-b]-Thiophene Derivatives
by Yahia Nasser Mabkhot, Nabila Abd Elshafy Kheder and Abdullah Mohammad Al-Majid
Molecules 2010, 15(12), 9418-9426; https://doi.org/10.3390/molecules15129418 - 20 Dec 2010
Cited by 27 | Viewed by 8806
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
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158 KiB  
Article
Synthesis of 2-(4,6-Dimethoxy-1,3,5-triazin-2-yloxyimino) Derivatives: Application in Solution Peptide Synthesis
by Tarfah I. Al-Warhi, Hassan M.A. AL-Hazimi, Ayman El-Faham and Fernando Albericio
Molecules 2010, 15(12), 9403-9417; https://doi.org/10.3390/molecules15129403 - 20 Dec 2010
Cited by 8 | Viewed by 10462
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 [...] Read more.
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
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161 KiB  
Article
Insecticidal Activity of Essential Oil of Carum Carvi Fruits from China and Its Main Components against Two Grain Storage Insects
by Rui Fang, Cai Hong Jiang, Xiu Yi Wang, Hai Ming Zhang, Zhi Long Liu, Ligang Zhou, Shu Shan Du and Zhi Wei Deng
Molecules 2010, 15(12), 9391-9402; https://doi.org/10.3390/molecules15129391 - 20 Dec 2010
Cited by 119 | Viewed by 14280
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, [...] Read more.
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
427 KiB  
Communication
Frameshifting in the P6 cDNA Phage Display System
by Cindy Govarts, Klaartje Somers, Piet Stinissen and Veerle Somers
Molecules 2010, 15(12), 9380-9390; https://doi.org/10.3390/molecules15129380 - 20 Dec 2010
Cited by 6 | Viewed by 10124
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 [...] Read more.
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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271 KiB  
Article
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
by Yong Ai, Fa-Jun Song, Shao-Teng Wang, Qiang Sun and Ping-Hua Sun
Molecules 2010, 15(12), 9364-9379; https://doi.org/10.3390/molecules15129364 - 17 Dec 2010
Cited by 15 | Viewed by 7785
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 [...] Read more.
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
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163 KiB  
Article
Evaluation of the Bioactivity of Novel Spiroisoxazoline TypeCompounds against Normal and Cancer Cell Lines
by Nigar Najim, Yaser Bathich, Mazatulikhma Mat Zain, Ahmad Sazali Hamzah and Zurina Shaameri
Molecules 2010, 15(12), 9340-9353; https://doi.org/10.3390/molecules15129340 - 17 Dec 2010
Cited by 25 | Viewed by 8006
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). [...] Read more.
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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1017 KiB  
Article
The Influence of Mixed Activators on Ethylene Polymerization and Ethylene/1-Hexene Copolymerization with Silica-Supported Ziegler-Natta Catalyst
by Nichapat Senso, Supaporn Khaubunsongserm, Bunjerd Jongsomjit and Piyasan Praserthdam
Molecules 2010, 15(12), 9323-9339; https://doi.org/10.3390/molecules15129323 - 16 Dec 2010
Cited by 19 | Viewed by 10669
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 [...] Read more.
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
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276 KiB  
Article
Antioxidant Activity of Lignin Phenolic Compounds Extracted from Kraft and Sulphite Black Liquors
by Hélio Faustino, Nuno Gil, Cecília Baptista and Ana Paula Duarte
Molecules 2010, 15(12), 9308-9322; https://doi.org/10.3390/molecules15129308 - 16 Dec 2010
Cited by 132 | Viewed by 11658
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 [...] Read more.
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)
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244 KiB  
Article
A Novel Benzo[f][1,7]Naphthyridine Produced by Streptomyces Albogriseolus from Mangrove Sediments
by Xiao-Ling Li, Min-Juan Xu, Yi-Lei Zhao and Jun Xu
Molecules 2010, 15(12), 9298-9307; https://doi.org/10.3390/molecules15129298 - 15 Dec 2010
Cited by 31 | Viewed by 9717
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 [...] Read more.
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)
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222 KiB  
Article
Antimicrobial Activity of Sphingolipids Isolated from the Stems of Cucumber (Cucumis sativus L.)
by Jing Tang, Xiangjie Meng, Hao Liu, Jianglin Zhao, Ligang Zhou, Minghua Qiu, Xianming Zhang, Zhu Yu and Fuyu Yang
Molecules 2010, 15(12), 9288-9297; https://doi.org/10.3390/molecules15129288 - 15 Dec 2010
Cited by 37 | Viewed by 11800
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)
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311 KiB  
Review
Antioxidant and Anti-Inflammatory Activities of Essential Oils: A Short Review
by Maria Graça Miguel
Molecules 2010, 15(12), 9252-9287; https://doi.org/10.3390/molecules15129252 - 15 Dec 2010
Cited by 688 | Viewed by 43857
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 [...] Read more.
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
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224 KiB  
Review
[2+2+2] Cycloaddition Reactions of Macrocyclic Systems Catalyzed by Transition Metals. A Review
by Anna Pla-Quintana and Anna Roglans
Molecules 2010, 15(12), 9230-9251; https://doi.org/10.3390/molecules15129230 - 15 Dec 2010
Cited by 61 | Viewed by 13210
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 [...] Read more.
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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253 KiB  
Article
An Improved in Vivo Deuterium Labeling Method for Measuring the Biosynthetic Rate of Cytokinins
by Petr Tarkowski, Kristýna Floková, Kateřina Václavíková, Pavel Jaworek, Martin Raus, Anders Nordström, Ondřej Novák, Karel Doležal, Marek Šebela and Jitka Frébortová
Molecules 2010, 15(12), 9214-9229; https://doi.org/10.3390/molecules15129214 - 15 Dec 2010
Cited by 6 | Viewed by 8905
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 [...] Read more.
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)
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77 KiB  
Article
Alkaloids from Stems of Esenbeckia leiocarpa Engl. (Rutaceae) as Potential Treatment for Alzheimer Disease
by Elaine Monteiro Cardoso-Lopes, James Andreas Maier, Marcelo Rogério da Silva, Luis Octávio Regasini, Simone Yasue Simote, Norberto Peporine Lopes, José Rubens Pirani, Vanderlan da Silva Bolzani and Maria Cláudia Marx Young
Molecules 2010, 15(12), 9205-9213; https://doi.org/10.3390/molecules15129205 - 13 Dec 2010
Cited by 77 | Viewed by 11992
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 [...] Read more.
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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193 KiB  
Article
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
by Chen-Jiang Liu and Chuan-Ji Yu
Molecules 2010, 15(12), 9197-9204; https://doi.org/10.3390/molecules15129197 - 10 Dec 2010
Cited by 4 | Viewed by 6634
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 [...] Read more.
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
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221 KiB  
Article
Volatile Compounds of Young Wines from Cabernet Sauvignon, Cabernet Gernischet and Chardonnay Varieties Grown in the Loess Plateau Region of China
by Bao Jiang and Zhenwen Zhang
Molecules 2010, 15(12), 9184-9196; https://doi.org/10.3390/molecules15129184 - 10 Dec 2010
Cited by 157 | Viewed by 9166
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 [...] Read more.
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
181 KiB  
Article
Synthesis and Biological Activity of trans-Tiliroside Derivatives as Potent Anti-Diabetic Agents
by Yujin Zhu, Yanjun Zhang, Yi Liu, Hongwan Chu and Hongquan Duan
Molecules 2010, 15(12), 9174-9183; https://doi.org/10.3390/molecules15129174 - 10 Dec 2010
Cited by 34 | Viewed by 10298
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 [...] Read more.
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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171 KiB  
Article
Sonogashira Reaction of Aryl and Heteroaryl Halides with Terminal Alkynes Catalyzed by a Highly Efficient and Recyclable Nanosized MCM-41 Anchored Palladium Bipyridyl Complex
by Bo-Nan Lin, Shao-Hsien Huang, Wei-Yi Wu, Chung-Yuan Mou and Fu-Yu Tsai
Molecules 2010, 15(12), 9157-9173; https://doi.org/10.3390/molecules15129157 - 10 Dec 2010
Cited by 72 | Viewed by 11838
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 [...] Read more.
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)
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229 KiB  
Article
Antioxidant Activities of Total Phenols of Prunella vulgaris L. in Vitro and in Tumor-bearing Mice
by Liang Feng, Xiaobin Jia, Mao-Mao Zhu, Yan Chen and Feng Shi
Molecules 2010, 15(12), 9145-9156; https://doi.org/10.3390/molecules15129145 - 10 Dec 2010
Cited by 56 | Viewed by 11465
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 [...] Read more.
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
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279 KiB  
Article
Unexplored Nucleophilic Ring Opening of Aziridines
by Ana María Costero, Salvador Gil, Margarita Parra and Pablo Rodríguez
Molecules 2010, 15(12), 9135-9144; https://doi.org/10.3390/molecules15129135 - 10 Dec 2010
Cited by 2 | Viewed by 8443
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 [...] Read more.
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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207 KiB  
Review
Experimental Models for Assaying Microvascular Endothelial Cell Pathophysiology in Stroke
by Susanna Camós and Judith Mallolas
Molecules 2010, 15(12), 9104-9134; https://doi.org/10.3390/molecules15129104 - 10 Dec 2010
Cited by 30 | Viewed by 12411
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 [...] Read more.
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)
386 KiB  
Article
Structural Relationship and Binding Mechanisms of Five Flavonoids with Bovine Serum Albumin
by E-Hu Liu, Lian-Wen Qi and Ping Li
Molecules 2010, 15(12), 9092-9103; https://doi.org/10.3390/molecules15129092 - 9 Dec 2010
Cited by 130 | Viewed by 13303
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) [...] Read more.
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
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504 KiB  
Review
Biosynthesis of Anthocyanins and Their Regulation in Colored Grapes
by Fei He, Lin Mu, Guo-Liang Yan, Na-Na Liang, Qiu-Hong Pan, Jun Wang, Malcolm J. Reeves and Chang-Qing Duan
Molecules 2010, 15(12), 9057-9091; https://doi.org/10.3390/molecules15129057 - 9 Dec 2010
Cited by 480 | Viewed by 28973
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 [...] Read more.
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)
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227 KiB  
Article
Synthesis and Antiviral Activity of 5‑(4‑Chlorophenyl)-1,3,4-Thiadiazole Sulfonamides
by Zhuo Chen, Weiming Xu, Keming Liu, Song Yang, Huitao Fan, Pinaki S. Bhadury, De-Yu Huang and Yuping Zhang
Molecules 2010, 15(12), 9046-9056; https://doi.org/10.3390/molecules15129046 - 9 Dec 2010
Cited by 132 | Viewed by 11999
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, [...] Read more.
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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