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Open AccessArticle Development of a Sphingosylphosphorylcholine Detection System Using RNA Aptamers

by Katsunori Horii, Kazuya Omi, Yoshihito Yoshida, Yuka Imai, Nobuya Sakai, Asako Oka, Hiromi Masuda, Makio Furuichi, Tetsuji Tanimoto and Iwao Waga

Molecules 2010, 15(8), 5742-5755; doi:10.3390/molecules15085742

Received: 27 July 2010 / Revised: 16 August 2010 / Accepted: 17 August 2010 / Published: 20 August 2010

Cited by 7 | Viewed by 5762 | PDF Full-text (309 KB)

Abstract

Sphingosylphosphorylcholine (SPC) is a lysosphingolipid that exerts multiple functions, including acting as a spasmogen, as a mitogenic factor for various types of cells, and sometimes as an inflammatory mediator. Currently, liquid chromatography/tandem mass spectrometry (LC/MS/MS) is used for the quantitation of SPC. However,

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Sphingosylphosphorylcholine (SPC) is a lysosphingolipid that exerts multiple functions, including acting as a spasmogen, as a mitogenic factor for various types of cells, and sometimes as an inflammatory mediator. Currently, liquid chromatography/tandem mass spectrometry (LC/MS/MS) is used for the quantitation of SPC. However, because of the complicated procedures required it may not be cost effective, hampering its regular usage in a routine practical SPC monitoring. In this report, we have generated RNA aptamers that bind to SPC with high affinity using an in vitro selection procedure and developed an enzyme-linked aptamer assay system using the minimized SPC aptamer that can successfully distinguish SPC from the structurally related sphingosine 1-phosphate (S1P). This is the first case of the Systematic Evolution of Ligands by EXponential enrichment (SELEX) process being performed with a lysosphingolipid. The SPC aptamers would be valuable tools for the development of aptamer-based medical diagnosis and for elucidating the biological role of SPC. Full article

Open AccessArticle A Facile Synthesis of 3-Substituted 9H-Pyrido[3,4-b]indol-1(2H)-one Derivatives from 3-Substituted β-Carbolines

by Guowu Lin, Yue Wang, Qingfa Zhou, Weifang Tang, Jian Wang and Tao Lu

Molecules 2010, 15(8), 5680-5691; doi:10.3390/molecules15085680

Received: 2 August 2010 / Revised: 10 August 2010 / Accepted: 11 August 2010 / Published: 17 August 2010

Cited by 5 | Viewed by 6103 | PDF Full-text (369 KB)

Abstract

A mild and efficient two-step synthesis of 3-substituted β-carbolinone derivatives from 3-substituted β-carboline in good yields is described. A possible reaction mechanism for the formation of the skeleton of β-carbolin-1-one is proposed. The structures of these compounds were established by IR, ¹H-NMR,

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A mild and efficient two-step synthesis of 3-substituted β-carbolinone derivatives from 3-substituted β-carboline in good yields is described. A possible reaction mechanism for the formation of the skeleton of β-carbolin-1-one is proposed. The structures of these compounds were established by IR, ¹H-NMR, ¹³C-NMR, mass spectrometry and elemental analysis, as well as X-ray crystallographic analysis of 4-2 and 6-2. Full article

Open AccessArticle Antiplatelet Aggregation and Platelet Activating Factor (PAF) Receptor Antagonistic Activities of the Essential Oils of Five Goniothalamus Species

by Bushra Abdulkarim Moharam, Ibrahim Jantan, Fasihuddin bin Ahmad and Juriyati Jalil

Molecules 2010, 15(8), 5124-5138; doi:10.3390/molecules15085124

Received: 21 June 2010 / Revised: 22 July 2010 / Accepted: 23 July 2010 / Published: 29 July 2010

Cited by 7 | Viewed by 6208 | PDF Full-text (143 KB)

Abstract

Nine essential oils, hydrodistilled from different parts of five Goniothalamus species (G. velutinus Airy-Shaw, G. woodii Merr., G. clemensii Ban, G. tapis Miq. and G. tapisoides Mat Salleh) were evaluated for their ability to inhibit platelet aggregation in human whole

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Nine essential oils, hydrodistilled from different parts of five Goniothalamus species (G. velutinus Airy-Shaw, G. woodii Merr., G. clemensii Ban, G. tapis Miq. and G. tapisoides Mat Salleh) were evaluated for their ability to inhibit platelet aggregation in human whole blood using an electrical impedance method and their inhibitory effects on platelet activating factor (PAF) receptor binding with rabbit platelets using ³H-PAF as a ligand. The chemical composition of the oils was analyzed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). The bark oil of G. velutinus was the most effective sample as it inhibited both arachidonic acid (AA) and ADP-induced platelet aggregation with IC₅₀ values of 93.6 and 87.7 µg/mL, respectively. Among the studied oils, the bark oils of G. clemensii, G. woodii, G. velutinus and the root oil of G. tapis showed significant inhibitory effects on PAF receptor binding, with IC₅₀values ranging from 3.5 to 10.5 µg/mL. The strong PAF antagonistic activity of the active oils is related to their high contents of sesquiterpenes and sesquiterpenoids, and the individual components in the oils could possibly produce a synergistic effect in the overall antiplatelet activity of the oils. Full article

Open AccessArticle Anethole Isomerization and Dimerization Induced by Acid Sites or UV Irradiation

by Hans T. Castro, Jairo René Martínez and Elena Stashenko

Molecules 2010, 15(7), 5012-5030; doi:10.3390/molecules15075012

Received: 21 May 2010 / Revised: 21 June 2010 / Accepted: 25 June 2010 / Published: 22 July 2010

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Abstract

The formation of cis-anethole and various dimers as a result of the exposure of trans-anethole to microporous solid acids (dealuminated HY zeolites), or UV-Vis irradiation was established by means of high resolution gas chromatography coupled to mass spectrometry. 3,4-bis-(4-Methoxyphenyl)-(E)-hex-2-ene

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The formation of cis-anethole and various dimers as a result of the exposure of trans-anethole to microporous solid acids (dealuminated HY zeolites), or UV-Vis irradiation was established by means of high resolution gas chromatography coupled to mass spectrometry. 3,4-bis-(4-Methoxyphenyl)-(E)-hex-2-ene was the most abundant compound among eight different methoxyphenyl-disubstituted hexenes produced by electrophilic addition and elimination reactions induced by HY zeolites. (1a,2a,3b,4b)-1,2-bis(4-Methoxyphenyl)-3,4-dimethylcyclobutane was the principal component in the mixture of 5 methoxyphenyl-disubstituted cyclobutanes found, together with cis-anethole, after UV-Vis irradiation of a trans-anethole solution in toluene. Full article

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Open AccessReview Intelligent Chiral Sensing Based on Supramolecular and Interfacial Concepts

by Katsuhiko Ariga, Gary J. Richards, Shinsuke Ishihara, Hironori Izawa and Jonathan P. Hill

Sensors 2010, 10(7), 6796-6820; doi:10.3390/s100706796

Received: 17 June 2010 / Revised: 7 July 2010 / Accepted: 8 July 2010 / Published: 13 July 2010

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Abstract

Of the known intelligently-operating systems, the majority can undoubtedly be classed as being of biological origin. One of the notable differences between biological and artificial systems is the important fact that biological materials consist mostly of chiral molecules. While most biochemical processes routinely

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Of the known intelligently-operating systems, the majority can undoubtedly be classed as being of biological origin. One of the notable differences between biological and artificial systems is the important fact that biological materials consist mostly of chiral molecules. While most biochemical processes routinely discriminate chiral molecules, differentiation between chiral molecules in artificial systems is currently one of the challenging subjects in the field of molecular recognition. Therefore, one of the important challenges for intelligent man-made sensors is to prepare a sensing system that can discriminate chiral molecules. Because intermolecular interactions and detection at surfaces are respectively parts of supramolecular chemistry and interfacial science, chiral sensing based on supramolecular and interfacial concepts is a significant topic. In this review, we briefly summarize recent advances in these fields, including supramolecular hosts for color detection on chiral sensing, indicator-displacement assays, kinetic resolution in supramolecular reactions with analyses by mass spectrometry, use of chiral shape-defined polymers, such as dynamic helical polymers, molecular imprinting, thin films on surfaces of devices such as QCM, functional electrodes, FET, and SPR, the combined technique of magnetic resonance imaging and immunoassay, and chiral detection using scanning tunneling microscopy and cantilever technology. In addition, we will discuss novel concepts in recent research including the use of achiral reagents for chiral sensing with NMR, and mechanical control of chiral sensing. The importance of integration of chiral sensing systems with rapidly developing nanotechnology and nanomaterials is also emphasized. Full article

(This article belongs to the Special Issue Intelligent Sensors - 2010)

Open AccessReview Structures, Biological Activities and Phylogenetic Relationships of Terpenoids from Marine Ciliates of the Genus Euplotes

by Graziano Guella, Danielle Skropeta, Graziano Di Giuseppe and Fernando Dini

Mar. Drugs 2010, 8(7), 2080-2116; doi:10.3390/md8072080

Received: 1 June 2010 / Revised: 6 July 2010 / Accepted: 6 July 2010 / Published: 8 July 2010

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Abstract

In the last two decades, large scale axenic cell cultures of the marine species comprising the family Euplotidae have resulted in the isolation of several new classes of terpenoids with unprecedented carbon skeletons including the (i) euplotins, highly strained acetylated sesquiterpene hemiacetals; (ii)

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In the last two decades, large scale axenic cell cultures of the marine species comprising the family Euplotidae have resulted in the isolation of several new classes of terpenoids with unprecedented carbon skeletons including the (i) euplotins, highly strained acetylated sesquiterpene hemiacetals; (ii) raikovenals, built on the bicyclo[3.2.0]heptane ring system; (iii) rarisetenolides and focardins containing an octahydroazulene moiety; and (iv) vannusals, with a unique C30 backbone. Their complex structures have been elucidated through a combination of nuclear magnetic resonance spectroscopy, mass spectrometry, molecular mechanics and quantum chemical calculations. Despite the limited number of biosynthetic experiments having been performed, the large diversity of ciliate terpenoids has facilitated the proposal of biosynthetic pathways whereby they are produced from classical linear precursors. Herein, the similarities and differences emerging from the comparison of the classical chemotaxonomy approach based on secondary metabolites, with species phylogenesis based on genetic descriptors (SSU-rDNA), will be discussed. Results on the interesting ecological and biological properties of ciliate terpenoids are also reported. Full article

(This article belongs to the Special Issue Terpenoids of Marine Origin)

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Open AccessArticle Imaging Analysis of Carbohydrate-Modified Surfaces Using ToF-SIMS and SPRi

by Kathryn M. Bolles, Fang Cheng, Jesse Burk-Rafel, Manish Dubey and Daniel M. Ratner

Materials 2010, 3(7), 3948-3964; doi:10.3390/ma3073948

Received: 4 June 2010 / Revised: 28 June 2010 / Accepted: 1 July 2010 / Published: 7 July 2010

Cited by 7 | Viewed by 6844 | PDF Full-text (3581 KB) | HTML Full-text | XML Full-text

Abstract

Covalent modification of surfaces with carbohydrates (glycans) is a prerequisite for a variety of glycomics-based biomedical applications, including functional biomaterials, glycoarrays, and glycan-based biosensors. The chemistry of glycan immobilization plays an essential role in the bioavailability and function of the surface bound carbohydrate

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Covalent modification of surfaces with carbohydrates (glycans) is a prerequisite for a variety of glycomics-based biomedical applications, including functional biomaterials, glycoarrays, and glycan-based biosensors. The chemistry of glycan immobilization plays an essential role in the bioavailability and function of the surface bound carbohydrate moiety. However, the scarcity of analytical methods to characterize carbohydrate-modified surfaces complicates efforts to optimize glycan surface chemistries for specific applications. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is a surface sensitive technique suited for probing molecular composition at the biomaterial interface. Expanding ToF-SIMS analysis to interrogate carbohydrate-modified materials would increase our understanding of glycan surface chemistries and advance novel tools in the nascent field of glycomics. In this study, a printed glycan microarray surface was fabricated and subsequently characterized by ToF-SIMS imaging analysis. A multivariate technique based on principal component analysis (PCA) was used to analyze the ToF-SIMS dataset and reconstruct ToF-SIMS images of functionalized surfaces. These images reveal chemical species related to the immobilized glycan, underlying glycan-reactive chemistries, gold substrates, and outside contaminants. Printed glycoarray elements (spots) were also interrogated to resolve the spatial distribution and spot homogeneity of immobilized glycan. The bioavailability of the surface-bound glycan was validated using a specific carbohydrate-binding protein (lectin) as characterized by Surface Plasmon Resonance Imaging (SPRi). Our results demonstrate that ToF-SIMS is capable of characterizing chemical features of carbohydrate-modified surfaces and, when complemented with SPRi, can play an enabling role in optimizing glycan microarray fabrication and performance. Full article

(This article belongs to the Special Issue Advances in Surface Coatings)

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Open AccessCommunication Volatiles from a Rare Acer spp. Honey Sample from Croatia

by Igor Jerković, Zvonimir Marijanović, Mladenka Malenica-Staver and Dražen Lušić

Molecules 2010, 15(7), 4572-4582; doi:10.3390/molecules15074572

Received: 10 June 2010 / Accepted: 23 June 2010 / Published: 24 June 2010

Cited by 14 | Viewed by 5212 | PDF Full-text (161 KB)

Abstract

A rare sample of maple (Acer spp.) honey from Croatia was analysed. Ultrasonic solvent extraction (USE) using: 1) pentane, 2) diethyl ether, 3) a mixture of pentane and diethyl ether (1:2 v/v) and 4) dichloromethane as solvents was applied. All the extracts

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A rare sample of maple (Acer spp.) honey from Croatia was analysed. Ultrasonic solvent extraction (USE) using: 1) pentane, 2) diethyl ether, 3) a mixture of pentane and diethyl ether (1:2 v/v) and 4) dichloromethane as solvents was applied. All the extracts were analysed by GC and GC/MS. The most representative extracts were 3) and 4). Syringaldehyde was the most striking compound, being dominant in the extracts 2), 3) and 4) with percentages 34.5%, 33.1% and 35.9%, respectively. In comparison to USE results of other single Croatian tree honey samples (Robinia pseudoacacia L. nectar honey, Salix spp. nectar and honeydew honeys, Quercus frainetto Ten. honeydew as well as Abies alba Mill. and Picea abies L. honeydew) and literature data the presence of syringaldehyde, previously identified in maple sap and syrup, can be pointed out as a distinct characteristic of the Acer spp. honey sample. Headspace solid-phase microextraction (HS-SPME) combined with GC and GC/MS identified benzaldehyde (16.5%), trans-linalool oxide (20.5%) and 2-phenylethanol (14.9%) as the major compounds that are common in different honey headspace compositions. Full article

Open AccessArticle MALDI-TOF MS Analysis of Condensed Tannins with Potent Antioxidant Activity from the Leaf, Stem Bark and Root Bark of Acacia confusa

by Shu-Dong Wei, Hai-Chao Zhou, Yi-Ming Lin, Meng-Meng Liao and Wei-Ming Chai

Molecules 2010, 15(6), 4369-4381; doi:10.3390/molecules15064369

Received: 26 May 2010 / Revised: 10 June 2010 / Accepted: 12 June 2010 / Published: 15 June 2010

Cited by 22 | Viewed by 6879 | PDF Full-text (276 KB)

Abstract

The structures of the condensed tannins from leaf, stem bark and root bark of Acacia confusa were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, and their antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing/antioxidant

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The structures of the condensed tannins from leaf, stem bark and root bark of Acacia confusa were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, and their antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing/antioxidant power (FRAP) assays. The results showed that the condensed tannins from stem bark and root bark include propelargonidin and procyanidin, and the leaf condensed tannins include propelargonidin, procyanidin and prodelphinidin, all with the procyanidin dominating. The condensed tannins had different polymer chain lengths, varying from trimers to undecamers for leaf and root bark and to dodecamers for stem bark. The condensed tannins extracted from the leaf, stem bark and root bark all showed a very good DPPH radical scavenging activity and ferric reducing power. Full article

Open AccessArticle Evaluation of Carbohydrates in Natural and Cultured Cordyceps by Pressurized Liquid Extraction and Gas Chromatography Coupled with Mass Spectrometry

by Jia Guan, Feng-Qing Yang and Shao-Ping Li

Molecules 2010, 15(6), 4227-4241; doi:10.3390/molecules15064227

Received: 31 May 2010 / Revised: 9 June 2010 / Accepted: 10 June 2010 / Published: 11 June 2010

Cited by 33 | Viewed by 7031 | PDF Full-text (1150 KB)

Abstract

Free and polymeric carbohydrates in Cordyceps, a valued edible mushroom and well-known traditional Chinese medicine, were determined using stepwise pressurized liquid extraction (PLE) extraction and GC-MS. Based on the optimized PLE conditions, acid hydrolysis and derivatization, ten monosaccharides, namely rhamnose, ribose, arabinose,

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Free and polymeric carbohydrates in Cordyceps, a valued edible mushroom and well-known traditional Chinese medicine, were determined using stepwise pressurized liquid extraction (PLE) extraction and GC-MS. Based on the optimized PLE conditions, acid hydrolysis and derivatization, ten monosaccharides, namely rhamnose, ribose, arabinose, xylose, mannose, glucose, galactose, mannitol, fructose and sorbose in 13 samples of natural and cultured Cordyceps were qualitatively and quantitatively analyzed and compared with myo-inositol hexaacetate as internal standard. The results showed that natural C. sinensis contained more than 7.99% free mannitol and a small amount of glucose, while its polysaccharides were usually composed of mannose, glucose and galactose with a molar ratio of 1.00:16.61~3.82:1.60~1.28. However, mannitol in cultured C. sinensis and cultured C. militaris were less than 5.83%, and free glucose was only detected in a few samples, while their polysaccharides were mainly composed of mannose, glucose and galactose with molar ratios of 1.00:3.01~1.09:3.30~1.05 and 1.00:2.86~1.28:1.07~0.78, respectively. Natural and cultured Cordyceps could be discriminated by hierarchical clustering analysis based on its free carbohydrate contents. Full article

(This article belongs to the Special Issue Phytochemicals with Signaling, Medicinal and Therapeutic Properties)

Open AccessCommunication Anti-Proliferative Effect of Camellianin A in Adinandra nitida Leaves and Its Apoptotic Induction in Human Hep G2 and MCF-7 Cells

by Han Gao, Benguo Liu, Feng Liu and Yongsheng Chen

Molecules 2010, 15(6), 3878-3886; doi:10.3390/molecules15063878

Received: 1 April 2010 / Revised: 14 May 2010 / Accepted: 24 May 2010 / Published: 28 May 2010

Cited by 7 | Viewed by 5542 | PDF Full-text (304 KB)

Abstract

Leaves of Adinandra nitida constitute a kind of flavonoid-rich plant food. In this study, camellianin A, the main flavonoid in the leaves of Adinandra nitida,was prepared and identified by high performance liquid chromatography-photodiode array detector-electrospray ionization mass spectrometry (HPLC-PDA-ESI/MS). In the anticancer

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Leaves of Adinandra nitida constitute a kind of flavonoid-rich plant food. In this study, camellianin A, the main flavonoid in the leaves of Adinandra nitida,was prepared and identified by high performance liquid chromatography-photodiode array detector-electrospray ionization mass spectrometry (HPLC-PDA-ESI/MS). In the anticancer assay, it was found camellianin A could inhibit the proliferation of the human hepatocellular liver carcinoma Hep G2 and human breast adenocarcinoma MCF-7 cell lines in a dose-dependent manner and induce the significant increase of the G0/G1 cell population. After treated by camellianin A, phosphatidylserine of Hep G2 and MCF-7 cells could translocate significantly to the surface of the membrane. The increase of an early apoptotic population of Hep G2 and MCF-7 cells was observed. It was concluded that camellianin A not only affected the progress of the cell cycle, but also induced cells to enter into apoptosis. Full article

Open AccessArticle Multi-Element Analysis and Geochemical Spatial Trends of Groundwater in Rural Northern New York

by Michael O’Connor, Matt Zabik, Carol Cady, Brian Cousens and Jeffrey Chiarenzelli

Water 2010, 2(2), 217-238; doi:10.3390/w2020217

Received: 30 March 2010 / Revised: 20 May 2010 / Accepted: 20 May 2010 / Published: 28 May 2010

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Abstract

Samples from private wells (n = 169) throughout St. Lawrence County, NY were analyzed by ICP-MS multi-element techniques. St. Lawrence County spans three diverse bedrock terranes including Precambrian crystalline rocks of the Adirondack Lowlands (mostly paragneisses) and Highlands (mostly orthogneisses), as well as

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Samples from private wells (n = 169) throughout St. Lawrence County, NY were analyzed by ICP-MS multi-element techniques. St. Lawrence County spans three diverse bedrock terranes including Precambrian crystalline rocks of the Adirondack Lowlands (mostly paragneisses) and Highlands (mostly orthogneisses), as well as Paleozoic sedimentary rocks of the St. Lawrence Valley. An ArcGIS database was constructed and used to generate contour plots for elements across the county. Strontium isotopes and unique geochemical signatures were used to distinguish water from various geologic units. The results were consistent with a large (7,309 km²), sparsely populated (~110,000), rural region with diverse bedrock and glacial cover. Full article

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Open AccessArticle Oak (Quercus frainetto Ten.) Honeydew Honey—Approach to Screening of Volatile Organic Composition and Antioxidant Capacity (DPPH and FRAP Assay)

by Igor Jerković and Zvonimir Marijanović

Molecules 2010, 15(5), 3744-3756; doi:10.3390/molecules15053744

Received: 26 April 2010 / Revised: 17 May 2010 / Accepted: 24 May 2010 / Published: 25 May 2010

Cited by 25 | Viewed by 6925 | PDF Full-text (199 KB)

Abstract

Two samples of oak honeydew honey were investigated. Headspace solid-phase microextraction (HS-SPME) combined with GC and GC/MS enabled identification of the most volatile organic headspace compounds being dominated by terpenes(mainly cis- and trans-linalool oxides). The volatile and less-volatile organic composition of

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Two samples of oak honeydew honey were investigated. Headspace solid-phase microextraction (HS-SPME) combined with GC and GC/MS enabled identification of the most volatile organic headspace compounds being dominated by terpenes(mainly cis- and trans-linalool oxides). The volatile and less-volatile organic composition of the samples was obtained by ultrasonic assisted extraction (USE) with two solvents (1:2 (v/v) pentane -diethyl ether mixture and dichloromethane) followed by GC and GC/MS analysis. Shikimic pathway derivatives are of particular interest with respect to the botanical origin of honey and the most abundant was phenylacetic acid (up to 16.4%). Antiradical activity (DPPH assay) of the honeydew samples was 4.5 and 5.1 mmol TEAC/kg. Ultrasonic solvent extracts showed several dozen times higher antiradical capacity in comparison to the honeydew. Antioxidant capacity (FRAP assay) of honeydew samples was 4.8 and 16.1 mmol Fe²⁺/kg, while the solvent mixture extracts showed antioxidant activity of 374.5 and 955.9 Fe²⁺/kg, respectively, and the dichloromethane extracts 127.3 and 101.5 mmol Fe²⁺/kg. Full article

(This article belongs to the Special Issue Antioxidants)

Open AccessArticle Organic Extractives from Mentha spp. Honey and the Bee-Stomach: Methyl Syringate, Vomifoliol, Terpenediol I, Hotrienol and Other Compounds

by Igor Jerković, Gordana Hegić, Zvonimir Marijanović and Dragan Bubalo

Molecules 2010, 15(4), 2911-2924; doi:10.3390/molecules15042911

Received: 22 March 2010 / Revised: 13 April 2010 / Accepted: 20 April 2010 / Published: 22 April 2010

Cited by 22 | Viewed by 6918 | PDF Full-text (204 KB)

Abstract

The GC and GC/MS analyses of the solvent organic extractive from the stomach of the bees, having collected Mentha spp. nectar, revealed the presence of methyl syringate (6.6%), terpendiol I (5.0%) and vomifoliol (3.0%) that can be attributed to the plant origin. Other

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The GC and GC/MS analyses of the solvent organic extractive from the stomach of the bees, having collected Mentha spp. nectar, revealed the presence of methyl syringate (6.6%), terpendiol I (5.0%) and vomifoliol (3.0%) that can be attributed to the plant origin. Other major compounds from the bee-stomach were related to the composition of cuticular waxes and less to pheromones. Organic extractivesfrom Mentha spp. honey were obtained by solvent-free headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) and analyzed by GC and GC/MS. The major honey headspace compounds were hotrienol (31.1%–38.5%), 2-methoxy-4-methylphenol (0.5–6.0%), cis- and trans-linalool oxides (0.9–2.8%), linalool (1.0–3.1%) and neroloxide (0.9–1.9%). Methyl syringate was the most abundant compound (38.3-56.2%) in the honey solvent extractives followed by vomifoliol (7.0–26.6%). Comparison of the honey organic extractives with the corresponding bee-stomach extractive indicated that methyl syringate and vomofoliol were transferred to the honey while terpendiol I was partially transformed to hotrienol in ripened honey. Full article

Open AccessArticle Dendrimers Containing Ferrocene and Porphyrin Moieties: Synthesis and Cubic Non-Linear Optical Behavior

by Eric G. Morales-Espinoza, Karla E. Sanchez-Montes, Elena Klimova, Tatiana Klimova, Irina V. Lijanova, José L. Maldonado, Gabriel Ramos-Ortíz, Simón Hernández-Ortega and Marcos Martínez-García

Molecules 2010, 15(4), 2564-2575; doi:10.3390/molecules15042564

Received: 22 December 2009 / Revised: 6 February 2010 / Accepted: 30 March 2010 / Published: 12 April 2010

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Abstract

Dendrons with ferrocenyl ended groups joined by styryl moieties were attached to a porphyrin core. All the dendrons used for dendrimer synthesis showed trans configuration. The chemical structure of the first generation dendron was confirmed by X-ray crystallographic studies. The structure of the

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Dendrons with ferrocenyl ended groups joined by styryl moieties were attached to a porphyrin core. All the dendrons used for dendrimer synthesis showed trans configuration. The chemical structure of the first generation dendron was confirmed by X-ray crystallographic studies. The structure of the synthesized dendrimers was confirmed by ¹H- and ¹³C-NMR, electrospray mass spectrometry and elemental analysis. Cubic non-linear optical behavior of the ferrocene and porphyrin-containing dendrimers was studied in solid thin films by THG Maker-Fringe technique at 1,260 nm. Full article

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Open AccessArticle Is Yessotoxin the Main Phycotoxin in Croatian Waters?

by Živana Ninčević Gladan, Ivana Ujević, Anna Milandri, Ivona Marasović, Alfiero Ceredi, Silvia Pigozzi, Jasna Arapov, Sanda Skejić, Stjepan Orhanović and Igor Isajlović

Mar. Drugs 2010, 8(3), 460-470; doi:10.3390/md8030460

Received: 21 January 2010 / Revised: 8 February 2010 / Accepted: 20 February 2010 / Published: 5 March 2010

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Abstract

With the aim of investigating whether yessotoxin (YTX) is responsible for diarrhetic shellfish poisoning (DSP) events in Croatian waters, three different methods were combined: a modified mouse bioassay (MBA) that discriminates YTX from other DSP toxins, the enzyme-linked immunosorbent assay method (ELISA) and

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With the aim of investigating whether yessotoxin (YTX) is responsible for diarrhetic shellfish poisoning (DSP) events in Croatian waters, three different methods were combined: a modified mouse bioassay (MBA) that discriminates YTX from other DSP toxins, the enzyme-linked immunosorbent assay method (ELISA) and liquid chromatography-mass spectrometry (LC-MS/MS). Among 453 samples of mussels and seawater analyzed in 2007, 10 samples were DSP positive. Results obtained by the modified MBA method revealed that most of the samples were positive for YTX, with the exception of samples from Lim Bay (LB 1) The ELISA method also identified the presence of YTX in these samples. DSP toxin profiles showed the presence of okadaic acid (OA) in three, and YTX in four out of nine samples that were analyzed by LC-MS/MS. The phytoplankton community structure pattern revealed Lingulodinium polyedrum (Stein) Dodge, which was present in the water prior to and/or during toxicity events at low concentrations (80 to 1440 cells L^-1), as a potential YTX producing species. It is proposed that L. polyedrum cells accumulated in mussels and the subsequently observed toxicity may be related to metabolism after ingestion, resulting in carboxy YTX as the major analog in the mussel. Full article

(This article belongs to the Special Issue Algal Toxins)

Open AccessArticle Thermo-Exfoliated Graphite Containing CuO/Cu₂(OH)₃NO₃:(Co²⁺/Fe³⁺) Composites: Preparation, Characterization and Catalytic Performance in CO Conversion

by Elena V. Ischenko, Ludmila Yu. Matzui, Snezhanna V. Gayday, Ludmila L. Vovchenko, Tatyana V. Kartashova and Vladyslav V. Lisnyak

Materials 2010, 3(1), 572-584; doi:10.3390/ma3010572

Received: 17 November 2009 / Revised: 23 December 2009 / Accepted: 5 January 2010 / Published: 20 January 2010

Cited by 5 | Viewed by 12652 | PDF Full-text (714 KB) | HTML Full-text | XML Full-text

Abstract

Thermo-exfoliated graphite (TEG)/CuO/Cu₂(OH)₃NO₃:(Co²⁺/Fe³⁺) composites were prepared using a wet impregnation method and subsequent thermal treatment. The physicochemical characterization of the composites was carried out by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM)

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Thermo-exfoliated graphite (TEG)/CuO/Cu₂(OH)₃NO₃:(Co²⁺/Fe³⁺) composites were prepared using a wet impregnation method and subsequent thermal treatment. The physicochemical characterization of the composites was carried out by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Ar temperature-desorption techniques. The catalytic efficiency toward CO conversion to CO₂ was examined under atmospheric pressure. Characterization of species adsorbed over the composites taken after the activity tests were performed by means of temperature programmed desorption massspectrometry (TPD MS). (TEG)/CuO/Cu₂(OH)₃NO₃:(Co²⁺/Fe³⁺) composites show superior performance results if lower temperatures and extra treatment with H₂SO₄ or HNO₃ are used at the preparation stages. The catalytic properties enhancements can be related to the Cu₂(OH)₃NO₃ phase providing reaction centers for the CO conversion. It has been found that prevalence of low-temperature states of desorbed CO₂ over high-temperature ones in the TPD MS spectra is characteristic of the most active composite catalysts. Full article

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Open AccessReview Interest of Fluorescence Derivatization and Fluorescence Probe Assisted Post-column Detection of Phospholipids: A Short Review

by Hanadi Ibrahim, Eric Caudron, Athena Kasselouri and Pratrice Prognon

Molecules 2010, 15(1), 352-373; doi:10.3390/molecules15010352

Received: 2 December 2009 / Revised: 9 January 2010 / Accepted: 12 January 2010 / Published: 18 January 2010

Cited by 10 | Viewed by 10259 | PDF Full-text (489 KB)

Abstract

Phospholipids are essential constituents of all living cell membranes. There are many analytical methods available for the quantitative and qualitative determination of phospholipids, but since these molecules lack chromophores, common absorbance based methods are of limited use. Beside mass spectrometry, some less specific

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Phospholipids are essential constituents of all living cell membranes. There are many analytical methods available for the quantitative and qualitative determination of phospholipids, but since these molecules lack chromophores, common absorbance based methods are of limited use. Beside mass spectrometry, some less specific approaches that are routinely used are evaporative light scattering detection or fluorescence, which exhibit sufficient sensitivity. Here, we focus on fluorescence, which remains an interesting way to quantify phospholipids. Two ways of detecting phospholipids by fluorescence are possible coupled with separation techniques such as thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and capillary electrophoresis (CE): firstly, pre-column derivatization procedures and secondly, probe assisted post-column detection with suitable fluorescence reagents. In both cases, the common purpose is to increase the detection sensitivity. It is shown that, whereas pre-column derivatization is characterized by selectivity due to the chemical functionality of the analyte involved in the derivatization process, in supramolecular post-column derivatization, the selectivity only proceeds from the capacity of the lipid to involve supramolecular assemblies with a fluorescence probe. The aim of this review is to summarize available experiments concerning fluorescence detection of phospholipids. The interest and limitation of such detection approaches are discussed. Full article

(This article belongs to the Special Issue Phospholipids)

Open AccessArticle Determination of the Volatile Composition in Essential Oil of Descurainia sophia (L.) Webb ex Prantl (Flixweed) by Gas Chromatography/Mass Spectrometry (GC/MS)

by Jing Li, Xingang Liu, Fengshou Dong, Jun Xu, Yongquan Zheng and Weili Shan

Molecules 2010, 15(1), 233-240; doi:10.3390/molecules15010233

Received: 3 December 2009 / Revised: 6 January 2010 / Accepted: 7 January 2010 / Published: 8 January 2010

Cited by 16 | Viewed by 9396 | PDF Full-text (193 KB)

Abstract

Exhaustive hydro-distillation of Descurainia sophia (L.) Webb ex Prantl (flixweed) collected from two different locations (Cangzhou city-Sample 1 and Beijing city-Sample 2) gave in both cases yellowish colored oils in 0.31 and 0.26% yield, respectively. Detailed chemical composition of the essential oils was

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Exhaustive hydro-distillation of Descurainia sophia (L.) Webb ex Prantl (flixweed) collected from two different locations (Cangzhou city-Sample 1 and Beijing city-Sample 2) gave in both cases yellowish colored oils in 0.31 and 0.26% yield, respectively. Detailed chemical composition of the essential oils was analyzed by GC and GC/MS, and forty and thirty-eight compounds were identified. The results indicated that the most abundant component of Sample 1were cis-β-ocimene (20.1%), menthol (11.27%), neoisomenthyl acetate (3.5%), alloaromadendrene (2.28%) and longicyclene (2.25%). Compared with the constituents of Sample 1, several chemical compounds such as 1,8-cineole, α-eudesmol, cis, trans-farnesol and β-pinene were not detected in Sample 2 although it was similarly dominated by cis-β-ocimene (17.12%), menthol (10.7%) and neoisomenthyl acetate (2.96%). Final analysis of the chemical constituents in the essential oils of the two samples showed similarity in their chemical composition, but the relative content of all shared chemical constituents in Sample 2 was lower than that in Sample 1. Full article

Open AccessReview Sensing the Deadliest Toxin: Technologies for Botulinum Neurotoxin Detection

by Petr Čapek and Tobin J. Dickerson

Toxins 2010, 2(1), 24-53; doi:10.3390/toxins2010024

Received: 1 December 2009 / Revised: 17 December 2009 / Accepted: 22 December 2009 / Published: 7 January 2010

Abstract

Sensitive and rapid detection of botulinum neurotoxins (BoNTs), the most poisonous substances known to date, is essential for studies of medical applications of BoNTs and detection of poisoned food, as well as for response to potential bioterrorist threats. Currently, the most common method

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Sensitive and rapid detection of botulinum neurotoxins (BoNTs), the most poisonous substances known to date, is essential for studies of medical applications of BoNTs and detection of poisoned food, as well as for response to potential bioterrorist threats. Currently, the most common method of BoNT detection is the mouse bioassay. While this assay is sensitive, it is slow, quite expensive, has limited throughput and requires sacrificing animals. Herein, we discuss and compare recently developed alternative in vitro detection methods and assess their ability to supplement or replace the mouse bioassay in the analysis of complex matrix samples. Full article

(This article belongs to the Special Issue Neurotoxins of Biological Origin)

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Open AccessArticle Germacrene D, A Common Sesquiterpene in the Genus Bursera (Burseraceae)

by Koji Noge and Judith X. Becerra

Molecules 2009, 14(12), 5289-5297; doi:10.3390/molecules14125289

Received: 12 November 2009 / Revised: 15 December 2009 / Accepted: 15 December 2009 / Published: 15 December 2009

Cited by 16 | Viewed by 6546 | PDF Full-text (123 KB)

Abstract

The volatile components of the leaves of five Bursera species, B. copallifera, B. exselsa, B. mirandae, B. ruticola and B. fagaroides var. purpusii were determined by gas chromatography–mass spectrometry (GC–MS). Germacrene D was one of the predominant components (15.1–56.2%) of

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The volatile components of the leaves of five Bursera species, B. copallifera, B. exselsa, B. mirandae, B. ruticola and B. fagaroides var. purpusii were determined by gas chromatography–mass spectrometry (GC–MS). Germacrene D was one of the predominant components (15.1–56.2%) of all of these species. Germacrene D has also been found in other Bursera species and some species of Commiphora, the sister group of Bursera, suggesting that the production of germacrene D might be an ancient trait in the genus Bursera. Full article

Open AccessArticle New Cucurbitane Triterpenoids and Steroidal Glycoside from Momordica charantia

by Jie-Qing Liu, Jian-Chao Chen, Cui-Fang Wang and Ming-Hua Qiu

Molecules 2009, 14(12), 4804-4813; doi:10.3390/molecules14124804

Received: 26 October 2009 / Revised: 9 November 2009 / Accepted: 11 November 2009 / Published: 25 November 2009

Cited by 21 | Viewed by 9621 | PDF Full-text (477 KB)

Abstract

Three new cucurbitane triterpenoids 1–3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia. The structures of new compounds were determined to be 19(R)-n-butanoxy-5β,19-epoxycucurbita-6,23-diene-3β,25-diol 3-O-

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Three new cucurbitane triterpenoids 1–3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia. The structures of new compounds were determined to be 19(R)-n-butanoxy-5β,19-epoxycucurbita-6,23-diene-3β,25-diol 3-O-β-glucopyranoside (1), 23-O-β-allopyranosylecucurbita-5,24-dien-7α,3β,22(R),23(S)-tetraol 3-O-β-allopyranoside. (2), 23(R),24(S),25-trihydroxycucurbit-5-ene 3-O-{[β-glucopyranosyl(1→6)]-O-β-glucopyranosyl}-25-O-β-glucopyranoside (3), and 24(R)-stigmastan-3β,5α,6β-triol-25-ene 3-O-β-glucopyranoside (4), respectively. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments and chemical reactions. Full article

Open AccessReview Revisiting Plus-Strand DNA Synthesis in Retroviruses and Long Terminal Repeat Retrotransposons: Dynamics of Enzyme: Substrate Interactions

by Daniele Fabris, John P. Marino and Stuart F. J. Le Grice

Viruses 2009, 1(3), 657-677; doi:10.3390/v1030657

Received: 10 September 2009 / Revised: 28 October 2009 / Accepted: 4 November 2009 / Published: 4 November 2009

Cited by 3 | Viewed by 8242 | PDF Full-text (791 KB) | HTML Full-text | XML Full-text

Abstract

Although polypurine tract (PPT)-primed initiation of plus-strand DNA synthesis in retroviruses and LTR-containing retrotransposons can be accurately duplicated, the molecular details underlying this concerted series of events remain largely unknown. Importantly, the PPT 3’ terminus must be accommodated by ribonuclease H (RNase H)

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Although polypurine tract (PPT)-primed initiation of plus-strand DNA synthesis in retroviruses and LTR-containing retrotransposons can be accurately duplicated, the molecular details underlying this concerted series of events remain largely unknown. Importantly, the PPT 3’ terminus must be accommodated by ribonuclease H (RNase H) and DNA polymerase catalytic centers situated at either terminus of the cognate reverse transcriptase (RT), and in the case of the HIV-1 enzyme, ~70Å apart. Communication between RT and the RNA/DNA hybrid therefore appears necessary to promote these events. The crystal structure of the HIV-1 RT/PPT complex, while informative, positions the RNase H active site several bases pairs from the PPT/U3 junction, and thus provides limited information on cleavage specificity. To fill the gap between biochemical and crystallographic approaches, we review a multidisciplinary approach combining chemical probing, mass spectrometry, NMR spectroscopy and single molecule spectroscopy. Our studies also indicate that nonnucleoside RT inhibitors affect enzyme orientation, suggesting initiation of plus-strand DNA synthesis as a potential therapeutic target. Full article

(This article belongs to the Special Issue Retroviral Enzymes)

Open AccessArticle Chemical Composition and in Vitro Antimicrobial and Mutagenic Activities of Seven Lamiaceae Essential Oils

by Laura De Martino, Vincenzo De Feo and Filomena Nazzaro

Molecules 2009, 14(10), 4213-4230; doi:10.3390/molecules14104213

Received: 6 October 2009 / Revised: 20 October 2009 / Accepted: 20 October 2009 / Published: 20 October 2009

Cited by 43 | Viewed by 9481 | PDF Full-text (481 KB)

Abstract

Deeper knowledge of the potentiality of aromatic plants can provide results of economic importance for food and pharmacological industry. The essential oils of seven Lamiaceae species were analyzed by gas chromatography-mass spectrometry and assayed for their antibacterial, antifungal and mutagenic activities. Monoterpenes in

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Deeper knowledge of the potentiality of aromatic plants can provide results of economic importance for food and pharmacological industry. The essential oils of seven Lamiaceae species were analyzed by gas chromatography-mass spectrometry and assayed for their antibacterial, antifungal and mutagenic activities. Monoterpenes in the oils ranged between 82.47% (hyssop oil) and 97.48% (thyme oil), being mainly represented by oxygenated compounds. The antibacterial activity was evaluated against six pathogenic and five non-pathogenic bacterial strains. Oregano and thyme oils showed the strongest antibacterial activity against the pathogenic ones. The antifungal activity was evaluated against six fungal strains of agrifood interest: the oils tested exhibited variable degrees of activity. Two Salmonella typhimurium strains were used to assess the possible mutagenic activity. No oil showed mutagenic activity. Data obtained let us hypothesise that the use of essential oils could be a viable and safe way to decrease the utilisation of synthetic food preservatives. Further research is needed to obtain information regarding the practical effectiveness of essential oils to prevent the growth of food borne and spoiling microbes under specific application conditions. Full article

Open AccessArticle Two New Jaspamide Derivatives from the Marine Sponge Jaspis splendens

by Sherif S. Ebada, Victor Wray, Nicole J. De Voogd, Zhiwei Deng, Wenhan Lin and Peter Proksch

Mar. Drugs 2009, 7(3), 435-444; doi:10.3390/md7030435

Received: 21 August 2009 / Revised: 2 September 2009 / Accepted: 14 September 2009 / Published: 15 September 2009

Cited by 13 | Viewed by 7309 | PDF Full-text (158 KB) | HTML Full-text | XML Full-text

Abstract

Two new jaspamide derivatives 2 and 3, together with the parent compound jaspamide (1) have been isolated from the marine sponge Jaspis splendens collected in Kalimantan (Indonesia). The structures of the new compounds were unambiguously elucidated based on 1D and 2D NMR spectral

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Two new jaspamide derivatives 2 and 3, together with the parent compound jaspamide (1) have been isolated from the marine sponge Jaspis splendens collected in Kalimantan (Indonesia). The structures of the new compounds were unambiguously elucidated based on 1D and 2D NMR spectral data, mass spectrometry and comparison with jaspamide (1). The new derivatives inhibited the growth of mouse lymphoma (L5178Y) cell line in vitro with IC₅₀ values of <0.1 μg/mL. Full article

(This article belongs to the Special Issue Bioactive Compounds from Marine Sponges)

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Open AccessReview Monitoring Healthy Metabolic Trajectories with Nutritional Metabonomics

by Sebastiano Collino, François-Pierre J. Martin, Sunil Kochhar and Serge Rezzi

Nutrients 2009, 1(1), 101-110; doi:10.3390/nu1010101

Received: 3 August 2009 / Accepted: 31 August 2009 / Published: 4 September 2009

Cited by 10 | Viewed by 8196 | PDF Full-text (527 KB) | HTML Full-text | XML Full-text

Abstract

Metabonomics is a well established analytical approach for the analysis of physiological regulatory processes via the metabolic profiling of biofluids and tissues in living organisms. Its potential is fully exploited in the field of “nutrimetabonomics” that aims at assessing the metabolic effects of

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Metabonomics is a well established analytical approach for the analysis of physiological regulatory processes via the metabolic profiling of biofluids and tissues in living organisms. Its potential is fully exploited in the field of “nutrimetabonomics” that aims at assessing the metabolic effects of active ingredients and foods in individuals. Yet, one of the greatest challenges in nutrition research is to decipher the critical interactions between mammalian organisms and environmental factors, including the gut microbiota. “Nutrimetabonomics” is today foreseen as a powerful approach for future nutritional programs tailored at health maintenance and disease prevention. Full article

(This article belongs to the Special Issue Foodomics 2009)

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Open AccessArticle Intramolecular Transformations of 3-Cyanoamino- and 3-Cyanoimino-1,2-diferrocenylcyclopropenes

by Elena Ivanovna Klimova, Tatiana Klimova, Marcos Flores-Alamo, Leon Vladimirovich Backinowsky and Marcos Martinez Garcia

Molecules 2009, 14(9), 3161-3175; doi:10.3390/molecules14093161

Received: 13 June 2009 / Revised: 20 July 2009 / Accepted: 12 August 2009 / Published: 26 August 2009

Cited by 4 | Viewed by 6031 | PDF Full-text (419 KB)

Abstract

3-Cyanoamino-1,2- and -2,3-diferrocenylcyclopropenes 6a,b and 11a,b prepared by the reaction of diferrocenylcyclopropenylium salts with sodium cyanamide undergo smooth intramolecular transformations with both conservation of the three-membered ring [affording 3-cyanoimino-1,2-diferrocenylcyclopropene (8)] and its opening [affording Z-3-morpholino- and Z-3-piperidino-3-(cyanoimino)-1,2-diferrocenylprop-1-enes 7a,b and Z-3-cyanoimino-2,3-diferrocenyl-1-methylthioprop-1-ene

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3-Cyanoamino-1,2- and -2,3-diferrocenylcyclopropenes 6a,b and 11a,b prepared by the reaction of diferrocenylcyclopropenylium salts with sodium cyanamide undergo smooth intramolecular transformations with both conservation of the three-membered ring [affording 3-cyanoimino-1,2-diferrocenylcyclopropene (8)] and its opening [affording Z-3-morpholino- and Z-3-piperidino-3-(cyanoimino)-1,2-diferrocenylprop-1-enes 7a,b and Z-3-cyanoimino-2,3-diferrocenyl-1-methylthioprop-1-ene (10)]. 3-Cyano-imino-1,2-diferrocenylcyclopropene (8) reacts with hydrazine to form 3-amino-6-ferrocenyl-5-ferrocenylmethyl-1,2,4-triazine (12) and Z-2,3-diferrocenylacrylohydrazide N-cyanoimide (13) as a result of intramolecular transformations. The structures of the compounds obtained were determined by IR, ¹H- and ¹³C-NMR spectroscopy and mass spectrometry. The structures of compounds 7a and 10 were additionally confirmed by their X-ray diffraction analysis data. Full article

(This article belongs to the Special Issue Ferrocenes)

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Open AccessArticle Extraction with SPME and Synthesis of 2-Methyl-6-vinylpyrazine by a ‘One Pot’ Reaction Using Microwaves

by Norma Robledo, Jaime Escalante and René Arzuffi

Molecules 2009, 14(6), 2160-2166; doi:10.3390/molecules14062160

Received: 20 April 2009 / Revised: 30 May 2009 / Accepted: 2 June 2009 / Published: 15 June 2009

Cited by 2 | Viewed by 7098 | PDF Full-text (224 KB) | HTML Full-text | XML Full-text

Abstract

A synthesis of 2-methyl-6-vinylpyrazine was carried out by way of a ‘one pot’ reaction. In order to establish the efficiency of this synthesis the extraction of the volatiles released by male papaya fruit flies was performed by SPME (solid phase micro-extraction). The compound

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A synthesis of 2-methyl-6-vinylpyrazine was carried out by way of a ‘one pot’ reaction. In order to establish the efficiency of this synthesis the extraction of the volatiles released by male papaya fruit flies was performed by SPME (solid phase micro-extraction). The compound was separated and identified using GC/MSD (gas chromatography/mass spectrometry detector). Full article

(This article belongs to the Special Issue Microwave Assisted Synthesis)

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Open AccessArticle Synthesis and Molecular Descriptor Characterization of Novel 4-Hydroxy-chromene-2-one Derivatives as Antimicrobial Agents

by Milan Mladenović, Nenad Vuković, Neda Nićiforović, Slobodan Sukdolak and Slavica Solujić

Molecules 2009, 14(4), 1495-1512; doi:10.3390/molecules14041495

Received: 25 February 2009 / Revised: 26 March 2009 / Accepted: 7 April 2009 / Published: 14 April 2009

Cited by 24 | Viewed by 7822 | PDF Full-text (253 KB) | HTML Full-text | XML Full-text

Abstract

Several novel 4-hydroxy-chromene-2-one derivatives 2b-16b were easily prepared through condensation reactions with microwave heating and characterized by elemental analysis, IR, ¹H-NMR and mass spectrometry. Geometry optimization of these compounds was executed by PM3, PM5 and Minimize Energy methods to describe them via

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Several novel 4-hydroxy-chromene-2-one derivatives 2b-16b were easily prepared through condensation reactions with microwave heating and characterized by elemental analysis, IR, ¹H-NMR and mass spectrometry. Geometry optimization of these compounds was executed by PM3, PM5 and Minimize Energy methods to describe them via molecular descriptors. The antimicrobial activity of the synthesized compounds was evaluated against different microbial strains using two different methods: the diffusion method and the micro-dilution method. All data indicated that the products possess antimicrobial activity which depends on the nature of substituent attached to the benzopyran moiety. In general, after 24 h the MIC values of most tested coumarins was 0.13 mg/mL, but compounds 1 and 6b displayed the strongest antimicrobial activity on the tested cultures of bacteria after 48 h. Compound 13b has the strongest growth inhibitory potential on fungus C. albicans, tested by diffusion method,with an inhibition zone of 30-37 mm at a concentration of 150 µg/mL. The conclusion of this experiment is that the synthesized compounds have varied and different influence on different classes of bacteria and the fungus C. albicans. Full article

(This article belongs to the Special Issue Coumarins and Xanthones)

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Open AccessReview Toxin Detection by Surface Plasmon Resonance

by Vesna Hodnik and Gregor Anderluh

Sensors 2009, 9(3), 1339-1354; doi:10.3390/s9031339

Received: 3 November 2008 / Revised: 19 January 2009 / Accepted: 20 February 2009 / Published: 26 February 2009

Cited by 60 | Viewed by 9506 | PDF Full-text (178 KB) | HTML Full-text | XML Full-text

Abstract

Significant efforts have been invested in the past years for the development of analytical methods for fast toxin detection in food and water. Immunochemical methods like ELISA, spectroscopy and chromatography are the most used in toxin detection. Different methods have been linked, e.g.

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Significant efforts have been invested in the past years for the development of analytical methods for fast toxin detection in food and water. Immunochemical methods like ELISA, spectroscopy and chromatography are the most used in toxin detection. Different methods have been linked, e.g. liquid chromatography and mass spectrometry (LC-MS), in order to detect as low concentrations as possible. Surface plasmon resonance (SPR) is one of the new biophysical methods which enables rapid toxin detection. Moreover, this method was already included in portable sensors for on-site determinations. In this paper we describe some of the most common methods for toxin detection, with an emphasis on SPR. Full article

(This article belongs to the Special Issue Toxin Sensors)

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Open AccessCommunication Stereochemistry of 16a-Hydroxyfriedelin and 3-Oxo-16-methylfriedel-16-ene Established by 2D NMR Spectroscopy

by Lucienir Pains Duarte, Roqueline Rodrigues Silva de Miranda, Salomão Bento Vasconcelos Rodrigues Rodrigues, Grácia Divina De Fátima Silva, Sidney Augusto Vieira Filho and Vagner Fernandes Knupp

Molecules 2009, 14(2), 598-607; doi:10.3390/molecules14020598

Received: 20 November 2008 / Revised: 10 January 2009 / Accepted: 21 January 2009 / Published: 4 February 2009

Cited by 7 | Viewed by 8737 | PDF Full-text (90 KB) | HTML Full-text | XML Full-text

Abstract

Friedelin (1), 3b-friedelinol (2), 28-hydroxyfriedelin (3), 16a-hydroxyfriedelin (4), 30-hydroxyfriedelin (5) and 16a,28-dihydroxyfriedelin (6) were isolated through fractionation of the hexane extract obtained from branches of Salacia elliptica. After a week in CDCl₃ solution, 16a-hydroxyfriedelin (4) reacted turning into 3-oxo-16-methylfriedel-16-ene (7). This is

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Friedelin (1), 3b-friedelinol (2), 28-hydroxyfriedelin (3), 16a-hydroxyfriedelin (4), 30-hydroxyfriedelin (5) and 16a,28-dihydroxyfriedelin (6) were isolated through fractionation of the hexane extract obtained from branches of Salacia elliptica. After a week in CDCl₃ solution, 16a-hydroxyfriedelin (4) reacted turning into 3-oxo-16-methylfriedel-16-ene (7). This is the first report of a dehydration followed by a Nametkin rearrangement of a pentacyclic triterpene in CDCl₃ solution occurring in the NMR tube. These seven pentacyclic triterpenes was identified through NMR spectroscopy and the stereochemistry of compound 4 and 7 was established by 2D NMR (NOESY) spectroscopy and mass spectrometry (GC-MS). It is also the first time that all the ¹³C-NMR and 2D NMR spectral data are reported for compounds 4 and 7. Full article

(This article belongs to the Special Issue Triterpenes and Triterpenoids)

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Open AccessArticle Ethyl Carbamate in Alcoholic Beverages from Mexico (Tequila, Mezcal, Bacanora, Sotol) and Guatemala (Cuxa): Market Survey and Risk Assessment

by Dirk W. Lachenmeier, Fotis Kanteres, Thomas Kuballa, Mercedes G. López and Jürgen Rehm

Int. J. Environ. Res. Public Health 2009, 6(1), 349-360; doi:10.3390/ijerph6010349

Received: 19 December 2008 / Accepted: 16 January 2009 / Published: 20 January 2009

Cited by 30 | Viewed by 11673 | PDF Full-text (279 KB) | HTML Full-text | XML Full-text

Abstract

Ethyl carbamate (EC) is a recognized genotoxic carcinogen, with widespread occurrence in fermented foods and beverages. No data on its occurrence in alcoholic beverages from Mexico or Central America is available. Samples of agave spirits including tequila, mezcal, bacanora and sotol (n=110), and

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Ethyl carbamate (EC) is a recognized genotoxic carcinogen, with widespread occurrence in fermented foods and beverages. No data on its occurrence in alcoholic beverages from Mexico or Central America is available. Samples of agave spirits including tequila, mezcal, bacanora and sotol (n=110), and of the sugarcane spirit cuxa (n=16) were purchased in Mexico and Guatemala, respectively, and analyzed for EC. The incidence of EC contamination was higher in Mexico than in Guatemala, however, concentrations were below international guideline levels (<0.15 mg/L). Risk assessment found the Margin of Exposure (MOE) in line with that of European spirits. It is therefore unlikely that EC plays a role in high rates of liver cirrhosis reported in Mexico. Full article

(This article belongs to the Special Issue Environmental Research on Alcohol: Public Health Perspectives)

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Open AccessArticle HPLC, NMR and MALDI-TOF MS Analysis of Condensed Tannins from Lithocarpus glaber Leaves with Potent Free Radical Scavenging Activity

by Liang Liang Zhang and Yi Ming Lin

Molecules 2008, 13(12), 2986-2997; doi:10.3390/molecules13122986

Received: 5 September 2008 / Revised: 23 November 2008 / Accepted: 2 December 2008 / Published: 4 December 2008

Cited by 26 | Viewed by 8475 | PDF Full-text (249 KB) | HTML Full-text | XML Full-text

Abstract

Using acid-catalyzed degradation in the presence of cysteamine, the condensed tannins from Lithocarpus glaber leaves were characterized, following thiolysis, by means of reversed-phase HPLC, ¹³C-NMR and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analyses. The thiolysis reaction products showed

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Using acid-catalyzed degradation in the presence of cysteamine, the condensed tannins from Lithocarpus glaber leaves were characterized, following thiolysis, by means of reversed-phase HPLC, ¹³C-NMR and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analyses. The thiolysis reaction products showed the presence of the procyanidin (PC) and prodelphinidin (PD) structures. The ¹³C-NMR spectrum revealed that the condensed tannins were comprised of PD (72.4%) and PC (27.6%), and with a greater content of cis configuration rather than the trans configuration of C2–C3. The MALDI-TOF MS analysis proved the presence of PD units, and the maximum degree of polymerization (DP) was an undecamer. The antioxidant activity of condensed tannins from L. glaber leaves was evaluated by using a free radical scavenging activity assay. Full article

Open AccessArticle Spectral Characterization of Degradation Impurities of Paroxetine Hydrochloride Hemihydrate

by Nirmala MUNIGELA, J. Moses BABU, Anjaneyulu YERRAMILLI, Naveen Kumar KOLLA, Vyas KRISHNAMURTHY and Vijay Vittal MATHAD

Sci. Pharm. 2008, 76(4), 653-662; doi:10.3797/scipharm.0808-08 (registering DOI)

Received: 10 August 2008 / Accepted: 14 September 2008 / Published: 23 September 2008

Cited by 1 | Viewed by 88 | PDF Full-text (316 KB)

Abstract

Two unknown impurities were detected in stressed samples (by hydrochloric acid and hydrogen peroxide) of paroxetine hydrochloride hemihydrate (an active pharmaceutical ingredient – API) using a gradient reversed-phase high performance liquid chromatography (HPLC). These impurities were enriched and were present up to 30%

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Two unknown impurities were detected in stressed samples (by hydrochloric acid and hydrogen peroxide) of paroxetine hydrochloride hemihydrate (an active pharmaceutical ingredient – API) using a gradient reversed-phase high performance liquid chromatography (HPLC). These impurities were enriched and were present up to 30% in the degraded sample. The impurities were isolated from the degraded sample by column purification. Spectral data of the isolated impurities were collected. Based on the spectral data of two dimensional nuclear magnetic spectroscopy (2D-NMR) and mass spectrometry (MS) Impurity-1 and Impurity-2 were characterized as (3S,4R)-3-{[(6-chloro-1,3-benzodioxol-5-yl)oxy]methyl}-4-(4-fluorophenyl)piperidine and [(3S,4R)-4-(4-fluorophenyl)piperidin-3-yl]methanol respectively. Full article

Open AccessArticle Evaluation of Flavonoids and Furanocoumarins from Citrus bergamia (Bergamot) Juice and Identification of New Compounds

by Claudio Gardana, Federico Nalin and Paolo Simonetti

Molecules 2008, 13(9), 2220-2228; doi:10.3390/molecules13092220

Received: 1 August 2008 / Revised: 1 September 2008 / Accepted: 9 September 2008 / Published: 18 September 2008

Cited by 20 | Viewed by 13582 | PDF Full-text (326 KB) | HTML Full-text | XML Full-text

Abstract

Bergamot juice (BJ) contains different classes of flavonoids (e.g. flavanones and flavones) that can exert beneficial effects on human health. The aim of this study was to evaluate the qualitative and quantitative composition of a BJ obtained from fruits harvested in Southern Italy

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Bergamot juice (BJ) contains different classes of flavonoids (e.g. flavanones and flavones) that can exert beneficial effects on human health. The aim of this study was to evaluate the qualitative and quantitative composition of a BJ obtained from fruits harvested in Southern Italy (Calabria) at the end of their maturation period. The identity of several flavonoids and furanocoumarins was assessed by co-chromatography, UV spectra and molecular weight comparison. The unknown compounds were dissociated by induced collision (CID-MS) and their identity established through the characteristic ions product. By this approach a complete profile of about twenty compounds (furano-coumarins, flavonoids C- and O-glycosides) present in BJ was obtained. Furthermore, three acylated flavanones, present in amounts of 20.1±1.1, 89.3±2.2 and 190.1±3.1 mg/L, respectively, and which seem to correspond to di-oxalate derivatives of neoeriocitrin, naringin and neohesperidin, were identified for the first time in BJ. The other main flavanones were naringin, neohesperidin and neoeriocitrin, and their content was 167.5±1.8, 123.9±1.7 and 73.3±1.6 mg/L, respectively. Concerning flavones, the total amount in BJ was about 160 mg/L and the main ones were vicenin-2, stellarin-2, rhoifolin and neodiosmin. Bergapten and bergamottin were the primary furanocoumarins in BJ and their amounts were 9.0±0.4 and 18.2±0.5 mg/L, respectively. Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

Open AccessCommunication Chemical Composition, Antifungal and Antitumor Properties of Ether Extracts of Scapania verrucosa Heeg. and its Endophytic Fungus Chaetomium fusiforme

by Lei Guo, Jin-zhong Wu, Ting Han, Tong Cao, Khalid Rahman and Lu-ping Qin

Molecules 2008, 13(9), 2114-2125; doi:10.3390/molecules13092114

Received: 19 June 2008 / Revised: 15 August 2008 / Accepted: 3 September 2008 / Published: 4 September 2008

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Abstract

An endophytic fungus Chaetomium fusiforme was obtained from a liverwort, Scapania verrucosa. A comparison of the constituents of the ether extracts between S. verrucosa and the C. fusiforme culture was investigated by gas chromatography-mass spectrometry (GC/MS). The yield of ether extract based

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An endophytic fungus Chaetomium fusiforme was obtained from a liverwort, Scapania verrucosa. A comparison of the constituents of the ether extracts between S. verrucosa and the C. fusiforme culture was investigated by gas chromatography-mass spectrometry (GC/MS). The yield of ether extract based on dried plant material was 0.6% and 59 compounds were found in S. verrucosa. (+)-Aromadendrene (9.12%), hexadecanoic acid (6.92%), 6-isopropenyl-4,8a-dimethyl-1,2,3,5,6,7,8,8a-octahydro-naphthalen-2-ol (5.97%), s-tetrachloroethane (5.61%) and acetic acid (5.30%) were found to be the most abundant components among the 49 characterized compounds in S. verrucosa, which represented 84.64% of the total extract. However, the constituents of the cultured endophyte extract contained mainly acetic acid (35.05%), valeric acid, 3-methyl-, methyl ester (21.25%), and butane-2, 3-diol (12.24%). Although the extracts of S. verrucosa and its endophyte showed little chemical composition correlation, both of them demonstrated antifungal and antitumor activities. Furthermore, C. fusiforme has displayed a wider range of antimicrobial and antitumor activities, which were better than the host plant. These results could support the suggestion of endophytes as an alternative of the host for medicinal activity. Full article

Open AccessArticle Characterization of Aroma Active Compounds in Fruit Juice and Peel Oil of Jinchen Sweet Orange Fruit (Citrus sinensis (L.) Osbeck) by GC-MS and GC-O

by Yu Qiao, Bi Jun Xie, Yan Zhang, Yun Zhang, Gang Fan, Xiao Lin Yao and Si Yi Pan

Molecules 2008, 13(6), 1333-1344; doi:10.3390/molecules13061333

Received: 20 April 2008 / Revised: 19 May 2008 / Accepted: 19 May 2008 / Published: 12 June 2008

Cited by 65 | Viewed by 11477 | PDF Full-text (240 KB) | HTML Full-text | XML Full-text

Abstract

Gas chromatography-mass spectrometry (GC-MS) and gas chromatographyolfactometry (GC-O) were used to determine the aromatic composition and aroma active compounds of fruit juice and peel oil of Jinchen sweet orange fruit. Totals of 49 and 32 compounds were identified in fruit juice and peel

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Gas chromatography-mass spectrometry (GC-MS) and gas chromatographyolfactometry (GC-O) were used to determine the aromatic composition and aroma active compounds of fruit juice and peel oil of Jinchen sweet orange fruit. Totals of 49 and 32 compounds were identified in fruit juice and peel oil, respectively. GC-O was performed to study the aromatic profile of Jinchen fruit juice and peel oil. A total of 41 components appeared to contribute to the aroma of fruit juice and peel oil. Twelve components were the odorants perceived in both samples. The aromatic compositions of fruit juice were more complex than that of peel oil. Ethyl butanoate, β-myrcene, octanal, linalool, α-pinene, and decanal were found to be responsible for the aromatic notes in fruit juice and peel oil. Nineteen components have been perceived only in the juice and ten compounds were described as aromatic components of only the peel oil by the panelists. These differences lead to the different overall aroma between fruit juice and peel oil. Full article

Open AccessArticle Headspace Solid Phase Micro Extraction Gas Chromatographic Determination of Fenthion in Human Serum

by Konstantinos M. Kasiotis, Helen Souki, Angelos N. Tsakirakis, Haris Carageorgiou, Spiridon A. Theotokatos, Serkos A. Haroutounian and Kyriaki Machera

Int. J. Mol. Sci. 2008, 9(5), 906-913; doi:10.3390/ijms9050906

Received: 15 April 2008 / Revised: 22 May 2008 / Accepted: 23 May 2008 / Published: 23 May 2008

Cited by 9 | Viewed by 4427 | PDF Full-text (191 KB) | HTML Full-text | XML Full-text

Abstract

A simple and effective analytical procedure was developed for the determination of fenthion residues in human serum samples. The sample treatment was performed using the headspace solid-phase micro extraction with polyacrylate fiber, which has the advantage to require low amount of serum (1

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A simple and effective analytical procedure was developed for the determination of fenthion residues in human serum samples. The sample treatment was performed using the headspace solid-phase micro extraction with polyacrylate fiber, which has the advantage to require low amount of serum (1 mL) without tedious pre-treatment. The quantification of fenthion was carried out by gas chromatography-mass spectrometry and the recoveries ranged from 79 to 104% at two spiking levels for 6 replicates. Detection and quantification limits were calculated as 1.51 and 4.54 ng/mL of serum respectively. Two fenthion metabolites − fenoxon and fenthion–sulfoxide − were also identified. Full article

Open AccessArticle Report on the First Detection of Pectenotoxin-2, Spirolide-A and Their Derivatives in French Shellfish

by Zouher Amzil, Manoella Sibat, Florence Royer, Nadine Masson and Eric Abadie

Mar. Drugs 2007, 5(4), 168-179; doi:10.3390/md504168

Received: 16 October 2007 / Accepted: 21 November 2007 / Published: 23 November 2007

Cited by 41 | Viewed by 5592 | PDF Full-text (145 KB) | HTML Full-text | XML Full-text

Abstract

In the context of the French Phytoplankton and Phycotoxins MonitoringNetwork (REPHY) programme, shellfish samples were harvested from different locationswhere harmful algae blooms were known to have occurred. For all shellfish samples foundpositive by the mouse bioassay for diarrhetic shellfish poisoning (DSP) toxins, liquidchromatography

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In the context of the French Phytoplankton and Phycotoxins MonitoringNetwork (REPHY) programme, shellfish samples were harvested from different locationswhere harmful algae blooms were known to have occurred. For all shellfish samples foundpositive by the mouse bioassay for diarrhetic shellfish poisoning (DSP) toxins, liquidchromatography (LC) coupled with mass spectrometry (MS) was used to search for thefollowing lipophilic toxins: okadaic acid (OA), dinophysistoxins (DTXs), pectenotoxins(PTXs), azaspiracids (AZAs), yessotoxins (YTXs), spirolides (SPXs) and gymnodimines(GYMs). In order to investigate the presence of acyl-OAs and/or acyl-DTX-1,-2 (DTX-3),alkaline hydrolysis was performed on all samples, and LC/MS analyses were carried out onthe samples before and after hydrolysis. The results revealed different lipophilic toxinprofiles as a function of the shellfish sampling location. The primary finding was that all ofthe samples contained OA and acyl-OA. In addition, other lipophilic toxins were found inshellfish samples: DTX-2, acyl-DTX-2 and SPXs (SPX-A, SPX-desMeC) on the Atlanticcoast (Southern Brittany, Arcachon), and pectenotoxins (PTX-2, PTX-2-seco-acid and 7-epi-PTX-2-seco-acid) on the Mediterranean coast (Thau lagoon, the island of Corsica).This paper reports on the first detection of PTX-2, SPX-A and their derivatives in Frenchshellfish. Full article

(This article belongs to the Special Issue Marine Toxins)

Open AccessArticle Genotoxicity of Air Borne Particulates Assessed by Comet and the Salmonella Mutagenicity Test in Jeddah, Saudi Arabia

by Sufian M. ElAssouli, Mohamed H. AlQahtani and Waleed Milaat

Int. J. Environ. Res. Public Health 2007, 4(3), 216-223; doi:10.3390/ijerph2007030004

Received: 4 September 2007 / Accepted: 22 September 2007 / Published: 30 September 2007

Cited by 18 | Viewed by 6588 | PDF Full-text (167 KB) | HTML Full-text | XML Full-text

Abstract

Fine airborne respirable particulates less than 10 micrometer (PM10) are considered one of the top environmental public health concerns, since they contain polycyclic aromatic hydrocarbons (PAHs) which are among the major carcinogenic compounds found in urban air. The objective of this study is

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Fine airborne respirable particulates less than 10 micrometer (PM10) are considered one of the top environmental public health concerns, since they contain polycyclic aromatic hydrocarbons (PAHs) which are among the major carcinogenic compounds found in urban air. The objective of this study is to assess the genotoxicity of the ambient PM10 collected at 11 urban sites in Jeddah, Saudi Arabia. The PM10 extractable organic matter (EOM) was examined for its genotoxicity by the single cell gel electrophoresis (SCGE) comet assay and the Salmonella mutagenicity (Ames) test .Gas chromatography-mass spectrometry was used to quantify 16 PAH compounds in four sites. Samples from oil refinery and heavy diesel vehicles traffic sites showed significant DNA damage causing comet in 20-44% of the cells with tail moments ranging from 0.5-2.0 compared to samples from petrol driven cars and residential area, with comet in less than 2% of the cells and tail moments of < 0.02.In the Ames test, polluted sites showed indirect mutagenic response and caused 20-56 rev/ m³, mean while residential and reference sites caused 2-15 rev /m³. The genotoxicity of the EOM in both tests directly correlated with the amount of organic particulate and the PAHs concentrations in the air samples. The PAHs concentrations ranged between 0.83 ng/m³ in industrial and heavy diesel vehicles traffic sites to 0.18 ng /m³ in the residential area. Benzo(ghi)pyrene was the major PAH components and at one site it represented 65.4 % of the total PAHs. Samples of the oil refinery site were more genotoxic in the SCGE assay than samples from the heavy diesel vehicles traffic site, despite the fact that both sites contain almost similar amount of PAHs. The opposite was true for the mutagenicity in the Ames test. This could be due to the nature of the EOM in both sites. These findings confirm the genotoxic potency of the PM10 organic extracts to which urban populations are exposed. Full article

Open AccessCommunication Preparative Separation and Identification of the Flavonoid Phlorhizin from the Crude Extract of Lithocarpus Polystachyus Rehd

by Huaqiang Dong, Zhengxiang Ning, Lijing Yu, Lin Li, Lichao Lin and Jianbo Huang

Molecules 2007, 12(3), 552-562; doi:10.3390/12030552

Received: 6 February 2007 / Revised: 13 March 2007 / Accepted: 13 March 2007 / Published: 20 March 2007

Cited by 23 | Viewed by 7308 | PDF Full-text (100 KB) | HTML Full-text | XML Full-text

Abstract

The flavonoid phlorhizin is abundant in the leaves of Sweet Tea(ST, Lithocarpus Polystachyus Rehd). Phlorhizinwas preparatively separated and purified from a crude ST extract containing 40% total flavonoids by static adsorption and dynamic desorption on ADS-7 macroporous resin and neutral alumina column chromatography.

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The flavonoid phlorhizin is abundant in the leaves of Sweet Tea(ST, Lithocarpus Polystachyus Rehd). Phlorhizinwas preparatively separated and purified from a crude ST extract containing 40% total flavonoids by static adsorption and dynamic desorption on ADS-7 macroporous resin and neutral alumina column chromatography. Only water and ethanol were used as solvents and eluants throughout the whole separation and purification process. Using a phlorhizin standard as the reference compound, the target compound separated from the crude ST extracts was analyzed by thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and electrosprayionization mass spectrometry (EIS-MS) and identified as 99.87% pure (by HPLC-UV) phlorhizin. The results showed that 10g of the targetcompound could be obtained from 40g of the crude extracts in a single operation, indicating a 40% recovery. Therefore, this represents an efficientand environmentally-friendly technology for separating and purifying phlorhizinfrom ST leaves. Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

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Open AccessArticle Phenolic Antioxidants Identified by ESI-MS from Yerba Maté (Ilex paraguariensis) and Green Tea (Camelia sinensis) Extracts

by Deborah H Bastos, Luciane A Saldanha, Rodrigo R Catharino, Alexandra Sawaya, Ildenize B Cunha, Patricia O Carvalho and Marcos N Eberlin

Molecules 2007, 12(3), 423-432; doi:10.3390/12030423

Received: 21 December 2006 / Revised: 3 March 2007 / Accepted: 4 March 2007 / Published: 12 March 2007

Cited by 147 | Viewed by 14878 | PDF Full-text (160 KB) | HTML Full-text | XML Full-text

Abstract

Aqueous extracts of green yerba maté (Ilex paraguariensis) and green tea (Camellia sinensis) are good sources of phenolic antioxidants, as already described in the literature. The subject of this study were organic extracts from yerba maté, both green and

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Aqueous extracts of green yerba maté (Ilex paraguariensis) and green tea (Camellia sinensis) are good sources of phenolic antioxidants, as already described in the literature. The subject of this study were organic extracts from yerba maté, both green and roasted, and from green tea. Their phenolic profiles were characterized by direct infusion electrospray insertion mass spectrometry (ESI-MS) and their free radical scavenging activity was determined by the DPPH assay. Organic extracts containing phenolic antioxidants might be used as natural antioxidants by the food industry, replacing the synthetic phenolic additives used nowadays. Ethanolic and aqueous extracts from green yerba maté, roasted yerba maté and green tea showed excellent DPPH scavenging activity (>89%). The ether extracts from green and roasted yerba maté displayed a weak scavenging activity, different from the behavior observed for the green tea ether extract. The main phenolic compounds identified in green yerba maté water and ethanolic extracts were: caffeic acid, quinic acid, caffeoyl glucose, caffeoylquinic acid, feruloylquinic acid, dicaffeoylquinic acid and rutin. After the roasting process two new compounds were formed: caffeoylshikimic acid and dicaffeoylshikimic acid. The ethanolic extracts from yerba maté, both roasted and green, with lower content of phenolic compounds (3.80 and 2.83 mg/mL) presented high antioxidant activity and even at very low phenolic concentrations, ether extract from GT (0.07 mg/mL) inhibited DPPH over 90%. Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

Open AccessArticle Acylated Flavone Glycosides from the Roots of Saussurea lappa and Their Antifungal Activity

by Kolisetty Sambasiva Rao, Goriparthi Venu Babu and Yemireddy Venkata Ramnareddy

Molecules 2007, 12(3), 328-344; doi:10.3390/12030328

Received: 14 November 2006 / Revised: 20 February 2007 / Accepted: 21 February 2007 / Published: 7 March 2007

Cited by 13 | Viewed by 4806 | PDF Full-text (180 KB) | HTML Full-text | XML Full-text

Abstract

The isolation of four novel acylated flavonoid glycosides from the roots of Saussurea lappa and their identification using a combination of 1D and 2D NMR and mass spectrometry is described. The in vitro antifungal and antibacterial activities of the isolated compounds and their

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The isolation of four novel acylated flavonoid glycosides from the roots of Saussurea lappa and their identification using a combination of 1D and 2D NMR and mass spectrometry is described. The in vitro antifungal and antibacterial activities of the isolated compounds and their mixture were tested on nine fungal and four bacterial strains, using the microdilution method. The compounds and mixture showed moderate to high antifungal activity against most of the fungi tested, compared to a miconazole standard, while only one compound and the mixture showed antibacterial activity against all strains tested. Full article

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Open AccessArticle Reactions of 9-Alkyl-3-aminocarbazoles with Ethyl-3-oxo-butanoate and Identification of the Products Obtained

by Birute Sapijanskaite, Ytautas Mickevicius and Gema Mikulskiene

Molecules 2006, 11(1), 72-80; doi:10.3390/11010072

Received: 17 March 2005 / Revised: 19 October 2005 / Accepted: 20 October 2005 / Published: 31 January 2006

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Abstract

The reactions in benzene of 9-alkyl-3-aminocarbazoles with ethyl-3-oxobutanoateyielded ethyl-3-[(9-alkyl-9H-carbazol-3-yl)amino]but-2-enoate condensation products or N-(9-ethyl-9H-carbazol-3-yl)-3-oxobutanamide acylation products. The condensation productswere cyclized to the corresponding 4,7-dihydro-pyrido[2,3-c]-carbazol-1-ones upon heatingin mineral oil at 240-250 °C. The structures of the synthesized compounds were investigatedby IR, mass spectrometry, ¹H-

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The reactions in benzene of 9-alkyl-3-aminocarbazoles with ethyl-3-oxobutanoateyielded ethyl-3-[(9-alkyl-9H-carbazol-3-yl)amino]but-2-enoate condensation products or N-(9-ethyl-9H-carbazol-3-yl)-3-oxobutanamide acylation products. The condensation productswere cyclized to the corresponding 4,7-dihydro-pyrido[2,3-c]-carbazol-1-ones upon heatingin mineral oil at 240-250 °C. The structures of the synthesized compounds were investigatedby IR, mass spectrometry, ¹H- and ¹³C-NMR spectroscopy and MM2 molecular mechanicsand AM1 semi-empirical quantum mechanical methods. Full article

Open AccessArticle Isolation and Structure Elucidation of a Novel Yellow Pigment from the Marine Bacterium Pseudoalteromonas tunicata

by A. Franks, P. Haywood, C. Holmström, S. Egan, S. Kjelleberg and N. Kumar

Molecules 2005, 10(10), 1286-1291; doi:10.3390/10101286

Received: 12 December 2004 / Revised: 21 April 2005 / Accepted: 4 May 2005 / Published: 31 October 2005

Cited by 47 | Viewed by 5911 | PDF Full-text (62 KB) | HTML Full-text | XML Full-text

Abstract

The marine environment is a major source for many novel natural compounds. A new yellow pigment has been isolated from the marine bacterium P. tunicata and identified as a new member of the tambjamine class of compounds. The structural identification was achieved by

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The marine environment is a major source for many novel natural compounds. A new yellow pigment has been isolated from the marine bacterium P. tunicata and identified as a new member of the tambjamine class of compounds. The structural identification was achieved by a combination of 1D and 2D-NMR spectroscopy and high resolution mass spectrometry data. Full article

(This article belongs to the Special Issue 2004 RACI One-day Natural Products Group Symposium)

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Open AccessArticle Fragrance Release from the Surface of Branched Poly (Amide) S

by F. Aulenta, M. Drew, A. Foster, W. Hayes, S. Rannard, D. Thornthwaite and T. Youngs

Molecules 2005, 10(1), 81-97; doi:10.3390/10010081

Received: 14 May 2004 / Accepted: 29 June 2005 / Published: 31 January 2005

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Abstract

Enzymes are powerful tools in organic synthesis that are able to catalyse a wide variety of selective chemical transformations under mild and environmentally friendly conditions. Enzymes such as the lipases have also found applications in the synthesis and degradation of polymeric materials. However,

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Enzymes are powerful tools in organic synthesis that are able to catalyse a wide variety of selective chemical transformations under mild and environmentally friendly conditions. Enzymes such as the lipases have also found applications in the synthesis and degradation of polymeric materials. However, the use of these natural catalysts in the synthesis and the post-synthetic modification of dendrimers and hyperbranched molecules is an application of chemistry yet to be explored extensively. In this study the use of two hydrolytic enzymes, a lipase from Candida cylindracea and a cutinase from Fusarium solani pisii, were investigated in the selective cleavage of ester groups situated on the peripheral layer of two families of branched polyamides. These branched polyamides were conjugated to simple fragrances citronellol and L-menthol via ester linkages. Hydrolysis of the ester linkage between the fragrances and the branched polyamide support was carried out in aqueous buffered systems at slightly basic pH values under the optimum operative conditions for the enzymes used. These preliminary qualitative investigations revealed that partial cleavage of the ester functionalities from the branched polyamide support had occurred. However, the ability of the enzymes to interact with the substrates decreased considerably as the branching density, the rigidity of the structure and the bulkiness of the polyamide-fragrance conjugates increased. Full article

(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutical Chemistry)

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Open AccessArticle New Alkaloids from the Mediterranean Sponge Hamigera hamigera

by Wafaa Hassan, RuAngelie Edrada, Rainer Ebel, Victor Wray and Peter Proksch

Mar. Drugs 2004, 2(3), 88-100; doi:10.3390/md203088

Received: 30 April 2004 / Accepted: 27 May 2004 / Published: 25 August 2004

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Abstract

The Mediterranean sponge Hamigera hamigera (family Anchinoideae) was studied since its total extract showed deterrent activity in a fish feeding assay. Eight compounds were isolated from the biologically active fractions and four of these proved to be new natural products, hamigeroxalamic acid (1),

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The Mediterranean sponge Hamigera hamigera (family Anchinoideae) was studied since its total extract showed deterrent activity in a fish feeding assay. Eight compounds were isolated from the biologically active fractions and four of these proved to be new natural products, hamigeroxalamic acid (1), hamigeramine (2), hamigeramide (3) and hamiguanosinol (5). The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry . Full article

Open AccessArticle SELDI-TOF-MS Analysis of Transcriptional Activation Protein Binding to Response Elements Regulating Carcinogenesis Enzymes

by Steve R. Bischoff, Mahfuz B. Kahn, Michael D. Powell and Ward G. Kirlin

Int. J. Mol. Sci. 2002, 3(10), 1027-1038; doi:10.3390/i3101027

Received: 7 June 2002 / Accepted: 31 October 2002 / Published: 31 October 2002

Cited by 3 | Viewed by 6120 | PDF Full-text (201 KB) | HTML Full-text | XML Full-text

Abstract

The risk from chemical carcinogens and environmental toxins is dependent on the metabolic balance between bioactivation and detoxification enzymes. Therefore, agents that alter enzyme expression are critical factors in toxicity. Enhancement or suppression of enzyme activities through gene expression is in part regulated

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The risk from chemical carcinogens and environmental toxins is dependent on the metabolic balance between bioactivation and detoxification enzymes. Therefore, agents that alter enzyme expression are critical factors in toxicity. Enhancement or suppression of enzyme activities through gene expression is in part regulated by interactions between specific DNA promoter response elements and specific transcription proteins. DNA-protein interactions are dependent upon translocation of proteins from the cytoplasm to the nucleus and the affinity of proteins for binding to transcription promoter sequences. A key factor in both processes is the intracellular redox state, which influences protein-protein interactions and protein-DNA binding and can be altered by exposure to electrophiles, antioxidants and oxidative stress. Oxidative stress levels can be readily detected by measurable effects on the intracellular glutathione (GSH):glutathione disulfide redox potential, the major intracellularredox buffer. Alterations in the GSH redox pool can directly affect enzyme activity by altering disulfide bonds in the transcription factors regulating enzyme expression. These may affect: 1) specific DNA-protein and protein-protein interactions, 2) cyst(e)ine redox state within transcriptional proteins and 3) translocation of transcription proteins from cytoplasmic to nuclear compartments within the cell. The studies reported here are designed to investigate the relative changes in enzyme expression in response to cellular redox potential changes using the new proteomics technology of surface enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI). Treatment of HeLa and HT29 human cell lines to increase the expression of enzymes that are upregulated by oxidative stress was used as a model system to determine the efficacy of the SELDI technology in measuring changes in transcriptional protein binding to transcriptional response elements. An important goal is to determine whether the SELDI will allow simultaneous studies of multiple transcriptional protein-DNA interactions in response to controlled oxidative stress. This will provide a better understanding of the effect of electrophilic carcinogens and oxidants on the balance between activation and detoxification mechanisms in chemical carcinogenesis. Full article

(This article belongs to the Special Issue Recent Advances in Environmental Health Research: Health Disparities, Toxicology and Carcinogenesis. Part II)

Open AccessArticle Synthesis of Two Potentially Heptadentate (N4O3) Schiff-base Ligands Derived from Condensation of Tris(3-aminopropyl)-amine and Salicylaldehyde or 4-Hydroxysalicylaldehyde. Nickel(II) and Copper(II) Complexes of the Former Ligand

by Hassan Keypour, Sadegh Salehzadeh and R. V. Parish

Molecules 2002, 7(2), 140-144; doi:10.3390/70200140

Received: 9 December 2001 / Revised: 6 February 2002 / Accepted: 11 February 2002 / Published: 28 February 2002

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Abstract

Two potentially heptadentate (N4O3) tripodal Schiff-base ligands: tris(3-(salicylideneimino)propyl)amine (H₃L1) and tris(3-(4’-hydroxysalicylideneimino)-propyl)amine (H₃L2) have been prepared and characterized by various spectroscopic methods (IR, FAB-MS, NMR). They are derived from the condensation reactions of tris(3-aminopropyl)amine (tpt), with 3 equivalents of either

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Two potentially heptadentate (N4O3) tripodal Schiff-base ligands: tris(3-(salicylideneimino)propyl)amine (H₃L1) and tris(3-(4’-hydroxysalicylideneimino)-propyl)amine (H₃L2) have been prepared and characterized by various spectroscopic methods (IR, FAB-MS, NMR). They are derived from the condensation reactions of tris(3-aminopropyl)amine (tpt), with 3 equivalents of either salicylaldehyde or the ringsubstituted salicylaldehyde, 4-hydroxysalicylaldehyde. The nickel(II) and copper(II) complexes of H₃L1 were obtained from the its reactions Ni(II) and Cu(II) salts in absolute methanol. These complexes were studied by IR and FAB-Mass spectrometry. Full article

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Open AccessArticle Synthesis of Bis (2,2,6,6-tetramethyl-4-piperidinyl) Maleate

by Fu An Wang, Jiqin Zhu, Jianchi Song, Shengli Zhai and Lei Wang

Molecules 2001, 6(6), 528-532; doi:10.3390/60600528

Received: 22 August 2000 / Revised: 20 March 2001 / Accepted: 8 May 2001 / Published: 31 May 2001

Cited by 2 | Viewed by 5496 | PDF Full-text (47 KB) | HTML Full-text | XML Full-text

Abstract

Bis (2,2,6,6-tetramethyl-4-piperidinyl) maleate is a key intermediate for the synthesis of new types of hindered amine light stabilizers (HALS), so new synthetic routes to this compound are desirable. Through an orthogonal design and follow-up single factor experiments optimal reaction conditions were determined for

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Bis (2,2,6,6-tetramethyl-4-piperidinyl) maleate is a key intermediate for the synthesis of new types of hindered amine light stabilizers (HALS), so new synthetic routes to this compound are desirable. Through an orthogonal design and follow-up single factor experiments optimal reaction conditions were determined for synthesizing bis (2,2,6,6-tetramethyl-4-piperidiny) maleate using dimethyl maleate, 2,2,6,6-tetramethyl-4-piperidinol and zeolite supported tetraisopropyl titanate as catalyst. Under the selected conditions, the reaction rate and the yield are high, the selectivity is good, the catalyst can be recycled, and there are fewer wastes. The product was characterized and quantitatively analyzed by elemental analysis, mass spectrometry, infrared spectroscopy, nuclear magnetic resonance spectroscopy and ion suppression chromatography. Full article

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