Molecules

400 KiB

Open AccessArticle

Evaluation of the Antinociceptive Activity and Acute Oral Toxicity of Standardized Ethanolic Extract of the Rhizome of Curcuma xanthorrhiza Roxb

by Sutha Devaraj, Azadeh Sabetghadam Esfahani, Sabariah Ismail, Surash Ramanathan and Mun Fei Yam

Molecules 2010, 15(4), 2925-2934; https://doi.org/10.3390/molecules15042925 - 22 Apr 2010

Cited by 52 | Viewed by 13391

Abstract

Ethanolic extract of Curcuma xanthorrhiza was used to evaluate the analgesic and toxicity effects in vivo. The extract was standardized using GC-MS, which showed that 1 mg of Curcuma xanthorrhiza ethanolic extract contains 0.1238 mg of xanthorrhizol. The analgesic activity was studied [...] Read more.

Ethanolic extract of Curcuma xanthorrhiza was used to evaluate the analgesic and toxicity effects in vivo. The extract was standardized using GC-MS, which showed that 1 mg of Curcuma xanthorrhiza ethanolic extract contains 0.1238 mg of xanthorrhizol. The analgesic activity was studied in rats using three different models, namely the hot plate test, tail flick test and formalin-induced pain test. The acute oral toxicity was examined by the oral administration of standardized Curcuma xanthorrhiza ethanolic extract in mice at doses ranging from 300–5,000 mg/kg and observation for 14 days. Standardized Curcuma xanthorrhiza ethanolic extract did not show significant analgesic effect in the hot plate and tail flick tests. However, in the formalin-induced pain test, Curcuma xanthorrhiza ethanolic extract significantly (P < 0.05) suppressed the paw licking time of rats in both early and late phases at doses 200 and 400 mg/kg of the extract, respectively. In the acute oral toxicity study, Curcuma xanthorrhiza ethanolic extract did not show any toxic effects in mice at 5 g/kg. These experimental results suggest that the standardized Curcuma xanthorrhiza ethanolic extract showed peripheral and central antinociceptive activity associated with neurogenic pain as well as a relative absence of toxic effects which could compromise the medicinal use of this plant in folk medicine. Full article

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204 KiB

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; https://doi.org/10.3390/molecules15042911 - 22 Apr 2010

Cited by 42 | Viewed by 12050

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 [...] Read more.

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

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624 KiB

Open AccessArticle

Pharmacogenomic Identification of c-Myc/Max-Regulated Genes Associated with Cytotoxicity of Artesunate towards Human Colon, Ovarian and Lung Cancer Cell Lines

by Serkan Sertel, Tolga Eichhorn, Christian H. Simon, Peter K. Plinkert, Steven W. Johnson and Thomas Efferth

Molecules 2010, 15(4), 2886-2910; https://doi.org/10.3390/molecules15042886 - 22 Apr 2010

Cited by 44 | Viewed by 15647

Abstract

Development of novel therapy strategies is one of the major pressing topics of clinical oncology to overcome drug resistance of tumors. Artesunate (ART) is an anti-malarial drug, which also exerts profound cytotoxic activity towards cancer cells. We applied a gene-hunting approach using microarray-based [...] Read more.

Development of novel therapy strategies is one of the major pressing topics of clinical oncology to overcome drug resistance of tumors. Artesunate (ART) is an anti-malarial drug, which also exerts profound cytotoxic activity towards cancer cells. We applied a gene-hunting approach using microarray-based transcriptome-wide mRNA expression profiling and COMPARE analyses. We identified a set of genes, whose expression was associated either with high IC₅₀ values or low IC₅₀ values for ART. Therefore, these genes may function as resistance or sensitivity factors for response of tumor cells towards ART. This viewpoint is conceivable for genes involved in ribosomal activity, drug transport, cellular antioxidant defense, apoptosis, cell proliferation, cell cycle progression etc. An investigation of underlying signal transduction by pathway analysis suggested a role of the signaling pathways related to tumor necrosis factor (TNF) and the tumor suppressor p53. On the other hand, there were genes without obvious functional link to cellular response to ART, such as genes involved in the survival of cochlear outer and inner hair cells etc. We proved the hypothesis that ART influences the activity of transcription factors regulating downstream genes involved or not involved in response of cancer cells towards ART. This would explain the identification of genes with and without obvious relation to the cytotoxic activity of ART by microarray and COMPARE analyses. By analysis of the binding motifs for the transcription factors c-Myc and Max, we indeed found that 53 of 56 genes contained one or more binding sites for c-Myc/Max upstream of the gene-location. We conclude that c-Myc and Max-mediated transcriptional control of gene expression might contribute to the therapeutic effects of ART in cancer cells, but may also confer unwanted side effects by affecting therapy-unrelated genes. Full article

(This article belongs to the Special Issue Artemisinin (Qinghaosu): Commemorative Issue in Honor of Professor Youyou Tu on the Occasion of her 80th Anniversary)

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712 KiB

Open AccessArticle

Preparation, Characterization and Adsorption Performance of a Novel Anionic Starch Microsphere

by Yati Yang, Xiuzhi Wei, Peng Sun and Juanmin Wan

Molecules 2010, 15(4), 2872-2885; https://doi.org/10.3390/molecules15042872 - 21 Apr 2010

Cited by 45 | Viewed by 10410

Abstract

Neutral starch microspheres (NSMs) were synthesized by an inverse microemulsion technology with epichlorohydrin as a crosslinker and soluble starch as starting material. Anionic starch microspheres (ASMs) were prepared from NSMs by the secondary polymerization with chloroacetic acid as the anionic etherifying agent. Fourier [...] Read more.

Neutral starch microspheres (NSMs) were synthesized by an inverse microemulsion technology with epichlorohydrin as a crosslinker and soluble starch as starting material. Anionic starch microspheres (ASMs) were prepared from NSMs by the secondary polymerization with chloroacetic acid as the anionic etherifying agent. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and laser diffraction particle size analyzer were used to characterize the anionic starch microspheres. The results showed that structure of the microspheres was compact and the hardness of microspheres was great, and the average diameter of the product was about 75 µm. The anionic starch microspheres (ASMs) were used to adsorb methylene blue (MB) from aqueous solution. Effects of adsorption time, initial concentration of MB, and temperature on the adsorption of MB onto ASMs were studied, and the equilibrium and kinetics of the adsorption process were further investigated. It shows that ASMs can effectively remove MB from the solution. The adsorption equilibrium data correlates well with the Langmuir isotherm model compared with Frendlich isotherem model. The pseudo-first-order and pseudo-second-order kinetic models were applied to test the experimental data. The pseudo-second-order kinetic model provided a better correlation of the experimental data in comparison with the pseudo-first-order model. Temperature variations did not significantly affect the adsorption of MB onto ASMs. Full article

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419 KiB

Open AccessArticle

Conversion of Aryl Iodides into Aryliodine(III) Dichlorides by an Oxidative Halogenation Strategy Using 30% Aqueous Hydrogen Peroxide in Fluorinated Alcohol

by Ajda Podgoršek and Jernej Iskra

Molecules 2010, 15(4), 2857-2871; https://doi.org/10.3390/molecules15042857 - 20 Apr 2010

Cited by 22 | Viewed by 12821

Abstract

Oxidative chlorination with HCl/H₂O₂ in 1,1,1-trifluoroethanol was used to transform aryl iodides into aryliodine(III) dihalides. In this instance 1,1,1-trifluoroethanol is not only the reaction medium, but is also an activator of hydrogen peroxide for the oxidation of hydrochloric acid to [...] Read more.

Oxidative chlorination with HCl/H₂O₂ in 1,1,1-trifluoroethanol was used to transform aryl iodides into aryliodine(III) dihalides. In this instance 1,1,1-trifluoroethanol is not only the reaction medium, but is also an activator of hydrogen peroxide for the oxidation of hydrochloric acid to molecular chlorine. Aryliodine(III) dichlorides were formed in 72–91% isolated yields in the reaction of aryl iodides with 30% aqueous hydrogen peroxide and hydrochloric acid at ambient temperature. A study of the effect that substituents on the aromatic ring have on the formation and stability of aryliodine(III) dichlorides shows that the transformation is easier to achieve in the presence of the electron-donating groups (i.e. methoxy), but in this case the products rapidly decompose under the reported reaction conditions to form chlorinated arenes. The results suggest that oxidation of hydrogen chloride with hydrogen peroxide is the initial reaction step, while direct oxidation of aryl iodide with hydrogen peroxide is less likely to occur. Full article

(This article belongs to the Special Issue Organic Iodine Chemistry)

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2432 KiB

Open AccessArticle

Cell Proliferation of HaCaT Keratinocytes on Collagen Films Modified by Argon Plasma Treatment

by Jorge López García, Ahmad Asadinezhad, Jiří Pacherník, Marián Lehocký, Ita Junkar, Petr Humpolíček, Petr Sáha and Pavel Valášek

Molecules 2010, 15(4), 2845-2856; https://doi.org/10.3390/molecules15042845 - 20 Apr 2010

Cited by 70 | Viewed by 13920

Abstract

Argon plasma treatment was used to modify the surface of atelocollagen films using a plasmochemical reactor. To evaluate the effects of the treatment, the untreated and treated samples were characterized by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM) [...] Read more.

Argon plasma treatment was used to modify the surface of atelocollagen films using a plasmochemical reactor. To evaluate the effects of the treatment, the untreated and treated samples were characterized by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM) imaging, and X-ray Photoelectron Spectroscopy (XPS) techniques. Cell growth was carried out by culturing human immortalized keratinocyte (HaCaT) cells and proliferation was measured via MTT assay. It was observed that argon plasma treatment significantly enhanced the extent of cell proliferation, which was ascribed to the favourable role of plasma treatment in inducing surface oxygen-containing entities together with increasing surface roughness. This can be considered as a potentially promising approach for tissue regeneration purposes. Full article

(This article belongs to the Special Issue Solid Phase Synthesis)

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Open AccessReview

µ-Conotoxins as Leads in the Development of New Analgesics

by Raymond S. Norton

Molecules 2010, 15(4), 2825-2844; https://doi.org/10.3390/molecules15042825 - 19 Apr 2010

Cited by 48 | Viewed by 25200

Abstract

Voltage-gated sodium channels (VGSCs) contain a specific binding site for a family of cone shell toxins known as µ-conotoxins. As some VGSCs are involved in pain perception and µ-conotoxins are able to block these channels, µ-conotoxins show considerable potential as analgesics. Recent studies [...] Read more.

Voltage-gated sodium channels (VGSCs) contain a specific binding site for a family of cone shell toxins known as µ-conotoxins. As some VGSCs are involved in pain perception and µ-conotoxins are able to block these channels, µ-conotoxins show considerable potential as analgesics. Recent studies have advanced our understanding of the three-dimensional structures and structure-function relationships of the µ-conotoxins, including their interaction with VGSCs. Truncated peptide analogues of the native toxins have been created in which secondary structure elements are stabilized by non-native linkers such as lactam bridges. Ultimately, it would be desirable to capture the favourable analgesic properties of the native toxins, in particular their potency and channel sub-type selectivity, in non-peptide mimetics. Such mimetics would constitute lead compounds in the development of new therapeutics for the treatment of pain. Full article

(This article belongs to the Special Issue Toxins - Organic and Analytical Chemistry)

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1371 KiB

Open AccessArticle

Neuroprotective Effects of Herbal Ethanol Extracts from Gynostemma pentaphyllum in the 6-Hydroxydopamine-Lesioned Rat Model of Parkinson's Disease

by Hyun Sook Choi, Mi Sook Park, Seung Hwan Kim, Bang Yeon Hwang, Chong Kil Lee and Myung Koo Lee

Molecules 2010, 15(4), 2814-2824; https://doi.org/10.3390/molecules15042814 - 16 Apr 2010

Cited by 58 | Viewed by 18523

Abstract

6-Hydroxydopamine administration for 28 days (8 μg/2 μL) reduced the number of tyrosine hydroxylase (TH)-immunopositive neurons to 40.2% in the substantia nigra compared to the intact contralateral side. Dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid and norepinephrine levels were reduced to 19.1%, 52.3%, 47.1% and [...] Read more.

6-Hydroxydopamine administration for 28 days (8 μg/2 μL) reduced the number of tyrosine hydroxylase (TH)-immunopositive neurons to 40.2% in the substantia nigra compared to the intact contralateral side. Dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid and norepinephrine levels were reduced to 19.1%, 52.3%, 47.1% and 67.4% in the striatum of 6-hydroxydopamine-lesioned rats compared to the control group, respectively. However, an oral administration of herbal ethanol extracts from Gynostemma pentaphyllum (GP-EX) (10 mg/kg and 30 mg/kg) starting on day 3 post-lesion for 28 days markedly ameliorated the reduction of TH-immunopositive neurons induced by 6-hydroxydopamine-lesioned rat brain from 40.2% to 67.4% and 75.8% in the substantia nigra. GP-EX administration (10 and 30 mg/kg) also recovered the levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid and norepinephrine in post-lesion striatum to 64.1% and 65.0%, 77.9% and 89.7%, 82.6% and 90.2%, and 88.1% and 89.2% of the control group. GP-EX at the given doses did not produce any sign of toxicity such as weight loss, diarrhea and vomiting in rats during the 28 day treatment period and four gypenoside derivatives, gynosaponin TN-1, gynosaponin TN-2, gypenoside XLV and gypenoside LXXIV were identified from GP-EX. These results suggest that GP-EX might be helpful in the prevention of Parkinson’s disease. Full article

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Open AccessArticle

Elucidating Drug-Enzyme Interactions and Their Structural Basis for Improving the Affinity and Potency of Isoniazid and Its Derivatives Based on Computer Modeling Approaches

by Auradee Punkvang, Patchreenart Saparpakorn, Supa Hannongbua, Peter Wolschann and Pornpan Pungpo

Molecules 2010, 15(4), 2791-2813; https://doi.org/10.3390/molecules15042791 - 16 Apr 2010

Cited by 12 | Viewed by 10655

Abstract

The enoyl-ACP reductase enzyme (InhA) from M. tuberculosis is recognized as the primary target of isoniazid (INH), a first-line antibiotic for tuberculosis treatment. To identify the specific interactions of INH-NAD adduct and its derivative adducts in InhA binding pocket, molecular docking calculations and [...] Read more.

The enoyl-ACP reductase enzyme (InhA) from M. tuberculosis is recognized as the primary target of isoniazid (INH), a first-line antibiotic for tuberculosis treatment. To identify the specific interactions of INH-NAD adduct and its derivative adducts in InhA binding pocket, molecular docking calculations and quantum chemical calculations were performed on a set of INH derivative adducts. Reliable binding modes of INH derivative adducts in the InhA pocket were established using the Autodock 3.05 program, which shows a good ability to reproduce the X-ray bound conformation with rmsd of less than 1.0 Å. The interaction energies of the INH-NAD adduct and its derivative adducts with individual amino acids in the InhA binding pocket were computed based on quantum chemical calculations at the MP2/6-31G (d) level. The molecular docking and quantum chemical calculation results reveal that hydrogen bond interactions are the main interactions for adduct binding. To clearly delineate the linear relationship between structure and activity of these adducts, CoMFA and CoMSIA models were set up based on molecular docking alignment. The resulting CoMFA and CoMSIA models are in conformity with the best statistical qualities, in which r²_cv is 0.67 and 0.74, respectively. Structural requirements of isoniazid derivatives that can be incorporated into the isoniazid framework to improve the activity have been identified through CoMFA and CoMSIA steric and electrostatic contour maps. The integrated results from structure-based, ligand-based design approaches and quantum chemical calculations provide useful structural information facilitating the design of new and more potentially effective antitubercular agents as follow: the R substituents of isoniazid derivatives should contain a large plane and both sides of the plane should contain an electropositive group. Moreover, the steric and electrostatic fields of the 4-pyridyl ring are optimal for greater potency. Full article

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234 KiB

Open AccessArticle

p-Aminoacetophenonic Acids Produced by a Mangrove Endophyte Streptomyces sp. (strain HK10552)

by Fangfang Wang, Minjuan Xu, Qingshan Li, Isable Sattler and Wenhan Lin

Molecules 2010, 15(4), 2782-2790; https://doi.org/10.3390/molecules15042782 - 16 Apr 2010

Cited by 34 | Viewed by 9596

Abstract

Four new p-aminoacetophenonic acids, named (2E)-11-(4′-aminophenyl)-5,9-dihydroxy-4,6,8-trimethyl-11-oxo-undec-2-enoic acid (1), 9-(4′-aminophenyl)-3,7-dihydroxy-2,4,6-trimethyl-9-oxo-nonoic acid(2), (2E)-11-(4′-aminophenyl)-5,9-O-cyclo-4,6,8-trimethyl-11-oxo-undec-2-enoic acid (3) and 9-(4′-aminophenyl)-3,7-O-cyclo-2,4,6-trimethyl-9-oxo-nonoic acid(4), were isolated from an endophyte Streptomyces sp. (strain HK10552) of [...] Read more.

Four new p-aminoacetophenonic acids, named (2E)-11-(4′-aminophenyl)-5,9-dihydroxy-4,6,8-trimethyl-11-oxo-undec-2-enoic acid (1), 9-(4′-aminophenyl)-3,7-dihydroxy-2,4,6-trimethyl-9-oxo-nonoic acid(2), (2E)-11-(4′-aminophenyl)-5,9-O-cyclo-4,6,8-trimethyl-11-oxo-undec-2-enoic acid (3) and 9-(4′-aminophenyl)-3,7-O-cyclo-2,4,6-trimethyl-9-oxo-nonoic acid(4), were isolated from an endophyte Streptomyces sp. (strain HK10552) of the mangrove plant Aegiceras corniculatum. The structures of 1–4 were elucidated by using spectroscopic analyses. The relative stereoconfigurations of compounds 3 and 4 were determined by NOESY experiments. In the bioassay test, 1–4 showed no cytotoxicity against the Hela cell lines. Compound 4 also showed no inhibitory bioactivity on HCV protease and SecA ATPase and wasn’t active against VSVG/HIV-luc pseudotyping virus. Full article

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194 KiB

Open AccessArticle

A General and Simple Diastereoselective Reduction by L-Selectride: Efficient Synthesis of Protected (4S,5S)-Dihydroxy Amides

by Bo Yin, Dong-Nai Ye, Kai-Hui Yu and Liang-Xian Liu

Molecules 2010, 15(4), 2771-2781; https://doi.org/10.3390/molecules15042771 - 16 Apr 2010

Cited by 2 | Viewed by 10975

Abstract

A general approach to (4S,5S)-4-benzyloxy-5-hydroxy-N-(4-methoxybenzyl) amides 10 based on a diastereoselective reduction of (5S,6RS)-6-alkyl-5-benzyloxy-6-hydroxy-2-piperidinones 6 and their tautomeric ring-opened keto amides 7 is described. The reduction with L-Selectride at -20 °C to [...] Read more.

A general approach to (4S,5S)-4-benzyloxy-5-hydroxy-N-(4-methoxybenzyl) amides 10 based on a diastereoselective reduction of (5S,6RS)-6-alkyl-5-benzyloxy-6-hydroxy-2-piperidinones 6 and their tautomeric ring-opened keto amides 7 is described. The reduction with L-Selectride at -20 °C to room temperature afforded the products 10 in excellent yields and moderate to high syn-diastereoselectivities. Full article

(This article belongs to the Special Issue Asymmetric Synthesis)

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Open AccessReview

Essential Oil of Myrtus communis L. as a Potential Antioxidant and Antimutagenic Agents

by Neda Mimica-Dukić, Dušan Bugarin, Slavenko Grbović, Dragana Mitić-Ćulafić, Branka Vuković-Gačić, Dejan Orčić, Emilija Jovin and Maria Couladis

Molecules 2010, 15(4), 2759-2770; https://doi.org/10.3390/molecules15042759 - 15 Apr 2010

Cited by 159 | Viewed by 14717

Abstract

The present study describes DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and antimutagenic properties of the essential oil of myrtle (Myrtus communis L.). Plant samples were collected from the two distant localities (southernmost and northern point) of the Montenegro coastline. Chemical profiles of the [...] Read more.

The present study describes DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and antimutagenic properties of the essential oil of myrtle (Myrtus communis L.). Plant samples were collected from the two distant localities (southernmost and northern point) of the Montenegro coastline. Chemical profiles of the two samples were evaluated by GC-MS. In both of the samples monoterpenes were found to be the predominant compounds. Among them a-pinene, linalool, 1,8-cineole, and myrtenyl acetate were the major compounds. Significant differences between the samples were found in the ranges of a-pinene (14.7%–35.9%) and myrtenyl acetate (5.4%–21.6%). Both oils exhibited moderate DPPH scavenging activity, with IC₅₀ values of 6.24 mg/mL and 5.99 mg/mL. The antimutagenic properties were assayed against spontaneous and t-BOOH-induced mutagenesis in Escherichia coli oxyR mutant IC202, a bacterial strain deficient in removing ROS. Reduction of the spontaneous mutagenesis in presence of myrtle EO was only slight, up to 13% at the highest concentration tested. When the oxidative mutagen was used, EO expressed higher reduction of mutagenesis, in a concentration dependent manner, with statistical significance for effect at the highest concentration tested (28%). Suppression of t-BOOH induced mutagenesis was correlated with the observed scavenging activity. Full article

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Open AccessArticle

Reactivity Ratios for Organotin Copolymer Systems

by Mohamed H. El-Newehy, Salem S. Al-Deyab and Ali Mohsen Ali Al-Hazmi

Molecules 2010, 15(4), 2749-2758; https://doi.org/10.3390/molecules15042749 - 15 Apr 2010

Cited by 12 | Viewed by 11067

Abstract

Di(tri-n-butyltin) itaconate (DTBTI) and monoethyl tributyltin fumarate (METBTF) were synthesized as organotin monomers. The organotin monomers were copolymerized with styrene (ST) and methyl methacrylate (MMA) via a free radical polymerization technique. The overall conversion was kept low (£15% wt/wt) for all [...] Read more.

Di(tri-n-butyltin) itaconate (DTBTI) and monoethyl tributyltin fumarate (METBTF) were synthesized as organotin monomers. The organotin monomers were copolymerized with styrene (ST) and methyl methacrylate (MMA) via a free radical polymerization technique. The overall conversion was kept low (£15% wt/wt) for all studied samples and the copolymer composition was determined from tin analysis. The synthesized monomers and copolymers were characterized by elemental analysis, ¹H- and ¹³C-NMR, and FTIR spectroscopy. Full article

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901 KiB

Open AccessArticle

MMPBSA Decomposition of the Binding Energy throughout a Molecular Dynamics Simulation of Amyloid-Beta (Aß₁₀₋₃₅) Aggregation

by Josep M. Campanera and Ramon Pouplana

Molecules 2010, 15(4), 2730-2748; https://doi.org/10.3390/molecules15042730 - 15 Apr 2010

Cited by 35 | Viewed by 14709

Abstract

Recent experiments with amyloid-beta (Aβ) peptides indicate that the formation of toxic oligomers may be an important contribution to the onset of Alzheimer’s disease. The toxicity of Aβ oligomers depend on their structure, which is governed by assembly dynamics. However, a detailed knowledge [...] Read more.

Recent experiments with amyloid-beta (Aβ) peptides indicate that the formation of toxic oligomers may be an important contribution to the onset of Alzheimer’s disease. The toxicity of Aβ oligomers depend on their structure, which is governed by assembly dynamics. However, a detailed knowledge of the structure of at the atomic level has not been achieved yet due to limitations of current experimental techniques. In this study, replica exchange molecular dynamics simulations are used to identify the expected diversity of dimer conformations of Aβ₁₀₋₃₅ monomers. The most representative dimer conformation has been used to track the dimer formation process between both monomers. The process has been characterized by means of the evolution of the decomposition of the binding free energy, which provides an energetic profile of the interaction. Dimers undergo a process of reorganization driven basically by inter-chain hydrophobic and hydrophilic interactions and also solvation/desolvation processes. Full article

(This article belongs to the Special Issue Combinatorial Chemistry)

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Open AccessArticle

Access to Original Vinylic Chlorides in the Quinazoline Series via a Monoelectronic Transfer Reaction Approach

by Martine Maillard-Boyer, Caroline Castera-Ducros, Pierre Verhaeghe, France Sifredi, Pascal Rathelot and Patrice Vanelle

Molecules 2010, 15(4), 2719-2729; https://doi.org/10.3390/molecules15042719 - 13 Apr 2010

Cited by 4 | Viewed by 6420

Abstract

A series of new quinazoline derivatives bearing a vinylic chloride group on the 2-position was prepared by using a consecutive S_RN1 / E_RC1 radical strategy. Full article

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779 KiB

Open AccessReview

Iodine-124: A Promising Positron Emitter for Organic PET Chemistry

by Lena Koehler, Katherine Gagnon, Steve McQuarrie and Frank Wuest

Molecules 2010, 15(4), 2686-2718; https://doi.org/10.3390/molecules15042686 - 13 Apr 2010

Cited by 94 | Viewed by 15947

Abstract

The use of radiopharmaceuticals for molecular imaging of biochemical and physiological processes in vivo has evolved into an important diagnostic tool in modern nuclear medicine and medical research. Positron emission tomography (PET) is currently the most sophisticated molecular imaging methodology, mainly due to [...] Read more.

The use of radiopharmaceuticals for molecular imaging of biochemical and physiological processes in vivo has evolved into an important diagnostic tool in modern nuclear medicine and medical research. Positron emission tomography (PET) is currently the most sophisticated molecular imaging methodology, mainly due to the unrivalled high sensitivity which allows for the studying of biochemistry in vivo on the molecular level. The most frequently used radionuclides for PET have relatively short half-lives (e.g. ¹¹C: 20.4 min; ¹⁸F: 109.8 min) which may limit both the synthesis procedures and the time frame of PET studies. Iodine-124 (¹²⁴I, t_1/2= 4.2 d) is an alternative long-lived PET radionuclide attracting increasing interest for long term clinical and small animal PET studies. The present review gives a survey on the use of ¹²⁴I as promising PET radionuclide for molecular imaging. The first part describes the production of ¹²⁴I. The second part covers basic radiochemistry with ¹²⁴I focused on the synthesis of ¹²⁴I-labeled compounds for molecular imaging purposes. The review concludes with a summary and an outlook on the future prospective of using the long-lived positron emitter ¹²⁴I in the field of organic PET chemistry and molecular imaging. Full article

(This article belongs to the Special Issue Organic Iodine Chemistry)

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Open AccessReview

The Heck Reaction Applied to 1,3- and 1,2-Unsaturated Derivatives, a Way towards Molecular Complexity

by Annamaria Deagostino, Cristina Prandi, Silvia Tabasso and Paolo Venturello

Molecules 2010, 15(4), 2667-2685; https://doi.org/10.3390/molecules15042667 - 13 Apr 2010

Cited by 56 | Viewed by 13408

Abstract

This review is an overview of the last ten years’ use of the Mizoroki–Heck coupling applied to 1,2- and 1,3-dienes. Since both these systems form π-allyl palladium intermediates in Pd(0) coupling, they show particular chemical behavior. Many examples of 1,2-dienes Heck reactions are [...] Read more.

This review is an overview of the last ten years’ use of the Mizoroki–Heck coupling applied to 1,2- and 1,3-dienes. Since both these systems form π-allyl palladium intermediates in Pd(0) coupling, they show particular chemical behavior. Many examples of 1,2-dienes Heck reactions are presented. 1,2-Dienes are important substrates because of their high reactivity that makes them useful building blocks for the synthesis of biologically relevant structures. Full article

(This article belongs to the Special Issue Heck Coupling)

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Open AccessArticle

Pyridine-Based Heterocycles. Synthesis of New Pyrido [4',3':4,5]thieno[2,3-d]pyrimidines and Related Heterocycles

by Hussein El-Kashef, Abdel-Rahman Farghaly, Ahmed Al-Hazmi, Thierry Terme and Patrice Vanelle

Molecules 2010, 15(4), 2651-2666; https://doi.org/10.3390/molecules15042651 - 12 Apr 2010

Cited by 18 | Viewed by 11268

Abstract

The synthesis of the title compounds was achieved using ethyl 2-amino-6-methyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate (1) as starting material. The reaction of the amino ester 1 with phenylisothiocyanate in boiling ethanol afforded the thiourea derivative 5. The cyclization reactions of 5 under [...] Read more.

The synthesis of the title compounds was achieved using ethyl 2-amino-6-methyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate (1) as starting material. The reaction of the amino ester 1 with phenylisothiocyanate in boiling ethanol afforded the thiourea derivative 5. The cyclization reactions of 5 under different reaction conditions led to different pyridothienopyrimidine derivatives. Other reactions of the latter derivatives leading to pyrido[4',3':4,5]thieno[2,3-d]triazolo[1,5-a]pyrimidines are also presented. Full article

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Open AccessArticle

New Chiral Phosphoramidite Complexes of Iron as Catalytic Precursors in the Oxidation of Activated Methylene Groups

by Pushkar Shejwalkar, Nigam P. Rath and Eike B. Bauer

Molecules 2010, 15(4), 2631-2650; https://doi.org/10.3390/molecules15042631 - 12 Apr 2010

Cited by 14 | Viewed by 9315

Abstract

New phosphoramidite complexes of iron were synthesized and structurally characterized. Reaction of the known chiral phosphoramidites (RO)₂PNR’₂ (R = binaphthyl, R’ = CH₃, 1a; R = binaphthyl, R’ = benzyl, 1b) with [FeBr(Cp)(CO)₂] afforded [...] Read more.

New phosphoramidite complexes of iron were synthesized and structurally characterized. Reaction of the known chiral phosphoramidites (RO)₂PNR’₂ (R = binaphthyl, R’ = CH₃, 1a; R = binaphthyl, R’ = benzyl, 1b) with [FeBr(Cp)(CO)₂] afforded the title compounds [FeBr(Cp)(CO)(1a,b)] (4a,b) in 34 and 65 % isolated yields as mixtures of diastereomers, since both the metal and the ligand are stereogenic. Similarly, reaction of 1b with [Fe(Cp)I(CO)₂] in the presence of catalytic [Fe(Cp)(CO)₂]₂ afforded [Fe(Cp)I(CO)(1b)] (5b) in 81% yield as a mixture of diastereomers. The molecular structures of 4a, 4b and 5 were determined, revealing a pseudo octahedral coordination geometry about the iron center. The new metal complexes are catalytically active in the oxidation of benzylic methylene groups to the corresponding ketones, utilizing t-BuOOH as oxidant (2 mol% catalyst, 36 h, room temperature, 31−80% yield). Full article

(This article belongs to the Special Issue Organometallic Chemistry)

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Open AccessArticle

Influence of Solvent, Electron Acceptors and Arenes on Photochemical Decarboxylation of Free Carboxylic Acids via Single Electron Transfer (SET)

by Yasuharu Yoshimi, Shota Hayashi, Keisuke Nishikawa, Yoshiki Haga, Kousuke Maeda, Toshio Morita, Tatsuya Itou, Yutaka Okada, Nobuyuki Ichinose and Minoru Hatanaka

Molecules 2010, 15(4), 2623-2630; https://doi.org/10.3390/molecules15042623 - 12 Apr 2010

Cited by 37 | Viewed by 9423

Abstract

Single electron transfer (SET)-photochemical decarboxylation of free carboxylic acids was performed in a polar solvent using several arenes such as phenanthrene, naphthalene, 1-methylnaphthalene, biphenyl, triphenylene, and chrysene in the presence of various electron acceptors such as 1,2-, 1,3-, and 1,4-dicyanobenzenes, methyl 4-cyanobenzoate, and [...] Read more.

Single electron transfer (SET)-photochemical decarboxylation of free carboxylic acids was performed in a polar solvent using several arenes such as phenanthrene, naphthalene, 1-methylnaphthalene, biphenyl, triphenylene, and chrysene in the presence of various electron acceptors such as 1,2-, 1,3-, and 1,4-dicyanobenzenes, methyl 4-cyanobenzoate, and 1,4-dicyanonaphthalene. The decarboxylation reaction was influenced by the arenes, electron acceptors, and solvent. The best result was achieved by the photoreaction using biphenyl and 1,4-dicyanonaphthalene in aqueous acetonitrile. Full article

(This article belongs to the Special Issue Photochemistry in Organic Synthesis)

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Open AccessArticle

High-Throughput Behavioral Screens: the First Step towards Finding Genes Involved in Vertebrate Brain Function Using Zebrafish

by Robert Gerlai

Molecules 2010, 15(4), 2609-2622; https://doi.org/10.3390/molecules15042609 - 12 Apr 2010

Cited by 175 | Viewed by 13774

Abstract

The zebrafish has been in the forefront of developmental biology for three decades and has become a favorite of geneticists. Due to the accumulated genetic knowledge and tools developed for the zebrafish it is gaining popularity in other disciplines, including neuroscience. The zebrafish [...] Read more.

The zebrafish has been in the forefront of developmental biology for three decades and has become a favorite of geneticists. Due to the accumulated genetic knowledge and tools developed for the zebrafish it is gaining popularity in other disciplines, including neuroscience. The zebrafish offers a compromise between system complexity (it is a vertebrate similar in many ways to our own species) and practical simplicity (it is small, easy to keep, and prolific). Such features make zebrafish an excellent choice for high throughput mutation and drug screening. For the identification of mutation or drug induced alteration of brain function arguably the best methods are behavioral test paradigms. This review does not present experimental examples for the identification of particular genes or drugs. Instead it describes how behavioral screening methods may enable one to find functional alterations in the vertebrate brain. Furthermore, the review is not comprehensive. The behavioral test examples presented are biased according to the personal interests of the author. They will cover research areas including learning and memory, fear and anxiety, and social behavior. Nevertheless, the general principles will apply to other functional domains and should represent a snapshot of the rapidly evolving behavioral screening field with zebrafish. Full article

(This article belongs to the Special Issue High-throughput Screening)

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Open AccessArticle

Chemical Composition and Insecticidal Activity against Sitophilus zeamais of the Essential Oils of Artemisia capillaris and Artemisia mongolica

by Zhi Long Liu, Sha Sha Chu and Quan Ru Liu

Molecules 2010, 15(4), 2600-2608; https://doi.org/10.3390/molecules15042600 - 12 Apr 2010

Cited by 75 | Viewed by 11470

Abstract

In our screening program for new agrochemicals from local wild plants, Artemisia capillaris and A. mongolica were found to possess insecticidal activity against the maize weevil, Sitophilus zeamais. The essential oils of aerial parts of the two plants were obtained [...] Read more.

In our screening program for new agrochemicals from local wild plants, Artemisia capillaris and A. mongolica were found to possess insecticidal activity against the maize weevil, Sitophilus zeamais. The essential oils of aerial parts of the two plants were obtained by hydrodistillation and were investigated by GC and GC-MS. The main components of A. capillaris essential oil were 1,8-cineole (13.75%), germacrene D (10.41%), and camphor (8.57%). The main constituents of A. mongolica essential oil were α-pinene (12.68%), germacrene D (8.36%), and γ-terpinene (8.17%). Essential oils of A. capillaris and A. mongolica possess fumigant toxicity against S. zeamais adults with LC₅₀ values of 5.31 and 7.35 mg/L respectively. The essential oils also show contact toxicity against S. zeamais adults with LD₅₀ values of 105.95 and 87.92 mg/adult, respectively. Full article

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Open AccessArticle

A New Sulfated α-Ionone Glycoside from Sonchus erzincanicus Matthews

by Ufuk Ozgen, Handan Sevindik, Cavit Kazaz, Demet Yigit, Ali Kandemir, Hasan Secen and Ihsan Calis

Molecules 2010, 15(4), 2593-2599; https://doi.org/10.3390/molecules15042593 - 12 Apr 2010

Cited by 31 | Viewed by 11623

Abstract

Sonchus erzincanicus (Asteraceae) is an endemic species in Turkey, where six Sonchus species grow. In this study, a phytochemical study was performed on the aerial parts of the plant. The study describes the isolation and structure elucidation of five flavonoids and two [...] Read more.

Sonchus erzincanicus (Asteraceae) is an endemic species in Turkey, where six Sonchus species grow. In this study, a phytochemical study was performed on the aerial parts of the plant. The study describes the isolation and structure elucidation of five flavonoids and two a-ionone glycosides from S. erzincanicus. The compounds were isolated using several and repeated chromatographic techniques from ethyl acetate and aqueous phases that were partitioned from a methanol extract obtained from the plant. 5,7,3',4'-Tetrahydroxy-3-methoxyflavone (1) and quercetin 3-O-β-D-glucoside (2) were isolated from the ethyl acetate phase, while corchoionoside C 6’-O-sulfate (3), corchoionoside C (4), luteolin 7-O-glucuronide (5) and luteolin 7-O-β-D-glucoside (6), apigenin 7-O-glucuronide (7) were isolated from the aqueous phase. Corchoionoside C 6’-O-sulfate (3), isolated for the first time from a natural source, was a new compound. The structures of the compounds were elucidated by means of ¹H-NMR, ¹³C-NMR, 2D-NMR (COSY, HMQC, HMBC) and ESI-MS. Full article

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Open AccessArticle

Antioxidant Capacity of Macaronesian Traditional Medicinal Plants

by Lucélia Tavares, Dina Carrilho, Meenu Tyagi, David Barata, Ana Teresa Serra, Catarina Maria Martins Duarte, Rui Oliveira Duarte, Rodrigo Pedro Feliciano, Maria Rosário Bronze, Paula Chicau, Maria Dalila Espírito-Santo, Ricardo Boavida Ferreira and Cláudia Nunes Dos Santos

Molecules 2010, 15(4), 2576-2592; https://doi.org/10.3390/molecules15042576 - 12 Apr 2010

Cited by 48 | Viewed by 17801

Abstract

The use of many traditional medicinal plants is often hampered by the absence of a proper biochemical characterization, essential to identify the bioactive compounds present. The leaves from five species endemic to the Macaronesian islands with recognized ethnobotanical applications were analysed: Apollonias barbujana [...] Read more.

The use of many traditional medicinal plants is often hampered by the absence of a proper biochemical characterization, essential to identify the bioactive compounds present. The leaves from five species endemic to the Macaronesian islands with recognized ethnobotanical applications were analysed: Apollonias barbujana (Cav.) Bornm., Ocotea foetens (Ainton) Baill, Prunus azorica (Mouill.) Rivas-Mart., Lousã, Fern. Prieto, E. Días, J.C. Costa & C. Aguiar, Rumex maderensis Lowe and Plantago arborescens Poir. subsp. maderensis (Dcne.) A. Hans. et Kunk.. Since oxidative stress is a common feature of most diseases traditionally treated by these plants, it is important to assess their antioxidant capacity and determine the molecules responsible for this capacity. In this study, the antioxidant capacity of these plants against two of the most important reactive species in human body (hydroxyl and peroxyl radicals) was determined. To trace the antioxidant origin total phenol and flavonoid contents as well as the polyphenolic profile and the amount of trace elements were determined. There was a wide variation among the species analysed in what concerns their total leaf phenol and flavonoid contents. From the High Performance Liquid Chromatography (HPLC) electrochemically detected peaks it was possible to attribute to flavonoids the antioxidant capacity detected in A. barbujana, O. foetens, R. maderensis and P. azorica extracts. These potential reactive flavonoids were identified for A. barbujana, R. maderensis and P. azorica. For R. maderensis a high content (7 mg g^-1 dry weight) of L-ascorbic acid, an already described antioxidant phytomolecule, was found. A high content in selenomethionine (414.35 μg g^-1 dry weight) was obtained for P. arborescens subsp. maderensis extract. This selenocompound is already described as a hydroxyl radical scavenger is reported in this work as also possessing peroxyl radical scavenging capacity. This work is a good illustration of different phytomolecules (flavonoids, organic acids and selenocompounds), presents in leaves of the five traditional medicinal plants endemic to Macaronesia, all exhibiting antioxidant properties. Full article

(This article belongs to the Special Issue Antioxidants)

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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; https://doi.org/10.3390/molecules15042564 - 12 Apr 2010

Cited by 15 | Viewed by 9588

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 [...] Read more.

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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Organocatalytic Michael Addition of 1,3-Dicarbonyl Indane Compounds to Nitrostyrenes

by Zhen-Yu Jiang, Hua-Meng Yang, Ya-Dong Ju, Li Li, Meng-Xian Luo, Guo-Qiao Lai, Jian-Xiong Jiang and Li-Wen Xu

Molecules 2010, 15(4), 2551-2563; https://doi.org/10.3390/molecules15042551 - 12 Apr 2010

Cited by 14 | Viewed by 9889

Abstract

To map out the efficient organocatalyst requirements in the Michael addition of 1,3-dicarbonyl indane compounds to nitrostyrenes, a dozen different amino organocatalysts containing a p-toluenesulfonyl group (Ts) have been evaluated; excellent enantio-selectivities (up to er 92:8) were obtained with a primary amine-based [...] Read more.

To map out the efficient organocatalyst requirements in the Michael addition of 1,3-dicarbonyl indane compounds to nitrostyrenes, a dozen different amino organocatalysts containing a p-toluenesulfonyl group (Ts) have been evaluated; excellent enantio-selectivities (up to er 92:8) were obtained with a primary amine-based Ts-DPEN catalyst and a plausible catalytic reaction mechanism was proposed on the basis of the experimental results. Full article

(This article belongs to the Special Issue Asymmetric Synthesis)

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Synthesis, Antimicrobial, and Anti-inflammatory Activities of Novel 5-(1-Adamantyl)-4-arylideneamino-3-mercapto-1,2,4-triazoles and Related Derivatives

by Mohamed A. Al-Omar, Ebtehal S. Al-Abdullah, Ihsan A. Shehata, Elsayed E. Habib, Tarek M. Ibrahim and Ali A. El-Emam

Molecules 2010, 15(4), 2526-2550; https://doi.org/10.3390/molecules15042526 - 9 Apr 2010

Cited by 103 | Viewed by 10689

Abstract

The reaction of 5-(1-adamantyl)-4-amino-3-mercapto-1,2,4-triazole (5) with various aromatic aldehydes in ethanol or acetic acid yielded the corresponding 4-arylideneamino derivatives 6a–v. Treatment of the 4-(2,6-difluoro- and dichlorobenzylideneamino) derivatives 6o and 6q with 1-substituted piperazines, and formaldehyde solution in ethanol afforded good [...] Read more.

The reaction of 5-(1-adamantyl)-4-amino-3-mercapto-1,2,4-triazole (5) with various aromatic aldehydes in ethanol or acetic acid yielded the corresponding 4-arylideneamino derivatives 6a–v. Treatment of the 4-(2,6-difluoro- and dichlorobenzylideneamino) derivatives 6o and 6q with 1-substituted piperazines, and formaldehyde solution in ethanol afforded good yields of the corresponding 5-(1-adamantyl)-4-(2,6-dihalobenzylideneamino-2-(4-substituted-1-piperazinylmethyl)-1,2,4-triazoline-3-thiones 7a–p. 5-(1-Adamantyl)-4-arylideneamino-2-(4-ethoxycarbonyl-1-piperidylmethyl)-1,2,4-triazoline-3-thiones 8a–n, were similarly prepared via the reaction of the corresponding arylideneamino derivative with ethyl 4-piperidinecarboxylate and formaldehyde solution in ethanol. Compounds 6a–v, 7a–p and 8a–n were tested for in vitro activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Several derivatives showed good or moderate activities, particularly against the tested Gram-positive bacteria. In addition, the in vivo anti-inflammatory activity of 21 compounds was determined using the carrageenan-induced paw oedema method in rats. Compounds 7d, 7g, 7i, 7j, 7l, 8c, 8e and 8l showed good or moderate dose-dependent activity in this area. Full article

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Open AccessCommunication

An Expeditious Synthesis of N-substituted Pyrroles via Microwave-Induced Iodine-Catalyzed Reactions under Solventless Conditions

by Debasish Bandyopadhyay, Sanghamitra Mukherjee and Bimal K. Banik

Molecules 2010, 15(4), 2520-2525; https://doi.org/10.3390/molecules15042520 - 9 Apr 2010

Cited by 50 | Viewed by 10017

Abstract

An expeditious synthesis of N-substituted pyrroles has been developed by reacting 2,5-dimethoxy tetrahydrofuran and several amines using a microwave-induced molecular iodine-catalyzed reaction under solventless conditions. Full article

(This article belongs to the Special Issue Organic Iodine Chemistry)

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300 KiB

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Synthesis and Characterization of Two Novel Organic-Inorganic Compounds Based on Tetrahexyl and Tetraheptyl Ammonium Ions and the Preyssler Anion and Their Catalytic Activities in the Synthesis of 4-Aminopyrazolo[3,4-d]- Pyrimidines

by Fatemeh Farrash Bamoharram

Molecules 2010, 15(4), 2509-2519; https://doi.org/10.3390/molecules15042509 - 8 Apr 2010

Cited by 9 | Viewed by 6421

Abstract

Two novel organic–inorganic compounds based on tetrahexylammonium (THA) and tetraheptylammonium (THPA) ions and the Preyssler anion, [NaP₅W₃₀O₁₁₀]^14-, were synthesized and formulated as (THA)_7.7H_6.3[NaP₅W₃₀O₁₁₀] (A [...] Read more.

Two novel organic–inorganic compounds based on tetrahexylammonium (THA) and tetraheptylammonium (THPA) ions and the Preyssler anion, [NaP₅W₃₀O₁₁₀]^14-, were synthesized and formulated as (THA)_7.7H_6.3[NaP₅W₃₀O₁₁₀] (A) and (THPA)_7.5 H_6.5[N aP₅W₃₀O₁₁₀] (B). The synthesized compounds were characterized by IR, UV, and TGA and used for the catalytic synthesis of 4-aminopyrazolo[3,4,-d]pyrimidine derivatives 2a-2d. Our findings showed efficient catalytic activities for A and B. Full article

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Open AccessArticle

Synthesis and Antimicrobial Activity of Novel Ag-N-Hetero-cyclic Carbene Complexes

by İlknur Özdemir, Emine Özge Özcan, Selami Günal and Nevin Gürbüz

Molecules 2010, 15(4), 2499-2508; https://doi.org/10.3390/molecules15042499 - 8 Apr 2010

Cited by 56 | Viewed by 7242

Abstract

A series of imidazolidinium ligand precursors are metallated with Ag₂O to give silver(I) N-heterocyclic carbene complexes. All compounds were fully characterized by elemental analyses, ¹H-NMR, ¹³C-NMR and IR spectroscopy techniques. All compounds studied in this work were screened [...] Read more.

A series of imidazolidinium ligand precursors are metallated with Ag₂O to give silver(I) N-heterocyclic carbene complexes. All compounds were fully characterized by elemental analyses, ¹H-NMR, ¹³C-NMR and IR spectroscopy techniques. All compounds studied in this work were screened for their in vitro antimicrobial activities against the standard strains: Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and the fungi Candida albicans and Candida tropicalis. The new imidazolidin-2-ylidene silver complexes have been found to display effective antimicrobial activity against a series of bacteria and fungi. Full article

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Molecules, Volume 15, Issue 4 (April 2010) – 64 articles , Pages 2060-2934

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