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

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Open AccessArticle Activity of the Extracts and Neolignans from Piper regnellii against Methicillin-Resistant Staphylococcus aureus (MRSA)
Molecules 2010, 15(4), 2060-2069; doi:10.3390/molecules15042060
Received: 18 January 2010 / Revised: 21 March 2010 / Accepted: 23 March 2010 / Published: 24 March 2010
Cited by 9 | PDF Full-text (663 KB)
Abstract
Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck (Piperaceae) is a medicinal plant traditionally used in Brazil to treat infectious diseases. The extracts obtained of the leaves from P. regnellii were investigated for their antibacterial activities against methicillin-resistant Staphylococcus aureus [...] Read more.
Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck (Piperaceae) is a medicinal plant traditionally used in Brazil to treat infectious diseases. The extracts obtained of the leaves from P. regnellii were investigated for their antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA). The ethyl acetate extract presented a good activity against MRSA, with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of 16 μg/mL. Based on this finding, the ethyl acetate extract was fractionated by silica gel column chromatography into nine fractions. The hexane fraction was active against MRSA (MIC at 4 μg/mL). Further column chromatography separation of the hexane fraction afforded the pure compound eupomatenoid-5. The structure of the compound was established by spectral data (1H and 13C NMR HSQC, HMBC, gNOE, IR and MS). Eupomatenoid-5 was the only compound active on the bacterium. The antibacterial property of P. regnellii extract provides preliminary scientific validation for the traditional medicinal use of this plant. The active compound eupomatenoid-5 should be further studied in animal models to verify in vivo efficacy and toxicity. Full article
Open AccessArticle Inhibitory Effect of Ginkgo Biloba Extract on the Tonus of the Small Intestine and the Colon of Rabbits
Molecules 2010, 15(4), 2079-2086; doi:10.3390/molecules15042079
Received: 15 February 2009 / Revised: 1 March 2010 / Accepted: 18 March 2010 / Published: 24 March 2010
Cited by 2 | PDF Full-text (328 KB)
Abstract
Ginkgo biloba is widely used in folk medicine. Patients very often use the plant preparation with no concern for purity. They also tend to increase the dosage by themselves and this may result in certain insufficiently researched acute effects. Due to this [...] Read more.
Ginkgo biloba is widely used in folk medicine. Patients very often use the plant preparation with no concern for purity. They also tend to increase the dosage by themselves and this may result in certain insufficiently researched acute effects. Due to this extremely widespread application, the aim of this work is an examination of the possible acute effects of Ginkgo bilobaon the motility of the small and the large intestine of rabbits. Тhe effects of Gingium® - a standardized ginkgo biloba extract (GBE) [one milliliter preparation contained 8.8–10.8 mg ginkgo flavonol glycoside and 2.0–2.8 mg lactone ring-containing terpenes (ginkgolides and bilobalides)], on the tonus of isolated segments of the ileum and the colon of rabbits were examined. The experiments were carried out on isolated bowel incisions according to the Magnus method. Data was registered by physiography (Narco-Bio-System). Our results show that GBE (0.006 g/L, - 0.06 g/L) concentration-dependently reduces the tonus of the ileum and the colon of rabbits. Apart from that, GBE reduces the increase of the tonus of the ileum caused by acetylcholine (ACh), but does not change colon tonus intensified by ACh. This indicates that the effects of the used extract in the ileum are predominantly achieved through cholinergic mechanisms, while the relaxant effects in the colon are achieved in some other way. Full article
Open AccessArticle Ultrasound-Assisted Synthesis of Novel 4-(2-Phenyl-1,2,3-Triazol-4-yl)-3,4-Dihydropyrimidin-2(1H)-(Thio)ones Catalyzed by Sm(ClO4)3
Molecules 2010, 15(4), 2087-2095; doi:10.3390/molecules15042087
Received: 28 January 2010 / Revised: 15 March 2010 / Accepted: 24 March 2010 / Published: 24 March 2010
Cited by 22 | PDF Full-text (150 KB)
Abstract
An efficient synthesis of novel 4-(2-phenyl-1,2,3-triazol-4-yl)-3,4-dihydro-pyrimidin-2(1H)-(thio)ones from 1,3-dicarbonyl compounds, 2-phenyl-1,2,3-triazole-4-carbaldehyde and urea or thiourea under ultrasound irradiation and using samarium perchlorate as catalyst is described. Compared with conventional methods, the main advantages of the present methodology are milder conditions, shorter [...] Read more.
An efficient synthesis of novel 4-(2-phenyl-1,2,3-triazol-4-yl)-3,4-dihydro-pyrimidin-2(1H)-(thio)ones from 1,3-dicarbonyl compounds, 2-phenyl-1,2,3-triazole-4-carbaldehyde and urea or thiourea under ultrasound irradiation and using samarium perchlorate as catalyst is described. Compared with conventional methods, the main advantages of the present methodology are milder conditions, shorter reaction times and higher yields. Full article
Open AccessArticle Triterpenes from Stachyurus himalaicus var. himalaicus Hook. f. et Thoms. ex Benth
Molecules 2010, 15(4), 2096-2102; doi:10.3390/molecules15042096
Received: 14 January 2010 / Revised: 24 February 2010 / Accepted: 22 March 2010 / Published: 24 March 2010
Cited by 2 | PDF Full-text (249 KB)
Abstract
Four triterpenes 14, including a new naturally occurring oleanane-type triterpene 1, were isolated by a multi-step chromatography procedure from the leaves and twigs of Stachyurus himalaicus var. himalaicus Hook. f. et Thoms.ex Benth. The structures of the compounds [...] Read more.
Four triterpenes 14, including a new naturally occurring oleanane-type triterpene 1, were isolated by a multi-step chromatography procedure from the leaves and twigs of Stachyurus himalaicus var. himalaicus Hook. f. et Thoms.ex Benth. The structures of the compounds were elucidated by spectroscopic methods, including HRESIMS, 1H- NMR, 13C-NMR, DEPT, HMQC, HMBC and NOESY spectra. All the isolated compounds were evaluated for their in vitro cytotoxic activities against human Hela cell line. Full article
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Open AccessArticle Synthesis and Biological Evaluation of New 5-Fluorouracil-Substituted Ampelopsin Derivatives
Molecules 2010, 15(4), 2114-2123; doi:10.3390/molecules15042114
Received: 19 January 2010 / Revised: 15 March 2010 / Accepted: 22 March 2010 / Published: 24 March 2010
Cited by 7 | PDF Full-text (299 KB) | Supplementary Files
Abstract
This study reports two novel 5-fluorouracil-substituted ampelopsin derivatives. The structures of two new derivatives were characterized by elemental analysis, 1H-NMR, 13C-NMR, IR and MS. Their anticancer activities in vitro against two cancer cell lines, K562 and K562/ADR, were investigated using [...] Read more.
This study reports two novel 5-fluorouracil-substituted ampelopsin derivatives. The structures of two new derivatives were characterized by elemental analysis, 1H-NMR, 13C-NMR, IR and MS. Their anticancer activities in vitro against two cancer cell lines, K562 and K562/ADR, were investigated using the MTT assay, and the results showed that the two new compounds were more effective than reference drugs such as ampelopsin and verapamil. Full article
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Open AccessArticle Assessment of Antioxidant Capacity and Cytotoxicity of Selected Malaysian Plants
Molecules 2010, 15(4), 2139-2151; doi:10.3390/molecules15042139
Received: 22 December 2009 / Revised: 12 February 2010 / Accepted: 3 March 2010 / Published: 25 March 2010
Cited by 23 | PDF Full-text (206 KB)
Abstract
Thirteen Malaysian plants; Artocarpus champeden, Azadirachta indica, Fragaria x ananassa, Garcinia mangostana, Lawsonia inermis, Mangifera indica, Nephelium lappaceum, Nephelium mutobile, Peltophorum pterocarpum, Psidium guajava and Syzygium aqueum, selected for their use in traditional medicine, were subjected to a variety of assays. [...] Read more.
Thirteen Malaysian plants; Artocarpus champeden, Azadirachta indica, Fragaria x ananassa, Garcinia mangostana, Lawsonia inermis, Mangifera indica, Nephelium lappaceum, Nephelium mutobile, Peltophorum pterocarpum, Psidium guajava and Syzygium aqueum, selected for their use in traditional medicine, were subjected to a variety of assays. Antioxidant capability, total phenolic content, elemental composition, as well as it cytotoxity to several cell lines of the aqueous and ethanolic extracts from different parts of these selected Malaysian plants were determined. In general, the ethanolic extracts were better free radical scavengers than the aqueous extracts and some of the tested extracts were even more potent than a commercial grape seed preparation. Similar results were seen in the lipid peroxidation inhibition studies. Our findings also showed a strong correlation of antioxidant activity with the total phenolic content. These extracts when tested for its heavy metals content, were found to be below permissible value for nutraceutical application. In addition, most of the extracts were found not cytotoxic to 3T3 and 4T1 cells at concentrations as high as 100 μg/mL. We conclude that although traditionally these plants are used in the aqueous form, its commercial preparation could be achieved using ethanol since a high total phenolic content and antioxidant activity is associated with this method of preparation. Full article
(This article belongs to the Special Issue Antioxidants)
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Open AccessArticle Antioxidant Activity of Polysaccharide-enriched Fractions Extracted from Pulp Tissue of Litchi Chinensis Sonn.
Molecules 2010, 15(4), 2152-2165; doi:10.3390/molecules15042152
Received: 17 December 2009 / Revised: 3 March 2010 / Accepted: 22 March 2010 / Published: 25 March 2010
Cited by 33 | PDF Full-text (294 KB)
Abstract
Natural antioxidants such as polysaccharides with strong antioxidant activities are used to protect against oxidative damage, yet little is known so far about the antioxidant effects of litchi fruit polysaccharides. In the present study, four different polysaccharide-enriched fractions were isolated from litchi [...] Read more.
Natural antioxidants such as polysaccharides with strong antioxidant activities are used to protect against oxidative damage, yet little is known so far about the antioxidant effects of litchi fruit polysaccharides. In the present study, four different polysaccharide-enriched fractions were isolated from litchi pulp tissue and partially purified by a stepwise method of ethyl alcohol (EtOH) precipitation. Their chemical and physical characteristics were determined by chemical methods, gas chromatography and IR spectrophotometry. Antioxidant activities of these fractions were investigated using various in vitro assay systems. These four polysaccharide-enriched fractions exhibited a dose-dependent free radical scavenging activity as shown by their DPPH radical, superoxide anion and hydroxyl radical inhibition, chelating ability and reducing power. Among the different fractions, LFP-III showed the strongest scavenging activity against DPPH radical, superoxide and hydroxyl radicals and chelating ability. These findings suggest litchi polysaccharides from pulp tissue have potential as functional foods with enhanced antioxidant activity. Full article
Open AccessArticle Selective Heck Arylation of Cyclohexene with Homogeneous and Heterogeneous Palladium Catalysts
Molecules 2010, 15(4), 2166-2177; doi:10.3390/molecules15042166
Received: 27 January 2010 / Revised: 10 March 2010 / Accepted: 23 March 2010 / Published: 25 March 2010
Cited by 13 | PDF Full-text (415 KB)
Abstract
Palladium catalysts containing Pd(II) supported on Al2O3 and alumina-based mixed oxides, Al2O3-ZrO2, Al2O3-CeO2, and Al2O3-Fe2O3, are very effective in [...] Read more.
Palladium catalysts containing Pd(II) supported on Al2O3 and alumina-based mixed oxides, Al2O3-ZrO2, Al2O3-CeO2, and Al2O3-Fe2O3, are very effective in the Heck coupling of iodobenzene with cyclohexene in DMF solution. The best results, up to 81% of monoarylated products with a selectivity to 4-phenylcyclohexene (3) close to 90% were obtained with KOH as a base. The catalytic activity of palladium supported on alumina-based oxides was compared with that of homogeneous precursors, such as Pd(OAc)2 and PdCl2(PhCN)2, used in [Bu4N]Br as the reaction medium. Under such conditions homogeneous systems were more selective and produced up to 60% of monoarylated products with a selectivity to 3 close to 60%. Full article
(This article belongs to the Special Issue Heck Coupling)
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Open AccessCommunication Chemical Constituents of Excoecaria acerifolia and Their Bioactivities
Molecules 2010, 15(4), 2178-2186; doi:10.3390/molecules15042178
Received: 29 December 2009 / Revised: 12 February 2010 / Accepted: 8 March 2010 / Published: 26 March 2010
Cited by 7 | PDF Full-text (237 KB)
Abstract
A new kaurane diterpenoid, 3α,18-dihydroxy-3β,20-epoxykaur-15-ene (1), was isolated from the aerial parts of Excoecaria acerifolia (Euphorbiaceae) together with 16 known compounds. Their structures were identified by extensive spectral analysis, especially 2D NMR techniques. Antiangiogenic effects of compounds 1-6 and 9-17 [...] Read more.
A new kaurane diterpenoid, 3α,18-dihydroxy-3β,20-epoxykaur-15-ene (1), was isolated from the aerial parts of Excoecaria acerifolia (Euphorbiaceae) together with 16 known compounds. Their structures were identified by extensive spectral analysis, especially 2D NMR techniques. Antiangiogenic effects of compounds 1-6 and 9-17 were evaluated using a zebrafish model, with compound 9 being active in this bioassay. At the same time, compounds 4, 6, 10, 11 showed activity in inhibiting the growth of A549 lung cancer cells, and the compound 10 also showed apoptosis-inducing effects on A549 lung cancer cells. Full article
Open AccessArticle Novel Indole-Based Analogs of Melatonin: Synthesis and in Vitro Antioxidant Activity Studies
Molecules 2010, 15(4), 2187-2202; doi:10.3390/molecules15042187
Received: 19 January 2010 / Revised: 15 March 2010 / Accepted: 23 March 2010 / Published: 29 March 2010
Cited by 32 | PDF Full-text (285 KB)
Abstract
The aim of this study was to synthesize and examine possible in vitro antioxidant effects of indole-based melatonin analogue compounds. As a part of our ongoing study nineteen indole hydrazide/hydrazone derivatives were synthesized, characterized and their in vitro antioxidant activity was investigated [...] Read more.
The aim of this study was to synthesize and examine possible in vitro antioxidant effects of indole-based melatonin analogue compounds. As a part of our ongoing study nineteen indole hydrazide/hydrazone derivatives were synthesized, characterized and their in vitro antioxidant activity was investigated by three different assays: by evaluating their reducing effect against oxidation of a redox sensitive fluorescent probe, by examining their protective effect against H2O2-induced membrane lipid peroxidation and by determining their inhibitory effect on AAPH–induced hemolysis of human erythrocytes. The results indicated significant strong antioxidant activity for most of the compounds, when compared to melatonin. Full article
(This article belongs to the Special Issue Structure-Based Drug Design)
Open AccessArticle Gold(I) Complexes of N-Heterocyclic Carbene Ligands Containing Benzimidazole: Synthesis and Antimicrobial Activity
Molecules 2010, 15(4), 2203-2210; doi:10.3390/molecules15042203
Received: 15 March 2010 / Revised: 23 March 2010 / Accepted: 26 March 2010 / Published: 29 March 2010
Cited by 27 | PDF Full-text (352 KB)
Abstract
Gold(I) N-heterocyclic carbene (NHC) complexes were obtained in good yields from the corresponding silver complexes by treatment with [AuCl(PPh3)] following the commonly used silver carbene transfer route. The silver complexes were synthesized from the benzimidazolium halide salts by the [...] Read more.
Gold(I) N-heterocyclic carbene (NHC) complexes were obtained in good yields from the corresponding silver complexes by treatment with [AuCl(PPh3)] following the commonly used silver carbene transfer route. The silver complexes were synthesized from the benzimidazolium halide salts by the in situ reactions with Ag2O in dichloromethane as a solvent at room temperature. All gold complexes have been characterized by 1H-NMR, 13C-NMR and IR spectroscopy and elemental analysis. Au-NHC complexes were evaluated for their in vitro antimicrobial activity against a variety of Gram-positive and Gram-negative bacteria and fungal species. Full article
Open AccessArticle Synthesis and Antimicrobial Activity of New 4-Heteroarylamino Coumarin Derivatives Containing Nitrogen and Sulfur as Heteroatoms
Molecules 2010, 15(4), 2246-2256; doi:10.3390/molecules15042246
Received: 17 March 2010 / Revised: 26 March 2010 / Accepted: 29 March 2010 / Published: 30 March 2010
Cited by 22 | PDF Full-text (278 KB)
Abstract
Synthesis, spectral analysis and bioactivity of new coumarin derivatives are described in this paper. Eight new coumarin derivatives were synthesized in moderate to good yields by condensation of 4-chloro-3-nitrocoumarin and the corresponding heteroarylamine. The synthesized compounds were tested for their in vitro [...] Read more.
Synthesis, spectral analysis and bioactivity of new coumarin derivatives are described in this paper. Eight new coumarin derivatives were synthesized in moderate to good yields by condensation of 4-chloro-3-nitrocoumarin and the corresponding heteroarylamine. The synthesized compounds were tested for their in vitro antimicrobial activity, in a standard disk diffusion assay, against thirteen strains of bacteria and three fungal strains. They have shown a wide range of activity - from one completely inactive compound to medium active ones. Full article
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Open AccessArticle Controlled Release of 5-Aminosalicylic Acid (5-ASA) from New Biodegradable Polyurethanes
Molecules 2010, 15(4), 2257-2268; doi:10.3390/molecules15042257
Received: 23 February 2010 / Revised: 11 March 2010 / Accepted: 22 March 2010 / Published: 30 March 2010
Cited by 5 | PDF Full-text (253 KB)
Abstract
Segmented polyurethanes containing azo aromatic groups in the main chain were synthesized by reaction of 3,3'-azobis(6-hydroxybenzoic acid) (ABHB), 5-[4-(hydroxyphenyl)azo] salicylic acid (HPAS), and 5-[1-hydroxynaphthyl)azo] salicylic acid (HNAS) with hexamethylenediisocyanate (HDI). All synthesized monomers and polymers were characterized by elemental analysis, FTIR, 1 [...] Read more.
Segmented polyurethanes containing azo aromatic groups in the main chain were synthesized by reaction of 3,3'-azobis(6-hydroxybenzoic acid) (ABHB), 5-[4-(hydroxyphenyl)azo] salicylic acid (HPAS), and 5-[1-hydroxynaphthyl)azo] salicylic acid (HNAS) with hexamethylenediisocyanate (HDI). All synthesized monomers and polymers were characterized by elemental analysis, FTIR, 1H-NMR spectra, TGA and DSC analysis. All the synthesized azo polymers showed good thermal stability and the onset decomposition temperature of all these polymers was found to be above 195 ºC under nitrogen atmosphere.The release of 5-ASA under physiological conditions (pH = 7.8 and pH = 1.5) was investigated at body temperature (37 ºC). The release rate of 5-ASA increased with increasing pH (i.e., 7.8 > 1.5). Full article
Open AccessArticle Synthesis of Dihydrouracils Spiro-Fused to Pyrrolidines: Druglike Molecules Based on the 2-Arylethyl Amine Scaffold
Molecules 2010, 15(4), 2269-2301; doi:10.3390/molecules15042269
Received: 5 February 2010 / Revised: 26 March 2010 / Accepted: 30 March 2010 / Published: 30 March 2010
Cited by 6 | PDF Full-text (300 KB)
Abstract
The synthesis of a small library of dihydrouracils spiro-fused to pyrrolidines is described. These compounds are synthesized from b-aryl pyrrolidines, providing products with the 2-arylethyl amine moiety, a structural feature often encountered in compounds active in the central nervous system. The b-aryl [...] Read more.
The synthesis of a small library of dihydrouracils spiro-fused to pyrrolidines is described. These compounds are synthesized from b-aryl pyrrolidines, providing products with the 2-arylethyl amine moiety, a structural feature often encountered in compounds active in the central nervous system. The b-aryl pyrrolidines are synthesized through a three-step methodology that includes a Knoevenagel condensation reaction, a 1,3-dipolar cycloaddition reaction, and a nitrile reduction. Full article
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Open AccessArticle Effect of Sugars on Artemisinin Production in Artemisia annua L.: Transcription and Metabolite Measurements
Molecules 2010, 15(4), 2302-2318; doi:10.3390/molecules15042302
Received: 16 December 2009 / Revised: 20 March 2010 / Accepted: 23 March 2010 / Published: 30 March 2010
Cited by 18 | PDF Full-text (233 KB)
Abstract
The biosynthesis of the valuable sesquiterpene anti-malarial, artemisinin, is known to respond to exogenous sugar concentrations. Here young Artemisia annua L. seedlings (strain YU) were used to measure the transcripts of six key genes in artemisinin biosynthesis in response to growth on [...] Read more.
The biosynthesis of the valuable sesquiterpene anti-malarial, artemisinin, is known to respond to exogenous sugar concentrations. Here young Artemisia annua L. seedlings (strain YU) were used to measure the transcripts of six key genes in artemisinin biosynthesis in response to growth on sucrose, glucose, or fructose. The measured genes are: from the cytosolic arm of terpene biosynthesis, 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR), farnesyl disphosphate (FPS); from the plastid arm of terpene biosynthesis, 1-deoxyxylulose-5-phosphate synthase (DXS), 1-deoxyxylulouse 5-phosphate reductoisomerase (DXR); from the dedicated artemisinin pathway amorpha-4,11-diene synthase (ADS), and the P450, CYP71AV1 (CYP). Changes in intracellular concentrations of artemisinin (AN) and its precursors, dihydroartemisinic acid (DHAA), artemisinic acid (AA), and arteannuin B (AB) were also measured in response to these three sugars. FPS, DXS, DXR, ADS and CYP transcript levels increased after growth in glucose, but not fructose. However, the kinetics of these transcripts over 14 days was very different. AN levels were significantly increased in glucose-fed seedlings, while levels in fructose-fed seedlings were inhibited; in both conditions this response was only observed for 2 days after which AN was undetectable until day 14. In contrast to AN, on day 1 AB levels doubled in seedlings grown in fructose compared to those grown in glucose. Results showed that transcript level was often negatively correlated with the observed metabolite concentrations. When seedlings were gown in increasing levels of AN, some evidence of a feedback mechanism emerged, but mainly in the inhibition of AA production. Together these results show the complex interplay of exogenous sugars on the biosynthesis of artemisinin in young A. annua seedlings. Full article
Open AccessArticle Isolation and Characterization of a New Ginsenoside from the Fresh Root of Panax Ginseng
Molecules 2010, 15(4), 2319-2325; doi:10.3390/molecules15042319
Received: 8 March 2010 / Revised: 23 March 2010 / Accepted: 26 March 2010 / Published: 30 March 2010
Cited by 20 | PDF Full-text (163 KB)
Abstract
A new saponin, malonylginsenoside Ra3, was isolated from the fresh root of Panax ginseng, along with four known ginsenosides. The new compound was identified as (20S)-protopanaxadiol-3-O-(6-O-malonyl-β-D-glucopyranosyl(1→2)-β-D-glucopyranoside-20-O-β [...] Read more.
A new saponin, malonylginsenoside Ra3, was isolated from the fresh root of Panax ginseng, along with four known ginsenosides. The new compound was identified as (20S)-protopanaxadiol-3-O-(6-O-malonyl-β-D-glucopyranosyl(1→2)-β-D-glucopyranoside-20-O-β-D-xylopyranosyl(1→3)-β-D-glucopyranosyl(1→6)-β-D-glucopyranoside on the basis of extensive 1D and 2D NMR as well as HRESI-MS spectroscopic data analysis. Full article
Open AccessArticle Chemical Composition and Biological Properties of Rhododendron anthopogon Essential Oil
Molecules 2010, 15(4), 2326-2338; doi:10.3390/molecules15042326
Received: 2 February 2010 / Revised: 16 March 2010 / Accepted: 29 March 2010 / Published: 31 March 2010
Cited by 15 | PDF Full-text (151 KB)
Abstract
The essential oil of Rhododendron anthopogon was investigated by GC-MS, and seventeen compounds (representing approximately 98% of the oil) were identified. The major components of the aerial parts of the oil were the monoterpenes α-pinene, β-pinene, limonene and the sesquiterpene δ-cadinene. Biological [...] Read more.
The essential oil of Rhododendron anthopogon was investigated by GC-MS, and seventeen compounds (representing approximately 98% of the oil) were identified. The major components of the aerial parts of the oil were the monoterpenes α-pinene, β-pinene, limonene and the sesquiterpene δ-cadinene. Biological studies revealed a weak topical anti-inflammatory activity; a significant killing effect against some Gram-positive reference strains: Staphylococcus aureus, Enterococcusfecalis, Bacillus subtilis was measured; Mycobacterium tuberculosis reference strain and a clinical isolate of Candida, C. pseudotropicalis were killed by as low as 0.04% (v/v) essential oil. Moreover, the oil was able to reduce cancer cell growth independently of the cell line and the treatment protocols used. Full article
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Open AccessArticle (6,7-Dimethoxy-4-methylisoquinolinyl)-(4’-methoxyphenyl)-methanone, a New Benzylisoquinoline Alkaloid from Beilschmiedia brevipes
Molecules 2010, 15(4), 2339-2346; doi:10.3390/molecules15042339
Received: 19 January 2010 / Revised: 8 February 2010 / Accepted: 1 March 2010 / Published: 31 March 2010
Cited by 8 | PDF Full-text (341 KB)
Abstract
The leaves of Beilschmiedia brevipes provided a new benzylisoquinoline alkaloid: (6,7-dimethoxy-4-methylisoquinolinyl)-(4’-methoxyphenyl)-methanone (1) and O,O-dimethylannocherin A (2), a new natural compound which has been synthesized before. Complete 1H- and 13C-NMR data of both compounds [...] Read more.
The leaves of Beilschmiedia brevipes provided a new benzylisoquinoline alkaloid: (6,7-dimethoxy-4-methylisoquinolinyl)-(4’-methoxyphenyl)-methanone (1) and O,O-dimethylannocherin A (2), a new natural compound which has been synthesized before. Complete 1H- and 13C-NMR data of both compounds were reported. The structures were established through various spectroscopic methods notably 1D- and 2D-NMR, UV, IR and HRESIMS. Full article
Open AccessArticle Boronate Derivatives of Functionally Diverse Catechols: Stability Studies
Molecules 2010, 15(4), 2347-2356; doi:10.3390/molecules15042347
Received: 27 January 2010 / Revised: 25 February 2010 / Accepted: 22 March 2010 / Published: 31 March 2010
Cited by 9 | PDF Full-text (301 KB)
Abstract Benzeneboronate of catecholic carboxyl methyl esters, N-acetyldopamine, coumarin and catechol estrogens were prepared as crystalline derivatives in high yield. Related catechol compounds with extra polar functional group(s) (OH, NH2) do not form or only partially form unstable cyclic boronate derivatives. Full article
Open AccessArticle Excitation and Circular Dichroism Spectra of (+)-(S,S)-bis(2-Methylbutyl)chalcogenides
Molecules 2010, 15(4), 2357-2373; doi:10.3390/molecules15042357
Received: 10 February 2010 / Revised: 1 March 2010 / Accepted: 26 March 2010 / Published: 31 March 2010
Cited by 2 | PDF Full-text (613 KB)
Abstract
Theoretical electronic spectra and natural circular dichroism (CD) spectra of (+)-(S,S)-bis(2-methylbutyl)chalcogenides, Ch[CH2CH(CH3)C2H5]2 (Ch = S, Se, and Te), were calculated by the symmetry adapted cluster (SAC) and SAC-configuration interaction [...] Read more.
Theoretical electronic spectra and natural circular dichroism (CD) spectra of (+)-(S,S)-bis(2-methylbutyl)chalcogenides, Ch[CH2CH(CH3)C2H5]2 (Ch = S, Se, and Te), were calculated by the symmetry adapted cluster (SAC) and SAC-configuration interaction (SAC-CI) methods. Whereas the calculated CD spectrum for each stable conformation itself did not reproduce the corresponding experimental one, their Boltzmann-averaged spectra showed good agreement with the experimental results. We provided the assignment for each spectral band according to our calculation results. For the telluride compound, temperature dependence of the CD spectra was experimentally observed due to variation in the Boltzmann factor, and our calculations reproduced it qualitatively. The spectral features that we could not reproduce can be attributed to triplet transitions through the spin-orbit interaction effects as well as accuracy incompleteness on the calculation conditions. Full article
(This article belongs to the Special Issue Selenium and Tellurium Chemistry)
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Open AccessArticle Glut1 and Glut3 as Potential Prognostic Markers for Oral Squamous Cell Carcinoma
Molecules 2010, 15(4), 2374-2387; doi:10.3390/molecules15042374
Received: 25 February 2010 / Revised: 24 March 2010 / Accepted: 29 March 2010 / Published: 1 April 2010
Cited by 45 | PDF Full-text (511 KB)
Abstract
We associated clinical-pathological features of 142 OSCC with the expression pattern of GLUT1 and GLUT3 in order to estimate their prognostic value. Methods: Clinical-pathological features and overall survival data of 142 patients with Oral Squamous Cell Carcinoma (OSCC) were retrospectively reviewed from [...] Read more.
We associated clinical-pathological features of 142 OSCC with the expression pattern of GLUT1 and GLUT3 in order to estimate their prognostic value. Methods: Clinical-pathological features and overall survival data of 142 patients with Oral Squamous Cell Carcinoma (OSCC) were retrospectively reviewed from A.C.Camargo hospital records. A tissue microarray (TMA) was built for the immunohistochemical (IHC) analysis of GLUT 1 and GLUT 3. IHC results were evaluated according to the staining pattern and number of positive cells. Results: GLUT 1 was over expressed in 50.3% of OSSC cases showing membrane staining pattern. However, nuclear expression was observed in 49.7% of the analyzed cases. GLUT 3 over expression was detected in 21.1% of OSCC cases. The pattern of GLUT 1 expression showed significant association with alcohol consumption (p = 0.004). Positive cell membrane GLUT 3 protein expression was associated with advanced clinic-staging of tumours (p = 0.005) as well as with vascular embolization (p = 0.005). Positive expression of GLUT 3 was associated with unfavorable free-disease survival (p = 0.021). Conclusion: GLUT1 and GLUT3 protein expression evaluated by immunohistochemistry are, significantly, indicators of poor prognosis outcome in oral squamous cell carcinoma, probably due to the enhanced glycolytic metabolism of more aggressive neoplastic cells. Full article
Open AccessArticle Synthesis and Physico-Chemical Properties of New Tetraethylammonium-Based Amino Acid Chiral Ionic Liquids
Molecules 2010, 15(4), 2388-2397; doi:10.3390/molecules15042388
Received: 12 February 2010 / Revised: 15 March 2010 / Accepted: 22 March 2010 / Published: 5 April 2010
Cited by 10 | PDF Full-text (294 KB)
Abstract
This paper reports the synthesis of a series of new tetraethylammonium-based amino acid chiral ionic liquids (CILs). Their physico-chemical properties, including melting point, thermal stability, viscosity and ionic conductivity, have been comprehensively studied. The obtained results indicated that the decomposition for these [...] Read more.
This paper reports the synthesis of a series of new tetraethylammonium-based amino acid chiral ionic liquids (CILs). Their physico-chemical properties, including melting point, thermal stability, viscosity and ionic conductivity, have been comprehensively studied. The obtained results indicated that the decomposition for these salts proceeds in one step and the temperature of decomposition (Tonset) is in the range of 168–210 °C. Several new CILs prepared in this work showed high ionic conductivity compared to the amino acid ionic liquids (AAILs) found in the literature. Full article
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Open AccessArticle Pellitorine, a Potential Anti-Cancer Lead Compound against HL60 and MCT-7 Cell Lines and Microbial Transformation of Piperine from Piper Nigrum
Molecules 2010, 15(4), 2398-2404; doi:10.3390/molecules15042398
Received: 12 January 2010 / Revised: 9 March 2010 / Accepted: 18 March 2010 / Published: 5 April 2010
Cited by 16 | PDF Full-text (255 KB)
Abstract
Pellitorine (1), which was isolated from the roots of Piper nigrum, showed strong cytotoxic activities against HL60 and MCT-7 cell lines. Microbial transformation of piperine (2) gave a new compound 5-[3,4-(methylenedioxy)phenyl]-pent-2-ene piperidine (3). Two other [...] Read more.
Pellitorine (1), which was isolated from the roots of Piper nigrum, showed strong cytotoxic activities against HL60 and MCT-7 cell lines. Microbial transformation of piperine (2) gave a new compound 5-[3,4-(methylenedioxy)phenyl]-pent-2-ene piperidine (3). Two other alkaloids were also found from Piper nigrum. They are (E)-1-[3’,4’-(methylenedioxy)cinnamoyl]piperidine (4) and 2,4-tetradecadienoic acid isobutyl amide (5). These compounds were isolated using chromatographic methods and their structures were elucidated using MS, IR and NMR techniques. Full article
Open AccessArticle Synthesis and Antimicrobial Activities of Some New 1,2,4-Triazole Derivatives
Molecules 2010, 15(4), 2427-2438; doi:10.3390/molecules15042427
Received: 12 February 2010 / Revised: 9 March 2010 / Accepted: 22 March 2010 / Published: 8 April 2010
Cited by 50 | PDF Full-text (223 KB)
Abstract
Some novel 4,5-disubstituted-2,4-dihydro-3H-1,2,4-triazol-3-one (3, 6, 8, 9) derivatives and or 3-(4-methylphenyl)[1,2,4]triazolo[3,4-b][1,3]benzoxazole (5) were synthesized from the reaction of various ester ethoxycarbonylhydrazones (1a-e) with several primary amines. The synthesis of 4-amino-5-(4-chlorophenyl)-2-[(5-mercapto-1,3,4-oxadiazol-2-yl)methyl]-2,4-dihydro-3H-1,2,4-triazol-3-one [...] Read more.
Some novel 4,5-disubstituted-2,4-dihydro-3H-1,2,4-triazol-3-one (3, 6, 8, 9) derivatives and or 3-(4-methylphenyl)[1,2,4]triazolo[3,4-b][1,3]benzoxazole (5) were synthesized from the reaction of various ester ethoxycarbonylhydrazones (1a-e) with several primary amines. The synthesis of 4-amino-5-(4-chlorophenyl)-2-[(5-mercapto-1,3,4-oxadiazol-2-yl)methyl]-2,4-dihydro-3H-1,2,4-triazol-3-one (13) was performed starting from 4-Amino-5-(4-chlorophenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (2) by four steps; then 13 was converted to the corresponding Schiff base (14) by using 4-methoxybenzaldehyde. Finally, two Mannich base derivatives of 14 were obtained by using morpholine or methyl piperazine as amine component. All newly synthesized compounds were screened for their antimicrobial activities and some of which were found to possess good or moderate activities against the test microorganisms. Full article
Open AccessArticle Thermal Analysis Applied to Verapamil Hydrochloride Characterization in Pharmaceutical Formulations
Molecules 2010, 15(4), 2439-2452; doi:10.3390/molecules15042439
Received: 8 January 2010 / Revised: 20 February 2010 / Accepted: 5 March 2010 / Published: 8 April 2010
Cited by 17 | PDF Full-text (223 KB)
Abstract
Thermogravimetry (TG) and differential scanning calorimetry (DSC) are useful techniques that have been successfully applied in the pharmaceutical industry to reveal important information regarding the physicochemical properties of drug and excipient molecules such as polymorphism, stability, purity, formulation compatibility among others. Verapamil [...] Read more.
Thermogravimetry (TG) and differential scanning calorimetry (DSC) are useful techniques that have been successfully applied in the pharmaceutical industry to reveal important information regarding the physicochemical properties of drug and excipient molecules such as polymorphism, stability, purity, formulation compatibility among others. Verapamil hydrochloride shows thermal stability up to 180 °C and melts at 146 °C, followed by total degradation. The drug is compatible with all the excipients evaluated. The drug showed degradation when subjected to oxidizing conditions, suggesting that the degradation product is 3,4-dimethoxybenzoic acid derived from alkyl side chain oxidation. Verapamil hydrochloride does not present the phenomenon of polymorphism under the conditions evaluated. Assessing the drug degradation kinetics, the drug had a shelf life (t90) of 56.7 years and a pharmaceutical formulation showed t90 of 6.8 years showing their high stability. Full article
Open AccessArticle Bifunctional Catalysis: Direct Reductive Amination of Aliphatic Ketones with an Iridium-Phosphate Catalyst
Molecules 2010, 15(4), 2453-2472; doi:10.3390/molecules15042453
Received: 9 March 2010 / Revised: 29 March 2010 / Accepted: 2 April 2010 / Published: 8 April 2010
Cited by 31 | PDF Full-text (316 KB)
Abstract
Chiral amines are one of the ubiquitous functional groups in fine chemical, pharmaceutical and agrochemical products, and the most convenient, economical, and eco-benign synthetic pathway to these amines is direct asymmetric reductive amination (DARA) of prochiral ketones. This paper shows that a [...] Read more.
Chiral amines are one of the ubiquitous functional groups in fine chemical, pharmaceutical and agrochemical products, and the most convenient, economical, and eco-benign synthetic pathway to these amines is direct asymmetric reductive amination (DARA) of prochiral ketones. This paper shows that a wide range of aliphatic ketones can be directly aminated under hydrogenation conditions, affording chiral amines with good to excellent yields and with enantioselectivities up to 96% ee. The catalysis is effected by the cooperative action of a cationic Cp*Ir(III) complex and its phosphate counteranion. Full article
(This article belongs to the Special Issue Bifunctional Catalysis)
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Open AccessArticle Scyphiphin C, a New Iridoid from Scyphiphora hydrophyllacea
Molecules 2010, 15(4), 2473-2477; doi:10.3390/molecules15042473
Received: 23 February 2010 / Revised: 16 March 2010 / Accepted: 1 April 2010 / Published: 8 April 2010
Cited by 7 | PDF Full-text (73 KB)
Abstract
Chemical investigation of the ethanol extract of the aerial parts of Scyphiphora hydrophyllacea Gaertn.collected in Hainan Province of China resulted in the isolation of a new iridoid, scyphiphin C (1) and a known iridoid glycoside, shanzhiside methyl ester (2 [...] Read more.
Chemical investigation of the ethanol extract of the aerial parts of Scyphiphora hydrophyllacea Gaertn.collected in Hainan Province of China resulted in the isolation of a new iridoid, scyphiphin C (1) and a known iridoid glycoside, shanzhiside methyl ester (2). Their structures were elucidated by a study of their physical and spectral data. Full article
Open AccessArticle New 3H-Indole Synthesis by Fischer’s Method. Part I.
Molecules 2010, 15(4), 2491-2498; doi:10.3390/molecules15042491
Received: 6 February 2010 / Revised: 12 March 2010 / Accepted: 19 March 2010 / Published: 8 April 2010
Cited by 8 | PDF Full-text (144 KB)
Abstract
Methyl indolenines (4a-c) and(5a-c) were prepared in high yield by a Fischer indole synthesis reaction of o,m-tolylhydrazine hydrochlorides (1a-b) with isopropyl methyl ketone (2) and 2-methylcyclohexanone (3) in acetic acid at [...] Read more.
Methyl indolenines (4a-c) and(5a-c) were prepared in high yield by a Fischer indole synthesis reaction of o,m-tolylhydrazine hydrochlorides (1a-b) with isopropyl methyl ketone (2) and 2-methylcyclohexanone (3) in acetic acid at room temperature. o,p- Nitrophenylhydrazines (1c-d) were reacted with 2-methylcyclohexanone (3) in acetic acid at reflux to give nitroindolenines (5d-e), while the attempted reactions of o,p-nitrohydrazines with isopropyl methyl ketone (2) in acetic acid were not successful. Compounds(1c-d) were reacted with isopropyl methyl ketone (2) in acetic acid/HCl to give 2,3,3-trimethyl-5-nitro-indolenine (4e) and 2,3,3-trimethyl-7-nitroindolenine (4d). Full article
Open AccessArticle Synthesis and Antimicrobial Activity of Novel Ag-N-Hetero-cyclic Carbene Complexes
Molecules 2010, 15(4), 2499-2508; doi:10.3390/molecules15042499
Received: 16 March 2010 / Revised: 29 March 2010 / Accepted: 7 April 2010 / Published: 8 April 2010
Cited by 33 | PDF Full-text (343 KB)
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 [...] 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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Open AccessArticle 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
Molecules 2010, 15(4), 2509-2519; doi:10.3390/molecules15042509
Received: 5 February 2010 / Revised: 17 March 2010 / Accepted: 8 April 2010 / Published: 8 April 2010
Cited by 7 | PDF Full-text (300 KB)
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)7.7H6.3 [NaP5W30O110] ( [...] 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)7.7H6.3 [NaP5W30O110] (A) and (THPA)7.5 H6.5[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
Open AccessCommunication An Expeditious Synthesis of N-substituted Pyrroles via Microwave-Induced Iodine-Catalyzed Reactions under Solventless Conditions
Molecules 2010, 15(4), 2520-2525; doi:10.3390/molecules15042520
Received: 20 January 2010 / Revised: 1 March 2010 / Accepted: 2 April 2010 / Published: 9 April 2010
Cited by 27 | PDF Full-text (205 KB)
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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Open AccessArticle Synthesis, Antimicrobial, and Anti-inflammatory Activities of Novel 5-(1-Adamantyl)-4-arylideneamino-3-mercapto-1,2,4-triazoles and Related Derivatives
Molecules 2010, 15(4), 2526-2550; doi:10.3390/molecules15042526
Received: 8 March 2010 / Revised: 29 March 2010 / Accepted: 2 April 2010 / Published: 9 April 2010
Cited by 52 | PDF Full-text (234 KB)
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 [...] 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
Open AccessArticle Organocatalytic Michael Addition of 1,3-Dicarbonyl Indane Compounds to Nitrostyrenes
Molecules 2010, 15(4), 2551-2563; doi:10.3390/molecules15042551
Received: 9 December 2009 / Revised: 3 March 2010 / Accepted: 19 March 2010 / Published: 12 April 2010
Cited by 9 | PDF Full-text (315 KB)
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 [...] 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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Open AccessArticle Dendrimers Containing Ferrocene and Porphyrin Moieties: Synthesis and Cubic Non-Linear Optical Behavior
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
Cited by 9 | PDF Full-text (237 KB)
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 [...] 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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Open AccessArticle Antioxidant Capacity of Macaronesian Traditional Medicinal Plants
Molecules 2010, 15(4), 2576-2592; doi:10.3390/molecules15042576
Received: 9 February 2010 / Revised: 30 March 2010 / Accepted: 6 April 2010 / Published: 12 April 2010
Cited by 28 | PDF Full-text (607 KB)
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 (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 A New Sulfated α-Ionone Glycoside from Sonchus erzincanicus Matthews
Molecules 2010, 15(4), 2593-2599; doi:10.3390/molecules15042593
Received: 13 March 2010 / Accepted: 22 March 2010 / Published: 12 April 2010
Cited by 12 | PDF Full-text (245 KB) | Supplementary Files
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 [...] 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
Open AccessArticle Chemical Composition and Insecticidal Activity against Sitophilus zeamais of the Essential Oils of Artemisia capillaris and Artemisia mongolica
Molecules 2010, 15(4), 2600-2608; doi:10.3390/molecules15042600
Received: 18 March 2010 / Revised: 8 April 2010 / Accepted: 9 April 2010 / Published: 12 April 2010
Cited by 35 | PDF Full-text (148 KB)
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 [...] 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
Open AccessArticle High-Throughput Behavioral Screens: the First Step towards Finding Genes Involved in Vertebrate Brain Function Using Zebrafish
Molecules 2010, 15(4), 2609-2622; doi:10.3390/molecules15042609
Received: 9 February 2010 / Revised: 26 March 2010 / Accepted: 7 April 2010 / Published: 12 April 2010
Cited by 89 | PDF Full-text (199 KB)
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 [...] 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)
Open AccessArticle Influence of Solvent, Electron Acceptors and Arenes on Photochemical Decarboxylation of Free Carboxylic Acids via Single Electron Transfer (SET)
Molecules 2010, 15(4), 2623-2630; doi:10.3390/molecules15042623
Received: 15 March 2010 / Revised: 2 April 2010 / Accepted: 7 April 2010 / Published: 12 April 2010
Cited by 17 | PDF Full-text (71 KB)
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, [...] 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 New Chiral Phosphoramidite Complexes of Iron as Catalytic Precursors in the Oxidation of Activated Methylene Groups
Molecules 2010, 15(4), 2631-2650; doi:10.3390/molecules15042631
Received: 21 February 2010 / Revised: 31 March 2010 / Accepted: 6 April 2010 / Published: 12 April 2010
Cited by 10 | PDF Full-text (413 KB) | Supplementary Files
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] [...] 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 Pyridine-Based Heterocycles. Synthesis of New Pyrido [4',3':4,5]thieno[2,3-d]pyrimidines and Related Heterocycles
Molecules 2010, 15(4), 2651-2666; doi:10.3390/molecules15042651
Received: 11 March 2010 / Revised: 31 March 2010 / Accepted: 6 April 2010 / Published: 12 April 2010
Cited by 7 | PDF Full-text (171 KB)
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 [...] 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
Open AccessArticle Access to Original Vinylic Chlorides in the Quinazoline Series via a Monoelectronic Transfer Reaction Approach
Molecules 2010, 15(4), 2719-2729; doi:10.3390/molecules15042719
Received: 26 January 2010 / Revised: 21 February 2010 / Accepted: 12 April 2010 / Published: 13 April 2010
Cited by 4 | PDF Full-text (185 KB)
Abstract A series of new quinazoline derivatives bearing a vinylic chloride group on the 2-position was prepared by using a consecutive SRN1 / ERC1 radical strategy. Full article
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Open AccessArticle MMPBSA Decomposition of the Binding Energy throughout a Molecular Dynamics Simulation of Amyloid-Beta (Aß10−35) Aggregation
Molecules 2010, 15(4), 2730-2748; doi:10.3390/molecules15042730
Received: 13 February 2010 / Revised: 11 March 2010 / Accepted: 19 March 2010 / Published: 15 April 2010
Cited by 13 | PDF Full-text (901 KB)
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 [...] 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 Reactivity Ratios for Organotin Copolymer Systems
Molecules 2010, 15(4), 2749-2758; doi:10.3390/molecules15042749
Received: 18 March 2010 / Revised: 12 April 2010 / Accepted: 13 April 2010 / Published: 15 April 2010
Cited by 3 | PDF Full-text (179 KB)
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 [...] 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
Open AccessArticle A General and Simple Diastereoselective Reduction by L-Selectride: Efficient Synthesis of Protected (4S,5S)-Dihydroxy Amides
Molecules 2010, 15(4), 2771-2781; doi:10.3390/molecules15042771
Received: 18 December 2009 / Revised: 24 March 2010 / Accepted: 12 April 2010 / Published: 16 April 2010
Cited by 2 | PDF Full-text (194 KB)
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 [...] 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)
Open AccessArticle p-Aminoacetophenonic Acids Produced by a Mangrove Endophyte Streptomyces sp. (strain HK10552)
Molecules 2010, 15(4), 2782-2790; doi:10.3390/molecules15042782
Received: 18 March 2010 / Revised: 31 March 2010 / Accepted: 6 April 2010 / Published: 16 April 2010
Cited by 18 | PDF Full-text (234 KB)
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) [...] 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 14 were elucidated by using spectroscopic analyses. The relative stereoconfigurations of compounds 3 and 4 were determined by NOESY experiments. In the bioassay test, 14 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
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
Molecules 2010, 15(4), 2791-2813; doi:10.3390/molecules15042791
Received: 21 February 2010 / Revised: 31 March 2010 / Accepted: 7 April 2010 / Published: 16 April 2010
Cited by 6 | PDF Full-text (890 KB)
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 [...] 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 r2cv 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
Open AccessArticle Neuroprotective Effects of Herbal Ethanol Extracts from Gynostemma pentaphyllum in the 6-Hydroxydopamine-Lesioned Rat Model of Parkinson's Disease
Molecules 2010, 15(4), 2814-2824; doi:10.3390/molecules15042814
Received: 20 February 2010 / Revised: 25 March 2010 / Accepted: 1 April 2010 / Published: 16 April 2010
Cited by 20 | PDF Full-text (1371 KB)
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% [...] 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
Open AccessArticle Cell Proliferation of HaCaT Keratinocytes on Collagen Films Modified by Argon Plasma Treatment
Molecules 2010, 15(4), 2845-2856; doi:10.3390/molecules15042845
Received: 22 January 2010 / Revised: 15 April 2010 / Accepted: 19 April 2010 / Published: 20 April 2010
Cited by 39 | PDF Full-text (2432 KB)
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 [...] 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)
Open AccessArticle Conversion of Aryl Iodides into Aryliodine(III) Dichlorides by an Oxidative Halogenation Strategy Using 30% Aqueous Hydrogen Peroxide in Fluorinated Alcohol
Molecules 2010, 15(4), 2857-2871; doi:10.3390/molecules15042857
Received: 7 January 2010 / Revised: 24 February 2010 / Accepted: 19 March 2010 / Published: 20 April 2010
Cited by 12 | PDF Full-text (419 KB)
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 [...] 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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Open AccessArticle Preparation, Characterization and Adsorption Performance of a Novel Anionic Starch Microsphere
Molecules 2010, 15(4), 2872-2885; doi:10.3390/molecules15042872
Received: 18 March 2010 / Revised: 29 March 2010 / Accepted: 19 April 2010 / Published: 21 April 2010
Cited by 20 | PDF Full-text (712 KB)
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. [...] 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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Open AccessArticle Pharmacogenomic Identification of c-Myc/Max-Regulated Genes Associated with Cytotoxicity of Artesunate towards Human Colon, Ovarian and Lung Cancer Cell Lines
Molecules 2010, 15(4), 2886-2910; doi:10.3390/molecules15042886
Received: 26 March 2010 / Revised: 20 April 2010 / Accepted: 22 April 2010 / Published: 22 April 2010
Cited by 20 | PDF Full-text (624 KB)
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 [...] 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
Open AccessArticle Organic Extractives from Mentha spp. Honey and the Bee-Stomach: Methyl Syringate, Vomifoliol, Terpenediol I, Hotrienol and Other Compounds
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 19 | 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. [...] 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
Open AccessArticle Evaluation of the Antinociceptive Activity and Acute Oral Toxicity of Standardized Ethanolic Extract of the Rhizome of Curcuma xanthorrhiza Roxb
Molecules 2010, 15(4), 2925-2934; doi:10.3390/molecules15042925
Received: 16 January 2010 / Revised: 25 February 2010 / Accepted: 22 March 2010 / Published: 22 April 2010
Cited by 17 | PDF Full-text (400 KB)
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 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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Open AccessReview Norcoclaurine Synthase: Mechanism of an Enantioselective Pictet-Spengler Catalyzing Enzyme
Molecules 2010, 15(4), 2070-2078; doi:10.3390/molecules15042070
Received: 2 March 2010 / Revised: 18 March 2010 / Accepted: 22 March 2010 / Published: 24 March 2010
Cited by 17 | PDF Full-text (135 KB)
Abstract
The use of bifunctional catalysts in organic synthesis finds inspiration in the selectivity of enzymatic catalysis which arises from the specific interactions between basic and acidic amino acid residues and the substrate itself in order to stabilize developing charges in the transition [...] Read more.
The use of bifunctional catalysts in organic synthesis finds inspiration in the selectivity of enzymatic catalysis which arises from the specific interactions between basic and acidic amino acid residues and the substrate itself in order to stabilize developing charges in the transition state. Many enzymes act as bifunctional catalysts using amino acid residues at the active site as Lewis acids and Lewis bases to modify the substrate as required for the given transformation. They bear a clear advantage over non-biological methods for their ability to tackle problems related to the synthesis of enantiopure compounds as chiral building blocks for drugs and agrochemicals. Moreover, enzymatic synthesis may offer the advantage of a clean and green synthetic process in the absence of organic solvents and metal catalysts. In this work the reaction mechanism of norcoclaurine synthase is described. This enzyme catalyzes the Pictet-Spengler condensation of dopamine with 4-hydroxyphenylacetaldehyde (4-HPAA) to yield the benzylisoquinoline alkaloids central precursor, (S)-norcoclaurine. Kinetic and crystallographic data suggest that the reaction mechanism occurs according to a typical bifunctional catalytic process. Full article
(This article belongs to the Special Issue Bifunctional Catalysis)
Open AccessReview An Update on Vitamin E, Tocopherol and Tocotrienol—Perspectives
Molecules 2010, 15(4), 2103-2113; doi:10.3390/molecules15042103
Received: 6 February 2010 / Revised: 15 March 2010 / Accepted: 23 March 2010 / Published: 24 March 2010
Cited by 51 | PDF Full-text (159 KB)
Abstract
Vitamin E, like tocotrienols and tocopherols, is constituted of compounds essential for animal cells. Vitamin E is exclusively synthesized by photosynthetic eukaryotes and other oxygenic photosynthetic organisms such as cyanobacteria. In order to prevent lipid oxidation, the plants mainly accumulate tocochromanols in [...] Read more.
Vitamin E, like tocotrienols and tocopherols, is constituted of compounds essential for animal cells. Vitamin E is exclusively synthesized by photosynthetic eukaryotes and other oxygenic photosynthetic organisms such as cyanobacteria. In order to prevent lipid oxidation, the plants mainly accumulate tocochromanols in oily seeds and fruits or in young tissues undergoing active cell divisions. From a health point of view, at the moment there is a great interest in the natural forms of tocochromanols, because they are considered promising compounds able to maintain a healthy cardiovascular system and satisfactory blood cholesterol levels. Some evidence suggests that the potency of the antioxidant effects may differ between natural or synthetic source of tocochromanols (vitamin E). Full article
(This article belongs to the Special Issue Vitamins)
Open AccessReview Recent Advances in Noble Metal Nanocatalysts for Suzuki and Heck Cross-Coupling Reactions
Molecules 2010, 15(4), 2124-2138; doi:10.3390/molecules15042124
Received: 12 January 2010 / Revised: 2 March 2010 / Accepted: 23 March 2010 / Published: 25 March 2010
Cited by 88 | PDF Full-text (1245 KB)
Abstract
Since metal nanoparticles have a high surface-to-volume ratio and very active surface atoms, they are very attractive catalysts for a wide variety of organic and inorganic reactions, compared to bulk catalysts. Metal nanoparticles suspended in colloidal solutions and those adsorbed onto bulk [...] Read more.
Since metal nanoparticles have a high surface-to-volume ratio and very active surface atoms, they are very attractive catalysts for a wide variety of organic and inorganic reactions, compared to bulk catalysts. Metal nanoparticles suspended in colloidal solutions and those adsorbed onto bulk supports have been used as catalysts for a wide variety of carbon-carbon bond formation reactions such as the Suzuki and Heck cross-coupling reactions. This review article highlights some of the latest advances in the application of noble metal nanoparticles as catalysts for these two industrially important classes of cross-coupling reactions. We will discuss several important advances in using metal nanocatalysts in Suzuki and Heck cross-coupling reactions such as investigations on the nanoparticle shape dependence on the catalytic activity, novel types of supported metal nanoparticles as nanocatalysts, and the use of bi-metallic, tri-metallic and multi-metallic nanoparticles as catalysts for the Suzuki and Heck cross-coupling reactions. Full article
(This article belongs to the Special Issue Nano-catalysts and Nano-technologies for Green Organic Synthesis)
Open AccessReview The Heck Reaction in Ionic Liquids: Progress and Challenges
Molecules 2010, 15(4), 2211-2245; doi:10.3390/molecules15042211
Received: 3 March 2010 / Revised: 22 March 2010 / Accepted: 26 March 2010 / Published: 30 March 2010
Cited by 52 | PDF Full-text (1077 KB)
Abstract
As the interest for environmental increases and environmental laws become more stringent, the need to replace existing processes with new more sustainable technologies becomes a primary objective. The use of ionic liquids to replace organic solvents in metal catalyzed reactions has recently [...] Read more.
As the interest for environmental increases and environmental laws become more stringent, the need to replace existing processes with new more sustainable technologies becomes a primary objective. The use of ionic liquids to replace organic solvents in metal catalyzed reactions has recently gained much attention and great progress has been accomplished in this area in the last years. This paper reviews the recent developments in the application of ionic liquids and related systems (supported ionic liquids, ionic polymers, and so on) in the Heck reaction. Merits and achievements of ionic liquids were analyzed and discussed considering the possibility of increasing the effectiveness of industrial processes. Full article
(This article belongs to the Special Issue Heck Coupling)
Open AccessReview Recent Applications of Ionic Liquids in Separation Technology
Molecules 2010, 15(4), 2405-2426; doi:10.3390/molecules15042405
Received: 4 March 2010 / Revised: 29 March 2010 / Accepted: 2 April 2010 / Published: 5 April 2010
Cited by 192 | PDF Full-text (345 KB)
Abstract
Ionic liquids (ILs) have been applied in different areas of separation, such as ionic liquid supported membranes, as mobile phase additives and surface-bonded stationary phases in chromatography separations and as the extraction solvent in sample preparations, because they can be composed from [...] Read more.
Ionic liquids (ILs) have been applied in different areas of separation, such as ionic liquid supported membranes, as mobile phase additives and surface-bonded stationary phases in chromatography separations and as the extraction solvent in sample preparations, because they can be composed from various cations and anions that change the properties and phase behavior of liquids. Although the applications of ILs in separations are still in their early stages, the academic interest in ILs is increasing. An overview of the principle applications of ILs in separation technology is present in this work. Furthermore, the prospects of the ILs in separation techniques are discussed. Full article
(This article belongs to the Special Issue Ionic Liquids)
Open AccessReview Automation in the High-throughput Selection of Random Combinatorial Libraries—Different Approaches for Select Applications
Molecules 2010, 15(4), 2478-2490; doi:10.3390/molecules15042478
Received: 10 February 2010 / Revised: 30 March 2010 / Accepted: 6 April 2010 / Published: 8 April 2010
Cited by 12 | PDF Full-text (279 KB)
Abstract
Automation in combination with high throughput screening methods has revolutionised molecular biology in the last two decades. Today, many combinatorial libraries as well as several systems for automation are available. Depending on scope, budget and time, a different combination of library and [...] Read more.
Automation in combination with high throughput screening methods has revolutionised molecular biology in the last two decades. Today, many combinatorial libraries as well as several systems for automation are available. Depending on scope, budget and time, a different combination of library and experimental handling might be most effective. In this review we will discuss several concepts of combinatorial libraries and provide information as what to expect from these depending on the given context. Full article
(This article belongs to the Special Issue High-throughput Screening)
Open AccessReview The Heck Reaction Applied to 1,3- and 1,2-Unsaturated Derivatives, a Way towards Molecular Complexity
Molecules 2010, 15(4), 2667-2685; doi:10.3390/molecules15042667
Received: 1 February 2010 / Revised: 26 March 2010 / Accepted: 1 April 2010 / Published: 13 April 2010
Cited by 35 | PDF Full-text (378 KB)
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 [...] 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)
Open AccessReview Iodine-124: A Promising Positron Emitter for Organic PET Chemistry
Molecules 2010, 15(4), 2686-2718; doi:10.3390/molecules15042686
Received: 5 March 2010 / Revised: 7 April 2010 / Accepted: 9 April 2010 / Published: 13 April 2010
Cited by 41 | PDF Full-text (779 KB)
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 [...] 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, t1/2 = 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)
Open AccessReview Essential Oil of Myrtus communis L. as a Potential Antioxidant and Antimutagenic Agents
Molecules 2010, 15(4), 2759-2770; doi:10.3390/molecules15042759
Received: 20 January 2010 / Revised: 9 February 2010 / Accepted: 1 March 2010 / Published: 15 April 2010
Cited by 48 | PDF Full-text (193 KB)
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 [...] 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
Open AccessReview µ-Conotoxins as Leads in the Development of New Analgesics
Molecules 2010, 15(4), 2825-2844; doi:10.3390/molecules15042825
Received: 9 March 2010 / Revised: 6 April 2010 / Accepted: 12 April 2010 / Published: 19 April 2010
Cited by 32 | PDF Full-text (503 KB)
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 [...] 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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