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Molecules, Volume 16, Issue 4 (April 2011) – 53 articles , Pages 2743-3455

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Open AccessArticle
Antioxidant Compounds from Propolis Collected in Anhui, China
Molecules 2011, 16(4), 3444-3455; https://doi.org/10.3390/molecules16043444 - 21 Apr 2011
Cited by 90 | Viewed by 7720
Abstract
The antioxidant activities of the chloroform, ethyl acetate and n-butanol extract fractions from propolis collected in Anhui, China were evaluated in this study. The ethyl acetate fraction contained the highest amount of total phenolics and total flavonoids, and showed the greatest 1,1-diphenyl-2-picrylhydrazyl [...] Read more.
The antioxidant activities of the chloroform, ethyl acetate and n-butanol extract fractions from propolis collected in Anhui, China were evaluated in this study. The ethyl acetate fraction contained the highest amount of total phenolics and total flavonoids, and showed the greatest 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging capacities and Ferric Reducing/Antioxidant Power (FRAP). The antioxidant activity of twenty-two compounds isolated from the ethyl acetate fraction was also evaluated using the above-mentioned three assays. The results indicated that phenolics contributed to the antioxidant activity of propolis collected in Anhui, China. Therefore, propolis collected in Anhui, China and its phenolics might be used as a natural antioxidant. Full article
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Open AccessArticle
Antioxidant, Total Phenolic Content and Cytotoxicity Evaluation of Selected Malaysian Plants
Molecules 2011, 16(4), 3433-3443; https://doi.org/10.3390/molecules16043433 - 21 Apr 2011
Cited by 112 | Viewed by 11286
Abstract
Aqueous and ethanol extracts of different traditional Malaysian plants (Polygonum minus, Andrographis paniculata, Curcuma xanthorrhiza, Momordica charantia and Strobilanthes crispus) were evaluated for their antioxidant properties, total phenolic content and cytotoxic activity. Antioxidant activity was evaluated by using 1,1-diphenyl-1-picrylhydrazyl (DPPH) [...] Read more.
Aqueous and ethanol extracts of different traditional Malaysian plants (Polygonum minus, Andrographis paniculata, Curcuma xanthorrhiza, Momordica charantia and Strobilanthes crispus) were evaluated for their antioxidant properties, total phenolic content and cytotoxic activity. Antioxidant activity was evaluated by using 1,1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The results showed that ethanol extracts contain high antioxidant activities compared to aqueous extracts. The findings exhibited a strong correlation between antioxidant activity and the total phenol contents. In addition, all the plant extracts showed non-toxic effects against a normal human lung fibroblast cell line (Hs888Lu). Although traditionally aqueous extracts are used, we determined that ethanol extracts usually achieved better activity in the assays. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle
Proline-Catalysed Amination Reactions in Cyclic Carbonate Solvents
Molecules 2011, 16(4), 3420-3432; https://doi.org/10.3390/molecules16043420 - 21 Apr 2011
Cited by 50 | Viewed by 4470
Abstract
Propylene carbonate is shown to be an environmentally friendly and sustainable replacement for dichloromethane and acetonitrile in proline-catalysed a-hydrazinations of aldehydes and ketones. Enantioselectivities comparable to those obtained in conventional solvents or ionic liquids can be obtained, even when using a lower catalyst [...] Read more.
Propylene carbonate is shown to be an environmentally friendly and sustainable replacement for dichloromethane and acetonitrile in proline-catalysed a-hydrazinations of aldehydes and ketones. Enantioselectivities comparable to those obtained in conventional solvents or ionic liquids can be obtained, even when using a lower catalyst loading. Full article
(This article belongs to the Special Issue Catalytic Asymmetric Synthesis)
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Open AccessArticle
Synthesis and Anticancer Activity of Some Novel Tetralin-6-yl-pyrazoline, 2-Thioxopyrimidine, 2-Oxopyridine, 2-Thioxo-pyridine and 2-Iminopyridine Derivatives
Molecules 2011, 16(4), 3410-3419; https://doi.org/10.3390/molecules16043410 - 20 Apr 2011
Cited by 39 | Viewed by 6332
Abstract
The title compounds were prepared by reaction of 6-acetyltetralin (1) with different aromatic aldehydes 2a-c, namely 2,6-dichlorobenzaldehyde, 2,6-diflouro-benzaldehyde, and 3-ethoxy-4-hydroxybenzaldehyde, to yield the corresponding a,b-unsaturated ketones 3a-c. Compound 3b was reacted with hydrazine hydrate to yield the corresponding 2-pyrazoline 4 [...] Read more.
The title compounds were prepared by reaction of 6-acetyltetralin (1) with different aromatic aldehydes 2a-c, namely 2,6-dichlorobenzaldehyde, 2,6-diflouro-benzaldehyde, and 3-ethoxy-4-hydroxybenzaldehyde, to yield the corresponding a,b-unsaturated ketones 3a-c. Compound 3b was reacted with hydrazine hydrate to yield the corresponding 2-pyrazoline 4, while compounds 3a,b reacted with thiourea to afford the 2-thioxopyrimidine derivatives 5a,b, respectively. The reaction of 1, and the aromatic aldehydes 2a-c with ethyl cyanoacetate, 2-cyano-thioacetamide or malononitrile in the presence of ammonium acetate yielded the corresponding 2-oxopyridines 6a,b, 2-thioxopyridines 7a-c or 2-iminopyridines 8a,b, respectively. The newly prepared compounds were evaluated for anticancer activity against two human tumor cell lines. Compound 3a showed the highest potency with IC50 = 3.5 and 4.5 μg/mL against a cervix carcinoma cell line (Hela) and breast carcinoma cell line (MCF7), respectively. Full article
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Open AccessArticle
N-Cyanomethylnorboldine: A New Aporphine Isolated from Alseodaphne perakensis (Lauraceae)
Molecules 2011, 16(4), 3402-3409; https://doi.org/10.3390/molecules16043402 - 20 Apr 2011
Cited by 8 | Viewed by 5250
Abstract
A phytochemical study of the bark of Alseodaphne perakensis has yielded three aporphine alkaloids: the new compound N-cyanomethylnorboldine (1), and the two known alkaloids N-methyllaurotetanine (2) and norboldine (3). The isolation was achieved by [...] Read more.
A phytochemical study of the bark of Alseodaphne perakensis has yielded three aporphine alkaloids: the new compound N-cyanomethylnorboldine (1), and the two known alkaloids N-methyllaurotetanine (2) and norboldine (3). The isolation was achieved by chromatographic techniques and the structural elucidation was performed via spectral methods, notably 1D- and 2D-NMR, UV, IR, and HRFABMS. The vasorelaxation activity of compound 1 has been studied. Full article
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Open AccessArticle
Seasonal Variation of Bioactive Alkaloid Contents in Macleaya microcarpa (Maxim.) Fedde
Molecules 2011, 16(4), 3391-3401; https://doi.org/10.3390/molecules16043391 - 20 Apr 2011
Cited by 22 | Viewed by 5555
Abstract
Macleaya microcarpa (Maxim.) Fedde belongs to the genus Macleaya, family Papaveraceae. Together with the better known and more frequently studied species M. cordata (Willd.) R. Br. it is a main source of quaternary benzo[c]phenanthridine alkaloids. Using HPLC we determined the content [...] Read more.
Macleaya microcarpa (Maxim.) Fedde belongs to the genus Macleaya, family Papaveraceae. Together with the better known and more frequently studied species M. cordata (Willd.) R. Br. it is a main source of quaternary benzo[c]phenanthridine alkaloids. Using HPLC we determined the content of eight isoquinoline alkaloids in the aerial and underground parts of 1-, 2-, 12- and 13-year old plants and followed their changes during the vegetative period. The dominant alkaloid of all samples collected in the end of this period was allocryptopine (3.8–13.6 mg/g for aerial parts, 24.2–48.9 mg/g for underground parts). Chelerythrine, sanguinarine and protopine were also present in both parts of the plant. Additionally, measurable concentrations of chelilutine (CL), chelirubine (CR), macarpine (MA) and sanguirubine (SR) were detected in underground parts. The most important finding was that contents of CR, CL, SR and MA in the 12- and 13-year old plant roots were significantly higher (approximately 3-fold for CR, 6-fold for CL, 5-fold for SR, and at least 14-fold for MA) than in 1- or 2-year old plants. The proportion of individual alkaloids in aerial and underground parts thus changed significantly during the vegetative period. Full article
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Open AccessArticle
Simple and Efficient Synthesis of Racemic 2-(tert-Butoxycarbon-ylamino)-2-methyl-3-(1H-1,2,4-triazol-1-yl)propanoic Acid, a New Derivative of β-(1,2,4-Triazol-1-yl)alanine
Molecules 2011, 16(4), 3380-3390; https://doi.org/10.3390/molecules16043380 - 19 Apr 2011
Cited by 3 | Viewed by 6541
Abstract
A simple synthetic approach to racemic N-tert-butyloxycarbonyl-2-methyl-3-(1H-1,2,4-triazol-1-yl)alanine (5) in four steps and 68% overall yield starting from oxazoline derivative 1 is reported. This synthesis involves the alkylation of 1H-1,2,4-triazole with an O-tosyloxazoline derivative, [...] Read more.
A simple synthetic approach to racemic N-tert-butyloxycarbonyl-2-methyl-3-(1H-1,2,4-triazol-1-yl)alanine (5) in four steps and 68% overall yield starting from oxazoline derivative 1 is reported. This synthesis involves the alkylation of 1H-1,2,4-triazole with an O-tosyloxazoline derivative, followed by an oxazoline ring-opening reaction and oxidation of the N-protected β‑aminoalcohol by potassium permanganate. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle
Salidroside Attenuates Hydrogen Peroxide-Induced Cell Damage Through a cAMP-Dependent Pathway
Molecules 2011, 16(4), 3371-3379; https://doi.org/10.3390/molecules16043371 - 19 Apr 2011
Cited by 12 | Viewed by 7310
Abstract
Salidroside, a major component of Rhodiola rosea L., has shown various pharmacological functions, including antioxidant effects, but the signal transduction pathway of its antioxidant effects is not very clear. In this study, we found that salidroside could attenuate hydrogen peroxide (H [...] Read more.
Salidroside, a major component of Rhodiola rosea L., has shown various pharmacological functions, including antioxidant effects, but the signal transduction pathway of its antioxidant effects is not very clear. In this study, we found that salidroside could attenuate hydrogen peroxide (H2O2)-induced HL-7702 cell damage, inhibit H2O2-induced cytosolic free Ca2+ ([Ca2+]i) elevation, scavenge reactive oxygen species (ROS) and increase 3’-5’-cyclic adenosine monophosphate (cAMP) level in a dose-dependent manner, but it couldn’t influence 3’-5’-cyclic guanosine monophosphate (cGMP) levels. Therefore, these results indicated that the antioxidant effects of salidroside were associated with down-regulation of [Ca2+]i, ROS occur via a cAMP-dependent pathway. Full article
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Open AccessArticle
Antitussive Activity of Pseudostellaria heterophylla (Miq.) Pax Extracts and Improvement in Lung Function via Adjustment of Multi-Cytokine Levels
Molecules 2011, 16(4), 3360-3370; https://doi.org/10.3390/molecules16043360 - 19 Apr 2011
Cited by 26 | Viewed by 5237
Abstract
Pseudostellaria heterophylla (Miq.) Pax is one of the most widespread herbal and healthcare products in China. Extensive clinical use has shown that it has functions which “strengthens qi and generates saliva, moistens the lung and relieves cough”. The ethyl acetate fraction extracted from [...] Read more.
Pseudostellaria heterophylla (Miq.) Pax is one of the most widespread herbal and healthcare products in China. Extensive clinical use has shown that it has functions which “strengthens qi and generates saliva, moistens the lung and relieves cough”. The ethyl acetate fraction extracted from the roots of the plant Pseudostellaria heterophylla exhibited a dose-dependent antitussive effect between 100 to 500 mg/kg. At a dose of 400 mg/kg, the ethyl acetate fraction treatment markedly prolonged the cough latent period and reduced the number of coughs in a guinea pig model induced by citric acid. Fall lung airway resistance, rise in dynamic lung compliance, decreased serum levels of IL-8, GM-CSF, TNF-α, and ET-1 in rat model of stable phase chronic obstructive pulmonary disease induced by cigarette smoke exposure were also observed. These results suggest that ethyl acetate fraction has antitussive activity related to its improvement in lung function via attenuation of airway inflammation by adjustment of multi-cytokine levels. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle
Three New Oblongolides from Phomopsis sp. XZ-01, an Endophytic Fungus from Camptotheca acuminate
Molecules 2011, 16(4), 3351-3359; https://doi.org/10.3390/molecules16043351 - 19 Apr 2011
Cited by 9 | Viewed by 6947
Abstract
Four new metabolites, including three new oblongolides named C1, P1, and X1 (1-3) and 6-hydroxyphomodiol (10), along with eight known compounds – oblongolides B (4), C (5), D (6), O ( [...] Read more.
Four new metabolites, including three new oblongolides named C1, P1, and X1 (1-3) and 6-hydroxyphomodiol (10), along with eight known compounds – oblongolides B (4), C (5), D (6), O (7), P (8) and U (9), (3R,4aR,5S,6R)-6-hydroxy-5-methylramulosin (11), and (3R)-5-methylmellein (12) – were isolated from the endophytic fungal strain Phomopsis sp. XZ-01 of Camptotheca acuminate. Their structures were elucidated by spectroscopic analyses, including 1H- and 13C-NMR, 2D NMR (HSQC, HMBC, 1H-1H COSY and NOESY) and HR-FT-MS. Cytotoxic activities of these compounds were evaluated. Some of them showed weak selective activities. Full article
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Open AccessArticle
Identification of Diterpenoid Alkaloids from the Roots of Aconitum kusnezoffii Reihcb.
Molecules 2011, 16(4), 3345-3350; https://doi.org/10.3390/molecules16043345 - 19 Apr 2011
Cited by 14 | Viewed by 5737
Abstract
Three diterpenoid alkaloids, including an unreported compound, were isolated from the roots of Aconitum kusnezoffii Reichb. On the basis of spectral analysis, these three compounds were determined to be 1,15-dimethoxy-3-hydroxy-14-benzoyl-16-ketoneoline, benzoylaconine and aconitine. Full article
(This article belongs to the Special Issue Alkaloids: Novel Therapeutic Perspectives)
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Open AccessArticle
Kaempferol and Kaempferol Rhamnosides with Depigmenting and Anti-Inflammatory Properties
Molecules 2011, 16(4), 3338-3344; https://doi.org/10.3390/molecules16043338 - 18 Apr 2011
Cited by 46 | Viewed by 6524
Abstract
The objective of this study was to examine the biological activity of kaempferol and its rhamnosides. We isolated kaempferol (1), a-rhamnoisorobin (2), afzelin (3), and kaempferitrin (4) as pure compounds by far-infrared (FIR) irradiation of [...] Read more.
The objective of this study was to examine the biological activity of kaempferol and its rhamnosides. We isolated kaempferol (1), a-rhamnoisorobin (2), afzelin (3), and kaempferitrin (4) as pure compounds by far-infrared (FIR) irradiation of kenaf (Hibiscus cannabinus L.) leaves. The depigmenting and anti-inflammatory activity of the compounds was evaluated by analyzing their structure-activity relationships. The order of the inhibitory activity with regard to depigmentation and nitric oxide (NO) production was kaempferol (1) > a-rhamnoisorobin (2) > afzelin (3) > kaempferitrin (4). However, a-rhamnoisorobin (2) was more potent than kaempferol (1) in NF-kB-mediated luciferase assays. From these results, we conclude that the 3-hydroxyl group of kaempferol is an important pharmacophore and that additional rhamnose moieties affect the biological activity negatively. Full article
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Open AccessReview
Two-Photon Polarization Dependent Spectroscopy in Chirality: A Novel Experimental-Theoretical Approach to Study Optically Active Systems
Molecules 2011, 16(4), 3315-3337; https://doi.org/10.3390/molecules16043315 - 18 Apr 2011
Cited by 18 | Viewed by 9455
Abstract
Many phenomena, including life itself and its biochemical foundations are fundamentally rooted in chirality. Combinatorial methodologies for catalyst discovery and optimization remain an invaluable tool for gaining access to enantiomerically pure compounds in the development of pharmaceuticals, agrochemicals, and flavors. Some exotic metamaterials [...] Read more.
Many phenomena, including life itself and its biochemical foundations are fundamentally rooted in chirality. Combinatorial methodologies for catalyst discovery and optimization remain an invaluable tool for gaining access to enantiomerically pure compounds in the development of pharmaceuticals, agrochemicals, and flavors. Some exotic metamaterials exhibiting negative refractive index at optical frequencies are based on chiral structures. Chiroptical activity is commonly quantified in terms of circular dichroism (CD) and optical rotatory dispersion (ORD). However, the linear nature of these effects limits their application in the far and near-UV region in highly absorbing and scattering biological systems. In order to surmount this barrier, in recent years we made important advancements on a novel non linear, low-scatter, long-wavelength CD approach called two-photon absorption circular dichroism (TPACD). Herein we present a descriptive analysis of the optics principles behind the experimental measurement of TPACD, i.e., the double L-scan technique, and its significance using pulsed lasers. We also make an instructive examination and discuss the reliability of our theoretical-computational approach, which uses modern analytical response theory, within a Time-Dependent Density Functional Theory (TD-DFT) approach. In order to illustrate the potential of this novel spectroscopic tool, we first present the experimental and theoretical results obtained in C2-symmetric, axially chiral R-(+)-1,1'-bi(2-naphthol), R-BINOL, a molecule studied at the beginning of our investigation in this field. Next, we reveal some preliminary results obtained for (R)-3,3′-diphenyl-2,2′-bi-1-naphthol, R-VANOL, and (R)-2,2′-diphenyl-3,3′-(4-biphenanthrol), R-VAPOL. This family of optically active compounds has been proven to be a suitable model for the structure-property relationship study of TPACD, because its members are highly conjugated yet photo-stable, and easily derivatized at the 5- and 6-positions. With the publication of these outcomes we hope to motivate more members of the scientist community to engage in state-of-the-art TPACD spectroscopy. Full article
(This article belongs to the Special Issue Chiroptical Techniques)
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Open AccessReview
From Polymer to Small Organic Molecules: A Tight Relationship between Radical Chemistry and Solid-Phase Organic Synthesis
Molecules 2011, 16(4), 3252-3314; https://doi.org/10.3390/molecules16043252 - 18 Apr 2011
Cited by 9 | Viewed by 6332
Abstract
Since Gomberg’s discovery of radicals as chemical entities, the interest around them has increased through the years. Nowadays, radical chemistry is used in the synthesis of 75% of all polymers, inevitably establishing a close relationship with Solid-Phase Organic Synthesis. More recently, the interest [...] Read more.
Since Gomberg’s discovery of radicals as chemical entities, the interest around them has increased through the years. Nowadays, radical chemistry is used in the synthesis of 75% of all polymers, inevitably establishing a close relationship with Solid-Phase Organic Synthesis. More recently, the interest of organic chemists has shifted towards the application of usual “in-solution” radical chemistry to the solid-phase, ranging from the use of supported reagents for radical reactions, to the development of methodologies for the synthesis of small molecules or potential libraries. The aim of this review is to put in perspective radical chemistry, moving it away from its origin as a synthetic means for solid supports, to becoming a useful tool for the synthesis of small molecules. Full article
(This article belongs to the Special Issue Diversity Oriented Synthesis)
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Open AccessReview
Selenol Protecting Groups in Organic Chemistry: Special Emphasis on Selenocysteine Se-Protection in Solid Phase Peptide Synthesis
Molecules 2011, 16(4), 3232-3251; https://doi.org/10.3390/molecules16043232 - 18 Apr 2011
Cited by 21 | Viewed by 8244
Abstract
The appearance of selenium in organic synthesis is relatively rare, and thus examples in the literature pertaining to the masking of its considerable reactivity are similarly uncommon. Greene's Protecting Groups in Organic Synthesis, the standard reference for the state of the art in [...] Read more.
The appearance of selenium in organic synthesis is relatively rare, and thus examples in the literature pertaining to the masking of its considerable reactivity are similarly uncommon. Greene's Protecting Groups in Organic Synthesis, the standard reference for the state of the art in this arena, offers no entries for selenium protective methodology, in stark comparison to its mention of the great variety of protecting groups germane to its chalcogen cousin sulfur. This scarcity of Se-protection methods makes it no less interesting and pertinent toward the construction of selenium-containing organic systems which do indeed require the iterative blocking and de-blocking of selenol functionalities. A selenium-containing system which is especially relevant is selenocysteine, as its use in Solid Phase Peptide Synthesis requires extensive protection of its selenol side chain. This review will attempt to summarize the current state of understanding with regard to selenium protection protocol in organic synthesis. Moreover, it will provide a special emphasis on selenocysteine side chain protection, comprising both the breadth of functionality used for this purpose as well as methods of deprotection. Full article
(This article belongs to the Special Issue Protecting Group in Organic Synthesis)
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Open AccessArticle
Structure Identification of Euphorbia Factor L3 and Its Induction of Apoptosis through the Mitochondrial Pathway
Molecules 2011, 16(4), 3222-3231; https://doi.org/10.3390/molecules16043222 - 15 Apr 2011
Cited by 13 | Viewed by 5781
Abstract
In this article, we have focused on the structure identification of Euphorbia factor L3 belonging to the lathyrane diterpenoids isolated from Caper Euphorbia Seed. Its anticancer activity in vitro against lung cancer A549 cells was also investigated and the IC50 values were [...] Read more.
In this article, we have focused on the structure identification of Euphorbia factor L3 belonging to the lathyrane diterpenoids isolated from Caper Euphorbia Seed. Its anticancer activity in vitro against lung cancer A549 cells was also investigated and the IC50 values were 34.04 ± 3.99 μM. Furthermore, Euphorbia factor L3 could induce apoptosis in A549 cells via the mitochondrial pathway including loss of mitochondrial potential and release of cytochrome c. Full article
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Open AccessArticle
Kazinol Q from Broussonetia kazinoki Enhances Cell Death Induced by Cu(ll) through Increased Reactive Oxygen Species
Molecules 2011, 16(4), 3212-3221; https://doi.org/10.3390/molecules16043212 - 15 Apr 2011
Cited by 9 | Viewed by 5398
Abstract
The ability of the flavan kazinol Q (KQ) to induce DNA breakage in the presence of Cu(II) was examined by agarose gel electrophoresis using supercoiled plasmid DNA. In KQ-mediated DNA breakage reaction, the involvement of reactive oxygen species (ROS), H [...] Read more.
The ability of the flavan kazinol Q (KQ) to induce DNA breakage in the presence of Cu(II) was examined by agarose gel electrophoresis using supercoiled plasmid DNA. In KQ-mediated DNA breakage reaction, the involvement of reactive oxygen species (ROS), H2O2 and O2 - was established by the inhibition of DNA breakage by catalase and revealed DNA breakage by superoxide dismutase (SOD). The cell viability of gastric carcinoma SCM-1 cells treated with various concentrations of KQ was significantly decreased by cotreatment with Cu(II). Treatment of SCM-1 cells with 300 μM Cu(II) enhanced the necrosis induced by 100 μM KQ. Treatment of SCM-1 cells with 100 mM KQ in the presence of 300 mM Cu(II) increased the generation of H2O2. Taken together, the above finding suggested that KQ cotreatment with Cu(II) produced increased amounts of H2O2, thus enhancing subsequent cell death due to necrosis. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle
Antioxidant Properties and Antioxidant Compounds of Various Extracts from the Edible Basidiomycete Grifola Frondosa (Maitake)
Molecules 2011, 16(4), 3197-3211; https://doi.org/10.3390/molecules16043197 - 15 Apr 2011
Cited by 62 | Viewed by 9134
Abstract
Grifola frondosa is an edible mushroom currently available in Taiwan. Ethanolic, cold-water and hot-water extracts were prepared and their antioxidant properties were investigated. At 1 mg/mL, G. frondosa T1 and T2 cold-water extracts showed high reducing powers of 1.02 and 0.50, respectively. Chelating [...] Read more.
Grifola frondosa is an edible mushroom currently available in Taiwan. Ethanolic, cold-water and hot-water extracts were prepared and their antioxidant properties were investigated. At 1 mg/mL, G. frondosa T1 and T2 cold-water extracts showed high reducing powers of 1.02 and 0.50, respectively. Chelating abilities on ferrous ions of G. frondosa T1 and T2 were higher for cold-water extracts than for ethanolic and hot-water extracts. For the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, G. frondosa T1 and T2 extracts were effective in the following order: ethanolic > hot-water > cold-water. The G. frondosa hot-water extract showed high scavenging ability on superoxide anions. Total phenols, flavonoids, ascorbic acid and α-tocopherol are the major antioxidant components found in the various G. frondosa extracts. Based on EC50 values ( Full article
(This article belongs to the Special Issue Antioxidants)
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Open AccessArticle
Induction of Intracellular Ca2+ and pH Changes in Sf9 Insect Cells by Rhodojaponin-III, A Natural Botanic Insecticide Isolated from Rhododendron molle
Molecules 2011, 16(4), 3179-3196; https://doi.org/10.3390/molecules16043179 - 15 Apr 2011
Cited by 8 | Viewed by 7664
Abstract
Many studies on intracellular calcium ([Ca2+]i) and intracellular pH (pHi) have been carried out due to their importance in regulation of different cellular functions. However, most of the previous studies are focused on human or mammalian cells. [...] Read more.
Many studies on intracellular calcium ([Ca2+]i) and intracellular pH (pHi) have been carried out due to their importance in regulation of different cellular functions. However, most of the previous studies are focused on human or mammalian cells. The purpose of the present study was to characterize the effect of Rhodojaponin-III (R-III) on [Ca2+]i and pHi and the proliferation of Sf9 cells. R-III strongly inhibited Sf9 cells proliferation with a time- and dose-dependent manner. Flow cytometry established that R-III interfered with Sf9 cells division and arrested them in G2/M. By using confocal scanning technique, effects of R-III on intracellular free calcium ([Ca2+]i) and intracellular pH (pHi) in Sf9 cells were determined. R-III induced a significant dose-dependent (1, 10, 100, 200 μg/mL) increase in [Ca2+]i and pHi of Sf9 cells in presence of Ca2+-containing solution (Hanks) and an irreversible decrease in the absence of extra cellular Ca2+. We also found that both extra cellular Ca2+ and intracellular Ca2+ stores contributed to the increase of [Ca2+]i, because completely treating Sf9 cells with CdCl2 (5 mM), a Ca2+ channels blocker, R-III (100 μg/mL) induced a transient elevation of [Ca2+]i in case of cells either in presence of Ca2+ containing or Ca2+ free solution. In these conditions, pHi showed similar changes with that of [Ca2+]i on the whole. Accordingly, we supposed that there was a certain linkage for change of [Ca2+]i, cell cycle arrest, proliferation inhibition in Sf9 cells induced by R-III. Full article
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Open AccessArticle
Syntheses, Structures and Antimicrobial Activities of bis(Imino)acenaphthene (BIAN) Imidazolium Salts
Molecules 2011, 16(4), 3168-3178; https://doi.org/10.3390/molecules16043168 - 15 Apr 2011
Cited by 14 | Viewed by 7226
Abstract
The syntheses of four new bis(imino)acenaphthene (BIAN) imidazolium chlorides are reported, three of which have been structurally characterized. The synthesis of a new, structurally authenticated BIAN ligand is also described. We report the results of the use of these BIAN imidazolium salts as [...] Read more.
The syntheses of four new bis(imino)acenaphthene (BIAN) imidazolium chlorides are reported, three of which have been structurally characterized. The synthesis of a new, structurally authenticated BIAN ligand is also described. We report the results of the use of these BIAN imidazolium salts as antimicrobials against the pathogens S. aureus, B. subtilis, E. coli and P. aeruginosa. The antimicrobial efficacies were particularly high for the N-(2,6-diisopropylphenyl)- and N-(mesityl)- substituted BIAN imidazolium salts (MIC values < 0.6 μg/mL). Full article
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Open AccessArticle
Antioxidant Activities of Melittis melissophyllum L. (Lamiaceae)
Molecules 2011, 16(4), 3152-3167; https://doi.org/10.3390/molecules16043152 - 14 Apr 2011
Cited by 10 | Viewed by 5126
Abstract
Extracts of Melittis melissophyllum leaves in ether, chloroform, ethyl acetate, n-butanol and water were evaporated to dryness and dissolved in 50% ethanol to make 10% (w/v) solutions. The potential protective action of the extracts was assessed by the corresponding in vitro and [...] Read more.
Extracts of Melittis melissophyllum leaves in ether, chloroform, ethyl acetate, n-butanol and water were evaporated to dryness and dissolved in 50% ethanol to make 10% (w/v) solutions. The potential protective action of the extracts was assessed by the corresponding in vitro and in vivo tests. In the in vitro experiments extracts were tested as potential scavengers of free radicals (DPPH, O2·-, NO, and OH radicals), as well as inhibitors of liposomal peroxidation (LPx). The results obtained show that all extracts (exept n-BuOH extract) are good scavengers of radicals and reduce LPx intensity in liposomes, which points to their protective (antioxidant) activity. In vivo experiments were concerned with antioxidant systems (activities of GSHPx, GSHR, Px, CAT, XOD, GSH content and intensity of LPx) in liver homogenate and blood-hemolysate of experimental animals after their treatment with extracts of M. melissophyllum leaves, or in combination with CCl4. On the basis of the results obtained it can be concluded that the examined extracts have protective (antioxidative) effect and this antioxidative behaviour is more pronounced in liver than in blood-hemolysate. The reason is probably the fact that liver contains other enzymatic systems, which can also participate in the antioxidative mechanism. Of all the extracts the H2O one showed the highest protective activity. Full article
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Open AccessCommunication
Screening for Compounds with Aromatase Inhibiting Activities from Atractylodes macrocephala Koidz
Molecules 2011, 16(4), 3146-3151; https://doi.org/10.3390/molecules16043146 - 14 Apr 2011
Cited by 33 | Viewed by 6277
Abstract
Ten compounds were isolated from the dichloromethane extract of Atractylodes macrocephala and their aromatase inhibiting activities were tested using an in vitro fluorescent-based aromatase assay. The results indicated that atractylenolide I (1), atractylenolide II (2) and atractylenolide III ( [...] Read more.
Ten compounds were isolated from the dichloromethane extract of Atractylodes macrocephala and their aromatase inhibiting activities were tested using an in vitro fluorescent-based aromatase assay. The results indicated that atractylenolide I (1), atractylenolide II (2) and atractylenolide III (3) had inhibition ratios of 94.56 ± 0.70%, 90.93 ± 1.41% and 86.31 ± 8.46%, respectively, at a concentration of 10 μM. We conclude from our results that atractylenolide and its derivates may serve as potential aromatase inhibitors (AIs) and thus merit continued study in the future. Full article
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Open AccessArticle
On the Reducible Character of Haldane-Radić Enzyme Kinetics to Conventional and Logistic Michaelis-Menten Models
Molecules 2011, 16(4), 3128-3145; https://doi.org/10.3390/molecules16043128 - 13 Apr 2011
Cited by 11 | Viewed by 6733
Abstract
The conceptual and practical issues regarding the reduction of the Haldane-Radić enzymic mechanism, specific for cholinesterase kinetics, to the consecrated or logistically modified Michaelis-Menten kinetics, specific for some mutant enzymes, are here clarified as due to the limited initial substrate concentration, through detailed [...] Read more.
The conceptual and practical issues regarding the reduction of the Haldane-Radić enzymic mechanism, specific for cholinesterase kinetics, to the consecrated or logistically modified Michaelis-Menten kinetics, specific for some mutant enzymes, are here clarified as due to the limited initial substrate concentration, through detailed initial rate and progress curve analysis, even when other classical conditions for such equivalence are not entirely fulfilled. Full article
(This article belongs to the Special Issue Enzyme-Catalyzed Reactions)
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Open AccessArticle
Lancifoliaine, a New Bisbenzylisoquinoline from the Bark of Litsea lancifolia
Molecules 2011, 16(4), 3119-3127; https://doi.org/10.3390/molecules16043119 - 13 Apr 2011
Cited by 12 | Viewed by 5732
Abstract
A new bisbenzylisoquinoline, lancifoliaine (1), together with seven known alkaloids – N-allyllaurolitsine (2), reticuline (3), actinodaphnine, norboldine, pallidine, cassythicine and boldine – were isolated from the stem bark of Litsea lancifolia (Lauraceae). In addition to that [...] Read more.
A new bisbenzylisoquinoline, lancifoliaine (1), together with seven known alkaloids – N-allyllaurolitsine (2), reticuline (3), actinodaphnine, norboldine, pallidine, cassythicine and boldine – were isolated from the stem bark of Litsea lancifolia (Lauraceae). In addition to that of lancifoliaine, complete 13C-NMR data of N-allyl-laurolitsine (2) was also reported. The alkaloidal structures were elucidated by means of high field 1D- and 2D-NMR IR, UV, and LCMS-IT-TOF spectral data. N-Allyllaurolitsine (2) showed a moderate vasorelaxant activity on isolated rat aorta. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle
Chemically Induced Photoswitching of Fluorescent Probes—A General Concept for Super-Resolution Microscopy
Molecules 2011, 16(4), 3106-3118; https://doi.org/10.3390/molecules16043106 - 13 Apr 2011
Cited by 79 | Viewed by 11775
Abstract
We review fluorescent probes that can be photoswitched or photoactivated and are suited for single-molecule localization based super-resolution microscopy. We exploit the underlying photochemical mechanisms that allow photoswitching of many synthetic organic fluorophores in the presence of reducing agents, and study the impact [...] Read more.
We review fluorescent probes that can be photoswitched or photoactivated and are suited for single-molecule localization based super-resolution microscopy. We exploit the underlying photochemical mechanisms that allow photoswitching of many synthetic organic fluorophores in the presence of reducing agents, and study the impact of these on the photoswitching properties of various photoactivatable or photoconvertible fluorescent proteins. We have identified mEos2 as a fluorescent protein that exhibits reversible photoswitching under various imaging buffer conditions and present strategies to characterize reversible photoswitching. Finally, we discuss opportunities to combine fluorescent proteins with organic fluorophores for dual-color photoswitching microscopy. Full article
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Open AccessReview
Lambda-Display: A Powerful Tool for Antigen Discovery
Molecules 2011, 16(4), 3089-3105; https://doi.org/10.3390/molecules16043089 - 13 Apr 2011
Cited by 28 | Viewed by 7605
Abstract
Since its introduction in 1985, phage display technology has been successfully used in projects aimed at deciphering biological processes and isolating molecules of practical value in several applications. Bacteriophage lambda, representing a classical molecular cloning and expression system has also been exploited for [...] Read more.
Since its introduction in 1985, phage display technology has been successfully used in projects aimed at deciphering biological processes and isolating molecules of practical value in several applications. Bacteriophage lambda, representing a classical molecular cloning and expression system has also been exploited for generating large combinatorial libraries of small peptides and protein domains exposed on its capsid. More recently, lambda display has been consistently and successfully employed for domain mapping, antigen discovery and protein interaction studies or, more generally, in functional genomics. We show here the results obtained by the use of large libraries of cDNA and genomic DNA for the molecular dissection of the human B-cell response against complex pathogens, including protozoan parasites, bacteria and viruses. Moreover, by reviewing the experimental work performed in recent investigations we illustrate the potential of lambda display in the diagnostics field and for identifying antigens useful as targets for vaccine development. Full article
(This article belongs to the Special Issue Phage Display of Combinatorial Libraries)
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Open AccessArticle
Components and Insecticidal Activity against the Maize Weevils of Zanthoxylum schinifolium Fruits and Leaves
Molecules 2011, 16(4), 3077-3088; https://doi.org/10.3390/molecules16043077 - 13 Apr 2011
Cited by 63 | Viewed by 8622
Abstract
In our screening program for new agrochemicals from Chinese medicinal herbs and wild plants, Zanthoxylum schinifolium essential oils were found to possess strong insecticidal activity against the maize weevil Sitophilus zeamais. The essential oils of Z. schinifolium fruits and leaves were extracted [...] Read more.
In our screening program for new agrochemicals from Chinese medicinal herbs and wild plants, Zanthoxylum schinifolium essential oils were found to possess strong insecticidal activity against the maize weevil Sitophilus zeamais. The essential oils of Z. schinifolium fruits and leaves were extracted via hydrodistillation and investigated by GC and GC-MS. Estragole (69.52%) was the major compound of the essential oil of fresh fruits, followed by linalool (8.63%) and limonene (4.34%) and 94.33% of the total components were monoterpenoids. The main components of the essential oil of fresh leaves were linalool (12.94%), ar-tumerone (8.95%), limonene (6.45%) and elixene (5.43%) and only 50.62% were monoterpenoids. However, the essential oil from purchased fruits contained linalool (33.42%), limonene (13.66%) and sabinene (5.72%), followed by estragole (4.67%), nerol (4.56%) and 4-terpineol (4.27%). Estragole, linalool and sabinene were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. The essential oil from the fresh fruits (LD50 = 15.93 μg/adult) possessed two times more toxicity to the insects compared with that of fresh leaves (LD50 = 35.31 μg/adult). Estragole, linalool and sabinene exhibited contact activity against S. zeamais with LD50 values of 17.63, 13.90 and 23.98 μg/adult, respectively. The essential oils of Z. schinifolium possessed strong fumigant toxicity against S. zeamais adults with LC50 values of 13.19 mg/L (fresh fruits), 24.04 mg/L (fresh leaves) and 17.63 mg/L (purchased fruits). Estragole, linalool and sabinene also exhibited strong fumigant toxicity against the maize weevils with LC50 values of 14.10, 10.46 and 9.12 mg/L, respectively. Full article
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Open AccessArticle
New Solid Phase Synthesis of Distamycin Analogues
Molecules 2011, 16(4), 3066-3076; https://doi.org/10.3390/molecules16043066 - 11 Apr 2011
Cited by 11 | Viewed by 3800 | Correction
Abstract
A novel and straightforward solid phase synthesis of distamycin analogues containing benzene units has been developed. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle
2D-DIGE Proteomic Analysis of Changes in Estrogen/Progesterone-Induced Rat Breast Hyperplasia upon Treatment with the Mongolian Remedy RuXian-I
Molecules 2011, 16(4), 3048-3065; https://doi.org/10.3390/molecules16043048 - 08 Apr 2011
Cited by 9 | Viewed by 6926
Abstract
RuXian-I has traditionally been used as a remedy for breast hyperplasia in the Inner Mongolia Autonomous Region of China. As a first step toward the investigation of biomarkers associated with RuXian-I treatment, a proteome-wide analysis of rat breast tissue was conducted. First, rat [...] Read more.
RuXian-I has traditionally been used as a remedy for breast hyperplasia in the Inner Mongolia Autonomous Region of China. As a first step toward the investigation of biomarkers associated with RuXian-I treatment, a proteome-wide analysis of rat breast tissue was conducted. First, rat breast hyperplasia was induced by injection of estradiol and progesterone. After treatment with RuXian-I, there is a marked decrease in the hyperplasia, as can be shown by decreases in the nipple diameter and the pathological changes in breast. Subsequently, we used an approach that integrates size-based 2D-DIGE, MALDI-TOF/TOF-MS, and bioinformatics to analyze data from the control group, the model group and the RuXian-I treatment group. Using this approach, seventeen affected proteins were identified. Among these, 15 (including annexin A1, annexin A2, superoxide dismutase [Mn], peroxiredoxin-1, translationally-controlled tumor protein and a B-crystallin) were significantly up-regulated in the model group and down-regulated upon treatment with RuXian-I, and two (Tpil protein and myosin-4) have the opposite change trend. The expression of annexin A1 was confirmed using immunohistochemistry. The expression of superoxide dismutase (SOD) activity was confirmed biochemically. These results indicated that RuXian-I treats rat breast hyperplasia through regulation of cell cycle, immune system, metabolic, signal transduction, etc. The differential expressions of these proteins (annexin A1, superoxide dismutase [Mn], alpha B-crystallins and translationally controlled tumor protein, among others) were associated with occurrence and metastasis of breast cancer. These findings might provide not only far-reaching valuable insights into the mechanism of RuXian-I action, but also leads for prognosis and diagnosis of breast hyperplasia and breast cancer. Full article
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Open AccessArticle
An Antimicrobial Compound Isolated from Cinnamomum Iners Leaves with Activity against Methicillin-Resistant Staphylococcus Aureus
Molecules 2011, 16(4), 3037-3047; https://doi.org/10.3390/molecules16043037 - 08 Apr 2011
Cited by 21 | Viewed by 5735
Abstract
This study was designed to investigate the antimicrobial activity of Cinnamomum iners standardized leave methanolic extract (CSLE), its fractions and isolated compounds. CSLE and fractions were subjected to disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests using different Gram [...] Read more.
This study was designed to investigate the antimicrobial activity of Cinnamomum iners standardized leave methanolic extract (CSLE), its fractions and isolated compounds. CSLE and fractions were subjected to disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests using different Gram positive and Gram negative bacteria and yeast. Within the series of fractions tested, the ethyl acetate fraction was the most active, particularly against methicillin resistant Staphylococcus aureus (MRSA) and Escherichia coli, with MIC values of 100 and 200 µg/mL, respectively. The active compound in this fraction was isolated and identified as xanthorrhizol [5-(1, 5-dimethyl-4-hexenyl)-2-methylphenol] by various spectroscopic techniques. The overall results of this study provide evidence that Cinnamomum iners leaves extract as well as the isolated compound xanthorrhizol exhibit antimicrobial activity for both Gram negative and Gram positive pathogens, especially against MRSA strains. Full article
(This article belongs to the Section Natural Products Chemistry)
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