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Molecules, Volume 18, Issue 8 (August 2013), Pages 8712-10094

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Open AccessArticle Evaluation of Silica-H2SO4 as an Efficient Heterogeneous Catalyst for the Synthesis of Chalcones
Molecules 2013, 18(8), 10081-10094; https://doi.org/10.3390/molecules180810081
Received: 19 July 2013 / Revised: 5 August 2013 / Accepted: 7 August 2013 / Published: 20 August 2013
Cited by 12 | Viewed by 3338 | PDF Full-text (341 KB) | HTML Full-text | XML Full-text
Abstract
We report an efficient silica-H2SO4 mediated synthesis of a variety of chalcones that afforded the targeted compounds in very good yield compared to base catalyzed solvent free conditions as well as acid or base catalyzed refluxing conditions. Full article
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Open AccessArticle Modeling the Interaction of Dodecylphosphocholine Micelles with the Anticoccidial Peptide PW2 Guided by NMR Data
Molecules 2013, 18(8), 10056-10080; https://doi.org/10.3390/molecules180810056
Received: 19 July 2013 / Revised: 5 August 2013 / Accepted: 7 August 2013 / Published: 20 August 2013
Cited by 4 | Viewed by 2921 | PDF Full-text (1475 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Antimicrobial peptides are highly dynamic entities that acquire structure upon binding to a membrane interface. To better understand the structure and the mechanism for the molecular recognition of dodecylphosphocholine (DPC) micelles by the anticoccidial peptide PW2, we performed molecular dynamics (MD) simulations guided
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Antimicrobial peptides are highly dynamic entities that acquire structure upon binding to a membrane interface. To better understand the structure and the mechanism for the molecular recognition of dodecylphosphocholine (DPC) micelles by the anticoccidial peptide PW2, we performed molecular dynamics (MD) simulations guided by NMR experimental data, focusing on strategies to explore the transient nature of micelles, which rearrange on a millisecond to second timescale. We simulated the association of PW2 with a pre-built DPC micelle and with free-DPC molecules that spontaneously forms micelles in the presence of the peptide along the simulation. The simulation with spontaneous micelle formation provided the adequate environment which replicated the experimental data. The unrestrained MD simulations reproduced the NMR structure for the entire 100 ns MD simulation time. Hidden discrete conformational states could be described. Coulomb interactions are important for initial approximation and hydrogen bonds for anchoring the aromatic region at the interface, being essential for the stabilization of the interaction. Arg9 is strongly attached with phosphate. We observed a helix elongation process stabilized by the intermolecular peptide-micelle association. Full association that mimics the experimental data only happens after complete micelle re-association. Fast micelle dynamics without dissociation of surfactants leads to only superficial binding. Full article
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Open AccessCommunication Total Synthesis, Cytotoxic Effects of Damnacanthal, Nordamnacanthal and Related Anthraquinone Analogues
Molecules 2013, 18(8), 10042-10055; https://doi.org/10.3390/molecules180810042
Received: 22 May 2013 / Revised: 29 June 2013 / Accepted: 16 July 2013 / Published: 20 August 2013
Cited by 12 | Viewed by 4105 | PDF Full-text (317 KB) | HTML Full-text | XML Full-text
Abstract
Naturally occurring anthraquinones, damnacanthal (1) and nordamnacanthal (2) were synthesized with modified reaction steps and investigated for their cytotoxicity against the MCF-7 and K-562 cancer cell lines, respectively. Intermediate analogues 2-bromomethyl-1,3-dimethoxyanthraquinone (5, IC50 = 5.70 ±
[...] Read more.
Naturally occurring anthraquinones, damnacanthal (1) and nordamnacanthal (2) were synthesized with modified reaction steps and investigated for their cytotoxicity against the MCF-7 and K-562 cancer cell lines, respectively. Intermediate analogues 2-bromomethyl-1,3-dimethoxyanthraquinone (5, IC50 = 5.70 ± 0.21 and 8.50 ± 1.18 mg/mL), 2-hydroxymethyl-1,3-dimethoxyanthraquinone (6, IC50 = 12.10 ± 0.14 and 14.00 ± 2.13), 2-formyl-1,3-dimethoxyantharquinone (7, IC50 = 13.10 ± 1.02 and 14.80 ± 0.74), 1,3-dimethoxy-2-methylanthraquinone (4, IC50 = 9.40 ± 3.51 and 28.40 ± 2.33), and 1,3-dihydroxy-2-methylanthraquinone (3, IC50 = 25.60 ± 0.42 and 28.40 ± 0.79) also exhibited moderate cytotoxicity against MCF-7 and K-562 cancer cell lines, respectively. Other structurally related compounds like 1,3-dihydroxyanthraquinone (13a, IC50 = 19.70 ± 0.35 and 14.50 ± 1.28), 1,3-dimethoxyanthraquinone (13b, IC50 = 6.50 ± 0.66 and 5.90 ± 0.95) were also showed good cytotoxicity. The target compound damnacanthal (1) was found to be the most cytotoxic against the MCF-7 and K-562 cancer cell lines, with IC50 values of 3.80 ± 0.57 and 5.50 ± 1.26, respectively. The structures of all compounds were elucidated with the help of detailed spectroscopic techniques. Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessArticle Volatile Aroma Compounds in Various Brewed Green Teas
Molecules 2013, 18(8), 10024-10041; https://doi.org/10.3390/molecules180810024
Received: 18 July 2013 / Revised: 7 August 2013 / Accepted: 14 August 2013 / Published: 20 August 2013
Cited by 21 | Viewed by 4024 | PDF Full-text (289 KB) | HTML Full-text | XML Full-text
Abstract
This study identifies and semi-quantifies aroma volatiles in brewed green tea samples. The objectives of this study were to identify using a gas chromatograph-mass spectrometer (GC-MS) paired with a headspace solid-phase micro-extraction (HS-SPME) the common volatile compounds that may be responsible for aroma/flavor
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This study identifies and semi-quantifies aroma volatiles in brewed green tea samples. The objectives of this study were to identify using a gas chromatograph-mass spectrometer (GC-MS) paired with a headspace solid-phase micro-extraction (HS-SPME) the common volatile compounds that may be responsible for aroma/flavor of the brewed liquor of a range of green tea samples from various countries as consumed and to determine if green teas from the same region have similarities in volatile composition when green tea samples are prepared for consumption. Twenty-four green tea samples from eight different countries were brewed as recommended for consumer brewing. The aroma volatiles were extracted by HS-SPME, separated on a gas chromatograph and identified using a mass spectrometer. Thirty-eight compounds were identified and the concentrations were semi-quantified. The concentrations were lower than those reported by other researchers, probably because this research examined headspace volatiles from brewed tea rather than solvent extraction of leaves. No relationship to country of origin was found, which indicates that other factors have a greater influence than country of origin on aroma. Full article
(This article belongs to the Special Issue Flavors and Fragrances)
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Open AccessArticle Antianxiety-Like Effects of Chimpi (Dried Citrus Peels) in the Elevated Open-Platform Test
Molecules 2013, 18(8), 10014-10023; https://doi.org/10.3390/molecules180810014
Received: 16 July 2013 / Revised: 9 August 2013 / Accepted: 16 August 2013 / Published: 20 August 2013
Cited by 7 | Viewed by 2943 | PDF Full-text (258 KB) | HTML Full-text | XML Full-text
Abstract
Dried citrus peels (Chimpi) is one of the most common natural medicines with qi (energy flow) rectifying and shi (dampness) drying actions, which originates from Citrus unshiu, and/or C. reticulata according to the definition of the pharmacopoeiae of Japan and China.
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Dried citrus peels (Chimpi) is one of the most common natural medicines with qi (energy flow) rectifying and shi (dampness) drying actions, which originates from Citrus unshiu, and/or C. reticulata according to the definition of the pharmacopoeiae of Japan and China. In this study, the pharmacological effects of their extracts and major chemical constituents hesperidin and its aglycone hesperetin on anxiety were examined with an anxiety model of elevated open-platform test using ICR male mice (6-week-old) and total duration of freezing was decreased in fluoxetine-treated mice, which is a simple and highly sensitive to the effects of serotonergic anxiolytics. Moreover, yokukansankachimpihange (YKH), a combination of yokukansan with Chimpi and Hange (Pinellia) was also examined because Chimpi is considered to play a crucial part in this formula against anxious symptoms in dementia patients. The results showed that Chimpi and YKH possess a significant anxiolytic-like effect similar to that of fluoxetine, suggesting that they might be similar to fluoxetine in their pharmacological actions through the serotonergic neurotransmission pathway. Moreover, it also suggested that the major chemical constituent, hesperidin could be an active principle attributed to the antianxiety-like effects with a direct and indirect role via its aglycone hesperetin. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Combination of Small Molecule Microarray and Confocal Microscopy Techniques for Live Cell Staining Fluorescent Dye Discovery
Molecules 2013, 18(8), 9999-10013; https://doi.org/10.3390/molecules18089999
Received: 26 June 2013 / Revised: 13 August 2013 / Accepted: 14 August 2013 / Published: 20 August 2013
Cited by 4 | Viewed by 3755 | PDF Full-text (4706 KB) | HTML Full-text | XML Full-text
Abstract
Discovering new fluorochromes is significantly advanced by high-throughput screening (HTS) methods. In the present study a combination of small molecule microarray (SMM) prescreening and confocal laser scanning microscopy (CLSM) was developed in order to discover novel cell staining fluorescent dyes. Compounds with high
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Discovering new fluorochromes is significantly advanced by high-throughput screening (HTS) methods. In the present study a combination of small molecule microarray (SMM) prescreening and confocal laser scanning microscopy (CLSM) was developed in order to discover novel cell staining fluorescent dyes. Compounds with high native fluorescence were selected from a 14,585-member library and further tested on living cells under the microscope. Eleven compartment-specific, cell-permeable (or plasma membrane-targeted) fluorochromes were identified. Their cytotoxicity was tested and found that between 1–10 micromolar range, they were non-toxic even during long-term incubations. Full article
(This article belongs to the Special Issue Reagents and Methods for Protein Target Identification)
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Open AccessArticle Enantio- and Periselective Nitroalkene Diels-Alder Reactions Catalyzed by Helical-Chiral Hydrogen Bond Donor Catalysts
Molecules 2013, 18(8), 9982-9998; https://doi.org/10.3390/molecules18089982
Received: 15 July 2013 / Revised: 13 August 2013 / Accepted: 14 August 2013 / Published: 19 August 2013
Cited by 1 | Viewed by 2719 | PDF Full-text (623 KB) | HTML Full-text | XML Full-text
Abstract
Helical-chiral double hydrogen bond donor catalysts promote the nitroalkene Diels-Alder reaction in an enantio- and periselective manner. This represents the first asymmetric catalytic nitroalkene Diels-Alder reaction via LUMO-lowering catalysis. To gain an insight into this new process, the substrate scope of our catalyst
[...] Read more.
Helical-chiral double hydrogen bond donor catalysts promote the nitroalkene Diels-Alder reaction in an enantio- and periselective manner. This represents the first asymmetric catalytic nitroalkene Diels-Alder reaction via LUMO-lowering catalysis. To gain an insight into this new process, the substrate scope of our catalyst was investigated by exploiting readily available 5-substituted pentamethylcyclopentadienes. The catalyst was found to tolerate dienes with different steric demands as well as dienes substituted with heteroatoms. The synthetic utility of 5-substituted pentamethylcyclopentadienes is rather limited, and thus we have developed a three-step route to 1,4,5,5-tetrasubstituted cyclopentadienes from commercially available ketones. Full article
(This article belongs to the Special Issue Asymmetric Catalysis)
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Open AccessArticle Anti-Lung Cancer Activity through Enhancement of Immunomodulation and Induction of Cell Apoptosis of Total Triterpenes Extracted from Ganoderma luncidum (Leyss. ex Fr.) Karst.
Molecules 2013, 18(8), 9966-9981; https://doi.org/10.3390/molecules18089966
Received: 14 June 2013 / Revised: 2 August 2013 / Accepted: 13 August 2013 / Published: 19 August 2013
Cited by 11 | Viewed by 2962 | PDF Full-text (592 KB) | HTML Full-text | XML Full-text
Abstract
Ganoderma luncidum (Leyss. ex Fr.) Karst. (GLK) has been used traditionally for the prevention and treatment of cancers or tumors for a long time in Traditional Chinese Medicine. The triterpenes as main effective components of GLK have been found to be beneficial for
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Ganoderma luncidum (Leyss. ex Fr.) Karst. (GLK) has been used traditionally for the prevention and treatment of cancers or tumors for a long time in Traditional Chinese Medicine. The triterpenes as main effective components of GLK have been found to be beneficial for the efficacy. The purpose of this study was to examine the anti-lung cancer activity of triterpenes of GLK in vitro and in vivo and to explore their anti-lung cancer effects and potential mechanisms. A549 cells and Lewis tumor-bearing mice were used to evaluate the inhibition effects of triterpenes on cell proliferation and tumor growth. The IC50 of triterpenes of GLK on A549 cells was 24.63 μg/mL. Triterpenes of GLK could significantly inhibit tumor growth in mice (30, 60 and 120 mg/kg). The immune organs indexes including spleen and thymus were increased remarkedly by the treatment with triterpenes. Moreover, they were able to stimulate the immune response by increasing the expressions of IL-6 and TNF-α. Flow cytometric analysis revealed that cell arrest caused by triterpenes treatment (7.5, 15 and 30 μg/mL) was in the G2/M phase in A549 cells. Triterpenes induced apoptosis by decreasing the expression of the antiapoptotic protein Bcl-2 and pro-caspase 9 and increasing the levels of cleaved-caspase 9. Our findings suggested that the triterpenes of GLK have anti-lung cancer activity in vitro and in vivo via enhancement of immunomodulation and induction of cell apoptosis. The study provides insights into the mechanism of GLK in the prevention and treatment of lung cancer. Full article
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Open AccessArticle Neuroprotective, Anti-Amyloidogenic and Neurotrophic Effects of Apigenin in an Alzheimer’s Disease Mouse Model
Molecules 2013, 18(8), 9949-9965; https://doi.org/10.3390/molecules18089949
Received: 21 June 2013 / Revised: 31 July 2013 / Accepted: 6 August 2013 / Published: 19 August 2013
Cited by 53 | Viewed by 4327 | PDF Full-text (607 KB) | HTML Full-text | XML Full-text
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by extracellular senile plaques and intracellular neurofibrillary tangles in the brain. Amyloid-β peptides (Aβ) are considered to play a critical role in the onset and progression of AD. Apigenin (4',5,7-trihydroxyflavone) is a pharmacologically active agent.
[...] Read more.
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by extracellular senile plaques and intracellular neurofibrillary tangles in the brain. Amyloid-β peptides (Aβ) are considered to play a critical role in the onset and progression of AD. Apigenin (4',5,7-trihydroxyflavone) is a pharmacologically active agent. Even though some evidence suggests that it has potential neuroprotective effects, no preexisting study has reported any therapeutic effects of apigenin in AD models. In the present study, we examined the effects of apigenin on cognitive function in APP/PS1 double transgenic AD mice and explored its mechanism(s) of action. Three-month oral treatment with apigenin rescued learning deficits and relieved memory retention in APP/PS1 mice. Apigenin also showed effects affecting APP processing and preventing Aβ burden due to the down-regulation of BACE1 and β-CTF levels, the relief of Aβ deposition, and the decrease of insoluble Aβ levels. Moreover, apigenin exhibited superoxide anion scavenging effects and improved antioxidative enzyme activity of superoxide dismutase and glutathione peroxidase. In addition, apigenin restored neurotrophic ERK/CREB/BDNF pathway in the cerebral cortex. In conclusion, apigenin may ameliorate AD-associated learning and memory impairment through relieving Aβ burden, suppressing amyloidogenic process, inhibiting oxidative stress, and restoring ERK/CREB/BDNF pathway. Therefore, apigenin appears to represent an alternative medication for the prevention and/or therapy of AD. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Characterization and Bioactivity of Polysaccharides Obtained from Pine Cones of Pinus koraiensis by Graded Ethanol Precipitation
Molecules 2013, 18(8), 9933-9948; https://doi.org/10.3390/molecules18089933
Received: 8 June 2013 / Revised: 14 August 2013 / Accepted: 15 August 2013 / Published: 19 August 2013
Cited by 19 | Viewed by 2991 | PDF Full-text (284 KB) | HTML Full-text | XML Full-text
Abstract
Pinus koraiensis polysaccharides (PKP) were extracted by hot water from P. koraiensis pine cones. Five polysaccharide fractions named PKP-A, PKP-B, PKP-C, PKP-D and PKP-E were successfully separated at final ethanol concentrations of 30%, 50%, 60%, 70% and 80%, respectively. HPLC, FT-IR, GC-MS and
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Pinus koraiensis polysaccharides (PKP) were extracted by hot water from P. koraiensis pine cones. Five polysaccharide fractions named PKP-A, PKP-B, PKP-C, PKP-D and PKP-E were successfully separated at final ethanol concentrations of 30%, 50%, 60%, 70% and 80%, respectively. HPLC, FT-IR, GC-MS and automatic amino-acid analysis were applied to investigate their chemical characteristics. Monosaccharide component analysis indicated that the five fractions were all composed of d-ribose, l-rhamnose, l-arabinose, d-xylose, d-mannose, d-glucose and d-galactose, but their molar ratios were quite different. HPLC results revealed that the polysaccharides precipitated by higher concentrations of ethanol solution had lower molecular masses. Moreover, the antioxidant activities of the five fractions were studied on the basis of hydroxyl radical and ABTS radical scavenging tests. The five graded polysaccharide fractions exhibited good inhibitory power, and MTT tests in vitro showed the IC50 of PKP-A and PKP-E were 1,072.5 and 2,070.0 μg·mL−1, respectively. These results demonstrated that the PKP could be a potential source of natural antioxidants or dietary supplements. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Chemistry and Antiviral Activity of Arrabidaea pulchra (Bignoniaceae)
Molecules 2013, 18(8), 9919-9932; https://doi.org/10.3390/molecules18089919
Received: 26 April 2013 / Revised: 22 July 2013 / Accepted: 24 July 2013 / Published: 16 August 2013
Cited by 7 | Viewed by 3024 | PDF Full-text (907 KB) | HTML Full-text | XML Full-text
Abstract
The aim of the present work was to carry out a bioguided isolation of antiviral chemical constituents from an ethanol extract of leaves from Arrabidaea pulchra (Cham.) Sandwith (EEAPL) that had shown in vitro activity in a previous screening using DNA and RNA
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The aim of the present work was to carry out a bioguided isolation of antiviral chemical constituents from an ethanol extract of leaves from Arrabidaea pulchra (Cham.) Sandwith (EEAPL) that had shown in vitro activity in a previous screening using DNA and RNA viruses. The activity of EEPAL was evaluated against the DNA viruses Human herpesvirus 1 (HSV-1) and Vaccinia virus Western Reserve (VACV-WR) as well as against the RNA viruses Murine encephalomyocarditis virus (EMCV), and Dengue virus 2 (DENV-2) by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Cytotoxicity was determined in LLCMK2 and Vero cells and the Selectivity Indexes (SI) were calculated. The most potent effect was observed against DENV-2 (EC50 46.8 ± 1.6 µg mL−1; SI 2.7). For HSV-1 and VACV-WR EC50 values > 200 µg mL−1 were determined, while no inhibition of the cytopathic effect was observed with EMCV. Bioguided fractionation of EEAPL by partition between immiscible solvents followed by chromatography over a Sephadex LH20 column afforded two arylpropanoid glycosides, verbascoside (AP 1) and caffeoylcalleryanin (AP 2), along with a terpenoid, ursolic acid (AP 3). AP 1 and AP 3 exhibited similar anti-DENV-2 profiles, with SI values of 3.8 and 3.1, respectively, while AP 2 was the most effective anti-DENV-2 constituent, with a SI of 20.0. Our results show that A. pulchra leaves ethanol extract (EEAPL) affords compounds with antiviral activity, mainly against DENV-2. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Kinetics of Nitric Oxide and Oxygen Gases on Porous Y-Stabilized ZrO2-Based Sensors
Molecules 2013, 18(8), 9901-9918; https://doi.org/10.3390/molecules18089901
Received: 15 July 2013 / Revised: 8 August 2013 / Accepted: 13 August 2013 / Published: 16 August 2013
Cited by 4 | Viewed by 2536 | PDF Full-text (1926 KB) | HTML Full-text | XML Full-text
Abstract
Using impedance spectroscopy the electrical response of sensors with various porous Y-stabilized ZrO2 (YSZ) microstructures was measured for gas concentrations containing 0–100 ppm NO with 10.5%O2 at temperatures ranging from 600–700 °C. The impedance response increased substantially as the sensor porosity
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Using impedance spectroscopy the electrical response of sensors with various porous Y-stabilized ZrO2 (YSZ) microstructures was measured for gas concentrations containing 0–100 ppm NO with 10.5%O2 at temperatures ranging from 600–700 °C. The impedance response increased substantially as the sensor porosity increased from 46%–50%. Activation energies calculated based on data from the impedance measurements increased in magnitude (97.4–104.9 kJ/mol for 100 ppm NO) with respect to increasing YSZ porosity. Analysis of the oxygen partial pressure dependence of the sensors suggested that dissociative adsorption was the dominant rate limiting. The PWC/DNP theory level was used to investigate the gas-phase energy barrier of the 2NO+O2→2NO2 reaction on a 56-atom YSZ/Au model cluster using Density Functional Theory and Linear Synchronous Transit/Quadratic Synchronous Transit calculations. The reaction path shows oxygen surface reactions that begin with NO association with adsorbed O2 on a Zr surface site, followed by O2 dissociative adsorption, atomic oxygen diffusion, and further NO2 formation. The free energy barrier was calculated to be 181.7 kJ/mol at PWC/DNP. A qualitative comparison with the extrapolated data at 62% ± 2% porosity representing the YSZ model cluster indicates that the calculated barriers are in reasonable agreement with experiments, especially when the RPBE functional is used. Full article
(This article belongs to the Special Issue Gas Phase Reactions)
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Open AccessReview Breathing Some New Life into an Old Topic: Chalcogen-Nitrogen π-Heterocycles as Electron Acceptors
Molecules 2013, 18(8), 9850-9900; https://doi.org/10.3390/molecules18089850
Received: 3 July 2013 / Revised: 13 August 2013 / Accepted: 14 August 2013 / Published: 16 August 2013
Cited by 52 | Viewed by 3331 | PDF Full-text (2445 KB) | HTML Full-text | XML Full-text
Abstract
Recent progress in the design, synthesis and characterization of chalcogen-nitrogen π-heterocycles, mostly 1,2,5-chalcogenadiazoles (chalcogen: S, Se and Te) and their fused derivatives, possessing positive electron affinity is discussed together with their use in preparation of charge-transfer complexes and radical-anion salts—candidate building blocks of
[...] Read more.
Recent progress in the design, synthesis and characterization of chalcogen-nitrogen π-heterocycles, mostly 1,2,5-chalcogenadiazoles (chalcogen: S, Se and Te) and their fused derivatives, possessing positive electron affinity is discussed together with their use in preparation of charge-transfer complexes and radical-anion salts—candidate building blocks of molecule-based electrical and magnetic functional materials. Full article
(This article belongs to the Special Issue Chalcogen-Nitrogen Chemistry)
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Open AccessArticle ADIBO-Based “Click” Chemistry for Diagnostic Peptide Micro-Array Fabrication: Physicochemical and Assay Characteristics
Molecules 2013, 18(8), 9833-9849; https://doi.org/10.3390/molecules18089833
Received: 1 July 2013 / Revised: 25 July 2013 / Accepted: 6 August 2013 / Published: 16 August 2013
Cited by 12 | Viewed by 3863 | PDF Full-text (1150 KB) | HTML Full-text | XML Full-text
Abstract
Several azide-derivatized and fluorescently-labeled peptides were immobilized on azadibenzocyclooctyne (ADIBO)-activated slide surfaces via a strain-promoted alkyne-azide cycloaddition (SPAAC) reaction revealing excellent immobilization kinetics, good spot homogeneities and reproducible fluorescence signal intensities. A myc-peptide micro-array immunoassay showed an antibody limit-of-detection (LOD) superior to
[...] Read more.
Several azide-derivatized and fluorescently-labeled peptides were immobilized on azadibenzocyclooctyne (ADIBO)-activated slide surfaces via a strain-promoted alkyne-azide cycloaddition (SPAAC) reaction revealing excellent immobilization kinetics, good spot homogeneities and reproducible fluorescence signal intensities. A myc-peptide micro-array immunoassay showed an antibody limit-of-detection (LOD) superior to a microtiter plate-based ELISA. Bovine serum albumin (BSA) and dextran covalently attached via “click” chemistry more efficiently reduced non-specific binding (NSB) of fluorescently-labeled IgG to the microarray surface in comparison to immobilized hexanoic acid and various types of polyethylene glycol (PEG) derivatives. Confirmation of these findings via further studies with other proteins and serum components could open up new possibilities for human sample and microarray platform-based molecular diagnostic tests. Full article
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Open AccessArticle Eco-Friendly Synthesis and Antiproliferative Evaluation of Some Oxygen Substituted Diaryl Ketones
Molecules 2013, 18(8), 9818-9832; https://doi.org/10.3390/molecules18089818
Received: 26 June 2013 / Revised: 5 August 2013 / Accepted: 12 August 2013 / Published: 16 August 2013
Cited by 10 | Viewed by 3070 | PDF Full-text (320 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A broad variety of oxygen-substituted diaryl ketones has been synthesized by solar energy-induced Friedel Crafts acylations of 1,4-benzo- and 1,4-naphthoquinones with benzaldehydes. The in vitro antiproliferative properties of the photoproducts were assessed on prostate (DU-145), bladder (T24) and breast (MCF7) human-derived tumor cell
[...] Read more.
A broad variety of oxygen-substituted diaryl ketones has been synthesized by solar energy-induced Friedel Crafts acylations of 1,4-benzo- and 1,4-naphthoquinones with benzaldehydes. The in vitro antiproliferative properties of the photoproducts were assessed on prostate (DU-145), bladder (T24) and breast (MCF7) human-derived tumor cell lines and compared to non-tumor mouse fibroblasts (Balb/3T3). Among the tested compounds, it was found that those containing a 3,4,5-trimethoxyphenyl A-ring, such as 12 and 22 are more active on DU-145, with EC50 values of 1.2 and 5.9 μM, respectively. By comparing their effects on the three cancer cell lines, the analogue 22 has the best mean selective index (2.4). Full article
(This article belongs to the Section Organic Chemistry)
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Open AccessReview Click Chemistry in Peptide-Based Drug Design
Molecules 2013, 18(8), 9797-9817; https://doi.org/10.3390/molecules18089797
Received: 15 July 2013 / Revised: 9 August 2013 / Accepted: 12 August 2013 / Published: 16 August 2013
Cited by 64 | Viewed by 5414 | PDF Full-text (702 KB) | HTML Full-text | XML Full-text
Abstract
Click chemistry is an efficient and chemoselective synthetic method for coupling molecular fragments under mild reaction conditions. Since the advent in 2001 of methods to improve stereochemical conservation, the click chemistry approach has been broadly used to construct diverse chemotypes in both chemical
[...] Read more.
Click chemistry is an efficient and chemoselective synthetic method for coupling molecular fragments under mild reaction conditions. Since the advent in 2001 of methods to improve stereochemical conservation, the click chemistry approach has been broadly used to construct diverse chemotypes in both chemical and biological fields. In this review, we discuss the application of click chemistry in peptide-based drug design. We highlight how triazoles formed by click reactions have been used for mimicking peptide and disulfide bonds, building secondary structural components of peptides, linking functional groups together, and bioconjugation. The progress made in this field opens the way for synthetic approaches to convert peptides with promising functional leads into structure-minimized and more stable forms. Full article
(This article belongs to the collection Advances in Click Chemistry)
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Open AccessArticle Chemical Composition and Biological Activities of Essential Oils of Eremanthus erythropappus (DC) McLeisch (Asteraceae)
Molecules 2013, 18(8), 9785-9796; https://doi.org/10.3390/molecules18089785
Received: 19 July 2013 / Revised: 6 August 2013 / Accepted: 8 August 2013 / Published: 16 August 2013
Cited by 21 | Viewed by 3098 | PDF Full-text (223 KB) | HTML Full-text | XML Full-text
Abstract
The chemical composition of the essential oils obtained by hydrodistillation of different parts of Eremanthus erythropappus, including leaves, branches and inflorescences, was investigated by Gas Chromatography and Gas Chromatography/Mass Spectrometry. The antimicrobial activity of the oils was assessed by the disc diffusion
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The chemical composition of the essential oils obtained by hydrodistillation of different parts of Eremanthus erythropappus, including leaves, branches and inflorescences, was investigated by Gas Chromatography and Gas Chromatography/Mass Spectrometry. The antimicrobial activity of the oils was assessed by the disc diffusion and microdilution methods, while the antioxidant activity was evaluated by DPPH and reducing power tests. The main compounds found in the essential oils derived from the inflorescences and leaves were β-caryophyllene, germacrene-D, α-copaene and β-pinene. α-Bisabolol was the major component in the branches. The oils were active against Staphylococcus aureus, Streptococcus pyogenes and fungi, but not Escherichia coli and Pseudomonas aeruginosa. The MIC values ranged from 0.01 to 0.50 mg/mL. Using the DPPH test, the IC50 values ranged from 38.77 ± 0.76 to 102.24 ± 1.96 μg/mL, while the reducing power test produced IC50 values between 109.85 ± 1.68 and 169.53 ± 0.64 μg/mL. The results revealed that the E. erythropappus oils are new promising potential sources of antimicrobial and antioxidant compounds with good future practical applications for human health. Full article
(This article belongs to the Section Natural Products Chemistry)
Open AccessArticle Antidiabetic and Antioxidant Properties of Alkaloids from Catharanthus roseus (L.) G. Don
Molecules 2013, 18(8), 9770-9784; https://doi.org/10.3390/molecules18089770
Received: 17 June 2013 / Revised: 2 August 2013 / Accepted: 9 August 2013 / Published: 15 August 2013
Cited by 50 | Viewed by 6347 | PDF Full-text (1758 KB) | HTML Full-text | XML Full-text
Abstract
Catharanthus roseus (L.) G. Don is a herbal plant traditionally used by local populations in India, South Africa, China and Malaysia to treat diabetes. The present study reports the in vitro antioxidant and antidiabetic activities of the major alkaloids isolated from Catharanthus roseus
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Catharanthus roseus (L.) G. Don is a herbal plant traditionally used by local populations in India, South Africa, China and Malaysia to treat diabetes. The present study reports the in vitro antioxidant and antidiabetic activities of the major alkaloids isolated from Catharanthus roseus (L.) G. Don leaves extract. Four alkaloids—vindoline I, vindolidine II, vindolicine III and vindolinine IV—were isolated and identified from the dichloromethane extract (DE) of this plant’s leaves. DE and compounds IIII were not cytotoxic towards pancreatic β-TC6 cells at the highest dosage tested (25.0 µg/mL). All four alkaloids induced relatively high glucose uptake in pancreatic β-TC6 or myoblast C2C12 cells, with III showing the highest activity. In addition, compounds IIIV demonstrated good protein tyrosine phosphatase-1B (PTP-1B) inhibition activity, implying their therapeutic potential against type 2 diabetes. III showed the highest antioxidant potential in ORAC and DPPH assays and it also alleviated H2O2-induced oxidative damage in β-TC6 cells at 12.5 µg/mL and 25.0 µg/mL. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Characterization of Nucleosides and Nucleobases in Natural Cordyceps by HILIC–ESI/TOF/MS and HILIC–ESI/MS
Molecules 2013, 18(8), 9755-9769; https://doi.org/10.3390/molecules18089755
Received: 2 July 2013 / Accepted: 8 August 2013 / Published: 15 August 2013
Cited by 18 | Viewed by 3127 | PDF Full-text (265 KB) | HTML Full-text | XML Full-text
Abstract
A method combining hydrophilic interaction chromatography (HILIC) and electrospray ionization mass spectrometry (ESI-MS) was developed for the characterization and determination of natural Cordyceps. Separation was achieved on a Waters Xbridge Amide column with gradient elution. Identification of 15 target nucleosides and nucleobases
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A method combining hydrophilic interaction chromatography (HILIC) and electrospray ionization mass spectrometry (ESI-MS) was developed for the characterization and determination of natural Cordyceps. Separation was achieved on a Waters Xbridge Amide column with gradient elution. Identification of 15 target nucleosides and nucleobases was based on retention time, UV spectra and mass measurements of the protonated molecules ([M+H]+) and main fragment ions (ESI-TOF/MS). Eight non-target compounds were tentatively identified by ESI-TOF/MS. The 15 target compounds were quantified by HILIC-ESI-MS/MS using time-programmed selective ion monitoring or multiple reaction monitoring in positive-ion mode under optimized mass conditions. This technique showed good linearity, repeatability and recovery. This approach was also successfully implemented in the analysis of nucleosides and nucleobases in 12 batches of natural Cordyceps samples that were collected from different regions in China. The developed HILIC-ESI-MS method exhibited clear advantages in identifying and determining highly polar bioactive components in Cordyceps, as well as their quality control. Full article
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Open AccessArticle NMR Study on the Interaction of Trehalose with Lactose and Its Effect on the Hydrogen Bond Interaction in Lactose
Molecules 2013, 18(8), 9735-9754; https://doi.org/10.3390/molecules18089735
Received: 20 June 2013 / Revised: 31 July 2013 / Accepted: 7 August 2013 / Published: 14 August 2013
Cited by 6 | Viewed by 3501 | PDF Full-text (840 KB) | HTML Full-text | XML Full-text
Abstract
Trehalose, a well-known stress-protector of biomolecules, has been investigated for its effect on the mobility, hydration and hydrogen bond interaction of lactose using diffusion-ordered NMR spectroscopy and NMR of hydroxy protons. In ternary mixtures of trehalose, lactose and water, the two sugars have
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Trehalose, a well-known stress-protector of biomolecules, has been investigated for its effect on the mobility, hydration and hydrogen bond interaction of lactose using diffusion-ordered NMR spectroscopy and NMR of hydroxy protons. In ternary mixtures of trehalose, lactose and water, the two sugars have the same rate of diffusion. The chemical shifts, temperature coefficients, vicinal coupling constants and ROE of the hydroxy protons in trehalose, lactose and sucrose were measured for the disaccharides alone in water/acetone-d6 solutions as well as in mixtures. The data indicated that addition of trehalose did not change significantly the strength of the hydrogen bond interaction between GlcOH3 and GalO5' in lactose. Small upfield shifts were however measured for all hydroxy protons when the sugar concentration was increased. The chemical shift of the GlcOH3 signal in lactose showed less change, attributed to the spatial proximity to GalO5'. Chemical exchange between hydroxy protons of lactose and trehalose was observed in the ROESY NMR spectra. Similar effects were observed with sucrose indicating no specific effect of trehalose at the concentrations investigated (73 to 763 mg/mL) and suggesting that it is the concentration of hydroxy groups more than the type of sugars which is guiding intermolecular interactions. Full article
(This article belongs to the Special Issue NMR of Proteins and Small Biomolecules)
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Open AccessArticle Uncarilic Acid and Secouncarilic Acid, Two New Triterpenoids from Uucaria sessilifructus
Molecules 2013, 18(8), 9727-9734; https://doi.org/10.3390/molecules18089727
Received: 29 May 2013 / Revised: 26 July 2013 / Accepted: 29 July 2013 / Published: 14 August 2013
Cited by 3 | Viewed by 2906 | PDF Full-text (446 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Two new compounds, the 6-oxo oleanane-type triterpenoid uncarilic acid, and its 5,6-secotriterpenoid derivative, secouncarilic acid, were isolated from the hooks and stems of Uucaria sessilifructus together with seven known ursane-type triterpenoids. Uncarilic acid is the second 6-oxo oleanane-type triterpenoid ever reported, while secouncarilic
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Two new compounds, the 6-oxo oleanane-type triterpenoid uncarilic acid, and its 5,6-secotriterpenoid derivative, secouncarilic acid, were isolated from the hooks and stems of Uucaria sessilifructus together with seven known ursane-type triterpenoids. Uncarilic acid is the second 6-oxo oleanane-type triterpenoid ever reported, while secouncarilic acid is the first oleanane-type 5,6-secotriterpenoid. A plausible biosynthetic pathway from uncarilic acid to secouncarilic acid was also postulated. The inhibitory activities of all the nine compounds against LPS-induced nitric oxide production in RAW264.7 macrophages were evaluated. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Highly Efficient Biotransformation of Polydatin to Resveratrol by Snailase Hydrolysis Using Response Surface Methodology Optimization
Molecules 2013, 18(8), 9717-9726; https://doi.org/10.3390/molecules18089717
Received: 5 June 2013 / Revised: 15 July 2013 / Accepted: 16 July 2013 / Published: 13 August 2013
Cited by 6 | Viewed by 3429 | PDF Full-text (790 KB) | HTML Full-text | XML Full-text
Abstract
Resveratrol (RV), a dietary antioxidant polyphenolic compound found in grapes and red wine, exerts a wide variety of pharmacological activities. However, lower content in plants compared with polydatin (PD, the glucoside of RV) limits its application in the food and pharmaceutical industries. In
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Resveratrol (RV), a dietary antioxidant polyphenolic compound found in grapes and red wine, exerts a wide variety of pharmacological activities. However, lower content in plants compared with polydatin (PD, the glucoside of RV) limits its application in the food and pharmaceutical industries. In this paper, we carried out efficient biotransformation of PD to RV with 100% conversion yield by snailase hydrolysis. Moreover, response surface methodology (RSM) was used to optimize the effects of the reaction temperature, enzyme load, and reaction time on the conversion process. Validation of the RSM model was verified by the good agreement between the experimental and the predicted RV yield values. The optimum preparation conditions were as follows: temperature of 62.0 °C, enzyme load of 6.6%, and reaction time of 96 min. The proposed method may be highly applicable for the enzymatic preparation of RV for medicinal purposes. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Enzymatic Synthesis of Extremely Pure Triacylglycerols Enriched in Conjugated Linoleic Acids
Molecules 2013, 18(8), 9704-9716; https://doi.org/10.3390/molecules18089704
Received: 10 May 2013 / Revised: 5 August 2013 / Accepted: 12 August 2013 / Published: 13 August 2013
Cited by 9 | Viewed by 2681 | PDF Full-text (1154 KB) | HTML Full-text | XML Full-text
Abstract
This work was objectively targeted to synthesize extremely pure triacylglycerols (TAG) enriched in conjugated linoleic acids (CLAs) for medical and dietetic purposes. Extremely pure CLA-enriched TAG was successfully synthesized by using the multi-step process: TAG was primarily synthesized by lipase-catalyzed esterification of CLA
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This work was objectively targeted to synthesize extremely pure triacylglycerols (TAG) enriched in conjugated linoleic acids (CLAs) for medical and dietetic purposes. Extremely pure CLA-enriched TAG was successfully synthesized by using the multi-step process: TAG was primarily synthesized by lipase-catalyzed esterification of CLA and glycerol and then the lower glycerides [monoacylglycerol (MAG) and diacylglycerol (DAG)] in the esterification mixtures was hydrolyzed to free fatty acids (FFAs) by a mono- and di-acylglycerol lipase (lipase SMG1), finally, the FFAs were further separated from TAG by low temperature (150 °C) molecular distillation. The operation parameters for the lipase SMG1-catalyzed hydrolysis were optimized using response surface methodology based on the central composite rotatable design (CCRD). The operation parameters included water content, pH and reaction temperature and all of these three parameters showed significant effects on the hydrolysis of lower glycerides. The optimal conditions were obtained with a water content of 66.4% (w/w, with respect to oil mass), pH at 5.7 and 1 h of reaction time at 19.6 °C. Under these conditions, the content of lower glycerides in the reaction mixture decreased from 45.2% to 0.3% and the purity of CLA-enriched TAG reached 99.7%. Further purification of TAG was accomplished by molecular distillation and the final CLA-enriched TAG product yielded 99.8% of TAG. These extremely pure CLA-enriched TAG would be used for in vivo studies in animals and humans in order to get specific information concerning CLA metabolism. Full article
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Open AccessArticle The Synthesis and the Biological Evaluation of New Thiazolidin-4-one Derivatives Containing a Xanthine Moiety
Molecules 2013, 18(8), 9684-9703; https://doi.org/10.3390/molecules18089684
Received: 10 July 2013 / Accepted: 5 August 2013 / Published: 13 August 2013
Cited by 13 | Viewed by 2614 | PDF Full-text (440 KB) | HTML Full-text | XML Full-text
Abstract
Starting from theophylline (1,3-dimethylxanthine) new thiazolidin-4-one derivatives 7a1–7, 7b1–7 have been synthesized as potential antidiabetic drugs. The structure of the new derivatives was confirmed using spectral methods (FT-IR, 1H-NMR, 13C-NMR). The in vitro antioxidant potential of the synthesized
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Starting from theophylline (1,3-dimethylxanthine) new thiazolidin-4-one derivatives 7a1–7, 7b1–7 have been synthesized as potential antidiabetic drugs. The structure of the new derivatives was confirmed using spectral methods (FT-IR, 1H-NMR, 13C-NMR). The in vitro antioxidant potential of the synthesized compounds was evaluated according to the ferric reducing power, the total antioxidant activity and the DPPH and ABTS radical scavenging assays. Reactive oxygen species (ROS) and free radicals are considered to be implicated in a variety of pathological events, such as diabetes mellitus and its micro- and macrovascular complications. The results of chemical modulation of the thiazolidin-4-one intermediaries 6a, 6b through condensation with several aromatic aldehydes is the improvement of the antioxidant effect. All benzylidenethiazolidin-4-one derivatives 7a1–7, 7b1–7 are more active than their parent thiazolidin-4-ones. The most active compounds are the ones obtained by reaction of condensation with 4-hydroxybenzaldehyde (compounds 7a5, 7a6), 4-dimethylaminobenzaldehyde (compounds 7a6, 7b6) and 2-nitrobenzaldehyde (compounds 7a7, 7b7). Full article
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Open AccessReview The Emerging Role of Ferumoxytol-Enhanced MRI in the Management of Cerebrovascular Lesions
Molecules 2013, 18(8), 9670-9683; https://doi.org/10.3390/molecules18089670
Received: 14 June 2013 / Accepted: 8 August 2013 / Published: 13 August 2013
Cited by 18 | Viewed by 2939 | PDF Full-text (410 KB) | HTML Full-text | XML Full-text
Abstract
Inflammation is increasingly being understood to be a key component to the pathophysiology of cerebrovascular lesions. Ferumoxytol, an iron oxide nanoparticle coated by a carbohydrate shell, has been used in MRI studies as an inflammatory marker because it is cleared by macrophages. Ferumoxytol-enhanced
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Inflammation is increasingly being understood to be a key component to the pathophysiology of cerebrovascular lesions. Ferumoxytol, an iron oxide nanoparticle coated by a carbohydrate shell, has been used in MRI studies as an inflammatory marker because it is cleared by macrophages. Ferumoxytol-enhanced MRI has emerged as an important tool for noninvasive assessment of the inflammatory status of cerebrovascular lesions, namely aneurysms and arteriovenous malformations. Moreover, preliminary evidence suggests that ferumoxytol-enhanced MRI could be applied as a non-invasive tool to differentiate “unstable” lesions that require early intervention from “stable” lesions in which observation may be safe. Assessment of the effects of anti-inflammatory pharmacological interventions on cerebrovascular lesions is also a potentially crucial application of the technique. Future improvements in technique and MRI signal quantification will certainly pave the way for widespread and efficient use of ferumoxytol-enhanced MRI in clinical practice. In this paper, we review current data regarding ferumoxytol-enhanced MRI and discuss its current/potential applications and future perspectives. Full article
(This article belongs to the Special Issue Contrast Agents)
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Open AccessArticle Three Novel Xanthones from Garcinia paucinervis and Their Anti-TMV Activity
Molecules 2013, 18(8), 9663-9669; https://doi.org/10.3390/molecules18089663
Received: 6 June 2013 / Revised: 2 August 2013 / Accepted: 5 August 2013 / Published: 13 August 2013
Cited by 19 | Viewed by 2556 | PDF Full-text (205 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Phytochemical investigations of the leaves of Garcinia paucinervis resulted in the isolation of three new xanthones 13 and five known analogues 48. Structural elucidations of 13 were performed by spectral methods such as 1D and 2D
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Phytochemical investigations of the leaves of Garcinia paucinervis resulted in the isolation of three new xanthones 13 and five known analogues 48. Structural elucidations of 13 were performed by spectral methods such as 1D and 2D (HMQC, HMBC, and ROESY) NMR spectroscopy, in addition to high resolution mass spectrometry. Compounds 13 showed anti-TMV activities, with inhibition rates above 20%, especially for 1, which had a lower IC50 value of 21.4 µM. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessReview Ring Expansion of Vinylaziridines through the Strain-Release Pericyclic Reaction: Recent Developments and Applications
Molecules 2013, 18(8), 9650-9662; https://doi.org/10.3390/molecules18089650
Received: 23 July 2013 / Revised: 1 August 2013 / Accepted: 7 August 2013 / Published: 12 August 2013
Cited by 8 | Viewed by 2884 | PDF Full-text (612 KB) | HTML Full-text | XML Full-text
Abstract
Recent syntheses of azetidines, pyrrolidines, piperidines and azepines through cycloaddition or sigmatropic rearrangements of vinylaziridines are described. Applications to natural product synthesis and mechanistic investigations are also summarized. Full article
(This article belongs to the Special Issue Bioorthogonal Chemistry)
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Open AccessArticle Phenylpropanoid, Sapnol A, Lignan and Neolignan Sophorosides, Saposides A and B, Isolated from Canadian Sugar Maple Sap
Molecules 2013, 18(8), 9641-9649; https://doi.org/10.3390/molecules18089641
Received: 19 July 2013 / Revised: 7 August 2013 / Accepted: 8 August 2013 / Published: 12 August 2013
Cited by 5 | Viewed by 2357 | PDF Full-text (309 KB) | HTML Full-text | XML Full-text
Abstract
One new phenolic compound, sapnol A (1), and two new aromatic sophorosides, named saposides A (2) and B (3) were isolated from sugar maple sap. In addition, seven known phenolic compounds 410 were isolated. These
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One new phenolic compound, sapnol A (1), and two new aromatic sophorosides, named saposides A (2) and B (3) were isolated from sugar maple sap. In addition, seven known phenolic compounds 410 were isolated. These structures were determined on the basis of NMR experiments as well as chemical evidence. Furthermore, all the isolated compounds 110 were tested for antioxidative activity by the superoxide dismutase (SOD)-like assay. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Susceptibility of Staphylococcus aureus Clinical Isolates to Propolis Extract Alone or in Combination with Antimicrobial Drugs
Molecules 2013, 18(8), 9623-9640; https://doi.org/10.3390/molecules18089623
Received: 6 June 2013 / Revised: 23 July 2013 / Accepted: 26 July 2013 / Published: 12 August 2013
Cited by 28 | Viewed by 4086 | PDF Full-text (503 KB) | HTML Full-text | XML Full-text
Abstract
The objective of this study was to assess in vitro the antimicrobial activity of ethanolic extract of Polish propolis (EEPP) against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates. The combined effect of EEPP and 10 selected antistaphylococcal drugs on
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The objective of this study was to assess in vitro the antimicrobial activity of ethanolic extract of Polish propolis (EEPP) against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates. The combined effect of EEPP and 10 selected antistaphylococcal drugs on S. aureus clinical cultures was also investigated. EEPP composition was analyzed by a High Performance Liquid Chromatography (HPLC) method. The flavonoid compounds identified in Polish Propolis included flavones, flavonones, flavonolols, flavonols and phenolic acids. EEPP displayed varying effectiveness against twelve S. aureus strains, with minimal inhibitory concentration (MIC) within the range from 0.39 to 0.78 mg/mL, determined by broth microdilution method. The average MIC was 0.54 ± 0.22 mg/mL, while calculated MIC50 and MIC90 were 0.39 mg/mL and 0.78 mg/mL, respectively. The minimum bactericidal concentration (MBC) of the EEPP ranged from 0.78 to 3.13 mg/mL. The in vitro combined effect of EEPP and 10 antibacterial drugs was investigated using disk diffusion method-based assay. Addition of EEPP to cefoxitin (FOX), clindamycin (DA), tetracycline (TE), tobramycin (TOB), linezolid (LIN), trimethoprim+sulfamethoxazole (SXT), penicillin (P), erythromycin (E) regimen, yielded stronger, cumulative antimicrobial effect, against all tested S. aureus strains than EEPP and chemotherapeutics alone. In the case of ciprofloxacin (CIP) and chloramphenicol (C) no synergism with EEPP was observed. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Synthesis of Photoresponsive Dual NIR Two-Photon Absorptive [60]Fullerene Triads and Tetrads
Molecules 2013, 18(8), 9603-9622; https://doi.org/10.3390/molecules18089603
Received: 18 June 2013 / Revised: 30 July 2013 / Accepted: 5 August 2013 / Published: 12 August 2013
Cited by 3 | Viewed by 2957 | PDF Full-text (867 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Broadband nonlinear optical (NLO) organic nanostructures exhibiting both ultrafast photoresponse and a large cross-section of two-photon absorption throughout a wide NIR spectrum may make them suitable for use as nonlinear biophotonic materials. We report here the synthesis and characterization of two C60
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Broadband nonlinear optical (NLO) organic nanostructures exhibiting both ultrafast photoresponse and a large cross-section of two-photon absorption throughout a wide NIR spectrum may make them suitable for use as nonlinear biophotonic materials. We report here the synthesis and characterization of two C60-(antenna)x analogous compounds as branched triad C60(>DPAF-C18)(>CPAF-C2M) and tetrad C60(>DPAF-C18)(>CPAF-C2M)2 nanostructures. These compounds showed approximately equal extinction coefficients of optical absorption over 400–550 nm that corresponds to near-IR two-photon based excitation wavelengths at 780–1,100 nm. Accordingly, they may be utilized as potential precursor candidates to the active-core structures of photosensitizing nanodrugs for 2γ-PDT in the biological optical window of 800–1,050 nm. Full article
(This article belongs to the Section Organic Chemistry)
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