15 research outputs found

    Chemical constituents from <i>Sambucus williamsii</i> Hance fruits and hepatoprotective effects in mouse hepatocytes

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    <p>Chemical investigation of Chinese folk medicine <i>Sambucus williamsii</i> Hance has resulted in the isolation and characterisation of seventeen compounds from the <i>n</i>-BuOH extract of its fruits, including two new phenylethanoid glycosides and fifteen known compounds. Structures of new compounds were elucidated primarily on the basis of their extensive spectroscopic data including 2D NMR. In addition, the <i>n</i>-BuOH extract from the fruits of <i>S. williamsii</i> was found to show a protective effect on D-galactosamine (D-GalN)-induced cytotoxicity in primary cultured mouse hepatocytes. So the hepatoprotective effects of principal constituents from it were tested by MTT assays. The results showed that Compounds <b>13</b>, <b>16</b> and <b>17</b> displayed hepatoprotective effects.</p

    First Quantification of Imidazoles in Ambient Aerosol Particles: Potential Photosensitizers, Brown Carbon Constituents, and Hazardous Components

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    Imidazoles are widely discussed in recent literature. They have been studied as a secondary product of the reaction of dicarbonyls with nitrogen containing compounds in a number of laboratory studies, potentially acting as photosensitizers triggering secondary organic aerosol growth and are forming constituents of light absorbing brown carbon. Despite the knowledge from laboratory studies, no quantitative information about imidazoles in ambient aerosol particles is available. Within the present study, five imidazoles (1-butylimidazole, 1-ethylimidazole, 2-ethylimidazole, imidazol-2-carboxaldehyde, and 4(5)-methylimidazole) were successfully identified and quantified for the first time in ambient aerosol samples from different environments in Europe and China. Their concentrations range between 0.2 and 14 ng/m<sup>3</sup>. 4(5)-Methylimidazole was found to be the most abundant imidazole. The occurrence of imidazoles seems to be favored at sites with strong biomass burning influence or connected to more polluted air masses. No connection was found between aerosol particle pH and imidazole concentration. Our work corroborates the laboratory studies by showing that imidazoles are present in ambient aerosol samples in measurable amounts. Moreover, it further motivates to explore the potential photosensitizing properties of small alkyl-substituted imidazoles

    Metabolic Analysis Reveals Altered Long-Chain Fatty Acid Metabolism in the Host by Huanglongbing Disease

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    <i>Candidatus</i> Liberibacter asiaticus (<i>C</i>Las) is the presumed causal agent of Huanglongbing, one of the most destructive diseases in citrus. However, the lipid metabolism component of host response to this pathogen has not been investigated well. Here, metabolic profiling of a variety of long-chain fatty acids and their oxidation products was first performed to elucidate altered host metabolic responses of disease. Fatty acid signals were found to decrease obviously in response to disease regardless of cultivar. Several lipid oxidation products strongly correlated with those fatty acids were also consistently reduced in the diseased group. Using a series of statistical methods and metabolic pathway mapping, we found significant markers contributing to the pathological symptoms and identified their internal relationships and metabolic network. Our findings suggest that the infection of <i>C</i>Las may cause the altered metabolism of long-chain fatty acids, possibly leading to manipulation of the host’s defense derived from fatty acids

    Dual-Readout Fluorescent Assay of Protein Kinase Activity by Use of TiO<sub>2</sub>‑Coated Magnetic Microspheres

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    A simple, highly sensitive, and dual-readout fluorescent assay is developed for the detection of protein kinase activity based on the specific recognition utility of TiO<sub>2</sub>-coated Fe<sub>3</sub>O<sub>4</sub>/SiO<sub>2</sub> magnetic microspheres (TMSPs) for kinase-induced phosphopeptides. When the fluorophore-labeled substrate peptides are phosphorylated by the kinase reaction, they can bind specifically to the TiO<sub>2</sub> layer of TMSPs by means of phosphate groups, resulting in fluorophore enrichment on the TMSP surfaces. The accumulated fluorophores on the TMSPs are proportional to the kinase activity, and the fluorescence signal readout could be run through either direct fluorescent imaging of the TMSPs or measurement of the fluorescence intensity by simply detaching the fluorescent phosphopeptides into the solution. The TMSPs exhibit extremely high selectivity for capturing phosphorylated peptides over the nonphosphorylated ones, resulting in an ultrahigh fluorescence signal-to-background ratio of 42, which is the highest fluorescence change thus far in fluorescent assays for detection of protein kinase activities. Therefore, the proposed fluorescent assay presents high sensitivity, low detection limit of 0.1 milliunit/μL, and wide dynamic range from 0.5 milliunit/μL to 0.5 unit/μL with protein kinase A (PKA) as a model target. Moreover, the TMSP-based fluorescent assay can simultaneously quantify multiple kinase activities with their specific peptides labeled with different dyes. This new strategy is also successfully applied to monitoring drug-triggered PKA activation in cell lysates. Therefore, the TMSP-based fluorescent assay is very promising in high-throughput screening of kinase inhibitors and in highly sensitive detection of kinase activity, and thus it is a valuable tool for development of targeted therapy, clinical diagnosis, and studies of fundamental life science

    Asymmetric Biodegradable Microdevices for Cell-Borne Drug Delivery

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    Use of live cells as carriers for drug-laden particulate structures possesses unique advantages for drug delivery. In this work, we report on the development of a novel type of particulate structures called microdevices for cell-borne drug delivery. The microdevices were fabricated by soft lithography with a disklike shape. Each microdevice was composed of a layer of biodegradable thermoplastic such as poly­(lactic-<i>co</i>-glycolic acid). One face of the thermoplastic layer was covalently grafted with a cell-adhesive polyelectrolyte such as poly-l-lysine. This asymmetric structure allowed the microdevices to bind to live cells through bulk mixing without causing cell aggregation. Moreover, the cell–microdevice complexes were largely stable, and the viability and proliferation ability of the cells were not affected by the microdevices over a week. In addition, sustained release of a mock drug from the microdevices was demonstrated. This type of microdevice promises to be clinically useful for sustained intravascular drug delivery

    Xanthones isolated from <i>Gentianella acuta</i> and their protective effects against H<sub>2</sub>O<sub>2</sub>-induced myocardial cell injury

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    <p>In the present study, two new xanthones, (5′S,8′S)-1,3,5,8-tetrahydroxyxanthone(7→2′)-1,3,5,8-tetrahydroxy-5′,6′,7′,8′-tetrahydroxanthone (<b>1</b>), 5-hydroxy-3,4,6-trimethoxyxanthone-1-<i>O</i>-<i>β</i>-D-glucopyranoside (<b>2</b>), and eight known xanthones (<b>3–10</b>) were isolated from the whole plants of <i>Gentianella acuta</i>. Their structures were identified by the spectroscopic analyses (HR-ESI-MS, and 1D and 2D NMR). Meanwhile, cell-protective effects against H<sub>2</sub>O<sub>2</sub>-induced H9c2 cardiomyocyte injury and cytotoxic activities of compounds <b>1–10</b> were also determined.</p

    Profiling and identification of chlorogenic acid metabolites in rats by ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometer

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    <p>1. Chlorogenic acids (CGAs), one kind of major bioactive constituents isolated from <i>Flos Lonicera Japonica</i>, possess many biological activities, such as antibacterial, antioxidant and antiviral activities. In this study, we established an efficient strategy using ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap MS) to profile the <i>in vivo</i> metabolic fate of CGAs in rat urine and plasma.</p> <p>2. The extract from <i>Flos Lonicera Japonica</i> was orally administrated to Sprague-Dawley (SD) rats at a dose of 1000 mg/kg body weight. Then, a combination of various post-acquisition data mining methods, including high-resolution extracted ion chromatogram (HREIC) and multiple mass defect filters (MMDFs) and diagnostic product ions (DPIs), were adopted to characterize the known and unknown CGA metabolites in SD rats.</p> <p>3. As a result, a total of 68 CGA metabolites were unambiguously or tentatively screened and characterized. These metabolites, including 18 prototype compounds and 50 metabolites, were deduced to be yielded <i>via</i> methylation, hydrogenation, demethylation, dehydration, sulfate conjugation, glucuronide conjugation, glycosylation conjugation and their composite reactions, which mainly occurred to caffeoylquinic acids, dicaffeoylquinic acids, <i>p</i>-coumaroylquinic acids and feruloylquinic acids.</p> <p>4. In conclusion, this study profiled CGA metabolites, which are useful in understanding the <i>in vivo</i> metabolic fate, effective forms, and pharmacological and toxic actions of CGAs.</p

    Research Data for A case series of constrictive pericarditis and suggested echocardiographic diagnostic criteria

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    Research Data for A case series of constrictive pericarditis and suggested echocardiographic diagnostic criteria by Junfang Li, Rong Li, Guangting Cheng, Changhong Lu, Weigang Liu, Dongmei Sun, Xue Li and Zhibin Wang in Journal of International Medical Research</p

    Catalase-Laden Microdevices for Cell-Mediated Enzyme Delivery

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    Enzymes have been used to treat various human diseases and traumas. However, the therapeutic utility of free enzymes is impeded by their short circulation time, lack of targeting ability, immunogenicity, and inability to cross biological barriers. Cell-mediated drug delivery approach offers the unique capability to overcome these limitations, but the traditional cell-mediated enzyme delivery techniques suffer from drawbacks such as risk of intracellular degradation of and low loading capacity for the payload enzyme. This article presents the development of a novel cell-mediated enzyme delivery technique featuring the use of micrometer-sized disk-shaped particles termed microdevices. The microdevices are fabricated by layer-by-layer assembly and soft lithography with catalase being used as a model therapeutic enzyme. The amount of catalase in the microdevices can be controlled with the number of catalase layers. Catalase in the microdevices is catalytically active, and active catalase is slowly released from the microdevices. Moreover, cell–microdevice complexes are produced by attaching the catalase-laden microdevices to the external surface of both K562 cells and mouse embryonic stem cells. This technique is potentially applicable to other enzymes and cells and promises to be clinically useful

    Efficient and Stable Pure Green All-Inorganic Perovskite CsPbBr<sub>3</sub> Light-Emitting Diodes with a Solution-Processed NiO<sub><i>x</i></sub> Interlayer

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    The perovskite-based optoelectronic applications always suffer from stability issues, due to the intrinsic chemical instability of the perovskite materials. Besides, poly­(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) is always utilized as an anode buffer layer in thin-film perovskite light-emitting diodes (PeLEDs), which may lead to stability issues due to the hygroscopic and acidic nature of PEDOT:PSS. In this paper, inorganic metal oxide NiO<sub><i>x</i></sub> is employed as a hole injection layer (HIL) and hole transport layer (HTL) to substitute detrimental PEDOT:PSS in all-inorganic PeLEDs. Then fully covered CsPbBr<sub>3</sub> polycrystalline films are fabricated by using a one-step spin-coating method based on nonstoichiometric and polymer-assisted perovskite precursor solutions. The optimized films not only have compact morphology but also have excellent photoluminescence quantum yield (PLQY). Encouragingly, by introducing a metal oxide NiO<sub><i>x</i></sub>, the CsPbBr<sub>3</sub> PeLEDs show a maximum luminance of 23 828 cd m<sup>–2</sup> and maximum current efficiency (CE) of 9.54 cd A<sup>–1</sup>, which lead to a 1.6-fold and 3.3-fold increase compared to the PeLEDs with a PEDOT:PSS HIL. Besides, the inorganic PeLEDs show high color purity with a full-width at half-maximum (fwhm) of only 16 nm. The combination of inorganic NiO<sub><i>x</i></sub> with inorganic perovskite also shows improved operation stability of devices, which paves the way for highly efficient all-inorganic PeLEDs
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