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Two new alcohol glycosides, 1-O-β-d-glucopyranosyl-deoxypaeonisuffrone (1) and 9-O-β-d-apiofuranoyl-(1→6)-β-d-glucopyranosyl-xanthoarnol (2), together with eight known compounds (3–10), have been isolated from the dried roots of Paeonia intermedia C. A. Meyer. Their structures were mainly elucidated on the basis of ESIMS, one- and two-dimensional NMR techniques. Antibacterial activities of compounds 1–10 were evaluated, and compounds 9 and 10 showed antibacterial activities against Staphylococcus argenteus CMCC26003 and Escherichia coli CMCC44103. [ABSTRACT FROM AUTHOR]

Four new oxepine-containing pyrazinopyrimidine alkaloids, versicoxepines A − D (1 – 4), two quinolinone alkaloid analogs including 3-hydroxy-6-methoxy-4-phenylquinolin-2(1 H)-one (5) and 3-methoxy-6-hydroxy-4-phenylquinolin-2(1 H)-one (6) which were new naturally occurring compounds, together with two known compounds (7 and 8) were isolated from Aspergillus versicolor AS-212, an endozoic fungus isolated from the deep-sea coral Hemicorallium cf. imperiale , which was collected from the Magellan Seamounts in the Western Pacific Ocean. Their structures were determined by extensive analysis of the spectroscopic and X-ray crystallographic data as well as by chiral HPLC analysis, ECD calculation, and DP4+ probability prediction. Structurally, versicoxepines B and C (2 and 3) represent the first example of a new oxepine-containing pyrazinopyrimidine alkaloid whose cyclic dipeptide moiety is composed of the same type of amino acid (Val or Ile). Compound 5 displayed antibacterial activity against aquatic pathogens, Vibrio harveyi and V. alginolyticus , with MICs of 8 μg/mL. [Display omitted] • Four new oxepine-containing diketopiperazines were isolated from deep-sea coral-derived Aspergillus versicolor AS-212. • Chiral HPLC, ECD and DP4+, and X-ray diffraction were used for structure determination. • Compound 5 exhibited potent activities against aquatic- and plant-pathogenic microbes. [ABSTRACT FROM AUTHOR]

Dermatophytosis, which is caused mainly by genera of Trichophyton, Epidermophyton, and Microsporum, is a frequent dermatological problem in tropical and subtropical countries. Investigations were carried out in this study to evaluate the antidermatophytic activity of the stems, leaves, and seeds of Croton tiglium, one of the traditional medicine plants indigenous to Asia. Ethanolic extracts of the stems, leaves, and seeds of C. tiglium were prepared by cold soak or heat reflux methods. The antidermatophytic activities of the extracts were evaluated by disc diffusion and microdilution susceptibility assays against Trichophyton mentagrophytes, T. rubrum, and Epidermophyton floccosum. The active components in the extracts were analyzed and identified by GC-MS. All ethanolic extracts of C. tiglium showed some antifungal activities against the three dermatophytes. The ethanolic stem extract had the greatest inhibitory activities against T. mentagrophytes and E. floccosum with MICs at 0.16 mg/mL and had a lower activity against T. rubrum (MIC: 0.31 mg/mL). Oleic acid and hexadecanoic acid were found to be the major constituents in the stem extract that demonstrated strong antidermatophytic activities. The ethanolic extracts of stem or seed of C. tiglium exhibit strong antidermatophytic activities and, thus, could be considered for application on treating skin fungal infections after appropriate processing. [ABSTRACT FROM AUTHOR]

Background: Jasmonic acid (JA) and methyl jasmonate (MeJA) regulate plant development, resistance to stress, and insect attack by inducing specific gene expression. However, little is known about the mechanism of plant defense against herbivore attack at a protein level. Using a high-resolution 2-D gel, we identified 62 MeJA-responsive proteins and measured protein expression level changes. Results: Among these 62 proteins, 43 proteins levels were increased while 11 proteins were decreased. We also found eight proteins uniquely expressed in response to MeJA treatment. Data are available via ProteomeXchange with identifier PXD001793. The proteins identified in this study have important biological functions including photosynthesis and energy related proteins (38.4%), protein folding, degradation and regulated proteins (15.0%), stress and defense regulated proteins (11.7%), and redox-responsive proteins (8.3%). The expression levels of four important genes were determined by qRT-PCR analysis. The expression levels of these proteins did not correlate well with their translation levels. To test the defense functions of the differentially expressed proteins, expression vectors of four protein coding genes were constructed to express in-fusion proteins in E. coli. The expressed proteins were used to feed Ostrinia furnacalis, the Asian corn borer (ACB). Our results demonstrated that the recombinant proteins of pathogenesis-related protein 1 (PR1) and thioredoxin M-type, chloroplastic precursor (TRXM) showed the significant inhibition on the development of larvae and pupae. Conclusions: We found MeJA could not only induce plant defense mechanisms to insects, it also enhanced toxic protein production that potentially can be used for bio-control of ACB. [ABSTRACT FROM AUTHOR]

Purpose: To identify the secreted proteins of murine embryos grown in vitro. Methods: Two-cell mouse embryos ( n = 432) were randomly allocated to culture to the blastocyst stage in protein-free and in protein-supplemented (3 % BSA) media. Proteins were separated by SDS-PAGE; bands were visualized by coomassie staining, followed by in-gel trypsin digestion and liquid chromatography-tandem mass spectrometry. RT-PCR and confocal microscopy were used to confirm gene/protein expression in blastocysts. Results: Of all individually identified proteins, 34 and 23 were found in embryos cultured without and with BSA, respectively, and 20 were common. Identified proteins having an N-terminal secretory sequence or transmembrane domains located on the extracellular backbone were postulated as secreted proteins. Gene and protein expression for two selected molecules were confirmed. Functional analysis revealed over-represented processes related to lipid metabolism, cyclase activity, and cell adhesion/membrane functions. Conclusions: This study provided evidence to further characterize secreted proteins by mouse embryos grown from the 2-cell to the blastocyst stage in vitro. Because of homology between murine and human, these results may provide information to be translated to the clinical setting. [ABSTRACT FROM AUTHOR]

Peptide natural products show broad biological properties and are commonly produced by orthogonal ribosomal and nonribosomal pathways in prokaryotes and eukaryotes. To harvest this large and diverse resource of bioactive molecules, we introduce here natural product peptidogenomics (NPP), a new MS-guided genome-mining method that connects the chemotypes of peptide natural products to their biosynthetic gene clusters by iteratively matching de novo tandem MS (MSn) structures to genomics-based structures following biosynthetic logic. In this study, we show that NPP enabled the rapid characterization of over ten chemically diverse ribosomal and nonribosomal peptide natural products of previously unidentified composition from Streptomycete bacteria as a proof of concept to begin automating the genome-mining process. We show the identification of lantipeptides, lasso peptides, linardins, formylated peptides and lipopeptides, many of which are from well-characterized model Streptomycetes, highlighting the power of NPP in the discovery of new peptide natural products from even intensely studied organisms. [ABSTRACT FROM AUTHOR]

During bacterial cannibalism, a differentiated subpopulation harvests nutrients from their genetically identical siblings to allow continued growth in nutrient-limited conditions. Hypothesis-driven imaging mass spectrometry (IMS) was used to identify metabolites active in a Bacillus subtilis cannibalism system in which sporulating cells lyse nonsporulating siblings. Two candidate molecules with sequences matching the products of skfA and sdpC, genes for the proposed cannibalistic factors sporulation killing factor (SKF) and sporulation delaying protein (SDP), respectively, were identified and the structures of the final products elucidated. SKF is a cyclic 26-amino acid (aa) peptide that is posttranslationally modified with one disulfide and one cysteine thioether bridged to the α-position of a methionine, a posttranslational modification not previously described in biology. SDP is a 42-residue peptide with one disulfide bridge. In spot test assays on solid medium, overproduced SKF and SDP enact a cannibalistic killing effect with SDP having higher potency. However, only purified SDP affected B. subtilis cells in liquid media in fluorescence microscopy and growth assays. Specifically, SDP treatment delayed growth in a concentration-dependent manner, caused increases in cell permeability, and ultimately caused cell lysis accompanied by the production of membrane tubules and spheres. Similarly, SDP but not SKF was able to inhibit the growth of the pathogens Staphylococcus aureus and Staphylococcus epidermidis with comparable IC50 to vancomycin. This investigation, with the identification of SKF and SDP structures, highlights the strength of IMS in investigations of metabolic exchange of microbial colonies and also demonstrates IMS as a promising approach to discover novel biologically active molecules. [ABSTRACT FROM AUTHOR]

Covering: up to June 2009 [ABSTRACT FROM AUTHOR]

Paenibacillus polymyxa is a beneficial bacterium for plant health. P. polymyxa TP3 exhibits antagonistic activity toward Botrytis cinerea and alleviates gray mold symptoms on the leaves of strawberry plants. Moreover, suppression of gray mold on the flowers and fruits of strawberry plants in field trials, including vegetative cells and endospores, was demonstrated, indicating the potential of strain TP3 as a biological control agent. To examine the anti-B. cinerea compounds produced by P. polymyxa TP3, we performed matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and fusaricidin-corresponding mass spectra were detected. Moreover, fusaricidin-related signals appeared in imaging mass spectrometry of TP3 when confronted with B. cinerea. By using liquid chromatography mass spectrometry-based molecular networking approach, we identified several fusaricidins including a new variant of mass/charge ratio 917.5455 with serine in the first position of the hexapeptide. Via advanced mass spectrometry and network analysis, fusaricidin-type compounds produced by P. polymyxa TP3 were efficiently disclosed and were presumed to play roles in the antagonism against gray mold pathogen B. cinerea. [ABSTRACT FROM AUTHOR]

The article presents a study on the use of acyl dye as a transfer agent to be applied in the immunoaffinity fluorescent (IAF) tag. The study intends to provide solution pertaining to the existing problems in the advancement of drugs. The mass spectral method was used in the study to be able to determine the site of dye transfer to actin.

Pinolenic acid is a polyunsaturated fatty acid present only in Pinus koraiensis Sieb. et Zucc seed oil. In order to solve the structural instability problem of polyunsaturated fatty acids, pinolenic acid of P. koraiensis seed oil was effectively isolated and purified by the integrated strategy of ethyl esterification followed by urea inclusion for the first time. Under the optimal conditions after the Box-Benhnken Design experimental, ethyl pinolenate with high purity 94.95% could be obtained, and the average content of PNAEE can still reach 86.18%. Then ethyl pinolenate was characterized by Gas chromatography-mass spectrometry, Fourier transform infrared, and Nuclear magnetic resonance spectra, results showed that ethyl pinolenate was successfully prepared. In addition, the hypolipidemic activity of ethyl pinolenate had been tested in vivo and showed that ethyl pinolenate had obvious hypolipidemic activity. The new strategy for high purity ethyl pinolenate production from P. koraiensis seed oil possesses great potential in food healthy field in the future. Diagram 1. The schematic synthesis process of PNAEE and its hypolipidemic activity evaluation. [Display omitted] [ABSTRACT FROM AUTHOR]

Traditional Chinese medicine (TCM) has been applied to improve human health for millennia. In the TCM system, "medicinal property" ( yao xing; hot and cold properties) is a core concept used to describe the influences of medicinal materials on human physiological conditions, and metabolites are believed to be one of the major ingredients of TCMs that affect their medicinal property. However, due to a lack of comprehensive analyses of TCM metabolomes, information about the relationships between TCM metabolite composition and medicinal property remains limited. In this pilot study, a mass spectral molecular networking-based platform was established and applied to systematically profile the metabolome of 24 TCMs with various medicinal properties. The molecular networks were built based on the liquid chromatography-tandem mass spectrometry (LC-MS/MS) data from 50% EtOH extracts of 24 TCMs. The results showed that various classes of metabolites were clustered in the molecular networks, and the potential medicinal propertyassociated molecular families were filtered by screening the medicinal property and the diversity of TCM sources. For example, some specific types of flavonoids were identified in the representative cold-property (han xing) molecular families. In contrast, due to the limited sample size, the representative and universal hot-property (re xing) molecular family has not been well revealed. In summary, this study provides methodology and information on the potential relationships between the metabolite composition and the concept of medicinal property in TCM. Furthermore, the results can serve as a foundation for mass spectral molecular networking-based analysis of TCM metabolomes, facilitating TCM research and development. [ABSTRACT FROM AUTHOR]

Abstract: Many microbes can be cultured as single-species communities. Often, these colonies are controlled and maintained via the secretion of metabolites. Such metabolites have been an invaluable resource for the discovery of therapeutics (e.g. penicillin, taxol, rapamycin, epothilone). In this article, written for a special issue on imaging mass spectrometry, we show that MALDI-imaging mass spectrometry can be adapted to observe, in a spatial manner, the metabolic exchange patterns of a diverse array of microbes, including thermophilic and mesophilic fungi, cyanobacteria, marine and terrestrial actinobacteria, and pathogenic bacteria. Dependent on media conditions, on average and based on manual analysis, we observed 11.3 molecules associated with each microbial IMS experiment, which was split nearly 50:50 between secreted and colony-associated molecules. The spatial distributions of these metabolic exchange factors are related to the biological and ecological functions of the organisms. This work establishes that MALDI-based IMS can be used as a general tool to study a diverse array of microbes. Furthermore the article forwards the notion of the IMS platform as a window to discover previously unreported molecules by monitoring the metabolic exchange patterns of organisms when grown on agar substrates. This article is part of a Special Issue entitled: Imaging Mass Spectrometry: A User’s Guide to a New Technique for Biological and Biomedical Research. [Copyright &y& Elsevier]

Here, we described the discovery of anti-infective agent arylomycin and its biosynthetic gene cluster in an industrial daptomycin producing strain Streptomyces roseosporus. This was accomplished via the use of MALDI imaging mass spectrometry (IMS) along with peptidogenomic approach in which we have expanded to short sequence tagging (SST) described herein. Using IMS, we observed that prior to the production of daptomycin, a cluster of ions (1-3) was produced by S. roseosporus and correlated well with the decreased staphylococcal cell growth. With a further adopted SST peptidogenomics approach, which relies on the generation of sequence tags from tandem mass spectrometric data and query against genomes to identify the biosynthetic genes, we were able to identify these three molecules (1-3) to arylomycins, a class of broad-spectrum antibiotics that target type I signal peptidase. The gene cluster was then identified. This highlights the strength of IMS and MS guided genome mining approaches in effectively bridging the gap between phenotypes, chemotypes, and genotypes. [ABSTRACT FROM AUTHOR]

Inductively coupled plasma-mass spectrometry (ICP-MS) is one of the most powerful techniques for multiplex nucleotide assay owing to the virtue of the high resolution of multiple-elements' mass to charge ratio, in a mass spectrum. Here, a small sized (less than 20 nm) noble-metal nanoparticle labelled ICP-MS (NP-ICP-MS) is proposed for high-throughput microRNA (miRNA) determination. Three miRNA targets – miR-486-5p, miR-221, and miR-21 – in serum, were distinguished by single-stranded DNA (ssDNA) probes labelled with a small sized noble-metal nanoparticle – silver nanoparticles (AgNPs), platinum nanoparticles (PtNPs), and gold nanoparticles (AuNPs). The counting isotopes ion intensity per second (CPS) of the noble-metal label versus internal standard isotope intensity of 115In and 209Bi, exhibited good linearity in the range 0.25 pM to 100 pM with correlation coefficients (R2) of 0.9680, 0.9305, and 0.9418. The specific sandwich-type miRNA assay using the sensitive NP-ICP-MS readout pushed the detection limits down to 0.18 pM for miR-221, 0.23 pM for miR-486-5p, and 0.22 pM for miR-21. And the relative standard deviations (RSDs) for 10 pM target miRNA were less than 3.7%. This work promises a potential ultrasensitive ICP-MS bioassay of multiplex miRNA biomarkers for clinical serum diagnosis. [ABSTRACT FROM AUTHOR]

SUMMARY: Imaging mass spectrometry (IMS) is a powerful technique that enables analysis of various molecular species at a high spatial resolution with low detection limits. In contrast to the matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) approach, surface‐assisted laser desorption/ionization (SALDI) can be more effective in the detection of small molecules due to the absence of interfering background signals in low m/z ranges. We developed a functionalized TiO2 nanowire as a solid substrate for IMS of low‐molecular‐weight species in plant tissues. We prepared TiO2 nanowires using an inexpensive modified hydrothermal process and subsequently functionalized them chemically with various silane analogs to overcome the problem of superhydrophilicity of the substrate. Chemical modification changed the selectivity of imprinting of samples deposited on the substrate surface and thus improved the detection limits. The substrate was applied to image distribution of the metabolites in very fragile specimens such as the petal of Catharanthus roseus. We observed that the metabolites are distributed heterogeneously in the petal, which is consistent with previous results reported for the C. roseus plant leaf and stem. The intermediates corresponding to the biosynthesis pathway of some vinca alkaloids were clearly shown in the petal. We also performed profiling of petals from five different cultivars of C. roseus plant. We verified the semi‐quantitative capabilities of the imprinting/imaging approach by comparing results using the LC‐MS analysis of the plant extracts. This suggested that the functionalized TiO2 nanowire substrate‐based SALDI is a powerful technique complementary to MALDI‐MS. Significance Statement: We developed a functionalized TiO2 nanowire as a solid substrate for surface‐assisted laser desorption/ionization imaging mass spectrometry of low‐molecular‐weight species in very fragile specimens such as the petal. Using this approach, we observed that some of the vinca alkaloids in the petal of Catharanthus roseus are distributed heterogeneously, and moreover we were able to detect some of their intermediates corresponding to the biosynthesis pathway. [ABSTRACT FROM AUTHOR]

Objective. Coronary heart disease (CHD) has been regarded as a serious and common disease in the modern society. This study aims to investigate the effect of Granule of BU-XIN RUAN-MAI (BXRM) on angina pectoris of coronary heart disease and to explore the molecular mechanisms underlying Granule of BU-XIN RUAN-MAI-mediated protective activity against this disease. Methods. The effects of Granule of BU-XIN RUAN-MAI on clinical symptoms of patients' angina were indicated by hemorheology indicators including high shear of blood viscosity, low shear of blood viscosity, plasma viscosity, erythrocyte rigidity index, D-D dimer, fibrinogen content, and lipid content. The effects of Granule of BU-XIN RUAN-MAI on isoprenaline-induced myocardial cell injury were determined by conducting H&E staining and by performing ELISA to examine the serum content of MDA, SOD, Na+/K+-ATPase, cAMP, and the content of inflammatory factors in isoprenaline-induced rats. Meanwhile, western blot and real time PCR were used to determine the expression of genes involved in oxidation and energy metabolism, and real time PCR was also used for determination of miR-542-3p expression. Luciferase reporter assay was conducted to test the binding sites of miR-542-3p on GABARAP 3′UTR. The chemical compositions of Granule of BU-XIN RUAN-MAI were determined by liquid LC-QTOF-MS. Results. Granule of BU-XIN RUAN-MAI significantly attenuated the clinical symptoms of patients' angina by improving the patients' heart rate and by decreasing the level of hemorheology indicators and also by reducing the serum content of TC, TG, LDL, and elevated HDL content. H&E staining demonstrated that Granule of BU-XIN RUAN-MAI ameliorated the myocardial ischemia in a dose-dependent manner. Besides, Granule of BU-XIN RUAN-MAI downregulated serum MDA content and upregulated the content of SOD, Na+/K+-ATPase, and cAMP in isoprenaline-induced rats. Granule of BU-XIN RUAN-MAI significantly improved oxidation stress by increasing PPARα expression, and it inhibited inflammation by downregulating expression and contents of IL-6, IL-1β, and TNF-α. Then, Granule of BU-XIN RUAN-MAI-containing serum increased the SOD content, and reduced the MDA content in angiotensin II-stimulated HUVEC cells. The granule of BU-XIN RUAN-MAI-containing serum obviously downregulated protein expressions of P40phox, P47phox, and P67phox in plasma membrane, and it significantly increased protein levels of P40phox, P47phox, and P67phox in the cytoplasm of HUVEC cells. Furthermore, GABARAP was reduced in heart tissues of ISO-induced rats and in angiotensin II-stimulated cell lines, and GABARAP was required for the inhibitory activity of Granule of BU-XIN RUAN-MAI on oxidation and inflammation in vivo and in vivo. GABARAP could be upregulated by Granule of BU-XIN RUAN-MAI by inhibiting the expression of miR-542-3p, which may significantly enhance oxidation and inflammation by targeting GABARAP in cardiomyocytes. Moreover, the silencing of GABARAP could obviously reverse the granule of BU-XIN RUAN-MAI-mediated protective activity against coronary heart disease, and interfering GABARAP expression also could partly block the anti-miR-542-3p-controlled oxidation and inflammation in cardiomyocytes. Besides, salidroside, loganin, and polydatin were the main compounds of granules of BU-XIN RUAN-MAI. Conclusion. Granule of BU-XIN RUAN-MAI is an excellent prescription for treatment of coronary heart disease by suppressing inflammation and NAPDH-mediated oxidative stress. The miR-542-3p/GABARAP axis is required for Granule of BU-XIN RUAN-MAI, exhibiting its protective activity against the pectoris of coronary heart disease. [ABSTRACT FROM AUTHOR]

In the present work, a novel infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) was developed for rapid determination of the volatile components in green tea. The extraction parameters such as fiber type, sample amount, infrared power, extraction time, and infrared lamp distance were optimized by orthogonal experimental design. Under optimum conditions, a total of 82 volatile compounds in 21 green tea samples from different geographical origins were identified. Compared with classical water-bath heating, the proposed technique has remarkable advantages of considerably reducing the analytical time and high efficiency. In addition, an effective classification of green teas based on their volatile profiles was achieved by partial least square-discriminant analysis (PLS-DA) and hierarchical clustering analysis (HCA). Furthermore, the application of a dual criterion based on the variable importance in the projection (VIP) values of the PLS-DA models and on the category from one-way univariate analysis (ANOVA) allowed the identification of 12 potential volatile markers, which were considered to make the most important contribution to the discrimination of the samples. The results suggest that IRAE-HS-SPME/GC-MS technique combined with multivariate analysis offers a valuable tool to assess geographical traceability of different tea varieties. [ABSTRACT FROM AUTHOR]

Mass spectrometry (MS) interfacing technology provides the means for incorporating microfluidic processing with post MS analysis. In this study, we propose a simple piezo-ring-on-chip microfluidic device for the controlled spraying of MALDI-MS targets. This device uses a low-cost, commercially-available ring-shaped piezoelectric acoustic atomizer (piezo-ring) directly integrated into a polydimethylsiloxane microfluidic device to spray the sample onto the MS target substrate. The piezo-ring-on-chip microfluidic device's design, fabrication, and actuation, and its pulsatile pumping effects were evaluated. The spraying performance was examined by depositing organic matrix samples onto the MS target substrate by using both an automatic linear motion motor, and manual deposition. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) was performed to analyze the peptide samples on the MALDI target substrates. Using our technique, model peptides with 10−6 M concentration can be successfully detected. The results also indicate that the piezo-ring-on-chip approach forms finer matrix crystals and presents better MS signal uniformity with little sample consumption compared to the conventional pipetting method. [ABSTRACT FROM AUTHOR]

Nanoscale silicon surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is an emerging matrix-free, highly sensitive MS analysis method. An important challenge in using nanoscale silicon SALDI-MS analysis is the aging and stability of silicon after storage in various environments. No proper nanoscale silicon SALDI-MS activation procedure has been reported to solve this issue. This study investigated the sensitivity, wettability, and surface oxidation behavior of nanoscale silicon surface SALDI-MS in a room, an inert gas atmosphere, and a vacuum environment. A simple vacuum oven desiccation was proposed to activate the SALDI-MS surface, and the limit of detection was further enhanced 1000 times to a 500 attomole level using this approach. The long-term stability and desorption/ionization mechanism were also investigated. [ABSTRACT FROM AUTHOR]

Single cell analysis has become an important field of research in recent years reflecting the heterogeneity of cellular responses in biological systems Here we demonstrate a new method, based on laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), which can quantify in situ gold nanoparticles (Au NPs) in single cells. Dried residues of picoliter droplets ejected by a commercial inkjet printer were used to simulate matrix-matched calibration standards. The gold mass in simile cells exposed to 100 nM NIST Au NPs (Reference material 8012, 30 nm) for 4 h showed a log-normal distribution, ranging from 1.7 to 72 fg Au per cell, which s approximately corresponds to 9 to 370 Au NPs per cell. The average result from 70 single cells (15±13 fg Au per cell) was in good agreement with the result from an aqua regia digest solution of 1.2 × 106 cells (18 ± 1 fg Au per cell). The limit of quantification was 1.7 fg Au. This paper demonstrates the great potential of LA-ICPMS for single cell analysis and the beneficial study of biological responses to metal drugs or NPs at the single cell level [ABSTRACT FROM AUTHOR]

Two new flavonols, 6-p-hydroxybenzyl kaempferol (1) and 6-p-hydroxybenzyl quercetin (2), together with six known compounds were isolated from the roots of Cudrania cochinchinensis and their structures elucidated on the basis of spectroscopic methods. Their antioxidant capacities were evaluated by 1,1-diphenyl-2-picryl-hydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical-scavenging assays. The results suggested that compounds 2, 4, and 7 showed significant radical-scavenging activities. [ABSTRACT FROM AUTHOR]

Covering: up to the end of September 2013 Microorganisms are a plentiful resource for natural products research. Traditionally, natural products discovery from microbial sources depends on the screening of target-mediated inhibition. The natural products identified through this strategy usually correlate to significant microbial phenotypes. However, the target-mediated transcriptions deduced from low concentrations of natural products sometimes do not generate an obvious phenotype. The better understanding of the true biological roles of those microbial natural products will permit the application of rational approaches to the more effective exploitation of their use. Imaging mass spectrometry (IMS) has been developed and applied in many fields for decades. However, the applications of IMS on microbial natural products research have just been recently reported. IMS is one of few tools capable of revealing both phenotype and relevant and irrelevant chemotypes of microorganisms. In this review, we summarize the latest applications of IMS technologies. The challenges and prospect of improvement and application of IMS to microbial natural products research are discussed as well. [ABSTRACT FROM AUTHOR]

An immunomodulatory peptide was isolated from bovine placenta water-soluble extract and purified by consecutive chromatography on DEAE Sepharose CL-6B, Sephadex G-25, and Sephasil C18 column using lymphocyte proliferation assay to identify the active fractions. The immunomodulatory peptide showed a dose-dependent stimulating effect on lymphocyte proliferation. The isoelectric point of the immunodulatory peptide was determined to be 3.82 by capillary isoelectric focusing electrophoresis. The molecular mass of the immunomodulatory peptide was determined to be 2133.52 Da by mass spectrometry. The first 10 amino acid sequence of the immunomodulatory peptide was Tyr-X-Phe-Leu-Gly-Leu-Pro-Gly-X-Thr. This immunomodulatory peptide showed no significant homology with other immunomodulatory peptides. Additionally, it was thermostable, retaining about 60% of immune activity after incubating at 80°C for 30 min. [ABSTRACT FROM AUTHOR]

A new method of single-drop microextraction combined with low-temperature electrothermal vaporization (LTETV)-ICPMS was proposed for the determination of trace Be, Co, Pd, and Cd with benzoylacetone (BZA) as both extractant and chemical modifier. Several factors that influence the microextraction efficiency, such as sample flow rate, microdrop volume, and extraction time, were investigated and the optimized microextraction conditions were established. Be, Co, Pd, and Cd in the postextraction organic phase were directly determined by LTETV-ICPMS with the use of BZA as chemical modifier. The chemical modification of BZA in LTETV-ICPMS was studied, and the factors affecting the formation of chelates and vaporization/transportation of chelates were investigated. Under the optimized conditions, the detection limits of the method were 0.12, 0.99, 1.5, and 0.27 pg/mL for Be, Co, Pd, and Cd, and the relative standard deviations for 0.1 ng/mL Be, Co, Pd, and Cd were 16, 14, 14, and 11%, respectively. After 10 min of extraction, the enrichment factors were 160 (Be), 125 (Co), 40 (Pd), and 180 (Cd). The proposed method was applied to the determination of trace Be, Co, Pd, and Cd in biological reference materials, and the determined values were in good agreement with the certified values. [ABSTRACT FROM AUTHOR]

A novel disintegrin, jerdonin, was purified from the Trimeresurus jerdonii venom by means of gel filtration and reverse phase high pressure liquid chromatography. Its coding cDNA was also isolated from the venom gland. The jerdonin coding cDNA is part of a precursor composed of proprotein, metalloproteinase, and disintegrin domains. From the deduced amino acid sequence, jerdonin is composed of 71 amino acid residues including 12 cysteines and the tripeptide sequence Arg-Gly-Asp (RGD), a well-known characteristic of the disintegrin family. Molecular mass of jerdonin was determined to be 7483 Da by matrix-assisted laser desorption ionization time of flight mass spectrometry. Jerdonin inhibited ADP- and collagen-induced human platelet aggregation with IC50 of 220 and 240 nM, respectively. In vivo, jerdonin inhibited the growth of subcutaneously inoculated B16 solid tumor in C57BL/6 mice and improved the survival time of the tumor-bearing mice. [Copyright &y& Elsevier]

A robust and convenient research strategy integrating state-of-the-art analytical techniques is needed to efficiently discover novel compounds from marine microbial resources. In this study, we identified a series of amino-polyketide derivatives, vitroprocines A-J, from the marine bacterium Vibrio sp. QWI-06 by an integrated approach using imaging mass spectroscopy and molecular networking, as well as conventional bioactivity-guided fractionation and isolation. The structure-activity relationship of vitroprocines against Acinetobacter baumannii is proposed. In addition, feeding experiments with 13C-labeled precursors indicated that a pyridoxal 5′-phosphate-dependent mechanism is involved in the biosynthesis of vitroprocines. Elucidation of amino-polyketide derivatives from a species of marine bacteria for the first time demonstrates the potential of this integrated metabolomics approach to uncover marine bacterial biodiversity. [ABSTRACT FROM AUTHOR]