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Multilamellar bodies (MLBs) are membrane-bound cytoplasmic organelles of lysosomal origin. In some protozoa, they were considered as lipid storage secretory organelles and feasible participants in cell-to-cell communication. However, for Acanthamoeba castellanii, similar vesicles were indicated only as possible transmission vectors of several pathogenic bacteria without attributing them biological roles and activities. Since amoebae belonging to the genus Acanthamoeba are not only of environmental but also of clinical significance, it is of great importance to fully understand their physiology. Thus, determination of MLB lipid composition could partly address these questions. Because MLBs are secreted by amoebae as a result of bacteria digestion, the co-culture technique with the use of "edible" Klebsiella aerogenes was used for their production. Lipids obtained from The MLB fraction, previously purified from bacterial debris, were analyzed by high-performance thin-layer chromatography, gas chromatography coupled with mass spectrometry, and high-resolution mass spectrometry. Lipidomic analysis revealed that in MLBs, a very abundant lipid class was a non-phosphorous, polar glycerolipids, diacylglyceryl-O-(N,N,N)-trimethylhomoserine (DGTS). Since DGTSs are regarded as a source of nitrogen and fatty acids, MLBs can be considered as lipid storage organelles produced in stress conditions. Further, the identification of phytoceramides and possible new betaine derivatives indicates that MLBs might have a distinct bioactive potential. [ABSTRACT FROM AUTHOR]

Multilamellar bodies (MLBs) are membrane-bound cytoplasmic organelles of lysosomal origin. In some protozoa, they were considered as lipid storage secretory organelles and feasible participants in cell-to-cell communication. However, for Acanthamoeba castellanii, similar vesicles were indicated only as possible transmission vectors of several pathogenic bacteria without attributing them biological roles and activities. Since amoebae belonging to the genus Acanthamoeba are not only of environmental but also of clinical significance, it is of great importance to fully understand their physiology. Thus, determination of MLB lipid composition could partly address these questions. Because MLBs are secreted by amoebae as a result of bacteria digestion, the co-culture technique with the use of “edible” Klebsiella aerogenes was used for their production. Lipids obtained from The MLB fraction, previously purified from bacterial debris, were analyzed by high-performance thin-layer chromatography, gas chromatography coupled with mass spectrometry, and high-resolution mass spectrometry. Lipidomic analysis revealed that in MLBs, a very abundant lipid class was a non-phosphorous, polar glycerolipids, diacylglyceryl-O-(N,N,N)-trimethylhomoserine (DGTS). Since DGTSs are regarded as a source of nitrogen and fatty acids, MLBs can be considered as lipid storage organelles produced in stress conditions. Further, the identification of phytoceramides and possible new betaine derivatives indicates that MLBs might have a distinct bioactive potential.

In analyzing grapevine clones infected with grapevine red blotch associated virus, we identified a small number of isometric particles of approximately 30 nm in diameter from an enriched fraction of leaf extract. A dominant protein of 25 kDa was isolated from this fraction using SDS-PAGE and was identified by mass spectrometry as belonging to grapevine asteroid mosaic associated virus (GAMaV). Using a combination of three methods RNA-Seq, sRNA-Seq, and Sanger sequencing of RT- and RACE-PCR products, we obtained a full-length genome sequence consisting of 6719 nucleotides without the poly(A) tail. The virus possesses all of the typical conserved functional domains concordant with the genus Marafivirus and lies evolutionarily between citrus sudden death associated virus and oat blue dwarf virus. A large shift in RNA-Seq coverage coincided with the predicted location of the subgenomic RNA involved in coat protein (CP) expression. Genus wide sequence alignments confirmed the cleavage motif LxG(G/A) to be dominant between the helicase and RNA dependent RNA polymerase (RdRp), and the RdRp and CP domains. A putative overlapping protein (OP) ORF lacking a canonical translational start codon was identified with a reading frame context more consistent with the putative OPs of tymoviruses and fig fleck associated virus than with those of marafiviruses. BLAST analysis of the predicted GAMaV OP showed a unique relatedness to the OPs of members of the genus Tymovirus . [ABSTRACT FROM AUTHOR]

This article is focused on the seasonal variation in the contents of 5-methoxycanthin-6-one from the leaves of Zanthoxylum chiloperone (Rutaceae). Based on the pharmacological interest presented by 5-methoxycanthin-6-one, its seasonal variation in Z. chiloperone leaves was analysed in order to determine the best time for harvesting, optimising the 5-methoxycanthin-6-one content. The seasonal dynamics of canthinone alkaloids can be the key to improve the isolation from natural sustainable sources, such as leaves. Complementarily, this study describes the phytochemistry of leaf from this Ruraceae species. [ABSTRACT FROM AUTHOR]

Quantification of human hemoglobin (Hb) is essential for diagnosis of anemia, especially for screening for thalassemia and sickle cell disease. The main methods currently used for quantification of Hb, including spectrophotometry, fluorimetry, and electrochemical assays, are all based on the structural integrity of Hb, which could be affected by hemolysis and degradation. When used for disease screening, whole blood specimens cannot meet requirements for sample collecting, transport, and storage. Here, we report a novel MS-MS method for quantification of Hb from dried blood spots (DBS) by use of a triple-quadrupole mass spectrometer. Proteospecific peptides from α-globin chains were selected after tryptic digestion. The precursor → product ion transitions of representative peptides were studied to identify the best choice with regard to sensitivity and chromatographic properties. For quantification, stable isotope-labeled peptides were used as internal standards. The concentration of Hb in each sample was obtained by calculation on the basis of established equations. The precision of the method was within 15 % and accuracy was in the range −7 to 13.0 %. Compared with routine clinical results obtained by use of the automated hematology analyzer (AHA) assay, the correlation, r, was >0.993. When used for determination of anemia levels the sensitivity of the assay was 95.7 % and specificity 96.5 %. Our new approach for quantification of the concentration of Hb from DBS is feasible, and precision is acceptable. The method could be used for determination of anemia levels when screening for hemoglobin disorders. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The use of algae as a foodstuff is rapidly expanding worldwide from the East Asian countries, where they are also used for medical care. Harmala alkaloids (HAlk) are a family of bioactive compounds found in the extracts of some plants, including wakame ( Undaria pinnatifida), an edible marine invasive algae. HAlks are based on a characteristic β-carboline structure with at least one amino ionizable group. In this work, we report the successful separation of a mixture of six HAlks (harmine, harmaline, harmol, harmalol, harmane, and norharmane) by capillary electrophoresis ion-trap mass spectrometry (CE-IT-MS) in less than 8 min. Optimum separation in fused-silica capillaries and detection sensitivity in positive-ion mode were achieved using a background electrolyte (BGE) with 25 mmol L ammonium acetate (pH 7.8) and 10 % ( v/ v) methanol, and a sheath liquid with 60:40 ( v/ v) isopropanol-water and 0.05 % ( v/ v) formic acid. The separation method was validated in terms of linearity, limits of detection and quantification, repeatability, and reproducibility. Later, a sample pretreatment was carefully optimized to determine HAlks in commercial wakame samples with excellent recovery and repeatability. For the complex wakame extracts, the MS-MS fragmentation patterns of the different HAlks were useful to ensure a reliable identification. The complete procedure was validated using the standard-addition calibration method, determining matrix effects on the studied compounds. Harmalol, harmine, and harmaline were naturally present in the samples and were quantified at very low concentrations, ranging from 7 to 24 μg kg dry algae. [ABSTRACT FROM AUTHOR]

Hsp27—encoded by HspB1—is a member of the small heat shock proteins (sHsp, 12–43 kDa (kilodalton)) family. This protein is constitutively present in a wide variety of tissues and in many cell lines. The abundance of Hsp27 is highest in skeletal muscle, indicating a crucial role for muscle physiology. The protein identified as a beef tenderness biomarker was found at a crucial hub in a functional network involved in beef tenderness. The aim of this study was to analyze the proteins impacted by the targeted invalidation of HspB1 in the Tibialis anterior muscle of the mouse. Comparative proteomics using two-dimensional gel electrophoresis revealed 22 spots that were differentially abundant between HspB1-null mice and their controls that could be identified by mass spectrometry. Eighteen spots were more abundant in the muscle of the mutant mice, and four were less abundant. The proteins impacted by the absence of Hsp27 belonged mainly to calcium homeostasis (Srl and Calsq1), contraction (TnnT3), energy metabolism (Tpi1, Mdh1, PdhB, Ckm, Pygm, ApoA1) and the Hsp proteins family (HspA9). These data suggest a crucial role for these proteins in meat tenderization. The information gained by this study could also be helpful to predict the side effects of Hsp27 depletion in muscle development and pathologies linked to small Hsps.

Tandem mass spectrometry (MS-MS) is a generic term evoking techniques dedicated to structural analysis, detection or quantification of molecules based on dissociation of a precursor ion into fragments. Searching for the most informative fragmentation patterns has led to the development of a vast array of activation modes that offer complementary ion reactivity and dissociation pathways. Collisional activation of ions using atoms, molecules or surface resulting in unimolecular dissociation of activated ions still plays a key role in tandem mass spectrometry. The discovery of electron capture dissociation (ECD) and then the development of other electron-ion or ion/ion reaction methods, constituted a significant breakthrough, especially for structural analysis of large biomolecules. Similarly, photon activation opened promising new frontiers in ion fragmentation owing to the ability of tightly controlled internal energy deposition and easy implementation on commercial instruments. Ion activation by photons includes slow heating methods such as infrared multiple photon dissociation (IRMPD) and black-body infrared radiative dissociation (BIRD) and higher energy methods like ultra-violet photodissociation (UVPD) and electron photo detachment dissociation (EPD). EPD occurs after UV irradiation of multiply negatively charged ions resulting in the formation of oxidized radical anions. The present paper reviews the hypothesis regarding the mechanisms of electron photo-detachment, radical formation and direct or activated dissociation pathways that support the observation of odd and even electron product ions. Finally, the value of EPD as a complementary structural analysis tool is illustrated through selected examples of synthetic polymers, oligonucleotides, polypeptides, lipids, and polysaccharides. © 2013 Wiley Periodicals, Inc. Mass Spec Rev 33: 501-522, 2014. [ABSTRACT FROM AUTHOR]

The oxidation of the often used oxazine direct dye C.I. Direct Blue 106 (Direct Dye 106 ) in an aqueous solution (600 mg L-1) by ozonation was investigated. VIS spectra showed degradation of the oxazine groups in the initial Direct Dye 106 structure. The oxidation by-products, such as sulphate, nitrate, nitrite, chloride ions and phenolic compounds, were identified by MS-MS and the LC-MS analyses. After ozonation the wastewater containing the Direct Dye 106 showed no toxic characteristics, according to Daphnia magna test (24 h- EC50 > 75 %). [ABSTRACT FROM AUTHOR]

Copyright of Tekstil: Journal of Textile & Clothing Technology is the property of Croatian Association of Textile Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: The plant pathogenic and saprophytic fungus Fusarium avenaceum causes considerable in-field and post-field losses worldwide due to its infections of a wide range of different crops. Despite its significant impact on the profitability of agriculture production and a desire to characterize the infection process at the molecular biological level, no genetic transformation protocol has yet been established for F. avenaceum. In the current study, it is shown that F. avenaceum can be efficiently transformed by Agrobacterium tumefaciens mediated transformation. In addition, an efficient and versatile single step vector construction strategy relying on Uracil Specific Excision Reagent (USER) Fusion cloning, is developed. Results: The new vector construction system, termed USER-Brick, is based on a limited number of PCR amplified vector fragments (core USER-Bricks) which are combined with PCR generated fragments from the gene of interest. The system was found to have an assembly efficiency of 97% with up to six DNA fragments, based on the construction of 55 vectors targeting different polyketide synthase (PKS) and PKS associated transcription factor encoding genes in F. avenaceum. Subsequently, the ΔFaPKS3 vector was used for optimizing A. tumefaciens mediated transformation (ATMT) of F. avenaceum with respect to six variables. Acetosyringone concentration, co-culturing time, co-culturing temperature and fungal inoculum were found to significantly impact the transformation frequency. Following optimization, an average of 140 transformants per 106 macroconidia was obtained in experiments aimed at introducing targeted genome modifications. Targeted deletion of FaPKS6 (FA08709.2) in F. avenaceum showed that this gene is essential for biosynthesis of the polyketide/nonribosomal compound fusaristatin A. Conclusion: The new USER-Brick system is highly versatile by allowing for the reuse of a common set of building blocks to accommodate seven different types of genome modifications. New USER-Bricks with additional functionality can easily be added to the system by future users. The optimized protocol for ATMT of F. avenaceum represents the first reported targeted genome modification by double homologous recombination of this plant pathogen and will allow for future characterization of this fungus. Functional linkage of FaPKS6 to the production of the mycotoxin fusaristatin A serves as a first testimony to this. [ABSTRACT FROM AUTHOR]

Mass spectra were obtained to evaluate the use of numerous single-cation and dicationic ionic liquids as stationary liquid phases in GC/MS at high temperature. Background mass spectra and product ion mass spectra of several ions in the background spectrum were obtained. Fragmentation mechanisms were propounded, including the detailed fragmentation pathway of the 1,2-dimethyl-3-propylimidazole cation. The relation between temperature and the main signals in the mass spectra of ILs was studied. [ABSTRACT FROM AUTHOR]

Abstract: A straightforward methodology for the chromatographic separation and accurate mass identification of 100 pharmaceuticals including some of their degradation products was developed using liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/Q-TOF-MS). A table compiling the protonated or deprotonated exact masses for all compounds, as well as the exact mass of several fragment ions obtained by MS–MS is included. Excellent chromatographic separation was achieved by using 3.5μm particle size columns and a slow and generic 30-min gradient. Isobaric and isomeric compounds (same nominal mass and same exact mass, respectively) were distinguished by various methods, including chromatography separation, MS–MS fragmentation, and isotopic signal identification. Method reporting limits of detection ranged from 1 to 1000ng/L, after solid-phase extraction of 100mL aqueous samples. The methodology was successfully applied to the analysis of surface water impacted by wastewater effluent by identifying many of the pharmaceuticals and metabolites included in the list. Examples are given for some of the most unusual findings in environmental samples. This paper is meant to serve as a guide for those doing analysis of pharmaceuticals in environmental samples, by providing exact mass measurements of several well known, as well as newly identified and environmentally relevant pharmaceuticals in water samples. [Copyright &y& Elsevier]

High-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS-MS) is regarded as one of the most powerful techniques for separation and identification of proteins. Recently, much effort has been made to improve the separation capacity, detection sensitivity, and analysis throughput of micro- and nano-HPLC, by increasing column length, reducing column internal diameter, and using integrated techniques. Development of HPLC columns has also been rapid, as a result of the use of submicrometer packing materials and monolithic columns. All these innovations result in clearly improved performance of micro- and nano-HPLC for proteome research. [ABSTRACT FROM AUTHOR]

Abstract: Current strategies in the LC–MS analysis of pesticides and related compounds in environmental samples, fruits and vegetables, and biological samples mostly rely on the selection of appropriate precursor/product-ion combinations (transitions) for selected reaction monitoring (SRM), often based on automated parameter optimization and selection of the transition. Such a procedure does not require any information on the type of fragmentation reaction involved in the generation of the product ion from the selected precursor ion. However, such information does become important in untargeted screening for unknown contaminants in environmental and food samples, which are generally based on a combination of high-resolution mass spectrometry and (multistage) tandem mass spectrometry. With this in mind, the group-specific fragmentation behaviour has been studied for six classes of pesticides and herbicides, i.e., triazines, organophosphorous pesticides, phenylurea herbicides, carbamates, sulfonylurea herbicides, and chlorinated phenoxy acid herbicides. When relevant, some comparison was made between fragmentation of protonated molecules in MS–MS and of molecular ions generated by electron ionization in GC–MS. [Copyright &y& Elsevier]

Abstract: A novel ion mobility (IM)-surface-induced dissociation (SID)-mass spectrometer consisting of two independent time-of-flight (TOF) mass analyzers is described. The dual TOF instrument configuration facilitates high-throughput post-ionization separation and mass analysis of precursor and fragment ions, and the utility of 3D data acquisition is demonstrated for top-down proteomics by performing simultaneous acquisition of peptide mass maps and amino acid sequence determination. [Copyright &y& Elsevier]

Inorganic arsenite (As3+) and arsenate (As5+) are well-known poisons, and the toxicity of As3+ is about ten times that of As5+. In this study, a simple, rapid, and sensitive method was developed for As3+ in plasma using electrospray ionization (ESI) tandem mass spectrometry (MS-MS). After washing plasma with trichloroethylene (TCE), As3+ in the aqueous layer was reacted with pyrrolidinedithiocarbamate (PDC, C4H8NCSS-), and the produced As(PDC)3 was extracted with methyl isobutyl ketone (MIBK); a 1-µl aliquot of the MIBK layer containing As(PDC)3 was introduced into the MS-MS instrument in the direct-flow injection mode. Other arsenic compounds such as As5+, monomethyl arsonic acid, dimethyl arsinic acid, arsenobetaine, arsenocholine, and tetramethyl arsonium did not produce As(PDC)3. Therefore, without liquid chromatographic separation, As3+ alone could be detected after washing with TCE followed by solvent extraction of As(PDC)3 with MIBK. Thus, inorganic As5+ was reduced to As3+ with thiosulfate, and then the total inorganic As was quantifi ed as As3+; As5+could be calculated by subtracting As3+from the total inorganic As. The MS-MS quantification was performed by selected reaction monitoring using a peak at m/z 114 of a product ion (C4H8NCS)+ formed by collision-induced dissociation from the precursor ion As(PDC)2 at m/z 367. The mass spectral identification on MS-MS spectrum was possible even at 1 ng As+ at m/z 367. The mass spectral identification on MS-MS spectrum was possible even at 1 ng As3+ showed linearity from 0.5 to 100 ng/ml plasma. The limits of detection by selected reaction monitoring were 0.3 ng/ml in water and 0.2 ng/ml in plasma. The analysis could be completed in less than 15 min, because chromatographic separation was not necessary before the MS-MS detection. [ABSTRACT FROM AUTHOR]3+ showed linearity from 0.5 to 100 ng/ml plasma. The limits of detection by selected reaction monitoring were 0.3 ng/ml in water and 0.2 ng/ml in plasma. The analysis could be completed in less than 15 min, because chromatographic separation was not necessary before the MS-MS detection. [ABSTRACT FROM AUTHOR]

The Michaelis-Arbuzov reaction of ethyl α -bromo-α -fluoro- and α, α -difluoro-acetates with dialkyl phenylphosphonites leads to the formation of unusual products including a fluorophosphinate. The reaction of ethyl bromofluoracetate with diisopropyl- and dimethyl-phenylphosphonites furnishes a complex mixture of eight and five compounds respectively. Five different compounds are obtained when ethyl bromodifluoroacetate is reacted with diisopropyl phenylphosphonite. Dimethyl phenylphosphonite yields three compounds when heated with bromochloromethane. The probable mechanism of formation of the compounds and their mass spectral characterization using GC-MS, tandem MS-MS and DART™ techniques are presented in this paper. [ABSTRACT FROM AUTHOR]

A simple, rapid and sensitive method using tandem mass spectrometry (MS-MS) has been developed for the determination of chromate Cr6+ in urine. Cr6+ is a substantial component of Urine Luck, which is used to conceal the presence of drugs in urine. Cr6+ was complexed with diethyldithiocarbamate (DDC) and extracted with isoamyl alcohol in the presence of citric acid. Then a 1-μl aliquot of isoamyl alcohol containing Cr-DDC complex was directly injected into an MS-MS instrument without chromatographic separation. The quantification was performed using selected reaction monitoring at m/ z 363.8 of product ion CrO(DDC)2 + obtained by collision-induced dissociation from the precursor ion, CrOH(DDC)3 + at m/ z 513.1. This method was validated with the analysis urine samples obtained from volunteers. A linear calibration curve could be obtained in the range of 0.18–100 ng/ml. The limits of detection and quantification of Cr6+, near 100% recovery was confirmed using standard reference materials such as SRM 2670a (low level and high level) and SRM 1643e. The most outstanding advantage of this ESI-MS-MS method is that it gives excellent product ion mass spectra for identification of Cr3+ to Cr6+, near 100% recovery was confirmed using standard reference materials such as SRM 2670a (low level and high level) and SRM 1643e. The most outstanding advantage of this ESI-MS-MS method is that it gives excellent product ion mass spectra for identification of Cr6+. [ABSTRACT FROM AUTHOR]

A simple, rapid, and sensitive method has been developed for determination of platinum (Pt) in blood and urine by tandem mass spectrometry (MS-MS). Pt4+ in wet-ashed blood or acid-treated urine was complexed with diethyldithiocarbamate (DDC), extracted with isoamyl alcohol, and acidified with oxalic acid; a 1-μl aliquot of the isoamyl alcohol layer containing the Pt-DDC complex was directly injected into the MS-MS instrument without chromatographic separation. The quantitation was performed using selected reaction monitoring at m/z 491 of the product ion Pt(DDC), which was produced by collision-induced dissociation from the precursor ion Pt(DDC) at m/z 639. This method was validated for the analysis of blood and urine samples; the limits of quantitation were about 0.3 and 0.1 ng/ml for blood and urine, respectively, using only 10 μl of sample. The calibration curves for Pt in urine and blood showed linearity from 0.1 to 30 ng/ml. Because chromatographic separation is not required before MS-MS detection, the analysis can be completed in less than 10 min. [ABSTRACT FROM AUTHOR]

Abstract: The amino acid ornithine (Orn) acts as a vital part in the physiologically fundamental urea cycle. As such, it is a main intermediate in the catabolic breakdown as well as in the synthesis of arginine and is involved in many other metabolic pathways with potential clinical implications. We here describe a LC–MS-MS method for the detection of Orn in human plasma which is fast, easy and precise. The sample preparation comprises only protein precipitation and the addition of the isotopic labeled I.S. The analytes are separated by hydrophilic interaction chromatography (HILIC) in less than 4min on a silica column with an isocratic mobile phase consisting of 0.1% trifluoroacetic acid in water and acetonitrile in the ratio of 25:75. Orn and its I.S. are detected and quantified by APCI tandem mass spectrometry. The calibration function is linear from 7.5 to 205μmol/l and covers the range of concentrations found in patients undergoing different clinical interventions. The quantification results are independent with regard to the biological matrix analyzed. The intra-day and inter-day relative standard deviations are 1.1% and 3.5%, respectively. As an application of the described method in clinical investigations, we report arginine and ornithine plasma concentration results from an arginine supplementation study enrolling healthy volunteers and patients suffering from hypercholesterolemia. After oral dosing of 110mg/kg arginine, ornithine plasma concentrations rose from 54 to 148μmol/l after 2h and were back to baseline after 24h. However, arginine to ornithine ratios kept constant during the complete observation time. [Copyright &y& Elsevier]

Abstract: Background: An accurate measurement of testosterone is needed in many clinical applications for correct diagnosis and appropriate treatment. Our aim was to develop a fast and robust high-throughput LC-MSMS method for quantification of serum testosterone in women. Methods: Testosterone was derivatized by oximation and extracted with methyl tert-butyl ether from 200 μL of serum. Further matrix elimination was achieved on-line using a column-switching LC-method. The instrumental analysis was performed on an API4000 tandem mass spectrometer equipped with an Agilent series 1312A binary pump and an Agilent series 1311A quaternary pump. The MRM transitions were 304→124 and 304→112 for testosterone and 307→124 and 307→112 for d 3-testosterone. Results: The total analysis time of the column-switching method was 3 min. Linear calibration curves were obtained in the concentration range from 0.035 nmol/L (0.01 μg/L) to 6.92 nmol/L (2 μg/L). Within-day and between-day precision, expressed as the relative standard deviation at four different concentrations ranged from 4.70% to 9.35%. Correlation with the in-house method (solvent–extraction RIA) showed r 2 =0.920. Conclusions: The presented column-switching method offers a simple, fast and economical analysis of testosterone in human serum. The procedure requires only small sample volumes and is well suited for quantification of testosterone in serum from women and children. [Copyright &y& Elsevier]

Previous HPLC determination of atenolol on reversed-phase packings has often required a mobile phase containing three components: organic modifier, buffer and ion-pairing reagent or organic amine. In addition to the complexity of the eluents employed, alkyl sulphonates and organic amines in the mobile phase can reduce the life of silica-based bonded columns. A new simple, rapid and sensitive method—pseudo reversed-phase liquid chromatography/tandem mass spectrometry has been developed for the analysis of atenolol in human plasma using bare silica as the stationary phase coupled with a simple mobile phase consisted of 5% acetonitrile and 95% formate buffer. The optimization of separation is fast and easy. The assay was validated for the concentration range 1–100 ng mL−1 with a detection limit of 1 ng mL−1. Moreover, the silica column was durable with the mainly aqueous eluents. No obvious loss in performance was observed for 30,000 column volumes of eluent. [ABSTRACT FROM AUTHOR]

The article discusses the results of a study measuring the excretion of anthocyanins in human urine after ingestion of cranberry juice. An abundance of peonidin 3-0-galactoside, the second most plentiful anthocyanin in the cranberry juice, was found most abundantly in human urine within 24 hours. The urinary levels of anthocyanins reached a maximum between 3 and 6 hours after ingestion. Evidence shows that cranberry anthocyanins are highly absorbed and excreted in human urine.

Abstract: A sensitive, specific and reproducible method for the quantitative determination of the anabolic metandienone in human hair has been developed. The preparation involved a decontamination step with methylene chloride. The hair sample (about 50mg) was solubilised in 1ml 1M NaOH, 10min at 95°C, in presence of 2ng of nandrolone-d 3 used as internal standard. The homogenate was neutralized and extracted using consecutively a solid-phase extraction (Isolute C18 eluted with methanol) and a liquid–liquid extraction with pentane. The residue was derivatized by adding 5μl MSTFA/NH4I/2-mercaptoethanol (250μl; 5mg; 15μl) and 45μl MSTFA, then incubated for 20min at 60°C. A 1μl aliquot of derivatized extract was injected into the column (HP5-MS capillary column, 5% phenyl–95% methylsiloxane, 30m×0.32mm i.d., 0.25μm film thickness) of a Hewlett Packard (Palo Alto, CA, USA) gas chromatograph (6890 Series). Metandienone was identified using three transitions (its daughter ions at m/z 339 and 206 for the parent 444 and 191 for 206) using a Waters Quattro Micro MS–MS system. The transition m/z 444 to 206 has been used as quantification transition and the others as identification transitions. The assay was capable of detecting 2pg/mg of metandienone when approximately 50mg of hair material was processed. Linearity was observed for metandienone concentrations ranging from 2 to 500pg/mg with a correlation coefficient of 0.9997. Intra-day and between-day precisions at 50pg/mg were 13.4–16.5% and 22.0%, respectively, with an extraction recovery of 48%. The analysis of hair, cut into four segments, obtained from an athlete, revealed the presence of metandienone at the concentrations of 78, 7, 10 and 108pg/mg in each segment of hair (0–1, 1–2, 2–3 and 3cm to the tip). [Copyright &y& Elsevier]

Abstract: A multi-residue method has been developed for determining 65 pesticide residues in greasy vegetable matrices such as avocado. Conventional organic solvent extraction assisted by a high-speed homogenizer was compared to pressurized liquid extraction (PLE) as extraction techniques. Following this, the lipophilic extract was purified using gel permeation chromatography (GPC). Alternative clean-up methods were also evaluated, as solid-phase extraction cartridges individually used and downstream coupled, but less effective lipophilic separation was archived. The pesticide residue determination was carried out using low-pressure gas chromatography coupled to tandem mass spectrometry (LP-GC–MS–MS), showing the applicability of this type of GC columns for the analysis of fat vegetable matrices. The proposed methodology was validated in avocado matrix. The recoveries were in the range 70–110%, with RSD values lower than 19%, at 12 and 50μg/kg spiking levels. The limits of quantitation (LOQs) were in the range 0.04–8.33μg/kg and the limits of detection (LODs) were between 0.01 and 2.50μg/kg. All of them were lower than the maximum residue levels (MRLs) set by the European Union (EU) in avocado. The proposed method was evaluated analyzing pesticide residues in real avocado samples. [Copyright &y& Elsevier]

Abstract: We have combined the benefits of supersonic molecular beam interface and its related fly-through electron ionization (EI) ion source with the advanced features of the Varian 1200L gas chromatography–mass spectrometry (GC–MS) and mass spectrometry–mass spectrometry (MS–MS), resulting in a new and powerful GC–MS platform with record setting performance. Electron ionization of vibrationally cold molecules in the supersonic molecular beams (SMB) (cold EI) provided mass spectra with enhanced molecular ion, yet with good library search results and superior identification probabilities. We found that high GC column flow rates lower the elution temperature for any given compounds. This allows much larger molecules to elute at the maximum temperature of standard columns. We analyzed a mixture of heavy linear chain hydrocarbons all the way to C84H170 with a molecular weight of 1179.3amu, using a 4m 0.25mm i.d. column and 32ml/min He flow rate. Furthermore, we obtained a dominant molecular ion to all these compounds. The lower elution temperatures also greatly enhance the ability to analyze very thermally labile compounds such as carbamate pesticides. The experimental 1200 system is capable of triple quadrupole based MS–MS. We found that MS–MS on the molecular ion is much more effective than on fragment ions, and thus, the enhancement of the molecular ion directly improves the MS–MS sensitivity. Fast GC–MS analysis was also explored, based on very high column flow rate for fast splitless injections without affecting the sensitivity, and on the high system selectivity due to the combination of enhanced molecular ion and MS–MS. We demonstrate a few seconds long GC–MS–MS analysis of diazinon, spiked at 10ng/g in a mixed fruit and vegetable extract. The feature of enhanced molecular ion provides significant enhancement in the detection sensitivity via SIM and RSIM on the molecular ion. While octafluoronaphthalene (OFN) detection limit of below 1fg in SIM mode is shown, the harder is the compound analysis by standard GC–MS the greater is the gain in sensitivity by 1200-SMB. For example, the use of the 1200-SMB resulted in an improvement of over 50 times in the RSIM detection limit of cholesterol on its molecular ion at m/z =386, and decabromobiphenylether could be analyzed in SIM mode at 1ppb with S/N>50 (peak-to-peak noise). [Copyright &y& Elsevier]

Abstract: Atmospheric pressure chemical ionisation (APCI) sources were developed for real time analysis of volatile release from foods using an ion trap (IT) mass spectrometer (MS). Key objectives were spectral simplicity (minimal fragmentation), response time and signal to noise ratio. The benefits of APCI-IT-MS were assessed by comparing the performance for in vivo and headspace analyses with that obtained using APCI coupled to a quadrupole mass analyser. Using MS–MS, direct APCI-IT-MS was able to differentiate mixtures of some C6 and terpene isobaric aroma compounds. Resolution could be achieved for some compounds by monitoring specific secondary ions. Direct resolution was also achieved with two of the three isobaric compounds released from chocolate with time as the sample was eaten. [Copyright &y& Elsevier]

Abstract: Investigations have been made to develop an efficient protocol for micropropagation allowing to improve hypericin and pseudohypericin productions in Hypericum perforatum L. in vitro cultures. The role of growth regulator treatments has been particularly studied. Three in vitro culture lines with different morphological characteristics were obtained during H. perforatum micropropagation and referred to shoots, calli and plantlets according to their appearance. Multiplication and callogenesis from apical segments from sterile germinated seedlings were obtained on solid MS/B5 culture medium in the presence of N6-benzyladenine (BA) (0.1–5.0 mg/l BA). Regenerative potential of shoots was assessed on medium supplemented with auxins (0.05–1.0 mg/l), indole-3-acetic acid (IAA) or indole-3-butyric acid (IBA). The main goal of the research was to summarize the influence of plant growth regulators on hypericin and pseudohypericin productions in in vitro cultures of Hypericum. A rapid method for naphtodianthrone quantification was developed. The use of a reversed-phase high performance liquid chromatography (HPLC) method with fluorescence detection was used. Identification of the compounds was confirmed by electrospray ionization-mass spectrometry (ESI-MS) with electrospray in negative ion mode [M–H]¯. Calli, shoots and plantlets of H. perforatum produced hypericin and pseudohypericin. The concentration range of BA from 0.1 to 2.0 mg/l improved the production of hypericin (25–50 μg/g dry mass (DM)) and pseudohypericin (170–350 μg/g DM) in shoots. In callus cultures, BA (4.0–5.0 mg/l) did not changed hypericin contents (15–20 μg/g DM) but influenced pseudohypericin productions (120–180 μg/g DM). In the presence of auxins (IAA and IBA), Hypericum plantlets produced hypericin (30–100 μg/g DM) and pseudohypericin (120–400 μg/g DM). The presence of IAA did not influence naphtodianthrone productions in plantlets, but IBA decreased hypericin and pseudohypericin amounts in plantlets. The specific accumulation of the naphtodianthrones in in vitro cultures was influenced by phytohormonal supplementation of the medium. Results indicated that the production of hypericin and pseudohypericin could be increased by carefully adapted in vitro cultures. Hypericum in vitro cultures represent promising systems for hypericin and pseudohypericin productions. [Copyright &y& Elsevier]

Abstract: Three pairs of ginsenoside isomers (Rg2 and Rg3, Rg1 and F11 as well as Rd and Re) were differentiated and identified through accurate mass measurement of mass spectrometry (MS) and MS–MS. [M+Li]+ and [M-H]- ions were detected in full-scan MS analyses and selected for the MS–MS experiments using positive and negative ion electrospray ionizations (ESI), respectively. The structures of aglycone and α- and β-saccharide sugars in various ginsenosides were determined from the spectrum interpretation and accurate mass measurement. Z and C type ions were predominantly observed in the MS–MS spectra of [M+Li]+ ions, while Y type ions were the most abundant ions in the spectra obtained from the negative ion mode analysis. Furthermore, X and A ions resulted from cross-ring cleavage on the sugar directly connected to aglycone were detected in both positive and negative ion spectra, which provided the site information of the saccharide chains. The obtained MS–MS profiles were used for the structural confirmation of ginsenoside Rg2 collected from column chromatography separation of a Chinese Panax ginseng extract. The ESI–MS data with accurate mass assignment suggested that a co-eluted ginsenoside also existed in the sample fraction. The interpretation of its MS–MS spectrum and fragmentation pathways allowed the detection of the ginsenoside Rf, differentiating from its isomers Rg1 and F11. [Copyright &y& Elsevier]

Brominated flame retardants (BFRs) comprise diverse chemical compounds used in a variety of commercial applications. Those used most are polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA). The impact of BFRs on the environment and their potential risks for animals and humans is of concern to the scientific community. A number of studies have reported analytical methods and levels of some BFRs, especially PBDEs, in sediments and biota. However, there is much less literature relating to sewage sludge and treated soil. In this article, we discuss the use of different sample-preparation techniques applied to these matrices, as well as the different approaches to mass spectrometry (MS). Finally, we review the available data concerning the occurrence of BFRs in sewage sludges, before presenting our conclusions and outlining future perspectives. [Copyright &y& Elsevier]

A rapid static headspace-gas chromatography–mass spectrometry (GC–MS) method was used to determine and to identify the volatile compounds in the rhizomes of Rhodiola sachalinensis and Rhodiola sacra. The total ion chromatograms (TIC) of the rhizomes powders of the R. sachalinensis and R. sacra showed their differences in the volatiles compositions. Thirty two volatile compounds in the rhizome of R. sachalinensis were identified; the main volatile compounds are butanal, 2,6,6-trimethyl-2-ethenyltetrahydro-2-pyran, limonene, linalool, geranial, 2-butanal, and 3-butanal. Twenty five volatile compounds in the rhizome of R. sacra were identified with butanal, 3-butanal, 2-butanal, β-pinene, limonene, terpinolene, and linalool. 2,6,6-Trimethyl-2-ethenyltetrahydro-2-pyran was further identified by the MS–MS technique. The applied method not only effectively differentiates the two species of Rhodiolas but also offers a prospective method for the quality control of aromatic medicine plants. [ABSTRACT FROM AUTHOR]

A study of processed peanut oil was undertaken to assess the utility of HPLC combined with tandem MS to obtain data easily regarding the number of TAG of fats and oils and their FA composition. Mass chromatograms and spectra corresponding to only TAG of a single M.W. were obtained for the full range of TAG in the sample. Analysis of the mass spectra allowed the identification of more than 160 TAG in the sample by their FA composition. In addition, it was possible to estimate relative abundances of the TAG and suggest the position of the FA on glycerol for a limited number of cases. This technique greatly simplifies the task of assigning FA to coeluting TAG and facilitates identification of TAG present in trace quantities in mixtures, with possible application in circumstances where such trace TAG could be significant markers. Results are quickly obtained without extensive sample preparation or prefractionation of the sample. [ABSTRACT FROM AUTHOR]

Plant allelopathy offers hope as an additional means of weed control in modern agriculture. Its mechanisms and molecular basis are not yet well understood. Research on the chemical basis for allelopathy has often been hindered by the complexity of plant and soil matrices, making it difficult to track active compounds. Recent improvements in the cost and capabilities of bench-top chromatography–mass spectrometry instruments make these tools more powerful and more widely available to assist with molecular studies conducted in today's expanding field. Such instrumental techniques are herein recommended as economically efficient means of advancing the rigor of allelopathy research and assisting the development of a better understanding of the chemical basis for the allelopathy phenomenon. [ABSTRACT FROM AUTHOR]

Cruciata articulata (L.) Ehrend. is a herbaceous species distributed in parts of Western Asia and the Mediterranean region. While research on other species in the Cruciata genus has revealed the presence of a range of flavonoids and terpenoids, few such studies have been conducted on C. articulata. Thus, in the current study, a phytochemical investigation of C. articulata was carried out. Molecular networking identified a large cluster of compounds sharing distinctive MS-MS fragmentation patterns that were targeted for isolation, leading to the isolation of five undescribed monoterpenoid glycosides, cruciasides C-G, along with two known monoterpenoid glycosides. The structures of these compounds were elucidated by using chemical and spectroscopic analyses, including 1D and 2D NMR, and MS-MS fragmentation. Structures for the ions observed in the MS-MS were proposed, and based on these fragmentation patterns, structures for several of the minor components observed in the molecular network were also proposed. All isolated compounds were tested for cytotoxic, anti-inflammatory, antimicrobial, and α-glucosidase inhibitory properties, but did not display any activity. [Display omitted] • Chemical investigation of C. articulata gave five previously undescribed aromatic terpene glycosides. • First report of terpene glycosides from Cruciata articulata. • Analysis of MS-MS fragmentation enabled tentative identification of minor components. [ABSTRACT FROM AUTHOR]

[Display omitted] • Directed biosynthesis with B. subtilis forms polyfluorinated surfactins. • MS-MS shows preferential inclusion of trifluoroleucine at Leu1 and Leu2 positions. • Trifluoroleucine also undergoes deamination and reduction. Supplementation of the culture medium of a Bacillus subtilis strain with 5,5,5-trifluoroleucine resulted in the production of modified surfactins. Products were characterized by 19F NMR and LC–MS/MS, confirming fluorinated leucine could be incorporated in place of any of the four leucine residues present in native surfactins, with the Leu1 and Leu2 positions incorporating a higher percentage of the modified amino acids. However, analysis of the culture supernatant showed that a significant amount (0.5 mg/mL) trifluoroleucine was not metabolized and retained in the supernatant and methanolic extract; further, MS and HPLC analysis indicated that some of the trifluoroleucine had also undergone deamination and reduction reactions to yield 5,5,5-trifluoro-2-hydroxy-4-methylpentanoic acid as the major product (0.25 mg/1.0 mg trifluoroleucine). [ABSTRACT FROM AUTHOR]

A phytochemical investigation of the roots of Xerophyllum tenax led to the isolation of three undescribed feruloyl sucrose derivatives along with two known feruloyl sucrose derivatives, heloniosides A and B. This is the first report of their occurrence in the genus Xerophyllum and the family Melanthiaceae. The structures of these compounds were elucidated on the basis of chemical and spectroscopic analysis including 1D and 2D NMR and analysis of MS-MS fragmentation. Chemical investigation of Xerophyllum tenax yielded five feruloyl sucrose derivatives, including three undescribed compounds containing both E - and Z -feruloyl groups. [Display omitted] • Chemical investigation of Xerophyllum tenax yielded feruloyl sucrose derivatives. • First report of this compound class in the family Melanthiaceae. • Analysis of MS-MS fragments identified characteristic fragmentation patterns. [ABSTRACT FROM AUTHOR]