Surface-assisted Laser Desorption/ionization Mass Spectrometry Analysis of the Glycolipid Biosurfactants, Mannosylerythritol Lipids, Using an Ionization-assisting Substrate.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a promising tool for the screening of glycolipid-type biosurfactants (BSs) from a crude extract of microbial products. However, it is unsuitable for the detection of lower molecular weight products because the observed ions are overlapped with matrix-derived ions at lower mass range. In this study, we applied a "matrix-free" surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) analysis using a through-hole alumina membrane as an ionization-assisting substrate. Using this method, we could detect a variety of lower molecular weight products in an extract of a glycolipid BS producer with good sensitivity. In addition, the culture solution could be analyzed directly by this method.

Improved Protein and PTM Characterization with a Practical Electron-Based Fragmentation on Q-TOF Instruments.

Electron-based dissociation (ExD) produces uncluttered mass spectra of intact proteins while preserving labile post-translational modifications. However, technical challenges have limited this option to only a few high-end mass spectrometers. We have developed an efficient ExD cell that can be retrofitted in less than an hour into current LC/Q-TOF instruments. Supporting software has been developed to acquire, process, and annotate peptide and protein ExD fragmentation spectra. In addition to producing complementary fragmentation, ExD spectra enable many isobaric leucine/isoleucine and isoaspartate/aspartate pairs to be distinguished by side-chain fragmentation. The ExD cell preserves phosphorylation and glycosylation modifications. It also fragments longer peptides more efficiently to reveal signaling cross-talk between multiple post-translational modifications on the same protein chain and cleaves disulfide bonds in cystine knotted proteins and intact antibodies. The ability of the ExD cell to combine collisional activation with electron fragmentation enables more complete sequence coverage by disrupting intramolecular electrostatic interactions that can hold fragments of large peptides and proteins together. These enhanced capabilities made possible by the ExD cell expand the size of peptides and proteins that can be analyzed as well as the analytical certainty of characterizing their post-translational modifications.

Localization of Major Ephedra Alkaloids in Whole Aerial Parts of Ephedrae Herba Using Direct Analysis in Real Time-Time of Flight-Mass Spectrometry.

Mass spectrometry-based molecular imaging has been utilized to map the spatial distribution of target metabolites in various matrixes. Among the diverse mass spectrometry techniques, matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) is the most popular for molecular imaging due to its powerful spatial resolution. This unparalleled high resolution, however, can paradoxically act as a bottleneck when the bio-imaging of large areas, such as a whole plant, is required. To address this issue and provide a more versatile tool for large scale bio-imaging, direct analysis in real-time-time of flight-mass spectrometry (DART-TOF-MS), an ambient ionization MS, was applied to whole plant bio-imaging of a medicinal plant, Ephedrae Herba. The whole aerial part of the plant was cut into 10-20 cm long pieces, and each part was further cut longitudinally to compare the contents of major ephedra alkaloids between the outer surface and inner part of the stem. Using optimized DART-TOF-MS conditions, molecular imaging of major ephedra alkaloids of the whole aerial part of a single plant was successfully achieved. The concentration of alkaloids analyzed in this study was found to be higher on the inner section than the outer surface of stems. Moreover, side branches, which are used in traditional medicine, represented a far higher concentration of alkaloids than the main stem. In terms of the spatial metabolic distribution, the contents of alkaloids gradually decreased towards the end of branch tips. In this study, a fast and simple macro-scale MS imaging of the whole plant was successfully developed using DART-TOF-MS. This application on the localization of secondary metabolites in whole plants can provide an area of new research using ambient ionization mass spectroscopy and an unprecedented macro-scale view of the biosynthesis and distribution of active components in medicinal plants.

Intact Protein Mass Spectrometry for Therapeutic Protein Quantitation, Pharmacokinetics, and Biotransformation in Preclinical and Clinical Studies: An Industry Perspective.

Recent advancements in immunocapture methods and mass spectrometer technology have enabled intact protein mass spectrometry to be applied for the characterization of antibodies and other large biotherapeutics from in-life studies. Protein molecules have not been traditionally studied by intact mass or screened for catabolites in the same manner as small molecules, but the landscape has changed. Researchers have presented methods that can be applied to the drug discovery and development stages, and others are exploring the possibilities of the new approaches. However, a wide variety of options for assay development exists without clear recommendation on best practice, and data processing workflows may have limitations depending on the vendor. In this perspective, we share experiences and recommendations for current and future application of mass spectrometry for biotherapeutic molecule monitoring from preclinical and clinical studies.

Development of a new atmospheric pressure plasmaspray ionization for ambient mass spectrometry.

A new atmospheric pressure ionization method, plasmaspray ionization, termed as PSI, was developed to be an alternative ambient ion source for mass spectrometry. It comprises a plasma jet device and a sample spray part. While the nonthermal plasma jet strikes the surface of stainless steel tube out of the spray capillary, the sprayed sample will be ionized with the assistant of auxiliary gas. Although PSI is a little bit more complex than electrospray ionization (ESI) in instrument, it shows both better linearity and higher sensitivity for organic compounds. For protein samples, it presents wider distributions of multiply charged ions and higher mass resolution without sacrificing any sensitivity. For the mechanism of PSI, the charge build-up process on the tip of capillary should play a key role for the ion formation, and the stimulated pulsed voltage on the flow tube will promote the ion aggregation speed until the charge density is high enough. PSI source contains the features of plasma ionization and ESI and can be considered as a novel combo bridging these techniques. These results reflect that this method of PSI can be applied and further developed as a versatile new ion source for a wild range of organic and biological samples.

Low-Pressure Photoionization in a Dual-Ion Funnel Injector Coupled to an Orbitrap Mass Spectrometer for Direct Analysis of Human Breath and Head-Space Sampled Coffee Roasts.

Low-pressure photoionization (LPPI) is a versatile tool for the mass spectrometric detection of (semi-)volatile organic compounds, (s)VOC. Here, a dual-ion funnel MALDI/ESI ion injector was equipped with a direct-inlet LPPI module. A radio-frequency (RF) drive enabled the implementation of three Kr discharge lamps in a novel design optimized for efficient photoionization and undisturbed ion trajectories. Supported by expansion and collisional cooling and, optionally, dopant vapor, primarily intact radical ions and protonated molecules were generated. Molecular identification was supported by the high-resolving power of an Orbitrap mass analyzer. In our proof-of-concept study, exhaled human breath and head-space sampled coffee grounds were characterized with this high-throughput technique. From breath, a few hundred and for the coffee roasts more than thousand distinct (s)VOC features were recorded. Principal component analysis enabled the differentiation of coffee grounds by origin and roasting protocol.

Comprehensive online multicolumn two-dimensional liquid chromatography-diode array detection-mass spectrometry workflow as a framework for chromatographic screening and analysis of new drug substances.

The analysis of complex mixtures of closely related species is quickly becoming a bottleneck in the development of new drug substances, reflecting the ever-increasing complexity of both fundamental biology and the therapeutics used to treat disease. Two-dimensional liquid chromatography (2D-LC) is emerging as a powerful tool to achieve substantial improvements in peak capacity and selectivity. However, 2D-LC suffers from several limitations, including the lack of automated multicolumn setups capable of combining multiple columns in both dimensions. Herein, we report an investigation into the development and implementation of a customized online comprehensive multicolumn 2D-LC-DAD-MS setup for screening and method development purposes, as well as analysis of multicomponent biopharmaceutical mixtures. In this study, excellent chromatographic performance in terms of selectivity, peak shape, and reproducibility were achieved by combining reversed-phase (RP), strong cation exchange (SCX), strong anion exchange (SAX), and size exclusion chromatography (SEC) using sub-2-µm columns in the first dimension in conjunction with several 3.0 mm × 50 mm RP columns packed with sub-3-µm fully porous particles in the second dimension. Multiple combinations of separation modes coupled to UV and MS detection are applied to the LC × LC analysis of a protein standard mixture, intended to be representative of protein drug substances. The results reported in this study demonstrate that our automated online multicolumn 2D-LC-DAD-MS workflow can be a powerful tool for comprehensive chromatographic column screening that enables the semi-automated development of 2D-LC methods, offering the ability to streamline full visualization of sample composition for an unknown complex mixture while maximizing chromatographic orthogonality. Graphical Abstract.

Rapid analysis of nine lignans in Schisandra chinensis by supercritical fluid chromatography using diode array and mass spectrometric detection.

Lignans are the bioactive constituents in Schisandra chinensis fruits. For the first time major representatives could directly be determined in plant extracts by using Supercritical Fluid Chromatography. Based on nine commercially available standards the method was developed, finally permitting their baseline separation in less than 10 min. The optimum setup showed to be a Viridis HSS C18 SB column, supercritical carbon dioxide and methanol. The compounds could be assigned in the extracts either at 210 nm or by MS, for which no modifications except of an additional sheath liquid (0.1 % acetic acid in methanol) were required. The determined lignan patterns were typical for S. chinensis, with schisandrol A being the most abundant compound, followed by schisandrin B or schisandrol B. As method validation results also complied well with the requirements the here presented method is definitely an interesting alternative to established techniques like UHPLC for the analysis of lignans in Schisandra chinensis.

Novel experimental approach to study aroma release upon reconstitution of instant coffee products.

This study presents an experimental approach to study the kinetics and fast release of volatile organic compounds (VOCs) upon reconstitution of instant coffee products. A sampling setup coupled to PTR-ToF-MS (Proton Transfer Reaction Time-of-Flight Mass Spectrometry) for the automated and reproducible reconstitution of instant coffee products was developed to monitor the dynamic release of VOCs. A rapid release of aroma compounds was observed in the first seconds upon hot water addition ("aroma burst"), followed by subsequent decrease in headspace (HS) intensities over the course of analysis. Differences in time-intensity release profiles of individual VOCs were correlated to their Henry's Law constant, vapor pressure and water solubility. The setup and approach proposed here have shown to be sensitive and to respond to fast dynamic changes in aroma release. It allows studying VOCs release upon reconstitution and supports the development of novel technologies and formulations for instant products with improved aroma release properties.

Laser Capture Microdissection-Liquid Vortex Capture Mass Spectrometry Metabolic Profiling of Single Onion Epidermis and Microalgae Cells.

Laser capture microdissection is a valuable technique in individually isolating single cells whether in tissue networks or deposited from a cell suspension. New developments have enabled coupling of laser capture microdissection with mass spectrometry via liquid vortex capture sampling probe. This enables online metabolic profiling of sectioned cells. Here, we describe the protocol used to deposit, isolate, and individually chemically characterize single Allium cepa and Chlamydomonas reinhardtii cells by laser capture microdissection-liquid vortex capture mass spectrometry.

Integration of micro-fractionation, high-performance liquid chromatography-ultraviolet detector-charged aerosol detector-mass spectrometry analysis and cellular dynamic mass redistribution assay to accelerate alkaloid drug discovery.

Natural products, including alkaloids, are important resources for new drugs. However, in today's high throughput screening (HTS) environment, natural product drug discovery programs are challenged for their low efficiency. In order to adapt to current HTS models, we here developed a rapid, sample-saving and miniaturized paradigm that seamlessly integrated alkaloid micro-fractionation, quantitative analysis, qualitative analysis and phenotypic screening. In the work, alkaloid samples were analyzed and fractionated on an analytical charged C18 column (150 × 4.6 mm, i.d.), and fraction qualities were determined by a charged aerosol detector (CAD). Fraction activities on dopamine D2 receptor were screened by cellular dynamic mass redistribution (DMR) assay and active fractions were further characterized by high-resolution mass spectrometry (MS). The whole workflow was first validated by mixed standard for accuracy, and then by 300 µg of Corydalis yanhusuo extract for its feasibility in complex samples. Finally, the method was applied for sample prioritization in four papaveraceae family plants and 21 compounds were predicted to be active, and Corydalis yanhusuo and Corydalis decumbens were determined as promising species for activity tracking. Overall, these results highlighted the feasibility of this miniatured and integrated model in rapid alkaloid screening. Advantages of this workflow were: first, the highly efficient separation method accelerated alkaloid fractionation; second, the analytical and biological test were conducted on the same scale; third, the quantification method ensured accurate screening on microscale; last, the combination of MS analysis and data mining strategy accelerated the decision-making process in the primary screening.

Multineuromodulator measurements across fronto-striatal network areas of the behaving macaque using solid-phase microextraction.

Different neuromodulators rarely act independent from each other to modify neural processes but are instead coreleased, gated, or modulated. To understand this interdependence of neuromodulators and their collective influence on local circuits during different brain states, it is necessary to reliably extract local concentrations of multiple neuromodulators in vivo. Here we describe results using solid-phase microextraction (SPME), a method providing sensitive, multineuromodulator measurements. SPME is a sampling method that is coupled with mass spectrometry to quantify collected analytes. Reliable measurements of glutamate, dopamine, acetylcholine, and choline were made simultaneously within frontal cortex and striatum of two macaque monkeys (Macaca mulatta) during goal-directed behavior. We find glutamate concentrations several orders of magnitude higher than acetylcholine and dopamine in all brain regions. Dopamine was reliably detected in the striatum at tenfold higher concentrations than acetylcholine. Acetylcholine and choline concentrations were detected with high consistency across brain areas within monkeys and between monkeys. These findings illustrate that SPME microprobes provide a versatile novel tool to characterize multiple neuromodulators across different brain areas in vivo to understand the interdependence and covariation of neuromodulators during goal-directed behavior. Such data would be important to better distinguish between different behavioral states and characterize dysfunctional brain states that may be evident in psychiatric disorders.NEW & NOTEWORTHY Our paper reports a reliable and sensitive novel method for measuring the absolute concentrations of glutamate, acetylcholine, choline, dopamine, and serotonin in brain circuits in vivo. We show that this method reliably samples multiple neurochemicals in three brain areas simultaneously while nonhuman primates are engaged in goal-directed behavior. We further describe how the methodology we describe here may be used by electrophysiologists as a low-barrier-to-entry tool for measuring multiple neurochemicals.

Antidiabetic Potential of Mangifera indica L. cv. Anwar Ratol Leaves: Medicinal Application of Food Wastes.

Background and objectives: Anwar Ratol is one of the most famous cultivar of mango in South Asia, especially Pakistan. Mango leaves are left as food waste. This study evaluated the potential of mango (Anwar Ratol) leaves for their use against diabetes mellitus. Material and Methods: In this study, hydro-alcoholic extract of the plant leaves was prepared and evaluated by electrospray ionization mass spectroscopy (ESI-MS) and high-performance liquid chromatography (HPLC) for the presence of phytochemicals. The plant extract was administered to Alloxan induced diabetic mice followed by evaluation through oral glucose tolerance test; determination of postprandial glucose, body weight, lipid profile and histopathological evaluation of pancreas. Results: Chemical evaluation revealed the presence of mangiferin, rhamnetin, catechin, epicatechin, iriflophenone 3-C-ß-D-glucoside, gallic acid and other phenolic and flavonoid compounds. The plant extract exhibited a decrease in postprandial blood glucose following seven days therapy in diabetic mice. The extract also prevented the rise in blood glucose level as determined by glucose tolerance test in diabetic mice. Furthermore, therapy of diabetic mice with the extract prevented a decrease in body weight and decline in beta-cell mass associated with alloxan and improved lipid profile. Conclusion: The findings of the study clearly suggested that the leaf extract of the plant might possess anti-diabetic activity possibly due to the presence of mangiferin and other phytochemicals such as phenolic and flavonoid compounds. This study will serve as a basis for the use of mango leaf extract against diabetes. Furthermore, this study will also provide basis for the bioassay-based fractionation and isolation of active principles responsible for the antidiabetic potential of mango leaves.

Preparative HPLC Separation of Underivatized Amino Acids for Isotopic Analysis.

Single-compound analysis of stable or radioactive isotopes has found application in a number of fields ranging from archaeology to forensics. Often, the most difficult part of these analyses is the development of a method for isolating the compound(s) of interest, which can derive from a wide range of sample types including the hair, nails, and bone.Here we describe three complementary preparative HPLC techniques suitable for separating and isolating amino acids from bone collagen and hair keratin. Using preparative reversed-phase, ion-pair, or mixed-mode chromatography in aqueous carbon-free mobile phases, or those from which carbon can easily be removed, underivatized single amino acids can be isolated and further analyzed using mass spectrometric techniques.

Exploring the Application of the DSA-TOF, a Direct, High-resolution Time-of-Flight Mass Spectrometry Technique for the Screening of Potential Adulterated and Contaminated Herbal Medicines.

Global consumption of complementary and alternative medicines, including herbal medicines, has increased substantially, and recent reports of adulteration demonstrate the need for high throughput and extensive pharmacovigilance to ensure product safety and quality. Three different standard reference materials and five previously analyzed herbal medicines have been used as a proof of concept for the application of adulteration/contamination screening using a Direct Sample Analysis (DSA) ion source with TOF MS on the Perkin Elmer AxION 2 TOF. This technique offers the advantages of minimum sample preparation, rapid analysis, and mass accuracies of 5 ppm. The DSA TOF analysis correlates well with the previous analysis on the initial sample set (which found undeclared herbal ingredients), with the added advantage of detecting previously untargeted compounds, including species-specific flavonoids and alkaloids. The rapid analysis using the DSA-TOF facilitates screening for hundreds of compounds in minutes with minimal sample preparation, generating a comprehensive profile for each sample. Graphical Abstract.

Chemical comparison of Prunus africana bark and pygeum products marketed for prostate health.

The bark of Prunus africana may contain atranorin, atraric acid, beta-sitosterol and its esters, ferulic acid and its esters, and N-butylbenzene sulfonamide, compounds that have been shown to improve the conditions of benign prostatic hyperplasia, enlarged prostate. An analytical scheme, involving liquid-solid extractions, saponifications, and LC-APCI-MS (triple quadrupole) analysis, was developed, optimized, and validated to determine the compounds at µg/g levels. Limits of quantification were in the low ng/mL range except for beta-sitosterol. All of the compounds plus two internal standards eluted in under 10 min on a phenyl-hexyl column with gradient elution involving water-methanol and acetonitrile. The mass fraction of the compounds in Prunus africana bark (four samples) and commercial pygeum products (seven samples), derived from bark, were compared. Bark and pygeum were similar in their content of atranorin and atraric acid, found at low µg/g levels, and in the fact that ferulic acid was almost totally (> 90%) in the form of esters. In contrast, the total amount of ferulic acid was on average four times higher in bark (450 µg/g) than in pygeum while the opposite was true for total beta-sitosterol. Some pygeum samples had levels of total beta-sitosterol above 10,000 µg/g while the compound in bark was relatively invariant at about 680 µg/g. The fraction of free beta-sitosterol varied significantly between bark (33%) and pygeum (nearly all). In pygeum, the measured total beta-sitosterol concentration generally followed the labeled values for phytosterol content. No N-butylbenzene sulfonamide was found in any of the bark and pygeum samples.

Determinação de estimulantes, esteroides anabolizantes, diuréticos e laxante por HPLC-DAD e LC-MS/MS em suplementos alimentares adulterados disponíveis no Brasil / Determination of stimulants, anabolic steroids, diuretics and laxative by HPLC-DAD and LC-MS/MS in adulterated dietary supplements available in Brazil

A adulteração de suplementos alimentares pela adição de substâncias farmacologicamente ativas e um problema que vem se agravando nos últimos anos. Essas substâncias são adicionadas intencionalmente nos produtos, com objetivo de melhorar a sua eficácia, sem que essa adição seja devidamente informada nos rótulos. O consumo de suplementos adicionados de substâncias farmacologicamente ativas nao declaras nos rótulos e, alem de um problema de saúde pública, um risco a carreira de atletas profissionais, quando se trata de doping no esporte. Neste trabalho foram desenvolvidos métodos analíticos baseados em cromatografia líquida para detecção de 19 substâncias farmacologicamente ativas em amostras de suplementos alimentares, nos niveis de contaminação cruzada e adulteração. Para tal, empregou-se a cromatografia líquida de alta eficiência acoplada a detector de arranjo de diodos (HPLC-DAD) e a cromatografia líquida acoplada a espectrometria de massas sequencial (LC-MS/MS). As substâncias investigadas apresentam ação androgênica e anabólica (i.e. testosterona, metiltestostetona, propionato de testosterona, decanoato de testosterona, trembolona, estanozolol, dehidroepiandrosterona, androstenediona, decanoato de nandrolona, oxandrolona e metasterona), estimulante (i.e. cafeína), anorexigena (i.e. sibutramina), diurética (i.e. amilorida, bumetanida, furosemida, hidroclorotiazida e clortalidona) e laxante (i.e. fenolftaleina). Entre os métodos de preparo de amostra avaliados (Quechers e extração sólido-líquido seguida de uma etapa de precipitação de proteína), a extração sólido-líquido empregando metanol como solvente extrator e ZnSO4 como agente precipitante apresentou-recuperação acima de 80% para todas as substâncias avaliadas, sendo selecionado para o fim deste estudo. Os métodos analíticos propostos apresentaram limites de detecção e de quantificação na faixa de contaminação, foram seletivos e lineares com r2 superior a 0,99 na faixa de concentração de interesse para todas as substâncias e valores de recuperação, precisão e exatidão dentro dos valores aceitáveis. Um conjunto amostral representativo dos suplementos alimentares comercializados no Brasil, constituído por 230 amostras, foi analisado sendo que mais de 25% do conjunto amostra foram positivos para cafeína (48), sibutramina (14), fenolftaleína (2) e furosemida (3), isoladas ou associadas entre si. Os métodos desenvolvidos utilizaram um preparo de amostra simples e apresentaram resultados satisfatórios para a investigação de possível adulteração ou contaminação com 19 das substâncias de interesse. Dos 58 suplementos alimentares adulterados, apenas 11 podem ser considerados adulterados por contaminação cruzada. Os demais, são consideradas adições dolosas por parte dos fabricantes com objetivo de melhorar a eficiência dos seus produtos. Os resultados aqui apresentados indicam a necessidade de ações mais efetivas por parte das autoridades sanitárias no sentido de fiscalizar com mais eficiência a produção e a comercialização desses produtos e alertar a população para que fiquem atentos a possível adulteração de suplementos alimentares e aos riscos associados ao consumo desses produtos

The adulteration of dietary supplements by the addition of pharmacologically active substances is a serious issue, which is aggravating steadily. These substances are added intentionally in various products, with the aim of improving their effectiveness, but without proper labeling stating so. In addition to a public health problem, the consumption ofsupplements added with undeclared pharmacologically active substances also represents a career risk for professional athletes when it comes to doping in sport. In the present work, analytical methods based on liquid chromatography were developed for the detection of 19 pharmacologically active substances in dietary supplement samples at the levels of crosscontamination and adulteration. For this purpose, high performance liquid chromatography/diode array detector (HPLC-DAD) and liquid chromatography/tandem mass spectrometry (LC-MS/MS) were used. The investigated substances comprise of androgenic and anabolic effects (ie testosterone, testosterone propionate, testosterone decanoate, trenbolone, stanozolol, dehydroepiandrosterone, androstenedione, nandrolone decanoate, oxandrolone and metasterone), stimulant (ie caffeine), anorexigenic (ie sibutramine), diuretic (ie amiloride, bumetanide, furosemide, hydrochlorothiazide and chlorthalidone) and laxative (ie phenolphthalein). Among the sample preparation methods evaluated (Quechers and solidliquid extraction followed by a protein precipitation step), solid-liquid extraction using methanol as extraction solvent and ZnSO4 as the precipitating agent has been chosen as it has shown recovery values above 80% for all evaluated substances. The proposed analytical methods had limits of detection and quantification within the contamination range, they were also selective and linear showing r2 values higher than 0.99 in the concentration range of interest for all substances and accuracy within acceptable values. A representative sampling of dietary supplements marketed in Brazil, consisting of 230 samples, was analyzed and more than 25% have shown to be positive for caffeine (48), sibutramine (14), phenolphthalein (2) and furosemide (3), isolated or associated with each other. The methods developed used a simple sample preparation and presented satisfactory results for the investigation of possible adulteration or cross-contamination for the 19 of the substances of interest. From a total of 58 adulterated dietary supplements, only 11 could be considered adulterated by crosscontamination. The remaining are considered to be intentional additions by manufacturers in order to improve the efficiency of their products. The results presented in this study indicate the need for more effective measures by the health authorities towards the production and marketing of these products so that the general public is aware of their potential adulteration and the risks associated with their consumption

Antiproliferative Effect of Urera baccifera Leaves Against Ovarian Carcinoma Cell Line (OVCAR-3)

Abstract Natural products, especially phytochemicals, have been extensively studies and have exhibited important antiproliferative effects. The American native species Urera baccifera (L.) Gaudich. ex Wedd. (Urticaceae) is widely distributed in Brazil, where it is known as urtiga-vermelha or urtigão. The leaves are popularly used as anti-inflammatory, antirheumatic and in the treatment of gastric disorders. However, the antiproliferative potential of this plant against human tumor cells remain to be elucidated. In this study, we evaluated the antiproliferative effects of U. baccifera leaves extracts and fractions against a panel of human tumor cell lines in vitro besides a chemical evaluation of the most active sample by mass spectrometry (ESI-IT-MSn). The hydroalcoholic extract was inactive while dichloromethane extract showed moderate cytostatic activity against ovarian carcinoma cell line (OVCAR-3, GI50 = 1.5 μg/mL). More, the ethyl acetate and n-butanol fractions did not show important activity against tumour cell while the dichloromethane and hexane fractions showed moderate cytostatic activity against ovarian tumor cell line (OVCAR-3, GI50 = 12.7 and 9.4 μg/mL, respectively). Finally, the chemical profile evaluated by mass spectrometry (ESI-IT-MSn) allowed the detection of flavonoids in the HEU and hydroxylated fatty acid in DEU that can explain partially the biological effects observed. This is the first report of the antiproliferative effects of U. baccifera, and DEU has shown potential as a promising source of bioactive compounds.

A novel strategy for evaluation of natural products acting on the myeloperoxidase/hypochlorous acid system by combining high-performance liquid chromatography-photodiode array detection-chemiluminescence and ultrafiltration-mass spectrometry techniques.

Myeloperoxidase and its product hypochlorous acid are endogenous substances that are involved in the pathogenesis of many inflammatory diseases. In the present study, a novel evaluation strategy has been developed to screen for myeloperoxidase inhibitors and hypochlorous acid scavengers in natural products. The evaluation strategy uses two methods: a multi-hyphenated high-performance liquid chromatography-photodiode array detection-chemiluminescence online method, and an ultrafiltration-high-performance liquid chromatography-mass spectrometry method. Both were used for screening hypochlorous acid scavengers and myeloperoxidase inhibitors. After optimization of operating conditions, including pH of mobile phase and concentrations of myeloperoxidase, hypochlorous acid and luminol, the evaluation strategy was applied to Gardenia jasminoides Ellis (Rubiaceae) extract. Gardenia jasminoides Ellis (Rubiaceae) extract was found to both scavenge hypochlorous acid and inhibit myeloperoxidase. These different bioactivities originate from iridoid glycosides and quinic acid derivatives (25 hypochlorous acid scavengers) and crocetin derivatives (4 myeloperoxidase inhibitors). In a mouse model of acute lung injury, pulmonary histopathology showed that different constituents of Gardenia jasminoides Ellis (Rubiaceae) extract could also attenuate lung injury. Although the screening strategy has two arms, it is still simple, rapid, and effective. The strategy can also potentially be used to discriminate different activities of different constituents contained in the same natural product.

Liquid chromatographic nanofractionation with parallel mass spectrometric detection for the screening of plasmin inhibitors and (metallo)proteinases in snake venoms.

To better understand envenoming and to facilitate the development of new therapies for snakebite victims, rapid, sensitive, and robust methods for assessing the toxicity of individual venom proteins are required. Metalloproteinases comprise a major protein family responsible for many aspects of venom-induced haemotoxicity including coagulopathy, one of the most devastating effects of snake envenomation, and is characterized by fibrinogen depletion. Snake venoms are also known to contain anti-fibrinolytic agents with therapeutic potential, which makes them a good source of new plasmin inhibitors. The protease plasmin degrades fibrin clots, and changes in its activity can lead to life-threatening levels of fibrinolysis. Here, we present a methodology for the screening of plasmin inhibitors in snake venoms and the simultaneous assessment of general venom protease activity. Venom is first chromatographically separated followed by column effluent collection onto a 384-well plate using nanofractionation. Via a post-column split, mass spectrometry (MS) analysis of the effluent is performed in parallel. The nanofractionated venoms are exposed to a plasmin bioassay, and the resulting bioassay activity chromatograms are correlated to the MS data. To study observed proteolytic activity of venoms in more detail, venom fractions were exposed to variants of the plasmin bioassay in which the assay mixture was enriched with zinc or calcium ions, or the chelating agents EDTA or 1,10-phenanthroline were added. The plasmin activity screening system was applied to snake venoms and successfully detected compounds exhibiting antiplasmin (anti-fibrinolytic) activities in the venom of Daboia russelii, and metal-dependent proteases in the venom of Crotalus basiliscus. Graphical abstract ᅟ.