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The method describes pigment analysis from microalgae/phytoplankton extracts using electron-transfer Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (ET MALDI MS). Current microalgae/phytoplankton pigment analysis requires resource- and time-intensive chromatographic methods due to the broad polarity range of the target analytes. On the other hand, traditional MALDI MS chlorophyll analysis, using proton-transfer matrices such as 2,5-dihydroxybenzoic acid (DHB) or α-cyano-4-hydroxycinnamic acid (CHCA), results in central metal loss and phytol-ester cleavage. ET MALDI MS is an alternative for the rapid screening and detection of pigments in microalgae extracts.•MALDI matrices with ionization energies above 8.0 eV guarantee electron-transfer processes from photosynthetic and photoprotective pigments whose ionization energies lay below 7.5 eV.•ET MALDI MS pigment analysis agrees with data gathered from conventional chromatographic techniques (HPLC) and optical microscopy for pigment extracts from C. vulgaris cultures and freshwater phytoplankton samples.•The ET MALDI MS method allows fast and reliable detection of pigments in microalgae cultures and freshwater phytoplankton samples.

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Se presenta el caso de un paciente joven inmunocompetente, con antecedente de tuberculosis pulmonar, que acude al hospital por un cuadro clínico subagudo de fiebre persistente, baja de peso, disnea y abolición del murmullo vesicular. La tomografía de tórax mostró un extenso empiema en hemitórax izquierdo. Se le toman muestras para detección de gérmenes comunes y se le colocan un tubo de drenaje torácico y se inicia antibioticoterapia. La prueba de MALDI-TOF MS identificó a Parvimonas micra, una bacteria anaerobia, comensal de la flora oral, asociado a periodontitis severa, escasamente reportado en empiema pleural, especialmente, en personas inmunocompetentes. En la evaluación odontológica se realizó el diagnóstico de gingivitis y pericoronaritis de la tercera molar. El paciente evolucionó favorablemente. Se sugiere que, en casos de empiemas pleurales subagudos o crónicos, se debe considerar, además de las micobacterias, como agente etiológico al Parvimonas micra, y optar por exámenes como MALDI-TOF MS o secuenciamiento del 16S rRNA, colocación de tubo de tórax, cobertura antibiótica empírica y evaluación odontológica.

We present the case of a young immunocompetent patient, with a history of pulmonary tuberculosis, who attended the hospital with a subacute clinical picture of persistent fever, weight loss, dyspnea and abolition of vesicular murmur. Chest CT scan showed an extensive empyema in the left hemithorax. Samples were taken for detection of common germs. Then, a chest drainage tube was placed and antibiotic therapy started. The MALDI-TOF MS test identified Parvimonas micra, an anaerobic bacterium, commensal to the oral flora, associated with severe periodontitis, but rarely reported in cases of pleural empyema, especially in immunocompetent patients. Gingivitis and pericoronaritis of the third molar were diagnosed during oral evaluation. The patient progressed favorably. Parvimonas micra should be considered as a possible etiological agent in cases of subacute or chronic pleural empyema, in addition to mycobacteria. Tests such as MALDI-TOF MS or 16S rRNA sequencing, chest tube placement, empirical antibiotic coverage and an adequate oral evaluation should be considered in these cases.

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The aim of this study was to evaluate the effect of multilamellar vesicles (MLVs) of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) in co-culture with in vitro-produced bovine embryos (IVPEs). The stability of five concentrations of MLVs (1.0, 1.25, 1.5, 1.75, and 2.0 mM) produced using ultrapure water or embryonic culture medium with 24 or 48 h of incubation at 38.5 °C with 5% CO2 was assessed. In addition, the toxicity of MLVs and their modulation of the lipid profile of the plasma membrane of IVPEs were evaluated after 48 h of co-culture. Both media allowed the production of MLVs. Incubation (24 and 48 h) did not impair the MLV structure but affected the average diameter. The rate of blastocyst production was not reduced, demonstrating the nontoxicity of the MLVs even at 2.0 mmol/L. The lipid profile of the embryos was different depending on the MLV concentration. In comparison with control embryos, embryos cultured with MLVs at 2.0 mmol/L had a higher relative abundance of six lipid ions (m/z 720.6, 754.9, 759.0, 779.1, 781.2, and 797.3). This study sheds light on a new culture system in which the MLV concentration could change the lipid profile of the embryonic cell membrane in a dose-dependent manner.

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Moxidectin is an antiparasitic drug belonging to the class of the macrocyclic lactones, subgroup mylbemicins. It is used worldwide in veterinary practice, but little is known about its potential environmental risks. Thus, we used the zebrafish embryo as a model system to study the potential effects of moxidectin on aquatic non-target organisms. The analyses were performed in two experimental sets: (1) acute toxicity and apical endpoints were characterized, with biomarker assays providing information on the activity levels of catalase (CAT), glutathione S-transferase (GST), lactate dehydrogenase (LDH), and acetylcholinesterase (AChE); and (2) internal concentration and spatial distribution of moxidectin were determined using ultraperformance liquid chromatography quadrupole-time-of-flight mass spectrometry (UPLC-QToF-MS) and matrix-assisted laser desorption/ionization-MS imaging (MALDI-MSi). The acute toxicity to zebrafish embryos (96 hpf) appeared mainly as a decrease in hatching rates (EC50 = 20.75 µg/L). It also altered the enzymatic activity of biomarker enzymes related to xenobiotic processing, anaerobic metabolism, and oxidative stress (GST, LDH, and CAT, respectively) and strongly accumulated in the embryos, as internal concentrations were 4 orders of magnitude higher than those detected in exposure solutions. MALDI-MSi revealed accumulations of the drug mainly in the head and eyes of the embryos (72 and 96 hpf). Thus, our results show that exposure to moxidectin decreases hatching success by 96 h and alters biochemical parameters in the early life stages of zebrafish while accumulating in the head and eye regions of the animals, demonstrating the need to prioritize this compound for environmental studies.

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Abstract Background: Candida auris is an emerging yeast frequently reported as resistant to multiple antifungal drugs commonly used to treat Candida infections. This specie can colonize the patient's skin and has great ability for producing outbreaks in hospitals. C. auris is phylogenetically related to other Candida species, can be misidentified using conventional biochemical or commercial methods and requires specific technology for its identification. Case report: We report the first isolate of C. auris in Cali, Colombia, from a central venous catheter in a 37-year-old patient with rheumatoid arthritis and endocarditis who did not have symptoms of sepsis. The yeast was initially misidentified as C. haemulonii using the Phoenix system and subsequently identified as C. auris by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). The broth microdilution method was used to determine the minimum inhibitory concentration; the isolate was susceptible to fluconazole, itraconazole, voriconazole and amphotericin B. Conclusions: This report contributes to knowledge of the epidemiology of C. auris infections in individuals with underlying disease and describes an isolate with a behavior different from what is usually reported.

Resumen Antecedentes: Candida auris es una levadura emergente, informada con frecuencia como resistente a diversos antifúngicos usados comúnmente para tratar infecciones por Candida. Esta especie puede colonizar la piel y tiene gran capacidad de producir brotes en ambientes hospitalarios. Está filogenéticamente relacionada con otras especies de Candida, es mal identificada por los métodos bioquímicos o comerciales, y requiere tecnología específica para su identificación. Reporte de caso: Se informa el primer aislamiento de C. auris en Cali, Colombia en un paciente de 37 años con artritis reumatoide y endocarditis, sin síntomas de sepsis, a partir de la punta de catéter venoso central. La levadura inicialmente se identificó como C. haemulonii por el sistema Phoenix® y posteriormente como C. auris por espectrometría de masas desorción/ionización láser asistida por una matriz con detección de masas por tiempo de vuelo (MALDI-TOF MS). Se determinó la concentración inhibitoria mínima por el método de microdilución en caldo que mostró un aislamiento sensible a fluconazol, itraconazol, voriconazol y anfotericina B. Conclusión: Este informe contribuye al conocimiento de la epidemiología de las infecciones por C. auris en individuos con enfermedad subyacente y describe un aislamiento con un comportamiento diferente a lo indicado en otros estudios.

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Cinnamic acid derivatives, particularly α-cyano-4-hydroxycinnamic acid (E-α-cyano-4-hydroxycinnamic acid or (E)-2-cyano-3-(4-hydroxyphenyl)prop-2-enoate; CHCA), have been extensively used especially for protein and peptide analysis. Together with the introduction of ionic liquid MALDI matrix (ILM) started the study of applications of IL prepared with CHCA and a counter organic base (ie, aliphatic amines) in which CHCA moiety is the chromophore responsible of UV-laser absorption. Despite the extensive studies of norharmane (9H-pyrido[3,4-b]indole; nHo) applications as matrix and its peculiar basic properties in the ground and electronic excited state, nHo containing ILM was never tested in MALDI-MS experiments. This pyrido-indole compound was introduced as MALDI matrix 22 years ago for different applications including low molecular weight (LMW) carbohydrates (neutral, acidic, and basic carbohydrates). These facts encouraged us to use it as a base, for the first time, for ILM preparation. As a rational design of new IL MALDI matrices, E-α-cyanocinnamic acid.nHo and E-cinnamic acid.nHo were prepared and their properties as matrices studied. Their performance was compared with that of (a) the corresponding IL prepared with butylamine as basic component, (b) the corresponding crystalline E-α-cyanocinnamic and E-cinnamic acid, and (c) the classical crystalline matrices (2,5-dihydroxybenzoic acid, DHB; nHo) used in the analysis of neutral/sulfated carbohydrates. The IL DHB.nHo was tested, too. Herein, we demonstrate the outstanding performance for the IL CHCA.nHo for LMW carbohydrate in positive and negative ion mode (linear and reflectron modes). Sulfated oligosaccharides were detected in negative ion mode, and although the dissociation of sulfate groups was not completely suppressed the relative intensity (RI) of [M - Na]- peak was quite high. Additionally, to better understand the quite different performance of each IL tested as matrix, the physical and morphological properties in solid state were studied (optical image; MS image).

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BACKGROUND: Candida auris is an emerging yeast frequently reported as resistant to multiple antifungal drugs commonly used to treat Candida infections. This specie can colonize the patient's skin and has great ability for producing outbreaks in hospitals. C. auris is phylogenetically related to other Candida species, can be misidentified using conventional biochemical or commercial methods and requires specific technology for its identification. CASE REPORT: We report the first isolate of C. auris in Cali, Colombia, from a central venous catheter in a 37-year-old patient with rheumatoid arthritis and endocarditis who did not have symptoms of sepsis. The yeast was initially misidentified as C. haemulonii using the Phoenix system and subsequently identified as C. auris by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). The broth microdilution method was used to determine the minimum inhibitory concentration; the isolate was susceptible to fluconazole, itraconazole, voriconazole and amphotericin B. CONCLUSIONS: This report contributes to knowledge of the epidemiology of C. auris infections in individuals with underlying disease and describes an isolate with a behavior different from what is usually reported.

ANTECEDENTES: Candida auris es una levadura emergente, informada con frecuencia como resistente a diversos antifúngicos usados comúnmente para tratar infecciones por Candida. Esta especie puede colonizar la piel y tiene gran capacidad de producir brotes en ambientes hospitalarios. Está filogenéticamente relacionada con otras especies de Candida, es mal identificada por los métodos bioquímicos o comerciales, y requiere tecnología específica para su identificación. REPORTE DE CASO: Se informa el primer aislamiento de C. auris en Cali, Colombia en un paciente de 37 años con artritis reumatoide y endocarditis, sin síntomas de sepsis, a partir de la punta de catéter venoso central. La levadura inicialmente se identificó como C. haemulonii por el sistema Phoenix® y posteriormente como C. auris por espectrometría de masas desorción/ionización láser asistida por una matriz con detección de masas por tiempo de vuelo (MALDI-TOF MS). Se determinó la concentración inhibitoria mínima por el método de microdilución en caldo que mostró un aislamiento sensible a fluconazol, itraconazol, voriconazol y anfotericina B. CONCLUSIÓN: Este informe contribuye al conocimiento de la epidemiología de las infecciones por C. auris en individuos con enfermedad subyacente y describe un aislamiento con un comportamiento diferente a lo indicado en otros estudios.

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Yerba mate (YM) is massively produced and consumed as an infusion in South America and spreading all over the world. This product is obtained from dried leaves of Ilex paraguariensis Saint Hilaire, mixed with fragments of dried branches (sticks). For its commercialization, YM must have a minimum percentage of leaves because its presence determines YM quality and price. Till today, a mechanical methodology to determine the relative amount of components (sticks, leaves, and powder) is used. There is not any modern analytical method that provides information for quick characterization of the YM components. Typical saponin fingerprints for leaves and sticks were found by using ultraviolet matrix-assisted laser desorption ionization and ultraviolet laser desorption ionization mass spectrometry. Then, their possible application as useful tools for quick characterization of components of commercial YM (leaves and sticks) is presented. Furthermore, fingerprints obtained from authentic samples of Ilex paraguariensis and Ilex dumosa are also included and discussed. Each Ilex show typical saponin fingerprints for leaves and sticks.

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Tomato crops suffer attacks of various pathogens that cause large production losses. Late blight caused by Phytophthora infestans is a devastating disease in tomatoes because of its difficultly to control. Here, we applied metabolomics based on liquid chromatography⁻mass spectrometry (LC-MS) and metabolic profiling by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) in combination with multivariate data analysis in the early detection of late blight on asymptomatic tomato plants and to discriminate infection times of 4, 12, 24, 36, 48, 60, 72 and 96 h after inoculation (hpi). MALDI-MS and LC-MS profiles of metabolites combined with multivariate data analysis are able to detect early-late blight-infected tomato plants, and metabolomics based on LC-MS discriminates infection times in asymptomatic plants. We found the metabolite tomatidine as an important biomarker of infection, saponins as early infection metabolite markers and isocoumarin as early and late asymptomatic infection marker along the post infection time. MALDI-MS and LC-MS analysis can therefore be used as a rapid and effective method for the early detection of late blight-infected tomato plants, offering a suitable tool to guide the correct management and application of sanitary defense approaches. LC-MS analysis also appears to be a suitable tool for identifying major metabolites of asymptomatic late blight-infected tomato plants.

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In many amphibians, the granular glands can be grouped in special regions forming macroglands. This is the case of toads, characterized by the presence of a pair of parotoid macroglands, strategically located to give protection by poison release in case of attacks. The product secreted consists of a wide variety of chemical compounds including proteins, peptides, biogenic amines, toxic steroidal bufadienolides, and various alkaloids, depending on the species. In this work, using Rhinella arenarum, we have performed, for the first time, the matrix assisted-ultraviolet laser desorption/ionization mass spectrometry and tandem mass spectrometry characterization of the components of the secretion used as crude material, just suspended in MeOH (or MeCN). The crude sample as a whole (whole suspension) was spotted on the matrix assisted-ultraviolet laser desorption plate for analysis. Electrospray ionization-Orbitrap was used for cross-checking experiments. The pattern of signals obtained at m/z ranges 600 to 800 and 1200 to 1600 could be assigned as the argininyl bufadienolide esters fingerprint characteristic of female and male. Variation patterns for gender (female, male), age (non-reproductive, reproductive), and season (non-reproductive, reproductive) are described.

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Banana is one of the most popular fruits in the world but has been substantially impaired by Panama disease in the last years. Fusarium oxysporum f. sp. cubense (Foc) is the causal agent and colonizes banana cultivars from many subgroups with different aggressiveness levels, often leading to plant death while compromising new crops in infested areas. This study has evaluated the ability of MALDI-MS protein and lipid fingerprinting to provide intraspecies classification of Foc isolates and to screen biomolecules related to host-pathogen relationship. The MS data, when inspected via partial least square discriminant analysis (PLS-DA), distinguished the isolates by aggressiveness as well as by specific location and host. Although both lipids and proteins show discriminating tendencies, these differences were more clearly perceived via the protein profiles. Considering that Cavendish cultivar is the more resistant option to endure Foc presence in the field, the lipids and proteins related to this subgroup might have an important role in pathogen adaptation. This study reports a new application of MALDI-MS for the analysis of a banana pathogen with intraspecies classification ability. Graphical abstract MALDI-MS classified Foc isolates by aggressiveness level on banana revealing the additional influence of location and host cultivar on the expression of lipids and proteins.

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Although peptides are used as affinity chromatography ligands, they could be digested by proteases. Usually, peptide stability is evaluated in solution, which differs from the resin-bounded peptide behavior. Furthermore, the study of the degradation products requires purification steps before analysis. Here, we describe an easy method to assess immobilized peptide stability. Sample peptides were synthesized on hydroxymethylbenzamide-ChemMatrix resin. Peptidyl-resin beads were then incubated with solutions containing proteases. Peptides were detached from the solid support with ammonia vapor and analyzed by matrix-assisted laser desorption/ionization and electrospray ionization mass spectrometry, allowing the detection of the whole peptides as well as their C-terminal degradation products. The method allowed a fast evaluation of peptide ligand stability in solid phase towards proteases that may be present in the crude sample before their use as ligands in affinity chromatography. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

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Since introduction of sinapinic acid (SA) and α-cyano-4-hydroxycinnamic acid as matrices, successful application of matrix-assisted laser desorption/ionization mass spectrometry started for protein/polypeptides. Both show some limitations in short peptide analysis because matrix clusters are quite abundant. Cinnamics currently used are E-cinnamics. Here, Z-SA as matrix for peptides is studied and compared with E-SA and α-cyano-4-hydroxycinnamic acid. Minor number of clusters is always observed in the low m/z region allowing the detection of short peptides. The results here described show that this novel matrix is a tool of choice for direct, rapid and sensitive detection of hydrophilic and hydrophobic peptides. Copyright © 2017 John Wiley & Sons, Ltd.

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In this study, we describe the characterization of the peptide profile in commercial Prato cheese by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) and capillary electrophoresis (CE). Ten commercial Prato cheese brands were characterized via their physicochemical composition and subjected to fractionation according to solubility at pH 4.6. The pH 4.6 insoluble fraction was evaluated by CE, whereas MALDI-MS was applied to the fraction soluble at pH 4.6 and in 70% ethanol. CE revealed a characteristic pattern of hydrolysis, with formation of para-κ-casein, hydrolysis of αs1 -casein at the Phe23 - Phe24 bond, and hydrolysis of ß-casein. For the MALDI-MS data, a complex peptide profile was observed, with the identification of 44 peptides previously reported (24 peptides from αs1 -casein, 14 from ß-casein, 3 from κ-casein, and 3 from αs2 -casein). It was also observed that cheeses with salt-in-moisture content greater than 5% showed an accumulation of a bitter-tasting peptide (m/z 1536, αs1 -CN f1-13), suggesting a relationship between the higher salt concentration and the abundance of this peptide. In conclusion, the results showed that even commercial cheeses produced with different raw material and processing conditions showed very similar peptide profiles when assessed at the molecular level, and only 9 peptides were responsible for discrimination of cheeses.

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Phospholipid metabolism and signaling influences on early pregnancy events in cattle are unknown. This study aimed to characterize global phospholipid composition of oviduct and uterus during early diestrus in a model of contrasting embryo receptivity. Beef cows were treated to ovulate a larger (LF-LCL group, associated with greater receptivity) or smaller (SF-SCL group) follicle and, consequently, to present greater or smaller plasma concentrations of estradiol during proestrus-estrus, as well as progesterone during early diestrus. Oviduct and uterus (4 days after gonadotropin-releasing hormone-induced ovulation; D4) as well as the uterus (D7) were collected, and lipid profiles were monitored by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). This technique allowed the identification and tissue localization of sphingomyelins (SM), phosphatidylcholines (PC), ceramides (Cer), and phosphatidylethanolamines (PE). Multivariate statistics were used to separate samples into groups with distinctly different phospholipid profiles in the uterus at D4 and D7. Different abundance of ions corresponding to specific lipids were detected on D4 (Cer [42:1], PC [31:0], PC [32:1], PC [34:4], and PC [36:4] greater for LF-LCL group; and PC [38:7], PC [38:5], PC [38:4], PC [40:7], and PC [40:6] greater for SF-SCL group) and D7 (SM [34:2], SM [34:1], PC [32:1], and PC [35:2] greater for LF-LCL group). The MALDI-MS imaging showed the spatial distributions of major phospholipids. In conclusion, distinct phospholipid profiles were associated with animals treated to show contrasting receptivity to the embryo. Functional roles of the identified phospholipids on uterine function and preimplantation embryo development deserve further studies.

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Combinatorial library screening coupled to mass spectrometry (MS) analysis is a practical approach to identify useful peptides. Cyclic peptides can have high biological activity, selectivity, and affinity for target proteins, and high stability against proteolytic degradation. Here we describe two strategies to prepare combinatorial libraries suitable for MS analysis to accelerate the discovery of cyclic peptide structures. Both approaches use ChemMatrix resin and the linker 4-hydroxymethylbenzoic acid. One strategy involves the synthesis of a one-bead-two-peptides library in which each bead contains both the cyclic peptide and its linear counterpart to facilitate MS analysis. The other protocol is based on the synthesis of a cyclic depsipeptide library in which a glycolamidic ester group is incorporated by adding glycolic acid. After library screening, the ring is opened and the peptide is released simultaneously for subsequent MS analysis. © 2016 by John Wiley & Sons, Inc.

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The search for new nano-systems for targeted biomedical applications and controlled drug release has attracted significant attention in polymer chemistry, pharmaceutics, and biomaterial science. Controlled drug delivery has many advantages over conventional drug administration, such as reduction of side effects, maintaining a stable plasma level concentration and improving the quality of life of patients. In this study, PAMAM G5 dendrimers and PAMAM G5-folic acid conjugates (PAMAM G5-FA) are synthesized and characterized by mass spectrometry (MALDI-MS). Controlled release studies at different pH values show that PAMAM G5-FA is a good candidate as a carrier for tramadol and morphine, while mathematical modeling is conducted, suggesting that the release process is governed by a diffusion mechanism. In addition, using molecular dynamics simulations, we investigate the structural and energetic properties that facilitate the encapsulation of tramadol and morphine by unmodified and functionalized PAMAM-G5 dendrimers at low, neutral and high pH. Our results correlate well with experimental data, confirming that tramadol and morphine may be encapsulated both by functionalized PAMAM dendrimers and unmodified PAMAM. Moreover, the simulations further reveal that hydrogen-bond and electrostatic interactions govern the affinity the dendrimers for both drugs. This information is envisioned to prove useful for the encapsulation of other drugs and for the design of novel functionalized dendrimers.

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Lipid pathways play important biological roles in mammalian embryology, directing early developmental pathways to differentiation. Phospholipids and triglycerides, among others, are the main composing lipids of zona pellucida in several embryo species. Lipid analysis in embryos by mass spectrometry usually requires sample preparation and/or matrix application. This novel approach using silica plate laser desorption/ionization mass spectrometry imaging (SP-LDI-MSI) allows direct single-cell imaging and embryo region discrimination with no matrix coating. Its application is herein described for two- and eight-cell embryos. Lipid biomarkers for blastomere and intact zona pellucida are reported and corroborated by both fragmentation reactions (MS/MS) and images. Results obtained in this work are understood to be of great use for further developments on in vitro bovine fertilization. Since much of the processes can be monitored by characteristic biomarkers, it is now possible to precisely identify cell division errors during early embryo stages, as well as evaluate pre-implantation conditions.

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It was reported the potential of MALDI-MS for the characterization of lipid species present in a single equine embryo, and studied some lipid structures detected by collision induced dissociation (CID) experiments. In the positive ion mode spectrum, it were observed mostly protonated and sodiated species of sphingomyelins (SM), phosphatidylcholines (PC) and triacylglycerols (TAG). In the negative ion mode, it were observed phosphatidylethanolamines (PE) and phosphatidylinositols (PI). MS/MS spectrum of most intense lipid ions was performed to show MALDI-MS/MS structural information potential. MS/MS spectrum in the positive mode of m/z 760.6 (attributed as PC34:1) depicted characteristic PC fragments of m/z 184.1 (choline polar head), and the neutral loss (NL) of 183 (phosphorylcholine). For the ion of m/z 766.6 (attributed as PE 38:5), we observed the NL of 140, characteristic of PE. For the ion of m/z 808.7 (attributed as PC 38.5), besides the fragment at m/z 184.1 at the NL of 183, it was possible to observe the loss of trimethylamine (ion of m/z 749.6), and the cyclophosphane (ion of m/z 147.0). Finally, for the negative ion mode, we isolated and fragmented the ion at m/z 863.6, which was attributed as PI 36:1 due to the presence of m/z 153 (glycerol phosphate – H2 O-H), 223 (phospho inositol – 2H2 O-H), 241 (phospho inositol – H2 O-H), 281 (oleic acid), and 581.3 (lysophosphoinositol – H2 O-H). It was concluded that MALDI-MS allowed the detection of a broad range of PC, SM, PE, PI and TAG lipid species, as well as a fast and confident characterization of lipid structures from a single equine embryo.

É relatado o potencial da técnica de MALDI-MS para caracterizar espécies de lipídios presentes em um único embrião equino e estudadas algumas estruturas lipídicas detectadas por dissociação induzida por colisão (CID). No espectro de modo íon positivo, foram observadas espécies, principalmente, protonadas e sodiadas de esfingomielinas (SM), fosfatidileolinas (PC) e triacilgliceróis (TAG). No modo negativo, foram observadas fosfatidiletanolaminas (PE) e fosfatidilinositos (PI). Espectros de íons de lípidos com maior intensidade foram utilizados para demonstrar o potencial da informação estrutural por MALDI-MS/MS. O espectro no modo positivo de m/z (massa sobre carga) 760,6 (atribuída como PC34:1) apresentou características de fragmentos PC de m/z 184,1 (denominada cabeça polar de colina), além de perda neutral (NL) de m/z 183 (fosforilcolina). Para o íon de m/z 766,6 (atribuída como PE38:5), observou-se a NL de 140, característica do PE. Para o íon de m/z 808,7 (38,5 atribuído como PC), além do fragmento m/z 184,1 na NL de 183, foi possível observar a perda de trimetilamina (íon de m/z 749,6) e o ciclofosfano (íon de m/z 147,0). Finalmente, para o modo de íon negativo, foram isolados e fragmentados o íon de m/z 863,6 que foi atribuído como PI36:1, devido à presença de m/z 153 (fosfato de glicerol – H2 O-H ), 223 (inositol fosfo - 2H2 O-H) , 241 (fosfoinositol – H2 O-H), 281 (ácido oleico) e 581,3 (lisofosfoinositol – H2 O+H). Foi concluído que a MALDI - MS permite a detecção de uma ampla gama de espécies de PC, SM, PE, PI e TAG lipídicas, bem como a caracterização rápida e confiante de estruturas lipídicas a partir de um único embrião equino.

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RESUMO

It was reported the potential of MALDI-MS for the characterization of lipid species present in a single equine embryo, and studied some lipid structures detected by collision induced dissociation (CID) experiments. In the positive ion mode spectrum, it were observed mostly protonated and sodiated species of sphingomyelins (SM), phosphatidylcholines (PC) and triacylglycerols (TAG). In the negative ion mode, it were observed phosphatidylethanolamines (PE) and phosphatidylinositols (PI). MS/MS spectrum of most intense lipid ions was performed to show MALDI-MS/MS structural information potential. MS/MS spectrum in the positive mode of m/z 760.6 (attributed as PC34:1) depicted characteristic PC fragments of m/z 184.1 (choline polar head), and the neutral loss (NL) of 183 (phosphorylcholine). For the ion of m/z 766.6 (attributed as PE 38:5), we observed the NL of 140, characteristic of PE. For the ion of m/z 808.7 (attributed as PC 38.5), besides the fragment at m/z 184.1 at the NL of 183, it was possible to observe the loss of trimethylamine (ion of m/z 749.6), and the cyclophosphane (ion of m/z 147.0). Finally, for the negative ion mode, we isolated and fragmented the ion at m/z 863.6, which was attributed as PI 36:1 due to the presence of m/z 153 (glycerol phosphate H2 O-H), 223 (phospho inositol 2H2 O-H), 241 (phospho inositol H2 O-H), 281 (oleic acid), and 581.3 (lysophosphoinositol H2 O-H). It was concluded that MALDI-MS allowed the detection of a broad range of PC, SM, PE, PI and TAG lipid species, as well as a fast and confident characterization of lipid structures from a single equine embryo.(AU)

É relatado o potencial da técnica de MALDI-MS para caracterizar espécies de lipídios presentes em um único embrião equino e estudadas algumas estruturas lipídicas detectadas por dissociação induzida por colisão (CID). No espectro de modo íon positivo, foram observadas espécies, principalmente, protonadas e sodiadas de esfingomielinas (SM), fosfatidileolinas (PC) e triacilgliceróis (TAG). No modo negativo, foram observadas fosfatidiletanolaminas (PE) e fosfatidilinositos (PI). Espectros de íons de lípidos com maior intensidade foram utilizados para demonstrar o potencial da informação estrutural por MALDI-MS/MS. O espectro no modo positivo de m/z (massa sobre carga) 760,6 (atribuída como PC34:1) apresentou características de fragmentos PC de m/z 184,1 (denominada cabeça polar de colina), além de perda neutral (NL) de m/z 183 (fosforilcolina). Para o íon de m/z 766,6 (atribuída como PE38:5), observou-se a NL de 140, característica do PE. Para o íon de m/z 808,7 (38,5 atribuído como PC), além do fragmento m/z 184,1 na NL de 183, foi possível observar a perda de trimetilamina (íon de m/z 749,6) e o ciclofosfano (íon de m/z 147,0). Finalmente, para o modo de íon negativo, foram isolados e fragmentados o íon de m/z 863,6 que foi atribuído como PI36:1, devido à presença de m/z 153 (fosfato de glicerol H2 O-H ), 223 (inositol fosfo - 2H2 O-H) , 241 (fosfoinositol H2 O-H), 281 (ácido oleico) e 581,3 (lisofosfoinositol H2 O+H). Foi concluído que a MALDI - MS permite a detecção de uma ampla gama de espécies de PC, SM, PE, PI e TAG lipídicas, bem como a caracterização rápida e confiante de estruturas lipídicas a partir de um único embrião equino.(AU)

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