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1.
Biomed Chromatogr ; 36(4): e5340, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35043434

RESUMO

In this study, different injection solutions containing opioid and nonopioid compounds used for patient-controlled analgesia in hospice and palliative care were evaluated in terms of analyte stability. Investigated injection solutions contained different combinations of morphine, hydromorphone, metamizole and esketamine. For the practical implementation, samples from infusion pumps were daily drawn over a period of 7 days at 22 and 37°C. Quantitative measurements were performed on a high-performance liquid chromatography system with ultraviolet detection applying a validated analytical method. All compounds apart from morphine showed no evident changes in concentration. However, a significant loss of morphine was observed for injection mixtures containing both morphine and metamizole at 37°C. After 7 days, only 72% of the initially measured morphine concentration was measured in the binary and 77% in the ternary mixture. Furthermore, an additional compound was detected that could represent the morphine-metamizole-adduct, "metamorphine". Based on these results, a significantly reduced morphine concentration must be expected after only 3 days if an injection solution mixture containing both morphine and metamizole is administered to a patient at 37°C. Since the analgesic effects of morphine-metamizole adducts have not yet been thoroughly investigated, further clinical studies are necessary before accurate conclusions can be drawn in this regard.


Assuntos
Hospitais para Doentes Terminais , Hidromorfona , Analgesia Controlada pelo Paciente , Analgésicos Opioides , Dipirona , Humanos , Hidromorfona/química , Ketamina , Morfina , Cuidados Paliativos/métodos
2.
Molecules ; 27(3)2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35163862

RESUMO

Truffles represent the best known and most expensive edible mushroom. Known as Ascomycetes, they belong to the genus Tuber and live in symbiosis with plant host roots. Due to their extraordinary taste and smell, truffles are sold worldwide for high prices of up to 3000-5000 euros per kilogram (Tuber magnatum PICO). Amongst black truffles, the species Tuber melanosporum VITTAD. is highly regarded for its organoleptic properties. Nonetheless, numerous different sorts of black truffle are offered at lower prices, including Tuber aestivum VITTAD., Tuber indicum and Tuber uncinatum, which represent the most frequently consumed types. Because truffles do not differ visually for inexperienced consumers, food fraud is likely to occur. In particular, for the highly prized Tuber melanosporum, which morphologically forms very similar fruiting bodies to those of Tuber indicum, there is a risk of fraud via imported truffles from Asia. In this study, 126 truffle samples belonging to the four mentioned species were investigated by four different NIR instruments, including three miniaturized devices-the Tellspec Enterprise Sensor, the VIAVI solutions MicroNIR 1700 and the Consumer Physics SCiO-working on different technical principles. Three different types of measurement techniques were applied for all instruments (outer shell, rotational device and fruiting body) in order to identify the best results for classification and quality assurance in a non-destructive manner. Results provided differentiation with an accuracy up to 100% for the expensive Tuber melanosporum from Tuber indicum. Classification between Tuber melanosporum, Tuber indicum, Tuber aestivum and Tuber uncinatum could also be achieved with success of 100%. In addition, quality monitoring including discrimination between fresh and frozen/thawed, and prediction of the approximate date of harvesting, was performed. Furthermore, feasibility studies according to the geographical origin of the truffle were attempted. The presented work compares the performance for prediction and quality monitoring of portable vs. benchtop NIR devices and applied measurement techniques in order to be able to present a suitable, accurate, fast, non-destructive and reliable method for consumers.


Assuntos
Ascomicetos/química , Ascomicetos/classificação , Técnicas Biossensoriais/métodos , Contaminação de Alimentos/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Ascomicetos/isolamento & purificação , Especificidade da Espécie
3.
Toxicol Appl Pharmacol ; 430: 115727, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34543670

RESUMO

Electronic cigarettes (e-cigarettes) have gained increasing popularity in recent years, mostly because they are supposed to be less harmful than regular cigarettes. Therefore, it is highly imperative to investigate possible noxious effects to protect the consumers. E-liquids consist of propylene glycol, glycerol, aroma compounds and sweeteners. One of these sweeteners is a chlorinated version of sucrose, namely sucralose. The aim of this work was to investigate degradation products of sucralose in the presence of propylene glycol and glycerol at different temperatures of commercially available e-cigarettes. Chemical analysis and biological tests were simultaneously performed on e-liquid aerosol condensates. The results of the chemical analysis, which was executed by employing GC-MS/GC-FID, demonstrated high amounts of various chloropropanols. The most abundant one is extremely toxic, namely 3-chloropropane-1,2-diol, which can be detected at concentrations ranging up to 10,000 mg/kg. Furthermore, a cytotoxicity investigation of the condensates was performed on HUVEC/Tert2 cells in which metabolic activity was determined by means of resazurin assay. The cellular metabolic activity significantly decreased by treatment with e-liquid aerosol condensate. Due to the results of this study, we advise against the use of sucralose as sweetener in e-liquids.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Glicerol/toxicidade , Propilenoglicol/toxicidade , Sacarose/análogos & derivados , Edulcorantes/toxicidade , Vaping/efeitos adversos , alfa-Cloridrina/toxicidade , Células Cultivadas , Qualidade de Produtos para o Consumidor , Estabilidade de Medicamentos , Glicerol/química , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Propilenoglicol/química , Medição de Risco , Sacarose/química , Sacarose/toxicidade , Edulcorantes/química , Temperatura , Testes de Toxicidade , Volatilização , alfa-Cloridrina/química
4.
Chem Res Toxicol ; 34(12): 2522-2533, 2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34879203

RESUMO

Capsaicin, primarily known as the pungent ingredient in hot peppers, is rapidly metabolized in the human body by enzymatic processes altering the pharmacological as well as toxicological properties. Herein, the oxidative transformation of capsaicin was investigated in vitro with electrochemistry as well as human liver microsomal incubations. The reaction mixtures were analyzed with liquid chromatography-mass spectrometry. Structure elucidation involved accurate mass measurements and multistage tandem mass spectrometry experiments. In total, 126 transformation products were detected. Electrochemistry provided evidence for 101 transformation products and the microsomal incubations for 46 species. 21 compounds were observed with both approaches. Identified oxidative pathways likely occurring during the phase I metabolism included dehydrogenation, O-demethylation, and hydroxylation reactions as well as combinations thereof. Furthermore, trapping of reactive intermediates either with glutathione or with electrochemically activated ribonucleosides provided evidence for the possible production of phase II metabolites and covalent adducts with a genetic material. Evidence for the occurrence of some capsaicin metabolites in humans was obtained by urine screening.


Assuntos
Capsaicina/metabolismo , Técnicas Eletroquímicas , Capsaicina/urina , Cromatografia Líquida , Voluntários Saudáveis , Humanos , Espectrometria de Massas , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Oxirredução
5.
Molecules ; 26(16)2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34443395

RESUMO

Recently polyphenols attracted great interest in the field of food and nutrition as well as in the pharmaceutical and cosmetics industries due to their health benefits through antioxidative behavior in the human body. However, because of the high number of compounds characterized as phenols and their structural diversity, quantification of polyphenols turns out to be a highly complex task. Although, a wide variety of analytical methods are used for the determination of total polyphenolic content, they are all found to be lacking in a variety of different tasks, such as their limits of detection and quantification, repeatability, accuracy and specificity. For this reason, a novel approach combining the advantages of solid phase purification, near infrared analysis and multivariate data analysis was investigated for the prediction of total polyphenolic content, suitable for a wide range of sample matrices. Dispersive solid phase extraction was performed and optimized using polyvinylpyrrolidone as sorbent, known to selectively bind polyphenols. Near-infrared detection of adsorbed polyphenols was carried out subsequently. Furthermore, the method was in-house validated, examining selectivity, repeatability and accuracy, working range, as well as multivariate limit of detection and limit of quantification, comparing it with two routinely used methods-namely, Folin-Ciocalteu photometric assay and Löwenthal titration. The novel established method was applied for the prediction of total polyphenolic content in tea and wine samples.


Assuntos
Polifenóis/isolamento & purificação , Povidona/química , Extração em Fase Sólida , Antioxidantes/química , Humanos , Polifenóis/química
6.
Int Rev Psychiatry ; 32(7-8): 616-624, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32885690

RESUMO

Creativity is the ability to produce something novel and useful that is a valuable contribution to a specific domain. It is a significant common factor in most forms of psychotherapy. Accordingly, it is essential to investigate its role both in psychotherapy in general and in specific approaches like relational, cognitive-behavioural, psychodynamic, systemic, and existential psychotherapy. Positive psychology in particular has pointed up the usefulness of creativity in psychotherapy. Here we draw upon a case example to show how the creative discovery of novel and useful solutions takes place in different dimensions: relational, behavioural, psychodynamic, systemic and existential. The case description demonstrates how principles of positive psychology are useful in many realms of psychotherapy. We propose an integrated model of psychotherapy that brings together different psychotherapeutic methods and is based on interdisciplinary creativity research. The integration of neuroscientific, psychological and cultural findings produced by creativity research can be expected to lead to a deeper understanding of psychotherapeutic, positive-psychological, and creative processes.


Assuntos
Criatividade , Psicologia Positiva , Psicoterapia , Adolescente , Feminino , Humanos
7.
Biomed Chromatogr ; 34(3): e4761, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31758585

RESUMO

During recent years, the number of consumers using so-called e-cigarettes, which are electrical devices to aerosolize a liquid consisting of propylene glycol, glycerol, optional nicotine and flavoring chemicals, has been increasing. Aromas vary from common flavors such as mint to more unusual flavors such as buttermilk or pepperoni pizza. Consumers today can buy e-concentrates that consist of propylene glycol and aroma to blend their own desired flavor at home. Little is known about the composition and concentration of various aroma molecules in the different e-liquids and e-concentrates. In addition, the process of EU-wide regulation is still ongoing. The aim of this research study was to identify and quantify possible undesirable aroma compounds in e-liquids and e-concentrates. Flavoring chemicals such as estragole, benzaldehyde and cinnamaldehyde were quantified. The measurements were carried out on a GC-MS system. The results show the presence of highly concentrated flavoring compounds and limonene oxide in lemon-flavored e-concentrates. In the final step, samples and single-aroma standards were tested for their toxicity to HUVEC/Tert2 cells, where some single-flavoring chemicals such as cinnamic aldehyde revealed significant toxic effects.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Aromatizantes/toxicidade , Cromatografia Gasosa-Espectrometria de Massas/métodos , Metaboloma/efeitos dos fármacos , Odorantes , Acroleína/análogos & derivados , Acroleína/toxicidade , Derivados de Alilbenzenos , Anisóis/toxicidade , Benzaldeídos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Testes de Toxicidade
8.
Sensors (Basel) ; 20(17)2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32887485

RESUMO

Elderberry (Sambucus nigra L., fructus) is a very potent herbal drug, deriving from traditional European medicine (TEM). Ripe elderberries are rich in anthocyanins, flavonols, flavonol esters, flavonol glycosides, lectins, essential oils, unsaturated fatty acids and vitamins. Nevertheless, unripe elderflower fruits contain a certain amount of sambunigrin, a toxic cyanogenic glycoside, whose concentration decreases in the ripening process. Therefore, quality assurance must be carried out. The standard method described in literature is the photometric determination (pH-differential method) of the total anthocyanin content (TAC) that is the highest when the berries are ripe. The drawback of the pH-differential method is the extensive sample preparation and the low accuracy of the method. Therefore, the goal of this publication was to develop a fast non invasive near-infrared (NIR) method for the determination of TAC in whole berries. TAC of elderberries was measured using pH-differentiation method where TAC values of 632.87 mg/kg to 4342.01 mg/kg were measured. Additionally, cyanidin-3-O-glucoside, cyanidin-3-O-sambubioside and cyanidin-3-O-sambubioside-5-O-glucoside which represent more than 98% of TAC in elderberry were quantified using ultra high performance liquid chromatography-multiple wavelength detection-ultra high resolution-quadrupole-time of flight-mass spectrometry (UHPLC-MWD-UHR-Q-TOF-MS) and their sum parameter was determined, ranging between 499.43 mg/kg and 8199.07 mg/kg. Using those two methods as reference, whole elderberries were investigated by NIR spectroscopy with the Büchi NIRFlex N-500 benchtop spectrometer. According to the constructed partial least squares regression (PLSR) models the performance was as follows: a relative standard deviation (RSDPLSR) of 13.5% and root mean square error of calibration (RMSECV/RMSEC) of 1.31 for pH-differentiation reference and a RSDPLSR of 12.9% and RMSECV/RMSEC of 1.28 for the HPLC reference method. In this study, we confirm that it is possible to perform a NIR screening for TAC in whole elderberries. Using quantum chemical calculations, we obtained detailed NIR band assignments of the analyzed compounds and interpreted the wavenumber regions established in PLSR models as meaningful for anthocyanin content. The NIR measurement turned out to be a fast and cost-efficient alternative for the determination of TAC compared to pH-differential method and UHPLC-MWD-UHR-Q-TOF-MS. Due to the benefit of no sample preparation and extraction the technology can be considered as sustainable green technology. With the above mentioned inversely proportional ratio of TAC to total amount of toxic cyanogenic glycosides, NIR proves to be a reliable screening method for the ideal harvest time with maximal content of TAC and lowest content of cyanogenic glycosides in elderberry.


Assuntos
Sambucus , Antocianinas/análise , Cromatografia Líquida de Alta Pressão , Frutas/química , Espectroscopia de Luz Próxima ao Infravermelho
9.
Anal Bioanal Chem ; 411(14): 3029-3035, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30879113

RESUMO

The aim of this work was to evaluate the evaporation behavior of certain aroma compounds found in e-liquids. Since an e-liquid is evaporated, the aroma present can reach the lungs and could be absorbed into the body which may have long-term health effects above critical concentrations. Due to a lack in regulations, the sort and concentration of the compounds in sold e-liquids can vary. To capture the aroma compounds in the vapor, a smoking machine was developed. The resulting data represent the amount of aroma reaching the consumers' lungs. The influence of the e-cigarette temperature, ranging from 100 to 315 °C, on the evaporation of benzaldehyde, estragole, and different terpenoids was examined. Additionally, the effect of the liquid base composition on the amount of aroma in the vapor was compared using the analysis of variances. The influence of high temperature, the type of e-cigarette, and the atomizer coil material, which could lead to oxidation of limonene and linalool in the vapor, is shown here.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Cromatografia Gasosa-Espectrometria de Massas/métodos , Odorantes/análise , Compostos Orgânicos/química , Monoterpenos Acíclicos , Derivados de Alilbenzenos , Anisóis/química , Benzaldeídos/química , Desenho de Equipamento , Temperatura Alta , Limoneno/química , Monoterpenos/química , Oxirredução , Transição de Fase , Reprodutibilidade dos Testes , Fumar Tabaco
10.
Biomed Chromatogr ; 33(9): e4567, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31042298

RESUMO

A poly(dibenzo-18-crown-6) was used as a new solid-phase extraction material for the selective enrichment of phosphopeptides. Isolation of phosphopeptides was achieved based on specific ionic interactions between poly(dibenzo-18-crown-6) and the phosphate group of phosphopeptides. Thus, a method was developed and optimized, including loading, washing and elution steps, for the selective enrichment of phosphopeptides. To assess this potential, tryptic digest of three proteins (α- casein, ß-casein and ovalbumin) was applied on poly(dibenzo-18-crown-6). The nonspecific products were removed by centrifugation and washing. The spectrometric analysis was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Highly selective enrichment of both mono- and multiphosphorylated peptides was achieved using poly(dibenzo-18-crown-6) as solid-phase extraction material with minimum interference from nonspecific compounds. Furthermore, evaluation of the efficiency of the poly(dibenzo-18-crown-6) was performed by applying the digest of egg white. Finally, quantum mechanical calculations were performed to calculate the binding energies to predict the affinity between poly(dibenzo-18-crown-6) and various ligands. The newly identified solid-phase extraction material was found to be a highly efficient tool for phosphopeptide recovery from tryptic digest of proteins.


Assuntos
Éteres de Coroa/química , Fosfopeptídeos/isolamento & purificação , Extração em Fase Sólida/métodos , Modelos Moleculares , Fragmentos de Peptídeos/análise , Fragmentos de Peptídeos/química , Fosfopeptídeos/análise , Fosfopeptídeos/química , Polímeros/química , Proteômica , Extração em Fase Sólida/instrumentação
11.
J Sep Sci ; 41(3): 704-712, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29134782

RESUMO

We present a novel method for the quantitative determination of the clean-up efficiency to provide a calculated parameter for peak purity through iterative fitting in conjunction with design of experiments. Rosemary extracts were used and analyzed before and after solid-phase extraction using a self-fabricated mixed-mode sorbent based on poly(N-vinylimidazole/ethylene glycol dimethacrylate). Optimization was performed by variation of washing steps using a full three-level factorial design and response surface methodology. Separation efficiency of rosmarinic acid from interfering compounds was calculated using an iterative fit of Gaussian-like signals and quantifications were performed by the separate integration of the two interfering peak areas. Results and recoveries were analyzed using Design-Expert® software and revealed significant differences between the washing steps. Optimized parameters were considered and used for all further experiments. Furthermore, the solid-phase extraction procedure was tested and compared with commercial available sorbents. In contrast to generic protocols of the manufacturers, the optimized procedure showed excellent recoveries and clean-up rates for the polymer with ion exchange properties. Finally, rosemary extracts from different manufacturing areas and application types were studied to verify the developed method for its applicability. The cleaned-up extracts were analyzed by liquid chromatography with tandem mass spectrometry for detailed compound evaluation to exclude any interference from coeluting molecules.


Assuntos
Cromatografia Líquida de Alta Pressão , Cinamatos/análise , Depsídeos/análise , Extratos Vegetais/análise , Extração em Fase Sólida , Espectrometria de Massas em Tandem , Imidazóis , Metacrilatos , Modelos Estatísticos , Distribuição Normal , Óleos Voláteis/análise , Polímeros , Reprodutibilidade dos Testes , Ácido Rosmarínico
12.
Psychother Psychosom Med Psychol ; 68(2): 66-74, 2018 02.
Artigo em Alemão | MEDLINE | ID: mdl-29169198

RESUMO

"Sense of coherence" (SOC) plays an essential role in the maintenance or recovery of health, according to the salutogenetic approach of Aaron Antonovsky. Empirical studies provide evidence of significant links between sense of coherence and different indicators of mental health. In the present study, the effectivity of an integrative counselling concept for the promotion of sense of coherence, reduction of mental distress and improvement of satisfaction with life was tested in a sample of 153 clients and patients. Correlations of SOC with mental distress and satisfaction with life and studies indicate a strong association. After psychosocial counselling according to the integrative ABCDE-model, significant pre-/post- changes with moderate to high effect sizes could be achieved. These findings bring important implications for the modifiability of the sense of coherence and provide evidence that the integrative ABCDE-model of psychosocial counseling might be effective. Correlations between ratings of the dimensions of the model and pre-/post changes are discussed.


Assuntos
Aconselhamento , Satisfação Pessoal , Senso de Coerência , Estresse Psicológico/psicologia , Adulto , Feminino , Humanos , Masculino , Transtornos Mentais/psicologia , Transtornos Mentais/terapia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica , Apoio Social , Adulto Jovem
13.
Anal Chem ; 89(19): 10232-10238, 2017 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-28849910

RESUMO

Polymeric monoliths fabricated in tips with embedded materials of choice are important in separation science. Polymeric backbone however interferes in the enrichment and thus affects efficiency. This work focuses on the in-tip fabrication of lanthanum oxide porous monolith and its application in the enrichment of phosphorylated peptides and lipids. Polycondensation reaction uses an aqueous solution of LaCl3·7H2O with N-methyl formamide as porogen and propylene oxide as initiator. The aging time of monolith and temperature condition for the reaction are optimized to attain porous monolithic tip. A comparison of (i) solid phase batch extraction using La2O3, (ii) La2O3 embedded in poly(glycidyl methacrylate (GMA)/divinylbenzene (DVB)) tip, and (iii) pure La2O3 monolithic tip shows improved enrichment efficiency in the case of pure La2O3 monolithic tip. The monolithic tip achieves selectivity of 1:4500 as compared to solid phase extraction (SPE)(1:3500) and limit of detection down to 0.25 fmol. The in-tip La2O3 monolith strategy has better batch to batch reproducibility, reduced time of enrichment, and ease of operation in comparison to solid phase batch extraction. The developed strategy enriches phospho- content from biological samples like phosvitin and lipovitellin from egg yolk and phospholipids/phosphopeptides from human serum. The enriched phospho- moieties are analyzed by matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) except the phospholipids where laser desorption ionization (LDI)-MS is employed.


Assuntos
Lantânio/química , Óxidos/química , Fosfolipídeos/análise , Fosfopeptídeos/análise , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Proteínas do Ovo/análise , Gema de Ovo/metabolismo , Compostos de Epóxi/química , Humanos , Limite de Detecção , Fosfolipídeos/sangue , Fosfolipídeos/isolamento & purificação , Fosfopeptídeos/sangue , Fosfopeptídeos/isolamento & purificação , Fosvitina/análise , Polímeros/química , Porosidade , Extração em Fase Sólida , Compostos de Vinila/química
14.
Psychopathology ; 50(6): 379-388, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29017153

RESUMO

The psychopathological condition of Robert Schumann has been a prominent object of study in psychiatry since his hospitalization in 1854. Renowned psychiatrists have diagnosed Schumann with syphilis, schizophrenia, and bipolar and personality disorders. Until today, these analyses of his symptomatology have led to contradictory results. Recent discussion has suggested that his hospitalization was due to professional failure and separation wishes on the part of his wife, her family, and her friends. In line with this hypothesis is the opinion that the separation insisted upon by Clara Schumann was reinforced by the economic interests of the psychiatrist who kept Schumann in custody for 2 years until his death in 1856. In this article, we trace the complex interaction of bipolar vulnerability and pathogenic life events with hypersensitive talent and "creative bipolarity," defined as the capacity, motivation, and resilience to transform emotional stress and cognitive inconsistency into coherent artistic products. Finally, we present our conclusions about comprehensive psychiatric and psychotherapeutic treatment with respect to "creative bipolarity."


Assuntos
Transtorno Bipolar/psicologia , Psicopatologia/métodos , Criatividade , História Antiga , Humanos , Masculino
15.
J Sep Sci ; 39(21): 4175-4182, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27592854

RESUMO

Selectivity and sensitivity define the dynamic applicability of separation and enrichment techniques. Owing to proteome complexity, numbers of separation media have been introduced in phosphoproteomics. Complex samples are pretreated to make the low-abundance molecules detectable by mass spectrometry. Gadolinium oxide nanoparticles, offering mono- and bi-dentate interactions, are optimized to capture the phosphopeptides. Selectivity of 1:11 000 is achieved for digested ß-casein phosphopeptides in bovine serum albumin digest background using gadolinium oxide nanoparticles. The limit of detection goes down to 1 attomole. With the optimized sample preparation protocol, gadolinium oxide nanoparticles enrich phosphopeptides of κ-casein (Ser148 and Ser170 ) from digested milk sample, fibrinogen alpha chain phosphopeptide (Ser609 ) along with four hydrolytic products of Ser22 -modified phosphopeptides from serum.


Assuntos
Caseínas/isolamento & purificação , Gadolínio/química , Nanopartículas/química , Fosfopeptídeos/isolamento & purificação , Animais , Leite , Soro , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
16.
Anal Chem ; 87(9): 4726-32, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25859614

RESUMO

Metal oxides show high selectivity and sensitivity toward mass spectrometry based enrichment strategies. Phosphopeptides/phosphoproteins enrichment from biological samples is cumbersome because of their low abundance. Phosphopeptides are of interest in enzymes and phosphorylation pathways which lead to the clinical links of a disease. Magnetic core-shell lanthanide oxide nanoparticles (Fe3O4@SiO2-La2O3 and Fe3O4@SiO2-Sm2O3) are fabricated, characterized by SEM, FTIR, and EDX and employed in the enrichment of phosphopeptides. The nanoparticles enrich phosphopeptides from casein variants, nonfat milk, egg yolk, human serum and HeLa cell extract. The materials and enrichment protocols are designed in a way that there are almost no nonspecific bindings. The selectivity is achieved up to 1:8500 using ß-casein/BSA mixture and sensitivity down to 1 atto-mole. Batch-to-batch reproducibility is high with the reuse of core-shell nanoparticles up to four cycles. The enrichment followed by MALDI-MS analyses is carried out for the identification of phosphopeptides from serum digest and HeLa cell extract. Characteristic phosphopeptides of phosphoproteins are identified from human serum after the enrichment, which have the diagnostic potential toward prostate cancer. Thus, the lanthanide based magnetic core-shell materials offer a highly selective and sensitive workflow in phosphoproteomics.


Assuntos
Elementos da Série dos Lantanídeos/química , Imãs/química , Nanopartículas/química , Óxidos/química , Fosfoproteínas/análise , Proteoma/análise , Proteômica , Animais , Gema de Ovo/química , Células HeLa , Humanos , Fenômenos Magnéticos , Leite/química , Estrutura Molecular , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
17.
J Sep Sci ; 38(8): 1334-43, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25645427

RESUMO

In this study, a novel method for the highly selective enrichment of phosphopeptides using erbium phosphate doped poly(glycidyl methacrylate/ethylene dimethacrylate) spin columns is presented. Erbium phosphate was synthesized by precipitation from boiling phosphoric acid and incubated overnight in erbium chloride solutions. The resulting powder was embedded in a monolithic poly(glycidyl methacrylate/ethylene dimethacrylate) polymer. The monolith was synthesized in a spin column by radical polymerization. Erbium phosphate demonstrated a high affinity and selectivity for phosphopeptides due to the strong interaction of trivalent erbium ions with the phosphate groups of phosphopeptides. The high selectivity and performance of the designed spin columns were demonstrated by successfully enriching phosphopeptides from tryptically digested protein mixtures containing the model phosphoproteins α- and ß-casein, bovine milk, and human saliva. By the implementation of several washing steps, unspecific components were removed and the enriched phosphopeptides were effectively eluted from the spin columns under alkaline conditions. The selective performance of the presented method was further demonstrated by the enrichment of two synthetic phosphopeptides, which were spiked in tryptically digested and dephosphorylated HeLa cell lysates at low ratios. Finally, the presented approach was compared to conventional phosphopeptide enrichment by titanium oxide and revealed higher recoveries for the erbium phosphate doped monoliths.


Assuntos
Érbio/química , Metacrilatos/química , Fosfatos/química , Fosfopeptídeos/química , Ácidos Polimetacrílicos/química , Sequência de Aminoácidos , Animais , Caseínas/química , Bovinos , Células HeLa , Humanos , Íons , Microscopia Eletrônica de Varredura , Leite/química , Dados de Sequência Molecular , Fosfoproteínas/química , Polímeros/química , Saliva/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem , Tripsina/química
18.
J Sep Sci ; 37(16): 2200-7, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24913248

RESUMO

Thionins belong to a family of cysteine-rich, low-molecular-weight (∼5 KDa) biologically active proteins in the plant kingdom. They display a broad cellular toxicity against a wide range of organisms and eukaryotic cell lines. Thionins protect plants against different pathogens, including bacteria and fungi. A highly selective solid-phase extraction method for plant thionins is reported deploying aluminum silicate (3:2 mullite) powder as a sorbent in extraction columns. Mullite was shown to considerably improve selectivity compared to a previously described zirconium silicate embedded poly(styrene-co-divinylbenzene) monolithic polymer. Due to the presence of aluminum(III), mullite offers electrostatic interactions for the selective isolation of cysteine-rich proteins. In comparison to zirconium(IV) silicate, aluminum(III) silicate showed reduced interactions towards proteins which resulted into superior washings of unspecific compounds while still retaining cysteine-rich thionins. In the presented study, European mistletoe, wheat and barley samples were subjected to solid-phase extraction analysis for isolation of viscotoxins, purothionins and hordothionins, respectively. Matrix-assisted laser desorption/ionization time of flight mass spectroscopy was used for determining the selectivity of the sorbent toward thionins. The selectively retained thionins were quantified by colorimetric detection using the bicinchoninic acid assay. For peptide mass-fingerprint analysis tryptic digests of eluates were examined.


Assuntos
Silicatos de Alumínio/análise , Extratos Vegetais/química , Extração em Fase Sólida , Tioninas/análise , Peptídeos Catiônicos Antimicrobianos/química , Colorimetria , Hordeum/química , Microscopia Eletrônica de Varredura , Erva-de-Passarinho/química , Proteínas de Plantas/química , Polímeros/química , Silicatos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Tioninas/química , Triticum/química , Zircônio/química
19.
Biomed Chromatogr ; 28(3): 412-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24097333

RESUMO

In this study a new type of immobilized metal ion affinity chromatography resin for the enrichment of carbohydrates and polyols was synthesized by radical polymerization reaction of vinyl phosphonic acid and 1,4-butandiole dimethacrylate using azo-bis-isobutyronitrile as radical initiator. Interaction between the chelated trivalent lanthanide ions and negatively charged hydroxyl groups of carbohydrates and polyols was observed by applying high pH values. The new method was evaluated by single standard solutions, mixtures of standards, honey and a more complex extract of Cynara scolymus. The washing step was accomplished by acetonitrile in excess volumes. Elution of enriched carbohydrates was successfully performed with deionized water. The subsequent analysis was carried out with matrix-free laser desorption/ionization-time of flight mass spectrometry involving a TiO2 -coated steel target, especially suitable for the measurement of low-molecular-weight substances. Quantitative analysis of the sugar alcohol xylitol as well as the determination of the maximal loading capacity was performed by gas chromatography in conjunction with mass spectrometric detection after chemical derivatization. In a parallel approach quantum mechanical geometry optimizations were performed in order to compare the coordination behavior of various trivalent lanthanide ions.


Assuntos
Carboidratos/isolamento & purificação , Cromatografia de Afinidade/métodos , Elementos da Série dos Lantanídeos/química , Polímeros/isolamento & purificação , Carboidratos/análise , Cynara scolymus/química , Cromatografia Gasosa-Espectrometria de Massas , Mel/análise , Limite de Detecção , Extratos Vegetais/química , Polímeros/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 310: 123955, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38306925

RESUMO

This comprehensive review paper aims to captivate the applicability of in-sorbent detection, where near-infrared spectroscopy (NIRS) converges with enrichment technologies. For this purpose, we collected and summarized information regarding the combination of several sophisticated analytical enrichment techniques with NIRS to further explore and develop this synergistic approach. Peer-reviewed publications, matching the criteria of in situ NIR measurements prior analyte elution, have been collected, investigated, and concluded within this review. Investigations according to used materials, commercial or self-made, composition, organic or inorganic and applied analytical methodologies have been carried out. Applications extending over a multitude of chemical fields, from environmental to medicinal applications. As this review concludes, the combination of these techniques further expands the applicability of NIRS and moreover tries to solve the long-standing issue of the comparably low sensitivity regarding this vibrational technique.

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