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Avaliação do perfil urinário de biomarcadores do stress oxidativo e a sua correlação com as doenças cardiovasculares

Mendes, Berta Rodrigues
Fonte: Universidade da Madeira Publicador: Universidade da Madeira
Tipo: Dissertação de Mestrado
Publicado em //2012 POR
Relevância na Pesquisa
16.38%
Com a realização deste trabalho pretendeu-se estabelecer o perfil urinário de níveis de biomarcadores do stress oxidativo (5-HMU; UAc; MDA; 8-OHdG) em indivíduos saudáveis (grupo controlo) comparando com o de doenças cardiovasculares (grupo CVD) de modo a avaliar o seu potencial como possíveis biomarcadores da possibilidade de ocorrência de CVD. A extração dos compostos alvos foi realizada por recurso a uma nova técnica extrativa - microextração com adsorvente empacotado em seringa (MEPS) controlada digitalmente (eVol). A análise dos biomarcadores foi efetuada por cromatografia líquida de ultra eficiência (UHPLC) utilizando como coluna analítica a HSS T3 (100 mm × 2,1 mm, 1,7 μm de tamanho da partícula) e com um sistema deteção de fotodiodos (PDA). Otimizaram-se os parâmetros experimentais com influência no processo extrativo, nomeadamente no que se refere ao tipo de adsorvente, á influência do pH, ao volume de amostra, ao número de ciclos extrativos, lavagem e ao volume de eluição. Foram ensaiadas diferentes condições experimentais e selecionadas as que corresponderam a uma maior eficiência extrativa, expressa pela área total relativa dos analitos e reprodutibilidade. Os melhores resultados foram obtidos usando como adsorvente C8...

High resolution ultra high pressure liquid chromatography-time-of-flight mass spectrometry dereplication strategy for the metabolite profiling of Brazilian Lippia species

Funari, Cristiano S.; Eugster, Philippe J.; Martel, Sophie; Carrupt, Pierre-Alain; Wolfender, Jean-Luc; Silva, Dulce Helena S.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 167-178
ENG
Relevância na Pesquisa
36.82%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Plants belonging to the Lippia genus have been widely used in ethnobotany throughout South and Central America and in tropical Africa as foods, medicines, sweeteners and in beverage flavouring. Various taxonomic problems involving some genera from Verbenaceae, including Lippia. have been reported. In this study, the metabolite profiling of fifteen extracts of various organs of six Lippia species was performed and compared using UHPLC-PDA-TOF-MS. Fourteen phenolic compounds that were previously isolated from L salviaefolia Cham. and L lupulina Cham. were used as references. The annotation of the remaining LC peaks was based on concomitant online high mass accuracy measurements and subsequent molecular formula assignments following these different steps: (i) elimination of non-coherent putative molecular formulae by heuristic filtering, (ii) verification of the occurrence of remaining molecular formulae in databases. (iii) cross search with reported compounds in the Lippia genus, (iv) match with reported UV spectra, (v) estimation of the chromatographic retention behaviour based on the log P parameter of reference compounds. This strategy is generic and time-saving...

UHPLC-PDA-ESI/HRMS/MSn Analysis of Anthocyanins, Flavonol Glycosides, and Hydroxycinnamic Acid Derivatives in Red Mustard Greens (Brassica juncea Coss Variety)

Lin, Long-Ze; Sun, Jianghao; Chen, Pei; Harnly, James
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
47.17%
An UHPLC-PDA-ESI/HRMS/MSn profiling method was used for a comprehensive study of the phenolic components of red mustard greens (Brassica juncea Coss variety) and identified 67 anthocyanins, 102 flavonol glycosides, and 40 hydroxycinnamic acid derivatives. The glycosylation patterns of the flavonoids were assigned on the basis of direct comparison of the parent flavonoid glycosides with reference compounds. The putative identifications were obtained from tandem mass data analysis and confirmed by the retention time, elution order, and UV–vis and high-resolution mass spectra. Further identifications were made by comparing the UHPLC-PDA-ESI/HRMS/MSn data with those of reference compounds in the polyphenol database and in the literature. Twenty-seven acylated cyanidin 3-sophoroside-5-diglucosides, 24 acylated cyanidin 3-sophoroside-5- glucosides, 3 acylated cyanidin triglucoside-5-glucosides, 37 flavonol glycosides, and 10 hydroxycinnamic acid derivatives were detected for the first time in brassica vegetables. At least 50 of them are reported for the first time in any plant materials.

Profiling Polyphenols in Five Brassica species Microgreens by UHPLC-PDA-ESI/HRMSn

Sun, Jianghao; Xiao, Zhenlei; Lin, Long-ze; Lester, Gene E.; Wang, Qin; Harnly, James M.; Chen, Pei
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
47.05%
Brassica vegetables are known to contain relatively high concentrations of bioactive compounds associated with human health. A comprehensive profiling of polyphenols from five Brassica species microgreens was conducted using ultra high-performance liquid chromatography photo diode array high-resolution multi-stage mass spectrometry (UHPLC-PDA-ESI/HRMSn). A total of 164 polyphenols including 30 anthocyanins, 105 flavonol glycosides, and 29 hydroxycinnamic acid and hydroxybenzoic acid derivatives were putatively identified.The putative identifications were based on UHPLC-HRMSn analysis using retention times, elution orders, UV/Vis spectra and high resolution mass spectra, in-house polyphenol database, and as well as literature comparisons. This study showed that these five Brassica species microgreens could be considered as good sources of food polyphenols.

Profiling of Glucosinolates and Flavonoids in Rorippa indica (Linn.) Hiern. (Cruciferae) by UHPLC-PDA-ESI/HRMSn

Lin, Long-Ze; Sun, Jianghao; Chen, Pei; Zhang, Ren-Wei; Fan, Xiao-E; Li, Lai-Wei; Harnly, James M.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.38%

UHPLC-PDA-ESI/HRMSn Profiling Method To Identify and Quantify Oligomeric Proanthocyanidins in Plant Products

Lin, Long-Ze; Sun, Jianghao; Chen, Pei; Monagas, Maria J.; Harnly, James M.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.38%

Desenvolvimento e validação de novas metodologias anlíticas baseadas na MEPS/UHPLC-PDA para a determinação de antidepressivos em amostras de urina

Alves, Vera Lúcia Gouveia
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Dissertação de Mestrado
POR
Relevância na Pesquisa
47.45%
A descoberta dos medicamentos antidepressivos no final dos anos 50, tornou a depressão um problema médico passível de tratamento. Assim sendo, nas últimas décadas, a psicofarmacologia da depressão evoluiu muito rapidamente, surgindo novos fármacos antidepressivos, retratando-se num aumento de 240% no consumo destes. Contudo, apesar da eficácia antidepressiva e da semelhante gama de indicações, cada antidepressivo possui propriedades individuais, não só farmacodinâmicas como também farmacocinéticas, resultando num perfil de indicações clínicas diferente, assim como efeitos adversos e inclusivamente interações medicamentosas. Além disso, a sua possível aquisição de forma ilegal, contribui para os problemas de automedicação e aumento do risco de suicídio por parte dos indivíduos. Assim sendo, e face aos efeitos colaterais causados por estes medicamentos, torna-se crucial o desenvolvimento de metodologias analíticas que possibilitem a identificação e quantificação destes fármacos em matrizes biológicas de uma forma rápida, simples e económica. Neste sentido, surge o presente estudo cujo objetivo prende-se com a determinação de dois antidepressivos de classes diferentes, nomeadamente a fluoxetina, a clomipramina e os respetivos metabolitos ativos norfluoxetina e desmetilclomipramina...

Quantificação de antipsicóticos em urina recorrendo à microextração por sorvente empacotado combinada com a cromatografia líquida de ultra eficiência

Gonçalves, João Luís Jesus
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Dissertação de Mestrado
POR
Relevância na Pesquisa
27.15%
Desde a sua introdução, na década de 50, que os antipsicóticos se tornaram amplamente prescritos na psiquiatria clínica, como tratamento de primeira linha para a esquizofrenia e outros distúrbios psicóticos. Com o atual crescimento do consumo de antipsicóticos em Portugal, e face aos efeitos colaterais causados por estes, tornou-se indispensável o desenvolvimento de metodologias analíticas que possibilitassem a identificação e quantificação destes fármacos em matrizes biológicas de forma rápida, simples e económica. Neste sentido, surge o nosso presente estudo, cujo principal objetivo foi a determinação de antipsicóticos, nomeadamente a clozapina, a risperidona e os seus metabolitos ativos norclozapina e 9-hidroxiriperidona, em amostras de urina, recorrendo à microextração por sorvente empacotado (MEPS), seguido de análise por cromatografia líquida de ultra eficiência com detetor de fotodiodos (UHPLC-PDA). Foram alvo de avaliação neste trabalho os fatores que influenciam o desempenho da MEPS, incluindo o tipo de sorvente, o número de ciclos de extração, o volume de amostra, o pH da amostra, o sistema de solventes e o volume de eluição. As melhores condições de extração envolveram a passagem de 500 μL de amostra através do sorvente C18 em 5 ciclos de extração. O extrato obtido foi analisado por UHPLC...

Development of a novel microextraction by packed sorbent-based approach followed by ultrahigh pressure liquid chromatography as a powerful technique for quantification phenolic constituents of biological interest in wines

Gonçalves, João; Mendes, Berta; Silva, Catarina L.; Câmara, José S.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /03/2012 ENG
Relevância na Pesquisa
37.27%
A novel analytical approach, based on a miniaturized extraction technique, the microextraction by packed sorbent (MEPS), followed by ultrahigh pressure liquid chromatography (UHPLC) separation combined with a photodiode array (PDA) detection, has been developed and validated for the quantitative determination of sixteen biologically active phenolic constituents of wine. In addition to performing routine experiments to establish the validity of the assay to internationally accepted criteria (linearity, sensitivity, selectivity, precision, accuracy), experiments are included to assess the effect of the important experimental parameters on the MEPS performance such as the type of sorbent material (C2, C8, C18, SIL, and M1), number of extraction cycles (extract-discard), elution volume, sample volume, and ethanol content, were studied. The optimal conditions of MEPS extraction were obtained using C8 sorbent and small sample volumes (250 μL) in five extraction cycle and in a short time period (about 5 min for the entire sample preparation step). The wine bioactive phenolics were eluted by 250 μL of the mixture containing 95% methanol and 5% water, and the separation was carried out on a HSS T3 analytical column (100 mm × 2.1 mm, 1.8 μm particle size) using a binary mobile phase composed of aqueous 0.1% formic acid (eluent A) and methanol (eluent B) in the gradient elution mode (10 min of total analysis). The method gave satisfactory results in terms of linearity with r2-values > 0.9986 within the established concentration range. The LOD varied from 85 ng mL−1 (ferulic acid) to 0.32 μg mL−1 ((+)-catechin)...

A new and improved strategy combining a dispersive-solid phase extraction-based multiclass method with ultra high pressure liquid chromatography for analysis of low molecular weight polyphenols in vegetables

Silva, Catarina L.; Haesen, Nathaly; Câmara, José S.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /10/2012 ENG
Relevância na Pesquisa
36.9%
This paper reports on the development and optimization of a modified Quick, Easy, Cheap Effective, Rugged and Safe (QuEChERS) based extraction technique coupled with a clean-up dispersive-solid phase extraction (dSPE) as a new, reliable and powerful strategy to enhance the extraction efficiency of free low molecular-weight polyphenols in selected species of dietary vegetables. The process involves two simple steps. First, the homogenized samples are extracted and partitioned using an organic solvent and salt solution. Then, the supernatant is further extracted and cleaned using a dSPE technique. Final clear extracts of vegetables were concentrated under vacuum to near dryness and taken up into initial mobile phase (0.1% formic acid and 20% methanol). The separation and quantification of free low molecular weight polyphenols from the vegetable extracts was achieved by ultrahigh pressure liquid chromatography (UHPLC) equipped with a phodiode array (PDA) detection system and a Trifunctional High Strength Silica capillary analytical column (HSS T3), specially designed for polar compounds. The performance of the method was assessed by studying the selectivity, linear dynamic range, the limit of detection (LOD) and limit of quantification (LOQ)...

An improved and fast UHPLC-PDA methodology for determination of L-ascorbic and dehydroascorbic acids in fruits and vegetables: evaluation of degradation rate during storage

Spínola, Vítor; Mendes, Berta; Câmara, José S.; Castilho, Paula C.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Publicado em /01/2012 ENG
Relevância na Pesquisa
47.17%
This study provides a versatile validated method to determine the total vitamin C content, as the sum of the contents of L-ascorbic acid (L-AA) and dehydroascorbic acid (DHAA), in several fruits and vegetables and its degradability with storage time. Seven horticultural crops from two different origins were analyzed using an ultrahigh-performance liquid chromatographic–photodiode array (UHPLC-PDA) system, equipped with a new trifunctional high strength silica (100% silica particle) analytical column (100 mm×2.1 mm, 1.7 μm particle size) using 0.1% (v/v) formic acid as mobile phase, in isocratic mode. This new stationary phase, specially designed for polar compounds, overcomes the problems normally encountered in HPLC and is suitable for the analysis of large batches of samples without L-AA degradation. In addition, it proves to be an excellent alternative to conventional C18 columns for the determination of L-AA in fruits and vegetables. The method was fully validated in terms of linearity, detection (LOD) and quantification (LOQ) limits, accuracy, and inter/intraday precision. Validation experiments revealed very good recovery rate of 96.6±4.4% for L-AA and 103.1±4.8 % for total vitamin C, good linearity with r2-values >0.999 within the established concentration range...

A fast method using a new hydrophilic–lipophilic balanced sorbent in combination with ultra-high performance liquid chromatography for quantification of significant bioactive metabolites in wines

Silva, Catarina L.; Pereira, Jorge; Wouter, Van G.; Giró, Carme; Câmara, José S.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /10/2011 ENG
Relevância na Pesquisa
27.05%
This manuscript describes the development and validation of an ultra-fast, efficient, and high throughput analytical method based on ultra-high performance liquid chromatography (UHPLC) equipped with a photodiode array (PDA) detection system, for the simultaneous analysis of fifteen bioactive metabolites: gallic acid, protocatechuic acid, (−)-catechin, gentisic acid, (−)-epicatechin, syringic acid, p-coumaric acid, ferulic acid, m-coumaric acid, rutin, trans-resveratrol, myricetin, quercetin, cinnamic acid and kaempferol, in wines. A 50-mm column packed with 1.7-μm particles operating at elevated pressure (UHPLC strategy) was selected to attain ultra-fast analysis and highly efficient separations. In order to reduce the complexity of wine extract and improve the recovery efficiency, a reverse-phase solid-phase extraction (SPE) procedure using as sorbent a new macroporous copolymer made from a balanced ratio of two monomers, the lipophilic divinylbenzene and the hydrophilic N-vinylpyrrolidone (Oasis™ HLB), was performed prior to UHPLC–PDA analysis. The calibration curves of bioactive metabolites showed good linearity within the established range. Limits of detection (LOD) and quantification (LOQ) ranged from 0.006 μg mL−1 to 0.58 μg mL−1...