Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
Reprod Fertil Dev ; 29(6): 1217-1230, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27220988

RESUMO

Dietary rumen-protected polyunsaturated fatty acids (PUFAs) rich in linoleic acid (LA) may affect embryo yield, and LA can modulate the molecular mechanisms of lipid uptake in bovine blastocysts produced in vitro. In embryos, membrane lipids, such as phosphatidylcholines (PCs) and sphingomyelins (SMs), affect cryopreservation success. The aim of the present study was to evaluate embryonic developmental rates after the IVF of oocytes retrieved from Nellore heifers fed for approximately 90 days with rumen-protected PUFAs rich in LA. In addition, we evaluated embryo cryotolerance and the membrane structure lipid composition using matrix-assisted laser desorption ionisation mass spectrometry of fresh and vitrified embryos. Embryo development to the blastocyst stage (mean 43.2%) and embryo survival after vitrification and warming (mean 79.3%) were unaffected by diet. The relative abundance of one lipid species (PC ether (PCe; 38:2, which means that this lipid has 38 carbon atoms and 2 double bonds in the fatty acyl residues) was increased after PUFAs supplementation. However, 10 ions were affected by cryopreservation; ions consistent with PC 32:0, PC 34:1, SM 24:1, PC 40:6 or PC 42:9, PC plasmalogen (PCp) 44:10 or PC 42:7, triacylglycerol (TAG) 54:9 and a not assigned ion (m/z 833.2) were lower in blastocysts that survived to the cryopreservation process compared with fresh blastocysts, whereas the abundance of the ions PC 36:3 or PC 34:0, PCe 38:2 or PC 36:6 and PC 36:5 or PCe 38:1 were increased after cryopreservation. Thus, the results demonstrate that the mass spectrometry profiles of PC, SM and TAG species differ significantly in bovine blastocysts upon cryopreservation. Because the lipid ion abundances of fresh and vitrified-warmed embryos were distinct, they can be used as potential markers of post-cryopreservation embryonic survival.


Assuntos
Criopreservação/veterinária , Gorduras Insaturadas na Dieta/administração & dosagem , Ectogênese , Embrião de Mamíferos/metabolismo , Fenômenos Fisiológicos da Nutrição Materna , Lipídeos de Membrana/metabolismo , Oocistos/metabolismo , Animais , Animais Endogâmicos , Blastocisto , Brasil , Bovinos , Estudos Cross-Over , Embrião de Mamíferos/citologia , Feminino , Fertilização in vitro/veterinária , Técnicas de Maturação in Vitro de Oócitos/veterinária , Ácido Linoleico/administração & dosagem , Ácido Linoleico/metabolismo , Masculino , Lipídeos de Membrana/química , Oocistos/citologia , Oocistos/isolamento & purificação , Recuperação de Oócitos/veterinária , Plasmalogênios/química , Plasmalogênios/metabolismo , Preservação do Sêmen/veterinária , Vitrificação
2.
Rapid Commun Mass Spectrom ; 29(16): 1530-4, 2015 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-26212168

RESUMO

RATIONALE: Citrus aurantium L. is a plant belonging to the Rutaceae family, whose extracts are extensively used in weight management products and as thermogenic agents. Here we present two methodologies to analyse the extracts obtained from the peels of Citrus aurantium L. that usually require multiple sample preparation and detection steps. METHODS: Polar compounds of the crude extract from the peels of Citrus aurantium L. (Rutaceae) were investigated by direct infusion electrospray ionization mass spectrometry (ESI-MS) and high-performance thin-layer chromatography (HPTLC) coupled to desorption electrospray ionization mass spectrometry (DESI-MS). ESI-MS was performed in both positive and negative ion modes. Molecular imaging of the HPTLC plates was used for the direct analysis of the phytocompounds present in the crude extract from the peels of Citrus aurantium L. by DESI-MS imaging. RESULTS: Characteristic mass spectra with many diagnostic ions were obtained from the extract analysis, allowing a fast and reliable identification of these species. Tandem mass spectrometry (MS/MS) was employed to confirm the identity of specific metabolites. CONCLUSIONS: HPTLC/DESI-MS imaging is a relatively fast, versatile, and efficient technique for natural product analysis, since many more ions are observed than with the direct infusion ESI-MS. The MS/MS technique provided information about the component structures, revealing the presence of important bioactive components. The application of DESI-MS imaging may contribute to the improvement identification and characterization of pharmacologically active compounds in phytochemistry.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Citrus/química , Frutas/química , Compostos Fitoquímicos/análise , Extratos Vegetais/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Compostos Fitoquímicos/química
3.
Zygote ; 23(5): 732-41, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25213102

RESUMO

This study aimed to evaluate the impact of vitrification on membrane lipid profile obtained by mass spectrometry (MS) of in vitro-produced bovine embryos. Matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) has been used to obtain individual embryo membrane lipid profiles. Due to conditions of analysis, mainly membrane lipids, most favorably phosphatidylcholines (PCs) and sphingomyelins (SMs) have been detected. The following ions described by their mass-to-charge ratio (m/z) and respective attribution presented increased relative abundance (1.2-20×) in the vitrified group: 703.5 [SM (16:0) + H]+; 722.5 [PC (40:3) + Na]+; 758.5 [PC (34:2) + H]+; 762.5 [PC (34:0) + H]+; 790.5 [PC (36:0) + H]+ and 810.5 [PC (38:4) + H]+ and/or [PC (36:1) + Na]+. The ion with a m/z 744.5 [PCp (34:1) and/or PCe (34:2)] was 3.4-fold more abundant in the fresh group. Interestingly, ions with m/z 722.5 or 744.5 indicate the presence of lipid species, which are more resistant to enzymatic degradation as they contain fatty acyl residues linked through ether type bonds (alkyl ether or plasmalogens, indicated by the lowercase 'e' and 'p', respectively) to the glycerol structure. The results indicate that cryopreservation impacts the membrane lipid profile, and that these alterations can be properly monitored by MALDI-MS. Membrane lipids can therefore be evaluated by MALDI-MS to monitor the effect of cryopreservation on membrane lipids, and to investigate changes in lipid profile that may reflect the metabolic response to the cryopreservation stress or changes in the environmental conditions.


Assuntos
Biomarcadores/análise , Embrião de Mamíferos/metabolismo , Fertilização in vitro/veterinária , Técnicas de Maturação in Vitro de Oócitos/veterinária , Lipídeos de Membrana/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/veterinária , Vitrificação , Animais , Bovinos , Embrião de Mamíferos/citologia , Feminino
4.
Malar J ; 10: 112, 2011 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-21535894

RESUMO

BACKGROUND: To overcome the problem of increasing drug resistance, traditional medicines are an important source for potential new anti-malarials. Caesalpinia pluviosa, commonly named "sibipiruna", originates from Brazil and possess multiple therapeutic properties, including anti-malarial activity. METHODS: Crude extract (CE) was obtained from stem bark by purification using different solvents, resulting in seven fractions. An MTT assay was performed to evaluate cytotoxicity in MCF-7 cells. The CE and its fractions were tested in vitro against chloroquine-sensitive (3D7) and -resistant (S20) strains of Plasmodium falciparum and in vivo in Plasmodium chabaudi-infected mice. In vitro interaction with artesunate and the active C. pluviosa fractions was assessed, and mass spectrometry analyses were conducted. RESULTS: At non-toxic concentrations, the 100% ethanolic (F4) and 50% methanolic (F5) fractions possessed significant anti-malarial activity against both 3D7 and S20 strains. Drug interaction assays with artesunate showed a synergistic interaction with the F4. Four days of treatment with this fraction significantly inhibited parasitaemia in mice in a dose-dependent manner. Mass spectrometry analyses revealed the presence of an ion corresponding to m/z 303.0450, suggesting the presence of quercetin. However, a second set of analyses, with a quercetin standard, showed distinct ions of m/z 137 and 153. CONCLUSIONS: The findings show that the F4 fraction of C. pluviosa exhibits anti-malarial activity in vitro at non-toxic concentrations, which was potentiated in the presence of artesunate. Moreover, this anti-malarial activity was also sustained in vivo after treatment of infected mice. Finally, mass spectrometry analyses suggest that a new compound, most likely an isomer of quercetin, is responsible for the anti-malarial activity of the F4.


Assuntos
Antimaláricos/administração & dosagem , Antimaláricos/farmacologia , Caesalpinia/química , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacologia , Animais , Antimaláricos/isolamento & purificação , Antimaláricos/toxicidade , Artemisininas/farmacologia , Artesunato , Brasil , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Sinergismo Farmacológico , Humanos , Malária/tratamento farmacológico , Malária/parasitologia , Camundongos , Camundongos Endogâmicos C57BL , Casca de Planta/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Plantas Medicinais/química , Plasmodium chabaudi/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Quercetina/administração & dosagem , Quercetina/isolamento & purificação , Quercetina/farmacologia , Quercetina/toxicidade , Doenças dos Roedores/tratamento farmacológico , Doenças dos Roedores/parasitologia
5.
Analyst ; 135(4): 738-44, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20349539

RESUMO

A fast and reliable method is presented for the analysis of vegetable oils. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) is shown to efficiently desorb and ionize the main oil constituents from an inert surface under ambient conditions and to provide comprehensive triacylglyceride (TAG) and free fatty acid (FFA) profiles detected mainly as either [TAG + Na](+) or [FFA-H](-) ions. EASI(+/-)-MS analysis is simple, easily implemented, requires just a tiny droplet of the oil and is performed without any pre-separation or chemical manipulation. It also causes no fragmentation of TAG ions hence diacylglyceride (DAG) and monoacylglyceride (MAG) profiles and contents can also be measured. The EASI(+/-)-MS profiles of TAG and FFA permit authentication and quality control and can be used, for instance, to access levels of adulteration, acidity, oxidation or hydrolysis of vegetable oils in general.


Assuntos
Ácidos Graxos/química , Óleos de Plantas/química , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Triglicerídeos/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Ultrassom
6.
J Nat Prod ; 73(6): 1180-3, 2010 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-20476748

RESUMO

Phytochemical investigation of the bark of Guatteria hispida afforded three new alkaloids, 9-methoxy-O-methylmoschatoline (1), 9-methoxyisomoschatoline (2), and isocerasonine (3), along with 10 known alkaloids, 8-oxopseudopalmatine (4), O-methylmoschatoline (5), lysicamine (6), liriodenine (7), 10-methoxyliriodenine (8), nornuciferine (9), anonaine (10), xylopine (11), coreximine (12), and isocoreximine (13). The major compounds, 2, 6, 12, and 13, showed significant antioxidant capacity in the ORAC(FL) assay. Compounds 5, 6, and 7 were active against S. epidermidis and C. dubliniensis, with MIC values in the range 12.5-100 microg mL(-1).


Assuntos
Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Guatteria/química , Plantas Medicinais/química , Alcaloides/química , Antibacterianos/química , Antifúngicos/química , Antioxidantes/química , Aporfinas/química , Brasil , Candida/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Casca de Planta/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus/efeitos dos fármacos
7.
J Nat Prod ; 72(8): 1529-32, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19658431

RESUMO

Two new lignans, magnovatins A (1) and B (2), along with nine known compounds, were isolated from the leaves of Magnolia ovata. The known compounds were identified as acuminatin (3), licarin A (4), kadsurenin M, 4-O-demethylkadsurenin M, oleiferin A, oleiferin C, spathulenol, parthenolide, and 11,13-dehydrocompressanolide. In addition, compounds 1 and 2 yielded four new derivatives (1a, 1b, 2a, and 2b). The structures of the new compounds were established on the basis of spectrometric data evaluation. Free-radical scavenging and antimicrobial activities of the major compunds 1, 3, and 4 were investigated.


Assuntos
Antibacterianos/isolamento & purificação , Sequestradores de Radicais Livres/isolamento & purificação , Magnolia/química , Plantas Medicinais/química , Antibacterianos/química , Antibacterianos/farmacologia , Brasil , Escherichia coli/efeitos dos fármacos , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Lignanas/isolamento & purificação , Lignanas/farmacologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus epidermidis/efeitos dos fármacos , Leveduras/efeitos dos fármacos
8.
Methods Mol Biol ; 1203: 63-77, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25361667

RESUMO

Desorption electrospray ionization (DESI) allows the direct analysis of ordinary objects or preprocessed samples under ambient conditions. Among other applications, DESI is used to identify and to record spatial distributions of small molecules in situ, sliced or imprinted biological tissue. Manipulation of the chemistry accompanying ambient analysis ionization can be used to optimize chemical analysis, including molecular imprinting. Images are obtained by continuously moving the sample relative to the DESI sprayer and the inlet of the mass spectrometer. The acquisition time depends on the size of the surface to be analyzed and on the desired resolution.


Assuntos
Imagem Molecular/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Métodos Analíticos de Preparação de Amostras , Animais , Fragaria/citologia , Fragaria/metabolismo , Frutas/citologia , Frutas/metabolismo , Ginkgo biloba/citologia , Ginkgo biloba/metabolismo , Folhas de Planta/citologia , Folhas de Planta/metabolismo , Solventes/química , Temperatura , Peixe-Zebra/metabolismo
9.
J Am Soc Mass Spectrom ; 24(6): 956-65, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23605686

RESUMO

Imprints of potato sprout (Solanum tuberosum L.), gingko leaves (Gingko biloba L.) and strawberries (Fragaria x ananassa Duch.) were successfully imaged by desorption electrospray ionization mass spectrometry (DESI-MS) on TLC plates through blotting assisted by heating and/or solvent extraction. Ion images showing the distribution of significant compounds such as glycoalkaloid toxins in potato sprout, ginkgolic acids and flavonoids in ginkgo leaves, and sugars and anthocyanidin in strawberry were obtained. Practical implications of this work include analysis of a wide range of irregular or soft materials by different imprinting conditions without requiring the addition of matrices or use of specific kinds of surfaces.


Assuntos
Imagem Molecular/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Acetonitrilas/química , Alcaloides/análise , Alcaloides/química , Carboidratos/análise , Carboidratos/química , Flavonoides/análise , Flavonoides/química , Fragaria/química , Ginkgo biloba/química , Temperatura Alta , Metanol/química , Folhas de Planta/química , Salicilatos/análise , Salicilatos/química , Solanum tuberosum/química , Solventes/química
10.
J Mass Spectrom ; 48(7): 774-8, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23832933

RESUMO

Desorption electrospray ionization mass spectrometry (DESI-MS) is employed in the forensic analysis of chemical components present in condoms and imaging of latent fingerprints as circumstantial evidence of sexual assault. Polymers such as nonoxynol-9, polyethylene glycol, and polydimethylsiloxane, as well as small molecules additives such as N-methylmorpholine, N-octylamine, N,N-dibutyl formamide, and isonox 132, commonly used in lubricated condom formulations, were successfully characterized by DESI. The results suggest that DESI-MS is useful for identification of this type of evidence, and it has advantages over conventional extractive techniques, in terms of speed of analysis and ease of use.


Assuntos
Preservativos , Medicina Legal/métodos , Delitos Sexuais , Espectrometria de Massas por Ionização por Electrospray/métodos , Aminas/análise , Aminas/química , Dermatoglifia , Dimetilpolisiloxanos/análise , Dimetilpolisiloxanos/química , Humanos , Morfolinas/análise , Morfolinas/química , Nonoxinol/análise , Nonoxinol/química , Borracha/química
11.
Food Chem ; 135(3): 1855-60, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22953933

RESUMO

Commercial lecithins are composed mainly of phospholipids and triacylglycerols. The analysis of the commercial lecithins, including their fraction of phospholipids, normally involves laborious and expensive protocols. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) is shown to be an efficient technique for the analysis of lipids. Samples of commercial lecithins including standards, refined, deoiled and modified soy lecithin were tested. Characteristic profiles of phosphatidylcholines and triacylglycerols are detected by EASI(+)-MS, whereas EASI(-)-MS provided phosphatidylethanolamines, glycophospholipids and free fatty acids profiles. Acetylated lecithins also displayed characteristic acetylated derivatives. EASI-MS data was also compared to MALDI-MS, and found to display richer compositional information. The industrial process applied to lecithin fabrication was also characterised via typical EASI-MS profiles. EASI-MS both in its positive and negative ion modes offers a direct, fast and efficient technique able to characterise commercial lecithin.


Assuntos
Lecitinas/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Lecitinas/economia , Espectrometria de Massas por Ionização por Electrospray/instrumentação
12.
J Mass Spectrom ; 47(1): 1-6, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22282083

RESUMO

Venturi easy ambient sonic spray ionization mass spectrometry in both its liquid (V(L) -EASI-MS) and solid sample modes (V(S) -EASI-MS) is shown to provide nearly immediate and secure typification of woods, as demonstrated for Mahogany, an endangered and most valuable type of tropical wood. This reddish wood displays unique phytochemical markers (phragmalin-type limonoids) which are rapidly detected from the wood surface by V(S) -EASI-MS or from a simple methanol extract of a tiny wood chip by V(L) -EASI-MS. Unique profiles were obtained for Mahogany (Swietenia macrophylla) whereas genuine samples of six other similar types of woods, which are commonly falsified by artificial coloring and commercialized as Mahogany, display also typical but dissimilar pythochemical profiles as compared to that of the authentic wood. Variable and atypical chemical profiles were observed for artificially colored woods. Secure chemical characterization via V(S) -EASI-MS or V(s) -EASI-MS fingerprints of Mahogany and other types of woods with similar appearance should help to control the illegal logging and trade of this and other endangered woods and their falsification, and to create certified standards.


Assuntos
Meliaceae/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Madeira/classificação , Fracionamento Químico , Espécies em Perigo de Extinção , Limoninas/análise , Metanol , Árvores , Madeira/análise , Madeira/química
13.
Int J Food Microbiol ; 142(1-2): 156-63, 2010 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-20633943

RESUMO

Although the production of patulin in apple fruits is mainly by Penicillium expansum, there is no information on the ability of heat resistant moulds that may survive pasteurization to produce this mycotoxin in juice packages during storage and distribution. In this study, the production of patulin by Byssochlamys spp (Byssochlamys nivea FRR 4421, B. nivea ATCC 24008 and Byssochlamys fulva IOC 4518) in cloudy and clarified apple juices packaged in laminated paperboard packages or in polyethylene terephthalate bottles (PET) and stored at both 21 degrees C and 30 degrees C, was investigated. The three Byssochlamys strains were able to produce patulin in both cloudy and clarified apple juices. Overall, the lower the storage temperature, the lower the patulin levels and mycelium dry weight in the apple juices (p<0.05). The greatest variations in pH and degrees Brix were observed in the juices from which the greatest mycelium dry weights were recovered. The maximum levels of patulin recovered from the juices were ca. 150 microg/kg at 21 degrees C and 220 microg/kg at 30 degrees C. HPLC-UV, HPCL-DAD and mass spectrometry analyses confirmed the ability of B. fulva IOC 4518 to produce patulin. Due to the heat resistance of B. nivea and B. fulva and their ability to produce patulin either in PET bottles or in laminated paperboard packages, the control of contamination and the incidence of these fungi should be a matter of concern for food safety. Control measures taken by juice industries must also focus on controlling the ascospores of heat resistant moulds.


Assuntos
Bebidas/microbiologia , Byssochlamys/metabolismo , Embalagem de Alimentos , Malus/microbiologia , Patulina/metabolismo , Contaminação de Alimentos/análise , Patulina/análise , Temperatura
14.
J Agric Food Chem ; 57(10): 4030-4, 2009 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-19358529

RESUMO

Amazonian oils and fats display unique triacylglycerol (TAG) profiles and, because of their economic importance as renewable raw materials and use by the cosmetic and food industries, are often subject to adulteration and forgery. Representative samples of these oils (andiroba, Brazil nut, buriti, and passion fruit) and fats (cupuaçu, murumuru, and ucuúba) were characterized without pre-separation or derivatization via dry (solvent-free) matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Characteristic profiles of TAG were obtained for each oil and fat. Dry MALDI-TOF MS provides typification and direct and detailed information, via TAG profiles, of their variable combinations of fatty acids. A database from spectra could be developed and may be used for their fast and reliable typification, application screening, and quality control.


Assuntos
Gorduras/química , Contaminação de Alimentos/análise , Óleos de Plantas/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Triglicerídeos/análise , Bertholletia/química , Brasil , Ácidos Graxos/análise , Plantas/química , Controle de Qualidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA