RESUMEN
We investigated the synthesis of N-docosahexaenoylethanolamine (synaptamide) in neuronal cells from unesterified docosahexaenoic acid (DHA) or DHA-lysophosphatidylcholine (DHA-lysoPC), the two major lipid forms that deliver DHA to the brain, in order to understand the formation of this neurotrophic and neuroprotective metabolite of DHA in the brain. Both substrates were taken up in Neuro2A cells and metabolized to N-docosahexaenoylphosphatidylethanolamine (NDoPE) and synaptamide in a time- and concentration-dependent manner, but unesterified DHA was 1.5 to 2.4 times more effective than DHA-lysoPC at equimolar concentrations. The plasmalogen NDoPE (pNDoPE) amounted more than 80% of NDoPE produced from DHA or DHA-lysoPC, with 16-carbon-pNDoPE being the most abundant species. Inhibition of N-acylphosphatidylethanolamine-phospholipase D (NAPE-PLD) by hexachlorophene or bithionol significantly decreased the synaptamide production, indicating that synaptamide synthesis is mediated at least in part via NDoPE hydrolysis. NDoPE formation occurred much more rapidly than synaptamide production, indicating a precursor-product relationship. Although NDoPE is an intermediate for synaptamide biosynthesis, only about 1% of newly synthesized NDoPE was converted to synaptamide, possibly suggesting additional biological function of NDoPE, particularly for pNDoPE, which is the major form of NDoPE produced.
Asunto(s)
Ácidos Araquidónicos/biosíntesis , Ácidos Docosahexaenoicos/metabolismo , Endocannabinoides/biosíntesis , Etanolaminas/metabolismo , Lisofosfatidilcolinas/metabolismo , Neuronas/metabolismo , Animales , Ácidos Araquidónicos/antagonistas & inhibidores , Ácidos Araquidónicos/aislamiento & purificación , Bitionol/farmacología , Isótopos de Carbono , Línea Celular Tumoral , Cromatografía Liquida , Endocannabinoides/antagonistas & inhibidores , Endocannabinoides/aislamiento & purificación , Etanolaminas/antagonistas & inhibidores , Etanolaminas/aislamiento & purificación , Hexaclorofeno/farmacología , Cinética , Ratones , Neuronas/citología , Neuronas/efectos de los fármacos , Plasmalógenos/antagonistas & inhibidores , Plasmalógenos/biosíntesis , Plasmalógenos/aislamiento & purificación , Alcamidas Poliinsaturadas/antagonistas & inhibidores , Alcamidas Poliinsaturadas/aislamiento & purificación , Espectrometría de Masas en TándemRESUMEN
The major goal of this study was to determine the affinity pattern of brombuterol (BB) enantiomers toward various cyclodextrins (CD) and to evaluate the potential of NMR spectroscopy for understanding fine mechanisms of interactions between CDs and BB enantiomers. Separation of BB enantiomers was performed in a fused-silica capillary using a phosphate buffer, pH 2.5, at the room temperature in the normal polarity mode. It was shown once again that CE in combination with NMR spectroscopy represents a very sensitive tool for studies of affinity patterns and structure of CD complexes with chiral guests. Although opposite affinity patterns of BB enantiomers were observed toward native ß- and γ-CDs, no significant differences between the structures of the complexes of these two CDs with BB were detected by NMR spectroscopy. In contrary to this, the opposite affinity pattern of BB enantiomers toward ß-CD and its two sulfated derivatives, heptakis (2,3-O-diacetyl-6-sulfo)-ß-CD (HDAS-ß-CD) and heptakis (2-O-methyl-3,6-di-O-sulfo)-ß-CD (HMDS-ß-CD) was associated with major differences in the structure of the complexes. In addition, it was shown again that HMDS-ß-CD provides separation of enantiomers without formation of inclusion-type complex with the chiral analyte.
Asunto(s)
Compuestos de Anilina/química , Compuestos de Anilina/aislamiento & purificación , Ciclodextrinas/química , Electroforesis Capilar/métodos , Etanolaminas/química , Etanolaminas/aislamiento & purificación , Espectroscopía de Resonancia Magnética/métodos , Compuestos de Anilina/análisis , Etanolaminas/análisis , Concentración de Iones de Hidrógeno , EstereoisomerismoRESUMEN
Stripping crystallization (SC) is introduced in this work for chiral purification of R-phenylglycinol from the enantiomer mixture with an initial concentration ranging from 0.90 to 0.97. As opposed to the solidâ»liquid transformation in melt crystallization, the three-phase transformation occurs in SC at low pressures during the cooling process. SC combines melt crystallization and vaporization to produce a crystalline product and mixture vapor from a mixture melt due to the three-phase transformation. Thermodynamic calculations were applied to determine the operating pressure for the three-phase transformation during the cooling process in the SC experiments. To consider the possible deviations between the calculated and the actual three-phase transformation conditions, the product purity and the recovery ratio of R-phenylglycinol were investigated within a range of operating pressures during the cooling process.
Asunto(s)
Etanolaminas/química , Etanolaminas/aislamiento & purificación , Algoritmos , Cristalización , Modelos Químicos , Estructura Molecular , TermodinámicaRESUMEN
It can be established that at least two of the writers of the article published in 'Inflammopharmacology', title: 'Palmitoylethanolamide (PEA), a naturally occurring disease-modifying agent in neuropathic pain' have a direct connection to the companies Epitech and Innovet. These companies produce micronized and ultra-micronized PEA. Therefore it is of eminent importance to determine whether the statements in this paper have also taken into consideration the European guidelines for Good Clinical Practice and the codes of good scientific practices. This is very questionable. A minimum condition in clinical studies for proving the claim that PEA in its micronized and ultra-micronized formulations works better than in its pure form or in other formulations is that a comparison be made between: PEA in pure form or in other formulations, on the one hand; PEA in the micronized and ultra-micronized formulations, on the other hand. This minimum condition is not complied with. Based on additional studies discussed in this commentary and in view of the effects of ultra-micronization on the parameters discussed, as well as the potential side-effects of additives such as excipients and herbal extracts added to the products cited in the article, the preference should be for the time being to treat patients with pure PEA without any of these additives.
Asunto(s)
Química Farmacéutica/métodos , Contaminación de Medicamentos , Endocannabinoides/síntesis química , Endocannabinoides/aislamiento & purificación , Etanolaminas/síntesis química , Etanolaminas/aislamiento & purificación , Ácidos Palmíticos/síntesis química , Ácidos Palmíticos/aislamiento & purificación , Amidas , Animales , Química Farmacéutica/normas , Contaminación de Medicamentos/prevención & control , Humanos , Tamaño de la PartículaRESUMEN
BACKGROUND: Artemether-lumefantrine (AL) combination therapy is now the most used anti-malarial treatment in the world. Quality control of AL formulations is still a major challenge in developing countries. Until now, only liquid chromatographic methods have been reported in the literature for their analysis. Capillary electrophoretic methods, which present various advantages (low price of capillary, low volumes of electrolyte consumption), may be an alternative to liquid chromatography methods. In this paper, a reliable method was developed and validated for the determination of AL in commercial fixed-dose combination tablets commercialized in Côte d'Ivoire. METHODS: Artemether and lumefantrine were determined by microemulsion electrokinetic chromatography using short-end injection procedure. The two analytes were extracted from tablets by acidified methanol. Pyrimethamine was used as internal standard. Separation was carried out in an uncoated fused silica capillary, 30 cm long × 50 µm internal diameter, using an effective length of 10 cm and a microemulsion composed of octane, butanol, sodium dodecyl sulfate and borate buffer as background electrolyte, a - 500 V x cm(-1) electric field and a detection wavelength of 214 nm. RESULTS: Artemether, lumefantrine and pyrimethamine were separated in 6 min. The method was reliable with respect to selectivity towards formulation excipients, linearity of the response function (r2 > 0.998), recovery studies from synthetic tablets (in the range 99-101%), repeatability (relative standard deviation 1-3%, n = 7 analytical procedures). Application to four commercial formulations containing 20/120 mg of AL per tablet gave a content in good agreement with the declared content. However, the electropherogram of one tablet formulation showed the presence of an ingredient which was not declared. CONCLUSION: The developed MEEKC method can be proposed as an alternative method to liquid chromatography for the determination of artemether and lumefantrine in fixed-dose combination tablet formulations.
Asunto(s)
Antimaláricos/análisis , Artemisininas/análisis , Cromatografía Capilar Electrocinética Micelar/métodos , Etanolaminas/análisis , Fluorenos/análisis , Antimaláricos/química , Antimaláricos/aislamiento & purificación , Combinación Arteméter y Lumefantrina , Artemisininas/química , Artemisininas/aislamiento & purificación , Combinación de Medicamentos , Emulsiones/química , Etanolaminas/química , Etanolaminas/aislamiento & purificación , Fluorenos/química , Fluorenos/aislamiento & purificación , Límite de Detección , Modelos Lineales , Reproducibilidad de los Resultados , ComprimidosRESUMEN
The G protein-coupled receptor 119 (GPR119) is highly expressed in pancreatic ß-cells. On activation, this receptor enhances the effect of glucose-stimulated insulin secretion (GSIS) via the elevation of intracellular cAMP concentrations. Although GPR119 agonists represent promising oral antidiabetic agents for the treatment of type 2 diabetes therapy, they suffer from the inability to adequately directly preserve ß-cell function. To identify a new structural class of small-molecule GPR119 agonists with both GSIS and the potential to preserve ß-cell function, we screened a library of synthetic compounds and identified a candidate molecule, AS1269574, with a 2,4,6-tri-substituted pyrimidine core. Here, we examined the preliminary in vitro and in vivo effects of AS1269574 on insulin secretion and glucose tolerance. AS1269574 had an EC(50) value of 2.5µM in HEK293 cells transiently expressing human GPR119 and enhanced insulin secretion in the mouse pancreatic ß-cell line MIN-6 only under high-glucose (16.8mM) conditions. This contrasted with the action of the sulfonylurea glibenclamide, which also induced insulin secretion under low-glucose conditions (2.8mM). In in vivo studies, a single administration of AS1269574 to normal mice reduced blood glucose levels after oral glucose loading based on the observed insulin secretion profiles. Significantly, AS1269574 did not affect fed and fasting plasma glucose levels in normal mice. Taken together, these results suggest that AS1269574 represents a novel structural class of small molecule, orally administrable GPR119 agonists with GSIS and promising potential for the treatment of type 2 diabetes.
Asunto(s)
Etanolaminas/farmacología , Glucosa/farmacología , Hipoglucemiantes/farmacología , Células Secretoras de Insulina/efectos de los fármacos , Insulina/metabolismo , Pirimidinas/farmacología , Receptores Acoplados a Proteínas G/agonistas , Animales , Glucemia/efectos de los fármacos , Línea Celular , Etanolaminas/química , Etanolaminas/aislamiento & purificación , Ayuno , Humanos , Hipoglucemiantes/química , Secreción de Insulina , Células Secretoras de Insulina/metabolismo , Ratones , Ratones Endogámicos ICR , Pirimidinas/química , Pirimidinas/aislamiento & purificaciónRESUMEN
In this study, amylose- and cellulose-phenylcarbamate-based chiral columns with different chiral-selector (CS) chemistries were compared to each other for the separation of enantiomers of basic chiral analytes in acetonitrile and aqueous-acetonitrile mobile phases in HPLC. For two chemistries the amylose-based columns with coated and immobilized CSs were also compared. The comparison of CSs containing only electron-donating or electron-withdrawing substituents with those containing both electron-donating and electron-withdrawing substituents showed opposite results for the studied set of chiral analytes in the case of amylose and cellulose derivatives. Along with the chemistry of CS the focus was on the behavior of polysaccharide phenylcarbamates in acetonitrile versus aqueous acetonitrile as eluents. In agreement with earlier results, it was found that in contrast to the commonly accepted view, polysaccharide phenylcarbamates do not behave as typical reversed-phase materials for basic analytes either. In the range of water content in the mobile phase of up to 20-30% v/v the behavior of these CSs is similar to hydrophilic interaction liquid chromatography (HILIC)-type adsorbents. This means that with increasing water content in the mobile phase up to 20-30% v/v, the retention of analytes mostly decreases. The important finding of this study is that the separation efficiency improves for most analytes when switching from pure acetonitrile to aqueous acetonitrile. Therefore, in spite of reduced retention, the separation of enantiomers improves and thus, the HILIC-range of mobile phase composition, offering shorter analysis time and better peak resolution, is advantageous over pure polar-organic solvent mode. Interesting examples of enantiomer elution order (EEO) reversal were observed for some analytes based on the content of water in the mobile phase on Lux Cellulose-1 and Lux Amylose-2 columns.
Asunto(s)
Amilosa/química , Celulosa/química , Cromatografía Líquida de Alta Presión/métodos , Preparaciones Farmacéuticas/aislamiento & purificación , Fenilcarbamatos/química , Acetonitrilos/química , Electrones , Etanolaminas/análisis , Etanolaminas/aislamiento & purificación , Preparaciones Farmacéuticas/análisis , Propanolaminas/análisis , Propanolaminas/aislamiento & purificación , Propranolol/análisis , Propranolol/aislamiento & purificación , Estereoisomerismo , Agua/químicaRESUMEN
The continuous nature of micro free-flow electrophoresis (mu-FFE) was used to monitor the effect of a gradient of buffer conditions on the separation. This unique application has great potential for fast optimization of separation conditions and estimation of equilibrium constants. COMSOL was used to model pressure profiles in the development of a new mu-FFE design that allowed even application of a buffer gradient across the separation channel. The new design was fabricated in an all glass device using our previously published multiple-depth etch method (Fonslow, B. R.; Barocas, V. H.; Bowser, M. T. Anal. Chem. 2006, 78, 5369-5374, ref 1). Fluorescein solutions were used to characterize the applied gradients in the separation channel. Linear gradients were observed when buffer conditions were varied over a period of 5-10 min. The effect of a gradient of 0-50 mM hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the separation of a group of 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) labeled primary amines was monitored as a proof of concept experiment. Direct comparisons to capillary electrophoresis (CE) separations performed under the same conditions were made. Gradient mu-FFE recorded 60 separations during a 5 min gradient allowing nearly complete coverage across a range of HP-beta-CD concentrations. In comparison, 4 h were required to assess 15 sets of conditions across the same range of HP-beta-CD concentrations using CE. Qualitatively, mu-FFE separations were predictive of the migration order and spacing of peaks in CE electropherograms measured under the same conditions. Data were fit to equations describing 1:1 analyte-additive binding to allow a more quantitative comparison between gradient mu-FFE and CE.
Asunto(s)
Aminoácidos/aislamiento & purificación , Electroforesis/métodos , 2-Hidroxipropil-beta-Ciclodextrina , 4-Cloro-7-nitrobenzofurazano/análogos & derivados , 4-Cloro-7-nitrobenzofurazano/química , Aminoácidos/química , Tampones (Química) , Electroforesis/instrumentación , Etanolaminas/química , Etanolaminas/aislamiento & purificación , Fluoresceína/química , Colorantes Fluorescentes/química , Cinética , Modelos Teóricos , Viscosidad , beta-Ciclodextrinas/químicaRESUMEN
PURPOSE: Measure concentrations of the neurogenic, pro-neurogenic, pro-synaptogenic and anti-inflammatory mediator N-docosahexaenoylethanolamine (synaptamide) in relation to its precursor docosahexaenoic acid (DHA) in breast milk. DESIGN AND METHODS: Postpartum women were recruited prior to discharge. We supplemented half the subjects with omega-3 fatty acids. Breast milk samples were collected at 1, 4 and 8 weeks. Synaptamide and DHA concentrations were determined by liquidchromatography/tandem mass spectrometry (LC-MS/MS) and gas chromatography, respectively. RESULTS: Synaptamide was detected in all breast milk samples. The concentration ranged from 44 to 257 fmol/mL. Omega-3 fatty acid supplementation did not affect DHA or synaptamide concentration in breast milk due to a high-DHA-containing diet self-selected by control mothers. Nevertheless, synaptamide levels significantly correlated with DHA concentration in breast milk (râ¯=â¯0.624, Pâ¯<â¯0.001). CONCLUSION: This is the first demonstration of detectable concentrations of synaptamide in human breast milk. Although the attempt to raise the milk DHA content by omega-3 fatty acid supplementation was not successful in the current study, the positive correlation observed between synaptamide and DHA concentration suggests that synaptamide levels in human milk can be raised by proper omega-3 fatty acid supplementation that is known to increase DHA.
Asunto(s)
Ácidos Docosahexaenoicos/química , Etanolaminas/química , Ácidos Grasos Omega-3/administración & dosificación , Leche Humana/química , Adulto , Ácidos Docosahexaenoicos/aislamiento & purificación , Etanolaminas/aislamiento & purificación , Femenino , Cromatografía de Gases y Espectrometría de Masas , Humanos , Leche Humana/efectos de los fármacos , Periodo Posparto/efectos de los fármacos , Espectrometría de Masas en TándemRESUMEN
A bioanalytical method for the determination of lumefantrine in 100 microl blood applied onto sampling paper, by solid-phase extraction and liquid chromatography, has been developed and validated. Whatman 31 ET Chr sampling paper was pre-treated with 0.75 M tartaric acid before sampling capillary blood to enable a high recovery of lumefantrine. Lumefantrine was extracted from the sampling paper, then further purified using solid-phase extraction and finally quantified with HPLC. The between-day variation was below 10% over the range 0.4-25 microM. The lower limit of quantification was 0.25 microM in 100 microl capillary blood. No decrease in lumefantrine concentration in dried blood spot is seen after 4 months storage at 22 degrees C. The method was also evaluated in field samples from patients in Tanzania after treatment with lumefantrine/artemether. Lumefantrine could be estimated accurately enough to assess bioavailability and treatment compliance on day 7 (i.e. 4 days after the last dose) after a standard regimen with the lumefantrine/artemether combination.
Asunto(s)
Antimaláricos/sangre , Antimaláricos/aislamiento & purificación , Cromatografía Liquida/métodos , Etanolaminas/sangre , Etanolaminas/aislamiento & purificación , Fluorenos/sangre , Fluorenos/aislamiento & purificación , Humanos , Lumefantrina , Papel , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Extracción en Fase SólidaRESUMEN
A selective analytical method based on packed-fiber solid-phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry (PFSPE-UPLC-MS/MS) has been developed for determination of six ß-agonists (clorprenaline, bambuterol, clenbuterol, brombuterol, mabuterol, and penbuterol) in pork tissue. Polystyrene-polymeric crown ether (PS-PCE) composite nanofibers were fabricated by electrospinning and utilized to prepare the homemade extraction columns. With optimal conditions, all analytes were separated very well and the blank pork did not disturb the determination, and the linearity is good in a range of 5.0µg/kg-25.0µg/kg. The recoveries were 79.3-110.1%. RSDs for intra-day were in the range of 1.5-10.5% and RSDs for inter-day were 4.7-11.8%. Above all, only 5mg of sorbent and 200µL of elution solvent were favorable to directly extract all analytes in a complex matrix. The method is simple and cost-effective, and has the potential to be applied to quantitatively analyze the concentrations of polar species in food samples containing complex matrix.
Asunto(s)
Agonistas Adrenérgicos beta/química , Agonistas Adrenérgicos beta/aislamiento & purificación , Cromatografía Líquida de Alta Presión/métodos , Carne/análisis , Extracción en Fase Sólida/métodos , Espectrometría de Masas en Tándem/métodos , Drogas Veterinarias/aislamiento & purificación , Compuestos de Anilina/análisis , Compuestos de Anilina/aislamiento & purificación , Animales , Clenbuterol/análogos & derivados , Clenbuterol/análisis , Clenbuterol/aislamiento & purificación , Residuos de Medicamentos/química , Residuos de Medicamentos/aislamiento & purificación , Etanolaminas/análisis , Etanolaminas/aislamiento & purificación , Contaminación de Alimentos/análisis , Límite de Detección , Nanofibras/análisis , Polímeros/análisis , Poliestirenos/química , Extracción en Fase Sólida/instrumentación , Porcinos , Drogas Veterinarias/químicaRESUMEN
A capillary electrophoresis method, using field-amplified sample injection (FASI), was developed for separation and determination of some beta 2-agonists, such as cimaterol, clenbuterol and salbutamol. The optimum conditions for this system had been investigated in detail. The precision of the migration time, peak height and accuracy were determined in both intra-day (n = 5) and inter-day (n = 15) assays. Under the optimum conditions, the detection limits (defined as S/N = 3) of this method were found to be lower than 2.0 ng/mL for all of these three beta 2-agonists, which were much lower than that of the conventional electro-migration injection method, the enhancement factors were greatly improved to be 30-40-fold. Such lower detection limit lets this method to be suitable for determination of above-mentioned beta 2-agonists in the urine sample. The mean recoveries in urine were higher than 96.2%, 95.6% and 95.3% for cimaterol, clenbuterol and salbutamol, respectively, with relative standard deviations lower than 3.5%.
Asunto(s)
Albuterol/análisis , Clenbuterol/análisis , Electroforesis Capilar/métodos , Etanolaminas/análisis , Albuterol/aislamiento & purificación , Albuterol/orina , Clenbuterol/aislamiento & purificación , Clenbuterol/orina , Etanolaminas/aislamiento & purificación , Etanolaminas/orina , Humanos , Reproducibilidad de los ResultadosRESUMEN
[reaction: see text] The marine sponge derived beta2-adrenoceptor agonist S1319 has been synthesized following a six-step linear sequence. Central to the approach employed is the formation of a 7-lithiated-2,4-dialkoxybenzothiazole intermediate obtained via a directed-lithiation/benzyne-mediated cyclization reaction. The incorporation of a tert-butyl ether residue into the cyclization precursor for the pivotal ring-closing step has been shown to significantly increase the efficiency of the reaction by the suppression of a competing directed ortho-lithiation reaction.
Asunto(s)
Agonistas Adrenérgicos beta/síntesis química , Etanolaminas/síntesis química , Poríferos/química , Tiazoles/síntesis química , Agonistas Adrenérgicos beta/química , Agonistas Adrenérgicos beta/aislamiento & purificación , Animales , Benzotiazoles , Ciclización , Etanolaminas/química , Etanolaminas/aislamiento & purificación , Estructura Molecular , Tiazoles/química , Tiazoles/aislamiento & purificaciónRESUMEN
Amosulalol is an antihypertensive drug with selective postsynaptic alpha 1 and non-selective beta blocking effects. A simple solid-phase extraction and high-performance liquid chromatographic (HPLC) method has been developed and validated for the quantitative determination of amosulalol in human plasma. A reversed phase C18 column was used for the separation of amosulalol and ethyl paraben (internal standard) with a mobile phase composed of 0.025 M phosphate buffer (pH 6.0).acetonitrile (73:27, v/v) at a flow rate of 1.5 mL/min. The ultraviolet detector was operated at the 272 nm wavelength. Intra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification of 30 ng/mL. Recovery of amosulalol from human plasma was >95.6%. Amosulalol was stable in human plasma under various storage conditions. This method was used successfully for a pharmacokinetic study in plasma after oral administration of a single 20 mg dose of amosulalol hydrochloride to 16 healthy volunteers.
Asunto(s)
Antihipertensivos/sangre , Cromatografía Líquida de Alta Presión/métodos , Etanolaminas/sangre , Adulto , Antihipertensivos/aislamiento & purificación , Antihipertensivos/farmacocinética , Etanolaminas/aislamiento & purificación , Etanolaminas/farmacocinética , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Present study aimed at graphene surface modification to achieve selective analyte binding in dispersive solid phase extraction. Magnetic graphene - polystyrene sulfonic acid (MG-PSS) cation exchange nano-composite was prepared by non-covalent wrapping method. Composite was characterized by FT-IR and zeta potential. Material exhibited good dispersion in water and high exchange capacity of 1.97±0.16mMg(-1). Prepared nano-sorbent was then exploited for the cation exchange extraction and gas chromatography mass spectrometric analysis of Chemical Weapons Convention relevant aminoalcohols and ethanolamines from aqueous samples. Extraction parameters such as sorbent amount, extraction time, desorption conditions and sample pH were optimized and effect of common matrix interferences such as polyethylene glycol and metal salts was also studied. Three milligram of sorbent per mL of sample with 20min of extraction time at room temperature afforded 70-81% recoveries of the selected analytes spiked at concentration level of 1µgmL(-1). Method showed good linearity in the studied range with r(2)≥0.993. The limits of detection and limits of quantification ranged from 23 to 54ngmL(-1) and 72 to 147ngmL(-1), respectively. The relative standard deviation for intra- and inter-day precision ranged from 4.6 to 10.2% and 7.4 to 14.8% respectively. Applicability of the method to different environmental samples as well as the proficiency tests conducted by the Organization for the Prohibition of Chemical Weapons (OPCW) was also ascertained.
Asunto(s)
Amino Alcoholes/aislamiento & purificación , Monitoreo del Ambiente/métodos , Etanolaminas/aislamiento & purificación , Grafito/química , Nanocompuestos/química , Poliestirenos/química , Agua/química , Amino Alcoholes/análisis , Etanolaminas/análisis , Cromatografía de Gases y Espectrometría de Masas , Extracción en Fase Sólida , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/análisisRESUMEN
Recent reports have suggested that N-arachidonoylethanolamine (anandamide) acts as an endogenous ligand for cannabinoid receptors in mammalian brain. Here we describe methods for the extraction, purification and analysis of anandamide and related N-fatty acyl-ethanolamines (NAEs). Liquid-phase extraction, silica gel G column chromatography and thin-layer chromatography (TLC) were employed for sample fractionation. Three analytical high-performance liquid chromatography (HPLC) methods for purification of NAEs were developed. Finally, analyses of NAEs by gas chromatography/mass spectrometry (GC/MS) are described. The applications of these analytical methods to the identification of anandamide and related NAEs in cell cultures as well as of artifacts in biosynthetic studies are described.
Asunto(s)
Ácidos Araquidónicos/química , Cannabinoides/química , Etanolaminas/química , Animales , Ácidos Araquidónicos/aislamiento & purificación , Artefactos , Encéfalo/citología , Encéfalo/metabolismo , Cannabinoides/aislamiento & purificación , Células Cultivadas , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Cromatografía en Capa Delgada , Endocannabinoides , Etanolaminas/síntesis química , Etanolaminas/aislamiento & purificación , Cromatografía de Gases y Espectrometría de Masas , Estructura Molecular , Alcamidas Poliinsaturadas , Ratas , Gel de Sílice , Dióxido de SilicioRESUMEN
A mass fragmentographic method was used for determination of low molecular weight compounds in perfusates collected in vivo in the pigeon optic tectum by a push-pull cannula technique. 2-Aminoethanol (ethanolamine) could be collected under resting conditions (5.6 +/- 0.09 pmol/min). Electrical stimulation of optic nerve induced a 2.3-fold increase of the tectal ethanolamine outflow whereas that of GABA was not affected. Ethanolamine applied iontophoretically to tectal neurons did not influence their spontaneous discharge; however, their glutamate-induced excitation as well as the GABA-induced depression were enhanced if ethanolamine was applied simultaneously. It is suggested that optic nerve stimulation exerts a neuromodulatory effect on tectal neurons.
Asunto(s)
Etanolaminas/fisiología , Neuronas/fisiología , Colículos Superiores/fisiología , Animales , Columbidae , Depresión de Propagación Cortical , Estimulación Eléctrica , Etanolamina , Etanolaminas/aislamiento & purificación , Etanolaminas/farmacología , Colículos Superiores/efectos de los fármacos , Ácido gamma-Aminobutírico/farmacologíaRESUMEN
The term amines encompasses a wide variety of compounds: monovalent or polyvalent amines, hydrophobic or hydrophilic amines, and combinations of all of these. Due to their charge, polyvalent amines such as the biogenic amines have very strong cation-exchange interaction with the cation-exchange groups in the stationary phase. Very high acid concentrations are required to elute them effectively from a high-capacity, carboxylated cation-exchange column. The eluent must contain a divalent ion to elute them from a sulfonated cation-exchange column due to its selectivity. Chromatography for these amines with a new "tailored" amine column of moderate capacity using a simple acidic eluent is described. The hydrophobic nature of other amines, such as long-carbon-chained amines, results in partitioning into the polymeric substrate of previous carboxylated stationary phases, so that organic solvent is required to elute them effectively. The substrate resin of this new "tailored" amine column is first coated so that, when it is functionalized in a subsequent step, this type of interaction is minimized. Examples are given. Methods that require eluent gradients and/or step changes of eluent concentration are especially well suited to this column because the background conductivity remains almost unchanged under gradient conditions.
Asunto(s)
Aminas/aislamiento & purificación , Resinas de Intercambio de Catión , Cromatografía por Intercambio Iónico/métodos , Alquilación , Aminas/química , Aminas Biogénicas/aislamiento & purificación , Cationes/aislamiento & purificación , Diaminas/aislamiento & purificación , Etanolaminas/aislamiento & purificación , Etilaminas/aislamiento & purificación , Concentración de Iones de Hidrógeno , Compuestos de Amonio Cuaternario/aislamiento & purificación , Sensibilidad y Especificidad , Agua/químicaRESUMEN
N-acyl phosphatidylethanolamine (N-acyl PE) and free N-acylethanolamine (NAE) in mouse peritoneal macrophages were identified and quantified by gas chromatography-mass spectrometry (GC-MS) of tertbutyldimethylsilyl derivatives in the presence of internal standards synthesized from [1,1,2,2-2H4]ethanolamine. N-acyl PE was present at a level of 123-187 pmol/mumol lipid P (521-768 pmol/10(8) cells), with arachidonic acid making up about 3-4% of the N-acyl moieties. NAE, on the other hand, was present at a level of only 17-30 pmol/mumol lipid P (70-121 pmol/10(8) cells), with N-arachidonoylethanolamine (anandamide) making up less than 1% of total NAE. Use of deuterium labeled internal standards and optimization of GC-MS conditions makes it possible to detect as little as 0.1 ng of saturated and 1 ng (3 pmol) of polyunsaturated NAEs in a lipid extract. The present method can be used to determine agonist-induced changes in the levels and compositions of N-acyl PE and NAE.
Asunto(s)
Ácidos Araquidónicos/análisis , Etanolaminas/análisis , Macrófagos Peritoneales/química , Aciltransferasas/metabolismo , Animales , Deuterio , Endocannabinoides , Etanolaminas/aislamiento & purificación , Ácidos Grasos/química , Cromatografía de Gases y Espectrometría de Masas , Ratones , Compuestos de Organosilicio/síntesis química , Fosfatidiletanolaminas/análisis , Fosfatidiletanolaminas/aislamiento & purificación , Alcamidas PoliinsaturadasRESUMEN
N-Acylethanolamines (NAEs) are an important family of lipid-signaling molecules. Arachidonylethanolamide (anandamide) (AEA), palmitoylethanolamide (PEA), and oleoylethanolamide (OEA) are co-produced from similar phospholipid precursors when neurons are stimulated. AEA is an endogenous agonist (endocannabinoid) for cannabinoid receptors. It binds with higher affinity to type CB1 than to type CB2 cannabinoid receptors. PEA does not bind to CB1, while the hypothesis that it reacts with putative CB2-like receptors has been questioned. OEA does not activate currently known cannabinoid receptors, but it mimics the effects of AEA and cannabinoids in reducing the fertilizing capacity of sea urchin sperm. OEA and PEA also act as entourage compounds by inhibiting the hydrolysis of AEA by fatty acid amide hydrolase. Cannabinoid receptors and/or AEA are present in mammalian reproductive organs including the testis, epididymis, prostate, ovary, uterus, sperm, preimplantation embryo and placenta, as well as prostatic and mammary carcinomas. We now report that analysis by high-performance liquid chromatography/mass spectrometry (HPLC/MS) shows the presence of AEA, PEA, and OEA in human seminal plasma, mid-cycle oviductal fluid, follicular fluid, amniotic fluid, milk, and fluids from malignant ovarian cysts. Previous studies showed that AEA-signaling via cannabinoid receptors regulates capacitation and fertilizing potential of human sperm, early embryonic development and blastocyst implantation into the uterine mucosa of rodents, as well as proliferation of human mammary and prostatic carcinomas. Current results imply that NAEs also may modulate follicular maturation and ovulation, normal and pathological ovarian function, placental and fetal physiology, lactation, infant physiology, and behavior. Collectively, these findings suggest that NAEs in human reproductive fluids may help regulate multiple physiological and pathological processes in the reproductive system, and imply that exogenous cannabinoids delivered by marijuana smoke might impact these processes. This study has potential medical and public policy ramifications because of the incidence of marijuana abuse by adolescents and adults in our society, previously documented reproductive effects of marijuana, and the ongoing debate about medicinal use of marijuana and cannabinoids.