RESUMEN
A method has been developed for extracting poppy alkaloids from oily matrices, specifically lipid residues associated with archaeological ceramics. The protocol has been applied to fresh and artificially aged poppyseed oil and to residue from a Late Bronze Age Cypriot juglet in the collections of the British Museum. The juglet is of a type that has been linked with ancient trade in opium due to its poppy-head shape and wide distribution; it is a rare example of an intact vessel with contents sealed inside. Bulk analysis of the residue by GC-EI-MS and pyGC-EI-MS indicated a degraded plant oil and possible presence of papaverine. Analysis of the alkaloid extracts by HPLC-ESI-MS using both triple quadrupole and FTICR mass spectrometers detected the five primary opium alkaloids in fresh poppyseed oil and papaverine in most of the aged samples. Papaverine and thebaine were detected in the juglet residue, providing the first rigorous chemical evidence to support a link between this vessel type and opium, or at least poppies. The association of opium with oil raises new questions about the ancient purpose of the commodities within these vessels, and the low levels (ng g-1) of opiates detected in this unusually well-preserved residue shed doubt on the scope for their detection in more fragmentary ceramic remains (potsherds). Papaverine was found to exhibit challenging carryover behaviour in all the analytical methods used in this study. The phenomenon has not been reported before and should be considered in future analyses of this analyte in all application areas.
Asunto(s)
Cerámica/análisis , Opio/análisis , Papaverina/análisis , Aceites de Plantas/análisis , Extracción en Fase Sólida/métodos , Tebaína/análisis , Arqueología/métodos , Cromatografía Líquida de Alta Presión/métodos , Cromatografía de Gases y Espectrometría de Masas/métodos , Límite de Detección , Papaver/química , Espectrometría de Masa por Ionización de Electrospray/métodosRESUMEN
Pharmaceuticals are ubiquitous in the natural environment with concentrations expected to rise as human population increases. Environmental risk assessments are available for a small portion of pharmaceuticals in use, raising concerns over the potential risks posed by other drugs that have little or no data. With >1900 active pharmaceutical ingredients in use, it would be a major task to test all of the compounds with little or no data. Desk-based prioritization studies provide a potential solution by identifying those substances that are likely to pose the greatest risk to the environment and which, therefore, need to be considered a priority for further study. The aim of this review was to (1) provide an overview of different prioritization exercises performed for pharmaceuticals in the environment and the results obtained; and (2) propose a new holistic risk-based prioritization framework for drugs in the environment. The suggested models to underpin this framework are discussed in terms of validity and applicability. The availability of data required to run the models was assessed and data gaps identified. The implementation of this framework may harmonize pharmaceutical prioritization efforts and ensure that, in the future, experimental resources are focused on molecules, endpoints, and environmental compartments that are biologically relevant.
Asunto(s)
Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Medición de Riesgo/métodos , Humanos , Modelos TeóricosRESUMEN
Polyamines (PAs) are ubiquitous polycations derived from basic l-amino acids whose physiological roles are still being defined. Their biosynthesis and functions in nitrogen-fixing rhizobia such as Sinorhizobium meliloti have not been extensively investigated. Thin layer chromatographic and mass spectrometric analyses showed that S. meliloti Rm8530 produces the PAs, putrescine (Put), spermidine (Spd) and homospermidine (HSpd), in their free forms and norspermidine (NSpd) in a form bound to macromolecules. The S. meliloti genome encodes two putative ornithine decarboxylases (ODC) for Put synthesis. Activity assays with the purified enzymes showed that ODC2 (SMc02983) decarboxylates both ornithine and lysine. ODC1 (SMa0680) decarboxylates only ornithine. An odc1 mutant was similar to the wild-type in ODC activity, PA production and growth. In comparison to the wild-type, an odc2 mutant had 45â% as much ODC activity and its growth rates were reduced by 42, 14 and 44â% under non-stress, salt stress or acid stress conditions, respectively. The odc2 mutant produced only trace levels of Put, Spd and HSpd. Wild-type phenotypes were restored when the mutant was grown in cultures supplemented with 1 mM Put or Spd or when the odc2 gene was introduced in trans. odc2 gene expression was increased under acid stress and reduced under salt stress and with exogenous Put or Spd. An odc1 odc2 double mutant had phenotypes similar to the odc2 mutant. These results indicate that ODC2 is the major enzyme for Put synthesis in S. meliloti and that PAs are required for normal growth in vitro.
Asunto(s)
Ornitina Descarboxilasa/metabolismo , Poliaminas/metabolismo , Sinorhizobium meliloti/crecimiento & desarrollo , Sinorhizobium meliloti/metabolismo , Aminoácidos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Medios de Cultivo , Regulación Bacteriana de la Expresión Génica , Prueba de Complementación Genética , Mutación , Ornitina Descarboxilasa/genética , Poliaminas/análisis , Putrescina/metabolismo , Sinorhizobium meliloti/enzimología , Espermidina/análogos & derivados , Espermidina/metabolismo , Transcripción GenéticaRESUMEN
AIM OF THE STUDY: Genista tenera is a plant endemic to the island of Madeira and is used in folk medicine to control diabetes. In the present work we evaluate the antihyperglycaemic activity of its n-butanol extract and determine its chromatographic profile. In addition, this extract, the ethyl acetate and diethyl ether plant extracts were studied in order to assess the plant antioxidant and acetylcholinesterase inhibitory activities, as well as its cyto- and genotoxicities. MATERIALS AND METHODS: HPLC-DAD-ESI-MS was used to analyze the flavonoid profile of the n-butanol extract. The antihyperglycaemic activity of this extract was performed over streptozotocin induced diabetic Wistar rats (200 mg/kg, bw/day), for 15 days. Antioxidant activity (DPPH assay) and acetylcholinesterase inhibitory effect (Ellman method) were also performed. Acute cytotoxicity and genotoxicity were assessed by proliferative index quantification and the short-term chromosomal aberration technique, after exposure of lymphocytes to the extracts. RESULTS AND CONCLUSIONS: The n-butanol extract, where 21 monoglycosyl and 12 diglycosyl flavonoids were detected, significantly lowered blood glucose levels, bringing them to normal values after 15 days of treatment. The best radical scavenging activity was observed for the ethyl acetate extract (48.7% at 139.1 microg/mL), which was also the most effective one at the minimal concentration tested. The highest acetylcholinesterase inhibitory activity (77.0% at 70.0 microg/mL) was also obtained with the ethyl acetate extract. In vitro toxicity studies showed no evidence for acute cytotoxicity or genotoxicity. This is the first report on antidiabetic activity of genus Genista.
Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Flavonoides/uso terapéutico , Genista , Hipoglucemiantes/uso terapéutico , Fitoterapia , Extractos Vegetales/uso terapéutico , Animales , Antioxidantes/farmacología , Glucemia , Inhibidores de la Colinesterasa/farmacología , Flavonoides/farmacología , Hipoglucemiantes/efectos adversos , Hipoglucemiantes/farmacología , Extractos Vegetales/efectos adversos , Extractos Vegetales/química , Extractos Vegetales/farmacología , RatasRESUMEN
This work reports the development and optimisation of a negative ion mode on-line LC-ESI-MS/MS method for the sensitive targeted analysis of the key glycolytic intermediates, sugars and sugar phosphates from plants, using a porous graphitic carbon (PGC) stationary phase and an MS compatible mobile phase. Using this newly developed method, separation and detection of a solution of standard compounds is achieved in less than 20min. Target metabolite compounds were identified in plant extracts from their characteristic retention times, and product ion spectra. This on-line PGC-ESI-MS/MS method shows good linearity over the concentration range 0-100microM, selectivity, short analysis time, and limits of detection of 0.1microM for disaccharides trehalose (Tre), sucrose (Suc), and maltose, and 1.5microM for hexose phosphates fructose-6-phosphate (Fru6P), glucose-1-phosphate (Glc1P), and glucose-6-phosphate (Glc6P), and phosphoenolpyruvate (PEP). This paper describes details of our method and its application to the simultaneous quantitative analysis of soluble sugars and sugar phosphates from Arabidopsis thaliana tissues. We have demonstrated the utility of our method for the analysis of biological samples by applying it to the simultaneous quantitation of changes in soluble sugars and sugar phosphates in A. thaliana Columbia-0 (Col-0) and its starchless phosphoglucomutase (pgm) mutant over a 12-h light/12-h dark growth cycle.
Asunto(s)
Arabidopsis/química , Carbohidratos/análisis , Cromatografía Líquida de Alta Presión/instrumentación , Grafito/química , Espectrometría de Masa por Ionización de Electrospray/instrumentación , Fosfatos de Azúcar/análisis , Cromatografía Líquida de Alta Presión/métodos , Porosidad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masas en Tándem/métodosRESUMEN
Highly polar oligosaccharide analytes are notoriously difficult to separate by HPLC without prior derivatization or the use of highly alkaline eluent systems. Using a porous graphitic carbon (PGC) HPLC column, we have studied a pool of endogenous underivatized water-soluble oligosaccharides that were extracted from the stems of a range of wheat cultivars. The aqueous/organic eluents that are used with this stationary phase are ideal electrospray solvents and hence facilitate the on-line coupling of the analysis to mass spectrometry. Our on-line PGC-LC-MS method has allowed the separation of native oligosaccharides, dp 2-20, in under 30 min. The method is robust and suitable for the separation of other complex oligosaccharide mixtures. We propose that isomers of fructan structures are separated and that the branching in these structures can affect their elution order. Further, our findings on the size and type of oligosaccharides extracted from wheat stems have been compared to grain yield data. Cultivars known to be high in stem carbohydrate content have been shown to contain larger oligosaccharide structures than cultivars classified as low in stem carbohydrate content. Interestingly, the largest oligosaccharides were present in the stems of wheat plants harvested 14 days after flowering, which correlates directly with the time that grain filling occurs.
Asunto(s)
Carbono , Cromatografía Liquida/métodos , Espectrometría de Masas/métodos , Oligosacáridos/química , Tallos de la Planta/química , Triticum/química , Extractos Vegetales/químicaRESUMEN
Genista tenera is endemic to the Portuguese island of Madeira, where an infusion of the aerial parts of the plant is used in folk medicine as an antidiabetic agent. Consequently the medicinal properties of the secondary metabolites of this plant have been the subject of an ongoing study. A recently reported LC-MS method using a 100 min separation allowed identification of five flavonoid components in an extract of the aerial parts of this plant. In order to obtain additional information on the range and complexity of the plant's secondary metabolite components a CE-MS method has been developed and applied for the analysis of an extract of G. tenera. Twenty-six different components are distinguished in an analysis time of only 10 min. Results demonstrate that CE-MS/MS rapidly generates data complementary to those obtainable by LC-MS/MS and is particularly suited to the analysis of plant metabolites where concentration is not limiting.
Asunto(s)
Electroforesis Capilar/métodos , Genista/química , Hipolipemiantes/análisis , Espectrometría de Masas/métodos , Fenoles/análisis , Genista/metabolismoRESUMEN
Structures of three pectic arabinogalactans, one from Vernonia kotschyana (Vk2a) and two from Cochlospermum tinctorium (Ct50A1 and Ct50A2), and their complement fixation and induction of B cell proliferation in vitro were compared. The polysaccharide Vk2a expressed potent biological activity in both assays compared with Ct50A1 and Ct50A2. Vk2a possessed a very high molecular weight (1150 +/- 20 kDa) compared with Ct50A1 and Ct50A2 which both showed a polydisperse nature with the highest molecular weight polymers in each fraction estimated at approximately 105 kDa (Ct1a) and 640 +/- 100 kDa (Ct2a), respectively. The HMW polymers showed complement fixation in the same range as the native fractions. The arabinogalactan II content was low in Vk2a (2%) compared with that in Ct50A1 (23%) and Ct50A2 (12%). The high molecular weight polymers were subjected to digestion with a beta-d-(1, 3)-galactanase-rich fraction from Driselase, oligomers were isolated by HPAEC, and their finer structures were determined by MALDI- and ES-qoToF-MS, linkage, and monosaccharide composition analyses. Vk2a consists of both a galacturonan core and a rhamnogalacturonan core rich in neutral side chains. The backbones of both Ct-polysaccharides consist mainly of RG-I regions with numerous neutral side chains dominated by galactosyl residues, whereas the homogalacturonan regions seem to be small. Differences in the chain lengths of the 6-linked galacto-oligosaccharides attached to the 3-linked galactan core could not be related to the differences in the potencies of the biological activities observed.
Asunto(s)
Bixaceae/química , Proteínas del Sistema Complemento/efectos de los fármacos , Proteínas del Sistema Complemento/inmunología , Galactanos/química , Galactanos/farmacología , Mitógenos/farmacología , Vernonia/química , Aminoácidos/química , Animales , Antiulcerosos/química , Antiulcerosos/farmacología , Linfocitos B/citología , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Células Cultivadas , Pruebas de Fijación del Complemento , Femenino , Glicosilación , Espectroscopía de Resonancia Magnética , Ratones , Mitógenos/química , Mitosis/efectos de los fármacos , Peso Molecular , Monosacáridos/química , Océanos y Mares , Pectinas/química , Pectinas/farmacología , Relación Estructura-ActividadRESUMEN
The microsymbiont of alfalfa, Sinorhizobium meliloti, possesses phosphatidylglycerol, cardiolipin, phosphatidylethanolamine, and phosphatidylcholine as major membrane phospholipids, when grown in the presence of sufficient accessible phosphorus sources. Under phosphate-limiting conditions of growth, S. meliloti replaces its phospholipids by membrane lipids that do not contain any phosphorus in their molecular structure and, in S. meliloti, these phosphorus-free membrane lipids are sulphoquinovosyl diacylglycerols (SL), ornithine-containing lipids (OL), and diacylglyceryl-N,N,N-trimethylhomoserines (DGTS). In earlier work, we demonstrated that neither SL nor OL are required for establishing a nitrogen-fixing root nodule symbiosis with alfalfa. We now report the identification of the two structural genes btaA and btaB from S. meliloti required for DGTS biosynthesis. When the sinorhizobial btaA and btaB genes are expressed in Escherichia coli, they cause the formation of DGTS in this latter organism. A btaA-deficient mutant of S. meliloti is unable to form DGTS but can form nitrogen-fixing root nodules on alfalfa, demonstrating that sinorhizobial DGTS is not required for establishing a successful symbiosis with the host plant. Even a triple mutant of S. meliloti, unable to form any of the phosphorus-free membrane lipids SL, OL, or DGTS is equally competitive for nodule occupancy as the wild type. Only under growth-limiting concentrations of phosphate in culture media did mutants that could form neither OL nor DGTS grow to lesser cell densities.
Asunto(s)
Medicago sativa/microbiología , Lípidos de la Membrana/metabolismo , Fósforo/metabolismo , Sinorhizobium meliloti/crecimiento & desarrollo , Sinorhizobium meliloti/metabolismo , Secuencia de Bases , Medios de Cultivo , ADN Bacteriano/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Genes Bacterianos , Medicago sativa/metabolismo , Lípidos de la Membrana/química , Fijación del Nitrógeno , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Sinorhizobium meliloti/genética , Simbiosis/fisiologíaRESUMEN
Structure and immunological characteristics of the pectic arabinogalactan Vk2a (previously reported as Vk100A2a) from the roots of Vernonia kotschyana Sch. Bip. ex Walp. were investigated after enzymatic digestion of the galacturonan moiety and the side chains of the rhamnogalacturonan structure of Vk2a. endo-alpha-D-(1-->4)-Polygalacturonase digestion released the high molecular weight 'hairy region' (Vk2a-HR) and oligogalacturonides. Vk2a-HR consisted of GalA (4-linked) and Rha (2- or 2,4-linked) in a 1:1 ratio, with 60% of Rha branched at C-4. The Rha located in the rhamnogalacturonan core was branched randomly by Gal units. Vk2a-HR was rich in neutral sugars such as Araf 5- (12.2%) and 3,5-substituted (12.8%) and terminally- (14.1%) linked and Gal 4- (13.0%), 3- (0.9%), 6- (2.2%) and 3,6- (1.1%) substituted. Arabinans with chain lengths up to 11 units were identified. Araf residues were attached to C-3 of alpha-L-(1-->5)-Araf chains and to C-4 of Gal residues. Single Gal units and chains of beta-D-(1-->6)-linked galacto di- to penta-saccharides were attached to a beta-D-(1-->3)-galactan core. All the enzyme resistant fractions expressed potent complement fixation and induction of B-cell mitogenic activity, and the present study indicates that there may be several and possibly structurally different active sites involved in the bioactivity of Vk2a. The bioactive sites may be located both in the more peripheral parts of the molecule but also in the inner core of the 'hairy region' or in larger enzyme-resistant chains.