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Medicinas Complementárias
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1.
Artículo en Inglés | MEDLINE | ID: mdl-36809736

RESUMEN

Alkaloids are natural bioactive ingredients but are usually present in low amounts in plant extracts. In addition, the dark color of plant extracts increases the difficulty in separation and identification of alkaloids. Therefore, effective decoloration and alkaloid enrichment methods are necessary for purification and further pharmacological studies of alkaloids. In this study, a simple and efficient strategy is developed for the decoloration and alkaloid enrichment of Dactylicapnos scandens (D. scandens) extracts. In feasibility experiments, we evaluated two anion-exchange resins and two cation-exchange silica-based materials with different functional groups using a standard mixture composed of alkaloids and nonalkaloids. By virtue of its high adsorbability of nonalkaloids, the strong anion-exchange resin PA408 is considered a better choice for the removal of nonalkaloids, and the strong cation-exchange silica-based material HSCX was selected for its great adsorption capacity for alkaloids. Furthermore, the optimized elution system was applied for the decoloration and alkaloid enrichment of D. scandens extracts. Nonalkaloid impurities in the extracts were removed by the use of PA408 in tandem with HSCX treatment, and the total alkaloid recovery, decoloration and impurity removal ratios are determined to be 98.74%, 81.45% and 87.33%, respectively. This strategy can contribute to further alkaloid purification and pharmacological profiling of D. scandens extracts, as well as other plants with medicinal value.


Asunto(s)
Alcaloides , Resinas de Intercambio Aniónico , Extractos Vegetales , Adsorción , Aniones
2.
Bioprocess Biosyst Eng ; 45(12): 2007-2017, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36352044

RESUMEN

Replacement of the petroleum-based refineries with the biorefinery is regarded as an essential step towards a "zero" waste (circular) economy. Biobased succinic acid (SA) is listed by the United States Department of Energy among the top ten chemicals with the potential to replace chemicals from petroleum synthesis with renewable sources. Purification of bio-based succinic acid from fermentation by-products such as alcohols, formic acid, acetic acid and lactic is a major drawback of fermentative SA production. This study addresses this issue through a novel chromatographic separation using three distinct anionic resins: Amberlite IRA958 Cl (strong base anion exchange resin), Amberlite HPR 900 OH (strong base anion exchange resin) and Amberlyst A21 (week base anion exchange resin). The influence of process variables such as flow rate (0.18 BV/h, 0.42 BV/h and 0.84 BV/h), eluent concentration (1%, 5% and 10% HCl) and temperature (20, 30 and 40 °C) were investigated. The results indicated SA separation efficiency of 76.1%, 69.3% and 81.2% for Amberlyst A21, Amberlite HPR 900 OH and Amberlite IRA958 Cl, respectively. As the regenerant HCl concentration increased from 1 to 10%, calculated succinic acid separation efficiencies decreased from 80.3 to 70.7%. Notably, as the regenerant strength increased from 1 to 10%, the total amount of organic acids desorbed from the resin sharply increased. At operation temperatures of 20, 30 and 40 °C, SA separation efficacies were 81.2%, 73.9% and 76.4%, respectively. The insights from this study will be of great value in design of chromatographic separation systems for organic acids.


Asunto(s)
Resinas de Intercambio Aniónico , Petróleo , Resinas de Intercambio Aniónico/química , Fermentación , Ácido Succínico/química , Suero Lácteo
3.
Artículo en Inglés | MEDLINE | ID: mdl-36252384

RESUMEN

Commercially available, strongly basic anion-exchange resins with quaternary ammonium groups have been widely used in the purification of natural plant extracts. However, under the condition of high temperature (greater than 60 °C), these resins could not be used for long periods because of the Hofmann degradation of the strongly basic groups. In this work, the synthesis of novel, thermally stable, strongly basic resins, which has a cross-link biguanide structure, was reported. The mechanism of thermal degradation was investigated, and the result indicated that not only the stability of the functional group but also the link mode between the functional group and the resin matrix should influence the thermal stability of the resin. In our experiment, the PDG2 resin was selected to separate sodium copper chlorophyllin (SCC), a type of edible pigment derived from plants, due to its optimal thermal stability and adsorption capacity. The adsorption mechanism and thermodynamics of PDG2 were also investigated. The results demonstrated that the main adsorption affinity of PDG2 toward SCC was due to the synergistic effects of the hydrophobic and ionic interactions, and the rise in temperature will benefit the adsorption equilibrium, which differed from the equilibrium for lutein. Therefore, under suitable gradient desorption conditions, a high-purity SCC extract was prepared. After eight cycles, the adsorption capacity of the PDG2 remained constant and reproducible at a high temperature (70 °C).


Asunto(s)
Resinas de Intercambio Aniónico , Clorofilidas , Resinas de Intercambio Aniónico/química , Biguanidas , Adsorción , Aniones
4.
Chemosphere ; 286(Pt 1): 131581, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34325265

RESUMEN

Adsorption represents one of the most promising process for phosphorous (P) removal and recovery from municipal wastewater, but questions about its long-term stability remain. The goals of this work were (i) to assess changes in morphology and adsorption performances of hybrid anion exchanger (HAIX) LayneRT after 2.5 years of operation in a 10 m3 d-1 demonstration plant fed with secondary-treated municipal wastewater, (ii) to optimize the LayneRT regeneration procedure, and (iii) to evaluate the suitability of the ion exchange model to describe P adsorption on LayneRT. LayneRT is composed of hydrated ferric nanoparticles dispersed in a strong base anion exchange resin. Batch and continuous flow adsorption/desorption tests were conducted with the resin used for 2.5 years, regenerated with two alternative solutions: NaOH, reactivating mainly the iron nanoparticles active sites, and NaOH + NaCl, also regenerating the active sites of the ion exchange media. The physicochemical characterization by Scanning Electron Microscope indicated that regeneration by NaOH significantly reduced the deterioration of the resin surface, even after 59 adsorption/desorption cycles. Lab-scale continuous flow tests showed that the resin regenerated with either solution featured P adsorption performances very close to that of the virgin resin. The isotherm tests showed that P adsorption by LayneRT was effectively simulated with the ion exchange model. This study confirms that LayneRT is a durable, resistant and promising media for P recovery from wastewater.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Resinas de Intercambio Aniónico , Intercambio Iónico , Resinas de Intercambio Iónico , Cinética , Fósforo , Aguas Residuales , Contaminantes Químicos del Agua/análisis
5.
Anal Sci ; 37(12): 1789-1794, 2021 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-34305053

RESUMEN

We present a resin-packed microchannel that can reduce the radiation exposure risk and secondary radioactive wastes during uranium (U) separation by downscaling the separation using a microchip. Two types of microchips were designed to densely pack the microchannels with resins. The microchannels had almost the same cross-sectional area, but different outer circumferences. A satisfactory separation performance could be obtained by arranging more than ca. 10 resins along the depth and width of the microchannels. A resin-packed microchannel is an effective separation technique for determining the U concentration via inductively coupled plasma mass spectrometry owing to its ability to avoid the contamination of equipment by cesium, and to reduce the matrix effect. The size of the separation site was scaled down to <1/5000 compared to commonly used counterparts. The radiation exposure risk and secondary radioactive wastes can be reduced by 10- and 800-fold, respectively, using a resin-packed microchannel.


Asunto(s)
Uranio , Resinas de Intercambio Aniónico , Cesio , Agua de Mar , Uranio/análisis
6.
J Hazard Mater ; 420: 126582, 2021 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-34274802

RESUMEN

This study shows the technical feasibility to recover uranium from copper Pregnant Leaching Solutions (PLS) using ion-exchange, after a removal of chloride ions using the electrodialysis (ED) technique. The original copper PLS solutions came from the National Copper Corporation (CODELCO), from their hydrometallurgical operations, which contained high concentrations of chloride ions. These solutions contained average concentrations of 22 g/L chloride ions, pH 1.5 - 1.8 and 20 mg/L uranium. The high chloride contents made the uranium recovery technically unfeasible, because of the high volumes of chemical reagents needed to operate. To eliminate the chloride ions selectively, a modified electrodialysis (ED) process was developed. The ED process was made of a three-compartment cell. This system removed selectively the chloride ions, and replaced them with sulphuric ions, without modifying the composition of the copper PLS solution, to allow a continuous operation of the copper production plant. The ED process decreased the chloride content from 22 g/L to 6 g/L. Finally, static and dynamic load tests were performed for both the original PLS and the treated PLS, using 3 different anion-exchange resins: Dowex-1, Lewatit A365 and Lewatit MP62-WS. The loading capacity of the ion-exchange resins was increased 4 times approximately.


Asunto(s)
Uranio , Resinas de Intercambio Aniónico , Cloruros , Cobre , Concentración de Iones de Hidrógeno , Intercambio Iónico
7.
Methods Mol Biol ; 2295: 365-378, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34047987

RESUMEN

The phosphate esters of myo-inositol (Ins) occur ubiquitously in biology. These molecules exist as soluble or membrane-resident derivatives and regulate a plethora of cellular functions including phosphate homeostasis, DNA repair, vesicle trafficking, metabolism, cell polarity, tip-directed growth, and membrane morphogenesis. Phosphorylation of all inositol hydroxyl groups generates phytic acid (InsP6), the most abundant inositol phosphate present in eukaryotic cells. However, phytic acid is not the most highly phosphorylated naturally occurring inositol phosphate. Specialized small molecule kinases catalyze the formation of the so-called myo-inositol pyrophosphates (PP-InsPs), such as InsP7 and InsP8. These molecules are characterized by one or several "high-energy" diphosphate moieties and are ubiquitous in eukaryotic cells. In plants, PP-InsPs play critical roles in immune responses and nutrient sensing. The detection of inositol derivatives in plants is challenging. This is particularly the case for inositol pyrophosphates because diphospho bonds are labile in plant cell extracts due to high amounts of acid phosphatase activity. We present two steady-state inositol labeling-based techniques coupled with strong anion exchange (SAX)-HPLC analyses that allow robust detection and quantification of soluble and membrane-resident inositol polyphosphates in plant extracts. These techniques will be instrumental to uncover the cellular and physiological processes controlled by these intriguing regulatory molecules in plants.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Fosfatos de Inositol/química , Resinas de Intercambio Aniónico/química , Aniones/química , Arabidopsis/metabolismo , Proteínas de Arabidopsis/aislamiento & purificación , Proteínas de Arabidopsis/metabolismo , Inositol/química , Fosfatos de Inositol/metabolismo , Fosfatidilinositoles/química , Fosforilación , Plantas/química , Plantas/metabolismo , Polifosfatos/química , Semillas/química , Transducción de Señal/fisiología
8.
Environ Sci Pollut Res Int ; 27(20): 24863-24878, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32307687

RESUMEN

Ca(NO3)2 addition has proved to have a high potential to immobilize internal phosphorus (P) in sediments; however, it cannot effectively stop the release of ammonium-nitrogen (NH4+-N) from sediments into overlying waters (OL-waters). Additionally, the addition of Ca(NO3)2 alone has high risk of nitrate-nitrogen (NO3--N) releasing into OL-waters. To overcome the shortcoming of the Ca(NO3)2 addition method, we reported an integrated method, i.e., a combined method based on Ca(NO3)2 injection, zeolite capping, and anion exchange resin (AERN)-contained floating system suspending (Ca(NO3)2/zeolite/AERN). The effectiveness and mechanism of the Ca(NO3)2/zeolite/AERN method for simultaneously controlling the release of soluble reactive P (SRP) and NH4+-N were investigated, and the NO3--N releasing risk of this method was evaluated. It was found that the joint use of Ca(NO3)2 injection, zeolite capping, and AERN-contained floating system suspending not only could effectively suppress the release of SRP and NH4+-N from sediments into OL-waters simultaneously, but also had much less risk of NO3--N releasing into OL-waters as compared to the single Ca(NO3)2 injection method and the combined Ca(NO3)2/zeolite method. The inhibition of the reductive dissolution of the P-bound Fe(III) oxides/hydroxides by the presence of nitrate and the adsorption of ammonium on the zeolite played very important roles in the interception of SRP and NH4+-N releasing into OL-waters by the Ca(NO3)2/zeolite/AERN method. After the sediment remediation using the Ca(NO3)2/zeolite/AERN approach, the increase in the content of residual P in the sediment layer of 0-50 mm, the decrease of mobile P in the sediment layer of 0-10 mm, and the increased NH4+-N adsorption capacity for the sediment layer of 0-10 mm would be conductive to the interception of SRP and NH4+-N liberation in the long run. Results of this research suggest a promising application potential of the Ca(NO3)2/zeolite/AERN method in the simultaneous control of the release of SRP and NH4+-N from sediments.


Asunto(s)
Contaminantes Químicos del Agua/análisis , Zeolitas , Resinas de Intercambio Aniónico , Compuestos de Calcio , Compuestos Férricos , Sedimentos Geológicos , Nitratos , Nitrógeno/análisis , Fósforo
9.
Anal Bioanal Chem ; 411(14): 3103-3113, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30972471

RESUMEN

13C metabolite tracer and metabolic flux analyses require upfront experimental planning and validation tools. Here, we present a validation scheme including a comparison of different LC methods that allow for customization of analytical strategies for tracer studies with regard to the targeted metabolites. As the measurement of significant changes in labeling patterns depends on the spectral accuracy, we investigate this aspect comprehensively for high-resolution orbitrap mass spectrometry combined with reversed-phase chromatography, hydrophilic interaction liquid chromatography, or anion-exchange chromatography. Moreover, we propose a quality control protocol based on (1) a metabolite containing selenium to assess the instrument performance and on (2) in vivo synthesized isotopically enriched Pichia pastoris to validate the accuracy of carbon isotopologue distributions (CIDs), in this case considering each isotopologue of a targeted metabolite panel. Finally, validation involved a thorough assessment of procedural blanks and matrix interferences. We compared the analytical figures of merit regarding CID determination for over 40 metabolites between the three methods. Excellent precisions of less than 1% and trueness bias as small as 0.01-1% were found for the majority of compounds, whereas the CID determination of a small fraction was affected by contaminants. For most compounds, changes of labeling pattern as low as 1% could be measured. Graphical abstract.


Asunto(s)
Isótopos de Carbono/análisis , Cromatografía por Intercambio Iónico/métodos , Cromatografía de Fase Inversa/métodos , Espectrometría de Masas/métodos , Estudios de Validación como Asunto , Resinas de Intercambio Aniónico/química , Isótopos de Carbono/normas , Interacciones Hidrofóbicas e Hidrofílicas , Pichia/química , Estándares de Referencia , Selenio/química
10.
Environ Sci Pollut Res Int ; 26(33): 34233-34247, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30617880

RESUMEN

Removal and recovery of phosphorus (P) from sewage are essential for sustainable development of P resource. Based on the water quality determination of sludge dewatering filtrate from a wastewater treatment plant in Beijing, this study investigated the adsorption and regeneration characteristics of P by magnetic anion exchange resin (MAEX). The experiments showed that the P adsorption capacity of MAEX could reach a maximum of 2.74 mg/mL when initial P concentration was 25 mg/L and dosage of MAEX was 8 mL/L. The P adsorption on MAEX resin was suitable for large temperature range (283-323 K). However, the adsorption capacity was reduced in various degrees due to the interference of different anions (Br-, SO42-, Cl-, NO3-, HCO3-, CO32-) and organic compounds (bovine serum albumin, humic acid). Kinetics studies indicated that the P adsorption process followed the pseudo-second-order model. The MAEX resin had a rapid P adsorption rate and the P adsorption capacity at 30 min could reach 97.7-99.3% of qe. Increase of temperature was favorable to P adsorption on MAEX, and the adsorption isotherm data fitted to Langmuir model more than Freundlich model. Meanwhile, the thermodynamics parameters were calculated; it was shown that the adsorption process was an endothermic reaction. Desorption and regeneration experiments showed that NaHCO3 was a suitable regenerant, and the P adsorption capacity could reach 90.51% of the original capacity after 10 times of adsorption-desorption cycles; this indicated that MAEX resin has an excellent regeneration performance and thus has a very good application prospect of P removal and recovery. Fourier transform infrared spectroscopy (FTIR) analysis confirmed that ion exchange, charge attraction, and hydrogen bonding affected the removal of P by the MAEX resin. The vibrating sample magnetometer (VSM) analysis revealed that MAEX resin was a kind of soft magnetic materials with good magnetism.


Asunto(s)
Resinas de Intercambio Aniónico/química , Fósforo/análisis , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/análisis , Adsorción , Aniones , Beijing , Sustancias Húmicas , Concentración de Iones de Hidrógeno , Intercambio Iónico , Cinética , Fenómenos Magnéticos , Magnetismo , Aguas del Alcantarillado , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Termodinámica , Aguas Residuales
11.
Anal Sci ; 35(3): 347-350, 2019 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-30344207

RESUMEN

We propose the creation of reusable indicator-sorbed-solids, using anion-exchange resins or kaolin as supports, with the aim to reduce chemical use towards green analytical chemistry. Indicators (phenolphthalein, thymol blue and butterfly pea flower extract as a natural indicator) sorbed on a solid support, were employed in acid-base titration, in both homogenous aqueous and heterogenous aqueous organic phases. Applications of the developed techniques to some real samples, such as vinegar, colored fruit juice and vegetable oil, have been demonstrated.


Asunto(s)
Resinas de Intercambio Aniónico/química , Análisis de los Alimentos/métodos , Tecnología Química Verde/métodos , Indicadores y Reactivos/química , Caolín/química , Volumetría/métodos , Ácido Acético/análisis , Adsorción , Jugos de Frutas y Vegetales/análisis , Aceites de Plantas/análisis
12.
J Chromatogr A ; 1517: 35-43, 2017 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-28859891

RESUMEN

The present work presents a novel and rapid analytical method for the simultaneous analysis of bisphenol A (BPA), bisphenol B (BPB), bisphenol F (BPF) and bisphenol S (BPS) in edible oil based on dispersive micro solid phase extraction (DMSPE) for the first time followed by isotope dilution-ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The edible oil sample was dispersed by n-hexane and extracted with ammoniated methanol-water solution. Then the target analytes were dispersedly absorbed using the polymer anion exchange (PAX) as the sorbent and eluted by acidic methanol. After that, four bisphenols were separated on a C18 column by gradient elution with methanol and 0.05% ammonium hydroxide in water as mobile phase, detected by MS/MS under multiple reactions monitoring (MRM) mode and quantified by internal standard method. The PAX amounts, adsorption time, concentrations of formic acid in the elution solvent and volume of elution solvent for the DMSPE technique were optimized. The limit of detection and quantitation (LOD and LOQ), matrix effect, recovery and precision of the developed method were investigated. Results indicated that BPS and the rest three bisphenols displayed excellent linearity in the concentration ranges of 0.1-50µg/L and 0.5-250µg/L, respectively, with correlation coefficients (R2) all larger than 0.998. Achieved MLODs (S/N=3) varied between 0.1-0.4µg/kg for all bisphenols. The mean recoveries at three spiked levels in edible oil were in the range of 87.3-108%. Intra-day precision (n=6) and inter-day precision (n=5) were <9% and <11%, respectively. This method is of rapid-and-simple pretreatment, accurate and sensitive, and suitable for the simultaneous determination of bisphenols in edible oil.


Asunto(s)
Compuestos de Bencidrilo/análisis , Grasas Insaturadas en la Dieta/análisis , Análisis de los Alimentos/métodos , Polímeros/química , Extracción en Fase Sólida , Adsorción , Resinas de Intercambio Aniónico/química , Hexanos/química , Límite de Detección , Fenoles/análisis , Aceites de Plantas/química , Sulfonas/análisis , Espectrometría de Masas en Tándem
13.
Chemosphere ; 172: 111-119, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28063313

RESUMEN

Selenium (Se) removal from synthetic solutions and from real Flue Gas Desulfurization (FGD) wastewater generated by a coal-fired power plant was studied for the first time using a commercial iron oxide impregnated strong base anion exchange resin, Purolite® FerrIX A33E. In synthetic solutions, the resin showed high affinity for selenate and selenite, while sulfate exhibited a strong competition for both oxyanions. The FGD wastewater investigated is a complex system that contains Se (∼1200 µg L-1), SO42- (∼1.1 g L-1), Cl- (∼9.5 g L-1), and Ca2+ (∼5 g L-1), alongside a broad spectrum of toxic trace metals including Cd, Cr, Hg, Ni, and Zn. The resin performed poorly against Se in the raw FGD wastewater and showed moderate to good removal of several trace elements such as Cd, Cr, Hg, and Zn. In FGD effluent, sulfate was identified as a powerful competing anion for Se, having high affinity for the exchange active sites of the resin. The desulfurization of the FGD effluent using BaCl2 led to the increase in Se removal from 3% (non-desulfurized effluent) to 80% (desulfurized effluent) by combined precipitation and ion exchange treatment. However, complete desulfurization using equimolar BaCl2 could not be achieved due to the presence of bicarbonate that acts as a sulfate competitor for barium. In addition to selenium and sulfate removal, several toxic metals were efficiently removed (Cd: 91%; Cr: 100%; Zn: 99%) by the combined (desulfurization and ion exchange) treatment.


Asunto(s)
Resinas de Intercambio Aniónico/química , Compuestos Férricos/química , Selenio/análisis , Sulfatos/análisis , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Compuestos de Bario/química , Cloruros/química , Metales Pesados/análisis , Centrales Eléctricas , Oligoelementos/análisis , Aguas Residuales/química
14.
Food Chem ; 217: 461-468, 2017 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-27664659

RESUMEN

An efficient decoloration method for polysaccharides from the sprouts of Toona sinensis (A. Juss.) Roem (PSTS) by anion exchange macroporous resins (AEMR) was investigated in the present paper. The results suggested that D941 resin offered better decoloration efficiency than other tested resins. Based on single-factor experiments, the optimal decoloration parameters of D941 resin were obtained as follows: temperature of 45°C, sample initial concentration of 30mg/ml, pH value of 8.5, static decoloration time of 90min, dynamic decoloration processing volume of 5.5BV with the flow rate of 2BV/h. Decoloration ratio, PSTS recovery ratio and selectivity coefficient were 91.94±1.23%, 90.05±2.35% and 10.92±0.63, respectively. Most of pigment impurities were successfully removed from PSTS solutions after treated by D941 resin, and there was no significant difference in carbohydrate concentration, characteristic groups and molecular weight. Compared with H2O2 oxidation and activated carbon adsorption, this developed method is superior.


Asunto(s)
Resinas de Intercambio Aniónico/química , Meliaceae , Pigmentos Biológicos/análisis , Extractos Vegetales/análisis , Polisacáridos/análisis , Plantones/química , Adsorción
15.
J Chromatogr A ; 1466: 37-41, 2016 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-27614730

RESUMEN

To separate thorium and uranium in nitric acid solution using anion exchange process, a strong base silica-based anion exchange resin (SiPyR-N4) was synthesized. Batch experiments were conducted and the separation factor of thorium and uranium in 9M nitric acid was about 10. Ion exchange chromatography was applied to separate thorium and uranium in different ratios. Uranium could be eluted by 9M nitric acid and thorium was eluted by 0.1M nitric acid. It was proved that thorium and uranium can be separated and recovered successfully by this method.


Asunto(s)
Resinas de Intercambio Aniónico/química , Cromatografía por Intercambio Iónico/métodos , Dióxido de Silicio/química , Torio/aislamiento & purificación , Uranio/aislamiento & purificación , Cromatografía por Intercambio Iónico/instrumentación , Ácido Nítrico/química , Torio/química , Uranio/química
16.
Curr Probl Dermatol ; 50: 142-8, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27578083

RESUMEN

Cholestatic itch is a feature of numerous hepatobiliary disorders such as primary biliary cirrhosis, primary sclerosing cholangitis, the inherited form of cholestasis, and intrahepatic cholestasis of pregnancy. Although undervalued by physicians, cholestatic itch can be a source of great discomfort to the patient and significantly affects quality of life. Many pruritogens such as bile salts, opioids, serotonin, and histamine have been implicated in the pathogenesis of cholestatic itch, but no causative link has ever been established. Recent findings indicate that the potent neuronal activator lysophosphatidic acid and autotaxin, the enzyme forming lysophosphatidic acid, may be key elements in its pathogenesis. Treatment options for patients with cholestatic itch include the anion exchange resin cholestyramine, bile acid ursodeoxycholic acid, PXR agonist rifampicin, opioid antagonist naltrexone, and the serotonin inhibitor sertraline. These drugs can be used as a stepwise therapeutic approach. The body of evidence for many of these options, however, is not very robust. Patients who do not respond to medical therapy can be candidates for interventional measures, such as albumin dialysis, plasmapheresis, or nasobiliary drainage, or certain experimental approaches such as UVB phototherapy. Research over the past decade has elucidated many of the receptors and neuropeptides involved in itch sensation and transmission; it is hoped that in the future this will lead to the development of novel antipruritic medication for cholestatic itch.


Asunto(s)
Resinas de Intercambio Aniónico/uso terapéutico , Colagogos y Coleréticos/uso terapéutico , Colestasis/terapia , Antagonistas de Narcóticos/uso terapéutico , Prurito/terapia , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Terapia Ultravioleta , Colestasis/complicaciones , Colestasis/metabolismo , Resina de Colestiramina/uso terapéutico , Humanos , Lisofosfolípidos/metabolismo , Naltrexona/uso terapéutico , Plasmaféresis , Receptor X de Pregnano , Prurito/etiología , Receptores de Esteroides/agonistas , Rifampin/uso terapéutico , Sertralina/uso terapéutico , Ácido Ursodesoxicólico/uso terapéutico
17.
Int J Food Sci Nutr ; 67(4): 454-60, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27019314

RESUMEN

Commercial preparations of 6-phytase A alone and in combination with phytase B were used in rye breadmaking. Determination of bioavailability of myo-inositol phosphates from bread was performed by an in vitro digestion method followed by the measurement of an uptake by Caco-2 cells in culture. In bread supplemented with a combination of 6-phytase A and phytase B, a significant reduction in phytate content was observed from 3.62 µmol/g in the control to 0.7 µmol/g. Bioavailability of phytate estimated by an in vitro method simulating digestion in the human alimentary tract was 9% in the bread supplemented with phytase B, 7% (6-phytase A) and 50% in the control bread. In cell culture, the bioaccessibilities of inositol triphosphates from bread baked with the addition of 6-phytase A was higher by 36% as compared to the samples baked with phytase B and by 32% in breads baked with combination of both phytases.


Asunto(s)
6-Fitasa/metabolismo , Pan/análisis , Fibras de la Dieta/metabolismo , Aditivos Alimentarios/metabolismo , Fosfatos de Inositol/metabolismo , Absorción Intestinal , Secale/química , Resinas de Intercambio Aniónico , Células CACO-2 , Cromatografía Líquida de Alta Presión , Fibras de la Dieta/análisis , Digestión , Harina/análisis , Humanos , Inositol 1,4,5-Trifosfato/análisis , Inositol 1,4,5-Trifosfato/metabolismo , Fosfatos de Inositol/análisis , Isoenzimas , Modelos Biológicos , Valor Nutritivo , Fosforilación , Ácido Fítico/análisis , Ácido Fítico/metabolismo , Polonia
18.
J Pharm Biomed Anal ; 119: 91-8, 2016 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-26669613

RESUMEN

The analysis of trace constituents in herbal medicines has always been a challenge due to complex matrices and structural diversities. In this work, a pH-sensitive solid phase extraction (SPE) procedure capable of enriching trace polyphenols in Bistort Rhizoma (BR) was proposed and preliminary chemical characterization was accomplished by high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF MS). A weak anion-exchange SPE column packed with divinylbenzene/vinylpyrrolidone bonding quaternary amine group was employed for anionic extraction, and the target fraction was obtained by eluting with acidic methanol (apparent pH 1.9). On the other hand, the MS/MS fragmentation rules of four reference polyphenols in negative ion mode were outlined. Using these rules, a total of 31 polyphenols including 20 benzoyl derivatives and 11 caffeoyl derivatives were screened out from BR extract, of which 26 trace members were found for the first time in this herb. Those findings demonstrated that the anion-exchange SPE could enhance the detection capability and selectivity for plant polyphenols in the LC-MS analysis and the strategy for deducing structures could be applied for analysis of polyphenols in BR and other herbal medicines.


Asunto(s)
Resinas de Intercambio Aniónico/química , Medicamentos Herbarios Chinos/química , Polygonum/química , Polifenoles/análisis , Rizoma/química , Cromatografía Líquida de Alta Presión/métodos , Espectrometría de Masas/métodos , Estructura Molecular , Polifenoles/química , Extracción en Fase Sólida/métodos
19.
Bioresour Technol ; 201: 365-9, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26644321

RESUMEN

Membrane adsorption hybrid system (MAHS) was evaluated for the removal of phosphate from a high rate membrane bioreactor (HR-MBR) effluent. The HR-MBR was operated at permeate flux of 30L/m(2)h. The results indicated that the HR-MBR could eliminate 93.1±1.5% of DOC while removing less than 53% phosphate (PO4-P). Due to low phosphate removal by HR-MBR, a post-treatment of strong base anion exchange resin (Dowex(∗)21K-XLT), and zirconium (IV) hydroxide were used as adsorbent in MAHS for further removal of phosphate from HR-MBR effluent. It was found that the MAHS enabled to eliminate more than 85% of PO4-P from HR-MBR effluent. Hence, HR-MBR followed by MAHS lead to simultaneous removal of organics and phosphate in a reliable manner. The experiments were conducted only for a short period to investigate the efficiency of these resins/adsorbents on the removal of phosphorus and high rate MBR for organic removal.


Asunto(s)
Membranas Artificiales , Fósforo/aislamiento & purificación , Adsorción , Resinas de Intercambio Aniónico , Biomasa , Reactores Biológicos , Costos y Análisis de Costo , Compuestos Orgánicos/aislamiento & purificación , Fosfatos/aislamiento & purificación
20.
Molecules ; 20(12): 22422-34, 2015 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-26694329

RESUMEN

Residual enzymatic activity in certain foods, particularly of polyphenoloxidase (PPO), is responsible for the majority of anthocyanin degradation in food systems, causing also parallel losses of other relevant nutrients. The present work explored the feasibility of modifying phenolic profiles of thyme extracts, by use of chromatographic resins, to obtain phenolic extracts capable of enhancing anthocyanin colour and stability in the presence of PPO activity. Results indicated that pretreatment of thyme extracts with strong-anion exchange resins (SAE) enhanced their copigmentation abilities with strawberry juice anthocyanins. Phenolic chromatographic profiles, by HPLC-PDA, also demonstrated that thyme extracts subjected to SAE treatments had significantly lower concentrations of certain phenolic compounds, but extracts retained their colour enhancing and anthocyanin stabilization capacities though copigmentation. Additional testing also indicated that SAE modified extract had a lower ability (73% decrease) to serve as PPO substrate, when compared to the unmodified extract. Phenolic profile modification process, reported herein, could be potentially used to manufacture modified anthocyanin-copigmentation food and cosmetic additives for colour-stabilizing applications with lower secondary degradation reactions in matrixes that contain PPO activity.


Asunto(s)
Antocianinas/química , Antioxidantes/química , Bebidas/análisis , Catecol Oxidasa/antagonistas & inhibidores , Fragaria/química , Thymus (Planta)/química , Resinas de Intercambio Aniónico/química , Antioxidantes/aislamiento & purificación , Color , Conservación de Alimentos/métodos , Humanos , Oxidación-Reducción , Fenoles/química , Extractos Vegetales/química
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