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1.
J AOAC Int ; 101(5): 1466-1472, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-29895350

RESUMEN

A single-laboratory validation of a method using Folin & Ciocalteu's phenol reagent (Folin-C reagent) for determination of total phenolic content of selected dietary supplement extracts was performed. The method is composed of a water extraction of dried extracts with sonication followed by reaction with the Folin-C reagent. The resulting colorimetric reaction is measured at 765 nm and compared with a standard curve generated with gallic acid standard solutions. The validation results were compared with Standard Method Performance Requirement (SMPR®) 2015.009, developed by the Stakeholder Panel on Dietary Supplements. The method demonstrated acceptable within-day RSDr of 1.96-7.47% for the five matrixes studied (grape seed extract, grape skin extract, black tea extract, green coffee extract, and cocoa extract). When gallic acid was spiked into maltodextrin (a surrogate dietary supplement carrier) at 30 or 70%, the recovery ranged from 91 to 104%, within the acceptable range established by SMPR 2015.009. Selectivity testing with glucose, fructose, and sucrose demonstrated no positive interference by these compounds. Finally, ruggedness studies demonstrated no significant effects due to changes in the heating apparatus, test material weight, read time after reaction, amount of Folin-C reagent, reaction time, reaction temperature, and amount of Na2CO3. The single-laboratory validation results support adoption of the method as First Action Official MethodSM 2017.13 and further evaluation in a collaborative study.


Asunto(s)
Colorimetría/métodos , Suplementos Dietéticos/análisis , Fenoles/análisis , Extractos Vegetales/análisis , Café/química , Extracto de Semillas de Uva/análisis , Indicadores y Reactivos , Sonicación/métodos , Té/química
2.
J AOAC Int ; 97(6): 1503-13, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25372663

RESUMEN

The most commonly used chondroitin sulfate (CS) assay method is cetylpyridinium chloride (CPC) titration. Cellulose acetate membrane electrophoresis (CAME) is the technique used for detection of impurities in the U.S. Pharmacopeia's CS monograph. Because CPC titration is a relatively nonspecific quantitative technique, the apparent amount of CS as determined by CPC titration alone may not reflect the true amount of CS due to possible interference with the CPC assay by impurities that contain CPC titratable functional groups. When CAME is used in conjunction with CPC titration, certain non-CS and adulterants can be visualized and estimated, and a true value for CS can be assigned once the presence of these non-CS impurities has been ruled out. This study examines conjunct application of CPC and CAME in ascertaining CS assay and purity in the presence of certain adulterants. These include propylene glycol alginate sulfate sodium, known in commerce as alginic sodium diester (ASD), and Zero One (Z1), a water-soluble agent newly reported in the CS marketplace and subsequently identified as sodium hexametaphosphate. ASD, Z1, and CS are similar in physical appearance and solubility in water and ethanol. They are also titratable anions and form ionic pairs with CPC, therefore interfering with the CPC titration assay for CS CAME separates these adulterants from each other and from CS by differences in their electrophoretic mobility. CAME is able to detect these impurities in CS at levels as low as 0.66% by weight. Although it is recommended that a method for detecting impurities (e.g., CAME) be used in cormbination with relatively nonspecific assay methods such as CPC titration, this is seldom done in practice. Assay results for CS derived fromn CPC titration may, therefore, be misleading, leaving the CS supply chain vulnerable to adulteration. In this study, the authors investigated ASD and Z1 adulteration of CS and developed an electrophoretic separation of these adulterants in CS and procedures to isolate ASD from CS matrixes containing these adulterants. The authors describe in this paper utilization of an orthogonal approach to establish the identity of Z1 as sodium hexametaphosphate and to confirm the identity of ASD, including ethanol fractionation, FTIR spectroscopy, differential scanning calorimetry, and NMR spectroscopy. The authors suggest that CAME is a cost-effective and easy to use methodfor detecting certain impurities in CS raw ingredients and recommend that CPC and CAME be used in combination by QC laboratories as a means of effectively deterring the practice of adulterating CS raw materials with the known adulterants ASD and Z1 and/or other non-chondroitin substances that can be separated from CSby CAME and that exhibit CPC titration behavior similar to CS.


Asunto(s)
Alginatos/aislamiento & purificación , Cetilpiridinio/química , Sulfatos de Condroitina/química , Electroforesis en Acetato de Celulosa/métodos , Fosfatos/aislamiento & purificación , Contaminación de Medicamentos , Ácido Glucurónico/aislamiento & purificación , Ácidos Hexurónicos/aislamiento & purificación , Volumetría
3.
J AOAC Int ; 97(2): 498-505, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24830162

RESUMEN

An international collaborative study was conducted of an HPLC-refractive index (RI) detector method for the determination of the combined amounts of sugars, glycerol, organic acids, and phenolic compounds in wines and wine-like beverages. Nine collaborating laboratories representing major winery, contract laboratories, and government laboratories tested eight different materials as blind duplicates using the proposed method. Sample materials included red and white wines, port, wine cooler, and nonalcoholic wine. One material was a negative control, and one material was a reference material. Samples were either treated with an ion-exchange resin to remove interfering organic acids prior to analysis or left untreated to include organic acids and phenolics. Red wine samples were treated with polyvinylpolypyrrolidone to remove potential interferences from phenolics prior to analysis. The HPLC analyses were performed on a Bio-Rad Fast Acid Analysis Column using RI detection. Reproducibility (RSD(R)) for untreated samples (sugars + phenolics + organic acids) ranged from 6.6% for Titrivin AA4 reference material to 11.0% for dry red wine. RSD(R) for treated samples (sugars only) ranged from 6.8% for white zinfandel to 18.9% for dry white wine. RSD(R) for treated samples (sugars only) + glycerol ranged from 6.4% for white zinfandel to 19.8% for dry red wine. Based on these results, the method was adopted as Official First Action status for determination of total carbohydrates in wine and wine-like beverages.


Asunto(s)
Carbohidratos/química , Cromatografía Líquida de Alta Presión/métodos , Análisis de los Alimentos/métodos , Vino/análisis , Refractometría
4.
J AOAC Int ; 96(5): 933-41, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24282928

RESUMEN

A rapid method has been developed to quantify seven catechins and caffeine in green tea (Camillia sinensis) raw material and powdered extract, and dietary supplements containing green tea extract. The method utilizes RP HPLC with a phenyl-based stationary phase and gradient elution. Detection is by UV absorbance. The total run time, including column re-equilibration, is 13 min. Single-laboratory validation (SLV) has been performed on the method to determine the repeatability, accuracy, selectivity, LOD, LOQ, ruggedness, and linearity for (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, (-)-epigallocatechin, (-)-gallocatechin gallate, (-)-epigallocatechin gallate, and (+)-gallocatechin, as well as caffeine. Repeatability precision and recovery results met AOAC guidelines for SLV studies for all catechins and caffeine down to a level of approximately 20 mg/g. Finished products containing high concentrations of minerals require the use of EDTA to prevent decomposition of the catechins.


Asunto(s)
Cafeína/análisis , Camellia sinensis/química , Catequina/análisis , Cromatografía Líquida de Alta Presión/métodos , Catequina/análogos & derivados , Reproducibilidad de los Resultados
5.
PLoS One ; 6(2): e14709, 2011 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-21379380

RESUMEN

BACKGROUND: Uridine is a therapy for hereditary orotic aciduria and is being investigated in other disorders caused by mitochondrial dysfunction, including toxicities resulting from treatment with nucleoside reverse transcriptase inhibitors in HIV. Historically, the use of uridine as a therapeutic agent has been limited by poor bioavailability. A food supplement containing nucleosides, NucleomaxX®, has been reported to raise plasma uridine to supraphysiologic levels. METHODOLOGY/PRINCIPAL FINDINGS: Single- and multi-dose PK studies following NucleomaxX® were compared to single-dose PK studies of equimolar doses of pure uridine in healthy human volunteers. Product analysis documented that more than 90% of the nucleoside component of NucleomaxX® is in the form of triacetyluridine (TAU). Single and repeated dosing with NucleomaxX® resulted in peak plasma uridine concentrations 1-2 hours later of 150.9 ± 39.3 µM and 161.4 ± 31.5 µM, respectively, levels known to ameliorate mitochondrial toxicity in vitro. C(max) and AUC were four-fold higher after a single dose of NucleomaxX® than after uridine. No adverse effects of either treatment were observed. CONCLUSIONS/SIGNIFICANCE: NucleomaxX®, containing predominantly TAU, has significantly greater bioavailability than pure uridine in human subjects and may be useful in the management of mitochondrial toxicity.


Asunto(s)
Suplementos Dietéticos , Uridina/análogos & derivados , Uridina/farmacocinética , Acetatos , Adulto , Disponibilidad Biológica , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Biológicos , Concentración Osmolar , Regulación hacia Arriba/efectos de los fármacos , Uridina/administración & dosificación , Uridina/sangre , Uridina/farmacología , Adulto Joven
6.
Fitoterapia ; 82(1): 44-52, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20884340

RESUMEN

Natural products chemistry is the discipline that lies at the heart of modern pharmacognosy. The field encompasses qualitative and quantitative analytical tools that range from spectroscopy and spectrometry to chromatography. Among other things, modern research on crude botanicals is engaged in the discovery of the phytochemical constituents necessary for therapeutic efficacy, including the synergistic effects of components of complex mixtures in the botanical matrix. In the phytomedicine field, these botanicals and their contained mixtures are considered the active pharmaceutical ingredient (API), and pharmacognosists are increasingly called upon to supplement their molecular discovery work by assisting in the development and utilization of analytical tools for assessing the quality and safety of these products. Unlike single-chemical entity APIs, botanical raw materials and their derived products are highly variable because their chemistry and morphology depend on the genotypic and phenotypic variation, geographical origin and weather exposure, harvesting practices, and processing conditions of the source material. Unless controlled, this inherent variability in the raw material stream can result in inconsistent finished products that are under-potent, over-potent, and/or contaminated. Over the decades, natural product chemists have routinely developed quantitative analytical methods for phytochemicals of interest. Quantitative methods for the determination of product quality bear the weight of regulatory scrutiny. These methods must be accurate, precise, and reproducible. Accordingly, this review discusses the principles of accuracy (relationship between experimental and true value), precision (distribution of data values), and reliability in the quantitation of phytochemicals in natural products.


Asunto(s)
Química Farmacéutica/normas , Medicina de Hierbas/métodos , Preparaciones de Plantas/normas , Química Farmacéutica/métodos , Estándares de Referencia , Reproducibilidad de los Resultados
7.
J AOAC Int ; 91(4): 702-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18727527

RESUMEN

An international collaborative study was conducted of a high-performance liquid chromatographic (HPLC)-UV method for the determination of coenzyme Q10 (CoQ10, ubidecarenone) in raw materials and dietary supplements. Ten collaborating laboratories determined the total CoQ10 content in 8 blind duplicate samples. Sample materials included CoQ10 raw material and 4 finished product dietary supplements representing softgels, hardshell gelatin capsules, and chewable wafers. In addition, collaborating laboratories received a negative control and negative control spiked with CoQ10 at low and high levels to determine recovery. Materials were extracted with an acetonitrile-tetrahydrofuran-water mixture. Ferric chloride was added to the test solutions to ensure all CoQ10 was in the oxidized form. The HPLC analyses were performed on a C18 column using UV detection at 275 nm. Repeatability relative standard deviations (RSDr) ranged from 0.94 to 5.05%. Reproducibility relative standard deviations (RSDR) ranged from 3.08 to 17.1%, with HorRat values ranging from 1.26 to 5.17. Recoveries ranged from 74.0 to 115%. Based on these results, the method is recommended for Official First Action for determination of CoQ10 in raw materials and dietary supplement finished products containing CoQ10 at a concentration of >100 mg CoQ10/g test material.


Asunto(s)
Suplementos Dietéticos/análisis , Ubiquinona/análogos & derivados , Calibración , Cápsulas/análisis , Cromatografía Líquida de Alta Presión , Estándares de Referencia , Reproducibilidad de los Resultados , Solventes , Espectrofotometría Ultravioleta , Comprimidos/análisis , Ubiquinona/análisis , Ubiquinona/química
8.
J AOAC Int ; 91(4): 694-701, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18727526

RESUMEN

A multilaboratory collaborative study was conducted on a high-performance liquid chromatographic (HPLC) method utilizing UV detection, previously validated using AOAC single-laboratory validation guidelines for determination of hydrastine and berberine in goldenseal (Hydrastis canadensis L.) raw materials, extracts, and dietary supplements at levels ranging from 0.4 to 6% (w/w). Nine collaborating laboratories determined the hydrastine and berberine content in 8 blind samples. Sample materials included powdered botanical raw materials, whole root material, and 4 finished product dietary supplements containing either goldenseal powdered root material or extract. The materials were extracted with an acidified water and acetonitrile solution. HPLC analyses of the extracts were performed on a C18 column using UV detection at 230 nm. Results for powdered root material and capsule products ranged from about 0.2% (w/w) for each alkaloid to about 4% (w/w) for each alkaloid. Liquid tincture results were approximately 4000-5000 microg/mL for each alkaloid. Reproducibility relative standard deviations (RSDR) for hydrastine ranged from 2.68 to 6.65%, with HorRat values ranging from 0.77 to 1.89. RSDR for berberine ranged from 5.66 to 7.68%, with HorRat values ranging from 1.32 to 2.12. All finished products containing goldenseal extract yielded HorRat values <2.0. Based on these results, the method is recommended for Official First Action for determination of hydrastine and berberine in goldenseal raw materials and dietary supplement finished products containing powdered goldenseal and goldenseal extract.


Asunto(s)
Bencilisoquinolinas/análisis , Berberina/análisis , Suplementos Dietéticos/análisis , Hydrastis/química , Cromatografía Líquida de Alta Presión , Extractos Vegetales/análisis , Raíces de Plantas/química , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrofotometría Ultravioleta
9.
J AOAC Int ; 90(5): 1227-36, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17955966

RESUMEN

A method based on high-performance liquid chromatography with ultraviolet detection has been developed to quantify ubidecarenone [coenzyme Q10 (CoQ10)] in raw materials and dietary supplements. Single-laboratory validation has been performed on the method to determine repeatability, accuracy, selectivity, limits of detection and quantification (LOQ), ruggedness, and linearity for CoQ10. As CoQ10 can exist as the biologically active reduced form, the application of an oxidizing agent, ferric chloride, drives the equilibrium mechanics to the fully oxidized state and allows for exact quantification of total CoQ10 in the sample. This method was found to be fit and linear for the testing of materials containing CoQ10 in the range of approximately equal 50-1000 mg/g. Repeatability precision for CoQ10 was between 2.15 and 5.00% relative standard deviation. Observed recovery of CoQ10 was found to be between 93.8 and 100.9%. LOQ was found to be 9 microg/mL. Further, limited studies showed that some adulterants and degraded material could be satisfactorily separated from CoQ10 and identified.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Espectrofotometría Ultravioleta/métodos , Ubiquinona/análogos & derivados , Técnicas de Química Analítica/métodos , Coenzimas/análisis , Coenzimas/química , Suplementos Dietéticos , Modelos Químicos , Oxidantes/química , Oxígeno/química , Reproducibilidad de los Resultados , Ubiquinona/análisis , Ubiquinona/química , Vitamina E/química , Vitamina K/química
10.
J AOAC Int ; 90(4): 934-40, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17760330

RESUMEN

The concentrations of caffeine and caffeine-related compounds in 2 ephedra-containing reference materials have been determined by 3 independent methods with measurements performed by the National Institute of Standards and Technology (NIST) and a collaborating laboratory. Results from the 3 methods were used for value assignment of caffeine, theobromine, and theophylline in these Standard Reference Materials (SRMs). The methods used at NIST to determine the concentration levels of caffeine, theobromine, and theophylline in SRM 3243 Ephedra-Containing Solid Oral Dosage Form and SRM 3244 Ephedra-Containing Protein Powder used reversed-phase liquid chromatography with absorbance detection and tandem mass spectrometry. These reference materials are part of the first suite in a series of NIST SRMs that provide concentration values for multiple components in dietary supplements. These SRMs are primarily intended for method validation and for use as control materials to support the analysis of dietary supplements and similar materials.


Asunto(s)
Cafeína/análisis , Técnicas de Química Analítica/métodos , Química Farmacéutica/métodos , Cromatografía Liquida/métodos , Ephedra/química , Espectrometría de Masas/métodos , Administración Oral , Cafeína/farmacología , Calibración , Cromatografía Líquida de Alta Presión , Suplementos Dietéticos/análisis , Polvos , Estándares de Referencia , Reproducibilidad de los Resultados , Teobromina/análisis , Teofilina/análisis
11.
J AOAC Int ; 90(3): 659-69, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17580617

RESUMEN

A method to quantify chondroitin sulfate in raw materials and dietary supplements at a range of about 5 to 100% (w/w) chondroitin sulfate has been developed and validated. The chondroitin sulfate is first selectively hydrolyzed by chondroitinase ACII enzyme to form un-, mono-, di-, and trisulfated unsaturated disaccharides; the resulting disaccharides are then quantified by ion-pairing liquid chromatography with ultraviolet detection. The amounts of the individual disaccharides are summed to yield the total amount of chondroitin sulfate in the material. Single-laboratory validation has been performed to determine the repeatability, accuracy, selectivity, limit of detection, limit of quantification, ruggedness, and linearity of the method. Repeatability precision for total chondroitin sulfate content was between 1.60 and 4.72% relative standard deviation, with HorRat values between 0.79 and 2.25. Chondroitin sulfate recovery from raw material negative control was between 101 and 102%, and recovery from finished product negative control was between 105 and 106%.


Asunto(s)
Técnicas de Química Analítica/métodos , Sulfatos de Condroitina/análisis , Cromatografía Líquida de Alta Presión/métodos , Suplementos Dietéticos/análisis , Enzimas/química , Animales , Bovinos , Disacáridos/análisis , Modelos Químicos , Estándares de Referencia , Reproducibilidad de los Resultados , Tiburones , Espectrofotometría Ultravioleta , Porcinos , Tráquea/metabolismo
12.
J AOAC Int ; 90(1): 68-81, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17373438

RESUMEN

A method has been developed to quantify synephrine in bitter orange raw material, extracts, and dietary supplements. Single-laboratory validation has been performed on the method to determine the repeatability, accuracy, selectivity, limit of detection/limit of quantification (LOQ), ruggedness, and linearity for p-synephrine and 5 other biogenic amines: octopamine, phenylephrine (m-synephrine), tyramine, N-methyltyramine, and hordenine, which may be present in bitter orange. p-Synephrine was found to be the primary biogenic amine present in all materials tested, accounting for >80% of the total biogenic amine content in all samples except a finished product. Repeatability precision for synephrine was between 1.48 and 3.55% RSD. Synephrine recovery was between 97.5 and 104%. The minor alkaloids were typically near the LOQ of the method (300-900 microg/g) in the test materials, and between-day precision for the minor compounds was poor because interferences could sometimes be mistakenly identified as one of the minor analytes. Recoveries of the minor components ranged from 99.1 to 103% at approximately 6000 microg/g spike level, to 90.7 to 120% at 300 microg/g spike level.


Asunto(s)
Aminas Biogénicas/análisis , Citrus/química , Suplementos Dietéticos/análisis , Extractos Vegetales/análisis , Sinefrina/análisis , Cromatografía Liquida/métodos , Reproducibilidad de los Resultados , Termodinámica , Rayos Ultravioleta
13.
BMC Musculoskelet Disord ; 7: 99, 2006 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-17156464

RESUMEN

BACKGROUND: Acupuncture is increasingly being used for many conditions including chronic neck pain. However the evidence remains inconclusive, indicating the need for further well-designed research. The aim of this study was to conduct a pilot randomised controlled parallel arm trial, to establish key features required for the design and implementation of a large-scale trial on acupuncture for chronic neck pain. METHODS: Patients whose GPs had diagnosed neck pain were recruited from one general practice, and randomised to receive usual GP care only, or acupuncture (up to 10 treatments over 3 months) as an adjunctive treatment to usual GP care. The primary outcome measure was the Northwick Park Neck Pain Questionnaire (NPQ) at 3 months. The primary analysis was to determine the sample size for the full scale study. RESULTS: Of the 227 patients with neck pain identified from the GP database, 28 (12.3%) consenting patients were eligible to participate in the pilot and 24 (10.5%) were recruited to the trial. Ten patients were randomised to acupuncture, receiving an average of eight treatments from one of four acupuncturists, and 14 were randomised to usual GP care alone. The sample size for the full scale trial was calculated from a clinically meaningful difference of 5% on the NPQ and, from this pilot, an adjusted standard deviation of 15.3%. Assuming 90% power at the 5% significance level, a sample size of 229 would be required in each arm in a large-scale trial when allowing for a loss to follow-up rate of 14%. In order to achieve this sample, one would need to identify patients from databases of GP practices with a total population of 230,000 patients, or approximately 15 GP practices roughly equal in size to the one involved in this study (i.e. 15,694 patients). CONCLUSION: This pilot study has allowed a number of recommendations to be made to facilitate the design of a large-scale trial, which in turn will help to clarify the existing evidence base on acupuncture for neck pain.


Asunto(s)
Terapia por Acupuntura , Dolor de Cuello/terapia , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Terapia por Acupuntura/métodos , Adulto , Anciano , Enfermedad Crónica , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Dolor de Cuello/epidemiología , Proyectos Piloto , Estudios Retrospectivos
14.
J AOAC Int ; 89(6): 1483-95, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17225593

RESUMEN

The National Institute of Standards and Technology, the U.S. Food and Drug Administration, Center for Drug Evaluation and Research and Center for Food Safety and Applied Nutrition, and the National Institutes of Health, Office of Dietary Supplements, are collaborating to produce a series of Standard Reference Materials (SRMs) for dietary supplements. A suite of ephedra materials is the first in the series, and this paper describes the acquisition, preparation, and value assignment of these materials: SRMs 3240 Ephedra sinica Stapf Aerial Parts, 3241 E. sinica Stapf Native Extract, 3242 E. sinica Stapf Commercial Extract, 3243 Ephedra-Containing Solid Oral Dosage Form, and 3244 Ephedra-Containing Protein Powder. Values are assigned for ephedrine alkaloids and toxic elements in all 5 materials. Values are assigned for other analytes (e.g., caffeine, nutrient elements, proximates, etc.) in some of the materials, as appropriate. Materials in this suite of SRMs are intended for use as primary control materials when values are assigned to in-house (secondary) control materials and for validation of analytical methods for the measurement of alkaloids, toxic elements, and, in the case of SRM 3244, nutrients in similar materials.


Asunto(s)
Ephedra/química , Alcaloides/análisis , Cadmio/análisis , Calcio/análisis , Carbohidratos/análisis , Suplementos Dietéticos/análisis , Ephedra/efectos de la radiación , Ácidos Grasos/análisis , Humedad , Estándares de Referencia , Reproducibilidad de los Resultados , Oligoelementos/análisis , Vitaminas/análisis
15.
Anal Chem ; 77(10): 3101-12, 2005 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-15889898

RESUMEN

A suite of five ephedra-containing dietary supplement Standard Reference Materials (SRMs) has been issued by the National Institute of Standards and Technology (NIST) with certified values for ephedrine alkaloids, synephrine, caffeine, and selected toxic trace elements. The materials represent a variety of natural, extracted, and processed sample matrixes that provide different analytical challenges. The constituents have been determined by multiple independent methods with measurements performed by NIST and by three collaborating laboratories. The methods utilized different sample extraction and cleanup steps in addition to different instrumental analytical techniques and approaches to quantification. In addition, food-matrix proximates were determined by National Food Processor Association laboratories for one of the ephedra-containing SRMs. The SRMs are primarily intended for method validation and for use as control materials to support the analysis of dietary supplements and related botanical materials.


Asunto(s)
Alcaloides/análisis , Suplementos Dietéticos/análisis , Efedrina/análisis , Análisis de los Alimentos , Cromatografía Liquida/métodos , Cromatografía Liquida/normas , Espectrometría de Masas/métodos , Espectrometría de Masas/normas , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
17.
J AOAC Int ; 87(1): 15-24, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15084082

RESUMEN

Ten collaborating laboratories determined the ephedra alkaloid content (ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, methylephedrine, and methylpseudoephedrine) in 8 blind duplicates of human plasma and urine using high-performance liquid chromatography (HPLC) with UV detection. In addition to negative urine and plasma controls, urine samples were spiked with individual ephedra alkaloids ranging in concentration from about 1 to 5 microg/mL. Plasma samples were spiked with individual ephedra alkaloids ranging in concentration from about 100 to 400 ng/mL. Sample solutions were treated to solid-phase extraction using a strong-cation exchange column to help remove interferences. The HPLC analyses were performed on a polar-embedded phenyl column using UV detection at 210 nm. The ephedra alkaloids were not consistently detected in any of the spiked plasma samples. When ephedra alkaloids were detected in the plasma samples, reproducibility between blind replicate samples was very poor. Repeatability, reproducibility, and accuracy were also very poor for the spiked urine samples. On the basis of these results, the HPLC-UV method for the determination of ephedra alkaloids in human urine and plasma is not recommended for adoption as Official First Action.


Asunto(s)
Estimulantes del Sistema Nervioso Central/orina , Efedrina/orina , Alcaloides/análisis , Calibración , Estimulantes del Sistema Nervioso Central/sangre , Cromatografía Líquida de Alta Presión , Efedrina/análogos & derivados , Efedrina/sangre , Humanos , Indicadores y Reactivos , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrofotometría Ultravioleta
18.
J AOAC Int ; 87(1): 1-14, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15084081

RESUMEN

An international collaborative study was conducted of a high-performance liquid chromatography (HPLC)-UV method for the determination of the major (ephedrine [EP] and pseudoephedrine [PS]) and minor (norephedrine [NE], norpseudoephedrine [NP], methylephedrine [ME], and methylpseudoephedrine [MP]) alkaloids in selected dietary supplements representative of the commercially available products. Ten collaborating laboratories determined the ephedrine-type alkaloid content in 8 blind replicate samples. Five products contained ephedra ground herb or ephedra extract. These 5 products included ground botanical raw material of Ephedra sinica, a common powdered extract of Ephedra sinica, a finished product containing only Ephedra sinica ground botanical raw material, a complex multicomponent dietary supplement containing Ma Huang, and a high-protein chocolate flavored drink mix containing Ma Huang extract. In addition, collaborating laboratories received a negative control and negative control spiked with ephedrine alkaloids at high and low levels for recovery studies. Test extracts were treated to solid-phase extraction using a strong-cation exchange column to help remove interferences. The HPLC analyses were performed on a polar-embedded phenyl column using UV detection at 210 nm. Repeatability relative standard deviations (RSDr) ranged from 0.64-3.0% for EP and 2.0-6.6% for PS, excluding the high protein drink mix. Reproducibility relative standard deviations (RSDR) ranged from 2.1-6.6% for EP and 9.0-11.4% for PS, excluding the high protein drink mix. Recoveries ranged from 84.7-87.2% for EP and 84.6-98.2% for PS. The data developed for the minor alkaloids are more variable with generally unsatisfactory HORRATS (i.e., >2). However, since these alkaloids generally add little to the total alkaloid content of the products, the method gives satisfactory results in measuring total alkaloid content (RSDr 0.85-3.13%; RSDR 2.03-10.97%, HORRAT 0.69-3.23, exclusive of the results from the high protein drink). On the basis of these results, the method is recommended for Official First Action for determination of EP and PS in dietary supplements exclusive of the high protein drinks.


Asunto(s)
Estimulantes del Sistema Nervioso Central/análisis , Suplementos Dietéticos/análisis , Efedrina/análisis , Alcaloides/análisis , Calibración , Cápsulas , Cromatografía Líquida de Alta Presión , Ephedra/química , Efedrina/análogos & derivados , Indicadores y Reactivos , Extractos Vegetales/análisis , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrofotometría Ultravioleta , Comprimidos
19.
Vaccine ; 20(23-24): 3023-33, 2002 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-12126916

RESUMEN

Respiratory syncytial virus (RSV) is an important cause of childhood respiratory disease as well as exacerbations of asthma. Although previous studies have demonstrated that a DNA vaccine encoding the RSV G protein can inhibit RSV replication in mouse models of RSV infection, studies have not been performed to determine whether a DNA vaccine encoding the RSV G protein can protect against RSV induced mucus expression and airway hyperresponsiveness which was the focus of this study. The DNA-G vaccine we constructed significantly inhibited RSV viral replication, mucus expression, and importantly was associated with inhibition of RSV induced airway responsiveness.


Asunto(s)
Virus Sincitiales Respiratorios/inmunología , Vacunas de ADN/farmacología , Proteínas Virales/inmunología , Vacunas Virales/farmacología , Animales , Anticuerpos Antivirales/sangre , Secuencia de Bases , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Femenino , Humanos , Inmunoglobulina G/sangre , Interleucina-13/metabolismo , Ratones , Ratones Endogámicos BALB C , Moco/fisiología , Plásmidos/genética , Hipersensibilidad Respiratoria/inmunología , Hipersensibilidad Respiratoria/prevención & control , Infecciones por Virus Sincitial Respiratorio/inmunología , Infecciones por Virus Sincitial Respiratorio/prevención & control , Virus Sincitiales Respiratorios/genética , Virus Sincitiales Respiratorios/patogenicidad , Vacunas de ADN/genética , Proteínas Virales/genética , Vacunas Virales/genética
20.
Am J Physiol Lung Cell Mol Physiol ; 282(2): L259-66, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11792630

RESUMEN

We have investigated the importance of cell-surface serine- and/or threonine-linked oligosaccharide adhesion molecules synthesized by the Golgi enzyme core 2 beta-1,6-N-acetylglucosaminyltransferase (C2GlcNAcT) in mediating eosinophil trafficking to the lung in studies utilizing C2GlcNAcT-I-deficient mice. The number of bronchoalveolar eosinophils, the number of lung eosinophils, and airway responsiveness to methacholine were not significantly different in C2GlcNAcT-I-deficient compared with wild-type mice sensitized and challenged by inhalation with ovalbumin. C2GlcNAcT-I-deficient mice do not demonstrate defects in neutrophil trafficking to the lung in response to lipopolysaccharide (LPS). In contrast, ragweed-sensitized C2GlcNAcT-I-deficient mice exhibit significantly reduced eosinophil trafficking to the peritoneal cavity in response to ragweed peritoneal challenge. C2GlcNAcT-I-deficient mice also have significantly reduced neutrophil trafficking to the peritoneal cavity in response to LPS challenge. Overall, these studies demonstrate an important role for serine/threonine-linked oligosaccharides synthesized by the Golgi enzyme C2GlcNAcT-I in eosinophil and neutrophil trafficking to the peritoneum but not for eosinophil or neutrophil trafficking to the lung.


Asunto(s)
Movimiento Celular/inmunología , Eosinófilos/citología , N-Acetilglucosaminiltransferasas/genética , Neutrófilos/citología , Oligosacáridos/metabolismo , Animales , Asma/inmunología , Asma/metabolismo , Médula Ósea/enzimología , Hiperreactividad Bronquial/inmunología , Hiperreactividad Bronquial/metabolismo , Broncoconstrictores/farmacología , Eosinófilos/enzimología , Femenino , Expresión Génica/inmunología , Aparato de Golgi/enzimología , Pulmón/citología , Pulmón/inmunología , Cloruro de Metacolina/farmacología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , N-Acetilglucosaminiltransferasas/metabolismo , Neutrófilos/enzimología , Peritoneo/citología , Peritoneo/inmunología , Peritonitis/inmunología , Peritonitis/metabolismo , Neumonía/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
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