Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
1.
Pak J Pharm Sci ; 34(4(Supplementary)): 1549-1554, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34799331

RESUMEN

Ephedra, natural flora has been used traditionally to treat rheumatism since decades. The scientific evidence of anti-rheumatic effect of this plant has also been reported. But the anti-rheumatic activity of major constituent of this plant (ephedrine) has not been evaluated. Based on this, the current study was aimed to assess anti-arthritic activity of ephedrine by using in vitro and in vivo approaches. Correspondingly, enzyme linked immunosorbent assay was performed for the estimation of prostaglandins E2 (PGE2) and tumor necrosis factor-α (TNF-α) in serum of formaldehyde-induced arthritic animals. The results elaborated significant reduction in albumin denaturation and remarkable progress on stabilization of red blood cells outer membrane at higher concentration during in vitro experiments. The ephedrine (40mg/kg) revealed noteworthy (p<0.001) inhibition in paw swelling in animals intoxicated with albumin as well as formaldehyde as compared to animals of control group by in vivo results. In this assay, ephedrine (20 & 40 mg/kg orally) significantly suppressed the level of these inflammatory markers (PGE2 & TNF-α). Ephedrine exhibited anti-arthritic effect by decreasing pro-inflammatory cytokines (PGE2 & TNF-α). This experimental work pharmacologically supports the use of ephedrine as anti-rheumatic drug but limited to evaluate in immunological arthritic model.


Asunto(s)
Artritis Reumatoide/tratamiento farmacológico , Efedrina/uso terapéutico , Albúminas/química , Albúminas/toxicidad , Animales , Artritis Reumatoide/inducido químicamente , Bovinos , Dinoprostona/sangre , Relación Dosis-Respuesta a Droga , Edema/inducido químicamente , Efedrina/administración & dosificación , Efedrina/química , Membrana Eritrocítica/efectos de los fármacos , Humanos , Inflamación/inducido químicamente , Inflamación/tratamiento farmacológico , Ratas , Factor de Necrosis Tumoral alfa/sangre
2.
Biomed Pharmacother ; 141: 111838, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34182414

RESUMEN

Obesity is known as metabolic syndrome and it affects many tissues including adipose tissue, liver, and central nervous system (CVS). Gambi-jung (GBJ) is a modified prescription of Taeumjowi-tang (TJT), which has been used to treat obesity in Korea. GBJ is composed of 90% Ephedra sinica Stapf (ES). Therefore, the present study was designed to assess the antiobesity effects of GBJ and to compare the effects of GBJ and ES on obesity. GBJ administration remarkably reduced the body weight, Body mass index (BMI), and body fat percentage compared to the ES administration in human subjects. GBJ-treated mice had lower white adipose tissue (WAT) amounts than ES-treated mice. GBJ and ES administration enhanced adenosine monophosphate-activated protein kinase (AMPK) expression in 3T3-L1 adipocytes, epididymal WAT and liver of HFD-induced obese mice. Moreover, GBJ and ES reduced food intake by suppressing the mRNA levels of orexigenic peptides, agouti-related protein (AgRP) and neuropeptide-Y (NPY), as well as AMPK in the brain of HFD-induced obese mice. Furthermore, GBJ-treated mice had dramatically lower expression of macrophage marker F4/80 in epididymal WAT than those of ES-treated mice. Based on these results, we suggest the use of GBJ as a natural drug to control weight gain.


Asunto(s)
Fármacos Antiobesidad/uso terapéutico , Obesidad/tratamiento farmacológico , Extractos Vegetales/uso terapéutico , Células 3T3-L1 , Tejido Adiposo Blanco/efectos de los fármacos , Adulto , Anciano , Animales , Depresores del Apetito/química , Depresores del Apetito/farmacología , Composición Corporal/efectos de los fármacos , Índice de Masa Corporal , Ingestión de Alimentos/efectos de los fármacos , Ephedra sinica/química , Efedrina/química , Efedrina/farmacología , Femenino , Humanos , Sistema de Señalización de MAP Quinasas , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Pérdida de Peso/efectos de los fármacos
3.
Artículo en Inglés | MEDLINE | ID: mdl-32866937

RESUMEN

A hybrid micelle based mobile phase was used to develop and validate a liquid chromatographic method for the separation and quantification of two local anesthetics namely; lidocaine hydrochloride (LID), and bupivacaine hydrochloride (BPV) in presence of the frequently co administered vasopressors phenyl ephrine (PHR) and ephedrine (EPH). Optimization of chromatographic separation conditions was performed applying experimental one factor at a time tool, and design of experiment, where the retention behavior of all analytes using both optimization protocols was in accordance. Chromatographic separation was carried on a C8 column operating at 40 °C at a flow rate of 1.5 mL/min. using a mobile phase consisting of 0.18 M sodium dodecyl sulphate, 10% acetonitrile, containing 0.3% triethyl amine and adjusted to pH 7 using 2 M ortho phosphoric acid, adopting UV detection at 230 nm. The proposed method was fully validated and applied to both in vitro and in vivo analysis of rat blood samples. The pharmacokinetics of both LID and BPV was followed when they were solitary injected or when co administered with either PHR or EPH. Moreover, the in vitro spiked experiment was also subjected to documented bio-analytical validation procedures.


Asunto(s)
Anestésicos Locales , Cromatografía Liquida/métodos , Monitoreo de Drogas/métodos , Vasoconstrictores , Anestésicos Locales/sangre , Anestésicos Locales/química , Anestésicos Locales/farmacocinética , Animales , Bupivacaína/sangre , Bupivacaína/química , Bupivacaína/farmacocinética , Interacciones Farmacológicas , Efedrina/sangre , Efedrina/química , Efedrina/farmacocinética , Lidocaína/sangre , Lidocaína/química , Lidocaína/farmacocinética , Micelas , Ratas , Vasoconstrictores/sangre , Vasoconstrictores/química , Vasoconstrictores/farmacocinética
4.
Chem Pharm Bull (Tokyo) ; 68(2): 140-149, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32009081

RESUMEN

Previously, we reported that the c-Met inhibitory effect of Ephedra Herb extract (EHE) is derived from ingredients besides ephedrine alkaloids. Moreover, analgesic and anti-influenza activities of EHE and ephedrine alkaloids-free Ephedra Herb extract (EFE) have been reported recently. In this study, we examined the fractions containing c-Met kinase inhibitory activity from EHE and the fractions with analgesic and anti-influenza activities from EFE, and elucidated the structural characteristics of the active fractions. Significant c-Met kinase activity was observed in 30, 40, and 50% methanol (MeOH) eluate fractions obtained from water extract of EHE using Diaion HP-20 column chromatography. Similarly, 20 and 40% MeOH, and MeOH eluate fractions obtained from water extract of EFE were found to display analgesic and anti-influenza activities. Reversed phase-HPLC analysis of the active fractions commonly showed broad peaks characteristic of high-molecular mass condensed tannin. The active fractions were analyzed using 13C-NMR and decomposition reactions; the deduced structures of active components were high-molecular mass condensed tannins, which were mainly procyanidin B-type and partly procyanidin A-type, including pyrogallol- and catechol-type flavan 3-ols as extension and terminal units. HPLC and gel permeation chromatography (GPC) analyses estimated that the ratio of pyrogallol- and catechol-type was approximately 9 : 2, and the weight-average molecular weight based on the polystyrene standard was >45000. Furthermore, GPC-based analysis was proposed as the quality evaluation method for high-molecular mass condensed tannin in EHE and EFE.


Asunto(s)
Ephedra/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Alcaloides/química , Alcaloides/farmacología , Analgésicos/química , Analgésicos/farmacología , Animales , Antivirales/química , Antivirales/farmacología , Biflavonoides/química , Biflavonoides/farmacología , Catequina/química , Catequina/farmacología , Línea Celular Tumoral , Perros , Efedrina/química , Efedrina/farmacología , Humanos , Células de Riñón Canino Madin Darby , Masculino , Ratones , Proantocianidinas/química , Proantocianidinas/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-met/antagonistas & inhibidores
5.
Biol Pharm Bull ; 41(2): 247-253, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29386484

RESUMEN

Ephedrine alkaloids-free Ephedra Herb extract (EFE) has been developed to eliminate the adverse effects caused by ephedrine alkaloid-induced sympathetic hyperactivation. Previously, we reported that EFE possesses analgesic, anti-influenza, and cancer metastatic inhibitory effects at comparable levels to that of Ephedra Herb extract (EHE). However, it has not yet been demonstrated that EFE is free from the known side effects of EHE, such as excitation, insomnia, and arrhythmias. In this study, the incidence of these adverse effects was compared between mice administered EHE and those administered EFE. Increased locomotor activity in an open-field test, reduced immobility times in a forced swim test, and reduced sleep times in a pentobarbital-induced sleep test were observed in EHE-treated mice, when compared to the corresponding values in vehicle-treated mice. In contrast, EFE had no obvious effects in these tests. In electrocardiograms, atrial fibrillation (i.e., irregular heart rhythm, absence of P waves, and appearance of f waves) was observed in the EHE-treated mice. It was suggested that this atrial fibrillation was induced by stimulation of adrenaline ß1 receptors, but not by hypokalemia. However, EFE did not affect cardiac electrophysiology. These results suggest that the abovementioned side effects are caused by ephedrine alkaloids in EHE, and that EFE is free from these adverse effects, such as excitation, insomnia, and arrhythmias. Thus, EFE is a promising new botanical drug with few adverse effects.


Asunto(s)
Ansiedad/prevención & control , Arritmias Cardíacas/prevención & control , Suplementos Dietéticos/efectos adversos , Ephedra/química , Efedrina/efectos adversos , Extractos Vegetales/efectos adversos , Trastornos del Inicio y del Mantenimiento del Sueño/prevención & control , Alcaloides/análisis , Alcaloides/toxicidad , Analgésicos no Narcóticos/administración & dosificación , Analgésicos no Narcóticos/efectos adversos , Analgésicos no Narcóticos/química , Animales , Animales no Consanguíneos , Ansiedad/sangre , Ansiedad/inducido químicamente , Ansiedad/etiología , Arritmias Cardíacas/sangre , Arritmias Cardíacas/inducido químicamente , Arritmias Cardíacas/etiología , Conducta Animal , Cafeína/envenenamiento , Estimulantes del Sistema Nervioso Central/envenenamiento , Suplementos Dietéticos/análisis , Efedrina/administración & dosificación , Efedrina/química , Contaminación de Alimentos , Hipnóticos y Sedantes/farmacología , Japón , Masculino , Ratones , Pentobarbital/farmacología , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Tallos de la Planta/química , Potasio/sangre , Trastornos del Inicio y del Mantenimiento del Sueño/sangre , Trastornos del Inicio y del Mantenimiento del Sueño/inducido químicamente , Trastornos del Inicio y del Mantenimiento del Sueño/etiología
6.
J Am Chem Soc ; 139(12): 4294-4297, 2017 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-28274119

RESUMEN

We report the use of a chiral Cu(II) 3D metal-organic framework (MOF) based on the tripeptide Gly-l-His-Gly (GHG) for the enantioselective separation of metamphetamine and ephedrine. Monte Carlo simulations suggest that chiral recognition is linked to preferential binding of one of the enantiomers as a result of either stronger or additional H-bonds with the framework that lead to energetically more stable diastereomeric adducts. Solid-phase extraction of a racemic mixture by using Cu(GHG) as the extractive phase permits isolating >50% of the (+)-ephedrine enantiomer as target compound in only 4 min. To our knowledge, this represents the first example of a MOF capable of separating chiral polar drugs.


Asunto(s)
Cobre/química , Efedrina/aislamiento & purificación , Estructuras Metalorgánicas/química , Metanfetamina/aislamiento & purificación , Péptidos/química , Efedrina/química , Metanfetamina/química , Simulación de Dinámica Molecular , Estructura Molecular , Método de Montecarlo , Estereoisomerismo
7.
J Nat Med ; 70(3): 571-83, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26943796

RESUMEN

It is generally accepted that the primary pharmacological activities and adverse effects of Ephedra Herb are caused by ephedrine alkaloids. Interestingly, our research shows that Ephedra Herb also has ephedrine alkaloid-independent pharmacological actions, such as c-MET inhibitory activity. This study describes the preparation of an ephedrine alkaloids-free Ephedra Herb extract (EFE) by ion-exchange column chromatography, as well as in vitro and in vivo evaluation of its pharmacological actions and toxicity. We confirmed that EFE suppressed hepatocyte growth factor (HGF)-induced cancer cell motility by preventing both HGF-induced phosphorylation of c-Met and its tyrosine kinase activity. We also investigated the analgesic effect of EFE. Although the analgesic effect of Ephedra Herb has traditionally been attributed to pseudoephedrine, oral administration of EFE reduced formalin-induced pain in a dose-dependent manner in mice. Furthermore, we confirmed the anti-influenza virus activity of EFE by showing inhibition of MDCK cell infection in a concentration-dependent manner. All assessments of toxicity, even after repeated oral administration, suggest that EFE would be a safer alternative to Ephedra Herb. The findings described here suggest that EFE has c-Met inhibitory action, analgesic effect, and anti-influenza activity, and that it is safer than Ephedra Herb extract itself. Therefore, EFE could be a useful pharmacological agent.


Asunto(s)
Analgésicos/uso terapéutico , Antineoplásicos/uso terapéutico , Ephedra/química , Efedrina/química , Gripe Humana/tratamiento farmacológico , Alcaloides/química , Efedrina/análisis , Humanos
8.
J Nat Med ; 70(3): 554-62, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26976141

RESUMEN

Ephedrine alkaloids (EAs) have been considered the main pharmacologically active substances in Ephedra Herb (, Mao; EH) since they were first identified by Prof. N. Nagai, and are known to induce palpitation, hypertension, insomnia, and dysuria as side effects. Therefore, the administration of drugs containing EH to patients with cardiovascular-related diseases is severely contraindicated. While our previous studies suggest that some of the effects of EH may not be due to EAs, considering their side effects would be expedient to develop a new EAs-free EH extract (EFE). Here, we established a preparation method for EFE and revealed its chemical composition, including the content of herbacetin, a flavonoid aglycon present in EH and a potential putative marker for EFE quality control. In addition, we showed the antiproliferative effects of EFE against the H1975 non-small cell lung cancer (NSCLC) cell line. EFE was prepared from EH extract using the ion exchange resin SK-1B. LC/Orbitrap MS analysis revealed the removal of EAs, 6-methoxykynurenic acid, and 6-hydroxykynurenic acid from the original extract. Quantitative analysis of herbacetin using LC/MS in acid-hydrolyzed EFE showed that its content was 0.104 %. Although several alkaloidal constituents were removed from EH extract, the antiproliferative effect of EFE against H1975 cells was comparable to that of EH extract. These results indicate that EFE retained the anticancer effect of EH and demonstrated its potential for future development as a new herbal medicine with reduced side effects.


Asunto(s)
Alcaloides/química , Medicamentos Herbarios Chinos/química , Ephedra/química , Efedrina/química , Extractos Vegetales/química , Efedrina/análisis , Humanos
9.
Nucl Med Biol ; 40(3): 331-7, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23306137

RESUMEN

INTRODUCTION: Most radiotracers for imaging of cardiac sympathetic innervation are substrates of the norepinephrine transporter (NET). The goal of this study was to characterize the NET transport kinetics and binding affinities of several sympathetic nerve radiotracers, including [(11)C]-(-)-meta-hydroxyephedrine, [(11)C]-(-)-epinephrine, and a series of [(11)C]-labeled phenethylguanidines under development in our laboratory. For comparison, the NET transport kinetics and binding affinities of some [(3)H]-labeled biogenic amines were also determined. METHODS: Transport kinetics studies were performed using rat C6 glioma cells stably transfected with the human norepinephrine transporter (C6-hNET cells). For each radiolabeled NET substrate, saturation transport assays with C6-hNET cells measured the Michaelis-Menten transport constants Km and Vmax for NET transport. Competitive inhibition binding assays with homogenized C6-hNET cells and [(3)H]mazindol provided estimates of binding affinities (KI) for NET. RESULTS: Km, Vmax and KI values were determined for each NET substrate with a high degree of reproducibility. Interestingly, C6-hNET transport rates for 'tracer concentrations' of substrate, given by the ratio Vmax/Km, were found to be highly correlated with neuronal transport rates measured previously in isolated rat hearts (r(2)=0.96). This suggests that the transport constants Km and Vmax measured using the C6-hNET cells accurately reflect in vivo transport kinetics. CONCLUSION: The results of these studies show how structural changes in NET substrates influence NET binding and transport constants, providing valuable insights that can be used in the design of new tracers with more optimal kinetics for quantifying regional sympathetic nerve density.


Asunto(s)
Efedrina/análogos & derivados , Epinefrina/metabolismo , Corazón/inervación , Proteínas de Transporte de Noradrenalina a través de la Membrana Plasmática/metabolismo , Sistema Nervioso Simpático/diagnóstico por imagen , Animales , Transporte Biológico , Línea Celular Tumoral , Efedrina/química , Efedrina/metabolismo , Epinefrina/química , Humanos , Cinética , Tomografía de Emisión de Positrones , Unión Proteica , Trazadores Radiactivos , Ratas , Relación Estructura-Actividad
10.
Anal Bioanal Chem ; 404(8): 2407-16, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22945558

RESUMEN

A new mechanism is proposed that describes the gas-phase separation of chiral molecules found in amphetamine-type substances (ATS) by the use of high-resolution ion mobility spectrometry (IMS). Straight-chain achiral alcohols of increasing carbon chain length, from methanol to n-octanol, are used as drift gas modifiers in IMS to highlight the mechanism proposed for gas-phase separations of these chiral molecules. The results suggest the possibility of using these achiral modifiers to separate the chiral molecules (R,S) and (S,R)-ephedrine and (S,S) and (R,R)-pseudoephedrine which contain an internal hydroxyl group at the first chiral center and an amino group at the other chiral center. Ionization was achieved with an electrospray source, the ions were introduced into an IMS with a resolving power of 80, and the resulting ion clusters were characterized with a coupled quadrupole mass spectrometer detector. A complementary computational study conducted at the density functional B3LYP/6-31g level of theory for the electronic structure of the analyte-modifier clusters was also performed, and showed either "bridged" or "independent" binding. The combined experimental and simulation data support the proposed mechanism for gas-phase chiral separations using achiral modifiers in the gas phase, thus enhancing the potential to conduct fast chiral separations with relative ease and efficiency.


Asunto(s)
Química Farmacéutica/métodos , Efedrina/análisis , Seudoefedrina/análisis , 1-Octanol/química , Técnicas de Química Analítica , Química Farmacéutica/normas , Efedrina/química , Gases/química , Espectrometría de Masas , Seudoefedrina/química , Estereoisomerismo
11.
J Chromatogr A ; 1257: 158-70, 2012 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-22907044

RESUMEN

The partial conversion of methanol (MeOH) to formaldehyde (HCHO) in the gas chromatograph (GC) injection port was studied. The presence of formaldehyde in the injection port can result in reaction with injected analytes, especially primary and secondary amines. A systematic study of this problem was undertaken using norephedrine and ephedrine as probe analytes, and experiments involving varying inlet temperature, comparisons among solvents and solvent mixtures, isotopic labeling, and formaldehyde spiking. These experiments showed a direct correlation between inlet temperature and formation of the amine-formaldehyde condensation products. The mass spectra of the norephedrine and ephedrine condensation products were consistent with addition of the methylene group derived from formaldehyde across the amine and alcohol moieties to form the corresponding oxazolidine-ring compounds. Results for the imine condensation product of didesmethylsibutramine formed in the injection port are also presented.


Asunto(s)
Aminas/química , Formaldehído/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Metanol/química , Ciclobutanos/química , Efedrina/química , Formaldehído/análisis , Cromatografía de Gases y Espectrometría de Masas/instrumentación , Iminas/química , Metanol/análisis , Oxazoles/química , Fenilpropanolamina/química , Solventes/análisis , Solventes/química , Temperatura
12.
J Anal Toxicol ; 36(6): 381-9, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22593565

RESUMEN

In recent years, derivatives of cathinone, a naturally occurring beta-keto phenylethylamine, have entered the illicit drug market. These compounds have been marketed over the internet or in so-called head shops as "legal highs" and have gained popularity among drug users. Numerous fatalities due to the abuse of these drugs in recent years have increased the need for their detection in human blood samples. For detection and determination of 25 designer cathinones and their related ephedrines in blood samples, a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed using only 100 µL of blood. The blood was extracted using liquid-liquid extraction with 1 mL of 1-chlorobutane containing 10% of isopropanol. The final extract was analyzed using a Shimadzu 8030 LC-MS-MS system operated in electrospray positive ionization multiple reaction monitoring mode. The method has been validated according to international guidelines and was found to be selective for all tested compounds. Calibration for all 25 studied analytes was satisfactory from 10-1,000 ng/mL. Accuracy data were within the acceptance interval of ±15% [±20% at the lower limit of quantification (LLOQ)] of the nominal values for all drugs. Within-day (repeatability) and intermediate precision data were within the required limits of 15% relative standard deviation (RSD) (20% RSD at LLOQ).


Asunto(s)
Alcaloides/química , Drogas de Diseño/análisis , Drogas Ilícitas/sangre , Psicotrópicos/sangre , Detección de Abuso de Sustancias , Alcaloides/sangre , Calibración , Estimulantes del Sistema Nervioso Central/sangre , Estimulantes del Sistema Nervioso Central/química , Cromatografía Líquida de Alta Presión , Drogas de Diseño/química , Efedrina/sangre , Efedrina/química , Toxicología Forense/métodos , Guías como Asunto , Humanos , Drogas Ilícitas/química , Agencias Internacionales , Límite de Detección , Microquímica/métodos , Psicotrópicos/química , Reproducibilidad de los Resultados , Espectrometría de Masa por Ionización de Electrospray , Detección de Abuso de Sustancias/normas , Espectrometría de Masas en Tándem
13.
Chirality ; 23(8): 593-601, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21780193

RESUMEN

Methylamphetamine, ephedrine, and pseudoephedrine were derivatized using trifluoroacetic anhydride and enantiomers of each were analyzed using gas chromatography coupled to mass spectrometry (GC/MS) fitted with a γ-cyclodextrin (Chiraldex™ G-PN) chiral column. A temperature-programmed method was developed and optimized and the results compared with those obtained using a previously published isothermal GC method applied to GC/MS analysis. Trifluoroacetylated 3-(trifluoromethyl)phenethylamine hydrochloride was used as an internal standard, and mass fragmentation patterns are proposed for all derivatives analyzed. Qualitative validation of the optimized chromatographic conditions was completed in accordance with the guidelines published by the United Nations Office on Drugs and Crime (UNODC). Under conditions of repeatability and reproducibility, the method gave relative retention times with a relative standard deviation of less than 0.02% for all six analytes of interest. This surpasses the UNODC's acceptance criteria of 2% for validation of qualitative precision. Ephedrine and pseudoephedrine are common precursors in the clandestine manufacture of methylamphetamine. Seizures of illicit methylamphetamine therefore often contain mixtures of these optically active compounds. The simultaneous enantioseparation of these compounds to produce a profile would provide valuable information to law enforcement agencies regarding the provenance of a methylamphetamine seizure.


Asunto(s)
Efedrina/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Metanfetamina/análisis , Seudoefedrina/análisis , Estudios de Validación como Asunto , Ciclodextrinas/química , Efedrina/química , Límite de Detección , Metanfetamina/química , Seudoefedrina/química , Estándares de Referencia , Reproducibilidad de los Resultados , Estereoisomerismo
14.
J Chromatogr A ; 1218(9): 1266-72, 2011 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-21256502

RESUMEN

The compound 3,4-dimethyl-5-phenyl-1,3-oxazolidine can appear as an artifact during the gas chromatographic analysis of ephedrines. Its presence is a risk for doping control and forensic analyses. An evaluation about the consequences of its formation showed the possibility of a false positive for ephedrine, a false negative for pseudophedrine and increased uncertainty in the quantitative approach. Misinterpretations can be avoided with the observation of fragments m/z 56 and 71 in the ephedrine mass spectrum during GC-MS analysis and also by the formation of N-TFA-O-TBDMS derivatives prior to GC analysis. These N-TFA-O-TBDMS derivatives lead to an increase in the number and mass of diagnostic ions, meet the identification criteria, and provide an improvement in chromatographic resolution, allowing the separation of the ephedrines.


Asunto(s)
Cromatografía de Gases/métodos , Efedrina/orina , Éteres/química , Fluoroacetatos , Oxazoles/química , Silanos/química , Artefactos , Efedrina/análogos & derivados , Efedrina/química , Modelos Lineales , Ácido Trifluoroacético/química
15.
Phytochemistry ; 71(8-9): 895-903, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20417943

RESUMEN

Ephedra sinica Stapf (Ephedraceae) is a widely used Chinese medicinal plant (Chinese name: Ma Huang). The main active constituents of E. sinica are the unique and taxonomically restricted adrenergic agonists phenylpropylamino alkaloids, also known as ephedrine alkaloids: (1R,2S)-norephedrine (1S,2S)-norpseudoephedrine, (1R,2S)-ephedrine, (1S,2S)-pseudoephedrine, (1R,2S)-N-methylephedrine and (1S,2S)-N-methylpseudoephedrine. GC-MS analysis of freshly picked young E. sinica stems enabled the detection of 1-phenylpropane-1,2-dione and (S)-cathinone, the first two putative committed biosynthetic precursors to the ephedrine alkaloids. These metabolites are only present in young E. sinica stems and not in mature stems or roots. The related Ephedra foemina and Ephedra foliata also lack ephedrine alkaloids and their metabolic precursors in their aerial parts. A marked diversity in the ephedrine alkaloids content and stereochemical composition in 16 different E. sinica accessions growing under the same environmental conditions was revealed, indicating genetic control of these traits. The accessions can be classified into two groups according to the stereochemistry of the products accumulated: a group that displayed only 1R stereoisomers, and a group that displayed both 1S and 1R stereoisomers. (S)-cathinone reductase activities were detected in E. sinica stems capable of reducing (S)-cathinone to (1R,2S)-norephedrine and (1S,2S)-norpseudoephedrine in the presence of NADH. The proportion of the diastereoisomers formed varied according to the accession tested. A (1R,2S)-norephedrine N-methyltransferase capable of converting (1R,2S)-norephedrine to (1R,2S)-ephedrine in the presence of S-adenosylmethionine (SAM) was also detected in E. sinica stems. Our studies further support the notion that 1-phenylpropane-1,2-dione and (S)-cathinone are biosynthetic precursors of the ephedrine alkaloids in E. sinica stems and that the activity of (S)-cathinone reductases directs and determines the stereochemical branching of the pathway. Further methylations are likely due to N-methyltransferase activities.


Asunto(s)
Alcaloides , Medicamentos Herbarios Chinos/química , Ephedra sinica/química , Efedrina , Metiltransferasas/metabolismo , Oxidorreductasas/metabolismo , Alcaloides/análisis , Alcaloides/química , Alcaloides/aislamiento & purificación , Alcaloides/metabolismo , Disacáridos , Medicamentos Herbarios Chinos/análisis , Medicamentos Herbarios Chinos/aislamiento & purificación , Ephedra sinica/enzimología , Efedrina/análogos & derivados , Efedrina/análisis , Efedrina/química , Efedrina/aislamiento & purificación , Glucuronatos , Estructura Molecular , Estereoisomerismo
16.
Anal Chem ; 80(14): 5334-41, 2008 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-18558771

RESUMEN

Numerous gas-sensing devices are based on infrared laser spectroscopy. In this paper, the technique is further developed and, for the first time, applied to forensic urinalysis. For this purpose, a difference frequency generation laser was coupled to an in-house-built, high-temperature multipass cell (HTMC). The continuous tuning range of the laser was extended to 329 cm(-1) in the fingerprint C-H stretching region between 3 and 4 microm. The HTMC is a long-path absorption cell designed to withstand organic samples in the vapor phase (Bartlome, R.; Baer, M.; Sigrist, M. W. Rev. Sci. Instrum. 2007, 78, 013110). Quantitative measurements were taken on pure ephedrine and pseudoephedrine vapors. Despite featuring similarities, the vapor-phase infrared spectra of these diastereoisomers are clearly distinguishable with respect to a vibrational band centered at 2970.5 and 2980.1 cm(-1), respectively. Ephedrine-positive and pseudoephedrine-positive urine samples were prepared by means of liquid-liquid extraction and directly evaporated in the HTMC without any preliminary chromatographic separation. When 10 or 20 mL of ephedrine-positive human urine is prepared, the detection limit of ephedrine, prohibited in sports as of 10 microg/mL, is 50 or 25 microg/mL, respectively. The laser spectrometer has room for much improvement; its potential is discussed with respect to doping agents detection.


Asunto(s)
Gases/química , Gases/orina , Rayos Láser , Espectrofotometría Infrarroja/instrumentación , Espectrofotometría Infrarroja/métodos , Orina/química , Efedrina/análogos & derivados , Efedrina/química , Efedrina/orina , Salud , Humanos , Estructura Molecular , Probabilidad , Sensibilidad y Especificidad , Estereoisomerismo , Temperatura , Urinálisis , Vibración
18.
Drug Dev Ind Pharm ; 32(3): 367-76, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16556541

RESUMEN

Three near zero-order controlled-release pseudoephedrine hydrochloride (PEH) formulations demonstrating proportional release rates were developed using 3-Dimensional Printing (3-DP) technology. Mixtures of Kollidon SR and hydroxypropylmethyl cellulose (HPMC) were used as drug carriers. The release rates were adjusted by varying the Kollidon SR-HPMC ratio while keeping fabrication parameters constant. The dosage forms were composed of an immediate release core and a release rate regulating shell, fabricated with an aqueous PEH and an ethanolic triethyl citrate (TEC) binder, respectively. The dosage form design called for the drug to be released via diffusional pathways formed by HPMC in the shell matrix. The release rate was shown to increase correspondingly with the fraction of HPMC contained in the polymer blend. The designed formulations resulted in dosage forms that were insensitive to changes in pH of the dissolution medium, paddle stirring rate, and the presence/absence of a sinker. The near zero-order release properties were unchanged regardless of the dissolution test being performed on either single cubes or on a group of eight cubes encased within a gelatin capsule shell. The chemical and dissolution properties of the three formulations remained unchanged following 1 month's exposure to 25 degrees C/60% RH or 40 degrees C/75% RH environment under open container condition. The in vivo performance of the three formulations was evaluated using a single-dose, randomized, open-label, four-way crossover clinical study composed of 10 fasted healthy volunteers. The pharmacokinetic parameters were analyzed using a noncompartmental model. Qualitative rank order linear correlations between in vivo absorption profiles and in vitro dissolution parameters (with slope and intercept close to unity and origin, respectively) were obtained for all three formulations, indicating good support for a Level A in vivo/in vitro correlation.


Asunto(s)
Efedrina/química , Efedrina/farmacocinética , Metilcelulosa/análogos & derivados , Povidona/química , Tecnología Farmacéutica/instrumentación , Adulto , Área Bajo la Curva , Estudios Cruzados , Preparaciones de Acción Retardada , Relación Dosis-Respuesta a Droga , Estabilidad de Medicamentos , Efedrina/administración & dosificación , Calor , Humanos , Concentración de Iones de Hidrógeno , Derivados de la Hipromelosa , Masculino , Metilcelulosa/química , Solubilidad , Agua/química
19.
Int J Pharm ; 272(1-2): 19-27, 2004 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-15019065

RESUMEN

This study examined the release of acetaminophen (APAP) from hydroxypropyl methylcellulose (HPMC) and hydroxypropyl cellulose (HPC) matrices. The effect of pseudoephedrine (PE) as a co-active, HPMC:HPC ratio, polymer loading, pH of the dissolution media, and compression force on APAP release were studied. Granules formulated with APAP or both APAP and PE, and various blends of HPMC and HPC were compressed into tablets at different compression forces. APAP release from the matrix tablets was not considerably influenced by changes in HPMC:HPC ratio or compression force. The rate of drug release was significantly affected by pH of the dissolution media, total polymer loading, and the presence of PE. Drug release from the formulations containing both APAP and PE was slower than those containing only APAP. Drug release from tablets formulated with APAP only showed an initial burst at pH 1.16 or 7.45. Formulations containing both APAP and PE showed slower drug release at pH 1.16 than at pH 7.4. The drug release data showed a good fit to the Power Law Model. The mechanism of drug release is consistent with a complex behavior. The results of the tablet erosion studies indicated that the amount of APAP released was linearly related to the percentage of tablet weight loss. The kinetics of tablet water uptake was consistent with a diffusion and stress relaxation mechanism.


Asunto(s)
Acetaminofén/química , Celulosa/análogos & derivados , Celulosa/química , Portadores de Fármacos/química , Metilcelulosa/química , Acetaminofén/administración & dosificación , Química Farmacéutica , Preparaciones de Acción Retardada , Efedrina/química , Concentración de Iones de Hidrógeno , Derivados de la Hipromelosa , Cinética , Metilcelulosa/análogos & derivados , Solubilidad , Comprimidos , Factores de Tiempo , Agua/química
20.
Org Lett ; 4(17): 2841-4, 2002 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-12182569

RESUMEN

[structure: see text] A highly convergent synthesis of the proposed structure of amphidinolide A is reported. Instructive applications of several organometallic processes are illustrated, including a highly selective ring-closing metathesis reaction.


Asunto(s)
Lactonas/síntesis química , Macrólidos/síntesis química , Toxinas Marinas/síntesis química , Antineoplásicos/síntesis química , Ciclización , Efedrina/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA