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1.
Int J Pharm ; 416(1): 384-93, 2011 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-21745558

RESUMEN

To improve visualization of nanoparticles within the cells' compartments, we synthesized a coumarin based fluorescent derivative, tetradecyl diethylamino coumarin amid, 14-DACA. In this compound the coumarin chromophore is linked with a tetradecyl alkyl chain that contributes to lipophilicity and slightly amphiphilic character of this probe. 14-DACA exhibits good biocompatibility, its solubility and emission spectrum are not sensitive to changes in pH value. Solid lipid nanoparticles (SLN) labeled with 14-DACA (SLN-D) and frequently used 6-coumarin (SLN-C) were utilized to evaluate probes' properties in the trafficking and intracellular localization of nanoparticles. SLN-D were seen as distinct blue dots in the cellular environment in contrast to SLN-C which were hardly to recognize due to the self-quenching of 6-coumarin, its leakage and distribution in intracellular compartments. Spectra of 14-DACA indicated the possibility of spectral resolution from both green and red fluorophores allowing clear multicolor imaging of organelles in both fixed and living cells. The results showed valuableness of new probe for trafficking of the drug nanocarriers intracellularly in a kinetic and sensitive manner. Such studies are of great importance in investigations aimed to clarify subcellular targeted drug delivery, controlled release and even to identify toxicological changes.


Asunto(s)
Cumarinas/farmacocinética , Composición de Medicamentos/métodos , Colorantes Fluorescentes/síntesis química , Colorantes Fluorescentes/farmacocinética , Microscopía Fluorescente/métodos , Nanopartículas/química , Ciclo Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cumarinas/efectos adversos , Cumarinas/síntesis química , Cumarinas/química , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Colorantes Fluorescentes/química , Humanos , Nanopartículas/ultraestructura , Tamaño de la Partícula , Propiedades de Superficie , Tiazoles/química , Tiazoles/farmacocinética
2.
Org Biomol Chem ; 9(11): 4150-9, 2011 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-21505664

RESUMEN

A serious drawback of ESR, particularly in its application to cells, is the lack of information on the location of spin probes in the system. In order to realize real time tracking, a spin probe was combined with a fluorophore in a new kind of nitroxide-fluorophore double probe which, in addition to information about lipid dynamics, enables visualization by fluorescence microscopy. The two sets of probes synthesized are based on an amino-alkyne-functionalized sugar that serves as a central polar group and as a linker between the 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) fluorophore and the derivative of the spin labelled fatty acid. In this setting, the location of the fluorophore is restricted to the water-lipid interface, while the nitroxide is located deep in the lipid bilayer. Preliminary tests on cells show preferential localization of both probes in the plasma membrane, with a relatively slow redistribution to other membranes of the cell. We believe that such double probes would be particularly useful for studies of plasma membrane heterogeneity and associated cellular processes.


Asunto(s)
Fluorescencia , Colorantes Fluorescentes/química , Óxidos de Nitrógeno/química , Línea Celular Tumoral , Espectroscopía de Resonancia por Spin del Electrón , Colorantes Fluorescentes/síntesis química , Humanos , Procesamiento de Imagen Asistido por Computador , Microscopía Confocal , Microscopía Fluorescente , Estructura Molecular , Óxidos de Nitrógeno/síntesis química , Estereoisomerismo
3.
Acta Chim Slov ; 58(2): 295-310, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24062040

RESUMEN

Mur ligases are essential enzymes involved in the cytoplasmic steps of peptidoglycan synthesis which remain attractive, yet unexploited targets. In order to develop new antibacterial agents, we have designed a series of new MurC and MurD inhibitors bearing amino acid sulfonohydrazide moiety. The L-Leu series of this class displayed the highest enzyme inhibition with IC50 in the concentration range between 100 and 500 µM, with L-Thr, L-Pro and L-Ala derivatives being inactive. The most promising compound of the series also expressed weak antibacterial activity against S. aureus with MIC = 128 µg/mL.

4.
Gen Physiol Biophys ; 29(4): 373-80, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21157000

RESUMEN

Sodium nitroprusside (SNP) is a nitric oxide (•NO) donor in vitro and in vivo. In this paper the time variation of the intracellular water proton nuclear magnetic resonance (NMR) effective relaxation time T'(2a) in SNP-treated human erythrocyte suspensions, containing 10 mM membrane impermeable paramagnetic MnCl2, has been measured. The observed T'(2a) time-course was analyzed in terms of the two mechanisms by which released •NO affects T'(2a). These are, respectively, enhancement of the intracellular water proton intrinsic NMR relaxation rate 1/T(2a) by paramagnetism of •NO subsequently bonded to iron atoms of intracellular deoxyhemoglobin, and suppression of diffusional water permeability P(d) as a consequence of nitrosylation of aquaporin-1 (AQP1) channel Cys189, either by direct reaction with •NO or with one of the •NO oxidation products, such as N2O3. The bound •NO on the Cys189 thiol residue appears to impose a less efficient barrier to water permeation through AQP1 than the larger carboxyphenylmercuryl residue from p-chloromercuribenzoate. The effect of •NO on P(d) is discussed in terms of NO-induced vasodilation.


Asunto(s)
Permeabilidad de la Membrana Celular/efectos de los fármacos , Membrana Eritrocítica/efectos de los fármacos , Membrana Eritrocítica/metabolismo , Espectroscopía de Resonancia Magnética/métodos , Donantes de Óxido Nítrico/farmacología , Nitroprusiato/farmacología , Agua/metabolismo , Difusión , Humanos , Espacio Intracelular/efectos de los fármacos , Espacio Intracelular/metabolismo , Cinética , Masculino
5.
Curr Med Chem ; 17(34): 4231-55, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20939815

RESUMEN

High-throughput screening (HTS) is one of the most powerful approaches available for identifying new lead compounds for the growing catalogue of validated drug targets. However, just as virtual and experimental HTS have accelerated lead identification and changed drug discovery, they have also introduced a large number of peculiar molecules. Some of these have turned out to be interesting for further optimization, others to be dead ends when attempts are made to optimize their activity, typically after a great deal of time and resources have been devoted. Such false positive hits are still one of the key problems in the field of HTS and in the early stages of drug discovery in general. Many studies have been devoted to understanding the origins of false-positives, and the findings have been incorporated in filters and methods that can predict and eliminate problematic molecules from further consideration. This paper will focus on the structural classes and known mechanisms of nonleadlike false positives, together with experimental and computational methods for identifying such compounds.


Asunto(s)
Descubrimiento de Drogas , Ensayos Analíticos de Alto Rendimiento , Preparaciones Farmacéuticas/química , Bioensayo , Simulación por Computador , Descubrimiento de Drogas/métodos , Reacciones Falso Positivas , Humanos , Modelos Químicos , Proyectos de Investigación , Estadística como Asunto
6.
AAPS PharmSciTech ; 11(3): 1485-92, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20845090

RESUMEN

The aim of this work was to test innovative approach for enhancing ascorbyl palmitate stability in microemulsions for topical application by addition of newly synthesized co-antioxidant 4-(tridecyloxy)benzaldehyde oxime (TDBO) and to investigate its antioxidant activity and finally to evaluate cytotoxicity of TDBO-loaded microemulsions on keratinocyte cells. TDBO significantly increased ascorbyl palmitate stability in oil-dispersed-in-water (o/w) microemulsions, most presumably due to reduction of ascorbyl palmitate radical back to ascorbyl palmitate, since TDBO free-radical scavenging activity was confirmed. Cytotoxicity experiments demonstrated no significant change in cell viability or morphology in the presence of TDBO-loaded microemulsions regarding unloaded microemulsions, although greater cytotoxicity was observed with increased microemulsion concentrations. Therefore, the incorporation of TDBO as non-cytotoxic co-antioxidant in o/w microemulsions is a promising new strategy for enhancing ascorbyl palmitate stability that could be used to support antioxidant network in the skin.


Asunto(s)
Antioxidantes/química , Antioxidantes/farmacología , Ácido Ascórbico/análogos & derivados , Emulsiones/síntesis química , Emulsiones/farmacología , Queratinocitos/efectos de los fármacos , Ácido Ascórbico/química , Ácido Ascórbico/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Composición de Medicamentos/métodos , Estabilidad de Medicamentos , Humanos , Irritantes , Queratinocitos/citología
7.
Nucl Med Commun ; 30(10): 807-14, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19623093

RESUMEN

OBJECTIVE: Yttrium-90 (Y)-labelled peptides such as DOTATOC and antibodies such as Zevalin are widely used in radionuclide therapy. Indium-111 (In) is used as a Y surrogate for imaging and dosimetry purposes. We aimed to investigate accuracy, geometry (vials and syringes) and volume dependencies for both radionuclides in several different radionuclide calibrators. METHODS: YCl3 and InCl3 solutions were gravimetrically dispensed into the most frequently used containers. In each container several dilutions of the parent solutions were performed. Mass, activity and time were recorded for each calibrator and measurement. Aliquots of both parent solutions were calibrated at the National Metrology Laboratory, Vienna, Austria (BEV). From our measurements and results from BEV, correction factors were determined and further partitioned into calibration, geometry and volume correction factors. RESULTS: Using the nominal calibration factors provided by the manufacturer, measured activity in P6 vials was overestimated by up to 25% for In, depending on the calibrator. Y activity was either underestimated (by up to 20%) or overestimated (by up to 25%) using different radionuclide calibrators. This is the result of the difference in containers used to set the manufacturer's calibration factor values and the containers used in nuclear medicine departments and in this study. There was little geometry dependence for glass vials but strong geometry dependence for syringes for both radionuclides in all calibrators. CONCLUSION: The results should constitute a warning for all personnel responsible for preparation of radiopharmaceuticals. Every nuclear medicine department should incorporate a proper quality-control regimen for radionuclide calibrators and a quality-assurance system.


Asunto(s)
Radioisótopos de Indio/análisis , Radiometría/métodos , Radiometría/normas , Manejo de Especímenes/métodos , Manejo de Especímenes/normas , Radioisótopos de Itrio/análisis , Dosis de Radiación , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Eslovenia
8.
Chem Phys Lipids ; 156(1-2): 17-25, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18835261

RESUMEN

Aqueous decanoic acid/sodium decanaote systems were studied as a function of pH and concentration, up to 0.3 M decanoic acid/sodium decanoate, by electron spin resonance (ESR) spectroscopy using three different amphiphilic spin labels. The distribution of the spin labels between vesicles and micelles as well as their dynamic properties were determined by quantitative analysis of the ESR spectra using two novel simulation software packages. Rotational correlation time of the labels in micelles was found to increase with decreasing pH, with substantial increase in the region where vesicles were formed (7.8

Asunto(s)
Ácidos Decanoicos/química , Espectroscopía de Resonancia por Spin del Electrón/métodos , Micelas , Marcadores de Spin , Concentración de Iones de Hidrógeno , Temperatura , Agua/química
9.
Molecules ; 13(1): 11-30, 2008 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-18259126

RESUMEN

A series of novel N-benzylidenesulfonohydrazide compounds were designed and synthesized as inhibitors of UDP-N-acetylmuramic acid: L-alanine ligase (MurC) and UDP-N-acetylmuramoyl-L-alanine: D-glutamate ligase (MurD) from E. coli, involved in the biosynthesis of bacterial cell-walls. Some compounds possessed inhibitory activity against both enzymes with IC(50) values as low as 30 microM. In addition, a new, one-pot synthesis of amidobenzaldehydes is reported.


Asunto(s)
Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Proteínas de Escherichia coli/antagonistas & inhibidores , Escherichia coli/enzimología , Péptido Sintasas/antagonistas & inhibidores , Piridazinas/síntesis química , Piridazinas/farmacología , Catálisis/efectos de los fármacos , Inhibidores Enzimáticos/química , Escherichia coli/efectos de los fármacos , Oxidación-Reducción/efectos de los fármacos , Polímeros , Piridazinas/química , Rodanina/química
10.
Bioelectrochemistry ; 70(2): 462-8, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-16935571

RESUMEN

The passage of water through the aquaporin-1 (AQP1) transmembrane channel protein of the human erythrocyte is known to be inhibited by organic mercurials such as p-chloromercuribenzoate (pCMB), which react with the free SH-group of the critical cysteine (Cys189) located near the constriction of the AQP1 water-specific channel. Sodium nitroprusside (SNP), which is known as a nitric oxide (NO) donor in interactions with SH-containing molecules, is shown here to suppress the diffusional water permeability (P(d)) of the erythrocyte membrane, presumably as a result of reaction with the Cys189 of the human erythrocyte AQP1 water channels. Further, treatment of erythrocytes with HgCl(2) is found to result in a cell volume decrease that can be related to activation of membrane K(+)-selective Gárdos channels and subsequent loss of intracellular K(+) and cell shrinkage. The variations in P(d) and volume of the erythrocyte were deduced from induced variations in the measured proton ((1)H) nuclear magnetic resonance (NMR) transverse (T(2)) relaxation functions of water exchanging between diamagnetic intracellular and paramagnetic extracellular compartments of the 20-25% hematocrit samples. The extracellular solvent contained 10 mM membrane-impermeable paramagnetic Mn(2+) ions. The (1)H-T(2) NMR technique allows determination of the time constant tau(exch) (for exchange of the erythrocyte intracellular water) that is inversely proportional to the permeability coefficient P(d) when the intracellular water volume is left unmodified, as in the case of SNP-treated erythrocytes. However, for HgCl(2)-treated erythrocytes, this technique showed simultaneous variation of both tau(exch) and the volume ratio V(in)/V(out) of intracellular and extracellular water in proportions suggesting that P(d) was left unmodified. The HgCl(2) effect has been found to be partly reversible by the reducing activity of added mercaptoethanol.


Asunto(s)
Permeabilidad de la Membrana Celular/fisiología , Membrana Eritrocítica/fisiología , Cloruro de Mercurio/administración & dosificación , Nitroprusiato/administración & dosificación , Agua/metabolismo , Permeabilidad de la Membrana Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Membrana Eritrocítica/efectos de los fármacos , Eritrocitos/efectos de los fármacos , Eritrocitos/fisiología
11.
J Phys Chem B ; 110(51): 25559-61, 2006 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-17181183

RESUMEN

Molecular dynamics simulation has been performed to investigate the structural properties of perifosine and its synthetic spin-labeled alkylphospholipid analogues. The conformations adopted by these compounds in water and in a dipalmitoylphosphatidylcholine bilayer as a function of the presence and position of the N-oxyl-4',4'-dimethyloxazolidine ring (doxyl group) have been investigated by all-atom molecular dynamics. No predominant conformation was observed in water, but the molecules adopt specific orientations and conformations in the lipid bilayer. As is expected, alkyl chains tend to insert into the hydrophobic core, while charged groups stay at the lipid-water interface. A doxyl group in the middle of the alkyl chain moves up to the interface region, thus preventing adoption of the extended conformation. Compounds with a doxyl group close to the polar head group adopt conformations similar to that of unlabeled perifosine within the first nanoseconds of simulation. When the doxyl group is at the end of alkyl chain, the spin-labeled molecule needs more time to reach equilibrium. These results indicate a considerable effect of the doxyl position within the alkyl chain on its localization in the lipid bilayer and can be extended further to other similar spin probes used in the electron paramagnetic resonance spectroscopy of biological membranes.


Asunto(s)
1,2-Dipalmitoilfosfatidilcolina/química , Membrana Dobles de Lípidos , Fosfolípidos/química , Conformación Molecular , Marcadores de Spin
12.
J Med Chem ; 48(20): 6393-9, 2005 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-16190765

RESUMEN

Alkylphospholipid analogues of perifosine and miltefosine bearing a nitroxide moiety at different positions on an alkyl chain were synthesized as electron paramagnetic resonance (EPR) probes. Their amphiphilic properties were characterized by determining their critical micelle concentration (cmc) and hemolytic activity on erythrocytes both in free and liposomal form. Spin-labeled analogues as membrane components of large unilamellar liposomes containing cholesterol and dicetyl phosphate or in free solution were evaluated using the MTT assay to determine growth inhibition on MT1, MT3, and MCF7 breast cancer cell lines. 4a (IC50 = 56.4 microM) was found to be significantly more active than the perifosine against the MCF-7 cell line. Its high cmc (194.03 microM) and low hemolytic activity shows that its cytotoxic activity might be more specific; therefore, 4a can be an important molecular tool for further EPR investigations.


Asunto(s)
Antineoplásicos/síntesis química , Óxidos N-Cíclicos/síntesis química , Organofosfatos/síntesis química , Fosfolípidos/síntesis química , Fosforilcolina/análogos & derivados , Marcadores de Spin/síntesis química , Tensoactivos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Óxidos N-Cíclicos/química , Óxidos N-Cíclicos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Hemólisis , Humanos , Liposomas , Micelas , Organofosfatos/química , Organofosfatos/farmacología , Fosfolípidos/química , Fosfolípidos/farmacología , Fosforilcolina/síntesis química , Fosforilcolina/química , Fosforilcolina/farmacología , Soluciones , Relación Estructura-Actividad , Tensoactivos/química , Tensoactivos/farmacología
13.
J Med Chem ; 48(6): 2108-14, 2005 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-15771453

RESUMEN

Functionalized xanthine derivatives bearing a nitroxide moiety at the 3- or 8-position were synthesized as electron paramagnetic resonance (EPR) probes. The 8-cyclopentyl-1-propylxanthine derivative 4, spin-labeled at N3 by substitution with a nitroxide-bearing dihydropyrrole moiety, was a potent and selective A(1) adenosine receptor antagonist (K(i) for A(1) 5.5 nM, 1600-fold selectivity vs A(2A), >200-fold vs A(2B), and 310-fold vs A(3) adenosine receptors). 8-(1-Oxyl-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-3-yl)-1,3-dipropylxanthine 10 (K(i) for A(1) 8.2 nM) was similarly potent and selective, while 8-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)-1,3-dipropylxanthine 11 (K(i) for A(1) 160 nM) exhibited significantly lower affinity for A(1) adenosine receptors. 8-[4-(((1-Oxyl-2,2,6,6-tetramethylpiperidin-4-yl)amino)-2-oxoethoxy)phenyl]-1-propylxanthine14, a 3-unsubstituted xanthine derivative, was found to be a potent A(2B) adenosine receptor antagonist (K(i) for A(2B) 48 nM) but also exhibited high affinity for A(1) receptors (K(i) for A(1) 15.7 nM). An X-ray structure of compound 10 was obtained, confirming the proposed structure. The novel spin-labeled A(1)-selective or A(1)/A(2B)-nonselective adenosine receptor antagonists may become useful probes for biophysicochemical investigations of adenosine receptors in their membrane environment.


Asunto(s)
Óxidos N-Cíclicos/síntesis química , Ciclopentanos/síntesis química , Receptores Purinérgicos P1/metabolismo , Marcadores de Spin/síntesis química , Xantinas/síntesis química , Antagonistas del Receptor de Adenosina A1 , Antagonistas del Receptor de Adenosina A2 , Animales , Unión Competitiva , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Línea Celular , Cricetinae , Cricetulus , Cristalografía por Rayos X , Óxidos N-Cíclicos/química , Óxidos N-Cíclicos/farmacología , Ciclopentanos/química , Ciclopentanos/farmacología , Humanos , Técnicas In Vitro , Ligandos , Estructura Molecular , Antagonistas de Receptores Purinérgicos P1 , Ensayo de Unión Radioligante , Ratas , Receptor de Adenosina A1/metabolismo , Receptor de Adenosina A2B/metabolismo , Relación Estructura-Actividad , Xantinas/química , Xantinas/farmacología
14.
Z Naturforsch C J Biosci ; 59(11-12): 880-6, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15666550

RESUMEN

Several novel thiol-reactive clenbuterol analogues were coupled in high yield with bovine serum albumin (BSA). After labelling of unreacted cysteines with maleimide spin label (MiSL), the yield of the coupling reaction was determined by electron paramagnetic resonance (EPR) spectroscopy and spectral analysis. Two spin-probe populations with different mobility states were quantitatively determined. Molecular dynamics was used to model the structure of clenbuterol analogues and spin label conjugated to BSA and recognition of conjugates by anti-clenbuterol antibodies was demonstrated. The recognition of BSA-A, BSA-C and BSA-S conjugates with monoclonal and polyclonal anti-clenbuterol (mCLB-Ab and rCLB-Ab) antibodies was an indication, that chlorine substituents on the aromatic ring of clenbuterol derivatives are not necessary for the binding of antibodies to the conjugates. These results confirmed the importance of the tert-butylamino group as a part of the epitope and contribute to the understanding of the recognition process with anti-clenbuterol antibodies.


Asunto(s)
Agonistas Adrenérgicos beta/química , Clenbuterol/análogos & derivados , Albúmina Sérica Bovina/química , Algoritmos , Secuencia de Aminoácidos , Sitios de Unión , Calorimetría , Clenbuterol/química , Compuestos de Sulfhidrilo
15.
Eur J Pharm Biopharm ; 56(1): 59-66, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12837482

RESUMEN

UV irradiation induces free radical formation in the skin. UV filters and antioxidants can be used for protection. In the present work, the amphiphilic antioxidant ascorbyl palmitate has been investigated and its effectiveness against free radical formation in porcine skin determined with electron paramagnetic resonance (EPR) spectroscopy with a spin trapping technique. 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide (DEPMPO) was used as spin trap. In this study, three different radicals were identified in UV irradiated porcine ear skin: two originated from sulphur centred radicals (SO(3)*), while the third was the carbon-centred acyl (C=O*) radical. Ascorbyl palmitate applied on the skin decreased the level of formation of free radicals. Its effectiveness depended significantly on the carrier system - the type of microemulsion and its concentration, while the time of application had no influence on its effectiveness. Oil in water microemulsions delivered ascorbyl palmitate to the skin significantly better than water in oil microemulsions. In both types of microemulsions, the effectiveness increases at higher concentrations of ascorbyl palmitate.


Asunto(s)
Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/farmacología , Depuradores de Radicales Libres/farmacología , Piel/efectos de los fármacos , Rayos Ultravioleta/efectos adversos , Administración Cutánea , Animales , Ácido Ascórbico/administración & dosificación , Ácido Ascórbico/química , Química Farmacéutica , Portadores de Fármacos , Composición de Medicamentos , Emulsiones , Depuradores de Radicales Libres/administración & dosificación , Depuradores de Radicales Libres/química , Radicales Libres/metabolismo , Técnicas In Vitro , Piel/metabolismo , Piel/efectos de la radiación , Porcinos
16.
Anal Biochem ; 315(2): 202-7, 2003 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-12689830

RESUMEN

The only free thiol group of bovine serum albumin (BSA) was coupled in a high yield with some novel thiol-reactive clenbuterol analogues. The unreacted cysteines were probed with maleimide spin label to determine the yield of the coupling reaction. A novel approach to determining free thiol groups of BSA quantitatively by electron paramagnetic resonance spectroscopy and spectral decomposition without the usual gel-filtration step or extensive dialysis is presented.


Asunto(s)
Clenbuterol/análogos & derivados , Clenbuterol/metabolismo , Albúmina Sérica Bovina/química , Compuestos de Sulfhidrilo/química , Animales , Bovinos , Clenbuterol/química , Espectroscopía de Resonancia por Spin del Electrón , Estructura Molecular , Unión Proteica , Albúmina Sérica Bovina/metabolismo , Marcadores de Spin
17.
Curr Med Chem ; 10(4): 281-90, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12570701

RESUMEN

Clenbuterol and other beta-agonists are commonly misused as repartitioning agents in meat production and as doping substances to improve athletic performance. Numerous reports on food poisoning throughout Europe prompted the EU regulatory offices and FDA to implement a ban on the use of beta-agonists as growth promoters. Several analytical methods have been developed for detecting illegal administration of these compounds, based mainly on chromatography and immunoassay screening. This article deals with the pharmacological aspect of beta-agonists in growth promotion, control of their abuse and methods of analysis.


Asunto(s)
Clenbuterol/metabolismo , Clenbuterol/uso terapéutico , Detección de Abuso de Sustancias/métodos , Trastornos Relacionados con Sustancias/metabolismo , Agonistas Adrenérgicos beta/química , Agonistas Adrenérgicos beta/metabolismo , Agonistas Adrenérgicos beta/uso terapéutico , Animales , Clenbuterol/química , Humanos , Trastornos Relacionados con Sustancias/diagnóstico , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/prevención & control
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