[Assessment of a Tiapride solution for its administration through continuous intravenous perfusion]. / Estudio de estabilidad de tiaprida en disolución para administración en perfusión intravenosa continua.

OBJECTIVES: Tiapride is a substituted benzamide classified as an atypical neuroleptic. To our knowledge, there are no published data on its stability prepared as a continuous intravenous infusion. The current study analysed its stability in two different infusion solutions and concentrations over 48 hours. METHOD: Triplicate samples of tiapride were prepared in 0.9% sodium chloride and in 5% dextrose solutions at final concentrations of 1 and 2 mg/ml. Samples were collected in glass bottles without photoprotection and at room temperature (25 ± 2 °C). Sampling times at 0, 1, 3, 6, 12, 24 and 48 hours included a visual inspection for colour changes and appearance of precipitation as well as pH determination. Tiapride was quantified at selected times by mass spectrometry using high-performance liquid chromatography. Concentration values in the samples corresponding to 0 hours were given a reference value of 100%. Concentrations in subsequent samples greater than 90% were considered stable. RESULTS: No colour change or precipitation was observed during the study period. pH values ranged between 0.1 and 0.4 units. At 48 hours, the concentration of remaining tiapride in sodium chloride 1 mg/ml and 2 mg/ml was 93.8% and 91.6%, respectively. That in 5% dextrose 1 mg/ml and 2 mg/ml was 96.8% and 94.1%, respectively. CONCLUSION: Dilutions of tiapride in 0.9% sodium chloride and in 5% dextrose solution, at concentrations of 1 mg/ml and 2 mg/ml, in glass bottles and at room temperature were stable both physically and chemically during 48 hours.

Síntesis y evaluación de nuevos inhibidores de las HDAC / Synthesis and evaluation of new HDAC inhibitors

La acetilación de residuos de lisina en las histonas está mediada por las enzimas denominadas histona acetiltransferasas (HAT). Los grupos acetilo son eliminados de las e-N-acetil-lisinas por la actividadde las histonas desacetilasas (HDAC). El balance entre las actividades opuestas de las HAT y las HDAC regula el estado de acetilación de las histonas. Este tipo de modificaciones regulan en la célula procesos fundamentales clave en respuesta a señales extracelulares. En general, altos niveles de acetilación (hiperacetilación) se asocian a un incremento de la actividad transcripcional, mientras que bajos niveles de acetilación (hipoacetilación) se asocian a la represión de la expresión genética. Actualmente se conocen diversos tipos de inhibidores de las HDAC que pueden reactivar la expresión genética e inhibir el crecimiento de las células tumorales, por lo que se investiga su uso en el tratamiento frente al cáncer. Sería deseable identificar nuevos inhibidores de las enzimas HDAC para su utilización en el tratamiento o profilaxis de enfermedades en las que la inhibición de dichas enzimas HDAC está implicada. Se han obtenido 10 nuevos inhibidores de las HDAC y se ha evaluado su actividad frente a HDAC aislada. Se discute la importancia de las modificaciones realizadas en el espaciador(AU)

Lysine residues acetylation on histones is mediated by histone acetyltransferase (HAT). The acetyl groups are removed from e-N-acetyl-lysine by the histone deacetylase (HDAC) activity. The balance between the HATs and HDACs activities regulates the histone acetylation status. Such changes regulate key processes in the cell in response to extracellular signals. Mostly, high levels of acetylation(hyperacetylation) are associated with increased transcriptional activity. Low levels of acetylation (hypoacetylation) are associated with repression of gene expression. Currently, different types of HDAC inhibitors are known to reactivate gene expression and inhibit tumor cell growth. We aim at identifying novel HDAC inhibitors for the treatment or prophylaxis of cancer diseases. Ten new HDAC inhibitors have been obtained and their potency as HDAC inhibitors has been evaluated. A structure-activity relationship discussion has been focused on the structural changes made in the spacer(AU)

Short, highly efficient syntheses of protected 3-azido- and 4-azidoproline and their precursors.

[structure: see text] An improved synthesis of protected cis- and trans-3-azido-L-proline and cis- and trans-4-azido-L- and -D-proline is reported. These compounds have been synthesized from the corresponding hydroxyproline precursors using diphenylphosphoryl azide under Mitsunobu conditions. Short, highly efficient syntheses of these precursors are described, based on a new lactone-opening reaction and p-nitrobenzoate hydrolysis under very mild conditions.

Mild and selective sodium azide mediated cleavage of p-nitrobenzoic esters.

[reaction: see text] A mild and selective cleavage of p-nitrobenzoic esters by sodium azide in methanol is reported. This new methodology is mild enough for use with acid- or base-sensitive compounds. No elimination byproducts are formed. Fmoc- and trifluoroacetyl-amino protecting groups, benzyl esters, and ethyl esters remain unaffected. Less reactive compounds are discussed in terms of steric factors, and yields are increased by altering the azide solvation.

CCB, a novel specific kappa opioid agonist, which discriminates between opioid and sigma 1 recognition sites.

CCB, 6,11-Dimethyl-1,2,3,4,5,6-hexahydro-3-([2'-methoxycarbonyl-2'-(4- chlorophenyl)cyclopropyl]methyl)-2,6-methano-3-benzazocin-8-ol, displays specificity and very high affinity for kappa opioid receptor types (Ki = 0.41 +/- 0.19 nM). In contrast to other kappa opioid agonists, CCB is also selective with respect to sigma 1 sites (Ki = 1,050 +/- 55 nM). CCB displays antinociceptive and sedative effects in the mouse comparable to those of U50,488H and morphine. Naltrexone fully antagonizes these effects. The sedative effects of CCB are blocked in mice pretreated with naltrexone or nor-BNI. CCB and U50,488H produce a superimposable diuresis in rats. Naltrexone and nor-BNI, both are effective in antagonizing the effect. CCB does not produce any stereotyped behavior or ataxia in the behavioral assay in doses up to 40 mg/kg s.c. These findings suggest that CCB might be a useful tool to investigate the physiological role of kappa opioid receptors.