Search results for "pyridine"
showing 10 items of 2516 documents
Anxiolytic-like effects of acute and chronic GABA transporter inhibition in rats.
2002
Acute GABA transporter inhibition can induce anxiolytic-like behaviors. The present analysis addressed whether chronic treatment (23 days via drinking water) with a GABA transporter inhibitor affects rat behavior similar to acute treatment and interferes with additional benzodiazepine-receptor agonistic treatment. Seventy-one rats divided into seven groups were acutely treated with either vehicle, diazepam (2 mg/kg), zolpidem (0.05 mg/kg), tiagabine (19 mg/kg) or chronically with tiagabine with or without acute diazepam or zolpidem. Animals were behaviorally characterized in an elevated plus-maze. None of the treatments induced changes in the activity of the animals. Acute and chronic treat…
m-Chlorophenylpiperazine excites non-dopaminergic neurons in the rat Substantia Nigra and Ventral Tegmental Area by activating serotonin-2c receptors
2001
In vivo electrophysiological techniques were used to study the effect of m-chlorophenylpiperazine, a non-selective serotonin-2C receptor agonist, on the activity of non-dopaminergic neurons in the substantia nigra pars reticulata and the ventral tegmental area of anesthetized rats. Intravenous administration of m-chlorophenylpiperazine (5–320 μg/kg) caused a dose-dependent increase in the basal firing rate of a subpopulation of nigral neurons which do not respond to a footpinch stimulus [P(0) neurons], whereas it did not affect the activity of neurons which are responsive to the footpinch [P(+) neurons]. However, m-chlorophenylpiperazine (5–320 μg/kg) excited all non-dopaminergic neurons sa…
The nicotinic acetylcholine receptor agonist ABT-594 increases FGF-2 expression in various rat brain regions
2000
The present experiments were designed to extend previous work showing that acute intermittent (-)nicotine treatment upregulates the level of fibroblast growth factor-2 (FGF2) mRNA in several rat brain regions, by the use of the nicotinic acetylcholine receptor (nAChR) agonist ABT-594 with preferential selectivity for the alpha4beta2 nAChR subtype. ABT594 treatment led to a well-defined temporal and regional upregulation of FGF-2 mRNA. A double labelling analysis showed that the up-regulation of FGF-2 mRNA involves both neuronal and non-neuronal cells. The effects of ABT-594 on FGF-2 expression were antagonized by the preferential alpha4beta2 antagonist dihydrobetaerythroidine (DHbetaE), but…
Postnatal alterations of the inhibitory synaptic responses recorded from cortical pyramidal neurons in the Lis1/sLis1 mutant mouse
2006
Mutations in the mouse Lis1 gene produce severe alterations in the developing cortex. We have examined some electrophysiological responses of cortical pyramidal neurons during the early postnatal development of Lis/sLis1 mutant mice. In P7 and P30 Lis1/sLis1 neurons we detected a lower frequency and slower decay phase of mIPSCs, and at P30 the mIPSCs amplitude and the action potential duration were reduced. Zolpidem (an agonist of GABAA receptors containing the alpha1 subunit) neither modified the amplitude nor the decay time of mIPSCs at P7 in Lis1/sLis1 neurons, whereas it increased the decay time at P30. The levels of GABAA receptor alpha1 subunit mRNA were reduced in the Lis1/sLis1 brai…
Influence of hormonal treatment on the response of the rat isolated uterus to histamine and histamine receptor agonists.
1992
The response of the isolated uterus to histamine and histamine agonists was investigated in progesterone- and oestrogen-treated rats. The uterine inhibitory responses to histamine and 4-methylhistamine (a histamine H2 receptor agonist) were similar in KCl-contracted uteri from progesterone- and oestrogen-treated rats. The histamine H1 receptor agonist, 2-pyridyl-ethylamine, produced a relaxant response only in progesterone dominant uterus. This was inhibited by the histamine H1 receptor antagonist. In the rat isolated uterus which was not preconstricted by KCl, neither histamine, 4-methylhistamine, nor 2-pyridyl-ethylamine produced any effect in the presence or absence of ranitidine. Raniti…
Bis(oxazoline) Lewis Acid Catalyzed Aldol Reactions of PyridineN-Oxide Aldehydes—Synthesis of Optically Active 2-(1-Hydroxyalkyl)pyridine Derivatives…
2006
A new, short, and simplified procedure for the synthesis of optically active pyridine derivatives from pro-chiral pyridine-N-oxides is presented. The catalytic and asymmetric Mukaiyama aldol reaction between ketene silyl acetals and 1-oxypyridine-2-carbaldehyde derivatives catalyzed by chiral copper(II)-bis(oxazoline) complexes gave optically active 2-(hydroxyalkyl)- and 2-(anti-1,2-dihydroxyalkyl)pyridine derivatives in good yields and diastereoselectivities, and in excellent enantioselectivities-up to 99 % enantiomeric excess. As a synthetic application of the developed method, a full account for the asymmetric total synthesis of a nonnatural indolizine alkaloid is provided.
On the influence of the acid-base character of catalysts on the oxidative dehydrogenation of alkanes
1996
Vanadium oxides supported on metal oxide, i.e. Al2O3, MgO and Mg-Al mixed oxide, and V-containing microporous materials (VAPO-5 and MgVAPO-5) have been tested in the oxidative dehydrogenation of C2-C4 alkanes. In all cases, tetrahedral vanadium species (isolated and/or associated) were mainly observed from51V-NMR and diffuse reflectance spectroscopies. The reducibility of V5+-species, determined from the onset-reduction temperature, decreases as follows: VOx/AL > VAPO-5 > MgVAPO-5 =VOx/MG > VOx/MG + AL. The acid character of catalysts, determined from the FTIR spectra of pyridine adsorbed, decreases as: MgVAPO-5 > VOx/AL > VAPO-5 > VOx/MG + AL > VOx/MG. A similar trend between V-reducibilit…
The Allyl Ester as Carboxy-Protecting Group in the Stereoselective Construction of Neuraminic-Acid Glycosides
1988
The application of the allyl-ester moiety as protecting principle for the carboxy group of N-acetylneuraminic acid is described. Peracetylated allyl neuraminate 2 is synthesized by reacting the caesium salt of the acid 1 with allyl bromide. Treatment of 2 with HCl in AcCl or with HF/pyridine gives the corresponding 2-chloro or 2-fluoro derivatives 3 and 4, respectively (Scheme 1). In the presence of Ag2CO3, the 2-chloro carbohydrate 3 reacts with di-O-isopropylidene-protected galactose 5 to give the 2–6 linked disaccharide with the α-D-anomer 6a predominating (α-D/β-D = 6:1; Scheme 2). Upon activation of the 2-fluoro derivative 4 with BF3 · Et2O, the β-D-anomer 6b is formed preferentially (…
Synthesis and biological activities of a new class of heat shock protein 90 inhibitors, designed by energy-based pharmacophore virtual screening
2013
The design through energy-based pharmacophore virtual screening has led to aminocyanopyridine derivatives as efficacious new inhibitors of Hsp90. The synthesized compounds showed a good affinity for the Hsp90 ATP binding site in the competitive binding assay. Moreover, they showed an excellent antiproliferative activity against a large number of human tumor cell lines. Further biological studies on the derivative with the higher EC50 confirmed its specific influence on the cellular pathways involving Hsp90.
Off-line coupling of multidimensional immunoaffinity chromatography and ion mobility spectrometry: A promising partnership.
2015
The extreme specificity of immunoaffinity chromatography (IAC) columns coupled to the high sensitivity of ion mobility spectrometry (IMS) measurements makes this combination really useful for rapid, selective, and sensitive determination of a high variety of analytes in different samples. The capabilities of the IAC-IMS coupling have been highlighted under three different scenarios: (i) multiclass residue analysis using a single IAC column, (ii) multiclass residue analysis using stacked IAC columns, and (iii) isomer analysis. In the first case, the determination of three strobilurin fungicides - azoxystrobin, picoxystrobin, and pyraclostrobin - in water and strawberry juice was considered, …