Search results for "Ethylamines"
showing 10 items of 47 documents
Self-assembly of 3,5-bis(ethoxycarbonyl)pyrazolate anions and ammonium cations of β-phenylethylamine or homoveratrylamine into hetero-double-stranded…
2009
Hydrogen-bonded double-stranded hetero-helices are formed when reacting sodium 3,5-bis(ethoxycarbonyl)pyrazolate with beta-phenethylammonium or homoveratrylammonium chloride, in which one of the strands is defined by the ammonium cations and the other one by the pyrazolate anions.
Chiral Monofluorobenzyl Carbanions: Synthesis of Enantiopure β‐Fluorinated β‐Phenylethylamines
2011
The preparation of a stabilized monofluorobenzyl carbanion by means of a remote homochiral sulfinyl group and its completely stereoselective reactions with N-p-tolylsulfinylimines are described. The use of these reactions followed by the simultaneous removal of both chiral auxiliaries with tBuLi, which occurs without epimerization at the benzylic position, provides the quickest entry to enantiomerically pure β-fluorinated β-phenylethylamines.
Calculation of the relative basicities of methylamines in solution
1990
Abstract The relative basicities in solution of the methylamines have been calculated using the model of Miertus, Scrocco and Tomasi to describe the solvent effect. The surface of the cavity is defined with the GEPOL method. The ab initio calculations have been performed using a 4-31G basis set. The relative order is reproduced using a combination of the gas-phase proton affinities obtained with quantum-mechanical methods by Eades, Weil, Dixon and Douglass and the solvation values obtained by us. The results seem to point out that the irregular order is not due to solvent but to basis-set effects.
Storage and release of false transmitters after infusion of (+)- and (?)-?-methyldopamine
1971
Rabbits were given an infusion of 10 mg/kg (−)- or 30 mg/kg (+)-α-methyldopamine and killed after 135 min. The noradrenaline content of the heart was decreased to 26±5 and 34±2%, respectively, of the control value. After infusion of the (+)-isomer the missing noradrenaline was replaced by (−)-α-methylnoradrenaline. Electrical stimulation of the sympathetic nerves or infusion of acetylcholine plus atropine caused an output of noradrenaline and (−)-α-methylnoradrenaline from the isolated heart. The two amines were released in the same proportion as they were stored in the heart and the total output of both amines equalled the output of noradrenaline from control hearts. Nerve stimulation caus…
Detection of the synthetic drug 4-fluoroamphetamine (4-FA) in serum and urine.
2010
Abstract 4-Fluoroamphetamine (4-FA) was detected in the blood and urine of two individuals suspected for driving under the influence (DUI). The test for amphetamines in urine subjected to immunoassay screening using the CEDIA DAU assay proved positive. Further investigations revealed a 4-FA cross-reactivity of about 6% in the CEDIA amphetamine assay. 4-FA was qualitatively detected in a general unknown screening for drugs using GC/MS in full scan mode. No other drugs or fluorinated phenethylamines were detected. A validated GC/MS method was established in SIM mode for serum analysis of 4-FA with a limit of detection (LOD) of 1 ng/mL and a lower limit of quantification (LLOQ) of 5 ng/mL. Int…
The gut microbiota: An emerging risk factor for cardiovascular and cerebrovascular disease
2018
Commensal gut microbiota have recently been implicated in cardiovascular disease (CVD) and cerebrovascular disease. Atherosclerotic plaque formation depends on the colonization status of the host. In addition to host nutrition and the related microbiota-dependent metabolic changes, activation of innate immune pathways triggers the development of atherosclerosis and supports arterial thrombosis. Gnotobiotic mouse models have uncovered that activation of Toll-like receptor-2 by gut microbial ligands supports von Willebrand factor-integrin mediated platelet deposition to the site of vascular injury. Depending on nutritional factors, the microbiota-derived choline-metabolite trimethylamine N-ox…
Comparison of the performance of butanol and pentanol as modifiers in the micellar chromatographic determination of some phenethylamines
2000
Abstract A procedure was developed for the determination of several phenethylamines (amphetamine, arterenol, ephedrine, phenylephrine, phenylpropanolamine, mephentermine, methoxyphenamine, pseudoephedrine and tyramine), using micellar mobile phases of sodium dodecyl sulfate (SDS), a C18 column and UV detection. The drugs were eluted at short retention times with conventional acetonitrile–water or methanol–water mobile phases. In contrast, in the micellar system, they were strongly retained due to association with the surfactant adsorbed on the stationary phase, and needed the addition of butanol or pentanol to be eluted from the column. These modifiers allowed a simple way of controlling th…
Synthesis and inhibitory activity of dimethylamino-chalcone derivatives on the induction of nitric oxide synthase.
2002
A series of nine dimethylamino-chalcone derivatives (1,3-diaryl-propenones) was synthesized and screened as potential inhibitors of NO and PGE(2) production in the RAW 264.7 macrophage cell line. 4-Dimethylamino-2',5'-dimethoxychalcone (6) was found to be the most potent and dual inhibitor (IC(50s) in the submicromolar range) of NO and PGE(2) production. 2',6'-Dimethoxylation appeared to be an effective requirement for selective and potent inhibition of nitric oxide synthase induction as it was confirmed by Western blot analysis. Chalcone (6) at 25 mg kg(-1) by oral route, inhibited significantly the formation of oedema in the carrageenan-induced model of inflammation in mice.
Detection and characterization of emerging psychoactive substances by ion mobility spectrometry
2014
Rapid detection and identification of novel psychoactive substances (NPS) continues to present significant analytical challenges to forensic and analytical chemists. Ion mobility spectrometry (IMS) has been traditionally considered as the analytical technique of choice to detect illicit drugs in security points in airports, borderlines and customs. Databases of the reduced mobility (K0 ) values of illicit drugs are available in the scientific literature and they should be completed with data of emerging designer drugs. In this paper, we have evaluated the effect of different measurement conditions and determined the K0 values of an important number of NPS including different families; such …
Chromatographic analysis of phenethylamine-antihistamine combinations using C8, C18 or cyano columns and micellar sodium dodecyl sulfate-pentanol mix…
2001
The chromatographic behaviour of binary and ternary mixtures of several phenethylamines (phenylephrine, phenylpropanolamine, ephedrine, pseudoephedrine and methoxyphenamine) and antihistamines (pheniramine, carbinoxamine, doxylamine, chlorpheniramine, dexchlorpheniramine, dexbrompheniramine, diphenhydramine, tripolidine, azatadine and phenyltoloxamine), found in cough-cold pharmaceutical preparations, was studied using C8, C18 and cyano columns, micellar mobile phases of sodium dodecyl sulfate (SDS) and pentanol and UV detection. Using a C8 column and mobile phases of 0.05 mol l-1 SDS-6% v/v pentanol or 0.15 mol l-1 SDS-2% v/v pentanol at pH 7, more than 30 different phenethylamine-antihist…