Search results for " Amin"
showing 10 items of 944 documents
Structure-activity relationship of dopaminergic halogenated 1-benzyl-tetrahydroisoquinoline derivatives
2009
Two series of halogenated 1-benzyl-7-chloro-6-hydroxy-tetrahydroisoquinolines were prepared to explore the influence of each series on the affinity for dopamine receptors. All the compounds displayed a high affinity for D(1)-like and/or D(2)-like dopamine receptors in striatal membranes, although they were unable to inhibit [(3)H]-dopamine uptake in striatal synaptosomes. The halogen placed on the benzylic ring in 1-benzyl-THIQs, compounds of the series 1, 2'-bromobenzyl derivatives with K(i) values into the nanomolar range, and the series 2, 2',4'-dichlorobenzyl-THIQ homologues, proves to be an important factor to modulate affinity at dopamine receptor. (C) 2009 Elsevier Masson SAS. All ri…
Iron Induces Proliferation and Morphogenesis in Primmorphs from the Marine SpongeSuberites domuncula
2002
Dissociated cells from marine demosponges retain their proliferation capacity if they are allowed to form special aggregates, the primmorphs. On the basis of incorporation studies and septin gene expression, we show that Fe3+ ions are required for the proliferation of cells in primmorphs from Suberites domuncula. In parallel, Fe3+ induced the expression of ferritin and strongly stimulated the synthesis of spicules. This result is supported by the finding that the enzymatic activity of silicatein, converting organosilicon to silicic acid, depends on Fe3+. Moreover, the expression of a scavenger receptor molecule, possibly involved in the morphology of spicules, depends on the presence of Fe3…
The fnr Gene of Bacillus licheniformis and the Cysteine Ligands of the C-Terminal FeS Cluster
1998
Many of the O2-responsive gene regulators of bacteria are members of the fumarate nitrate reductase-cyclic AMP receptor protein family of transcriptional regulators (12, 13, 15, 17) with predicted structures similar to those of the cyclic AMP receptor protein (11). The Fnr (stands for fumarate nitrate reductase regulator) protein from Escherichia coli (FnrEc) controls the expression of a variety of genes, mainly of anaerobic respiration and metabolism (5, 13). It contains a N-terminal cluster of three essential cysteine residues which are supposed to bind together with Cys122 a [4Fe 4S]2+ cluster which is required for O2 sensing (4, 7, 8, 10, 16). A wide variety of gram-negative bacteria co…
Organocatalysts Fold to Generate an Active Site Pocket for the Mannich Reaction
2017
Catalysts containing urea, thiourea and tertiary amine groups fold into a three-dimensional organized structure in solution both in the absence as well as in the presence of substrates or substrate analogues, as indicated by solution NMR and computational studies. These foldamer catalysts promote Mannich reactions with both aliphatic and aromatic imines and malonate esters. Hammett plot and secondary kinetic isotope effects provide evidence for the C-C bond forming event as the turnoverlimiting step of the Mannich reaction. Computational studies suggest two viable pathways for the C-C bond formation step, differing in the activation modes of the malonate and imine substrates. The results sh…
Spaghetti Enriched with Inulin: Effect of Polymerization Degree on Quality Traits and α-Amylase Inhibition.
2022
Inulin is considered a dietary fiber and represents a noteworthy ingredient for food biofortification due to its health effects and its neutral taste. The aim of the work was the evaluation of the quality of pasta produced using whole-meal flours of two ancient Sicilian landraces (Senatore Cappelli-CAP and Timilia—TIM) fortified with two types of inulin (long-chain topinambur inulin IT and low-chain chicory inulin IC), at two different levels of substitution (2 and 4%) to evaluate its possible effect on α-amylase inhibition. The color indices L* and a* were mainly influenced by cultivars, while IT improved the sensory attributes, mainly the elasticity sensation, and influenced l…
Study of aromatic nucleophilic substitution with amines on nitrothiophenes in RTILs: are the different effects on the behavior of para-like and orto-…
2006
The kinetics of the nucleophilic aromatic substitution of some 2-L-5-nitrothiophenes (para-like isomers) with three different amines (pyrrolidine, piperidine, and morpholine) were studied in three roomtemperature ionic liquids ([bmim][BF4], [bmim][PF6], and [bm2im][BF4], where bmim ) 1-butyl-3- methylimidazolium and bm2im ) 1-butyl-2,3-dimethylimidazolium). To calculate thermodynamic parameters, a useful instrument to gain information concerning reagent-solvent interactions, the reaction was carried out over the temperature range 293-313 K. The reaction occurs faster in ionic liquids than in conventional solvents (methanol, benzene), a dependence of rate constants on amine concentration sim…
Determination of basic strenght of aliphatic amines through ion pair formation in some ionic liquid solutions
2010
To have an evaluation of the basic strength of aliphatic amines in ionic liquid solution, the stability constants relevant to the formation of amine/p-nitrophenol ion pairs were determined in different ionic liquids at 298 K. In particular, aliphatic (pyrrolidinium) and aromatic (imidazolium) ionic liquids were used. Imidazolium ions, bmim(+) and bm(2)im(+), having different hydrogen bond donor abilities were taken into account. Anions were chosen ([BF(4)(-)], [PF(6)(-)], and [NTf(2)(-)]; where NTf(2) = bis(trifluoromethansulfonyl)imide) showing different shape, size, and coordination ability. Several primary, secondary (cyclic or not), and tertiary amines were used to study the effect of a…
Pressor amines in coronary artery bypass grafting procedure with and without the use of extracorporeal circulation
2017
Wstęp: Operacje rewaskularyzacji mięśnia sercowego są najczęściej wykonywanymi procedurami w praktyce kardiochirurgicznej. Rozwój technik pomostowania tętnic wieńcowych bez użycia krążenia pozaustrojowego spowodował, iż modyfikacjom uległy również techniki znieczulenia. W prowadzeniu znieczulenia do zabiegów typu OPCA B anestezjolog musi szczególnie szybko reagować na częste, czasem nieprzewidywalne zmiany sytuacji hemodynamicznej. Cel pracy: Celem pracy było porównanie zastosowania amin presyjnych wśród pacjentów poddanych chirurgicznej rewaskularyzacji mięśnia sercowego z krążeniem pozaustrojowym i bez niego. Materiał i metody: Badanie miało charakter retrospektywny. Badaniem objęto 80 ch…
Monovalent cation conductance in Xenopus laevis oocytes expressing hCAT-3
2005
hCAT-3 (human cationic amino acid transporter type three) was investigated with both the two-electrode voltage clamp method and tracer experiments. Oocytes expressing hCAT-3 displayed less negative membrane potentials and larger voltage-dependent currents than native or water-injected oocytes did. Ion substitution experiments in hCAT-3-expressing oocytes revealed a large conductance for Na + and K + . In the presence of l-Arg, voltage-dependent inward and outward currents were observed. At symmetrical (inside/outside) concentrations of l-Arg, the conductance of the transporter increased monoexponentially with the l-Arg concentrations; the calculated Vmax and KM values amounted to 8.3 AS and…
New Insights into the complexation of lead(II) by 1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane (DOTAM): structural, thermodynami…
2007
The lead(II) coordination properties of the tetrapodal ligand DOTAM [1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraaza-cyclododecane] have been investigated both in the solid state and in solution in order to ascertain the stereoactivity of the lone pair and to rationalize the structural effects of a cyclen-based scaffold on the metal uptake kinetics. The crystal structure of the free base shows that the pendant acetamide groups are not equivalent: two are folded over the macrocycle and maintained by an intramolecular hydrogen bond involving an amide hydrogen atom and a neighboring tertiary amine of the cyclen ring, while the other two are extended and point away from the macrocyclic cav…