Search results for "amine"
showing 10 items of 7299 documents
Dual Hydrogen Bond - Enamine Catalysis Enables a Direct Enantioselective Three-Component Domino Reaction
2011
A dual system, composed of an enantioselective enamine catalyst and a multiple-hydrogen-bond catalyst achieves the three-component enantioselective aldehyde—nitroalkene—aldehyde domino reaction using either two similar or two different aldehydes.
5-(4-Fluoro-phen-yl)-4-(4-pyrid-yl)-1,3-oxazol-2-amine.
2010
In the crystal structure of the title compound, C14H10FN3O, the plane of the isoxazole ring makes dihedral angles of 35.72 (9) and 30.00 (9)°, respectively, with those of the 4-fluorophenyl and pyridine rings. The plane of the 4-fluorophenyl ring makes a dihedral angle of 45.85 (8)° with that of the pyridine ring. The crystal structure is stabilized by intermolecular N—H...N hydrogen bonding. The two types of hydrogen bonds result in two chains, extending along the a axis, which are related by centres of symmetry.
N-{4-[3-(4-Fluorophenyl)pyrido[2,3-b]pyrazin-2-yl]-2-pyridyl}isopropylamine
2009
In the crystal structure of the title compound, C21H18FN5, the pyridopyrazine ring system forms dihedral angles of 33.27 (7) and 48.69 (9)° with the 4-fluorophenyl and pyridine ring, respectively. The dihedral angle of the 4-fluorophenyl and pyridine rings is 57.45 (8)°. The crystal packing is characterized by an intermolecular N—H...N hydrogen bond.
4-(4-Fluorophenyl)-3-(pyridin-4-yl)-1-(2,4,6-trichlorophenyl)-1H-pyrazol-5-amine
2012
In the title compound, C20H12Cl3FN4, the pyrazole ring forms dihedral angles of 47.51 (9), 47.37 (9) and 74.37 (9)° with the directly attached 4-fluorophenyl, pyridine and 2,4,6-trichlorophenyl rings, respectively. Only one of the two amino H atoms is involved in hydrogen bonding. The crystal packing is characterized by N—H...N hydrogen bonds, which result in infinite chains parallel to the c axis.
4-(4-Fluorophenyl)-1-phenyl-3-(pyridin-4-yl)-1H-pyrazol-5-amine
2012
In the title compound, C20H15FN4, the pyrazole ring forms dihedral angles of 43.51 (6), 39.95 (6) and 32.23 (6)° with the directly attached 4-fluorophenyl, pyridine and phenyl rings, respectively. The crystal packing is stabilized by intermolecular N—H...N and N—H...F hydrogen bonds.
Nitrate Encapsulation within the Cavity of Polyazapyridinophane. Considerations on Nitrate−Pyridine Interactions
2010
Interaction of nitrate anions with a cyclophane (L) containing two pyridine units connected to two diethylenetriamine bridges through methylene positions is reported both in pure water and in the solid state. The crystal structure of [H4L](NO3)4 shows that one of the nitrate anions resides in the macrocyclic cavity forming two sets of bifurcated hydrogen bonds with the four protonated amino groups of the macrocycle. This anion is symmetrically placed in the middle of the pyridine rings with distances between its nitrogen atom and the centroids of the ring of 3.58 A. Despite this location, calculations by theoretical analysis were carried out to confirm whether the stabilizing effect is due …
Self-assembly by co-ordination and strong hydrogen bonding. X-ray crystal structures of a dimeric trisodium complex of a new acidic complexing ligand…
1993
Abstract The new acidic complexing ligand triethanolamine-O,O,O-triacetic acid, 3, is synthesized by reaction of triethanolamine with chloroacetic acid in the presence of sodium tert-butoxide. The resulting Na complex, 4, and its dihydrate, 5, contain two ligand molecules, both with one Na+ ion interaction and both co-ordinated to a third, central, Na+ ion. In addition the acidic ligands are hydrogen bonded to each other, like carboxylic acids, and in 4, by three crystallographically symmetric hydrogen bonds, while in 5, due to the breakdown of symmetry, two normal and one crystallographically symmetrical hydrogen bond. Inside this extraordinary dimeric assembly (a pseudo-cryptate) are the …
Study of supramolecular structures released from the cell wall of Candida albicans by ethylenediamine treatment
1996
Candida albicans cell wall components were analyzed by ethylenediamine (EDA) treatment. Based on their different solubility properties, the cell wall components produced three fractions (A, B, and C). Fractions B (EDA-soluble, water-insoluble) and C (EDA-insoluble) contained glucan, chitin, and protein in different proportions. After zymolyase (mainly a beta-glucanase complex) or chitinase treatment of fractions B and C, more polysaccharides and proteins were solubilized by a second EDA treatment, suggesting that the solubility of the polymers in EDA depends on the degree of polymer interactions. Western blot analysis using two monoclonal antibodies (1B12 and 4C12) revealed electrophoretic …
Guanosine Protects Glial Cells Against 6-Hydroxydopamine Toxicity
2014
Increasing body of evidence indicates that neuron-neuroglia interaction may play a key role in determining the progression of neurodegenerative diseases including Parkinson’s disease (PD), a chronic pathological condition characterized by selective loss of dopaminergic (DA) neurons in the substantia nigra. We have previously reported that guanosine (GUO) antagonizes MPP+-induced cytotoxicity in neuroblastoma cells and exerts neuroprotective effects against 6-hydroxydopamine (6-OHDA) and beta-amyloid-induced apoptosis of SH-SY5Y cells. In the present study we demonstrate that GUO protected C6 glioma cells, taken as a model system for astrocytes, from 6-OHDA-induced neurotoxicity. We show tha…
Evaluation of enantioselective binding of basic drugs to plasma by ACE.
2007
The present paper deals with the evaluation of the stereoselective binding of antihistamines (brompheniramine, chlorpheniramine, hydroxyzine, orphenadrine and phenindamine), phenothiazines (promethazine and trimeprazine) and a local anesthetic (bupivacaine) to human plasma proteins. Since all of them are drugs highly bound to proteins, a methodology to determine the bound fraction of each drug enantiomer was proposed. This methodology includes the incubation of samples containing plasma and racemic drug, ultrafiltration of the mixture and the chiral separation of enantiomers in the bound drug fraction using affinity EKC (AEKC)-partial filling technique and HSA as chiral selector. The result…