Search results for "Organic Chemical"

Synthese und pharmakologische Wirkung von carbocyclischen Muskarinanalogen

1974

Als carbocyclische Muskarinanaloga wurden das (3-Hydroxycyclopentylmethyl)trimethyl-ammonium-jodid und dessen Acetat dargestellt und am isolierten Ileum des Meerschweinchens untersucht. Synthesis and Pharmacological Activity of Carbocyclic Analogs of Muscarine As carbocyclic analogs of muscarine (3-hydroxycyclopentylmethyl)trimethylammonium iodide and (3-acetoxycyclopentylmethyl)trimethylammonium iodide were synthesized and tested on the isolated guinea pig ileum.

Synthesis of a Tyr3-octreotate conjugated closo-carborane [HC2B10H10]: a potential compound for boron neutron capture therapy

2003

Abstract A novel Tyr 3 -octreotate conjugated closo -carborane as a potential compound for boron neutron capture therapy was obtained via Fmoc solid phase peptide synthesis. The boron cluster [C 2 B 10 H 11 ] was introduced through the reaction of 6,9-bis(acetonitrile)decaborane and 5-hexynoic acid yielding a new closo -carborane conjugated carboxylic acid which was coupled subsequently with solid phase conjugated Tyr 3 -octreotate. The final boron-containing peptide was purified by preparative reverse phase HPLC and structural identity was proved applying MALDI-TOF mass spectrometry.

Versuche zur Herstellung linolsäurearmen Ölsäureesters über eine Hydrierung mit Palladium

1980

Uber eine Hydrierung mit Palladium auf Aktivkohle konnen geringe Gehalte an Linolsaure in Gegenwart eines hohen Olsaureuberschusses recht selektiv reduziert werden. Der Linolsauregehalt eines Fettsauremethylestergemisches wurde von 10% auf 2% gesenkt, dabei entstanden 3% cis-, 4% trans-Monoenfettsauren sowie 1% Stearinsaure. The Preparation of Oleic Ester with Reduced Linoleic Acid Content by Hydrogenation with Palladium By hydrogenation with palladium on charcoal low contents of linoleic acid can be reduced quite selectively in the presence of an excess of oleic acid ester. In a mixture of fatty acid methylesters the content of linoleic acid was reduced from 10% to 2% with the formation of…

Phosphonium-Boronate Amino Acid Derivatives as Fluoride Pincers for 18F-Labelling

2015

The synthesis of phosphonium-boronate amino acid derivatives was achieved by quaternization of o-boronatophenylphosphine with iodo-amino acid derivatives. Preliminary radiolabelling studies demonst...

Monte Carlo Simulations of Parallel Charged Platelets as an Approach to Tactoid Formation in Clay

2013

The free energy of interaction between parallel charged platelets with divalent counterions has been calculated using Monte Carlo simulations to investigate the electrostatic effects on aggregation. The platelets are primarily intended to represent clay particles. With divalent counterions, the free energy for two platelets or two tactoids (clusters of parallel platelets) shows a minimum at a short separation due to the attraction caused by ion-ion correlations. In a salt-free system, the free energy of interaction has a long-range repulsive tail beyond the minimum. The repulsion increases for tactoids with larger aggregation numbers, whereas the depth of the free-energy minimum is graduall…

Pressure- and temperature-induced valence tautomeric interconversion in a o-dioxolene adduct of a cobalt-tetraazamacrocycle complex

2001

An electronic switch at the molecular level has been realized by using a class of ionic compounds of the formula [Co(L)(diox)]Y (L = tetraazamacrocyclic ligand, Y = mononegative anion). Such compounds undergo temperature- and pressure-induced intramolecular one-electron transfer equilibria. The transition temperature of interconversion varies with the nature of the counterions Y (Y = PF6, BPh4, I). Surprisingly the effect of the anion on the transition temperature is not only governed by its volume but also by its coulombic interaction.

A M�ssbauer and ESR study of LiNbO3-Fe2O3 for low Fe2O3 concentrations

1989

Samples of the system LiNbO3-Fe2O3 prepared by water quenching and by the double-roller quenching method in the range up to 24 mol% Fe2O3 were investigated by Mossbauer and ESR spectroscopy. In the water quenched samples up to 11 mol% Fe2O3 only the Fe3+ and the Fe2+ valence states could be detected. The Fe2+ concentration decreased with increasing Fe2O3 content. Above 11 mol% Fe2O3 magnetically split Mossbauer spectra indicated the presence of Fe2O3 clusters. The isomer shift values of Fe3+ as a function of Fe2O3 concentration showed jumps at 6 and 11 mol% Fe2O3, whereas no significant changes could be detected in the quadrupole splitting values. The ESR data already exhibited the existenc…

Isobaric Vapor−Liquid Equilibria for Water + Acetic Acid + Potassium Acetate

2004

Isobaric vapor−liquid equilibria for water + acetic acid + potassium acetate at different salt concentrations as well as for solvent + potassium acetate binary mixtures have been obtained at 100 kPa. Potassium acetate is more effective in the salting-out effect (on water) than lithium and sodium acetates. The eNRTL-CT model, which is a combination of electrolyte nonrandom two-liquid and chemical theory models, has been used to fit the experimental data. The binary parameters of the model have been obtained from the experimental binary vapor−liquid equilibria which have been used to suitably reproduce the vapor−liquid equilibria (VLE) for water + acetic acid + potassium acetate ternary syste…

Synthesis, characterization and antimicrobial activity of palladium(II) complexes with some alkyl derivates of thiosalicylic acids: Crystal structure…

2012

Abstract S-Alkyl (R = benzyl, methyl, ethyl, propyl and butyl) derivatives of thiosalicylic acid and the corresponding palladium(II) complexes were prepared and their structures were proposed on the basis of infrared, 1H and 13C NMR spectroscopy. The cis geometrical configurations of the isolated complexes were proposed on the basis of an X-ray structural study of the bis(S-benzyl-thiosalicylate)–palladium(II), [Pd(S-bz-thiosal)2] complex. Antimicrobial activity of the tested compounds was evaluated by determining the minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) in relation to 26 species of microorganisms. The tested ligands, with a few exceptions, sho…

1988

Negatively charged lipid molecules were converted into polymerizable lipids by introduction of polymerizable mono- or bifunctional counterions. As an attempt to mimic the cytoskeleton of biomembranes, unsymmetrical polymeric vesicles were prepared, where the polyelectrolyte is attached either only to the inner or to the outer bilayer surfaces. Polymerizable cations were introduced to the outer surface of preformed small unilamellar vesicles via ion-exchange. The outer counterions of vesicles bearing polymerizable counterions at both sides of the membrane were replaced by Na+. Polymerization of these systems leads to unsymmetrical vesicles. The introduction, separation and polymerization of …