Hydroxyethyl Ammonium Acetate Research Articles

Solubility Behavior of Calcium Sulfate Dihydrate (Gypsum) in an Aqueous Sodium Chloride System in the Presence of Hydroxyalkyl Ammonium Acetate Ionic Liquids Additives: Morphology Changes and Physicochemical Solution Properties at 35 °C

Dissolution characteristics of calcium sulfate dihydrate (gypsum, CaSO4·2H2O) in brines have been investigated in the presence of hydroxyalkyl ammonium acetate ionic liquids (ILs): hydroxyethylammonium acetate (HEAA), dihydroxyethylammonium acetate (DHEAA), or trihydroxyethylammonium acetate (THEAA) at 35 °C. The addition of ILs increased solubility significantly following the order: HEAA > DHEAA > THEAA. Solubility maximum of CaSO4·2H2O shifted toward a lower concentration of NaCl in solution with the addition of ILs. Mean ionic activity coefficients γ± of CaSO4·2H2O have been estimated as a function of solution ionic strength using the extended Debye–Huckel law with quadratic terms. The solubility product was calculated using a solubility equilibrium of CaSO4·2H2O. Density (ρ) and speed of sound (u) of (CaSO4·2H2O + NaCl + ILs + H2O) system have been recorded at 35 °C. Primary data on u and ρ were used to derive solution isentropic compressibility (κS). Polynomial equations have been used to fit the mea...

ChemInform Abstract: 2‐Hydroxyethylammonium Acetate as a Reusable and Cost‐Effective Ionic Liquid for the Efficient Synthesis of Bis(pyrazolyl)methanes (III) and 2‐Pyrazolyl‐1‐nitroalkanes (V).

AbstractTitle compounds (III) are prepared by one‐pot tandem Knoevenagel—Michael reaction of pyrazolone (I) with various aldehydes (II) in the presence of hydroxyethylammonium acetate as a task‐specific ionic liquid.

ChemInform Abstract: One‐Pot Synthesis of Thiazolo[3,2‐α]pyridine Derivatives Catalyzed by Ionic Liquids.

AbstractThree‐component reaction between methyl thioglycolate (I), aromatic aldehydes (III), and malononitrile or ethyl cyanoacetate (II) catalyzed by hydroxyethylammonium acetate provides a novel access towards title thiazolopyridines (IV).

Phospholipase A enzymes of Entamoeba histolytica: description and subcellular localization.

Cytolysis of target cells by Entamoeba histolytica is a rapid, contact-dependent event that appears to involve calcium and amebic phospholipase A enzymes. There are two phospholipase A enzymes of E. histolytica: one calcium independent and optimally active at an acid pH, and a second calcium dependent and most active at an alkaline pH. The amebic calcium-dependent enzyme was inhibited by pharmacological antagonists that have been shown to reduce cytolysis of target cells by intact amebae: phosphatidylcholine (10(-3) M), Rosenthal's inhibitor (dimethyl-dl-2,3-distearoylpropyl-2'-hydroxyethyl ammonium acetate; 10(-4) M), quinacrine (10(-4) M), and hydrocortisone (10(-4) M). Calcium-independent phospholipase A activity was inhibited by Rosenthal's inhibitor (10(-4) M) and quinacrine (10(-3) M). The calcium-dependent phospholipase A enzyme is highly associated with plasma membrane fractions; the calcium-independent enzyme is predominantly found in soluble fractions. These findings further suggest an association of calcium-dependent phospholipase A activity with cytolytic activity of E. histolytica.

Effect of antagonists of calcium and phospholipase A on the cytopathogenicity of Entamoeba histolytica.

The in vitro mechanisms by which Entamoeba histolytica trophozoites lyse target Chinese hamster ovary (CHO) cells were examined. Calcium chelators ethylenediaminetetraacetate and ethyleneglycol bis (beta-aminoethyl ether)-N,N'-tetraacetate (10 mM) inhibited amebic cytolysis of target CHO cells (P less than .01). A putative antagonist of intracellular calcium flux, 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8; greater than or equal to 250 microM), inhibited amebic adherence and cytolysis (P less than .001). Quinacrine, Rosenthal's inhibitor (dimethyl-dl-2,3-distearoyloxypropyl-2'-hydroxyethyl ammonium acetate), phosphatidylcholine, and hydrocortisone (greater than or equal to 10(-4) M), all pharmacological antagonists of eukaryotic phospholipase A enzymes, inhibited amebic killing of target CHO cells (P less than .001). At 37 C quinacrine and hydrocortisone reduced amebic adherence to CHO cells, whereas Rosenthal's inhibitor and phosphatidylcholine did not. Phosphatidylcholine and TMB-8 demonstrated a synergistic inhibitory effect on amebic killing of target CHO cells (P less than .001). These studies indicate that extracellular calcium ions, amebic intracellular calcium flux, and amebic phospholipase A activity are required for cytolysis of target cells by E. histolytica.

Rapid cell surface-related stimulation of alkaline phosphatase in HeLa cells by dimethyl DL-2,3-distearoylotypropyl-2'-hydroxyethylammonium acetate (Rosenthal's inhibitor).

Cultures of HeLa cells, strains S3G (HeLa65) and S3K (HeLa71) were grown in plastic dishes until firmly attached and were then treated with sonic dispersions of Rosenthal's phospholipase inhibitor. A rapid increase in alkaline phosphatase activity occurred following this treatment in the S3G strain (low inducible alkaline phosphatase) but not in the S3K strain (high constitutive alkaline phosphatase). The stimulatory effect was dependent on the presence of bovine serum in the medium. No stimulation of alkaline phosphatase was observed in a variety of soluble preparations of this enzyme.