Re-evaluation of Stoichiometric Dissociation Constants from Electrochemical Cell Data for Formic Acid at Temperatures from (0 to 60) °C and for Some Other Aliphatic Carboxylic Acids at (18 or 25) °C in Aqueous Potassium Chloride Solutions

2005 ◽  
Vol 50 (2) ◽  
pp. 497-507 ◽  
Author(s):  
Jaakko I. Partanen ◽  
Arthur K. Covington
Keyword(s):  
Formic Acid ◽  
Potassium Chloride ◽  
Carboxylic Acids ◽  
Electrochemical Cell ◽  
Dissociation Constants ◽  
Chloride Solutions ◽  
Aliphatic Carboxylic Acids ◽  
Cell Data

INHIBITION OF CATALASE BY CARBOXYLIC ACIDS RELATED TO DISSOCIATION AND ASSOCIATION OF THE APOPROTEIN

1962 ◽  
Vol 40 (1) ◽  
pp. 1327-1334 ◽  
Author(s):  
Michio Itoh ◽  
Yasuharu Nakamura ◽  
Kazuo Shibata
Keyword(s):  
Absorption Spectrum ◽  
Formic Acid ◽  
Carboxylic Acids ◽  
Free Acid ◽  
Second Step ◽  
Benzoic Acids ◽  
Reagent Concentration ◽  
Inhibitory Effects ◽  
Different Types ◽  
Aliphatic Carboxylic Acids

The inhibitory effects of aliphatic and aromatic carboxylic acids (formic, acetic, propionic, butyric, benzoic, and salicylic acids) on catalase at pH 7.0 were studied by measuring the catalatic activity as a function of reagent concentration, and the results were correlated with the data obtained simultaneously by spectroscopic and ultracentrifugal analyses. The inhibition by salicylic and benzoic acids proceeds in two steps. In the first step, the activity drops to a certain level, and the sedimentation peak of the native catalase is unaltered. The second step of inhibition is accompanied by the dissociation of the catalase molecule into subunits, and the absorption spectrum is changed greatly. The inhibition by the aliphatic carboxylic acids except formic acid proceeds also in two steps in which the second step of inhibition is accompanied by the association of the catalase molecules. The inhibition by formic acid obeys the mechanism of the combination between heme and the free acid rather than its anion. These different types of inhibitions at neutral pH are discussed in relation to the data obtained previously at acidic pH's.

INHIBITION OF CATALASE BY CARBOXYLIC ACIDS RELATED TO DISSOCIATION AND ASSOCIATION OF THE APOPROTEIN

1962 ◽  
Vol 40 (10) ◽  
pp. 1327-1334 ◽  
Author(s):  
Michio Itoh ◽  
Yasuharu Nakamura ◽  
Kazuo Shibata
Keyword(s):  
Absorption Spectrum ◽  
Formic Acid ◽  
Carboxylic Acids ◽  
Free Acid ◽  
Second Step ◽  
Benzoic Acids ◽  
Reagent Concentration ◽  
Inhibitory Effects ◽  
Different Types ◽  
Aliphatic Carboxylic Acids

The inhibitory effects of aliphatic and aromatic carboxylic acids (formic, acetic, propionic, butyric, benzoic, and salicylic acids) on catalase at pH 7.0 were studied by measuring the catalatic activity as a function of reagent concentration, and the results were correlated with the data obtained simultaneously by spectroscopic and ultracentrifugal analyses. The inhibition by salicylic and benzoic acids proceeds in two steps. In the first step, the activity drops to a certain level, and the sedimentation peak of the native catalase is unaltered. The second step of inhibition is accompanied by the dissociation of the catalase molecule into subunits, and the absorption spectrum is changed greatly. The inhibition by the aliphatic carboxylic acids except formic acid proceeds also in two steps in which the second step of inhibition is accompanied by the association of the catalase molecules. The inhibition by formic acid obeys the mechanism of the combination between heme and the free acid rather than its anion. These different types of inhibitions at neutral pH are discussed in relation to the data obtained previously at acidic pH's.

scholarly journals Determination of Stoichiometric Dissociation Constants for Propionic Acid in Aqueous Sodium or Potassium Chloride Solutions at 298.15 K.

1999 ◽  
Vol 53 ◽  
pp. 547-556 ◽  
Author(s):  
Jaakko I. Partanen ◽  
Pekka M. Juusola ◽  
Pentti O. Minkkinen ◽  
Juliusz A. Wolny ◽  
Terje Thomassen ◽  
...  
Keyword(s):  
Potassium Chloride ◽  
Propionic Acid ◽  
Dissociation Constants ◽  
Chloride Solutions ◽  
Aqueous Sodium

Determination of Stoichiometric Dissociation Constants of Glycolic Acid in Dilute Aqueous Sodium or Potassium Chloride Solutions at 298.15 K

2001 ◽  
Vol 215 (4) ◽  
Author(s):  
Jaakko I. Partanen ◽  
P.M. Juusola ◽  
P.O. Minkkinen
Keyword(s):  
Potassium Chloride ◽  
Dissociation Constant ◽  
Glycolic Acid ◽  
Dissociation Constants ◽  
Chloride Solutions ◽  
Aqueous Sodium

Equations were determined for the calculation of the stoichiometric (molality scale) dissociation constant, K

Formation of Aliphatic Carboxylic Acids during Soda-AQ Pulping of Kenaf Bark

Holzforschung ◽  
2002 ◽  
Vol 56 (4) ◽  
pp. 388-394 ◽  
Author(s):  
Z. Feng ◽  
R. Alén ◽  
K. Niemelä
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Carboxylic Acids ◽  
Dicarboxylic Acids ◽  
Hydroxy Acids ◽  
Hydroxy Carboxylic Acids ◽  
Aliphatic Carboxylic Acids ◽  
Cooking Conditions ◽  
Acetic Acids

Summary The formation of aliphatic carboxylic acids during soda-AQ pulping of kenaf bark was studied. In addition to formic and acetic acids, a variety of hydroxy monocarboxylic and dicarboxylic acids were monitored. The results showed that the formation of hydroxy acids and formic acid significantly depend, in contrast to acetic acid, on the cooking conditions employed. Detailed gas chromatographic studies revealed that the most abundant hydroxy carboxylic acids were glucoisosaccharinic, lactic, glycolic, 3-deoxypentonic, 2-hydroxybutanoic, xyloisosaccharinic, 3,4-dideoxypentonic, 2-hydroxyglutaric, and glucoisosaccharinaric acids. The total amount of aliphatic carboxylic acids corresponded to 12–16% of o.d. kenaf bark.

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