DISCO—a general computer program for the computation of acid dissociation constants of polyprotic molecules in water and biological fluids, from nuclear magnetic resonance data: application to polyamines

2003 ◽  
Vol 319 (2) ◽  
pp. 179-194 ◽  
Author(s):  
Fabiano Reniero ◽  
Claude Guillou ◽  
Chiara Frassineti ◽  
Stefano Ghelli
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Dissociation Constants ◽  
Biological Fluids ◽  
Acid Dissociation ◽  
Acid Dissociation Constants ◽  
Magnetic Resonance Data ◽  
Data Application ◽  
Resonance Data ◽  
General Computer Program ◽  
General Computer

Theoretical calculations of acid-dissociation constants of proteins

1998 ◽  
Vol 76 (2-3) ◽  
pp. 198-209 ◽  
Author(s):  
André H Juffer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Dissociation Constants ◽  
Theoretical Calculations ◽  
Acid Dissociation ◽  
Continuum Electrostatics ◽  
Acid Dissociation Constants ◽  
Computational Procedures ◽  
Nuclear Magnetic

The purpose of this review is to introduce several computational procedures for the determination of acid-dissociation constants (pKa) of titratable groups in proteins. Several concepts, such as continuum electrostatics and the exact meaning of intrinsic and apparent pKas, will be explained in some detail. Each of the methods will be judged on its merits, and some comparisons between the methods will be presented. While the emphasis of this review will be on theoretical formulations, the experimental determination by means of nuclear magnetic resonance will be briefly explained. The determination of individual pKa values by nuclear magnetic resonance in combination with computationally determined pKas can provide unique information about the pH-dependent properties of proteins and their complexes with peptides, DNA, and ligands.Key words: acid-dissociation constants, NMR, continuum electrostatics, dielectric constant of proteins, Monte Carlo, molecular dynamics.

Preparation and nuclear magnetic resonance studies of diaryloxytriphenylphosphoranes. Correlation of substituent effects with 31P N.M.R. chemical shifts

1984 ◽  
Vol 37 (12) ◽  
pp. 2447 ◽  
Author(s):  
Mv Itzstein ◽  
ID Jenkins
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Dissociation Constants ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Acid Dissociation ◽  
Linear Free Energy Relationship ◽  
Acid Dissociation Constants ◽  
Magnetic Resonance Studies ◽  
Linear Free Energy ◽  
Electron Donating Groups

Triphenylphosphine and diisopropyl azodicarboxylate react with phenols in tetrahydrofuran or chloroform at 0° to give diaryloxytriphenylphosphoranes. A linear free-energy relationship has been found between the 31P n.m.r. chemical shifts of many of these phosphoranes and the acid dissociation constants of the corresponding phenols. In general, electron-withdrawing groups on the phenol result in downfield 31P n.m.r. chemical shifts, while electron donating groups result in up-field shifts.

Methods to Determine Phytopharmaceuticals in Tobacco and Tobacco Products. 4th Report: A Procedure to Determine Vamidothion and its Metabolites/Methoden zur Bestimmung von Phytopharmaka in Tabak und Tabakerzeugnissen: IV. Mitteilung: Ein Bestimmungsverfahren fuer Vamidothion und seine Metaboliten

1977 ◽  
Vol 9 (2) ◽  
Author(s):  
A.N. Sagredos ◽  
R. Moser
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Acetic Acid ◽  
Magnetic Resonance ◽  
Aluminium Oxide ◽  
Nuclear Magnetic Resonance Data ◽  
Gas Chromatograph ◽  
Tobacco Products ◽  
Magnetic Resonance Data ◽  
Resonance Data

AbstractBased on previous work (7) a method to simultaneously determine vamidothion [I], vamidothion-sulfoxide [II] and vamidothion sulfone [III] in tobacco has been developed. The compounds are extracted with water/acetone/acetic acid from the tobacco, cleansed over an aluminium oxide column and then determined on the gas chromatograph with the specific sulphur detector. Rates of recovery are 70 % - 92 %, the determination level is 0.1 ppm. Mass spectrometry and nuclear magnetic resonance data of vamidothion [I], vamidothion-sulfoxide [ II ] and vamidothion-sulfone [III] are given.

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