New method for the determination of permeation coefficients of functional chemical groups using membrane model vesicles

1989 ◽  
Vol 67 (10) ◽  
pp. 1606-1608
Author(s):  
Jean-Louis Kraus ◽  
Sophie Micheau ◽  
Philippe Pernice ◽  
Madeleine Castaing
Keyword(s):  
Partition Coefficients ◽  
Water System ◽  
Quantitative Structure Activity Relationship ◽  
Membrane Model ◽  
Excellent Correlation ◽  
Hydrophobic Properties ◽  
Structure Activity ◽  
Substituent Constants ◽  
Chemical Groups

New substituent constants πp, derived from permeation coefficients, of membrane model vesicles have been evaluated for fifteen functional groups. The excellent correlation found between the new substituent constants and the values derived from partition coefficients in octanol–water system leads one to consider this new parameter and the technique used for its evaluation as new promising tools for quantitative structure–activity relationship studies and for hydrophobic properties measurement. Keywords: permeation coefficients, model membrane, dihexadecyl-phosphate vesicles.

scholarly journals A Benchmark Dataset Comprising Partition and Distribution Coefficients of Linear Peptides

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Matthew N. Davies ◽  
Darren R. Flower
Keyword(s):  
Organic Solvent ◽  
Small Molecules ◽  
Partition Coefficients ◽  
Dominant Role ◽  
Quantitative Structure Activity Relationship ◽  
Chemical Substance ◽  
Distribution Coefficients ◽  
Quantitative Structure ◽  
Qsar Analysis ◽  
Structure Activity

Peptides have a dominant role in biology; yet the study of their physical properties is at best sporadic. Peptide quantitative structure-activity relationship (QSAR) lags far behind the QSAR analysis of drug-like organic small molecules. Traditionally, QSAR has focussed on experimentally determined partition coefficients as the main descriptor of hydrophobicity. A partition coefficient () is the ratio between the concentrations of an uncharged chemical substance in two immiscible phases: most typically water and an organic solvent, usually 1-octanol. A distribution coefficient () is the equivalent ratio for charged molecules. We report here a compilation of partition and distribution coefficients for linear peptides compiled from literature reports, suitable for the development and benchmarking of peptide and prediction algorithms.

QSARs on Bactericidal Activity of 3-carboxy-4-quinolones

2008 ◽  
Vol 59 (2) ◽  
pp. 185-194 ◽  
Author(s):  
Laszlo Tarko ◽  
Lucia Pintilie ◽  
Catalina Negut ◽  
Corneliu Oniscu ◽  
Miron Teodor Caproiu
Keyword(s):  
Escherichia Coli ◽  
Bactericidal Activity ◽  
Molecular Shape ◽  
Quantitative Structure Activity Relationship ◽  
Quantitative Structure ◽  
Specific Criterion ◽  
Structure Activity ◽  
Dependent Property ◽  
Chemical Groups ◽  
Derivatives Of

This paper presents results of three QSAR (Quantitative Structure Activity Relationship) studies realized with the PRECLAV computer program. The database we used contains initially 100 derivatives of 3-carboxy-4-quinolone. The dependent property is bactericidal activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. A specific criterion identifies the outlier molecules in the calibration set. Two molecules are identified as �possible outliers for lead hopping�. After the elimination of outliers, we obtained: N = 77 / 86 / 84, s = 0.2904 / 0.3583 / 0.2993, r2 = 0.8850 / 0.7943 / 0.8645, F = 91.1 / 37.6 / 82.9 and r2CV = 0.8415 / 0.7337 / 0.8415. The bactericidal activity against the three studied bacteria was favored by the presence of saturated C substituted (hetero)cycles, by the presence of certain groups (-F, unconjugated -NH/-NH2) and by a non-balanced molecular shape. The bactericidal activity was disfavored by the presence of certain chemical groups (-NO2, -C6H4, -CO-) and of the triazole cycle. The lipophilic/hydrophilic feature of quinolones has little impact upon bactericidal activity.

Characterization of the hydrophobic properties of amino acids on the basis of their partition and distribution coefficients in the 1-octanol-water system

1991 ◽  
Vol 56 (10) ◽  
pp. 2030-2041 ◽  
Author(s):  
Josef Chmelík ◽  
Jiří Hudeček ◽  
Karol Putyera ◽  
Jiří Makovička ◽  
Vítěz Kalous ◽  
...  
Keyword(s):  
Amino Acids ◽  
Water System ◽  
Distribution Coefficients ◽  
Published Data ◽  
Hydrophobic Properties ◽  
Charged Amino Acids ◽  
Hydrophobic Amino Acids ◽  
Partition Process

The hydrophobic properties of amino acid side chains were characterized on the basis of the partition process in the 1-octanol-water system. The partition coefficients were calculated from the published data and the distribution coefficients were determined experimentally on the basis of a double partition process utilizing the fact that the amino acids pass almost completely into the aqueous phase in the partition process. When the volumes of water and 1-octanol are suitably selected, this fact permits avoidance of the difficulties associated with the determination of amino acids in 1-octanol, where their solubilities are very low. Our scale is the only complete experimental scale based on the partition process of amino acids in the 1-octanol-water system. It follows from comparison of the calculated and the experimental data with the values published for the distribution coefficients of N-acetyl amides of amino acids that the best agreement was achieved for hydrophobic amino acids, while greater differences were observed for hydrophilic amino acids. These differences, expressed as the logarithm of the distribution coefficients, correspond to an average of 0.08 for nonpolar amino acids and 0.30 for acidic and basic amino acids: expressed as relative deviations, these values correspond to 2-10% for nonpolar amino acids, and 5-30% for charged amino acids.

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