Collect. Czech. Chem. Commun. 1987, 52, 2819-2825

Acidobasicity, reactivity, lipophilicity, and ability of phenylhydrazonopropanedinitriles to disturb the membrane potential

Ernest Šturdíka, Edita Ďurčováa, Vladimír Mikešb, Vladimír Dadákb, Štefan Baláža, Pavol Suloc and Marián Antalíkd

a Department of Biochemical Technology, Faculty of Chemical Technology, Slovak Institute of Technology, 812 37 Bratislava
b Department of Biochemistry, Faculty of natural Sciences, J. E. Purkyně University, 611 37 Brno
c Section of Enzyme Technology, Institute of Biotechnology, Slovak Institute of Technology, 812 37 Bratislava
d Biophysical Laboratory, Institute of Experimental Physics, Slovak Academy of Sciences, 040 11 Košice


The ability to disturb the membrane potential of rat liver mitochondria or Paracoccus denitrificans bacteria was quantitatively determined with 21 o-, m-, and p-substituted phenylhydrazonopropanedinitriles. Dependence of this ability on partition coefficients, dissociation constants and nucleophilic reactivity of these derivatives was characterized by equations employed in quantitative structure-activity relationship (QSAR); as found, decisive for investigating the disturbance effect is the lipophilicity of phenylhydrazonopropanedinitriles which determines their ability to pass through biomembranes. Close values of optimal lipophilicities (log P = 3.98 or 3.81) of models under examination indicate the very like lipo-hydrophilic character of both membranes. Of further parameters considered, the more significant is the acidobasicity, determining the ability of these substances to transfer protons through the interface, thereby disturbing the pH-gradient as a substantial component of the membrane potential.