Quantitative Relationships Between Structure, Aggregation Properties and Antimicrobial Activity of Quaternary Ammonium Bolaamphiphiles

Abstract

QSAR analysis employing Kubinyi's bilinear model was applied to examine the relationship between the structure (characterized by the lengths of the terminal hydrocarbon chain, m, and of the hydrocarbon spacer chain, y), lipophilicity (characterized by the chromatographic parameter Rm and aggregation properties expressed through the critical micellar concentration cK), and antimicrobial activity (characterized by the minimum inhibition concentration, MIC) of quaternary ammonium bolaamphiphiles. The log cK = f(m) dependence was found to be linear whereas the log (1/MIC) = f(m), log (1/MIC) = f(y), log (1/MIC) = f (log cK) and log (1/MIC) = f(Rm) dependences were nonlinear. The effect of the hydrophobic terminal chains (m) and of the hydrophobic spacer chain (y) on the aggregation properties and on the biological activity of the substances was studied.