S-aryl (tetramethyl) isothiouronium salts as possible antimicrobial agents, IV.

The 1-octanol/water partition coefficients of a series of antimicrobial S-aryl(tetramethyl)isothiouronium salts, were determined. The concentration of the solute in the two phases was measured by means of HPLC. The values of the hydrophobic parameters thus obtained were correlated to the corresponding capacity factors (log Kw) and compared with those expected on the basis of additive-constitutive principles. The deviations were interpreted quantitatively on the basis of electronic interactions of the substituents in the benzene ring. Equations correlating structural features and antimicrobial activity of some studied compounds by means of molecular parameters were formulated.