Correlation of fungostatic activity with log P and sigma parameters in the group of thiobenzanilides.

2,4-Dihydroxythiobenzanilide and its analogues were recently found to show strong biological activity. Earlier works exhibited that their biological activity depends strongly on their lipophilicity determined by means of RP-HPLC. Among others, fungostatic activity against tested yeast and mould strains appeared to be comparatively poorer modelled by chromatographic lipophilicity parameters. Very high correlation (r approximately 0.85-0.9) with these activities was obtained by means of multiparameter regression analysis where calculated log P and Hammet sigma values were involved as the independent variables. Analysed data show that activity against yeast and mould fungi is a superposition of two basic properties of thiobenzanilides: their lipophilicity and electronic properties.