Reversed-phase thin-layer chromatography with different stationary phases in studies of quantitative...

Reversed-phase thin-layer chromatography with RP-8, RP-18, and RP-18W stationary phases was used in quantitative structure-activity relationship (QSAR) studies of new antimycotic compounds. The retention behavior of 10 dihydroxythiobenzanilides was examined for acquisition of log k' data. With water-acetone mixtures as the mobile phases, the concentration range for which the correlation between log k' and acetone concentration is linear was established for each stationary phase and used to determine hydrophobicity parameters log k'w by linear extrapolation. The effect of substituents on retention constants was quantitated by using the group contribution parameters tau W. On the basis of QSAR equations obtained from these studies, log k'w data can be used to predict antifungal activities of dihydroxythiobenzanilides with satisfactory accuracy.