Use of reversed-phase high-performance liquid chromatography in QSAR analysis of 2,4-dihydroxythiobenzanilide analogues

Thiobenzanilides are found to show strong biological activity as antimicrobial, antimycotic, and tuberculostatic agents. In addition, they are relatively weakly toxic to higher organisms. A large set of new (N-phenyl-)-2,4-dihydroxybenzenecarbothioamide derivatives was obtained. Preliminary studies showed high microbiological action of some of them. In the process of chromatographic analysis, several different chromatographic parameters were obtained. In case of RP-HPLC, these parameters correspond to hydrophobicity of the solute. Obtained chromatographic parameters exhibited moderate correlation with calculated log P parameter. Linear dependence of bacteriostatic or fungostatic activity on lipophilicity was observed. The degree of correlation of different parameters was compared. The lipophilicity of analysed tioamides was the most important factor responsible for fungostatic and bacteriostatic activity. In comparison to methanol eluent system, chromatographic parameters obtained in acetonitrile system were better correlated with bioactivity. Conversely with the calculated log P values, the experimentally derived parameters exhibited significant higher correlation to fungostatic activity determined on dermatophytes. While in case of other tested microorganisms log P was comparably or sometimes slightly better correlated.