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 antimicrob ial, antimycotic, and tuberculostatic agents. In addition, they are relativ ely weakly toxic to higher organisms. A large set of new (N-phenyl-)-2,4-dihydroxybenzenecarbothioamide derivativ es 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 parame ters correspond to hydrophobicity of the solute. Obtained chromatographic p arameters exhibited moderate correlation with calculated log P parameter. Linear dependence of bacteriostatic or fungostatic activity on lipophilicit y was observed. The degree of correlation of different parameters was compa red. The lipophilicity of analysed tioamides was the most important factor responsible for fungostatic and bacteriostatic activity. In comparison to m ethanol eluent system, chromatographic parameters obtained in acetonitrile system were better correlated with bioactivity. Conversely with the calcula ted log P values, the experimentally derived parameters exhibited significa nt higher correlation to fungostatic activity determined on dermatophytes. While in case of other tested microorganisms log P was comparably or someti mes slightly better correlated.