Lipophilicity Evaluation of Some N1- Arylidene-Thiosemicarbazones and 1,3,4-Thiadiazolines with Antimicrobial Activity

The lipophilic character of 20 previously reported compounds-derivatives of N-1-arylidene-thiose-micarbazone (series A) and their corresponding 1,3,4-thiadiazolines (series B)-has been determined by reversed-phase thin-layer chromatography, using i-propanol-water mixtures as eluents. Principal component analysis (PCA) allowed an objective estimation of the retention behavior of the tested compounds and also afforded to obtain a 2D scatterplot, described by the first two principal components, which had the effect of separating the compounds from each other most effectively. With the use of clustering methods (K-means clustering) based on PCA data, the studied compounds were grouped into two congeneric classes. When comparing the obtained lipophilicity parameters' values with the antibacterial properties of the tested compounds, we noticed that the lipophilic character had no significant influence on their growth inhibitory activity.