RP TLC determination of the lipophilicity of new 10-substituted 2,7-diazaphenothiazines

Experimental (R-M0 and log PTLC) and calculated (log(Pcalcd)) lipophilicity parameters of eleven new bioactive 10-substituted 2,7-diazaphenothiazines 2-12 were determined by reversed-phase thin-layer chromatography on RP-18 silica plates, with acetone-aqueous TRIS (tris(hydroxymethyl)aminomethane) buffer as the mobile phase, and obtained by the calculation program miLogP. The parameter R-M0 was converted into parameter log PTLC by use of a calibration curve obtained for five standards. The lipophilicity parameters were intercorrelated and discussed in the terms of structure-lipophilicity relationships. The parameter R-M0 and specific hydrophobic surface area b were significantly intercorrelated showing three congeneric subclasses of 2,7-diazaphenothiazines 2-12. The 2,7-diazaphenothiazine system turned out to be less lipophilic than the classical phenothiazine one.