Study of hydrophobic properties of biologically active open analogues of flavonoids

Hydrophobicity can either be determined experimentally or predicted by means of commercially available programs. In the studies concerning biological activities of pyrazine analogues of chalcones, 3-(2-hydroxyphenyl)-1-(pyrazin-2-yl)prop-2-en-1-ones were more potent than the corresponding 3-(4-hydroxyphenyl)-1-(pyrazin-2-yl)prop-2-en-1-ones. As the difference in lipophilicity may be a factor responsible for the difference in the potency, RM values of the compounds were determined by RP-TLC and compared with log P values calculated by various commercially available programs. Important discrepancies were found between experimental and computational lipophilicity data. Therefore, we have tried to find a reliable method for calculating RM values from in silico derived molecular parameters. The RM values obtained with the chromatographic system consisting of Silufol UV 254 plates impregnated with silicon oil as the stationary phase and acetone–citrate buffer (pH = 3) 50:50 (v/v) as the mobile phase correlated well with van der Waals volumes (VW) and hydration energies (ΔGH2O) derived of molecular models calculated on RHF/AM1 level.

Figure optionsDownload high-quality image (169 K)Download as PowerPoint slideHighlights
► Discrepancies were found between experimental RM values and computational log P.
► We tried to find a method for calculating RM values from molecular parameters.
► The RM values correlated well with van der Waals volumes and hydration energies.