Assessing the pharmacological potential of selected xanthene derivatives

A convenient and efficient approach toward the synthesis of seven aromatically substituted xanthendiones (1?7) and one structurally-related xanthenone (8) through condensation of dimedone and the appropriate aromatic aldehyde is reported. Further, their chemical structure was confirmed by melting points, elemental analysis, FT-IR, 1H, 13C NMR and UV-Vis spectroscopic methods. The relationship between the chemical structure and pharmacological activity was determined empirically using appropriate software packages and in vitro using the ABTS (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) method. The results of in silico prediction suggested that all investigated compounds possess good oral bioavailability. The results of the ABTS assay indicate that five compounds possess the ability to scavenge the ABTS?+ radical cation. Based on the comparison of the IC50 values, the activity of the compounds was found to be as follows: 6 > 1 > 7 > 2 > 8. The effects of solvent dipolarity/polarizability and solute solvent-hydrogen-bonding interactions on the shifts of the absorption maxima were rationalized by means of the linear solvation energy relationship concepts proposed by Kamlet-Taft and Catal?n.