Comparison of effect of selected synthetic chalcone analogues on mitochondrial outer membrane determined by fluorescence spectroscopy.

Effect on mitochondrial outer membrane of six selected synthetic cyclic chalcone analogues, E-2-arylmethylene-1-tetralones (2) and E-2-arylmethylene-1-benzosuberones (3), were investigated by fluorescence spectroscopy. The selected compounds represent derivatives with different degree of cytotoxicity against murine and human cancer lines. Excitation and emission fluorescence spectra of the cyclic chalcone analogues 2 and 3 were recorded in respiration medium containing 1 mM succinate. It was found that the ring size as well as the nature and location of the aromatic substituents have significant effect on fluorescence of the compounds. Interaction of subtoxic concentration of compounds 2 and 3 with the outer mitochondrial membrane was investigated by recording their fluorescence polarization in the presence of rat liver mitochondria. The most cytotoxic E-2-(4'-methoxybenzylidene)-1-benzosuberone (3b) was found to display a continuous increase of fluorescence polarization signal in the presence of mitochondria--a different pattern of interaction with the mitochondrial outer membrane from that observed for rest of the investigated compounds.