Effect of selected dimethylaminochalcones on some mitochondrial activities.

Chalcones and their synthetic cyclic analogues have been shown to possess a full scale of biological activities in a variety of experimental systems. They were assessed to be mostly effective in defense against free radicals in the organism, but several compounds exhibited cytotoxic pro-oxidant activities. The respiratory response and antioxidant status in mitochondria were investigated upon addition of 4'-dimethylaminochalcone (1a) and its cyclic analogues, (E)-2-(4'-((CH3)2 N)-benzylidene)-1-indanone (1b), -1-tetralone (1c), and -1-benzosuberone (1d). Selected structures were able to change the respiratory response of mitochondria and showed an ability to modify mitochondrial metabolic and redox efficiency, though they did not indicate redox reactivity towards glutathione in adduct-free incubations. The results of the study indicate that -chalcone and -tetralone derivatives cause suppression of reactive oxygen species affecting mitochondrial respiration by mild uncoupling. In addition, (E)-2-(4'-((CH3)2 N)-indanone (1b), and to a greater extent, -benzosuberone (1d), showed pro-oxidant effects, which partially explain their cytotoxicity.

Some fluorescence properties of dimethylaminochalcone and its novel cyclic analogues.

This paper demonstrates the basic character (polarity, solubility, colour, absorption and fluorescence quantum yield) of synthetic dimethylaminochalcone (1) and its cyclic analogues measured in toluene, chloroform, dimethylsulfoxide and ethanol, which have been studied by absorption and fluorescence spectroscopy. The biologically active dye 4'-dimethylaminochalcone (1b) and its less flexible analogues 4-dimethylaminoindanone (2b), -tetralone (3b), and -benzosuberone (4b) are lipophilic molecules that displayed the best solubility in toluene and chloroform. The highest fluorescence and quantum yields of compounds 1 and 2 have been obtained in DMSO and chloroform. Quenching effect of fluorescence compounds (1-4) has been studied in the mixture of the most polar organic solvents DMSO and water. In the presence of water, fluorescence of compound 1 has been quenched the best from all studied chalcones and emission maxima of molecules 1-4 have been shifted to the longer wavelengths. Quenching effect of fluorescence by water was in order 1 > 2 > 3 > 4.