[DNA liquid crystals as a possible system of testing the interactions between DNA and biologically active compounds of platinum (II) and various antibiotics].

DNA liquid crystals forming in water-salt solutions containing polyethylene glycol were used as a system for testing consequences of reactions of antitumor compounds belonging to two different groups with molecules of nucleic acids. It was found that with due account of the level of DNA molecule filling with daunorubicin it was possible to form two cholester phases characterized by the textures of "finger prints" and CD spectra with intensive bands of unlike signs, as well as the nematic phase characterized by the texture of the "black twisted fiber" system and the absence of the CD spectrum intensive band. Modification of the DNA molecules resulting from the reaction with cysdichlorodiamine platinum (II) led to formation of a new liquid crystalline phase with properties differing from those of the liquid crystalline phases of the cholester or nematic type.