“…Pol'shakov et al found that the guanine residues may be the main binding sites for prospidine to DNA, in contrast to spirobromine, which does not bind to them [ 55 ]. Moreover, Geodakyan and Chernov suggested that the effect of prospidine on intracellular processes in tumor cells may be mediated by the effect of the drug on the permeability of their plasma membrane [ 56 , 57 ]. But these studies were carried out many years ago and have not yet been confirmed with modern methods.…”