[Stability of ferricinium cations and their cytostatic effect].

The relative stabilities of different ferricinium cations were studied in buffer or serum-containing solution and in vivo and compared with their cytostatic effects in cultures of Yoshida ascites tumor cells. Although the ferricinium cation itself was the most unstable cation compared with the dimethyl-ferricinium cation and the deuterated ferricinium derivatives it showed the highest cytostatic effect.