The development of Pt-complexes of the type 1,2-bis(4-hydroxyphenyl)ethylenediamines as ligands for estrogen receptors of receptor-pos. and -neg. mammary cancer cells is discussed. The degree of receptor affinity of the ligand was dependent on its configuration, i.e. the R,R- and the S,S-conformations, in contrast to the R,S conformation, were more effective for inhibition of estradiol-receptor interactions. An ethylenediamine structure was essential for antitumor activity of these compds. Exptl. results with various tumor systems demonstrated that R,R-dichloro-1,2-bis(4-hydroxyphenyl)ethylenediamine-Pt(II)-complex (I) [91326-63-5] was the most active compd. I as an antitumor drug seems promising since it has only slight nephrotoxic effects and no myelotoxic effects
