Synthesis of 17beta-estradiol platinum(II) complexes: biological evaluation on breast cancer cell lines

The synthesis of a novel series of 17beta-estradiol-linked platinum(II) complexes is described. The new molecules are linked with an alkyl chain at position 16alpha of the steroid nucleus and bear a 16beta-hydroxymethyl side chain. They are made from estrone in five chemical steps with an overall yield exceeding 28%. The biological activity of these compounds was evaluated in vitro on estrogen dependent and independent (ER+ and ER-) human breast cancers. The derivatives incorporating a 2-(2'-aminoethyl)pyridine ligand displayed good activity against the cell lines particularly when the connecting arm is 10 carbon atoms long.