Synthesis of 17β-estradiol-platinum(II) hybrid molecules showing cytotoxic activity on breast cancer cell lines

The synthesis of a series of 17β-estradiol-platinum(II) hybrid molecules is reported. The hybrids are made of a PEG linking chain of various length and a 2-(2′-aminoethyl)pyridine ligand. They are prepared from estrone in five chemical steps with an overall yield of 22%. The length of the PEG chain does not influence the solubility of the compounds as it remains relatively constant throughout the series. MTT assays showed that the derivative with the longest PEG chain showed the best activity against breast cancer cell lines (MCF-7 and MDA-MB-231). Molecular modeling study rationalized the results.