Synthesis, Characterization, and Biological Properties of Steroidal Ruthenium(II) and Iridium(111) Complexes Based on the Androst-16-en-3-ol Framework

A range of novel cyclometalated ruthenium(II) and iridium(III) complexes with a steroidal backbone based on androsterone were synthesized and characterized by NMR spectroscopy and X-ray crystallography. Their cytotoxic properties in RT112 and RT112 cP (cisplatin-resistant) cell lines as well as in MCF7 and somatic fibroblasts were compared with those of the corresponding nonsteroidal complexes and the noncyclometalated pyridyl complexes as well as with cisplatin as reference. All steroidal complexes were more active in RT112 cP cells than cisplatin, whereby the cyclometalated pyridinylphenyl complexes based on 5c showed high cytotoxicity while maintaining low resistant factors of 0.33 and 0.50.