Synthesis, characterisation and potent cytotoxicity of unconventional platinum(iv) complexes with modified lipophilicity

Novel platinum(IV) complexes were synthesised to examine the facile modulation of the lipophilicity of the complex by incorporating axial ligands of increasing length, ranging from 2–6 carbons. RP-HPLC was used to establish the lipophilicity of each complex. The in vitro cytotoxicities of all complexes were determined against a panel of malignant cell lines and a non-cancerous cell line. While there was no clear correlation between lipophilicity and cytotoxicity, all complexes demonstrated nanomolar activity against all cell lines. The most potent complexes exhibited 850-fold greater activity than cisplatin against HT29 colon carcinoma with GI50 values of 13 nM.