Effects of histidin-2-ylidene vs. imidazol-2-ylidene ligands on the anticancer and antivascular activity of complexes of ruthenium, iridium, platinum, and gold

The 1,3-dimethyl-N-boc-O-methylhistidin-2-ylidene ligand augments the cytotoxicity of metal fragments by increasing the cellular accumulation and by initiating distortion and unwinding of DNA. We identified a new platinum(II) complex which was cytotoxic against multidrug- and cisplatin-resistant cancer cells. In xenografted mice it was as active as cisplatin, yet better tolerated.48