6 Cisplatin

The Pt(II) complex cisplatin is used as an anticancer drug. Pt 2+ Cl – Cl – H3N H3N Pt 2+ NH3 ClClH N3 cisplatin transplatin The cisplatin version only works as two chloride ions are displaced and the molecule joins on to the DNA. In doing this it stops the replication of cancerous cells. Cisplatin Cisplatin can also prevent the replication of healthy cells by bonding on to healthy DNA which may lead to unwanted side effects like hair loss. Society needs to assess the balance between the benefits and the adverse effects of drugs, such as the anticancer drug cisplatin. Cisplatin prevents DNA replication in cancer cells by a ligand replacement reaction with DNA in which a dative covalent bond is formed between platinum and a nitrogen atom on guanine Pt NH3 NH3 N NH NH N NH2 O The N and O atoms marked in red can’t bond to cis-platin as they are involved in the bonding within the DNA