CISPLATIN - THE LAST 5 YEARS

This review looks at developments in the chemistry of cisplatin, cis-[Pt(NH3)2Cl2], and its relatives, such as cis-[Pt(NH3)2(OH2)2]2+. Particular attention is paid to substitution reactions involving the cis-Pt(II)(NH3)2 centre. This moiety will form coordination compounds with phosphates, thiolates, thioethers, amines and carboxylates, interesting examples being provided by aminoacids including those containing thiol groups. Though usually inert, the cis-Pt(II)(NH3)2 unit can be destroyed by cyanide ions and by thiourea. The kinetics of reactions with mononucleosides and mononucleotides provide models for the attack of cisplatin on DNA. In nucleotide chains the cis-Pt(II)(NH3)2 moiety has a particular affinity for GG units forming activated Pt(GG) chelates, although species such as activated Pt(GTG) can be formed. There is evidence that the attack of cis-[Pt(NH3)2Cl2] and cis-[Pt(NH3)2(OH2)2]2+ on DNA is a four step process.