COMPLEX-COMPOUNDS OF PLATINUM(II) AND PLATINUM(IV) WITH AMINO-ACIDS, PEPTIDES AND THEIR DERIVATIVES

This article reviews all the known Pt(II) and Pt(IV) complexes with amino acids, peptides and their analogues referred in the literature. It gives details on the work done after 1975 since excellent reviews on the subject before that date have been published previously. The compounds described have been classified, in the first place, according to the metal ion oxidation state and in the second according to the binding site(s) of the ligand(s). Section 1 refers briefly to the reasons for studying platinum complexes with amino acids and similar molecules and gives the orientation of the research on the topic in recent years. In Sect. 2, the known Pt(II) complexes are reviewed in four sub-sections. The first describes the complexes with the metal ion binding to the terminal amino group or/and to a ring nitrogen of a side chain of the amino acid. This coordination mode is easily achieved and results in various products when the ligand contains more than one nitrogen donor atom. The second sub-section describes the complexes with the metal simultaneously binding to a nitrogen and one or more oxygen donor atoms of the ligand. A large number of stable chelates are thus formed. In contrast, binding of an amino acid or analogue through only an oxygen donor atom is not easily achieved. The third sub-section describes the complexes formed with sulphur-containing ligands. In such complexes, coordination of sulphur, which is the primary binding site, may result in bridged or oligomeric complexes. The fourth sub-section refers to the organometallic Pt(II) complexes which contain an amino acid or analogue coordinated through an amino terminal group or chelated through nitrogen and oxygen donor atoms. In Sect. 3, the known Pt(IV) complexes are reviewed in four sub-sections corresponding to those in Sed. 2. The same amino acid coordination modes are also found here. Finally, Sect. 4 summarizes the conclusions drawn from the previous three sections and emphasizes their most important features.