There is a growing interest in the use of chelate therapy in medicinal chemistry. An example is the treatment of problems caused by the presence of metals in toxic proportions in plants/animals. Thus, excess of copper and iron are removed by chelating ligands D-penicillarnine and desferrioxime. B via the formation of coordination compounds. EDTA is used in the treatment of lead poisioning. Some coordination compounds of platinum effectively inhibit the growth of tumours. Examples are cis-platin and related compounds. Coordination compounds are of great importance in biological systems. The pigment responsible for photosynthesis, chlorophyll, is a coordination compound of magnesium. Haemoglobin, the red pigment of blood which acts as oxygen carrier is a coordination compound of iron. Vitamin B_(12), cyanocobalam.ine, the antipernicious anaemia factor is a coordination compound of cobalt. Name the coordination compound that can be used to cure tumours.