Studies on Ruthenium—Amine Complexes

Detailed studies on reactions of the [Ru(NH3)5(H20)] cation with nucleic acid and constituent bases have broadened the range of reactions that can take place. The results may be summarized as follows  

A number of chemical and biochemical effects of the binding of Ru to DNA have been observed and these include [44]  

Work with bases and nucleosides complements that of the platinum systems and in addition has broadened the range of reactions observed. The types of reactions have been discussed in more detail in Chapter 4 and are briefly summarized  

The acid—base properties of the purines, and in particular the of endocyclic nitrogens, are affected by metallation. 

The role of Cu as an essential trace element has focused attention on possible roles for copper chelation of biologically active ligands, with subsequent interference of normal transport and distribution, as well as the role of the metal in redox reactions due to the accessible oxidation states of (I) and (II). Similarly, the physiological response of copper levels in disease conditions [50] and the overall role of trace metals in health and disease [51, 52] are relevant and of considerable importance. The increase in serum copper content in infections, arthritic diseases, and certain neoplasms is well documented and, in fact, the subsequent decrease in level upon treatment has been used successfully as an indicator of cancer remission [50]. Copper complexes may be effective in therapy due in part to their ability to mimic this physiological response of elevated copper [53] and, clearly, the interplay of introduced copper with pre-existent bound copper and effects on copper—protein mediated processes will affect the ultimate biological fate of the complex. Likewise, while the excess accumulation of free Cu, and indeed Fe and Zn, caused by malfunction or absence of normal metabolic pathways is extremely damaging to the body, the controlled release of such metals may be beneficially cytotoxic. The widespread pharmacological effects of copper complexes have been briefly reviewed [54]. 

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