ABSTRACT
In the absence of precise information regarding the biological mechanisms that contribute to the production of the biological activity, and in the absence of satisfactory information regarding the state of the metal ions in biological environments (this could be either the free ion state or, most probably, the bonded form in a chemical compound), a suitable quantitative structure-activity relationship (QSAR) approach would be to choose descriptors that represent the long path that the metal ions have to travel up to the biological target (Schwietert and McCue 1999). The choice of descriptors must consider all the physical-chemical processes that happen to the metal ion or metal compound up to the last event, which is the interaction with the biological receptor. Correspondingly, a good correlation of metal biological activity with descriptors depends on a better understanding of the physicochemical or biological mechanisms in which metal ions participate in biological environments.
