Studies of rhodium (II) carboxylates as antitumor agnents

Several carboxylates of rhodium(II) were studied with regard to their antitumor properties. The investigations included toxicity studies, survival studies, DNA and RNA synthesis inhibition (in vivo and in vitro), enzyme inhibition studies, and determination of formation constants of rhodium(II) carboxylate/adenosine mono-, di-, and triphosphate complexes. Interactions of rhodium(II) carboxylates with synthetic and natural macromolecules were investigated in order to formulate a possible mechanism of action of these drugs. It was found that even though these drugs differ only slightly in structure, they differ markedly in antitumor, toxic and inhibitory properties when applied to either in vivo or in vitro systems. These differences were explained in two ways: 1) The more potent drugs formed more stable complexes with molecules of biological importance and 2) The more lipophilic drugs were, in general more effective as antitumor agents because of increased permeability into the cell and enzyme active centers.Biology and Biochemistry, Department o