Cisplatin is an antitumor metal complex known for its high activity and clinical use. However, its serious side effects have conducted research into new complex designs with less toxicity and greater antitumor efficacy. Currently, there are antitumor therapies that use irradiation as a method of activating chemical compounds to increase their activity and thus control them within the system. Photochemical therapy (PACT) is of particular interest, since it allows this control in drugs temporarily and spatially
An alternative in the development of metal antitumor complexes is the formation of complexes containing ligands with "cis/trans" photochemical isomerization capacity due to the presence of the azo group (-N=N-). This fact offers the possibility of a photochemical control in the antitumor activity of these types of compounds.
Within this frame, we have synthetized and characterized ligands which carry an azo group in their structures. We have also tested and studied the reactions of these ligands with platinum(II) salts to give the corresponding platinum complexes. The photochemical properties and the effect of the solvents on the structure of the azo compounds and the complexes have been studied by Nuclear Magnetic Resonance and UV-vis spectroscopy. The preliminary results evidence that the platinum complexes undergo trans-cis isomerization upon irradiation, and the cis isomers then undergo slow thermal isomerization back to the more stable trans isomers. Thus, this synthetic route and design could be a promising strategy to obtain photoactivable prodrugs to use in Phototherapy for cancer treatment.