The aim of the present project is to
study the photochemical reactivity of the APAs with DNA. Tiaprofenic acid will be used as a representative member of the APAs family, and selected DNA fragments will be employed as models for the polymeric biomolecule. To be studied: The eletron transfer pathway: The possibility of DNA damage via electron transfer to excited TPA will be investigated using dG as model compound.
The energy transfer pathway: The TPA-photosensitized dimerization of thymine will be studied as a model reaction for the energy transfer pathway.
The singlet oxygen pathway: The possible involvement of a type II mechanism in the TPA-photosensitized DNA damage will be investigated by using deoxyguanosine as a probe.
The hydroxyl radical pathway: The TPA-photosensitized reactions of the thymine will be performed under aerobic conditions, in order to detect the possible formation of such radical intermediates through the identification of the oxidation products arising from oxygen trapping.