Oxidation of biomolecules photosensitized by pterin derivatives

DANTOLA, MARIA LAURA; VIGNONI, MARIANA; SERRANO, MARIANA P; LORENTE, CAROLINA; THOMAS, ANDRÉS H.

Anales de la Asociación Química Argentina

Asociación Química Argentina

Año: 2020

2545-8655

The biological and medical importance of photosensitized reactions is mainly related to their participation in processes involved in the development of skin cancer and in photodynamic treatments against cancer and infections. Pterins, a family of heterocyclic compounds derived from 2-aminopteridin-4(1H)-one, are widespread in living systems and participate in important biological functions. In pathological conditions, such as vitiligo, oxidized pterins accumulate in the white skin patches of patients suffering this depigmentation disorder. These molecules are photochemically active and, under UV-A excitation (320?400 nm), they can fluoresce, produce organic radicals and reactive oxygen species and undergo photooxidation. Our research group has investigated for more than 20 years, the degradation of biomolecules such as DNA, proteins, lipids, and their components, photosensitized by pterins under UV-A irradiation. The experimental results include kinetics analysis, evaluation of interaction between pterins excited states with different substrates, detection of radical species, and identification of products, under different experimental conditions. Depending on the target molecule, pterin-photosensitized oxidations may be purely type I (electron transfer) or type II (singlet oxygen, 1O2), or a combination of both. In this article, we present a summary of the chemical changes photoinduced by pterins upon UV-A irradiation in different biomolecules and the mechanisms involved.