Photophysics and photochemistry of pterins in aqueous solution.

Pterins belong to a family of heterocyclic compounds present in a wide range of living systems and participate in relevant biological functions. Interest in the photochemistry and photophysics of this group of compounds has increased since the participation of pterin derivatives in different photobiological processes has been suggested or demonstrated in recent decades. This account describes and connects basic studies on the fluorescence emission, the photooxidation, and the photosensitizing properties of oxidized six-substituted pterins in aqueous solution under UV-A irradiation. The biological implications of these studies are also discussed.