Trioxsalens, also known as psoralens, are physiological photosensitizing agents historically used to alter human skin pigmentation. At the molecular level, psoralens intercalate into double-stranded DNA. Irradiation induces monosubstitution of pyrimidine bases. If efficiency is high, double substitution and bridging will occur. Designed to bind tightly within the DNA helix to improve substitution yields during irradiation. Inactivates DNA and RNA viruses, including HIV-1, by inducing nucleic acid cross-linking followed by UV irradiation.
