Syntheses, Photochemical Properties, and Tautomerism of Intramolecularly Friedel-Crafts Acylated Hypericin Derivatives

Intramolecularly Friedel-Crafts acylation carried out on the hypericin moiety provided a new class of 9,12-dicarbonyl substituted hypericin derivatives as potential candidates for photodynamic therapy (PDT). Focusing on cyclopentanone and cyclohexanone condensed derivatives, investigations concerning the chemical and photochemical properties as well as the tautomerism of these compounds were performed.