Importance of the orthogonal structure between porphyrin and aniline moieties on the pH-activatable porphyrin derivative for photodynamic therapy

The photo-induced side effects of photodynamic therapy of cancer can be suppressed using pH-activatable porphyrin derivatives, which have been developed using an aniline moiety as a pH-responsive quencher. The acid dissociation coefficient of a pH-activatable photosensitizer increased by replacing a dimethylamino with a diethylamino group. Based on this diethylamino derivative, we studied the importance of the intramolecular orthogonal structure...