Photophysics, photochemistry and photobiology of hypocrellin photosensitizers

Hypocrellins are novel photosensitizers from China, which are demonstrated to have significant anti- tumor and anti-virus activity and to be potential photo- dynamic therapy (PDT) agents. As compared with hemato- porphyrin, the only approved photosensitizer, hypocrellins have several advantages, such as easy preparation and easy purification, high triplet quantum yield, high singlet-oxygen quantum yield, high phototoxicity but low dark toxicity, and rapid clearance from normal issues. This article reviews briefly the photophysics, photochemistry and photobiology of hypocrellins on the basis of the domestic and international research results.