The synthesis and characterization of ethylenediamine-modified Elsinochrome A

To overcome the lack of appreciable absorption in the phototherapeutic window (600–900 nm) of the naturally occurring perylenequinonoid pigment, Elsinochrome A, which limits its clinical application, an ethylenediamine-modified elsinochrome A, possessing long wavelength absorption (708 nm) was synthesized. Electron paramagnetic resonance and chemiluminescence assays indicated that ethylenediamine-modified Elsinochrome A possessed photosensitizing activity and its photodamage efficacy is greater than that of unmodified Elsinochrome A.