Hypocrellin B

Hypocrellin A (HA) and hypocrellin B (HB) are peryloquinones isolated from the fungi Hypocrella bambusae (B. et Br) Sacc. and Shiraia bambusicola P. Heen. These pigments have been used in combination with phototherapy to treat various skin diseases. Recently, they have been found to have antiviral activity and are potent photosensitizers in photodynamic therapy of cancer [1-3]. HA was found to have photoinduced antiviral activity against vesicular stomatitis virus and HIV type I [4]. The antiviral activity is oxygen dependent. Singlet oxygen is most likely involved n the virus inactivation [5]. Singlet oxygen and other radical species are also responsible for the photodynamic therapy of tumors using HA and HB as photosensitizers [6, 7]. Many water soluble derivatives of hypocrellins have been synthetized to enhance the photosensitizing efiicacy in cancer PDT and a few have been in preclinical trial [8, 9].