Laser flash photolysis of purpurins: novel potential photosensitizers of interest in photodynamic therapy.

Purpurins, a new class of photosensitizers of potential use in the photodynamic therapy of cancer, have been studied by laser spectroscopy to determine the properties of their excited states. For the two molecules studied, generation of triplet states and singlet oxygen (1O2) is very efficient. Singlet oxygen yields are presented for red and blue excitation though no significant wavelength effect is apparent. The promise these sensitizers have shown merits further investigation of other derivatives.