PHOTOCYTOTOXICITY OF WATER-SOLUBLE METALLOPORPHYRIN DERIVATIVES

A new water-soluble porphyrin derivative, -decyloxyethyl)-deuteroporph yrinyl-6,7-bisaspartic acid (C10-DP), and its metal complexes (Ga, In, Sn, Zn, Mn, Cu, Ni and Fe) were examined for their physicochemical pr operties (absorption, fluorescence, triplet lifetime and partition coe fficient) and photocytotoxicity on HeLa cells. The five derivatives wi th longer (> 1 ms) triplet lifetimes (free base, Zn, Ga, In and Sn com plexes) exhibited remarkable photocytotoxicity, and the other derivati ves (Mn, Cu, Ni and Fe), which had or were deduced to have fairly shor t (< 0.01 ms) triplet lifetimes, manifested no photocytotoxicity, indi cating that the triplet lifetime of these derivatives played a signifi cant role in their photocytotoxicity. Cellular fluorescence due to C10 -DP and its gallium complex was observed mainly on the plasma membrane at the concentrations showing significant photocytotoxicity with low (< 32.6%) cytotoxicity in the dark (2-10 muM).