Synthesis and photodynamic activity of a cationic zinc monoazaporphyrin bearing a nitrogen atom at the peripheral position

A new cationic monoazaporphyrin, zinc 2-aza-8,12,13,17-tetraethyl-2,3,7,18-tetramethylporphyrinium iodide 3 was synthesized. Photodynamic activity of 3 in degradation of 2′,3′-isopropylideneguanosine 4 was compared with 2-aza-8,12,13,17-tetraethyl-3,7,18-trimethylporphyrin 1, zinc 2-aza-8,12,13,17-tetraethyl-3,7,18-trimethylporphyrin 2, and hematoporphyrin 5. The quarternary ammonium 3 showed a remarkable increase of photodynamic activity compared with 5, although no appreciable difference in the activity was observed between 1 and 5.