THE LIPID SOLUBILITY OF PORPHYRINS MODULATES THEIR PHOTOTOXICITY IN MEMBRANE MODELS

Abstract
The photosensitizing activities of hematoporphyrin, Cu‐hematoporphyrin, protoporphyrin. Zn‐protoporphyrin, deuteroporphyrin and uroporphyrin are studied. The relative yields of1O2are measured in buffer (pH 8.0) and compared to the yields of Type II photodamages induced on cholesterol embedded in egg lecithin liposomes. Results show that the solubilization of the sensitizer in the lipid bilayer is a prerequisite for its photosensitizing activity at the membrane level. In this context, the partition coefficient represents an important parameter.