Umbelliferone Decorated Water-soluble Zinc(II) Phthalocyanines - In Vitro Phototoxic Antimicrobial Anti-cancer Agents

Sowa A, Höing A, Dobrindt U, Knauer SK, Galstyan A, Voskuhl J

Abstract

In this contribution we report on the synthesis, characterization and application of water-soluble zinc(II) phthalocyanines which are decorated with four or eight umbelliferone moieties for photodynamic therapy (PDT). These compounds are linked peripherally to zinc(II) phthalocyanine by a tri(ethylene glycol) linker attached to pyridines, leading to cationic pyridinium units, able to increase the water solubility of the system. Beside their photophysical properties they were analyzed concerning their cellular distribution in human hepatocyte carcinoma (HepG2) cells as well as their phototoxicity towards HepG2 cells, Gram-positive (S. aureus 3150/12 and B. subtilis DB104) and Gram-negative bacteria (E. coli UTI89 and E. coli Nissle 1917). At low light doses and concentrations, they exhibit superb antimicrobial activity against Gram-positive bacteria as well as anti-tumor activity against HepG2. They are even capable to inactivate Gram-negative bacteria, whereas the dark toxicity remains low. These unique water-soluble compounds can be regarded as all-in-one type photosensitizers with broad applications ranges in the future.