Highly positive-charged zinc(II) phthalocyanine as non-aggregated and efficient antifungal photosensitizer.

A new tetra-α-substituted zinc(II) phthalocyanine containing dodeca-amino groups (compound 4) and its quaternized analogue (compound 5) have been prepared and evaluated for their photoactivities against Candida albicans. Compared with the dodeca-amino phthalocyanine 4, the dodeca-cationic phthalocyanine 5 exhibits a higher photodynamic inactivation against C. albicans with an IC90 value down to 1.46 μM, which can be attributed to its non-aggregated nature in aqueous environments and more efficient cellular uptake. More interestingly, 5 shows a higher photodynamic inactivation on C. albicans due to its stronger affinity to C. albicans cells than mammalian cells. These results suggest that the highly positive-charged phthalocyanine 5 is a potential non-aggregated antifungal photosensitizer, which shows some selectivity toward the fungus.