Abstract:
A series of pegylated cis-A2B2- or A3B-type ZnPcs, substituted on the rx-positions with
tri(ethylene glycol) and hydroxyl groups, were synthesized from a new bis-phthalonitrile. A clamshell
type bis-phthalocyanine was also obtained as a byproduct. The hydroxyl group of one ZnPc was alkylated
with 3-dimethylaminopropyl chloride to afford a pegylated ZnPc functionalized with an amine group. All
mononuclear ZnPcs were soluble in polar organic solvents, showed intense Q absorptions in DMF, and
had fluorescence quantum yields in the range 0.10-0.23. The clamshell-type bis-phthalocyanine adopts
mainly open shell conformations in DMF, and closed clamshell conformations in chloroform. All ZnPcs
were highly phototoxic to human carcinoma HEp2 cells, particularly the amino-ZnPc mainly protonated
under physiological conditions, which showed the highest phototoxicity (ICso = 0.5 ~ at 1.5 J/cm2)
and dark cytotoxicity (ICso = 22 I-lM), in part due to its high cellular uptake. The ZnPcs localized in
multiple organelles, including mitochondria, lysosomes, Golgi and ER
