Synthesis, spectroscopic, and cellular properties of α-pegylated cis-A2B2- and A3B-types ZnPcs.

Abstract

A series of pegylated cis-A2B2- or A3B-type ZnPcs, substituted on the α-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 (IC50 = 0.5 μM at 1.5 J/cm2) and dark cytotoxicity (IC50 = 22 μM), in part due to its high cellular uptake. The ZnPcs localized in multiple organelles, including mitochondria, lysosomes, Golgi and ER.

• Authors: Benson G Ongarora, Zehua Zhou, Elizabeth A Okoth, Igor Kolesnichenko, Kevin M Smith, M Graça H Vicente
• Journal: Journal of porphyrins and phthalocyanines (J Porphyr Phthalocyanines) 2014 Oct-Nov Vol. 18 Issue 10-11 Pg. 1021-1033 ISSN: 1088-4246 [Print] Singapore
• PMID: 26064037 (Publication Type: Journal Article)