Synthesis of novel functionalised zinc phthalocyanines applicable in photodynamic therapy

The synthesis of several new phthalonitriles 3, 9, 14, 25, 33, and 36, func tionalised with carboxyl groups, including two examples of amino acid deriv atives is described. All new phthalonitriles were converted into their corr esponding phthalocyaninatozinc compounds. The phthalocyanines, 2,3,9,10,16, 17,23,24-octa(1-carboxyethyloxy)phthalocyaninatozinc (5), 2,9,16,23-tetra(2 -amino-2-carboxyethyl)phthalocyaninatozinc (11), 2,9,16,23-tetra(1-carboxy- 2-hydroxyethyl- aminocarbonyl)phthalocyaninatozinc (16), 1,8,15,22-tetra(ca rboxybutyl)phthalocyaninatozinc (27), 2,3,9,10,16,17,23,24-octa(carboxyalky l)phthalocyaninatozinc (39), and the noniden-tically substituted 9,10,16,17 ,23,24-hexa(carboxyalkyl)-2-[4-(N-succinimidyloxycarbonyl)butyl]phthaloyani natozinc (41) are all sufficiently soluble in water. The nonidentically-sub stituted compounds are important due to their selective binding to tumor-se lective antibodies. UV/Vis-spectroscopy was used to investigate the effect of more or less sterically-demanding substituents in the periphery of the p hthalocyanines towards aggregation. The phototoxicity towards cancer cells of some of the new compounds was investigated in several in-vitro experimen ts.