Abstract:
An isothiocyanato-functionalized phthalocyanine (Pc) was synthesized in good yield
from the corresponding amine-substituted Pc. This Pc reacted with ethanolamine, biotin hydrazine, and
biotin diethylamine under mild conditions (room temperature in DMF or DMSO in the presence of TEA)
to produce the corresponding thiourea products in 60–75% yields. All Pcs showed intense Q absorptions
in DMF around 677 nm, emissions centered at 683 nm, and fluorescence quantum yields in the range
0.18–0.27. The Pcs were phototoxic to human carcinoma HEp2 cells (IC50 ~ 7 at 1.5 J/cm2
) and localized
in multiple organelles, including the lysosomes, Golgi and ER. One biotin-Pc conjugate was injected
via tail vein into nude mice bearing HT-29 tumors and demonstrated selective localization in the tumor
tissue.