Preparation and In Vitro Photodynamic Activity of Glucosylated Zinc(II) Phthalocyanines as Underlying Targeting Photosensitizers

Abstract

Two novel glucosylated zinc(II) phthalocyanines 7a–7b, as well as the acetyl-protected counterparts 6a–6b, have been synthesized by the Cu(I)-catalyzed 1,3-dipolar cycloaddition between the propargylated phthalocyanine and azide-substituted glucoses. All of these phthalocyanines were characterized with various spectroscopic methods and studied for their photo-physical, photo-chemical, and photo-biological properties. With glucose as the targeting unit, phthalocyanines 7a–7b exhibit a specific affinity to MCF-7 breast cancer cells over human embryonic lung fibroblast (HELF) cells, showing higher cellular uptake. Upon illumination, both photosensitizers show high cytotoxicity with IC50 as low as 0.032 µM toward MCF-7 cells, which are attributed to their high cellular uptake and low aggregation tendency in the biological media, promoting the generation of intracellular reactive oxygen species (ROS). Confocal laser fluorescence microscopic studies have also revealed that they have high and selective affinities to the lysosomes, but not the mitochondria, of MCF-7 cells. The results show that these two glucosylated zinc(II) phthalocyanines are potential anticancer agents for targeting photodynamic therapy.

Trifluoromethyl Boron Dipyrromethene Derivatives as Potential Photosensitizers for Photodynamic Therapy

“…Upon excitation at 610 nm, BDP3 and BDP6 show a narrow fluorescence emission at 662 and 661 nm, respectively. The fluorescence quantum yields (Φ F ) were determined to be 017 and 0.16 by using unsubstituted zinc(II) phthalocyanine (ZnPc) (Φ F = 0.28) as the standard compound ( Table 1 ) [ 18 ]. To evaluate the photosensitizing potential, the singlet oxygen quantum yields (Φ Δ ) of these two BODIPY derivatives were also determined in DMF by a steady-state method using 1,3-diphenylisobenzofuran (DPBF) as the singlet oxygen scavenger and ZnPc as the standard.…”

“…Nowadays, the photosensitizers used in clinical practice are mainly tetrapyrrole macrocycles such as porphyrin [ 1 , 14 ], chlorin [ 15 ], and phthalocyanine [ 16 , 17 ]. However, the drawbacks of this class of molecules are the cumbersome synthesis and purification processes [ 18 , 19 ].…”

α- and β-Substituted Metal-Free Phthalocyanines: Synthesis, Photophysical and Electrochemical Properties

“…UV-Vis spectra of the compounds 4 and 5 at different concentrations were recorded in DCM (a series of spectra can be seen in Figure 2 for compound 5). The Q-band intensity of 4 and 5 increased by increasing concentration and no new bands were observed [40].…”

Azides and Porphyrinoids: Synthetic Approaches and Applications. Part 2—Azides, Phthalocyanines, Subphthalocyanines and Porphyrazines

“…A silicon(IV) phthalocyanine bearing two axial sugar units SiPc20 was synthesized as illustrated in Scheme 13. Using a base-catalyzed ligand exchange approach, the silicon(IV) phthalocyanine dichloride SiPc18 in the presence of hex-5-yn-1-ol afforded the silicon dialkyne Liu and co-workers also used azide-substituted glucose derivatives to prepare the acetylated glucosyl phthalocyanines ZnPc16a and ZnPc16b and the glucosyl ones ZnPc17a and ZnPc17b using the propargylated phthalocyanine ZnPc15 (Scheme 12) [30]. The cycloaddition reaction was done in both cases in the presence of CuSO4•5H2O and sodium ascorbate, at room temperature, affording the expected conjugates ZnPc16 and ZnPc17.…”