Metal phthalocyanines (MPcs) have been found to be a promising photosensitizers for photodynamic therapy (PDT) of cancers and non-cancer diseases. Nevertheless, phthalocyanines are substantially limited in clinical applications owing to their poor solubility, aggregation and insufficient selectivity for cancer cells. Catechol is an important pharmaceutical intermediate, playing important in vivo biological activity in medicine. Using catechol (pyrocatechin) as axial ligands, utilizing of the pharmaceutical effect of catechins, could improve the bioavailability, and achieve synergistic therapeutic effect in PDT. To address these issues, a novel catechol axially substituted tetra-α-(pentyloxy) titanium(IV) (TiPc(OC₅H₁₁)₄-Catechol) was synthesized. The structure of TiPc(OC₅H₁₁)₄-Catechol was characterized by elemental analysis, IR, ¹HNMR and MS methods. The photophysical properties of TiPc(OC₅H₁₁)₄ and TiPc(OC₅H₁₁)₄-Catechol have been studied by UV/Vis and steady-state fluorescence spectra. After being axially substituted with catechin groups, no obviously intensity and position of maximum wavelength in Q-band of TiPc(OC₅H₁₁)₄ and TiPc(OC₅H₁₁)₄-Catechol were observed. The fluorescence intensity of TiPc(OC₅H₁₁)₄ was stronger than that of TiPc(OC₅H₁₁)₄-Catechol, but the fluorescence lifetime of TiPc(OC₅H₁₁)₄-Catechol was longer than that of TiPc(OC₅H₁₁)₄. TiPc(OC₅H₁₁)₄-Catechol may be considered as a promising photosensitizer for PDT.

Date Published: 31 October 2016
PDF: 5 pages
Proc. SPIE 10024, Optics in Health Care and Biomedical Optics VII, 100243P (31 October 2016); doi: 10.1117/12.2246174

Published in SPIE Proceedings Vol. 10024:
Optics in Health Care and Biomedical Optics VII
Qingming Luo; Xingde Li; Ying Gu; Yuguo Tang, Editor(s)