A set of highly water-soluble tetraethyleneglycol-substituted Zn(II) phthalocyanines: synthesis, photochemical and photophysical properties, interaction with plasma proteins and in vitro phototoxicity

Dalton Trans. 2011 Apr 28;40(16):4067-79. doi: 10.1039/c0dt01260b. Epub 2010 Dec 14.


Three Zn(II) phthalocyanines substituted by hydroxyl-terminated tetraethylene glycol chains have been synthesized. In order to evaluate the potential of these highly water-soluble phthalocyanines as type II-photosensitisers for photodynamic therapy, their structure-activity relationship was assessed by determining relevant photophysical and photochemical properties, such as their aggregation behaviour in aqueous buffers, their fluorescence properties and their efficiency with regard to the generation of singlet oxygen. In addition, evidence for a negligible interaction with plasma proteins in undiluted human plasma was obtained using a recently developed bioanalytical method and compared with the fluorescence quenching approach. These results combined with in vitro data regarding the phototoxicity of these phthalocyanines against HT-29 cancer cells provide evidence for the relevance of the non-peripherally substituted derivative for further in vivo investigations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption
  • Animals
  • Blood Proteins / metabolism*
  • Cattle
  • Drug Design
  • HT29 Cells
  • Humans
  • Indoles / chemical synthesis*
  • Indoles / chemistry
  • Indoles / metabolism*
  • Indoles / pharmacology
  • Organometallic Compounds / chemical synthesis*
  • Organometallic Compounds / chemistry
  • Organometallic Compounds / metabolism*
  • Organometallic Compounds / pharmacology
  • Photochemical Processes*
  • Photosensitizing Agents / chemical synthesis
  • Photosensitizing Agents / chemistry
  • Photosensitizing Agents / metabolism
  • Photosensitizing Agents / pharmacology
  • Polyethylene Glycols / chemistry*
  • Protein Binding
  • Serum Albumin, Bovine / metabolism
  • Singlet Oxygen / chemistry
  • Solubility
  • Water / chemistry*


  • Blood Proteins
  • Indoles
  • Organometallic Compounds
  • Photosensitizing Agents
  • Water
  • Zn(II)-phthalocyanine
  • Singlet Oxygen
  • Serum Albumin, Bovine
  • Polyethylene Glycols