The effect of the number of carbohydrate moieties on the azaphthalocyanine properties

Dalton Trans. 2012 Sep 21;41(35):10596-604. doi: 10.1039/c2dt30971h. Epub 2012 Jul 26.

Abstract

A series of azaphthalocyanines (AzaPc) bearing one, two, four or eight isopropylidene-protected galactosyl units was prepared by azide-alkyne click reaction or by classical Pc template cyclotetramerization of the corresponding dicyanopyrazine and AzaPc properties important for photodynamic therapy were compared. All compounds absorbed at long wavelengths (above 650 nm) and belonged to strong singlet oxygen producers (Φ(Δ) = 0.58-0.64) retaining significant fluorescence emission (Φ(F) = 0.026-0.23). The only exception was the compound with four isopropyliden-protected galactosyl units where partial aggregation was observed. Removal of protecting groups increased the polar character of all AzaPc. However, only AzaPc bearing eight galactoses was found to be water-soluble (105 mg mL(-1)) but noticeably aggregated in water as well as in organic solvents (DMF, DMSO). Amphiphilic AzaPc bearing one deprotected galactose was incorporated into the lipidic bilayer of liposomes in a nonaggregated form. Liposomes may therefore be a suitable delivery system for this amphiphilic photosensitizer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbocyanines / chemical synthesis
  • Carbocyanines / chemistry*
  • Galactose / chemistry*
  • Lipid Bilayers / chemistry
  • Liposomes / chemistry
  • Photosensitizing Agents / chemical synthesis
  • Photosensitizing Agents / chemistry*
  • Singlet Oxygen / chemistry
  • Solvents / chemistry
  • Spectrophotometry, Ultraviolet
  • Water / chemistry

Substances

  • Carbocyanines
  • Lipid Bilayers
  • Liposomes
  • Photosensitizing Agents
  • Solvents
  • Water
  • Singlet Oxygen
  • Galactose