New halogenated water-soluble chlorin and bacteriochlorin as photostable PDT sensitizers: synthesis, spectroscopy, photophysics, and in vitro photosensitizing efficacy

ChemMedChem. 2010 Oct 4;5(10):1770-80. doi: 10.1002/cmdc.201000223.


Chlorin and bacteriochlorin derivatives of 5,10,15,20-tetrakis(2-chloro-5-sulfophenyl)porphyrin have intense absorptions in the phototherapeutic window, high water solubility, high photostability, low fluorescence quantum yield, long triplet lifetimes, and high singlet oxygen quantum yields. Biological studies revealed their negligible dark cytotoxicity, yet significant photodynamic effect against A549 (human lung adenocarcinoma), MCF7 (human breast carcinoma) and SK-MEL-188 (human melanoma) cell lines upon red light irradiation (cutoff λ<600 nm) at low light doses. Time-dependent cellular accumulation of the chlorinated sulfonated chlorin reached a plateau at 2 h, as previously observed for the related porphyrin. However, the optimal incubation time for the bacteriochlorin derivative was significantly longer (12 h). The spectroscopic, photophysical, and biological properties of the compounds are discussed in relevance to their PDT activity, leading to the conclusion that the bacteriochlorin derivative is a promising candidate for future in vivo experiments.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Halogenation
  • Humans
  • Neoplasms / drug therapy
  • Photochemotherapy
  • Photosensitizing Agents / chemical synthesis
  • Photosensitizing Agents / chemistry*
  • Photosensitizing Agents / therapeutic use
  • Porphyrins / chemistry*
  • Porphyrins / therapeutic use
  • Porphyrins / toxicity
  • Spectrometry, Fluorescence
  • Water / chemistry


  • Photosensitizing Agents
  • Porphyrins
  • bacteriochlorin
  • Water
  • chlorin