Synthesis, dark toxicity and induction of in vitro DNA photodamage by a tetra(4-nido-carboranylphenyl)porphyrin

J Photochem Photobiol B. 2002 Nov;68(2-3):123-32. doi: 10.1016/s1011-1344(02)00383-4.


The total synthesis of tetra(4-carboranylphenyl)porphyrins 4 and 6 and their zinc(II) complexes 5 and 7 are described. These compounds were characterized by analytical and spectroscopic methods and, in the case of 5, by X-ray crystallography. The water-soluble nido-carboranylporphyrins 6 and 7 were found to have low dark toxicity towards V79 hamster lung fibroblast cells, using a clonogenic assay (50% colony survival, CS(50)>300 microM). Upon light activation nido-carboranylporphyrin 6 effectively induced DNA damage in vitro. Two different methods were used to assess the extent of DNA damage: the super-coiled to nicked DNA and the alkaline Comet assay using human leukemia K562 cells. Significant PDT-induced DNA damage was observed for porphyrin 6 using both assays, compared to light-only and porphyrin-only experiments. It is concluded that this type of nido-carboranylporphyrin is a promising sensitizer for both the boron neutron capture therapy and the photodynamic therapy of tumors.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Line
  • Cell Survival / drug effects
  • Cricetinae
  • Crystallography, X-Ray
  • DNA Damage / drug effects*
  • Darkness
  • Indicators and Reagents
  • Lung / drug effects
  • Lung / pathology
  • Models, Molecular
  • Molecular Conformation
  • Photosensitizing Agents / chemical synthesis
  • Photosensitizing Agents / chemistry*
  • Photosensitizing Agents / toxicity*
  • Porphyrins / chemical synthesis
  • Porphyrins / chemistry*
  • Porphyrins / toxicity*


  • Indicators and Reagents
  • Photosensitizing Agents
  • Porphyrins
  • meso-tetra(4-(o-carboranyl)phenyl)porphyrin