Iron(III) catecholates for cellular imaging and photocytotoxicity in red light

Chem Asian J. 2014 Sep;9(9):2494-504. doi: 10.1002/asia.201402207. Epub 2014 Jul 14.

Abstract

Iron(III) complexes [Fe(L)(L')(NO3)]--in which L is phenyl-N,N-bis[(pyridin-2-yl)methyl]methanamine (1), (anthracen-9-yl)-N,N-bis[(pyridin-2-yl)methyl]methanamine (2), (pyreny-1-yl)-N,N-bis[(pyridin-2-yl)methyl]methanamine (3-5), and L' is catecholate (1-3), 4-tert-butyl catecholate (4), and 4-(2-aminoethyl)-benzene-1,2-diolate (5)--were synthesized and their photocytotoxic properties examined. The five electron-paramagnetic complexes displayed a Fe(III)/Fe(II) redox couple near -0.4 V versus a saturated calomel electrode (SCE) in DMF/0.1 M tetrabutylammonium perchlorate (TBAP). They showed unprecedented photocytotoxicity in red light (600-720 nm) to give IC50≈15 μM in various cell lines by means of apoptosis to generate reactive oxygen species. They were ingested in the nucleus of HeLa and HaCaT cells in 4 h, thereby interacting favorably with calf thymus (ct)-DNA and photocleaving pUC19 DNA in red light of 785 nm to form hydroxyl radicals.

Keywords: DNA cleavage; apoptosis; bioinorganic chemistry; iron; photocytotoxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Catechols / chemistry*
  • Cattle
  • Color*
  • Crystallography, X-Ray
  • DNA / chemistry*
  • DNA / drug effects
  • DNA / radiation effects*
  • DNA Cleavage
  • Ferrous Compounds / chemical synthesis
  • Ferrous Compounds / chemistry*
  • Ferrous Compounds / pharmacology
  • HeLa Cells
  • Humans
  • Light*
  • Models, Molecular
  • Molecular Imaging / methods*
  • Molecular Structure
  • Photochemical Processes
  • Photosensitizing Agents / chemical synthesis
  • Photosensitizing Agents / chemistry*
  • Photosensitizing Agents / pharmacology
  • Plasmids / chemistry
  • Plasmids / drug effects
  • Plasmids / radiation effects
  • Quantum Theory
  • Reactive Oxygen Species / metabolism

Substances

  • Catechols
  • Ferrous Compounds
  • Photosensitizing Agents
  • Reactive Oxygen Species
  • DNA