Evaluation of DNA-binding and DNA-photocleavage ability of tetra-cationic porphyrins containing peripheral [Ru(bpy)2Cl]+ complexes: Insights for photodynamic therapy agents

J Photochem Photobiol B. 2020 Oct:211:111991. doi: 10.1016/j.jphotobiol.2020.111991. Epub 2020 Aug 11.

Abstract

The present work reports the spectroscopic and theoretical evaluation of the interaction between calf-thymus DNA (CT-DNA) and free-base meso-tetra-(ruthenated) porphyrin (H2RuTPyP) or its corresponding Zn(II) complex (ZnRuTPyP). Spectroscopic measurements (UV-vis, circular dichroism and steady-state fluorescence emission) combined with theoretical molecular docking calculations suggest that Ru(II)-porphyrins interact with the DNA backbone by external mode via electrostatic forces. In addition, gel electrophoresis analysis demonstrate that these porphyrins promote efficient plasmidial DNA photocleavage upon white-light irradiation conditions, indicating H2RuTPyP and ZnRuTPyP as potential candidates for photodynamic therapy.

Keywords: Cationic porphyrins; DNA-binding; Photocleavage assays; Photodynamic therapy (PDT); Tetra-ruthenated porphyrins.

MeSH terms

  • Cations / chemistry
  • Coordination Complexes / chemistry*
  • Coordination Complexes / pharmacology
  • DNA / radiation effects*
  • DNA Cleavage / radiation effects*
  • Free Radical Scavengers / chemistry
  • Light
  • Molecular Docking Simulation
  • Photochemotherapy
  • Photosensitizing Agents / chemistry*
  • Photosensitizing Agents / pharmacology
  • Porphyrins / chemistry*
  • Reactive Oxygen Species / chemistry
  • Ruthenium / chemistry*
  • Static Electricity
  • Structure-Activity Relationship
  • Zinc / chemistry*

Substances

  • Cations
  • Coordination Complexes
  • Free Radical Scavengers
  • Photosensitizing Agents
  • Porphyrins
  • Reactive Oxygen Species
  • Ruthenium
  • DNA
  • calf thymus DNA
  • Zinc