Photoactivation of trans diamine platinum complexes in aqueous solution and effect on reactivity towards nucleotides

J Inorg Biochem. 2010 Sep;104(9):909-18. doi: 10.1016/j.jinorgbio.2010.04.009. Epub 2010 Apr 28.

Abstract

We show that UVA irradiation (365nm) of the Pt(IV) complex trans,trans,trans-[Pt(IV)Cl(2)(OH)(2)(dimethylamine)(isopropylamine)] (1), induces reduction to Pt(II) photoproducts. For the mixed amine Pt(II) complex, trans-[Pt(II)Cl(2)(isopropylamine)(methylamine)] (2), irradiation at 365nm increases the rate and extent of hydrolysis, triggering the formation of diaqua species. Additionally, irradiation increases the extent of reaction of complex 2 with guanosine-5'-monophosphate and affords mainly the bis-adduct, while reactions with adenosine-5'-monophosphate and cytidine-5'-monophosphate give rise only to mono-nucleotide adducts. Density Functional Theory calculations have been used to obtain insights into the electronic structure of complexes 1 and 2, and their photophysical and photochemical properties. UVA-irradiation can contribute to enhanced cytotoxic effects of diamine platinum drugs with trans geometry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemistry
  • Chromatography, Liquid
  • Diamines / chemistry*
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Models, Molecular
  • Molecular Structure
  • Nucleotides / chemistry*
  • Organoplatinum Compounds / chemistry*
  • Photochemistry / methods*

Substances

  • Antineoplastic Agents
  • Diamines
  • Nucleotides
  • Organoplatinum Compounds