Solution and Solid State Correlations of Antimalarial Drug Actions: NMR and Crystallographic Studies of Drug Interactions with a Heme Model

Inorg Chem. 2017 Jul 17;56(14):7803-7810. doi: 10.1021/acs.inorgchem.7b00526. Epub 2017 Jun 26.

Abstract

Solution NMR has been used in tandem with a diamagnetic non-iron heme model compound as a simple and effective tool to rapidly probe the structures of the bound complexes formed between the metalloporphyrin and antimalarial drugs from the 4-aminoquinoline, 4-methylenehydroxylquinoline, and 8-aminoquinoline subfamilies. The ability of gallium(III) protoporphyrin IX to mimic heme chemistry is exploited. The 4-aminoquinolines quinacrine and amodiaquine and two novel 3-halo chloroquine analogues are found to bind to the metalloporphyrin through hydrogen-bonding and stacking interactions, while halofantrine and the 4-methylenehydroxylquinolines, quinine and mefloquine bind through the alcohol group of the drug. In each case, detailed structural information is available from the NMR assessment. The mefloquine model is confirmed crystallographically. The 8-aminoquinoline primaquine does not interact strongly. These tools show promise for future applications in assessing antimalarials in preclinical development for heme-binding drug targets.

MeSH terms

  • Antimalarials / chemistry*
  • Crystallography, X-Ray
  • Gallium / chemistry
  • Hydrogen Bonding
  • Metalloporphyrins / chemistry*
  • Proton Magnetic Resonance Spectroscopy
  • Protoporphyrins / chemistry*
  • Quinolines / chemistry

Substances

  • Antimalarials
  • Metalloporphyrins
  • Protoporphyrins
  • Quinolines
  • Gallium