Structure-based optimization and biological evaluation of human 20α-hydroxysteroid dehydrogenase (AKR1C1) salicylic acid-based inhibitors

Eur J Med Chem. 2010 Nov;45(11):5309-17. doi: 10.1016/j.ejmech.2010.08.052. Epub 2010 Sep 17.


The tertiary structure of the Leu308Val mutant of human 20α-hydroxysteroid dehydrogenase (AKR1C1) in complex with the inhibitor 3,5-dichlorosalicylic acid (DCL) has been determined. Structures and kinetic properties of the wild-type and mutant enzymes indicate that Leu308 is a selectivity determinant for inhibitor binding. The Leu308Val mutation resulted in 13-fold and 3-fold reductions in the inhibitory potencies of DCL and 3-bromo-5-phenylsalicylic acid (BPSA), respectively. The replacement of Leu308 with an alanine resulted in 473-fold and 27-fold reductions in the potencies for DCL and BPSA, respectively. In our attempts to optimize inhibitor potency and selectivity we synthesized 5-substituted 3-chlorosalicylic acid derivatives, of which the most potent compound, 3-chloro-5-phenylsalicylic acid (K(i) = 0.86 nM), was 24-fold more selective for AKR1C1 relative to the structurally similar 3α-hydroxysteroid dehydrogenase (AKR1C2). Furthermore, the compound inhibited the metabolism of progesterone in AKR1C1-overexpressed cells with an IC(50) value equal to 100 nM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 20-Hydroxysteroid Dehydrogenases / antagonists & inhibitors*
  • 20-Hydroxysteroid Dehydrogenases / genetics
  • Animals
  • Cattle
  • Cells, Cultured
  • Crystallization
  • Enzyme Inhibitors / chemistry*
  • Enzyme Inhibitors / pharmacology*
  • Humans
  • Inhibitory Concentration 50
  • Kinetics
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Structure
  • Mutagenesis, Site-Directed
  • Recombinant Proteins / antagonists & inhibitors
  • Recombinant Proteins / genetics
  • Salicylic Acid / chemistry*
  • Salicylic Acid / pharmacology*
  • Spectrometry, Mass, Electrospray Ionization
  • Structure-Activity Relationship


  • Enzyme Inhibitors
  • Recombinant Proteins
  • 20-Hydroxysteroid Dehydrogenases
  • 3 alpha-beta, 20 beta-hydroxysteroid dehydrogenase
  • Salicylic Acid