Novel analogues of istaroxime, a potent inhibitor of Na+,K+-ATPase: synthesis and structure-activity relationship

J Med Chem. 2008 Aug 14;51(15):4601-8. doi: 10.1021/jm800257s. Epub 2008 Jul 19.

Abstract

We report the synthesis and biological properties of novel inhibitors of the Na(+),K(+)-ATPase as positive inotropic compounds. Following our previously described model from which Istaroxime was generated, the 5alpha,14alpha-androstane skeleton was used as a scaffold to study the space around the basic chain of our lead compound. Some compounds demonstrated higher potencies than Istaroxime on the receptor and the (E)-3-[(R)-3-pyrrolidinyl]oxime derivative, 15, was the most potent; as further confirmation of our model, the E isomers of the oxime are more potent than the Z form. The compounds tested in the guinea pig model induced positive inotropic effects, which are correlated to the in vitro inhibitory potency on the Na(+),K(+)-ATPase. The finding that all tested compounds resulted less proarrhythmogenic than digoxin, a currently clinically used positive inotropic agent, suggests that this could be a feature of the 3-aminoalkyloxime derivative class of 5alpha,14alpha-androstane.

MeSH terms

  • Amines / chemistry
  • Animals
  • Etiocholanolone / analogs & derivatives*
  • Etiocholanolone / chemical synthesis
  • Etiocholanolone / chemistry
  • Etiocholanolone / pharmacology
  • Guinea Pigs
  • Hydroxylation
  • Models, Molecular
  • Molecular Structure
  • Sodium-Potassium-Exchanging ATPase / antagonists & inhibitors*
  • Sodium-Potassium-Exchanging ATPase / metabolism
  • Stereoisomerism
  • Structure-Activity Relationship

Substances

  • Amines
  • Etiocholanolone
  • Sodium-Potassium-Exchanging ATPase
  • Istaroxime