Structure-activity relationship studies on 1-(2-oxopropyl)indole-5-carboxylic acids acting as inhibitors of cytosolic phospholipase A2α: Effect of substituents at the indole 3-position on activity, solubility, and metabolic stability

Eur J Med Chem. 2017 Jan 5:125:1107-1114. doi: 10.1016/j.ejmech.2016.10.039. Epub 2016 Oct 21.

Abstract

Cytosolic phospholipase A2α (cPLA2α) is a key enzyme in the biosynthesis of pro-inflammatory lipid mediators and therefore represents an attractive target for the development of new anti-inflammatory drugs. Recently, we have found that 1-[3-(4-octylphenoxy)-2-oxopropyl]indole-5-carboxylic acid (4) is a potent inhibitor of the enzyme. In this work, we evaluate the effect of butanoyl- and hexanoyl-substituents in position 3 of the indole scaffold of this compound bearing terminal groups of varying polarity. As a result, inhibitory potency was not affected considerably in most cases, while metabolic phase I and phase II in vitro stability and aqueous solubility could be influenced and modulated by the structural modifications performed.

Keywords: Aqueous solubility; Cytosolic phospholipase A(2)α; Glucuronidation; Indole derivatives; Inhibitors; Ketone reduction; Metabolic stability.

MeSH terms

  • Animals
  • Blood Platelets / drug effects
  • Blood Platelets / enzymology
  • Carboxylic Acids / chemistry
  • Carboxylic Acids / metabolism
  • Carboxylic Acids / pharmacology
  • Group IV Phospholipases A2 / antagonists & inhibitors*
  • Group IV Phospholipases A2 / metabolism
  • Humans
  • Indoles / chemistry*
  • Indoles / metabolism
  • Indoles / pharmacology*
  • Liver / metabolism
  • Mice
  • Phospholipase A2 Inhibitors / chemistry*
  • Phospholipase A2 Inhibitors / metabolism
  • Phospholipase A2 Inhibitors / pharmacology*
  • Rats
  • Solubility
  • Structure-Activity Relationship

Substances

  • Carboxylic Acids
  • Indoles
  • Phospholipase A2 Inhibitors
  • Group IV Phospholipases A2