Mechanistic Insight on the Mode of Action of Colletoic Acid

J Med Chem. 2019 Aug 8;62(15):6925-6940. doi: 10.1021/acs.jmedchem.9b00187. Epub 2019 Jul 24.


The natural product colletoic acid (CA) is a selective inhibitor of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which primarily converts cortisone to the active glucocorticoid (GC) cortisol. Here, CA's mode of action and its potential as a chemical tool to study intracellular GC signaling in adipogenesis are disclosed. 11β-HSD1 biochemical studies of CA indicated that its functional groups at C-1, C-4, and C-9 were important for enzymatic activity; an X-ray crystal structure of 11β-HSD1 bound to CA at 2.6 Å resolution revealed the nature of those interactions, namely, a close-fitting and favorable interactions between the constrained CA spirocycle and the catalytic triad of 11β-HSD1. Structure-activity relationship studies culminated in the development of a superior CA analogue with improved target engagement. Furthermore, we demonstrate that CA selectively inhibits preadipocyte differentiation through 11β-HSD1 inhibition, suppressing other relevant key drivers of adipogenesis (i.e., PPARγ, PGC-1α), presumably by negatively modulating the glucocorticoid signaling pathway. The combined findings provide an in-depth evaluation of the mode of action of CA and its potential as a tool compound to study adipose tissue and its implications in metabolic syndrome.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 11-beta-Hydroxysteroid Dehydrogenase Type 1 / antagonists & inhibitors
  • 11-beta-Hydroxysteroid Dehydrogenase Type 1 / chemistry*
  • 11-beta-Hydroxysteroid Dehydrogenase Type 1 / metabolism*
  • 3T3-L1 Cells
  • Animals
  • Crystallography, X-Ray / methods
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / metabolism
  • Enzyme Inhibitors / pharmacology
  • HEK293 Cells
  • Hep G2 Cells
  • Humans
  • Mice
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Protein Structure, Tertiary
  • Sesquiterpenes / chemistry*
  • Sesquiterpenes / metabolism*
  • Sesquiterpenes / pharmacology


  • Enzyme Inhibitors
  • Sesquiterpenes
  • colletoic acid
  • 11-beta-Hydroxysteroid Dehydrogenase Type 1