Activation of the NLRP3 Inflammasome by Hyaboron, a New Asymmetric Boron-Containing Macrodiolide from the Myxobacterium Hyalangium minutum

ACS Chem Biol. 2018 Oct 19;13(10):2981-2988. doi: 10.1021/acschembio.8b00659. Epub 2018 Sep 17.


A Natural Compound Library containing myxobacterial secondary metabolites was screened in murine macrophages for novel activators of IL-1β maturation and secretion. The most potent of three hits in total was a so far undescribed metabolite, which was identified from the myxobacterium Hyalangium minutum strain Hym3. While the planar structure of 1 was elucidated by high resolution mass spectrometry and NMR data yielding an asymmetric boron containing a macrodiolide core structure, its relative stereochemistry of all 20 stereocenters of the 42-membered ring was assigned by rotating frame Overhause effect spectroscopy correlations, 1H,1H, and 1H,13C coupling constants, and by comparison of 13C chemical shifts to those of the structurally related metabolites tartrolon B-D. The absolute stereochemistry was subsequently assigned by Mosher's and Marfey's methods. Further functional studies revealed that hyaboron and other boronated natural compounds resulted in NLRP3 inflammasome dependent IL-1β maturation, which is most likely due to their ability to act as potassium ionophores. Moreover, besides its inflammasome-stimulatory activity in human and mouse cells, hyaboron (1) showed additional diverse biological activities, including antibacterial and antiparasitic effects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / chemistry
  • Adjuvants, Immunologic / pharmacology*
  • Animals
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Antifungal Agents / chemistry
  • Antifungal Agents / pharmacology
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology
  • Boron Compounds / chemistry
  • Boron Compounds / pharmacology*
  • Cell Line, Tumor
  • Fungi / drug effects
  • Gram-Positive Bacteria / drug effects
  • Humans
  • Inflammasomes / metabolism
  • Macrolides / chemistry
  • Macrolides / pharmacology*
  • Mice
  • Myxococcales / chemistry*
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • Small Molecule Libraries / chemistry
  • Stereoisomerism


  • Adjuvants, Immunologic
  • Anti-Bacterial Agents
  • Antifungal Agents
  • Antineoplastic Agents
  • Boron Compounds
  • Inflammasomes
  • Macrolides
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Small Molecule Libraries