Aromatic thioglycoside inhibitors against the virulence factor LecA from Pseudomonas aeruginosa

Org Biomol Chem. 2013 Sep 25;11(40):6906-18. doi: 10.1039/c3ob41422a.


Three small families of hydrolytically stable thioaryl glycosides were prepared as inhibitors of the LecA (PA-IL) virulence factor corresponding to the carbohydrate binding lectin from the bacterial pathogen Pseudomonas aeruginosa. The monosaccharidic arylthio β-d-galactopyranosides served as a common template for the major series that was also substituted at the O-3 position. Arylthio disaccharides from lactose and from melibiose constituted the other two series members. In spite of the fact that the natural ligand for LecA is a glycolipid of the globotriaosylceramide having an α-d-galactopyranoside epitope, this study illustrated that the β-d-galactopyranoside configuration having a hydrophobic aglycon could override the requirement toward the anomeric configuration of the natural sugar. The enzyme linked lectin assay together with isothermal titration microcalorimetry established that naphthyl 1-thio-β-d-galactopyranoside () gave the best inhibition with an IC50 twenty-three times better than that of the reference methyl α-d-galactopyranoside. In addition it showed a KD of 6.3 μM which was ten times better than that of the reference compound. The X-ray crystal structure of LecA with was also obtained.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adhesins, Bacterial / metabolism*
  • Dose-Response Relationship, Drug
  • Models, Molecular
  • Molecular Structure
  • Pseudomonas aeruginosa / chemistry*
  • Structure-Activity Relationship
  • Thioglycosides / chemical synthesis
  • Thioglycosides / chemistry
  • Thioglycosides / pharmacology*


  • Adhesins, Bacterial
  • LecA protein, bacteria
  • Thioglycosides