Design, synthesis, and biological evaluation of α-hydroxyacyl-AMS inhibitors of amino acid adenylation enzymes

• Published in: Bioorganic & medicinal chemistry letters Vol. 26; no. 21; pp. 5340 - 5345
• Main Authors: Davis, Tony D., Mohandas, Poornima, Chiriac, Maria I., Bythrow, Glennon V., Quadri, Luis E.N., Tan, Derek S.
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.11.2016; Elsevier
• Subjects: Adenosine - analogs & derivatives; Adenosine - chemical synthesis; Adenosine - pharmacology; Adenylation; Amino Acids - metabolism; Antibiotic; Chemistry; Chemistry, Medicinal; Chemistry, Organic; Enzyme Inhibitors - chemical synthesis; Enzyme Inhibitors - chemistry; Enzyme Inhibitors - pharmacology; Life Sciences & Biomedicine; Non-ribosomal peptide synthetase; Peptide Synthases - antagonists & inhibitors; Pharmacology & Pharmacy; Physical Sciences; Rational design; Science & Technology; Structure-Activity Relationship; Virulence; Antibiotic; Rational design; Adenylation; Non-ribosomal peptide synthetase; Virulence; MYCOBACTERIUM-TUBERCULOSIS; BISUBSTRATE INHIBITORS; ESCHERICHIA-COLI; VIRULENCE FACTOR; SIDEROPHORE BIOSYNTHESIS; COA SYNTHETASE; TARGETING VIRULENCE; TRANSFER-RNA SYNTHETASE; STRUCTURAL BASIS; SMALL-MOLECULE INHIBITION
• ISSN: 0960-894X; 1464-3405
• DOI: 10.1016/j.bmcl.2016.09.027

[Display omitted] Biosynthesis of bacterial natural-product virulence factors is emerging as a promising antibiotic target. Many such natural products are produced by nonribosomal peptide synthetases (NRPS) from amino acid precursors. To develop selective inhibitors of these pathways, we have previously described aminoacyl-AMS (sulfamoyladenosine) macrocycles that inhibit NRPS amino acid adenylation domains but not mechanistically-related aminoacyl-tRNA synthetases. To improve the cell permeability of these inhibitors, we explore herein replacement of the α-amino group with an α-hydroxy group. In both macrocycles and corresponding linear congeners, this leads to decreased biochemical inhibition of the cysteine adenylation domain of the Yersina pestis siderophore synthetase HMWP2, which we attribute to loss of an electrostatic interaction with a conserved active-site aspartate. However, inhibitory activity can be regained by installing a cognate β-thiol moiety in the linear series. This provides a path forward to develop selective, cell-penetrant inhibitors of the biosynthesis of virulence factors to probe their biological functions and potential as therapeutic targets.