Rugulactone and its analogues exert antibacterial effects through multiple mechanisms including inhibition of thiamine biosynthesis.
Rugulactone is a dihydro-α-pyrone isolated from the plant Cryptocarya rugulosa in 2009. It has been reported to display IkB kinase (IKK) inhibitory activity, as well as antibiotic activity in several strains of pathogenic bacteria. However, its biological targets and mode of action in bacteria have not yet been explored. Here we present enantioselective syntheses of rugulactone and of some corresponding activity-based protein profiling (ABPP) probes. We found that the ABPP probes in this study are more potent than rugulactone against Staphyloccocus aureus NCTC 8325, S. aureus Mu50, Listeria welshimeri SLCC 5334 and Listeria monocytogenes EGD-e, and that molecules of this class probably exert their antibacterial effect through a combination of targets. These targets include covalent inhibition of 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate (HMPP) kinase (ThiD), which is an essential component of the thiamine biosynthesis pathway in bacteria. This represents the first example of a small-molecule inhibitor of ThiD.
Department Chemie, Centre for Integrated Protein Science CIPSM, Institute of Advanced Studies, Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany.
Matthew B
MB
Nodwell
Helge
H
Menz
Stefan F
SF
Kirsch
Stephan A
SA
Sieber
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D001665:Binding Sites; D031369:Cryptocarya / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000187:drug effects; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D040901:Proteomics; D013211:Staphylococcus aureus / Q000187:drug effects; D013831:Thiamine / Q000096:biosynthesis*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D007783:Lactones; C548571:rugulactone; D013831:Thiamine