title: Structure elucidation and chemical synthesis of stigmolone, a novel type of prokaryotic pheromone.
abstract: Approximately 2 micromol of a novel prokaryotic pheromone, involved in starvation-induced aggregation and formation of fruiting bodies by the myxobacterium Stigmatella aurantiaca, were isolated by a large-scale elution procedure. The pheromone was purified by HPLC, and high-resolution MS, IR, 1H-NMR, and 13C-NMR were used to identify the active substance as the hydroxy ketone 2,5, 8-trimethyl-8-hydroxy-nonan-4-one, which has been named stigmolone. The analysis was complicated by a solvent-dependent equilibrium between stigmolone and the cyclic enol-ether 3,4-dihydro-2,2, 5-trimethyl-6-(2-methylpropyl)-2H-pyran formed by intramolecular nucleophilic attack of the 8-OH group at the ketone C4 followed by loss of H2O. Both compounds were synthesized chemically, and their structures were confirmed by NMR analysis. Natural and synthetic stigmolone have the same biological activity at ca. 1 nM concentration.
authors.affiliation: Central Spectroscopy Department, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany. wplaga@sun0.urz.uni-heidelberg.de
authors.forename: W E
authors.initials: WE
authors.lastname: Hull
authors.forename: A
authors.initials: A
authors.lastname: Berkessel
authors.forename: W
authors.initials: W
authors.lastname: Plaga
mesh_terms: D000473:Alkanes / Q000138:chemical synthesis / Q000737:chemistry; D002449:Cell Aggregation / Q000187:drug effects / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D009231:Myxococcales / Q000737:chemistry*; D010675:Pheromones / Q000138:chemical synthesis / Q000737:chemistry*; D011387:Prokaryotic Cells / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000473:Alkanes; D007659:Ketones; D010675:Pheromones