title: Identification and structural characterization of an unusual mycobacterial monomeromycolyl-diacylglycerol.
abstract: Systematic thin layer chromatographic (TLC) analysis of apolar lipids in Mycobacterium kansasii revealed the presence of a previously uncharacterized novel component. The product was ubiquitously found in a panel of M. kansasii clinical isolates, as well as other pathogenic and non-pathogenic mycobacterial species. TLC analysis of [(14)C]-acetate- or [(14)C]-glycerol-labelled M. kansasii cultures tentatively assigned the novel product as an unusual triacylglycerol-related lipid. Subsequent purification, followed by structural determination using (1)H-nuclear magnetic resonance (NMR) and electrospray mass spectrometry (ES/MS), led to the identification of this product as a monomeromycolyl-diacylglycerol (MMDAG). Treatment of M. kansasii with either isoniazid (INH), a well-known type II fatty acid synthase (FAS-II) and mycolic acid biosynthesis inhibitor, or tetrahydrolipstatin (THL), a drug approved for treating obesity, correlated with a reduced incorporation of [(14)C]-acetate into both mycolic acids and MMDAG. Addition of INH or THL to the cultures induced major morphological changes and, surprisingly, resulted in an increased number of lipid storage bodies, as determined by electron microscopy. The potent antimycobacterial activity of THL was confirmed against a variety of mycobacterial species, including INH-susceptible and -resistant Mycobacterium tuberculosis strains. Therefore, THL and other beta-lactones may be promising drugs for the development of new antitubercular therapy.
authors.affiliation: Laboratoire des Mécanismes Moléculaires de la Pathogénie Microbienne, INSERM U629, Institut Pasteur de Lille, 1, rue du Prof. Calmette, F-59019 Lille, France. laurent.kremer@univ-montp2.fr
authors.forename: Laurent
authors.initials: L
authors.lastname: Kremer
authors.forename: Chantal
authors.initials: C
authors.lastname: de Chastellier
authors.forename: Gary
authors.initials: G
authors.lastname: Dobson
authors.forename: Kevin J C
authors.initials: KJ
authors.lastname: Gibson
authors.forename: Pablo
authors.initials: P
authors.lastname: Bifani
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Balor
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Gorvel
authors.forename: Camille
authors.initials: C
authors.lastname: Locht
authors.forename: David E
authors.initials: DE
authors.lastname: Minnikin
authors.forename: Gurdyal S
authors.initials: GS
authors.lastname: Besra
mesh_terms: D019440:Anti-Obesity Agents / Q000494:pharmacology; D000995:Antitubercular Agents / Q000737:chemistry / Q000494:pharmacology*; D004075:Diglycerides / Q000096:biosynthesis* / Q000737:chemistry*; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000494:pharmacology; D064429:Fatty Acid Synthases / Q000037:antagonists & inhibitors; D007538:Isoniazid / Q000494:pharmacology; D007783:Lactones / Q000494:pharmacology; D008055:Lipids / Q000096:biosynthesis; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D019909:Mycobacterium kansasii / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D000077403:Orlistat; D021241:Spectrometry, Mass, Electrospray Ionization; D014280:Triglycerides / Q000096:biosynthesis* / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D019440:Anti-Obesity Agents; D000995:Antitubercular Agents; D004075:Diglycerides; D004791:Enzyme Inhibitors; D007783:Lactones; D008055:Lipids; D014280:Triglycerides; D000077403:Orlistat; D064429:Fatty Acid Synthases; D007538:Isoniazid