title: Synthesis and mass spectral characterization of mycobacterial phosphatidylinositol and its dimannosides.
abstract: A family of naturally occurring mycobacterial phosphatidylinositol (PI) and its dimannosides (PIM(2), AcPIM(2), and Ac(2)PIM(2)) that all possess the predominant natural 19:0/16:0 phosphatidyl acylation pattern were prepared to study their mass spectral fragmentations. Among these, the first synthesis of a fully lipidated PIM (i.e., (16:0,18:0)(19:0/16:0)-PIM(2)) was achieved from (±)-1,2:4,5-diisopropylidene-D-myo-inositol in 16 steps in 3% overall yield. A key feature of the strategy was extending the utility of the p-(3,4-dimethoxyphenyl)benzyl protecting group for its use at the O-3 position of inositol to allow installation of the stearoyl residue at a late stage in the synthesis. Mass spectral studies were performed on the synthetic PIMs and compared to those reported for natural PIMs identified from a lipid extract of M. bovis BCG. These analyses confirm that fragmentation patterns can be used to identify the structures of specific PIMs from the cell wall lipid extract.
authors: University of Otago, P.O. Box 56, Dunedin, New Zealand.
authors: Gregory M
authors: GM
authors: Rankin
authors: Benjamin J
authors: BJ
authors: Compton
authors: Karen A
authors: KA
authors: Johnston
authors: Colin M
authors: CM
authors: Hayman
authors: Gavin F
authors: GF
authors: Painter
authors: David S
authors: DS
authors: Larsen
mesh_terms: D002473:Cell Wall / Q000737:chemistry; D007294:Inositol / Q000031:analogs & derivatives*; D009682:Magnetic Resonance Spectroscopy; D008362:Mannosides / Q000138:chemical synthesis*; D008970:Molecular Weight; D009163:Mycobacterium bovis / Q000737:chemistry*; D010716:Phosphatidylinositols / Q000138:chemical synthesis*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D008362:Mannosides; D010716:Phosphatidylinositols; D007294:Inositol