Chemical and spectroscopic characterisation of the phosphatidylinositol manno-oligosaccharides from Mycobacterium bovis AN5 and WAg201 and Mycobacterium smegmatis mc2 155

Two classes of phosphatidylinositol manno-oligosaccharides (PIMs) were isolated from each of Mycobacterium bovis AN5 and WAg201 and Mycobacterium smegmatis mc2 155. The deacylated PIMs (dPIMs), were identified as hexasaccharide (dPIM-6) and disaccharide (dPIM-2) species composed of mannose, myo-inositol, glycerol and phosphate residues in the proportions of 6:1:1:1 and 2:1:1:1, respectively. Structural analysis, employing a combination of microanalytical methods, nuclear magnetic resonance spectroscopy, and mass spectrometric techniques established that the sequence of residues within dPIM-6, as shown below, was identical in the three mycobacterial strains investigated.