CHEMICAL CHARACTERIZATION OF THE ESTER-LINKED 3-HYDROXY FATTY ACYL-CONTAINING LIPIDS IN MYCOBACTERIUM-TUBERCULOSIS

In a previous study (S. Alugupalli, F. Portaels, and L. Larsson, J. Ba cteriol. 176:2962-2969, 1994), we reported the occurrence of 21 3-hydr oxy fatty acids (3-OH-FAs) in the methanolysis products of different m ycobacterial species. The present study was undertaken in order to che mically characterize the ester-linked complex native forms of these ac ids in Mycobacterium tuberculosis. Three 3-ON-FA-containing lipids wer e purified by chromatography and analyzed by one- and two-dimensional nuclear magnetic resonance spectroscopy, by fast atom bombardment-mass spectrometry, and by various conventional chemical analysis technique s, 3-OH-2,4,6-trimethyl-FAs were found in 2,3-diacyl trehalose and 2,3 ,6,6'-tetra-acyl-2'-sulfate trehalose (sulfatide I), two specific glyc olipids of the tubercle bacillus, explaining the specific occurrence o f these fatty acids in the methanolysis products of virulent strains o f M. tuberculosis. Straight-chain 3-OH-FAs were localized in phosphati dyl ethanolamine but not in the other phospholipids, suggesting a poss ible role of this class of phospholipids in the metabolism of fatty ac ids in actinomycetes.