Isolation and characterization of the monounsaturated long chain fatty acids of Mycobacterium tuberculosis

The positions of double bond in the monounsaturated C15-C32 fatty acids of Mycobacterium tuberculosis H37Ra were established by gas chromatography/mass spectrometry of the ozonized esters and their pyrrolidide derivatives. The monounsaturated C15-C21 fatty acids had the double bond primarily at the delta 9 position while the monounsaturated longer chain fatty acids (C22-C32) had the double bond in several positions. Many of the latter acids, especially the odd-numbered series, were very complex isomeric mixtures. Quantitation showed the most abundant even-numbered long chain fatty acid isomers to be as follows: C22, delta 4; C24, delta 5; C26, delta 7 and delta 9; C28, delta 9; C30, delta 11 and delta 13; C32, delta 13 and delta 15.