SYNTHESIS OF METHYL (Z)-TETRACOS-5-ENOATE AND BOTH ENANTIOMERS OF ETHYL (E)-6-METHYLTETRACOS-4-ENOATE - POSSIBLE INTERMEDIATES IN THE BIOSYNTHESIS OF MYCOLIC ACIDS IN MYCOBACTERIA

The high molecular weight 2-alkyl-3-hydroxy mycolic acids are key structural components of the cell envelope of pathogenic mycobacteria, such as Mycobacterium tuberculosis. A prime target for drug action would be the initial stages where the biosynthetic pathways diverge from those of ordinary fatty acids. It has been postulated that the pathway for the alpha-mycolates, without oxygen functions in addition to the hydroxy-acid unit, appears to diverge from (Z)-tetracos-5-enoic acid. The biosynthesis of oxygenated mycolic acids is considered to possibly diverge from (E)-6-(R)-methyltetracos-4-enoic and (E)-6-(S)-methyltetracos-4-enoic acids. This communication describes the synthesis of esters of these acids in order to test their potential role in the biosynthesis of mycolic acids.