The mycolipanolic acids

Abstract

A series of homologous hydroxy-acids, now named mycolipanolic acids, has been isolated from the lipids of human tubercle bacilli. N.m.r. and mass spectrometric studies of the corresponding methyl esters and their anhydro- and acetyl derivatives are described, and evidence is presented that the above acids have the structure Me·[CH₂]_n·CHMe·CH₂·CHMe·CH(OH)·CHMe·CO₂H where n for the main homologue is 17, and for the minor homologues 19, 18, 16, and 15, respectively, and C-4 and C-6 have the L-configuration. High-resolution i.r. studies of the methyl esters and their epimers are also reported, and the natural products are shown to have the erythro-configuration with respect to C-2 and -3.