Mycolipenates and Mycolipanolates of Trehalose from Mycobacterium tuberculosis

Abstract

Analysis of the lipids of Mycobacterium tuberculosis, by thin-layer chromatography, revealed the presence of two families of novel glycolipids each having two closely-related members but differing widely in polarity. The least and most polar families of lipids were characterized from M. tuberculosis strains C and H37Rv, respectively; all were based on trehalose, the least polar pair of glycolipids having more long-chain substituents than the more polar pair. The acyl substituents of the least polar of the four glycolipids were mainly straight-chain C₁₆ and C₁₈ acids and 2,4,6-trimethyltetracos-2-enoic (C₂₇-mycolipenic) acid, and the second least polar glycolipid contained major amounts of 3-hydroxy-2,4,6-trimethyltetracosanoic (C₂₇-mycolipanolic) acid in addition to these non-hydroxylated acids. The relatively polar pair of glycolipids were analysed together and released mainly straight-chain C₁₆ and C₁₈ acids, C₂₇-mycolipanolic acid, minor amounts of C₂₅-and C₂₇-mycolipenic acids and major proportions of an acid having the chromatographic properties of 2,4-dimethyldocosanoic acid. The most polar pair of glycolipids co-chromatographed with glycolipid antigens previously detected in Mycobacterium bovis BCG.