A Triacyltrehalose Containing 2-Methyl-Branched Unsaturated Fatty Acyl Groups Isolated from Mycobacterium Fortuitum

Summary: A variety of glycolipids were found in a collection of strains of Mycobacterium fortuitum and two patterns were established by thin-layer chromatography. A compound present in all the strains studied was identified as 2,3,4-triacyltrehalose and its overall structure determined by infrared spectroscopy, nuclear magnetic resonance spectroscopy and gas-liquid chromatography–mass spectrometry. Fatty acyl groups present in this molecule were identified as tetradecanoyl, hexadecenoyl, hexadecanoyl, octadecenoyl, octadecanoyl and a variety of 2-methyl-branched unsaturated (α-methyl, α,β-unsaturated) acyl groups. The 2-methyl-branched compounds ranged from 17 to 21 carbon atoms, the most abundant being 2-methyloctadecen-2-oyl. Trehalose was the only sugar detected in the glycolipid. This substance immunoreacted with IgG and IgM present in sera from tuberculosis patients, as demonstrated by an enzyme-linked immunosorbent assay.