Immunochemical studies of trehalose-containing major glycolipid from Tsukamurella pulmonis

The chemical structure of the major glycolipid present in the chloroform-methanol extract of bacterial biomass of Tsukamurella pulmonis is reported. This compound was purified by TLC and HPLC. The sugar analysis revealed only glucose. Detailed chemical analyses, NMR, and MALDI FT-ICR-mass spectrometric studies identified 2,3-di-O-acyl-alpha-d-glucopyranosyl-(1-->1)-alpha-d-glucopyranose as the final structure. Short branched fatty acids (4:0 or 5:0) were linked to C-3 and saturated, mono, and diunsaturated 18:0, 18:1, 18:2, 20:1, 20:2, and 20:0 to C-2 of the same glucose residue. ELISA tests revealed the weak cross-reactivity of the glycolipid with rabbit antisera against cells of T. paurometabola, Rhodococcus wratislaviensis, and Nocardiopsis dassonvillei.