A modified loop for sample application in thin-layer chromatography.

We described previously the unusual structures of the two major C-mycoside glycopeptidolipids from Mycobacterium fortuitum biovar. peregrinum. More polar glycolipids, potentially more interesting in terms of antigenicity, were also present in the strains. A combination of FAB mass spectrometry, NMR, chemical analyses, and radiolabeling was successfully applied to these glycolipids to arrive at the unexpected and novel structure for the more polar compound. This consisted of the "orthodox" basic structure of the apolar C-mycosides, modified at the alaninol end by the presence of a sulfate group on position 2 of a 3,4-di-O-methylrhamnosyl residue. This novel and second class of sulfate-containing mycobacterial glycolipid may provide a chemical basis for the differentiation and classification of members of the M. fortuitum complex, the main group causing human diseases among the many fast-growing mycobacteria widely distributed in nature.

Chromatography, Thin Layer↗

PubMed1992

A new glycolipid from Mycobacterium avium--Mycobacterium intracellulare complex.

From a nonpolar lipid fraction of Mycobacterium avium--Mycobacterium intracellulare complex cell mass, a new glycolipid was obtained, which was shown to be 5-mycoloyl-beta-arabinofuranosyl-(1-->2)-5-mycoloyl-alpha-ar abinofuranosyl- (1-->1')-glycerol. When examined by TLC, all the 12 strains of this species tested, including clinical isolates, were found to contain this glycolipid. But the glycolipid was not detected in Mycobacterium bovis BCG or Mycobacterium tubrculosis H37Rv.

Chromatography, Thin Layer↗

PubMed1992

Thin-layer chromatography-flame ionization detection Iatroscan system.

The thin-layer chromatography-flame ionization detection (TLC-FID) Iatroscan system is a technique which is still being evolved. Quantification with the TLC-FID system relies heavily on the accurate setting up and calibration of the instrument. An appreciation of the factors that influence the analysis can eliminate significant errors. At least a few of the numerous operating variables need to be fixed to obtain coherent results from different laboratories. Hydrogenation of the sample is recommended in order to improve quantification with the Iatroscan system. The improved reproducibility obtained with automatic sample spotters compared with manual spotting indicates that autosampling is highly advisable.

Chromatography, Thin Layer↗