Separation of Phospholipids and Glycolipids Using Analytical Toroidal‐Coil Counter‐Current Chromatography. II. Comparison of the Hydrophobicity Between Mycoplasma fermentans and Human‐Brain Lipids

Abstract

Previously, we reported the successful separation of human‐brain lipids by toroidal‐coil countercurrent chromatography (TC‐CCC) avoiding emulsification and optimizing the solvent systems. In this study, the TC‐CCC technique was applied for the analysis of phosphocholine‐containing glycoglycerolipids (GGPL‐I and GGPL‐III) of Mycoplasma fermentans, which is thought to be one of the causative microorganisms of rheumatoid arthritis (RA). Neutral lipids of M. fermentans were separated and their elution profile compared with that of human‐brain lipids using a hexane:ethyl acetate:ethanol:0.1% TFA (5:5:5:4, v/v/v/v) solvent system. In this solvent system, the hydrophobicities of GGPL‐III and GGPL‐I were similar to those of lysophosphatidylcholine and sphingomyelin (SPM II), respectively. Glycoglycerolipid III was isolated, and further separated into at least two molecular species, using an optimized solvent system composed of hexane:ethyl acetate:ethanol:0.1% TFA (3:5:3:4, v/v/v/v). The TC‐CCC technique is a powerful tool for the separation of lipids of microorganisms, and more importantly, it may become a useful tool for the analysis of a host‐pathogen interaction or, in other words, a lipid–protein interaction at lipid microdomains.

Keywords:

• Counter‐current chromatography
• Phospholipid
• Glycolipids
• Lipid microdomain
• Mycoplasma fermentans