CHROMATOGRAPHIC CHARACTERIZATION OF INTERNAL POLAR LIPIDS FROM WOOL

Wool internal polar lipids were isolated and separated into different fractions based on polarity. Qualitative and quantitative analyses of the different fractions were performed by thin-layer chromatography an d thin-layer chromatography coupled to flame-ionization detection, res pectively. Cholesterol esters, free fatty acids, sterols, ceramides, g lycosylceramides, and cholesterol sulfate were the main components, wi th ceramides being in the highest proportion. The fatty acid compositi on of ceramides and glycosylceramides was determined by gas chromatogr aphy/mass spectrometry. As for other keratinized tissues, long-chain f atty acids predominated in comparison to either free fatty acids or ph ospholipid-linked fatty acids; in both cases, stearic and lignoceric a cids were the most abundant fatty acids, and a low amount of 18-methyl eicosanoic acid was found. This work opens new avenues in the study of lipid rearrangement in more complex and realistic vesicle structures than conventional liposomes.