Abstract
The phosphoaminolipids obtained from cephalins of the muscle of a tuna, Thynnus orientalis, were converted to their dinitrophenyl (DNP) derivatives and applied to the chromatographic separation with a silicic acid/celite (2:1) column and chloroform/methanol to yield a DNP-ethanolamine-containing lipid (I), and amino acid-containing lipids (II), which gave a DNP-serine-containing lipid (II-a) and a mixture of DNP-serine-containing and DNP-threonine-containing lipids (II-b) by rechromatography. Hydrolysis of I with hydrochloric acid yielded DNP-ethanolamine, which gave free ethanolamine by decomposing with concentrated ammonium hydroxide. DNP-serine and-threonine, and free serine and threonine were isolated and identified with the same manner from II-a and II-b respectively. Periodate oxidation of the threonine fraction obtained from DNP-threonine of II-b gave acetaldehyde and glyoxylic acid. Component fatty acids of each fraction were found to be palmitic and oleic acids by paper chromatography. The presence of palmitoyloleoylglycerylphosphoryl esters of ethanolamine, serine and threonine can be supposed.
