Studies on the Lipids of Japanese Littleneck, Tapes japonica Deshayes. II.

Composition of Phospholipids

Abstract

The composition of the acetone-insoluble lipids obtained from Japanese Littleneck, Tapes japonica (Deshayes) was studied. The acetone-insoluble lipids were mostly composed of phospholipids.
Procedures used for the analysis of the constituents of phospholipids were as follows; silicic acid column chromatography of intact lipids, and paper chromatography of the water-soluble hydrolysis products of phospholipids according to Dawson, were found to be unsatisfactory. Thin-layer chromatography was not able to separate plasmalogens from analogous diacylphospholipids. Two-dimentional thin-layer chromatography according to Owens, which based on the specific hydrolysis of plasmalogens to lysophospholipids in the presence of mercuric chloride spray reagent was effective for the analysis of plasmalogens. By means of this method, phospholipids were separated into individual phospholipid, and lipid phosphorus was determined.
The results of the analysis were as follows; phospholipids were rich in ethanolamine phospho-lipids, and these were 23.1% phosphatidyl ethanolamine, 9.2% phosphatidal ethanolamine (ethanolamine plasmalogen), and 17.8% sphingo-ethanolamine. Other phospholipids determined were 19.8% phosphatidyl choline, 10.8% phosphatidyl serine, and 6.0% phosphatidyl inositol.