Food Chemical Studies on Soybean Phospholipids

Part VIII. Molecular species of 3-sn-phosphatidylcholine

Abstract

The molecular species of 3-sn-phosphatidylcholine from soybean were determined after convertion into diglyceride acetates by means of hydrolysis with phospholipase C and acetylation with acetic anhydride and pyridine. The resultant diglyceride acetates were separated by thin layer and columnchromatography on silica impregnated with silver nitrate into 7 (LDGA-1-7) and 13 (LDGAA-L) differing with respect to their degree of unsaturation, respectively. Furthermore, the diglyceride acetates were separated by gas liquid chromatography on 3% -JXR on the basis of total carbon number of the fatty acids.
As the results, the amount of the 3-sn-phosphatidylcholine composed of total carbon number 36(16+20, 18+18), 34(18+16, 14+20) and 38(20+18) was abundant, and this accorded with the large amount of linolenic acid (59.4%) and palmitic acid (10.6%) in the original 3-sn-phosphatidylcholine. Notwithstanding the original 3-sn-phosphatidylcholine contained arachidonic, eicosatrienoic and eicosadienoic acid in comparatively large quantities, the amount of the 3-sn-phosphatidylcholine composed of total carbon number 40 was scarcely, and this showed that the combination of the fatty acids' carbon number among both ester positions in the 3-sn-phosphatidylcholine were not (20+20), but (12+20), (14+20), (16+20) or (18+20).