The phospholipids of ox spleen with special reference to the fatty acid and fatty aldehyde compositions of the lecithin and kephalin fractions

Abstract

Phospholipids equivalent to about 600 mg P/kg fresh tissue were extracted from ox spleen with chloro-form-methanol mixtures and were fractionated on silicic acid columns. The percentage composition of the phospholipid was: cardiolipin, 3; phosphatidylethanolamine, 9; phosphatidylserine, 14; ethanolamine plasmalogen, 10; serine plasmalogen, 5; phosphatidylcholine, 35; choline plasmalogen, 4; sphingomyelin, 10; unidentified, 4; not recovered, 6. The fatty acids of the ester phosphatides and the fatty acids and aldehydes of the corresponding plasmalogens were isolated after treatment of the mixed phosphatide fractions with 90% acetic acid at 38[degree] and separation of the products on silicic acid. The composition of the various fatty acid and fatty aldehyde mixtures from the phosphatide fractions of ox spleen were determined by gas-liquid chromatography and the distribution patterns were compared with those of similar fractions from ox heart, ox liver, pig heart and ram semen. Large amounts (approximately 50% of branched-chain aldehydes are present in ox-spleen choline plasmalogen and ox-liver plasmalogens. A branched-chain C15 compound is a major component of the aldehydes from both these tissues. The results suggest a selective incorporation of saturated fatty acids and aldehydes of 16 carbon atoms into lecithin and choline plasmalogen and of 18 carbon atoms into kephalin and kephalin plasmalogen.