Preparation of radiolabled tetracosa mono- and dienoic acid methyl esters from rat erythrocyte lipids by thin layer chromatography.

An easy method of obtaining pure fatty acid methyl esters (FAME) of tetracosa mono- and dienoic acids (24:1, 24:2) using thin layer chromatography (TLC) is described. The total lipids isolated from rat erythrocytes were treated with methanolic-NaOH. Sphingomyelin was unaffected by this treatment and was separated from FAME of glycerolipids and cholesterol by TLC. FAME of sphingomyelin were then prepared by acid methanolysis. These esters migrated into 2 distinct bands on TLC. The slow moving band contained FAME of 16:0, 16:1, 18:0, 18:1, 19:0 and 20:0 wheras the fast moving band contained FAME of 22:0, 23:0, 24:0, 24:1 and 24:2. After AgNO3-TLC, the FAME of the fast moving band separated into 3 species; esters of saturated acids, 24:1 and 24:2, respectively. With erythrocyte lipids of rats fed a fat-free diet and injected with 14C-18:1, this method yielded 14C-24:1. From rats injected with 14C-18:2 and maintained on a corn oil diet, 14C-24:2 was obtained.