engleski

Application of Chromatography Methods for Analysis of Fatty Acid Composition and Stereochemical Distribution in Phospholipids

Phospholipids are well known as major constitutive elements of cell membranes, but there is an increasing interest in their role in membrane signaling. In order to obtain new informations on structural features of phospholipids isolated from different tissues, we have used some chromatographic methods. The aim of the study was to determine the stereospecific distribution of fatty acids on sn-1 and sn-2 position on glycerophospholipid molecules. Total lipids were extracted from rats' tissues and phospholipids were separated by column and thin layer chromatography. Fatty acids from sn-2 position were hydrolyzed by the action of phospholipase A2 from Crotalus adamanteus venom, while sn-1 linked fatty acids were liberated by methanolysis. Fatty acid methyl esters were analyzed by gas-liquid chromatography (GC). Evaluation of chromatograms revealed some unexpected results, with relatively high peak at Rt nearly identical to Rt for linolenic acid. In order to check the identity of this component, samples were additionally analyzed by coupled GC-Mass Spectrometry method. The results have shown the presence of a strange substance which was neither linolenic acid, nor fatty acid or its derivative at all, but which could not be separated from other fatty acid methyl esters by means of usual separation methods.

gas chromatography; phospholipid; fatty acid

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