Incorporation of fatty acids and the positional distribution analysis of fatty acids in acylglycerols of the insect Ceratitis capitata

Abstract

1.1. In vitro time-course of the labelled palmitic acid incorporation into larval triacylglycerols of Ceratitis capitata exhibited a tendency to reach the analytical values of the sn-distribution.2.2. However, in the fatty acid incorporation by pharate adult homogenates, palmitic acid showed a tendency to get the mass analytical contents but oleic acid did not.3.3. It suggests the incorporation of unsaturated fatty acids into the position sn-2 by synthetic routes different from the de novo pathway.4.4. Stereospecific distribution of the fatty acids was analysed in diacylglycerols and triacylglycerols from the different stages of development of the insect.5.5. Position sn-1 was mainly esterified by saturated fatty acids; unsaturated fatty acids, palmitoleic acid and oleic acid, linked at the sn-2 whereas in the position sn-3 there was a mixture of saturated and unsaturated fatty acids.6.6. Triacyglycerols from larvae, pharate adults and adults were highly asymmetrical whereas triacylglycerols from eggs were more symmetrical because of the higher presence of unsaturated fatty acids at the position sn-1.7.7. Distribution of fatty acids in diacyl-sn-glycerols and triacyl-sn-glycerols where rather similar; some discrepancies are interpreted as due to transacylation reactions in the de novo triacyl-sn-glycerols to reach their characteristic final distribution.