Positional distribution of n-3 highly unsaturated fatty acids in triacyl-sn-glycerols (TAG) of rotifers (Brachionus plicatilis) enriched with fish and seal oils TAG

This paper reports the positional distribution of fatty acids in triacyl-sn-glycerols (TAG) of rotifers Brachionus plicatilis enriched with marine oils TAG. The rotifers were enriched with fish and seal oils TAG for 4-24 h, and TAG isolated from the enriched rotifers were subjected to stereospecific analysis in order to determine the content of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in the sn-1, sn-2 and sn-3 positions of the TAG. In rotifers enriched with fish oil TAG, DHA was esterified in the three positions of TAG with the distribution patterns of sn-2 (highest)>sn-3>sn-1 (lowest) positions (4- and 8-h enrichments), sn-2 approximate to sn-3>sn-1 positions (12- and 18-h enrichments) and sn-3>sn-2>sn-1 positions (24-h enrichment). In rotifers enriched with seal oil TAG, DHA showed a consistent pattern of sn-3>sn-1>sn-2 positions (4-24 h). EPA in the 24-h enriched rotifers showed the patterns of sn-3>sn-2 approximate to sn-1 positions (fish oil TAG enrichment) and sn-3>sn-1>sn-2 positions (seal oil TAG enrichment). In the seal oil TAG enrichment, distribution patterns of DHA and EPA were similar between the dietary TAG and rotifers TAG. In contrast, distribution patterns of these fatty acids in the fish oil TAG (sn-2>sn-3>sn-1 positions) were not entirely held in the enriched rotifers. (C) 2004 Elsevier Science B.V. All rights reserved.