Obtention of highly purified fractions of eicosapentaenoic acid and docosahexaenoic acid from sardine oil by silver-resin chromatography: A semi-preparative procedure

Abstract

Pure fractions of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were obtained from silver-resin column chromatography of EPA+DHA concentrates obtained from sardine oil. Two types of silver-impregnated resins were assayed; Amberlite IR-118H and Dowex 50 W-HCR-W2. The Amberlite-silver column allows the separation of almost pure fractions (98.5%) of EPA, being unable to separate DHA from other polyunsaturated fatty acids. The Dowex-silver column does not separate the EFA from the concentrate but allows the isolation of a highly purified fraction of DHA. The chromatographic procedure described may provide pure forms of two important n-3 polyunsaturated fatty acids for nutritional or pharmacological research or as substrates for the obtention of structured lipids.