OBTENTION OF HIGHLY PURIFIED FRACTIONS OF EICOSAPENTAENOIC ACID AND DOCOSAHEXAENOIC ACID FROM SARDINE OIL BY SILVER-RESIN CHROMATOGRAPHY - A SEMIPREPARATIVE PROCEDURE

Pure fractions of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were obtained from silver-resin column chromatography of EPA+DH A concentrates obtained from sardine oil. Two types of silver-impregna ted 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 polyunsaturat ed fatty acids. The Dowex-silver column does not separate the EPA from the concentrate but allows the isolation of a highly purified fractio n of DHA. The chromatographic procedure described may provide pure for ms of two important n-3 polyunsaturated fatty acids for nutritional or pharmacological research or as substrates for the obtention of struct ured lipids.