Separation of natural polyunsaturated fatty acids by means of lodolactonization

Conditions of the iodolactonization reaction (ILreaction) were optimized as a method for separation of natural polyunsaturated fatty acids. The effects of the solvent, temperature and the ratio of components of the iodizing complex KI/I₂ upon the rate of the synthesis of several iodolactones (ILs) in the IL-reaction are described. It was shown that the rate of formation of γ-ILs was significantly higher than that for δ-ILs. This offers opportunity for obtaining pure docosahexaenoic acid (DHA) from fatty acid (FA) concentrates. The possibility for selective reduction of δ-ILs in the presence of γ-ILs to yield pure arachidonic acid (AA) or eicosapentaenoic acid (EPA) or fatty acid concentrates has been demonstrated. Preparation of pure AA from a mixture of AA, DHA and other FAs by the IL-reaction without Chromatographie procedures is described.