Synthesis and purification of structured triacylglycerols from evening primrose and viper's bugloss seed oils

Abstract

Structured triacylglycerols containing C18-PUFAs in sn-2 position and caprylic acid in sn-1,3 positions of the glycerol backbone (MLM-structure) have been synthesized and fractionated using evening primrose (Oenothera biennis) and viper's bugloss (Echium plantagineum) seed oils as starting materials. After enzymatic hydrolysis of triacylglycerol fractions from these natural oils, synthesis with Candida antarctica lipase was carried out by two different pathways and results were compared. After enzymatic synthesis and isolation of the whole triacylglycerol fraction from the reaction medium, several triacylglycerol fractions were obtained after chromatographic purification and further regiospecific analysis were performed. Some interesting fractions were found, being the most representative those containing linoleic or γ-linolenic acids as main component in sn-2 position from evening primrose seed oil, and stearidonic acid from viper's bugloss seed oil. All solvents used in enzymatic processes and purification methodologies were legally allowed for alimentary processing to make possible the use of the final products with alimentary or pharmaceutical purposes.