Synthesis of reversed structured triacylglycerols possessing EPA and DHA at their terminal positions

This report describes synthesis of reversed structured triacylglycerols (TAGs) of the LML type, possessing pure EPA or DHA located at the terminal 1,3-positions of the glycerol backbone along with pure even number saturated fatty acids (C6:0-C16:0) occupying the 2-position. These compounds were synthesized by a two-step chemoenzymatic route involving a highly regioselective immobilized Candida antarctica lipase to incorporate EPA or DHA activated as acetoxime esters exclusively into the 1,3-positions of glycerol. The saturated fatty acyl groups were subsequently introduced to the remaining 2-position by EDCI coupling agent to accomplish the title compounds highly efficiently. This is the first report on reversed structured TAGs possessing the long-chain n-3 polyunsaturated fatty acids. It is anticipated that these novel compounds and their synthetic methodology will find various important uses such as analytical standards, in screening for bioactivity and in the pharmaceutical area as prodrugs. (C) 2015 Elsevier Ltd. All rights reserved.