Identification of n-6 Monounsaturated Fatty Acids in Acer Seed Oils

Abstract

Seed oils fromAcerspecies are a potential sourceof the nutraceutical fatty acids, nervonic acid (cis-15-tetracosenoic acid, NA), andγ-linolenic acid (cis-6,9,12-octadecatrienoic acid, GLA). To further characterize thegenus, seed fatty acid content and composition were deter-mined for 20 species ofAcer.Fatty acid content ranged from8.2% forAcer macrophyllumto over 36% forA. monoandA.negundo. The presence of very-long-chain fatty acids(VLCFA), with chain length of 20-carbons or greater, andGLA were characteristic features of the seed oils. In allspecies, erucic acid (cis-13-docosenoic acid, EA) was the pre-dominant VLCFA with the highest level of NA being only8.6% inA. olivianum.Regioselective lipase digestion demon-strated that VLCFA are largely absent from thesn-2 positionof seed triacylglycerol, whereas GLA is primarily located atthis position. FiveAcerspecies contained low levels (<2%)ofcis-12-octadecenoic acid andcis-14-eicosenoic acid,uncommonn-6 fatty acids not previously reported fromAcer.