title: Positional distribution of FA in TAG of enzymatically modified borage and evening primrose oils.
abstract: Stereospecific analysis was carried out to establish positional distribution of FA in the TAG of DHA, EPA, and (EPA + DHA)-enriched oils. In this study, TAG of enzymatically modified oils were purified using a silicic acid column. The TAG were then subjected to positional distribution analysis using a modified procedure involving reductive cleavage with Grignard reagent. The results showed that in DHA-enriched borage oil (BO), DHA was randomly distributed over the three positions of TAG, whereas gamma-linolenic acid (GLA) was mainly esterified at the sn-2 and -3 positions. In DHA-enriched evening primrose oil (EPO), however, DHA and GLA were concentrated in the sn-2 position. In EPA-enriched BO, EPA was randomly distributed over the three positions of TAG, similar to that observed for DHA. In EPA-enriched EPO, however, this FA was mainly located at the primary positions (sn-1 and sn-3) of TAG. In both oils, GLA was preferentially esterified at the sn-2 position. In (EPA + DHA)-enriched BO, EPA and DHA were mainly esterified at the sn-1 and -3 positions of TAG, whereas GLA was mainly located at the sn-2 position. In (EPA + DHA)-enriched EPO, GLA was mainly located at the sn-2 and -3 positions; EPA was preferentially esterified at the sn-1 and -3 positions, and DHA was found mainly at the sn-3 position.
authors.affiliation: Department of Biochemistry, Memorial University of Newfoundland, St. John's, Canada.
authors.forename: S P J Namal
authors.initials: SP
authors.lastname: Senanayake
authors.forename: Fereidoon
authors.initials: F
authors.lastname: Shahidi
mesh_terms: D002175:Candida / Q000201:enzymology; D004281:Docosahexaenoic Acids / Q000032:analysis / Q000737:chemistry; D015118:Eicosapentaenoic Acid / Q000032:analysis / Q000737:chemistry; D004951:Esterification; D005227:Fatty Acids / Q000032:analysis*; D005228:Fatty Acids, Essential / Q000032:analysis / Q000737:chemistry*; D008041:Linoleic Acids; D008049:Lipase / Q000737:chemistry / Q000378:metabolism; D031665:Oenothera biennis; D010741:Phospholipases A / Q000737:chemistry / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism; D010938:Plant Oils / Q000032:analysis / Q000737:chemistry*; D011549:Pseudomonas / Q000201:enzymology; D013237:Stereoisomerism; D014280:Triglycerides / Q000032:analysis / Q000737:chemistry*; D017965:gamma-Linolenic Acid / Q000737:chemistry
chemical_list: D005227:Fatty Acids; D005228:Fatty Acids, Essential; D008041:Linoleic Acids; D010743:Phospholipids; D010938:Plant Oils; D014280:Triglycerides; D004281:Docosahexaenoic Acids; C028498:evening primrose oil; D017965:gamma-Linolenic Acid; D015118:Eicosapentaenoic Acid; D008049:Lipase; D010741:Phospholipases A; C079363:borage oil