Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2008
Publication Date: 6/13/2008
Citation: Lin, J.T., Arcinas, A.J. 2008. Analysis of regiospecific triacylglycerols by electrospray ionization-mass spectrometry 3 of lithiated adducts. Journal of Agricultural and Food Chemistry. 56:4909-4915. Interpretive Summary: Castor oil contains high level of ricinoleate (hydroxyl fatty acid) for industrial uses. However castor also contains toxic substances. It is desirable to produce high level of ricinoleate in other oil seed plants. It is important to know the biosynthetic pathway of castor oil to develop other plants to produce ricinoleate. Identification of regiospecific location of fatty acids on the molecule species of castor oil will identify enzymatic step incorporating non-hydroxyl fatty acids. The inhibition of this enzymatic step might be used to increase ricinoleate content in seed oil. This paper describes the method to identify and quantify the regioisomers of triacylglycerols.
Technical Abstract: Some regiospecific triacylglycerol standards containing normal fatty acids, e.g., 1,3-dioleoyl-2-palmitoyl-glycerol (OPO) and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP), were analyzed by the electrospray ionization MS3 of their lithiated adducts. The fragment ions of the MS3 from the loss of alpha, beta-unsaturated fatty acids at the sn-2 position can be used for the identification and quantification. The ratio of regiospecific triacylglycerols, ABA and AAB, in a sample usually fraction collected by HPLC can be determined by the ratio of the abundances of the fragment ions of [ABA + Li – ACOOH – B'CH=CHCOOH]+ and [AAB + Li – ACOOH – A'CH=CHCOOH]+.