Submitted to: Enliven: Bio Analytical Techniques
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2014
Publication Date: 10/1/2014
Citation: Lin, J.T., Chen, G.Q. 2014. Quantification of the molecular species of tetraacylglycerols in lesquerella (Physaria fendleri) Oil by HPLC and MS. Enliven: Bio Analytical Techniques. 1(1):1-5.
Interpretive Summary: Ricinoleate, a hydroxy fatty acid in castor oil, has many industrial uses such as the manufacture of biodegradable and renewable plastics, plasticizers, lubricants, cosmetics, paints and surfactants. Castor is the only commercial source of ricinoleate. Lesquerolate, a hydroxy fatty acid in lesquerella oil, can also be used in industry similar to those of ricinoleate. Lesquerella is a new industrial oilseed crop in the southwestern region of the U. S. valued for its lesquerolate. Lesquerolate is mostly (98%) in the form of triacylglycerols in lesquerella oil. Tetraacylglycerol contains an acyl (fatty acid) chain attached to the hydroxyl group of another acyl chain attached to the glycerol backbone. Tetraacylglycerols have different physical properties from those of triacylglycerols and can be used in industry similar to those of triacylglycerols for different physical properties such as viscosity and pour point improvers for lubricants. The molecular species of tetraacylglycerols in lesquerella oil have been identified recently. We report here the quantification of the thirteen molecular species of tetraacylglycerols in lesquerella oil. The contents were low and can be increased in the future for industrial uses.
Technical Abstract: Thirteen molecular species of tetraacylglycerols in the seed oil of Physaria fendleri were recently identified. We report here the quantification of these tetraacylglycerols using HPLC with evaporative light scattering detector and the MS of the HPLC fractions. Ion signal intensities of MS1 from the molecular species of AG with different m/z in a HPLC fraction were used to estimate the ratios of the molecular species. The ratios of the molecular species of AG with the same mass were estimated by the total ion signal intensities of the fragment ions of MS2, [M + Li - FA]+ and [M + Li - FA-FA]+. The content of tetraacylglycerols was about 1%. The highest contents of the molecular species of tetraacylglycerols were from those containing one normal FA and they were LsLsLsO (0.25%), LsLsLsL (0.24%), LsLsLsLn (0.21%) and LsLs-OH20:2-O (0.19%). The contents of the tetraacylglycerols containing two normal FA were lower than those containing one normal FA. Among them the highest were LsLsOL (0.10%), LsLsOO (0.06%) and LsLsOLn (0.06%).