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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Bioproducts Research » Research » Publications at this Location » Publication #305904
Title: Quantification of the molecular species of diacylglycerols,triacylglycerols and tetraacylglycerols in lesquerella (Physaria fendleri) oil by HPLC and MS

Author
item Lin, Jiann

Submitted to: International Symposium on Biocatalysis and Biotechnology: Functional Food and Industrial Products
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2014
Publication Date: 10/28/2014
Citation: Lin, J.T. 2014. Quantification of the molecular species of diacylglycerols,triacylglycerols and tetraacylglycerols in lesquerella (Physaria fendleri) oil by HPLC and MS. International Symposium on Biocatalysis and Biotechnology: Functional Food and Industrial Products. October 28-31, 2014, Kaoshiung, Taiwan /page 74.

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. Lesquerolate, a homolog of ricinoleate, in lesquerella oil can be used for 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. We reported recently the identification of 74 molecular species of triacylglycerols, ten molecular species of diacylglycerols and 13 molecular species of tetraacylglycerols in lesquerella oil. We report here the quantification of these acylglycerols using a new method with high-performance liquid chromatography and mass spectrometry.

Technical Abstract: Ten diacylglycerols (DAG), 74 triacylglycerols (TAG) and 13 tetraacylglycerols in the seed oil of Physaria fendleri were recently identified by HPLC and MS. These acylglycerols (AG) were quantified by HPLC with evaporative light scattering detector and electrospray ionization mass spectrometry of the lithium adducts of the AG in the HPLC fractions of lesquerella oil (new method). The HPLC peak area % represented the content of AG in that HPLC peak. The MS1 ion signal intensities of molecular ions [M + Li]+ in HPLC fractions of a HPLC peak were used to estimate the ratios of the molecular species of AG in the HPLC peak. The ratios of AG with the same mass in HPLC fractions were estimated by the ratios of the sums of MS2 ion signal intensities of fragment ions mainly from the neutral loss of fatty acids [M + Li - FA]+. The content of ten DAG combined was about 1%, 74 TAG was about 98% and 13 tetraacylglycerols was about 1%. The contents of DAG in decreasing order were: LsLs (0.25%), LsLn (0.25%), LsO (0.24%), LsL (0.11%) and the contents of TAG in decreasing order were: LsLsO (31.3%), LsLsLn (24.9%), LsLsL (15.8%), LsL-OH20:2 (4.3%), LsO-OH20:2 (2.8%), and LsLn-OH20:2 (2.5%). The highest contents of the molecular species of tetraacylglycerols were from those containing one normal FA (non-hydroxylated) and they were LsLsLsO (0.25%), LsLsLsL (0.24%), LsLsLsLn (0.21%) and LsLs-OH20:2-O (0.19%).