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United States Department of Agriculture

Agricultural Research Service

Title: Identification and Quantification of the Molecular Species of Triacylglycerols in Castor Oil by Lc-Esi-Ms

Authors
item Lin, Jiann-Tsyh
item Arcinas, Arthur

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 2005
Publication Date: September 25, 2005
Citation: Lin, J.T., Arcinas, A.J. 2005. Identification and quantification of the molecular species of triacylglycerols in castor oil by lc-esi-ms. Meeting Abstract.

Interpretive Summary: Ricinoleate (R, a hydroxy fatty acid) has many industrial applications in the manufacture of aviation lubricant, plastics, paints, coatings, cosmetics and others. Fatty acids (FA) occur as acylglycerols (AG) in castor oil, of which 90% of the FA is ricinoleate. Castor oil is currently the only commercial source of ricinoleate. Identification and quantification of the molecular species of AG in castor oil will help to understand the control mechanism to produce ricinoleate-containing AG (castor oil), as well as to help the industrial applications of castor oil. Castor bean contains toxic substances, and it is desirable to produce castor oil substitute in an oilseed of a transgenic plant lacking these toxic components. Many molecular species of AG have been identified and quantified by LC-ESI-MS (liquid chromatography - electrospray ionization - mass spectrometry).

Technical Abstract: Ricinoleate (R, a hydroxy fatty acid) has many industrial applications in the manufacture of aviation lubricant, plastics, paints, coatings, cosmetics and others. Fatty acids (FA) occur as acylglycerols (AG) in castor oil, of which 90% of the FA is ricinoleate. Castor oil is currently the only commercial source of ricinoleate. Identification and quantification of the molecular species of triacylglycerols (TAG) in castor oil will help to understand the control mechanism to produce ricinoleate-containing TAG (castor oil), as well as to help the industrial applications of castor oil. An ammonium acetate electrolyte solution (100 mM) was introduced into the HPLC effluent to produce ammonium adduct AG ions at 4.6 kilovolts using electrospray ionization (ESI) with an LCQ Advantage Ion-Trap mass spectrometry (Thermo-Finnigan). Eighteen molecular species of AG were previously identified by HPLC in castor oil, e.g., triricinoleoylglycerol (RRR, 71%), RRO (7.2%), RRL (6.6%), RRP (1.6%), RRS (1.1%), RR-lesqueroleate (0.67%), RRLn (0.15%) and diricinoleoylglycerol (RR, 0.14%). These AG were confirmed by LC-ESI-MS. RR-dihydroxystearate and RR-dihydroxyoleate were identified by LC-ESI-MS as minor constituents. Ricinoleoyl-triricinoleoylglycerol (RRRR), a new lipid subclass of AG containing four acyl chains, was also identified (0.47%). The fourth R of RRRR is attached to the hydroxyl group of a ricinoleoyl chain bonded to glycerol.

Last Modified: 11/23/2014
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