Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/10/2009
Publication Date: 5/3/2009
Citation: Lin, J.T. 2009. Analysis of acylglycerols containing mono- and dihydroxy fatty acids in castor oil by HPLC and MS. Award Lecture, 100th American Oil Chemists' Society Annual Meeting and Expo, May 3-6, 2009, Orlando, FL. Interpretive Summary: The abstract is for the Herbert J. Dutton Award lecture which will be presented at the AOCS meeting as part of the analytical division luncheon. The lecture will include the review of my recent research in castor oil analysis. Ricinoleate, a monohydroxy fatty acid in castor oil, has many industrial uses. Ricinoleate occurs as acylglycerols in castor oil which is the only commercial source of ricinoleate. About 30 molecular species of acylglycerols containing ricinoleate and/or dihydroxy fatty acids have been identified and quantified in castor oil. The contents of fatty acids at the different locations on the glycerol backbone of many molecular species of triacylglycerols have been determined. The information could help to understand the biosynthesis of acylglycerols containing mono- and dihydroxy fatty acids as well as to develop the industrial uses.
Technical Abstract: Ricinoleate, a monohydroxy fatty acid, has many industrial uses such as the manufacture of aviation lubricant, plastic, paint and cosmetics. Ricinoleate occurs as acylglycerols (AG) in castor oil, and about 70% of castor oil is triricinolein. Castor oil is the only commercial source of ricinoleate. We have earlier identified and quantified 14 molecular species of AG containing ricinoleate in castor oil using HPLC and MS. We have recently identified 2-(12-ricinoleoylricinoleoyl)-1,3-diricinoleoyl-sn-glycerol (RRRR) and 12 AG containing dihydroxy fatty acids in castor oil. The structures of the three newly identified dihydroxy fatty acids were proposed as 11,12-dihydroxy-9-octadecenoic acid, 11,12-dihydroxy-9,13-octadecadienoic acid and 11,12-dihydroxyoctadecanoic acid. The regiospecific ratios of the molecular species of triacylglycerols (TAG) were also estimated. For diricinoleoylacylglycerols in castor oil, the non-hydroxy fatty acid is predominately at the sn-2 position. For RRRR, ricinoleoylricinoleoyl chain is predominately at the sn-2 position. For TAG containing dihydroxy fatty acids, dihydroxy fatty acids are predominately at the sn-1,3 positions.