Submitted to: International Symposium on Biocatalysis and Biotechnology: Functional Food and Industrial Products
Publication Type: Abstract Only
Publication Acceptance Date: 7/29/2012
Publication Date: 10/29/2012
Citation: Lin, J.T. 2012. Ratios of regioisomers of minor acylglycerols less polar than triricinolein in castor oil estimated by mass spectrometry and the biosynthesis of tetraacylglycerols in castor. International Symposium on Biocatalysis and Biotechnology: Functional Food and Industrial Products. Rohnert Park, California, 0.
Technical Abstract: We have recently reported the identification of forty new minor molecular species of acylglycerols containing hydroxy fatty acids less polar than triricinolein by electrospray ionization mass spectrometry of the lithium adducts. The ratios of regioisomers of triacylglycerols (ABC and AAB types) and tetraacylglycerols (AAAB type) identified were estimated by the relative abundances of the fragmentations from the neutral losses of fatty acids as a,(3-unsaturated fatty acids at the sn-2 position. The order of the contents of regioisomers of triacylglycerols with the fatty acids at the sn-2 position are: nonhydroxy fatty acids > monohydroxy fatty acids > dihydroxy fatty acids > trihydroxy fatty acids. For tetraacylglycerols (AAAB type) such as ricinoleoylricinoleoyl-ricinoleoyl-oleoyl-glycerol (RRRO), ricinoleoylricinoleoyl chain was predominately at the sn-2 position, while ricinoleate was not detected at the sn-2 position. The biosynthesis of tetraacylglycerols in castor was proposed. The acylation of ricinoleate to the hydroxyl group of ricinoleate at the sn-2 position of triacylglycerol to form tetraacylglycerol was preferred.