Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 2/10/2009
Publication Date: 2/2/2010
Citation: Lin, J.T. 2010. Molecular species of diacylglycerols and triacylglycerols containing dihydroxy fatty acids in castor oil. In:Hou, C.T. and Shaw, J.F., editors. Hoboken, NJ: John Wiley & Sons. p. 377-389. Interpretive Summary: Ricinoleate, a monohydroxy fatty acid in castor oil, has many industrial uses. Dihydroxy fatty acids and triacylglycerols containing dihydroxy fatty acids have different physical and chemical properties from those of monohydroxy fatty acids and normal fatty acids, and can be used in industry for either different or similar purposes to those of ricinoleate. We have identified twelve acylglycerols containing dihydroxy fatty acids in castor oil. The structures of the three dihydroxy fatty acids were proposed. The contents of fatty acids at the different locations on the glycerol backbone of triacylglycerols were determined. The information could help to understand the biosynthesis of acylglycerols containing dihydroxy fatty acids as well as to develop the industrial uses.
Technical Abstract: The identification of four molecular species of diacylglycerols and eight molecular species of triacylglycerols containing dihydroxy fatty acids in castor oil was reported. The structures of the three dihydroxy fatty acids were proposed as 11,12-dihydroxy-9-octadecenoic acid, 11,12-dihydroxy-9,13-octadecadienoic acid and 11,12-dihydroxyoctadecanoic acid. Ricinoleate was predominately at the sn-2 position of TAG (AAB and ABC) containing dihydroxy fatty acids and the dihydroxy fatty acids were mainly at the sn-1,3 position in castor oil. The AG containing dihydroxy fatty acids in castor oil can be isolated for industrial uses although the total content is low (about 2.5 %). The regiospecific identification of TAG affects the physical and chemical properties of the oil and it will help in developing the industrial uses of the oil.