Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2010
Publication Date: 10/14/2010
Citation: Lin, J.T., Chen, G.Q. 2010. Acylglycerols Containing Trihydroxy Fatty Acids in Castor Oil and the Regiospecific Quantification of Triacylglycerols. Journal of the American Oil Chemists' Society. 87:1371-1379.
Interpretive Summary: Ricinoleate, a monohydroxy fatty acid in castor oil, has many industrial uses. Dihydroxy fatty acids and trihydroxy fatty acids have different physical properties, e. g., viscosity, pouring point, from those of ricinoleate. They can be used in manufacturing bio-products, such as lubricants, with different physical properties from those of ricinoleate. We report here the identification of diacylglycerols and triacylglycerols containing trihydroxy fatty acids in castor oil. The structures of the trihydroxy fatty acids were proposed.
Technical Abstract: Ricinoleate, a monohydroxy fatty acid in castor oil, has many industrial uses. Dihydroxy and trihydroxy fatty acids can also be used in industry. We report here the identification of diacylglycerols and triacylglycerols containing trihydroxy fatty acids in castor oil. The C18 HPLC fractions of castor oil were used for mass spectrometry of lithium adducts to identify trihydroxy fatty acids and the acylglycerols containing trihydroxy fatty acids. Two diacylglycerols identified were triOH18:1-diOH18:1 and triOH18:0-OH18:1. Four triacylglycerols identified were triOH18:1-OH18:1-OH18:1, triOH18:0-OH18:1-OH18:1, triOH18:1-OH18:1-diOH18:1 and triOH18:0-OH18:1-diOH18:1. The structures of these two newly identified trihydroxy fatty acids were proposed as 11,12,13-trihydroxy-9-octadecenoic acid and 11,12,13- trihydroxyoctadecanoic acid. The locations of these trihydroxy fatty acids on the glycerol backbone were almost 100% at the sn-1,3 positions or at trace levels at the sn-2 position. The content of these acylglycerols containing trihydroxy fatty acids was at the level of about 1%.