Submitted to: Lipids
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/5/2008
Publication Date: 4/1/2009
Citation: Lin, J.T., Arcinas, A.J., Harden, L.A. 2009. Identification of acylglycerols containing dihydroxy fatty acids in castor (Ricinus communis L.)oil by mass spectrometry. Lipids. 44:359-365. Interpretive Summary: Ricinoleate, a monohydroxy fatty acid in castor oil, has many industrial uses. 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 different purpose. We have identified twelve acylglycerols containing dihydroxy fatty acids in castor oil. The structures of the three dihydroxy fatty acids were proposed. Dihydroxy fatty acids have not been previously identified in higher plants and microbial culture. They can be isolated from castor oil or produced from a transgenic plant for future industrial uses.
Technical Abstract: Ricinoleate, a monohydroxy fatty acid, in castor oil has many industrial uses. Dihydroxy fatty acids can also be used in industry. The C18 HPLC fractions of castor oil were used for mass spectrometry to identify the acylglycerols containing dihydroxy fatty acids. Four diacylglycerols identified were diOH18:1-diOH18:1, diOH18:2-OH18:1, diOH18:1-OH18:1 and diOH18:0-OH18:1. Eight triacylglycerols identified were diOH18:1-diOH18:1-diOH18:1, diOH18:1-diOH18:1-diOH18:0, diOH18:2-diOH18:1-OH18:1, diOH18:1-diOH18:1-OH18:1, diOH18:1-diOH18:0-OH18:1, diOH18:2-OH18:1-OH18:1, diOH18:1-OH18:1-OH18:1 and diOH18:0-OH18:1-OH18:1. The locations of fatty acids on the glycerol backbone were not determined. The structures of these 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 by MS3 or MS4 of HPLC fractions of castor oil. These individual acylglycerols were at the levels of about 0.2% or less in castor oil and can be isolated from castor oil or overproduced in a transgenic oil seed plant for future industrial uses.