|Turner, Charlotta - FAS|
Submitted to: Biochemistry & Molecular Biology of Plant Fatty Acids and Glycerolipids
Publication Type: Abstract Only
Publication Acceptance Date: July 20, 2003
Publication Date: November 20, 2003
Citation: TURNER, C., NGUYEN, T.T., LIN, J.T., WONG, R.Y., HARDEN, L.A., LUNDIN, R.E., MCKEON, T.A. LIPASE-CATALYZED SYNTHESIS OF 1,2(2,3)-DIRICINOLEIN.. BIOCHEMISTRY & MOLECULAR BIOLOGY OF PLANT FATTY ACIDS AND GLYCEROLIPIDS. LIPIDS, v. 38(11)2003, pp:1197-1205 Technical Abstract: 1,2(2,3)-diacylglycerols of ricinoleate are difficult to synthesize using conventional organic methodologies. An alternative form of catalysts is lipases, which enable higher specificity of the reaction. In this work, 1,2(2,3)-diricinolein was synthesized from triricinolein using a lipase from Penicillium roquefortii. This lipase is highly specific towards tri- and monoacylglycerols, but shows almost no activity towards diacylglycerols. The methanolysis reaction was performed in diisopropyl ether at a water activity of 0.53. These reaction conditions were chosen after investigating four different lipases: Candida antarctica type B, Rhizomucor miehei, Pseudomonas cepacia and Penicillium roquefortii, two reaction solvents: n-Hexane and diisopropylether, and three water activities: 0.11, 0.53, and 0.97. The consumption of triricinolein and the formation of ricinoleic acid, methyl ricinoleate, 1,2(2,3)-diricinolein and 1,3-diricinolein was followed for reactions of up to 48 hours. The compounds were quantified on RP-HPLC, and 1,2(2,3)-diricinolein was identified using ESI-LC-MS and its purity was determined by H- and C-NMR. The developed enzymatic synthesis method gave 88% yield of diricinolein, and this peak could easily be fractionated from the reaction mixture using preparative HPLC. The purity of the fraction collected diricinolein peak was 82% 1,2(2,3)-diricinolein (18% was 1,3-diricinolein). Hence, 41% of the enzymatically synthesized diricinolein was composed of the 1,2-isomer. This compound is useful as a substrate for characterizing the specificity of diacylglycerol acyltransferase (DGAT) enzymes.