Abstract
Symmetrically structured triacylglycerols (TG) rich in docosahexaenoic acid (DHA) with caprylic acid (CA) at the outer positions were synthesized enzymatically form bonito oil in a two-step process: (i) ethanolysis of bonito oil TG to 2-monoacylglycerols (2-MG) and fatty acid ethyl esters, and (ii) reesterification of 2-MG with ethyl caprylate. Ethanolysis catalyzed by immobilized Candida antarctica lipase (Novozym 435) yielded 92.5% 2-MG with 43.5% DHA content in 2 h. The 2-MG formed were reesterified with ethyl caprylate by immobilized Rhizomucor miehei lipase (Lipozyme IM) to give structured TG with 44.9% DHA content [based on fatty acid composition with caprylic acid (CA) excluded] in 1 h. The final structured lipids comprised 85.3% TG with two CA residues and one original fatty acid residue, 13% TG with one CA residue and two original fatty acid residues, and 1.7% tricaprylolglycerol (weight percent). The amount of TG with two CA residues and one C22 residue (22∶6=DHA, 22∶5, and 22∶4) was 51 wt%. The 1,3-dicapryloyl-2-docosahexaenoylglycerol to 1,2(2,3)-dicapryloyl-3 (1)-docosahexaenoylglycerol ratio (based on high-performance liquid chromatography peak area percentages) was greater than 50∶1. The recovery of TG as structured lipids after silica gel column purification was approximately 71%. Ethyl esters and 2-MG formed at 2 h of ethanolysis could be used to determine the positional distribution of fatty acids in the intial TG owing to the high 1,3-regiospecificity of Novozym 435 and the reduced acyl migration in the system.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Gill, I., and R. Valivety, Polyunsaturated Fatty Acids, Part 1: Occurrence, Biological Activities and Applications, Tibtech 15:401–409 (1997).
Sadou, H., C.L. Leger, B. Descomps, J.N. Barjon, L. Monnier, and A. Crastes de Paulet, Differential Incorporation of Fish-Oil Eicosapentaenoate and Docosahexaenoate into Lipids of Lipoprotein Fractions as Related to Their Glyceryl Esterification: A Short-Term (postprandial) and Long-Term Study in Healthy Humans, Am. J. Clin. Nutr. 62:1193–1200 (1995).
Hedeman, H., H. Brøndsted, A. Mullertz, and S. Frokjaer, Fat Emulsions Based on Structured Lipids (1,3-specific triglycerides): An Investigation of the in Vivo Fate, Pharm. Res. 13:725–728 (1996).
Christensen, M.S., C.E. Høy, C.C. Becker, and T.G. Redgrave, Intestinal Absorption and Lymphatic Transport of Eicosapentaenoic (EPA), Docosahexaenoic (DHA), and Decanoic Acids: Dependence on Intramolecular Triacylglycerol Structure, Am. J. Clin. Nutr. 61:56–61 (1995).
Babayan, V.K., Medium Chain Triglycerides and Structured Lipids., Lipids 22:417–420 (1987).
Mascioli, E.A., B.R. Bistrian, V.K. Babayn, and G.L. Blackburn, Medium Chain Triglycerides and Structured Lipids as Unique Nonglucose Energy Sources in Hyperalimentation, ——Ibid. 22:421–423 (1987).
Endo, Y., S. Hoshizaki, and K. Fujimoto, Autoxidation of Synthetic Isomers of Triacylglycerol Containing Eicosapentaenoic Acid, J. Am. Oil Chem. Soc. 74:543–548 (1997).
Endo, Y., S. Hoshizaki, and K. Fijimoto, Oxidation of Synthetic Triacylglycerols Containing Eicosapentaenoic and Docosahexaenoic Acids: Effect of Oxidation System and Triacylglycerol Structure, ——Ibid. 74:1041–1045 (1997).
Shimada, Y., A. Sugihara, K. Maruyama, T. Nagao, S. Nakayama, H. Nakano, and Y. Tominaga, Production of Structured Lipid Containing Docosahexaenoic and Caprylic Acids Using Immobilized Rhizopus delemar Lipase, J. Ferment. Bioeng. 81:299–303 (1996).
Iwasaki, Y., J.J. Han, M. Narita, R. Rosu, and T. Yamane, Enzymatic Synthesis of Structured Lipids from Single Cell Oil of High Docosahexaenoic Acid Content, J. Am. Oil Chem. Soc. 76: 563–569 (1999).
Schmid, U., U.T. Bornscheuer, M.M. Soumanou, G.P. McNeill, and R.D. Schmid, Optimization of the Reaction Conditions in the Lipase-Catalyzed Synthesis of Structured Glycerides, ——Ibid. 75:1527–1531 (1998).
Laakso, P., W.W. Christie, and J. Pettersen, Analysis of North Atlantic and Baltic Fish Oil Triacylglycerols by High-Performance Liquid Chromatography with a Silver Ion Column, Lipids 25:284–291 (1990).
Rosu, R., M. Yasui, Y. Iwasaki, and Y. Yamane, Enzymatic Synthesis of Symmetrical 1,3-Diacylglycerols by Direct Esterification of Glycerol in Solvent-Free System, J. Am. Oil Chem. Soc. 76:839–843 (1999).
Becker, C.C., A. Rosenquist, and G. Hølmer, Regiospecific Analysis of Triacylglycerols Using Allyl Magnesium Bromide, Lipids 28:147–149 (1993).
Irimescu, R., K. Furihata, K. Hata, Y. Iwasaki, and T. Yamane, Utilization of Reaction Medium-Dependent Regiospecificity of Candida antarctica Lipase (Novozym 435) for Synthesis of 1,3-Dicapryloyl-2-docosahexaenoyl or Eicosapentaenoyl Glycerol, J. Am. Oil Chem. Soc. 78:285–289 (2001).
Haraldsson, G.G., and O. Almarsson, Studies on the Positional Specificity of Lipase from Mucor miehei During Interesterification Reactions of Cod Liver Oil with n−3 Polyunsaturated Fatty Acid and Ethyl Ester Concentrates, Acta Chem. Scand. 45:723–730 (1991).
Haraldsson, G.G., A. Halldorsson, and E. Kulås, Chemoenzymatic Synthesis of Structured Triacylglycerols Containing Eicosapentaenoic and Docosahexaenoic Acids, J. Am. Oil Chem. Soc. 77:1139–1145 (2000).
Irimescu, R., K. Hata, Y. Iwasaki, and T. Yamane, Comparison of Acyl Donors for Lipase-Catalyzed Production of 1,3-Dicapryloyl-2-eicosapentaenoylglycerol, ——Ibid. 78:65–70 (2001).
Author information
Authors and Affiliations
Corresponding author
About this article
Cite this article
Irimescu, R., Furihata, K., Hata, K. et al. Two-step enzymatic synthesis of docosahexaenoic acid-rich symmetrically structured triacylglycerols via 2-monoacylglycerols. J Amer Oil Chem Soc 78, 743–748 (2001). https://doi.org/10.1007/s11746-001-0336-6
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s11746-001-0336-6